US20160238280A1

US20160238280A1 - Catalytic Heating System and Method for Heating a Beverage or Food

Info

Publication number: US20160238280A1
Application number: US15/088,059
Authority: US
Inventors: Clifford G Welles; Noriko Welles
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-10-03
Filing date: 2016-03-31
Publication date: 2016-08-18

Abstract

A catalytic heating system for heating a beverage or food that comprises: a container for containing the beverage or food and a catalytic combustion assembly for heating the container, with the catalytic combustion assembly comprising a fuel supply assembly having a fuel canister for supplying a fuel gas having a stoichiometric ratio of about 15 to an air mixing injector for injecting the fuel gas into an elongate sidewall enclosure having curved shape and defining an enclosed catalytic combustion chamber where a catalytic combustion process is generated, causing the complete combustion of all of the fuel gas and heating the container containing the beverage or food.

Description

PRIORITY

This application is a continuation-in-part of U.S, application Ser. No. 14/988,526, filed on Dec. 31, 2015, which h a continuation of International Application No. PCT/US2015/38456. filed on Jun. 30, 2015. which claims the benefit of U.S. Provisional Application No. 60/059,510, filed on Oct. 3, 2014.

TECHNICAL FIELD

This application relates to the use of systems and methods for the generation of heat for use in heating portable containers containing beverages or food, and more specifically to systems and methods for the generation of catalytically produced heat within an enclosed catalytic combustion chamber for heating a container containing a beverage or food. Background Art
Portable heating systems, such as camping stoves and lanterns, are well known in the art of designing and manufacturing such systems. Camping stoves generally utilize an open or partially open flame to heat the stove's contents, with an aerosol canister containing a pressured fuel, typically butane or propane or a combination of those fuels, to supply the fuel needed to maintain the flame. Lanterns, on the other hand, operate similarly to produce light. These devices have several well-known limitations, with the most obvious being the use of an open flame and the fire danger it possess. Other less obvious limitations are related to the chemical characteristics of butane and propane.
The working pressure available from fuel canisters containing butane (either iso- butane or n-butane) or propane or a mixture of such gases is effected by variations in temperature that create conditions that are not ideal for operating heating or lighting systems over a wide range of ambient temperatures and altitudes Specifically, the useful working pressure for butane at lower ambient temperatures drops off significantly such that the proper operation of a heating or lighting device is impaired. Propane allows for operation at low ambient temperatures but requires a heavier and more expensive fuel canister to safely handle pressures that are normally encountered at higher ambient temperatures. Mixed fuel combinations of butane and propane have been developed to minimize the impact of pressure and temperature variation. But these combinations still suffer from a tendency of the more volatile components of the combined fuels, which have lower boiling points, to be used up sooner than the less volatile fuel components, resulting in unsatisfactory pressure remaining in the fuel canister as it is depleted, especially under cold conditions.
In addition to the limitations in using butane and propane to fuel an open flame device, butane and propane also have other significant limitations related to their potential use as a fuel source for a catalytic combustion process. An important characteristic for any fuel used in catalytic combustion is the light-off temperature, which is a rough indicator of the propensity for the fuel oxidation reaction to proceed. Light-off temperature is often defined as the temperature at which the conversion rate for the reactants reaches 50%, abbreviated as T₅₀. A low T₅₀assists in the complete conversion of the fuel to heat without producing intermediate reaction products and pollutants, which may occur when trying to operate the catalytic combustion process at relatively low temperatures. A sufficiently low T₅₀value will also allow for catalytic reactor designs that can use light weight metals such as aluminum without concern for exceeding material temperature limits or causing catalyst deterioration. The fuel gasses commonly, used such as butane and propane, all have relatively high T₅₀values, limiting the possible material design choices and catalytic reactor operating parameters for the heating catalytic combustion chamber. The higher operating temperatures may also introduce unwanted design choices necessary to insure safe operating conditions for the user. Prior art is deficient in describing means for insuring fail-safe operation of catalytic heating in a wide variety of circumstances. Irrespective of fuel type, the prior art does not show how to adapt catalytic heating, to applications, such as, self-heated: temperature regulated portable beverage heating or cooking applications in a manner that assures a high degree of operational safety using techniques that are cost effective. Prior art also does not show how compressed gas fuel used in catalytic heat generation can be safely applied to an indoor application or while inside a transport vehicle, or any small enclosure such as a tent. All of these shortcomings, as well as, others associated with prior art catalytic, heat generating devices, limit their applications or area of use.
In view of these and other problems in the prior art, it is a general object of the present invention to provide an improved apparatus and method utilizing a catalytic heat generating device that overcomes the drawbacks relating to the compromise designs of prior art devices as discussed above. Another object of the present invention is to provide a passive technique, which requires no externally provided power, for pre-mixing air and fuel which will provide air to fuel equivalence ratios of one or more when coupled to reactors that have relatively high back pressures.

SUMMARY DISCLOSURE OF THE INVENTION

A catalytic heating system for heating a beverage or food is presented that comprises: a container for containing the beverage or food, and a catalytic combustion assembly for heating the container that comprises: a chamber plate integral with the bottom of the container; an elongate sidewall enclosure integral with the chamber plate, with the elongate sidewall enclosure having a fuel gas inlet and an exhaust outlet within corresponding ends of the elongate sidewall enclosure, and with the elongate sidewall enclosure defining an enclosed catalytic combustion chamber; a catalytic reaction media disposed within the enclosed catalytic combustion chamber, a combustion starting element disposed within the enclosed catalytic combustion chamber; a fuel supply assembly mounted on a fuel supply platform, with the fuel supply assembly having a fuel and air mixing injector fluidly connected to the fuel gas inlet a fuel canister sealably connected to the fuel supply platform and fluidly connected to the fuel supply assembly; and a fuel gas contained within the fuel canister. And, a shell containing the container and catalytic combustion assembly forms the catalytic heating system for heating the beverage or food. In operation the fuel and air mixing injector within the catalytic heating system can entrain the fuel gas with air and inject a fuel gas and entrained air mixture into the enclosed catalytic combustion chamber where the combustion starting element can ignite the fuel gas and entrained air mixture, and the catalytic reaction media can maintain a catalytic combustion process within the enclosed catalytic combustion chamber, and the catalytic combustion process can combust all of the fuel gas and heat the container containing the beverage or food.
A method of heating a container is also presented that comprises: providing for a flow of a fuel gas, with the fuel gas having a stoichiometric ratio of about 15, increasing the velocity of the flow of the fuel gas; entraining the flow of the fuel gas with air, thereby creating a flow of fuel gas and entrained air mixture; maintaining an entrapment ratio of about 15 or above for the flow of fuel gas and entrained air mixture; constraining the flow of fuel gas and entrained air mixture to an enclosed curved path; contacting the flow of fuel gas and entrained air mixture with a catalytic reaction media; igniting the flow of fuel gas and entrained air mixture, thereby generating the catalytic combustion process; combusting all of the fuel gas during the catalytic combustion process; and conducting heat from the catalytic combustion process to the container.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top front perspective illustration of a catalytic heating system for heating a beverage or food.

FIG. 1B is a top back perspective view of the catalytic heating system.

FIG. 2 is the same perspective illustration as in FIG. 1A, with portions of an outer shell and a container removed, showing the bottom of the container for containing a beverage or food and a catalytic combustion assembly.

FIG. 3 is an exploded side view of the catalytic heating system, showing the outer shell, the container for containing the beverage or food, and the catalytic combustion assembly comprising a top chamber plate integral with the bottom of the container, a bottom chamber plate, a fuel supply assembly, a fuel supply platform and a fuel canister.

FIG. 4 is a bottom perspective view of the container for containing a beverage or food that more specifically illustrates the top chamber plate integral with the bottom of the container.

FIG. 5A is an exploded top perspective view of the top chamber plate and the bottom chamber plate, illustrating that a catalytic combustion chamber can be formed when the top and bottom chamber plates are coupled together.

FIG. 5B is an exploded bottom perspective view of the top chamber plate and the bottom chamber plate, also illustrating that the catalytic combustion chamber can be formed when the top and bottom chamber plates are coupled together.

FIG. 5C is a partial side view of the top and bottom chamber plates that have been coupled together, forming the catalytic combustion chamber.

FIG. 5D is a cross-sectional view of FIG. 5C, providing a view in the direction indicated by the arrows 5D-5D in FIG. 5C.

FIG. 5E is a top plan view of FIG. 5C with the top chamber plate removed, providing a view in the direction indicated by the arrows 5E-5E in FIG. 5C.

FIG. 6A and FIG. 6B illustrate a catalytic combustion chamber having a serpentine shape and having a coiled shape, respectively.

FIG. 7A and FIG. 7B are top perspective and top plan views, respectively, of the fuel supply assembly mounted on the fuel supply platform.

FIG. 8 is a cross-sectional side view of the fuel supply platform and the fuel canister releasably attached to the fuel supply platform.

FIG. 9A and 9B are top and bottom perspective views, respectively, of a shell lid.

FIG. 10A is a top front perspective illustration of another embodiment of the catalytic heating system for heating a beverage or food,

FIG. 108 is a top back perspective view of the other embodiment of the catalytic heating system.

FIG. 10C is a top front perspective view of the other embodiment of the catalytic heating system, illustrating that the system can be separated into an upper shell module and a bottom shell module.

FIG. 11 is the same perspective illustration as in FIG. 10A, with portions of the upper shell module and lower shell module removed, illustrating a container and a catalytic combustion assembly.

FIG. 12 is an exploded side view of the other embodiment of the catalytic heating system, showing the upper and lower shell modules, the container for containing the beverage or food, and the catalytic combustion assembly comprising a top chamber plate coupled to a bottom chamber plate, a fuel supply assembly, a fuel supply platform and a fuel canister.

FIG. 13 is a bottom perspective view of the container for containing a beverage or food that more specifically illustrates that the bottom of the container is a fiat surface, with the top chamber plate not being an integral part of the container.

FIG. 14A is an exploded top perspective view of a top chamber plate and a bottom chamber plate, illustrating that a catalytic combustion chamber can be formed when the top and bottom chamber plates are coupled together.

FIG. 14B is an exploded bottom perspective view of the top chamber plate and bottom chamber plate, also Illustrating that the catalytic combustion chamber can be formed when the top and bottom chamber plates are coupled together.

FIG. 14C is a partial side view of the top and bottom chamber plates that have been coupled together, forming the catalytic combustion chamber,

FIG. 14D is a cross-sectional view of FIG. 14C, providing a view in the direction indicated by the arrows 14D-14D in FIG. 14C.

FIG. 14E is a top plan view of FIG. 14C with the top chamber plate removed, providing a view in the direction indicated by the arrows 14E-14E in FIG. 14C.

FIG. 15A and FIG. 15B are top perspective and top plan views, respectively, of the fuel supply assembly mounted on live fuel supply platform.

FIG. 16 is a cross-sectional side view of the fuel supply platform and the fuel canister releasably attached to the fuel supply platform

FIG. 17A and 17B are top and bottom perspective views, respectively, of a shell lid.

FIG. 18 is a graphical representation of minimum useful ambient operating temperature as a function of percentage of fuel remaining in a fuel canister at sea level.

FIG. 19A and 19B are top front and top back perspective illustrations of another embodiment of the catalytic heating system for heating a beverage or food, with the heating provided by a stovetop surface.

FIG. 20 is a partial cutaway top front perspective view of the embodiment of the catalytic heating system generally illustrated in FIG. 19A and FIG. 19B.

FIG. 21 is an exploded side view of the embodiment of the catalytic heating system generally illustrated in FIG. 19A and FIG. 19B.

FIG. 22A is an exploded top perspective view of a portion of the catalytic heating system generally illustrated in FIG. 19A and 19B, and further illustrating that a catalytic combustion chamber can be formed when top and bottom chamber plates are coupled together.

FIG. 22B is an exploded bottom perspective view of a portion of the catalytic heating system generally illustrated in FIG. 19A and 19B, and further illustrating that the catalytic combustion chamber can be formed when the top and bottom chamber plates are coupled together.

FIG. 22C is a partial side view of a portion of the catalytic heating system generally illustrated in FIG. 19A and FIG. 19B, and further illustrating the top and bottom chamber plates coupled together to form the catalytic combustion chamber.

FIG. 22D is a cross-sectional view of FIG. 22C, providing a view in the direction indicated by the arrows 22D-22D in FIG. 22C,

FIG. 22E is a top plan view of FIG. 22C with the top chamber plate removed, providing a view in the direction indicated by the arrows 22E-22E in FIG. 22C.

FIG. 23A and FIG. 23B are top perspective and top plan views, respectively, of a portion of the catalytic heating system generally illustrated in FIG. 19A and 19B, and further illustrating a fuel supply assembly mounted on a fuel supply platform.

FIG. 24 is a cross-sectional side view of a portion of the catalytic heating system generally illustrated in FIG. 19A and 19B, and further illustrating a fuel canister releasably attached to the fuel supply platform.

FIG. 25 is a top front perspective view of the catalytic heating system generally illustrated in FIG. 19A and 19B, and further illustrating a pot placed on a stovetop surface integral with the top chamber plate.

FIG. 26 is a top front perspective illustration of another embodiment of the catalytic heating system for heating a beverage or food, with the heating provided by a stovetop surface.

FIG. 27 is a partial cutaway top front perspective view of the embodiment of the catalytic heating system generally illustrated in FIG. 26.

FIG. 28 is an exploded side view of the embodiment of the catalytic heating system generally illustrated In FIG. 26.

FIG. 29A is an exploded top perspective view of a portion of the catalytic heating system generally illustrated in FIG. 26, and further illustrating that a catalytic combustion chamber can be formed when top and bottom chamber plates are coupled together.

FIG. 29B is a top view of a portion of the catalytic heating system generally illustrated in FIG. 26, and further illustrating a top view of the bottom chamber plate.

FIG. 29C is a bottom perspective view of the catalytic heating system generally illustrated in FIG. 26, and further illustrating the bottom side of the bottom chamber plate.

FIG. 29D is an alternative embodiment to the top and bottom chamber plates illustrated in FIG. 29A through 29C.

FIG. 30A and FIG. 30B are top perspective and top plan views, respectively, of a portion of the catalytic heating system generally illustrated in FIG. 26, and further illustrating a fuel supply assembly mounted on a fuel supply platform.

FIG. 31 is a cross-sectional side view of a portion of the catalytic heating system, generally illustrated in FIG. 26, and further illustrating a fuel canister releasably attached to the fuel supply platform.

FIG. 32 is a top front perspective view of the catalytic heating system generally illustrated in FIG. 26, and further illustrating a pot placed on the stovetop surface integral with the top chamber plate.

FIG. 33 is a top front perspective illustration of another embodiment of the catalytic heating system for heating a beverage or food, with the heating provided by a stovetop surface.

FIG. 34 is a partial cutaway top front perspective view of the embodiment of the catalytic heating system generally illustrated in FIG. 33.

FIG. 35 is an exploded side view of the embodiment of the catalytic heating system generally illustrated in FIG. 33

FIG. 38A is an exploded top perspective view of a portion of the catalytic heating system generally illustrated in FIG. 33, and further illustrating that a catalytic combustion chamber can be formed when the top and bottom chamber plates are coupled together.

FIG. 36B is a top view of a portion the catalytic heating system generally illustrated in FIG. 33, and further illustrating a top view of the bottom chamber plate.

FIG. 36C is a bottom perspective view of a portion of the catalytic heating system generally illustrated in FIG. 33, and further illustrating the bottom side of the bottom chamber plate.

FIG. 37A and FIG. 37B are top perspective and top plan views, respectively, of a portion of the catalytic heating system generally illustrated in FIG. 33, and further illustrating a fuel supply assembly mounted on a fuel supply platform.

FIG. 38 is a cross-sectional side view of a portion of the catalytic heating system generally illustrated in FIG. 33, and further illustrating a fuel canister releasably attached to the fuel supply platform.

BEST MODE OF CARRYING OUT THE INVENTION

FIG. 1A and FIG. 18 illustrate a top front perspective view and a top back perspective view,, respectively, of a catalytic heating system 1 for heating a beverage or food, with the catalytic heating system 1 preferably being portable. More specifically. FIG. 1A illustrates that the catalytic heating system 1 comprises an outer shell 2 having a cylindrically shape, a shell lid 4 removably attached to the outer shell 2, a canister base 6 adjacent to the outer shell 2, an on/off button 8 on an outside surface of the outer shell 2, a pan of air vents 10 for providing air passages into the inside of the outer shell 2, and a plurality of screws 12 for attaching the outer shell 2 to a catalytic combustion assembly 18 disposed within the outer shell 2 The catalytic combustion assembly is described in detail below. And, FIG. 1B shows that the outer shell 2 also contains an exhaust outlet duct 14 for providing an exhaust passage from the inside of the outer shell 2 to atmosphere.
FIG. 2 and FIG. 3 illustrate that the outer shell 2 houses a container 16 for containing a beverage or food and the catalytic combustion assembly 18 for heating the container 16 and its contents. The figures also show that the catalytic combustion assembly 18 comprises, a top chamber plate 20 that can be integral with the bottom of the container 16; a bottom chamber plate 22 coupled to the top chamber plate 20, thereby forming an integrated chamber plate 25; a fuel supply platform 24; a fuel supply assembly 26 having tubular connections to the fuel supply platform 24 and to the bottom chamber plate 22; a fuel canister 28 having the canister base 8 attached to a bottom of the fuel canister 28, with the fuel canister 28 removably attached to the fuel supply platform 24; and dimethyl ether fuel gas 29 as the preferred fuel gas, contained in a state of compression within the fuel canister 28. For present purposes, a reference to a “fuel” or a “fuel gas” means fuel in a gaseous phase, unless indicated otherwise.
The container 16 and catalytic combustion assembly 18 can be secured to the outer shell 2 by bonding an outside top perimeter of the container 16 to an inside top perimeter of the outer shell 2. And, the fuel supply platform 24 can be secured to the outer shell 2 by using the plurality of screws 12 to attach an inside perimeter of the outer shell 2 to an outside perimeter of the fuel supply platform 24. The shell lid 4 can be removably attached to a top end of the outer shell 2 by screwing the shell lid 4, having female threads around its inside perimeter, to the outer shell 2, having male threads around its top outside perimeter. The container 16 can be any container that can conduct heat, such as a cup, mug or sauce pan; preferably the container will have a metallic composition. And, the outer shell 2 can be made of a thermally non-conductive material, preferably a polymeric material; alternatively, the container 18 can have a thermally insulating layer disposed between a sidewall 17 of the container 16 and the outer shell 2.
The components of the catalytic combustion assembly 18 are illustrated in more detail in FIG. 4 through FIG. 8. The container 16 can be sized such that the top chamber plate 20 can be attached to the bottom of the container 16, and in a preferred embodiment, as best shown in FIG. 4, the top chamber plate 20 is integral with the bottom perimeter of the container , thereby eliminating a seam that would be formed, if the top chamber plate 20 were not integral with the bottom of the container 16, but instead was attached in some manner to the bottom perimeter of the container 16. FIG. 4 and FIG. 5A through FIG. 5E further illustrate that a bottom surface of the top chamber plate 20 contains an top channel 20A, also shown in FIG. 2. that is integral with the top chamber plate 20 and preferably has a concave half-cylindrically shape that extends partially above the top surface of top chamber plate 20, with the top channel 20A also having a curved center section 20B and a pair of linear sections 20C integral with corresponding ends of the curved center section 208 A top surface of the bottom chamber plate 22 similarly contains a bottom channel 22A that is integral with the bottom chamber plate 22 and preferably has a concave half-cylindrically shape that extends partially below the bottom surface of bottom chamber plate 22, with the bottom channel 22A having a curved center section 22B and a pair of linear sections 22C integral with corresponding ends of the curved center section 22B. When top and bottom chamber plates, 20 and 22, are aligned in a predetermined manner and coupled together to form the integrated chamber plate 25, top channel and bottom channel, 20A and 22A, form an elongate sidewall enclosure 32, having a preferred cylindrically shape, a curved sidewall center section 32A and a pair of linear sidewall end sections 32B integral with corresponding ends of the curved sidewall center section 32A. The elongate sidewall enclosure 32 encloses and defines an enclosed catalytic combustion chamber 30 that extends through the elongate sidewall enclosure 32, with the chamber 30 having the same curved and linear shape as the elongate sidewall enclosure 32. The elongate sidewall enclosure 32 and the enclosed catalytic combustion chamber 30 are best illustrated in FIG. 5C through FIG. 5E. The side view of FIG. 5C illustrates the top and bottom chamber plates, 20 and 22, after they have been coupled together forming the integrated chamber plate 25; the cross-sectional view of FIG. 5D shows the enclosed catalytic combustion chamber 30 enclosed within the elongate sidewall enclosure 32, with a catalytic reaction media 40 and a combustion starting element 50 (described below) removed; and the top plan view of FIG. 5E, with the top chamber plate 20 removed, further illustrates the enclosed catalytic combustion chamber 30, elongate sidewall enclosure 32 and the curved sidewall section 32A and pair of linear sidewall sections 32B, also with the catalytic reaction media 40 and combustion starting element 50 removed.
The elongate sidewall enclosure 32 preferably should have a diameter that is relatively small in order to ensure that the curved portion of the sidewall enclosure 32 can bend in a smooth and continuous fashion within the coupled chamber plates 20 and 22; and in order to more evenly distribute the heat generated from the enclosed catalytic combustion chamber 30 to the top chamber plate 20 that forms the bottom of the container 16 which, in turn, provides for a more even distribution of heat to the beverage or food. At the same time, however, the elongate sidewall enclosure 32 should have a diameter and total length that are large enough to contain a sufficient quantity of catalytic reaction media 40 over the length of the elongate sidewall enclosure 32 to produce a sufficient amount of heat to effectively heat the top chamber plate and the beverage or food within container 16. Given these considerations, the inventors have determined that the elongate sidewall enclosure 32 preferably should have a diameter of about 10 millimeters or less, and more preferably between about 5 and 10 millimeters. The elongate sidewall enclosure 32 also has a flow-through fuel gas inlet 32C within one end of the sidewall enclosure 32 and a flow-through exhaust outlet 32D within the other end of the sidewall enclosure 32, with the sidewall enclosure 32 having no other flow-through openings within the sidewall enclosure 32. And, as shown in FIG. 5A and FIG. 5B a flow-through fuel gas inlet elbow 34 and a flow-through exhaust outlet elbow 36 are sealably disposed within the flow-through fuel gas inlet 32C and the flow-through exhaust outlet 320. respectively. The flow-through exhaust outlet elbow 36 also has a tubular connection 37 with the exhaust outlet duct 14 within the outer shell 2. The tubular connection 37 effectively extends the enclosed length of the elongate sidewall enclosure 32 from the flow-through exhaust outlet 320 of sidewall enclosure 32 to the exhaust outlet duct 14.
It is preferred that the top and bottom chamber plates, 20 and 22, can be coupled together by utilizing a plurality of binder posts 3B, with top portions of the binder posts 38 disposed within corresponding openings the top chamber plate 20, with bottom portions of the binder posts 38 disposed within corresponding openings through the bottom chamber plate 22, and with bottom ends of the binder posts 38, which extend away from the bottom surface of the bottom chamber plate 22, used to couple the top chamber plate 20 to the bottom chamber plate 22 by flattening the ends of the binder posts 38 against the bottom surface of the chamber plate 22. Preferably, the top and bottom chamber plates. 20 and 22, have a metallic composition.
Before the enclosed catalytic combustion chamber 30 is formed by coupling the top and bottom chamber plates, 20 and 22, the catalytic reaction media 40 preferably can be positioned in a curved orientation, as shown in FIG. 5A, within the curved section 22B of bottom channel 22A. Alternatively, the catalytic reaction media 40 can be positioned in a curved and linear orientation within the curved section 22B of bottom channel 22A and within the pair of linear sections 22C of bottom channel 22A. Although the figure shows that a center top half of the catalytic reaction media 40 has been removed, this is only for the purpose of revealing a curved passage 42 that extends lengthwise through the interior of the catalytic reaction media 40. As also shown in FIG. 5A and FIG. 5B, a combustion starting element 50, preferably made from a narrow gage resistance wire alloy, such as Nichrome 60. Nichrome 80 or Kanthal, can be disposed lengthwise through a center portion of the catalytic reaction media 40, with one end 50A of the combustion starting element 50 disposed through an opening within the curved bottom channel 22A and another end SOB of the starting element 50 disposed through another opening through the curved bottom channel 22A, and with a center portion 50C of the combustion starting element 50 disposed through the curved passage 42 within the catalytic reaction media 40. Preferably, as illustrated in FIG. 5A. the center portion 50C of the combustion starting element 50 is coiled, which causes the combustion starting element 50 to attain a higher ignition temperature for a given amount of electrical power than would otherwise exist if the combustion starting element 50 were not coiled. The ends, 50A and 50B, of the combustion starting element 50 are in electronic connection with a programmed microprocessor 60 which, when activated, supplies electrical current from a battery 76, such as a lithium polymer type battery, to the combustion starting element 50. Alternatively, the combustion starting element 50 can be a spark ignition system comprising a pair of wires disposed within a lengthwise opening within the catalytic reaction media 40, with the pair of wires separated by a predetermined distance within the opening. A large transient electric voltage is formed between the wires using techniques well known to those skilled in the art such as utilizing a piezoelectric crystal that can produce a substantial voltage when squeezed by mechanical means. The resulting large voltage causes the discharge of a spark between the pair of wires that ignites the catalytic reaction media 40. And, as shown in FIG. 5A through FIG. 5E, in order to ensure that the catalytic combustion process is confined to the enclosed catalytic combustion chamber 30, sealing members 52 and 54 can be disposed within corresponding seating channels 52A and 54A within the top surface of the bottom chamber plate 22, with the sealing channel 52A concentrically positioned outside of bottom channel 22A and sealing channel 54A concentrically positioned Inside of bottom channel 22A. In addition, a pair of O-rings 56 can be utilized to further ensure that the catalytic combustion process is confined to the enclosed catalytic combustion chamber 30, with one of the pair O-rings 58 disposed around a portion of flow-through fuel gas Inlet elbow 34 and the other O-ring disposed around a portion of the flow-through exhaust outlet elbow 36.
Once the catalytic reaction media 40 and combustion element 50 are positioned within the curved bottom channel 22 A and the top chamber plate 20 is coupled to the bottom chamber plate 22, the catalytic reaction media 40 and the combustion element 50 are captured in a curved orientation within the curved sidewall section 32A of the elongate sidewall enclosure 32, thereby defining the enclosed catalytic combustion chamber 30 as having the same shape as the elongate sidewall enclosure 32 In this regard, a curved elongate shape for the enclosed catalytic combustion chamber 30 is preferred in order to more evenly distribute the heat from the combustion chamber 30 to the top chamber plate 20 and, thereby, provide for a more even distribution of heat to the beverage or food within container 16. And, the most preferred curved elongate shape for the enclosed catalytic combustion chamber 30 is a curvature having a constant radius of curvature (hereinafter referred to as a “circular curvature”), providing a smooth and continuous surface within the combustion chamber 30. Although the enclosed catalytic combustion chamber 30 having a circular curvature is preferred, other curved catalytic combustion chamber shapes could be utilized. For example, a serpentine shape within a chamber plate 25′, as illustrated in FIG. 6A, or a coiled shape within a chamber plate 25″, as shown in FIG. 6B, have shapes that are similarly smooth and continuous.
While there are several types of catalytic reaction media known in the art, the catalytic reaction media 40 preferably is an open cell metal foam substrate, combined with a wash coat and an active catalyst. It has been discovered that the use of an open cell metal foam substrate constructed from an iron, chromium, aluminum and yttrium alloy, under the trade name Fecralloy® or Kanthal® and manufactured by Porvair, Inc., provides an ideal substrate material for the catalytic reaction media 40. Metal foam substrates tend to have very high surface area to volume ratios and very high porosities. The first property is important to enhance the number of catalyst sites per unit volume, which affects the catalytic space velocity (i.e. quotient of the entering volumetric flow rate of the reactants divided by the reactor volume) in the enclosed catalytic combustion chamber 30 and the second property helps to minimize the pressure drop within the enclosed catalytic combustion chamber 30. The particular type of metal foam fabrication technique is important in determining the properties that make for an optimum catalyst media. Metal foams can be constructed by several techniques such as sintering or investment casting. The heat transport properties of metal foams made by sintering are very different than those made by investment casting and are far less costly. Sintered metal foams, such as the ones manufactured by Porvair Inc., have a unique micro-structure that resembles interconnected open cells in the shape of dodecahedrons. The cells are constructed of a series of interconnected metal struts. A cross-section of each strut would show it to be a hollow shell. The resulting light mass allows the material to reach high temperatures with very little energy input. This in turn helps to minimize the energy required by the starter filament to start the reaction. The metal substrate is traditionally given a wash-coat of some very high surface area material (e.g. gamma alumina) upon which a catalyst is deposited (e.g. Platinum). The Fecralloy® alloy contains aluminum, which under a suitable heat treatment will be driven to the surface where it is converted to alumina when exposed to a high temperature oxidizing atmosphere. The conversion to alumina provides a bonding interface if an alumina wash coat is utilized. However, it has been discovered that two additional properties exist that can be used advantageously when the Fecralloy® alloy is used as the catalytic reaction media 40. The first property is that the self-generating aluminum oxide film can act as its own wash coat, albeit of less surface area than a traditional gamma alumina wash coat. In some catalytic reactor designs this may provide an adequate catalyst site attachment points and consequently sufficient catalyst activity levels. By eliminating the traditional wash-coat step, costs are reduced. The second surprising additional property is that the Fecralloy material, after heat treating to induce a native film of aluminum oxide, appears to have a certain amount of inherent catalytic activity on its own, without adding additional catalysts. This further reduces costs by reducing the amount of additional catalyst required to attain a specific space velocity. Although alumina coated cell foam substrates coaled with an active catalyst are preferred, other catalytic reaction can also be used. For instance, free standing porous alumina substrates coated with an active combustion catalysts or flow-through monoliths such as wash coated cordierite with and active catalyst coating could be used as well.
FIG. 7A and FIG. 7B more specifically illustrate the fuel supply assembly 26 that is mounted on a topside of the fuel supply platform 24. The fuel supply assembly 26 comprises the following fuel supply components: a fuel gas compression fitting 62 having a compression fitting and tap for use in fluidly connecting the fuel supply assembly 26 to the fuel canister 28, containing the dimethyl ether fuel gas 29; a liquid/gas separator 64, which could be, but not limited to, a porous oleophobic membrane such as “Supor R” made by Pall Corporation, having a tubular connection through tube 28A with the fuel gas compression fitting 62, with the liquid/gas separator 64 for removing any dimethyl ether fuel gas 29 that is in liquid form; a pressure regulator 66, such as an ultra-miniature regulator from the “PR-MIS” model series by Beswick Engineering, having a tubular connection through tube 26B with the liquid/gas separator 64, with the pressure regulator 66 for maintaining the pressure of the dimethyl ether fuel gas 29 at a predetermined level; a solenoid valve 68, such as the “LHL” series from the Lee Company, having a tubular connection through tube 26C with the pressure regulator 66, with the solenoid valve 68 for opening and dosing the flow of dimethyl ether fuel gas 29 through the fuel supply assembly 26; a fuel and air mixing injector 70, such as a venturi injector, having a tubular connection through tube 260 with the solenoid valve 88, with the fuel and air injector 70 for injecting the dimethyl ether fuel gas 29 and entrained air mixture into the enclosed catalytic combustion chamber 30; a temperature sensor 72A attached to the bottom surface of the bottom chamber plate 22 for sensing the temperature within the enclosed catalytic combustion chamber 30; and a temperature sensor 72B attached to the outside surface of the sidewall 17 of container 16 for sensing the temperature of the container 16. And, the fuel supply assembly 26 is connected to the enclosed catalytic combustion chamber 30 by inserting a top end of the fuel and air mixing injector 70 into the flow-through fuel gas inlet elbow 34 in tubular connection with the enclosed catalytic combustion chamber 30.
The fuel supply assembly 26 further comprises the programmed microprocessor 60 that is attached to and in electrical connection to a circuit board 74 that is mounted on the top side of the fuel supply platform 24. A battery 76, such as a lithium polymer type GM502030 from PowerStream Technology, Inc., can also be attached to and in electrical connection to the circuit board 74; or the battery 76 can be attached to any other appropriate location within the catalytic combustion assembly 18 or within the outer shell 2 surrounding the catalytic combustion chamber 18. The battery 76 supplies electrical power to the programmed microprocessor 60 when the on/off button 8 is in the “on” position and disconnects electrical power when the on/off button 8 is in the off position. When activated, the programmed microprocessor 60, with inputs from the temperature sensors 72A and 72B, controls the functionality of the solenoid valve 68 in order to control the fuel gas flow rate and temperature within the enclosed catalytic combustion chamber 30. The activated programmed microprocessor 60 also supplies electrical power to the combustion starting element 50, which the microprocessor 60 coordinates with the supply of fuel gas to the enclosed catalytic combustion chamber 30 by opening and closing the solenoid valve 68.
The cross-sectional side view presented in FIG. 8 illustrates that fuel canister 28 can contain the dimethyl ether fuel gas 29 and that the fuel canister 28 can be releasably connected to the fuel supply platform 24. In order to facilitate the connection, the fuel supply platform 24 comprises a platform receptacle 78, integral with an underside of the fuel supply platform 24, that contains a platform receptacle opening 80 leading to a cylindrically shaped cavity 82, with the cavity 82 having: female threads extending distally from the opening 80; an inner O-ring 84 disposed within the cavity 82 and positioned distally from the female threads; and an outer O-ring 86 disposed a round an outside surface of the platform receptacle 78. The fuel canister 28 contains a fuel flow valve 88, integral with the top of the fuel canister 28, and having male threads that can be used to connect the fuel canister 28 to the fuel supply platform 24 by screwing the fuel flow valve 88 into the platform receptacle 78. This action causes; 1) the tap within the fuel gas compression fitting 62 to open the fuel flow valve 88, thereby allowing the dimethyl ether fuel gas 29, which has been compressed within the fuel canister 28, to flow from the fuel canister 28 into the fuel supply assembly 26; and 2) an outside surface of the fuel canister 28 to engage the outer O-Ring 86 and the fuel flow valve 88 to engage the inner O-ring 84, thereby preventing dimethyl ether fuel gas 29 within the fuel canister 28 from escaping to atmosphere.
FIG. 9A and 9B illustrate in more detail that the top of the shell lid 4 contains a flow opening 4A for allowing a beverage contained within the container 16 to flow out of the container 16 and into a flow guide 4B for channeling the flow of a beverage from the container 16. A shell slider valve 4C can be operated within a shell slider valve retainer 4D to open the shell slider valve 4C in order to allow the beverage to flow out of the container 16 or to close the shell slider valve 4C to prevent the beverage from flowing out of the container 16.
Specifically, operation of the catalytic heating system 1 can proceed by providing a flow of the dimethyl ether fuel gas 29 by attaching the fuel canister 28, containing the dimethyl ether fuel gas 29, to the fuel supply platform 24, by screwing the fuel flow valve 88 into the platform receptacle 78, which causes the tap within the fuel gas compression fitting 62 to open the fuel flow valve 86 and causes the dimethyl ether fuel gas 29 within the fuel canister 28 to flow through compression fitting 62 and into the fuel supply assembly 26. The dimethyl ether fuel gas 29 will initially flow through the liquid/gas separator 64, where any fuel gas in liquid form will be removed, and then flow through the pressure regulator 66 that will maintain the fuel gas below a predetermined pressure, and continue flowing until it reaches the solenoid valve 68. With the on/off button 8 in the “off” position, the solenoid valve 68 will be closed, which prevents the dimethyl ether fuel gas 29 from flowing into the fuel and air mixing injector 70. Next the catalytic heating system 1 can be operated to heat a beverage or food by, if necessary, removing the shell lid 4 by unscrewing it from its engagement with the top of the outer shell 2. A beverage or food can then be placed into the container 16 and the shell lid 4 reattached to the outer shell 2. The catalytic combustion process that is utilized to heat the beverage or food is initiated by depressing the on/off button 8 to the “on” position, which activates the programmed microprocessor 80 by closing the circuit connection between the battery 78 and programmed microprocessor 60. At a predetermined time after activation, the programmed microprocessor 60 causes the solenoid valve 68 to open, causing the dimethyl ether fuel gas 29 to flow into the fuel and air mixing injector 70. As the dimethyl ether fuel gas 29 flows through the fuel and air mixing injector 70, the velocity of the fuel gas flow 29 will increase due to the distal narrowing of the injector 70. Increasing the velocity of the dimethyl ether fuel gas 29 causes the pressure in the fuel and air mixing injector 70 to decrease, thereby entraining the dimethyl ether fuel gas 29 with atmospheric air in order to produce a dimethyl ether fuel gas and entrained air mixture, while maintaining an entrapment ratio of about 15 or more parts air to about one part dimethyl ether fuel gas 29 for the mixture. The dimethyl ether fuel gas and the entrained air mixture is injected by the fuel and air mixing injector 70 into the flow-through fuel gas inlet elbow 34 and then into the elongate sidewall enclosure 32 defining the enclosed catalytic combustion chamber 30, thereby constraining the flow of the mixture though the enclosed catalytic combustion chamber 30 to the curved and linear path best illustrated in FIG. 5B. While the flow of the dimethyl ether fuel gas 29 and entrained air mixture is flowing through the enclosed catalytic combustion chamber 30, additional actions that contribute to the generation of the catalytic combustion process are: contacting the dimethyl ether fuel gas 29 and entrained air mixture with the catalytic reaction media 40 and the combustion starting element 50; activating the programmed microprocessor 60 to cause an electrical current to be supplied to the combustion starting element 50, which causes the combustion starting element 50 to heat up, thereby igniting the flow of dimethyl ether fuel and entrained air mixture and generating the catalytic combustion process within the catalytic reaction media 40 within enclosed catalytic combustion chamber 30. Importantly, this catalytic combustion process within the enclosed catalytic combustion chamber 30 can completely combust all of the dimethyl ether fuel gas 29. The heat generated by the catalytic combustion process causes the top channel 20A and top chamber plate 20 to heat up by conducting heat away from the catalytic combustion chamber: which in turn heats the container 18 and the beverage or food within the container 16. Exhaust generated from the catalytic combustion process passes through the flow-through exhaust outlet elbow 36. through the tubular connection 37 between the outlet elbow 36 and the exhaust outlet duct 14 within the outer shell 2, and out the exhaust outlet duct 14.
In addition to the advantages relating to the size and shape of the elongate sidewall enclosure 32 described above, the catalytic heating system 1 provides another beneficial feature related the combustion of the dimethyl ether fuel gas 29 and entrained air mixture within the enclosed catalytic combustion chamber 30. In particular, catalytic combustion process within the enclosed catalytic combustion chamber 30 is confined to the enclosed catalytic combustion chamber 30 defined by the elongate sidewall enclosure 32, with the only openings within the sidewall enclosure 32 being the flow-through fuel gas inlet 32C at one end of the sidewall enclosure 32 and the flow-through exhaust outlet 320 within the opposite end of the sidewall enclosure 32. This feature provides for a controllable and safe combustion process, including the feature of being able to safely transport all of the exhaust from the catalytic combustion through a single flow-through outlet to the environment outside of the catalytic heating system 1.
An inherent thermodynamically related limitation to the ability to achieve the complete combustion of all of the fuel gas in a catalytic combustion chamber is that the combustion process itself generates an amount of pressure in the chamber, generally referred to as “back pressure”, that can prevent complete combustion of the fuel gas. Other factors that can also contribute to an increase in back pressure are related to fluid mechanical limitations involving the geometry of the combustion chamber. In this regard, it is to be reasonably expected that a catalytic combustion process within the enclosed catalytic combustion chamber 30 within catalytic heating system 1 would produce more back pressure than would be expected from the catalytic process itself. This expected increase In back pressure is due to the unique geometry of the enclosed catalytic combustion chamber 30. defined by the partially curved and cylindrical shaped elongate sidewall enclosure 32, and due to the fact that the sidewall enclosure 32 has a single flow-through fuel gas inlet 32C and single flow-through exhaust outlet 32D, with no other flow-through openings within the sidewall enclosure 32. And, in fact, as will be described in more detail below, during the development of me catalytic heating system 1, the inventors determined that neither butane nor propane could be used to overcome the back pressure generated in the enclosed catalytic combustion chamber 30 and achieve the complete combustion of the fuel gas. Achieving complete combustion of the fuel gas in the enclosed catalytic combustion chamber 30 is important because incomplete combustion results in the inefficient utilization of the fuel gas and due to the fact that incomplete combustion can also release toxic substances into the environment and potentially inhaled by a user of the catalytic heating system 1.
From a fluid mechanics standpoint, one way to overcome back pressure and obtain complete combustion of the fuel gas within the enclosed catalytic combustion chamber 30 within the catalytic heating system 1 is to reduce the total amount of work energy required to overcome both the back pressure and the energy needed to carry large quantities of entrained air through the combustion chamber 30 and out the exhaust. A fixed amount of kinetic and potential energy is imparted to the fuel gas stream as it first enters the fuel and air mixing injector 70. The amount of energy the fuel gas stream obtains as it enters mixing injector 70 is dependent upon the fuel gas pressure, the density of the fuel gas, and the geometry (i.e. size and shape) of the mixing injector 70 orifice. With these principals in mind, the inventors of the catalytic heating system 1 carried out experiments to determine if complete combustion in the enclosed catalytic combustion chamber 30 could be attained using either butane or propane, which are the fuel gases used in other portable heating devices for heating beverages or food. In order to achieve a complete combustion of the butane fuel gas, the stoichiometric ratio of butane, about 32 parts of air to one part of fuel, requires the fuel and air mixing injector 70 to produce a butane fuel gas and entrained air mixture having an entrapment ratio also of about 32 or more parts of air to one part of fuel. Similarly, in order to achieve a complete combustion of the propane fuel gas, the stoichiometric ratio of propane, about 25 parts air to one part fuel, dictates that the fuel and air mixing injector 70 produce a propane fuel gas and entrained air mixture having an entrainment ratio also of about 25 parts or more of air to one part of fuel In their experiments, however, the inventors found that it was not possible to overcome back pressure and achieve complete combustion within the enclosed catalytic combustion chamber 30 using butane or propane as a fuel source. It was believed that this might have been due, at least in part, to the fact that attaining complete combustion using butane or propane as the fuel gas with the catalytic heating system 1 requires that air comprise a substantially greater percentage of the fuel gas and entrained air mixture due to the relatively high stoichiometric air to fuel ratios of these fuels. This in turn requires the fuel and air mixing injector 70 to provide relatively high entrainment ratios. The high entrainment ratios required by butane and propane contributes to a substantial increase in the work energy required to entrain air within the fuel and air mixing injector 70, leaving less energy available to perform the work necessary to flow the fuel and entrained air mixture through the enclosed catalytic combustion chamber 30. This explains, at least in part, the inability to overcome back pressures that can arise within the enclosed catalytic combustion chamber 30 when butane or propane is used as the fuel gas source.
A potential solution to this inability to overcome back pressure and achieve the complete combustion within the catalytic heating system 1 would be to use a different fuel having a lower stoichiometric ratio, allowing for a lower entrainment ratio required to achieve complete combustion in the enclosed catalytic combustion chamber 30. The ideal fuel gas would be one with a stoichiometric air to fuel ratio lower than the stoichiometric air to fuel ratios of butane or propane that would, therefore, give rise to less kinetic energy required to entrain air injected by the fuel and air mixing injector 70 into the enclosed catalytic combustion chamber 30, while still providing the same beneficial properties of butane and propane, such as being readily stored in a liquid state at pressures and temperatures compatible with portable consumer products. In fact the inventors experimentally determined that dimethyl ether fuel gas 29 unexpectedly produces sufficient kinetic energy of the fuel gas to entrain an adequate amount of air as it exits the fuel and air mixing injector 70 and still have sufficient amount of kinetic energy remaining to overcome back pressure and achieve complete combustion within the enclosed catalytic combustion chamber 30.
In order to achieve a complete combustion of the dimethyl ether fuel gas 28 within the enclosed catalytic combustion chamber 30, the stoichiometric ratio of the dimethyl ether, about 15 parts of air to one part of fuel, requires the fuel and air mixing injector 70 to produce a dimethyl ether fuel gas 29 and entrained air mixture that has an entrainment ratio of about 15 or more parts of air to one part of fuel. In this regard, given identical flow through conditions within the fuel and air mixing injector 70, the inventors determined that, based upon fluid mechanical principles, the exit velocities from the mixing injector 70 for all three gasses should be within about 10% of each other. Thus, the kinetic energy available for driving the flow of fuel gas and entrained air mixture through the enclosed catalytic combustion chamber 30 should be roughly similar for each gas. As a result, the inventors hypothesized that dimethyl ether might have enough kinetic energy available to outperform butane and propane and possibly be able to overcome enough back pressure within enclosed catalytic combustion chamber 30 to achieve the complete combustion of the dimethyl ether. In fact, in experiments carried out by the inventors, they confirmed that their hypothesis was correct in that the experiments demonstrated not only was the utilization of dimethyl ether able to overcome more back pressure than butane and propane but that the complete combustion of the dimethyl ether was surprisingly achieved in the combustion chamber 30 within the catalytic heating system 1. The specific results of the inventors' experiments are summarized in the Table I below:

TABLE I

COMPARISON OF EXCESS AIR WITH FIXED
VENTURI INJECTOR DESIGN UNDER IDENTICAL
REACTION CHAMBER CONDITIONS

	STOICHIO-
	METRIC	FUEL GAS
	AIR-FUEL	DENSITY
FUEL GAS	RATIO	(at STP)	EXCESS AIR

Dimethyl Ether
	15 to 1	2.055 [g/l]	Positive 10%
Butane	32.5 to 1	2.593 [g/l]	Negative 30%
Propane
	25 to 1	1.967 [g/l]	Negative 15%

As shown in the table, the inventors measured the quantity of air that was contained in the exhaust from using dimethyl ether, butane, and propane as the fuel gases that were combusted within in the catalytic combustion process within the catalytic heating system 1 as described above. In this regard, the specific dimensions for the cylindrical shaped elongate sidewall enclosure 32, enclosing and defining the enclosed catalytic combustion chamber 30, utilized in the experiments were the following: diameter=6.3 mm; radius of circular curvature=16.5 mm; length of circular curvature=50 mm; length of each linear section=4 mm; and overall length of the elongate enclosure from the fuel gas inlet to the exhaust outlet duct=85 mm. The catalytic combustion process utilizing dimethyl ether generated an exhaust containing about 10% more air than required to maintain a complete combustion of the dimethyl ether in the enclosed catalytic combustion chamber 30, establishing that all of tee dimethyl ether was combusted. The results for butane and propane, however, demonstrate that butane and propane generated 30% and 15% less air, respectively, than would have been required to completely combust those fuel gasses, meaning that not all of the butane or propane was completely combusted.
Another unexpected result of using dimethyl ether fuel gas 29 as the fuel source for the catalytic heating system 1 arises from thermodynamic considerations that pertain to light-off temperature, which is often defined as the temperature, often abbreviated as T₅₀, at which 50% of the fuel gas has been combusted within the combustion chamber. Since the light-off temperature of dimethyl ether is significantly lower than the light-off temperature of butane and propane, complete combustion of dimethyl ether in a catalytic combustion process occurs at a significantly lower temperature than either butane or propane, which also indicates that the complete combustion of dimethyl ether generates less back pressure that butane or propane. As a result the combination of a low entrainment ratio and a low light-off temperature can be expected to work together to reduce back pressure within the enclosed catalytic combustion chamber 30.
In addition, the ability to achieve complete combustion of the dimethyl ether fuel gas 29 in the enclosed catalytic combustion chamber 30 gives rise to another unexpected result related to potential flame propagation within the combustion chamber 30. In any catalytic reaction process within a combustion chamber it is important to limit or prevent flame generation inside or outside of the chamber. For example, if a combustible mixture of fuel gas and air were to accumulate in a region outside of the reaction chamber it would be desirable to Insure that no flame could be generated as a result of the catalytic reaction occurring within the reaction chamber. Similarly, if the temperature within the reaction chamber were to reach levels at or above the lowest temperature at which the fuel gas will spontaneously ignite without an external source for ignition, generally referred to as the “auto-ignition temperature”, flame propagation events could become more likely and should be prevented. In this regard, it has been reported that in order to achieve this result the chamber geometry should have certain dimensional relationships. In particular, reaction chambers, like the enclosed catalytic combustion chamber 30 that are elongated and cylindrical shaped, surprisingly provide the foundation for limiting or preventing flame propagation events. In this regard, an important parameter related to the shape of the reaction chamber is the critical flame quenching diameter. Cylindrical chambers with diameters below this critical value will not allow flames to propagate, and it is generally known that quenching diameters for most hydrocarbon fuels, including dimethyl ether, are in the range of about 10 millimeters or less for mixtures that have an air to fuel equivalence ration of between about 0.6 and 1.0 (e.g., Proceedings of the International Conference on Heat Transfer and Fluid Flow, Prague, Czech Republic. Aug. 11-12, 2014, Paper No. 36:“Quenching Distance and Quenching Diameter Ratio for Flame Propagating in Propane/Air mixtures”, by Arthur N. Gutkowski and Teresa Parra Santos). This critical flame quenching diameter unexpectedly overlaps the preferred diameter of the elongate enclosure 32 enclosing the combustion chamber 30 of between 5 and 10 millimeters. More specifically, by simply specifying that the elongate enclosure 32 preferably has a diameter of about between 5 and 10 millimeters, the catalytic heating system 1 is able to surprisingly achieve the unrelated favorable effects of: 1) an evenly distributed heating pattern for heating the beverage or food and simultaneously fill the enclosed catalytic combustion chamber 30 with a sufficient amount of catalytic reaction media 40 to achieve an adequate heating power to heat the beverage or food; and 2) preventing or limiting flame propagation within the enclosed catalytic combustion chamber 30.
Although dimethyl ether is known to be useful as a fuel source in some contexts, the fuel is not disclosed as a fuel source in a catalytic combustion application as disclosed by the catalytic heating system and 1. And, there are reasons why persons skilled in the art of open flame devices have utilized fuels like butane and propane; rather than dimethyl ether as a potential fuel gas source. One such reason is that dimethyl ether has an energy density of about 68,930 BTU/cubic foot, which is notably less than the energy densities of butane and propane, with butane having an energy density of about 94,000 BTU/cubic foot and propane having an energy density of about 84,250 BTU/cubic foot. Since devices for heating beverages and food have limited amounts of stored fuel gas, it is desirable to use fuel gases like butane and propane with high energy densities so that sufficient heating can be produced with a minimum amount of fuel. Dimethyl ether, with its lower energy density, would most likely not be considered as a suitable alternative. The inventors have surprisingly discovered, however, that due to the combination of dimethyl ether's relatively low light-off temperature, low stoichiometric air to fuel ratio, and a more ideal vapor pressure characteristic, these advantages outweigh the potential disadvantage of the lower energy density of dimethyl ether as a fuel gas utilized in the catalytic heating system and 1.
Another reason that dimethyl ether might not be considered as an acceptable fuel source is that ether compounds are generally known to have the characteristic of forming dangerous peroxide compounds when exposed to air. However, the inventors of the catalytic heating system 1 have determined that dimethyl ether does not exhibit that characteristic.
In addition to having a relatively low entrainment ratio and light-off temperature that combine to achieve complete combustion within the catalytic heating system 1, the utilization of dimethyl ether fuel gas 29 as the fuel source for the catalytic heating system 1 has other unexpected advantages over other fuel gases like butane and propane. One such advantage is that the use of the dimethyl ether fuel gas 29; allows the catalytic heating system 1 to be operated at altitudes above sea level, while still achieving complete combustion. This advantage can be implemented by setting the fuel and air mixing injector 70 to inject less fuel gas into the enclosed catalytic combustion chamber 30, causing the chamber 30 to receive a fuel gas and entrained air mixture having an entrainment ratio somewhat higher than the ratio needed for achieving complete combustion in the chamber 30 at sea level Although the “lean” fuel gas condition would prevent the consumption of all of the air injected into the chamber 30, complete combustion of the fuel gas would still be achieved. Then, as the catalytic heating system 1 is operated at increasingly higher altitudes above sea level, the fuel and air mixing injector 70 will increasingly deliver a richer mixture of air and fuel gas, until reaching an altitude where the mixture will produce a stoichiometric condition, where all of the air and fuel gas are being utilized in a complete combustion process within the enclosed catalytic combustion chamber 30. Fuel gases, such as butane and propane, that require a higher entrainment ratio at sea level than dimethyl ether will not be able to achieve a stoichiometric condition at an altitude as high as that achievable by dimethyl ether. Thus, the catalytic heating system 1 that utilizes the dimethyl ether fuel gas 29 as its fuel source is surprisingly more useful over a greater range of altitudes above sea level than other fuels having higher entrainment ratios.
The catalytic heating system 1 has still other surprising advantages over other devices that use butane or propane to heat beverages or food. Dimethyl ether has a useful working pressure at lower ambient temperatures than butane, thus, enhancing the usefulness of dimethyl ether in outdoor applications. And, although propane can be used at lower temperatures, it cannot be used in lighter weight and less expensive canisters mat comply with Department of Transportation regulation DOT 2Q but must be used in much heavier and more costly canisters. Dimethyl ether, on the other hand, can be used in canisters that comply with the regulation and at a lower cost.
In this regard, a common approach to improve the useful working pressure at lower ambient temperatures is to combine a mix of high and low boiling point liquefied gases. The graph depicted in FIG. 18 plots minimum useful ambient temperature as a function of percentage of fuel remaining in the canister at sea level, with “minimum useful temperature” being defined as the temperature below which the canister pressure is no longer sufficient to deliver the fuel gas at a suitable rate to the reaction chamber to obtain a targeted amount of heat power. Specifically, the graph illustrates that although mixed fuel gas formulations will provide good low temperature performance when the canister is full, the higher boiling point gas (i.e. propane) will leave the canister at a faster rate, eventually leaving behind mostly low boiling point gases (i.e. butane), Using pure propone or other similar high boiling point liquefied fuel gas would require much heavier and more expensive canisters. Canisters currently used by the aerosol industry would not provide an acceptable solution because propane's equilibrium vapor pressure exceeds both DOT and European safety specifications. The graph also shows, however, that dimethyl ether not only meets these specifications but provides both good low temperature performance and a steady performance as the canisters fuel is depleted.
The catalytic heating system 1 for heating a beverage or food is also substantially safer than flame based systems used for the same purposes. Flame based systems obviously present a potential that the open flame could ignite flammable objects in the environment. For example, if a flame based device tips over inside a camping tent, it will almost certainly start a fire inside the tent if the flame contacts a sleeping bag or clothing. Since the catalytic combustion process that takes place in the catalytic heating system 1 does not generate a flame and burns a much lower temperature than a flame based system, it is much less likely to start a fire under the same conditions.
Another surprising advantage of the catalytic heating system 1 is that the fuel supply assembly 26 and electronic components, comprising the programmed microprocessor 60 and battery 76, are all mounted on the fuel supply platform 24. The advantage of this feature is that when the fuel canister 28 releases the dimethyl ether fuel gas 29 into fuel supply assembly 26, the Joule-Thompson effect, which occurs during expansion of most gases, including dimethyl ether, cools the fuel supply assembly 28 and fuel supply platform 24, which, in turn, cool down the circuit board 74 containing the microprocessor 60 and battery 76. Consequentially, the distance between the fuel supply platform 24 and the bottom chamber plate 22 only needs to be sufficient to make room for the fuel supply assembly 26, without concern that the convective and radiant heat from the bottom chamber plate 22 will cause an overheating of the circuit board 74 and its electronic components. This cooling effect unexpectedly allows for a more compact design for the catalytic heating system 1.
In an another embodiment, a catalytic heating system 100 for heating a beverage or food as described is described in FIG. 10A through FIG. 17B. The primary difference between the catalytic heating system 100 and the catalytic heating system 1 is that m the catalytic heating system 1 the container 16 for containing a beverage or food is integral with the top chamber plate 20 within the catalytic combustion assembly 18, and the container is not intended to be used separately from the catalytic combustion assembly 18. However, in the catalytic heating system 100, a container 120 for containing a beverage or food is not integral with a catalytic combustion assembly 122 and is intended, if desired, to be used separately from the catalytic combustion assembly 122. With respect to the similarities between the figures illustrating catalytic combustion assemblies, 18 and 122, the only difference between the component parts illustrated in FIG. 5A through FIG. 5E and those illustrated in FIG. 14A through FIG. 14E is that the top channel 124A disclosed in FIG. 14A through FIG. 14E does not extend above the top surface of top chamber plate 124, which as a result is slightly thicker than top chamber plate 20A disclosed in FIG. 5A through 5E. With respect to the component parts of FIG. 15A through FIG. 17B, they are identical to FIG. 7A through 9B. And, although the component identification numbers for the corresponding sets of figures are not the same, the corresponding components are identical. For example, a fuel supply assembly 130 illustrated in FIG. 16A and FIG. 15B pertaining to the catalytic heating system 100 is identical to fuel supply assembly 26 illustrated in FIG. 7A and FIG. 7B pertaining to catalytic heating system 1.
FIG. 10A and 10B illustrate a top front perspective view and a top back perspective view, respectively, of a catalytic heating system 100 for heating a beverage or food, with the catalytic heating system 100 preferably being portable. More specifically, FIG. 10A illustrates that the catalytic heating system 100 comprises an upper shell module 102 having cylindrically shape and a lower shell module 104 also having a cylindrically shape. The catalytic heating system 100 further comprises a shell lid 108 removably attached to the upper shell module 102, a canister base 110 adjacent to the lower shell module 104, an on/oft button 112 on an outside surface of the lower shell module 104, a pair of air vents 114 providing air passages into the inside of the lower shell module 104, a plurality of screws 118 for attaching the lower shell module 104 to the catalytic combustion assembly 122 disposed within the lower shell module 104 as described below, and a snap-fit system 106 for releasably attaching the upper shell module 102 to the lower shell module 104. FIG. 10B illustrates that the lower shell module 104 contains an exhaust outlet duct 116 for providing an exhaust passage from inside of the lower shell module 104 to atmosphere. And, FIG. 10C shows more specifically that the snap-fit system 106 can be utilized to separate upper shell module 102 from the lower shell module 104. Snap-fit system 106 comprises a female portion 106A that is integral with a circumferential bottom portion 102A of the upper shell module 102 and a male portion 1068 that is integral with a circumferential band 104A integral with a top end of lower shell module 104. The snap-fit system 106 can be operated to detach the upper shell module 102 from the lower shell module 104 by depressing the male portion 1068, thereby releasing its engagement with the corresponding female portion 106A, and allowing the upper and lower shell modules, 102 and 104, to be separated. Then the separated modules can be reconnected by simply inserting circumferential band 104 of the lower shell module 104 into the circumferential bottom portion 102A of the upper shell module 102 until the female and male portions, 106A and 106B, reengage.
FIG. 11 and FIG. 12 illustrate that the upper shell module 102 houses a container 120 for containing a beverage or food and that the lower shell module 104 contains the catalytic combustion assembly 122 for heating the container 120 and its contents. The figures also show that the catalytic combustion assembly 122 comprises: a top chamber plate 124 that is not integral with the bottom of the container 120; a bottom chamber plate 128 coupled to the top chamber plate 124, thereby forming an integrated chamber plate 125; a fuel supply platform 128; a fuel supply assembly 130 having tubular connections to the fuel supply platform 128 and to the bottom chamber plate 126; a fuel canister 132 having the canister base 110 attached to a bottom of the fuel canister 132, with the fuel canister 132 removably attached to the fuel supply platform 128; and dimethyl ether fuel gas 127 as the preferred fuel gas contained in a state of compression within the fuel canister 132. As mentioned above, a reference to a “fuel” or a “fuel gas” means fuel in a gaseous phase, unless indicated otherwise.
The container 120 can be secured to the upper shell module 102 by bonding an outside top perimeter of the container 120 to an inside top perimeter of the upper shell module 102 and by similarly bonding an outside bottom perimeter of the container 120 to an inside bottom perimeter of the upper shell module 102. And, fuel supply platform 128 can be secured to the lower shell module 104 by using the plurality of screws 118 to attach an inside perimeter of the lower shell module 104 to an outside perimeter of the fuel supply platform 128. The shell lid 108 can be removably attached to a top end of the upper shell module 102 by screwing the shell lid 108, having female threads around its inside perimeter, to the upper shell module 102, having male threads around its top outside perimeter. The container 120 can be any container that can conduct heat, such as a cup, mug or sauce pan; preferably the container 120 will have a metallic composition. And, the upper and lower shell modules 102 and 104 can be made of a thermally non-conductive material, preferably a polymeric material; alternatively, the container 120 can have a thermally insulating layer disposed between a sidewall 121 of the container 120 and the upper shell module 102.
The components of the catalytic combustion assembly 122 are illustrated in more detail in FIG. 13 through 15. FIG. 13 illustrates that in this embodiment the top chamber plate 124 is not integral with the bottom of the container 120, with the container 120 having a flat container bottom 123 integral with the sidewall 121 of the container 120. FIG. 14A through 14E further illustrate that a bottom surface of the top chamber plate 124 contains a top channel 124A that is integral with the top chamber plate 124 and preferably has a concave half-cylindrically shape, with the top channel 124A also having a curved center section 124B and a pair of linear sections 124C integral with corresponding ends of the curved center section 124B. A top surface of the bottom chamber plate 126 similarly contains a bottom channel 120A, that is integral with the bottom chamber plate 126 and preferably has a concave half-cylindrically shape that extends partially below the bottom surface of bottom chamber plate 22, with the bottom channel 126A having a curved center section 126B and a pair of linear sections 126C integral with corresponding ends of the curved center section 126B. When top and bottom chamber plates, 124 and 126, are aligned in a predetermined manner and coupled together to form the integrated chamber plate 125, top channel and bottom channel, 124A and 126A, form an elongate sidewall enclosure 142, having a preferred cylindrically shape, a curved sidewall center section 142A and a pair of linear sidewall end sections 142B integral with corresponding ends of the curved sidewall center section 142A. The elongate sidewall enclosure 142 encloses and defines an enclosed catalytic combustion chamber 140 that extends through the elongate sidewall enclosure 142, with me chamber 140 having the same curved and linear shape as the elongate sidewall enclosure 142. The elongate sidewall enclosure 142 and the enclosed catalytic combustion chamber 140 are best illustrated in FIG. 14C through FIG. 14E. The side view of FIG. 14C illustrates me top and bottom chamber plates, 124 and 126, after they have been coupled together forming the integrated chamber plate 125; the cross-sectional view of FIG. 14D shows the catalytic combustion chamber 140 enclosed within the elongate sidewall enclosure 142, with a catalytic reaction media 160 and a combustion starting element 164 (described below) removed; and the top plan view of FIG. 14E, with the top chamber plate 124 removed, further illustrates the catalytic combustion chamber 140, elongate sidewall enclosure 142 and the curved sidewall section 142A and pair of linear sidewall sections 142B, also with the catalytic reaction media 160 and combustion starting element 164 removed.
The elongate sidewall enclosure 142 preferably should have a diameter that is relatively small in order to ensure that the curved portion of the sidewall enclosure 142 can bend in a smooth and continuous fashion within the coupled chamber plates 124 and 126; and in order to more evenly distribute the heat generated from the catalytic combustion chamber 140 to the top chamber plate 124 and to the bottom of the container 120 that is adjacent to the top chamber plate 124, which, in turn, provides for a more even distribution of heat to the beverage or food. At the same time, however, the elongate sidewall enclosure 142 should have a diameter and length that are large enough to contain a sufficient quantity of a catalytic reaction media 160 over the length of the sidewall enclosure 142 to produce a sufficient amount of heat to effectively the top chamber plate 124, bottom of the container 120 and the beverage or food within container 120. Given these considerations, the inventors have determined that the elongate sidewall enclosure 142 preferably should have a diameter of about 10 millimeters or less, and more preferably between about 5 and 10 millimeters. The elongate sidewall enclosure 142 also has a flow-through fuel gas inlet 142C within one end of the sidewall enclosure 142 and a flow-through exhaust outlet 142D within the other end of the sidewall enclosure 142, with the sidewall enclosure 142 having no other flow-through openings within the sidewall enclosure 142. And, a flow-through fuel gas inlet elbow 150 and a flow-through exhaust outlet elbow 152 are sealably disposed within the flow-through fuel gas inlet 142C and the flow-through exhaust outlet 142D, respectively. The flow-through exhaust outlet elbow 152 also has a tubular connection 153 with the exhaust outlet duct 116 within the lower shell module 104. The tubular connection 153 effectively extends the enclosed length of the elongate sidewall enclosure 142 from the flow-through exhaust outlet 142D of sidewall enclosure 142 to the exhaust outlet duct 116.
It is preferred that the top and bottom chamber plates, 124 and 126, are coupled together by utilizing a plurality of binder posts 154, with top portions of the binder posts 154 disposed within corresponding openings through the top chamber plate 124, with bottom portions of the binder posts 154 disposed within corresponding openings through the bottom chamber plate 126, and with bottom ends of the binder posts 154, which extend away from the bottom surface of the bottom chamber plate 126, used to couple the top chamber plate 124 to the bottom chamber plate 126 by flattening the ends of the binder posts 154 against the bottom surface of the chamber plate 126. Preferably, the top and bottom chamber plates, 124 and 126, have a metallic composition.
Before the enclosed catalytic combustion chamber 140 is formed by coupling the top and bottom chamber plates, 124 and 126, the catalytic reaction media 160 preferably can be positioned in a curved orientation, as shown in FIG. 5A, within the curved section 126B of bottom channel 126A. Alternatively, the catalytic reaction media 160 can be positioned in a curved and linear orientation within the curved section 126B of bottom channel 126A and within the pair of linear sections 126C of bottom channel 126A. Although the figure shows that a center top half of the catalytic reaction media 160 has been removed, this is only for the purpose of revealing a curved passage 182 that extends lengthwise through the interior of the catalytic reaction media 160. As also shown in FIG. 14A and 14B, a combustion starting element 164, preferably made from a narrow gage resistance wire alloy, such as Nichrome 60, Nichrome 80 or Kanthal, can be disposed lengthwise through a center portion of the catalytic reaction media 160, with one end 164A of the combustion starting element 164 disposed through an opening within the bottom channel 126A and another end 164B of the combustion starting element 164 disposed through another opening through the bottom channel 126A, and with a center portion 164C of the combustion starting element 164 disposed through the curved passage 162 within the catalytic reaction media 160. Preferably, as illustrated in FIG. 14A and 14B, the center portion 164C of the combustion starting element 164 is coiled, which causes the combustion starting element 164 to attain a higher ignition temperature for a given amount of electrical power than would otherwise exist if the combustion starting element 164 were not coiled. The ends, 164A and 164B, of the combustion starting element 164 are in electronic connection with a programmed microprocessor 166 which, when activated, supplies electrical current a battery 138, such as a lithium polymer type battery, to the combustion starting element 164. Alternatively, the combustion starting element 164 can be a spark ignition system comprising a pair of wires disposed within a lengthwise opening within the catalytic reaction media 164, with the pair of wires separated by a predetermined distance within the opening. A large transient electric voltage is formed between the wires using techniques well known to those skilled in the art, such as utilizing a piezoelectric crystal that can produce a substantial voltage when squeezed by mechanical means. The resulting large voltage causes the discharge of a spark between the pair of wires that Ignites the catalytic reaction media 164. And, as best illustrated in FIG. 14A through FIG. 14E, in order to ensure that the catalytic combustion process is confined to the catalytic combustion chamber 140, sealing members 168 and 170 are disposed within corresponding sealing channels 168A and 170A within the bottom chamber plate 126. with the sealing channel 168A concentrically positioned outside of bottom channel 126A and sealing channel 170A concentrically positioned inside of bottom channel 126A. In addition, a pair of O-rings 172 Is disposed around corresponding portions of flow-through fuel gas inlet elbow 150 and flow-through exhaust outlet elbow 152 in order to further seal the catalytic combustion chamber 140.
Once the catalytic reaction media 180 and combustion element 164 are positioned within the curved bottom channel 126A and the top chamber plate 124 is coupled to the bottom chamber plate 126, the catalytic reaction media 160 and the combustion element 164 are captured in a curved orientation within the curved sidewall section 142A of the elongate sidewall enclosure 142, thereby defining catalytic combustion chamber 140 as having the same shape as the elongate sidewall enclosure 142. In this regard, a curved elongate shape for the catalytic combustion chamber 140 is preferred in order to more evenly distribute the heat from the combustion chamber 140 to the top chamber plate 124 and, thereby, provide for a more even distribution of heat to the beverage or food within container 120. And, the most preferred curved elongate shape for the catalytic combustion chamber 140 is a curvature having a constant radius of curvature (hereinafter referred to as a “circular curvature”) providing a smooth and continuous surface within the combustion chamber 140. Although the catalytic combustion chamber 140 having a circular curvature is preferred, as described in connection with catalytic heating system 1, other curved shapes, such as serpentine or coiled, can be used with catalytic heating system 100
FIG. 15A and 15B more specifically illustrate the fuel supply assembly 130 mat is mounted on a topside of fuel supply platform 128. The fuel supply assembly 130 comprises the following fuel supply components a fuel inlet valve 131 having a compression fitting and tap for use in fluidly connecting the fuel assembly 130 to the fuel canister 132, containing dimethyl ether fuel gas 127; a liquid/gas separator 133, which could be, but not limited to, a porous oleophobic membrane such as “Supor R” made by Pall Corporation, having a tubular connection through tube 130A with the fuel inlet valve 131, with the liquid/gas separator 133 for removing any dimethyl ether fuel gas 127 that is in liquid form; a pressure regulator 134, such as an ultra-miniature regulator from the “PR-MLS” model series by Beswick Engineering, having a tubular connection through tube 130B with the liquid/gas separator 133, with the pressure regulator 134 for maintaining the pressure of the dimethyl ether fuel gas 127 at a predetermined level; a solenoid valve 135, such as the “LHL” series from the Lee Company, having a tubular connection through tube 130C with the pressure regulator 134, with the solenoid valve 135 for opening and closing the flow of dimethyl ether fuel gas 127 through the fuel supply assembly 130; a fuel and air mixing injector 136, such as a venturi injector, having a tubular connection through tube 130D with the solenoid valve 135, with the fuel and air mixing injector 136 for injecting the dimethyl ether fuel gas 127 and entrained air into the catalytic combustion chamber 140; and a temperature sensor 128A attached to the bottom surface of the bottom chamber plate 126 for sensing the temperature within the catalytic combustion chamber 140; and a temperature sensor 129B attached to the outside surface of the sidewall 121 of container 120 for sensing the temperature of the container 120. And, the fuel supply assembly 130 has a tubular connection to the catalytic combustion chamber 140 by inserting a top end of the fuel and air mixing injector 136 into the flow-through fuel gas inlet elbow 150 of the chamber 140.
The fuel supply assembly 130 further comprises the programmed microprocessor 166 that is attached to and in electrical connection to a circuit bord 137 that is mounted on the top side of the fuel supply platform 128. A battery 138, such as a lithium polymer type GM502030 from PowerStream Technology, Inc., can also be attached to and in electrical connection to the circuit board 137, or the battery 138 can be attached to any other appropriate location within the catalytic combustion assembly 122 or within the lower shell module 104 surrounding the catalytic combustion chamber 140. The battery 138 supplies electrical power to the programmed microprocessor 166 when the on/off button 112 is in the “on” position and disconnects electrical power when the on/off button 112 is in the off position. When activated, the programmed microprocessor 166, with inputs from the temperature sensors 129A and 129B, controls the functionality of the solenoid valve 135 in order to control the fuel gas flow rate and temperature within the enclosed catalytic combustion chamber 140. The activated programmed microprocessor 166 also supplies electrical power to the combustion starting element 164, which the microprocessor 166 coordinates with the supply of fuel gas to the enclosed catalytic combustion chamber 140 by opening and dosing the solenoid valve 135.
The cross-sectional side view presented in FIG. 16 illustrates that fuel canister 132 can contain the dimethyl ether fuel gas 127 and that the fuel canister 132 can be releasably connected to the fuel supply platform 128. In order to facilitate the connection, the fuel supply platform 128 also comprises a platform receptacle 178, integral with an underside of the fuel supply platform 128, that contains a platform receptacle opening 180 leading to a cylindrically shaped cavity 182, with the cavity 182 having: female threads extending distally from the opening 180; an inner O-ring 184 disposed within the cavity 182 and positioned distally from the female threads; and an outer O-ring 186 disposed around an outside surface of the platform receptacle 178. The fuel canister 132 contains a fuel flow valve 188. integral with the top of the fuel canister 132, and having male threads that can be used to connect the fuel canister 132 to the fuel supply platform 128 by screwing the fuel flow valve 188 into the platform receptacle 178. This action causes: 1) the tap within fuel gas compression fitting 131 to open the fuel flow valve 188, thereby allowing the dimethyl ether fuel gas 127, which has been compressed within the fuel canister 132, to flow from the canister 132 into the fuel supply assembly 130; and 2) an outside surface of the fuel canister 132 to engage the outer O-Ring 186 and the fuel flow valve 188 to engage the inner O-ring 184. thereby preventing dimethyl ether fuel gas 127 within the fuel container 132 from escaping to atmosphere.
FIG. 17A and 17B illustrate in more detail that the top of the shell lid 108 contains a flow opening 108A for allowing a beverage contained within the container 120 to flow out of the container 120 and into a flow guide 108B for channeling the flow of a beverage from the container 120. A shell slider valve 108C can be operated within a shell slider valve retainer 108D to open the shell slider valve 108C in order to allow the beverage to flow out of the container 120 or to close the shell slider valve 108C to prevent the beverage from flowing out of the container 120.
The catalytic heating system 100 has general industrial applicability in that it can be utilized to heat a container containing a beverage or food. Specifically, operation of the catalytic heating system 100 can proceed by providing a flow of the dimethyl ether fuel gas 127 by attaching the fuel canister 132, containing the dimethyl ether fuel gas 127 to the fuel supply platform 128, by screwing the fuel flow valve 188 into the platform receptacle 178, which causes the tap within the fuel gas compression fitting 131 to open the fuel flow valve 188 and causes the dimethyl ether fuel gas 127 within the fuel canister 132 to flow through compression fitting 131 and into the fuel supply assembly 130. The dimethyl ether fuel gas 127 will initially flow through the liquid/gas separator 133, where any fuel gas in liquid form will be removed, and then flow through the pressure regulator 134 that will maintain the fuel gas below a predetermined pressure, and continue flowing until it reaches the solenoid valve 135. With the on/off button 112 in the “off” position, the solenoid valve 135 will be closed, which prevents the dimethyl ether fuel gas 127 from flowing into the fuel and air mixing injector 136. Next, the catalytic heating system 100 can be operated to heat a beverage or food by, if necessary, removing the shell lid 108 by unscrewing it from its engagement with the top of the upper shell module 102. A beverage or food can then be placed into the container 120 and the shell lid 108 reattached to the upper shell module 102. The catalytic combustion process that is utilized to heat the beverage or food is initiated by depressing the on/off button 112 to the “on” position, which activates the programmed microprocessor 166 by closing the circuit connection between the battery 138 and programmed microprocessor 166. At a predetermined time after activation, the programmed microprocessor 166 causes the solenoid valve 135 to open, causing the dimethyl ether fuel gas 127 to flow into the fuel and air mixing injector 136. As the dimethyl ether fuel gas 127 flows through the fuel and air mixing injector 136, the velocity of the fuel gas flow 127 will increase due to the distal narrowing of the injector 136. Increasing the velocity of the dimethyl ether fuel gas 127 causes the pressure in the fuel and air mixing injector 136 to decrease, thereby entraining the dimethyl ether fuel gas 127 with atmospheric air in order to produce a dimethyl ether fuel gas and entrained air mixture, while maintaining an entrainment ratio of about 15 or more parts air to about one part dimethyl ether fuel gas 127 for the mixture. The dimethyl ether fuel gas and the entrained air mixture is injected by the fuel and air mixing injector 136 into the flow-through fuel gas inlet elbow 150 and then into the elongate sidewall enclosure 142 defining the catalytic combustion chamber 140, thereby constraining the flow of the mixture though the catalytic combustion chamber 140 to the curved and linear path best illustrated in FIG. 14E. While the flow of the dimethyl ether fuel gas and entrained air mixture is flowing through the catalytic combustion chamber 140, additional actions that contribute to the generation of the catalytic combustion process are: contacting the dimethyl ether fuel gas and entrained air mixture with the catalytic reaction media 160 and the combustion starting element 164: activating the programmed microprocessor 166 to cause an electrical current to be supplied to the combustion starting element 164, which causes the combustion starting element 164 to heat up, thereby igniting the flow of dimethyl ether fuel and entrained air mixture and generating the catalytic combustion process within the catalytic reaction media 160 within catalytic combustion chamber 140. The heat generated by the catalytic combustion process causes the top channel 124A and top chamber plate 124 to heat up by conducting heat away from the catalytic combustion chamber 140, which in turn heats the container 120 and the beverage or food within the container 120. Exhaust generated from the catalytic combustion process passes through the flow-through exhaust outlet elbow 152, through the tubular connection 153 between the outlet elbow 152 and the exhaust outlet duct 116 within the lower shell module 104, and out the exhaust outlet duct 116.
The advantages and unexpected results provided by the catalytic heating system 100 are the same as the advantages, and unexpected results of the catalytic heating system 1 described above. However, the catalytic heating system 100 has the additional advantage of being able to remove the upper shell module 102 and its attached container 120 within the upper shell module 102 from the lower shell module 104, providing the conveniences of using and washing the container 120 separate from the lower shell module 104.
In an another embodiment, a catalytic heating system 200 for heating a beverage or food with a stovetop surface 201 is described in FIG. 19A through FIG. 25. More specifically, FIG. 19A and FIG. 19B illustrate that the catalytic heating system 200, which is preferably portable, comprises: an outer shell 202 having a cylindrically shape; a canister base 210 adjacent to outer shell 202; an on/off button 204 on the outside surface of outer shell 202; a pair of air vents 206 for providing air passages to the inside of outer shell 202; a plurality of screws 208 for attaching the outer shell 202 to a catalytic combustion assembly 222 disposed within the outer shell 202, and an integrated chamber plate 225 having a cylindrically shape and having a stovetop surface 201 integral with the integrated chamber plate 225, with the integrated chamber plate 225 integral with the catalytic combustion assembly 222, and with the integrated chamber plate 225 concentrically disposed within a top opening 212 of outer shell 202. The components of catalytic combustion assembly 222 are described in detail below. And, FIG. 19B shows that the outer shell 202 contains an exhaust outlet duct 216 for providing an exhaust passage from the inside of the outer shell 202 to atmosphere.
FIG. 20 and FIG. 21 further illustrate the catalytic combustion assembly 222 disposed within and attached to the outer shell 202, with the catalytic combustion assembly 222 providing a catalytic heating source for the catalytic heating system 200. In this regard, the catalytic combustion assembly 222, as illustrated in more detail in FIG. 22 through FIG. 24, is identical to the catalytic combustion assembly 122 illustrated in FIG. 11 through FIG. 16 and described in connection with the catalytic heating system 100. And, although the identification numbers for the component parts of catalytic combustion assembly 222 as shown in the figures are different than the identification numbers for the component parts of catalytic combustion assembly 122, the corresponding components are identical For example, the integrated chamber plate 225, a fuel supply assembly 230, a fuel supply platform 228 and a fuel canister 232 within catalytic combustion assembly 222 are identical to integrated chamber plate 125, fuel supply assembly 130, fuel supply platform 128 and fuel canister 132, respectively, within catalytic combustion assembly 122.
The catalytic combustion assembly 222 can be used in a manner, which is the same as the manner of utilizing the catalytic combustion, assembly 122, to provide a catalytic heating process within the catalytic heating system 200. Specifically, the fuel canister 232 within catalytic combustion assembly 222, entrained air mixture within the enclosed catalytic combustion chamber 240 generates a catalytic combustion process within the catalytic reaction media 260 disposed within the catalytic combustion chamber 240. The heat generated from the catalytic combustion process heats the top chamber plate 224 within the integrated chamber plate 225, just like the catalytic heating system 100 uses the heat generated from the catalytic combustion chamber 140 to heat the top chamber plate 124 within the Integrated chamber plate 125. In this regard, however, the manner in which the two systems are used to heat a container are different. In the catalytic heating system 100, the heated top chamber plate 124 is brought into adjacent contact with the bottom of container 120 by attaching the top module 102 to the bottom module 104, thereby providing for conduction of heat directly from the heated top chamber plate 124 to the container 120. By contrast, in catalytic heating system 200, the heated top chamber plate 224 within integrated chamber plate 225 is utilized as the stovetop surface 201 that can be used to heat a container, like a pot, pan or similar container that can be used to heat its contents by simply placing the container on the stovetop surface 201. FIG. 25 illustrates a pot (in dashed lines) that has been placed on the stovetop surface 201. The container is heated by the conduction of heat directly from the stovetop surface 201 to the container. A more specific description of all of the component parts of the catalytic combustion assembly 222 and the manner in which those component parts operate to generate conductive heat is presented above in connection with the description of the component parts of catalytic combustion assembly 122, which is equally applicable to catalytic combustion assembly 222. Further, the advantages of the catalytic combustion assembly 122 are also equally applicable to the catalytic combustion assembly 222.
in an another embodiment, a catalytic heating system 300 for heating a beverage or food, with a stovetop surface 301 is described in FIG. 26 through FIG. 32. More specifically, FIG. 26 illustrates that the catalytic heating system 300, which is preferably portable, comprises: an outer shell 302 having a cylindrically shape; a canister base 310 adjacent to outer shell 302; an on/off button 304 on the outside surface of outer shell 302, a pair of air vents 306 for providing air passages to the inside of outer shell 302; a plurality of screws 308 for attaching the outer shell 302 to a catalytic combustion assembly 322 disposed within the outer shell 302; and an integrated chamber plate 325 having a cylindrically shape and having the stovetop surface 301 integral with the integrated chamber plate 325, and with the integrated chamber plate 325 integral with the catalytic combustion assembly 322. The cylindrically shaped integrated chamber plate 325 is concentrically positioned above the cylindrically shaped outer shell 302 and adjacent to a top end of the outer shell 302, as shown in FIG. 27 and FIG. 28, with the cylindrically shaped integrated chamber plate 325 having a circumference that is greater than the circumference of the outer shell 302, such that an integrated chamber plate perimeter wall 351 of the integrated chamber plate 325 extends away from the outside perimeter of the outer shell. The components of the catalytic combustion assembly 322 are described more specifically below,
The components of the catalytic combustion assembly 322 are illustrated in more detail in FIG. 27 through FIG. 31. The figures illustrate that the catalytic combustion assembly 322 comprises: a top chamber plate 324; a bottom chamber plate 326 coupled to the top chamber plate 324, thereby forming the cylindrically shaped integrated chamber plate 325, with integrated chamber plate 325 having the stovetop surface 301 integral with top chamber plate 324; a fuel supply platform 328; a fuel supply assembly 330 having tubular connections to the fuel supply platform 328 and to the bottom chamber plate 326; a fuel canister 332, with the canister base 310 attached to a bottom of the fuel canister 332, and with the fuel canister 332 removably attached to the fuel supply platform 328; and a fuel gas 327, preferably dimethyl ether, in a state of compression within the fuel canister 332. Dimethyl ether is the preferred fuel gas due. in part, to having a stoichiometric air to fuel ratio mat is conducive to obtaining complete combustion of the fuel gas in a catalytic combustion process. Other fuel gasses, however, like butane, propane and mixtures of those fuel gasses, along with mixtures of dimethyl ether, butane and propane, can also be used as the fuel gas 327. As mentioned above, a reference to a “fuel” or a “fuel gas” means fuel in a gaseous phase, unless indicated otherwise.
The perspective and exploded view of FIG. 29A and top plan view of FIG. 29B illustrate the integrated chamber plate 325 separated from the tubular connection of the bottom chamber plate 326 to the fuel supply assembly 330, and shows that the integrated chamber plate 325 is formed by coupling the top chamber plated 324 to the bottom chamber plate 326. The integrated chamber plate 325 has integrated chamber plate top and bottom sides 350 and 352, with the integrated chamber plate top side 350 coextensive with the stovetop surface 301, and with the integrated chamber plate perimeter wall 351 of Integrated chamber plate 325 disposed between and integral with the integrated chamber plate top and bottom sides 350 and 352. The top chamber plate 324 of integrated chamber plate 325 has a cylindrically shape and top and bottom chamber plate sides 324A and 324B, respectively. The bottom chamber plate 326 of integrated chamber plate 326 also has a cylindrically shape, with the bottom chamber plate 326 having top and bottom sides 326A and 326B, respectively, and a perimeter wall 326C disposed between and integral with the top and bottom sides 326A and 326B. A flow-through fuel gas inlet 356 is integral with the center of the bottom chamber plate 326. When the top chamber plate and bottom chamber plates 324 and 326 are coupled together to form integrated chamber plate 325, the top side 324A of top chamber plate 324 is coextensive with the integrated chamber plate top side 350 and the stovetop surface 301, the bottom side 326B of bottom chamber plate 326 is coextensive with integrated chamber plate bottom side 352, and the perimeter wall 326C of bottom chamber plate 326 is coextensive with the integrated chamber plate perimeter wall 351. A plurality of channels 362, preferably six in number, are integral with the top side 326A of bottom chamber plate 328, with a proximal end each channel out of the plurality of channels 362 integral with and fluidly connected to the flow-through fuel gas inlet 356 and with an opposite distal end of each channel out of the plurality of channels 362 integral with a corresponding exhaust outlet out of a plurality of exhaust outlets 358 within the chamber plate perimeter wall 326C of the bottom chamber plate 326. Preferably, the inside surface of each of the channels out of the plurality of channels 362 has an elongate curved shape, with a bottom flat surface 363 of each channel being integral with and perpendicular to a pair of opposing sidewalk 365. And, when the top chamber plate 324 is coupled to the bottom chamber plate 326, the plurality of channels 382 and top chamber plate 324 form a corresponding plurality of enclosed catalytic combustion chambers 360, with each enclosed catalytic combustion chamber out of the plurality of enclosed catalytic combustion chambers 360 preferably having a curved shape with four inside elongate sidewall surfaces, with each elongate sidewall surface perpendicular or normal to an adjacent sidewall surface and with each sidewall surface opposite from a sidewall surface. It is preferred that the distance between opposite sidewall surfaces be about 10 millimeters or less or more preferably between about 5 and 10 millimeters. These dimensions provide the advantage of limiting or preventing flame propagation in the catalytic combustion chamber. Each enclosed catalytic combustion chamber out of the plurality of catalytic combustion chambers 360 also has a single flow-through fuel gas inlet opening 356A, having a flow-through connection with the flow through fuel gas inlet 356, and a single flow-through exhaust outlet opening 358A, having a flow-through connection with an exhaust outlet 358, with each enclosed catalytic combustion chamber 360 not having any other flow-through openings accessing the enclosed catalytic combustion chamber 360. A catalytic reaction media 364 is disposed within each enclosed catalytic combustion chamber out of the plurality of enclosed catalytic combustion chambers 360, with the catalytic reaction media 364 conforming to the shape of the enclosed catalytic combustion chamber and extending a predetermined distance within the chamber. If the catalytic combustion chamber is curved as in FIG. 29A and FIG. 29B, the catalytic reaction media 364 will conform to the same curved shape having an outside convex portion 364A and an inside concave portion 364B.
The bottom side 328B of bottom chamber plate 326, as show In FIG. 29C, contains a plurality of cavities 368 that correspond in number to the plurality of enclosed catalytic combustion chambers 360 integral with the top side 326A of bottom chamber plate 326. Each of the cavities out of the plurality of cavities 368 is positioned such that the cavity does not extend into an adjacent enclosed catalytic combustion chamber out of the plurality of enclosed catalytic combustion chambers 360. A fuel gas tubular connector 370 is coupled at one open end to the bottom side 326B of the bottom chamber plate 326, with said open end surrounding the flow-through fuel gas inlet 356, and with an opposite open end of fuel gas tubular connector 370 that can be fluidly connected to a fuel and air mixing injector 336 within fuel supply assembly 330. A combustion starting element 374, preferably a pair of wires that are part of a spark ignition system, are passed through an opening in the side of fuel gas tubular connector 370 so that the combustion starting element 374 can be positioned inside the open space within the fuel gas tubular connector 370. A microprocessor 366 within fuel supply assembly 330 is utilized to control the spark ignition system which generates an electrical spark between the pair of wires forming the combustion starting element 374. And, a temperature sensor 376 can be integral with me bottom side 326B of bottom chamber plate 326 for sensing the temperature of the catalytic combustion process.
FIG. 30A, FIG. 30B and FIG. 31 illustrate in more detail the fuel supply assembly 330, fuel supply platform 328 and fuel canister 332 within catalytic combustion assembly 322. With one exception, these components within catalytic combustion assembly 322 are identical to the fuel supply assemblies 130 and 230, fuel supply platforms 128 and 228 and fuel canisters 132 and 232 illustrated and described in connection with the catalytic heating systems 100 and 200. And, although the identification numbers for the component parts of fuel supply assembly 330, fuel supply platform 328 and fuel canister 332 as shown in the figures are different than the identification numbers for the component parts of: fuel supply assembly 130, fuel supply platform 128, and fuel canister 132 shown in FIG. 15A, FIG. 15B and FIG. 16; and fuel supply assembly 230, fuel supply platform 228, and fuel canister 232 shown in FIG. 23A, FIG. 23B and FIG. 24, the corresponding parts component parts are identical. The only component part of fuel supply assembly 330 that is not disclosed in fuel supply assembly 130 or 230 is a fuel gas inlet tubular extension 330E fluidly connected at one end to the fuel and air mixing injector 336 and can be fluidly connected at the other end to fuel gas tubular connector 370 integral with the bottom chamber plate 326 integral with integrated chamber plate 325.
The catalytic combustion assembly 322 within catalytic heating system 300 can be used in a manner, which is the same as the manner of utilizing the catalytic combustion assembly 222 within catalytic heating system 200, in order to generate a fuel gas and entrained air mixture to be injected into a combustion chamber Specifically, the fuel canister 332 within catalytic combustion assembly 322, which is releasably connected to the fuel supply assembly 330, supplies fuel gas to the fuel supply assembly 330, which in turn utilizes the fuel and air mixing injector 336 to generate the fuel gas and entrained air mixture There are differences, however, in the manner in which catalytic combustion assembly 322, as compared to catalytic combustion assembly 222, utilizes the fuel gas and entrained air mixture to generate conductive heat from a catalytic combustion process. The catalytic combustion assembly 322 within catalytic heating system 300 uses the fuel and air mixing injector 336 to inject the fuel gas and entrained air mixture through fuel gas tubular connector 370 into the plurality of enclosed catalytic combustion chambers 360, where catalytic combustion processes heat the top chamber plate 324 and stovetop surface 301. By comparison, catalytic combustion assembly 222 within heating system 200, uses fuel and air mixing injector 236 to inject the fuel gas and entrained air mixture through flow-through fuel gas inlet 150 into a single enclosed catalytic combustion chamber 240, where a catalytic combustion process heats the top chamber plate 224 and stovetop surface 201. The plurality of enclosed catalytic combustion chambers 360 is provided, in part, due to the need to generate sufficient heat to heat the stovetop surface 301 which has a larger surface area as compared to the surface area of stovetop surface 201 within catalytic heating system 200. And, the catalytic combustion assembly 322 uses the plurality of exhaust outlets 358 within the chamber plate perimeter wall 326C of the bottom chamber plate 326 to direct exhaust from the plurality of enclosed catalytic combustion chambers 360 to atmosphere, while catalytic combustion assembly 222 within catalytic heating system 200 utilizes a single exhaust outlet 1420 integral with the bottom chamber plate 228 in order to direct exhaust to atmosphere through exhaust outlet duct 216 within outer shell 202. Further, catalytic combustion assembly 322 preferably uses the combustion starting element 374 within the spark ignition system to ignite the fuel gas and entrained air mixture coming from the fuel supply assembly 330 before the mixture reaches the plurality of catalytic reaction media 364, while the catalytic combustion assembly 222 preferably uses a coiled combustion starting element 264C that is embedded in the catalytic reaction media 260 to ignite the fuel gas and entrained air mixture. With the exception of these differences, the description of the use of catalytic combustion assembly 222 within catalytic heating system 200 to generate a catalytic heating process to conductively heat a container, like a pot, pan or similar container by simply placing the container on the stovetop surface 201 as shown in FIG. 32, is equally applicable to the use of the catalytic combustion assembly 322 within catalytic heating system 300.
Although each enclosed catalytic combustion chamber out of the plurality of enclosed catalytic combustion chambers 360 has a preferred elongate curved shape, other shapes can be utilized. For example, the catalytic combustion chamber can be linear or have a combination of linear and a curved sections. In this regard, however, the preferred elongate curved shape of each of the enclosed combustion chambers out of the plurality of enclosed combustion chambers 360 substantially increases the amount of heat energy that the catalytic combustion process within the enclosed catalytic combustion chamber can transfer to the top chamber plate 324 and its integral stovetop surface 301. As the ignited fuel gas and entrained air mixture reacts with the catalytic reaction media 364 disposed with the catalytic combustion chamber and flows through the chamber, centrifugal force generates an asymmetric laminar flow velocity, causing higher temperatures, causing the majority of the heat energy generated from the catalytic combustion process to be produced in a zone much closer to the sidewall surface of the catalytic combustion chamber that is adjacent to the outside convex portion of the catalytic reaction media than would otherwise occur. This action, in turn, causes a more efferent transfer of heat energy to the integrated chamber plate and its integral stovetop surface. In addition, the heat transferred from the catalytic combustion chamber to the top chamber plate can be more uniformly distributed across the top chamber plate by utilizing a material, such as Annealed Pyrolytic Graphite, which has the characteristic of conducting heat preferentially in the plane of the top chamber plate, rather than equally well in all directions, as is more common. By comparison, a similar catalytic combustion process generated in an enclosed combustion chamber having an elongate linear shape would not accelerate the flow of fuel gas and entrained air mixture through the chamber and, as a result, additional heat energy would not be generated.
Another embodiment of the integrated chamber plate 325 within the catalytic combustion assembly 322 is illustrated in FIG. 29D. In this embodiment each of the enclosed catalytic combustion chambers out of the plurality of enclosed catalytic combustion chambers 360, which are formed by coupling the top chamber plate 324 to bottom chamber plate 326, has an elongate linear shape, rather than an elongate curved shape. Otherwise, and with one additional feature, the component parts of the integrated chamber plate 325 are identical for both embodiments The additional feature, as illustrated in the figures, is a flow diverter 367 having a semispherically shape, with the flow diverter 367 integral with the bottom side 324B of top chamber plate 324 and positioned at the center of the bottom side 324B. The flow diverter 367 is provided in order to increase the amount of heat energy that can be transferred from the enclosed catalytic combustion chamber 360 to the stovetop surface 301. After the fuel gas and entrained air mixture has been ignited by the combustion starting element 374 within the spark ignition system, the ignited flow contacts the flow diverter 367 causing the flow to separate into a planar flow adjacent to and in contact with the bottom side 324B of top chamber plate 32, with the planar flow forming a generally uniform radial pattern as it expands, remaining adjacent to and in contact with the bottom side 324B of top chamber plate 324. Ultimately, the planar flow separates into a corresponding plurality of separate planar flows that correspond to the plurality of the enclosed catalytic combustion chambers 360. As each separate planar flow enters a corresponding catalytic combustion chamber, the flow remains adjacent to and contact with that portion of the bottom side plate 324B of top chamber plate 324 that forms a top inside sidewall out of me four inside sidewall surfaces within the catalytic combustion chamber, and remains adjacent to and in contact with the top inside sidewall for a significant distance. As a result of this flow pattern inside the enclosed catalytic combustion chamber 360, a substantial portion of the heat energy generated inside the catalytic combustion chamber is generated in a narrow zone within the catalytic reaction media 364 located near the top sidewall surface of the catalytic combustion chamber, which in turn transfers more heat energy to the stovetop surface 301. Without the utilization of the flow diverter 367, more of the heat generated in the enclosed catalytic combustion chamber 360 would exit the chamber as exhaust.
In an another embodiment, a catalytic heating system 400 for heating a beverage or food, with a stovetop surface 401 is described in FIG. 33 through FIG. 38. More specifically. FIG. 33 illustrates that the catalytic heating system 400, which is preferably portable, comprises: an outer shell 402 having a cylindrically shape; a canister base 410 adjacent to outer shell 402; an on/off button 404 on the outside surface of outer shell 402; a pair of air vents 406 for providing air passages to the inside of outer shell 402; a plurality of screws 408 for attaching me outer shell 402 to a catalytic combustion assembly 422 disposed within the outer shell 402; and an integrated chamber plate enclosure having a cylindrically shape and having the stovetop surface 401 integral with the integrated chamber plater enclosure 425, and with the integrated chamber plate enclosure 425 integral with the catalytic combustion assembly 422. The cylindrically shaped Integrated chamber plate enclosure 425 is concentrically positioned above the cylindrically shaped outer shell 402 and adjacent to a top end of the outer shell 402, as shown in FIG. 34 and FIG. 35, and with the integrated chamber plate enclosure 425 having a circumference that is greater than the circumference of the outer shell 402, such that an integrated chamber plate perimeter wall 451 of the integrated chamber plate enclosure 425 extends away from the outside perimeter of the outer shell. The components of the catalytic combustion assembly 422 are described more specifically below.
The components of the catalytic combustion assembly 422 are illustrated in more detail in FIG. 34 through FIG. 38. The figures illustrate that the catalytic combustion assembly 422 comprises: a top chamber plate 424: a bottom chamber plate 426 coupled to the top chamber plate 424, thereby forming the integrated chamber plate enclosure 425, a fuel supply platform 428; a fuel supply assembly 430 having tubular connections to the fuel supply platform 428 and to the bottom chamber plate 426; a fuel canister 432, with the canister base 410 attached to a bottom of the fuel canister 432, and with the fuel canister 432 removably attached to the fuel supply platform 428; and dimethyl ether fuel gas 427 as the preferred fuel gas contained in a state of compression within the fuel canister 432. Dimethyl ether is the preferred fuel gas due, in part, to having a stoichiometric air to fuel ratio that is conducive to obtaining complete combustion of the fuel gas in a catalytic combustion process. Other fuel gasses, however, like butane, propane and mixtures of those fuel gasses along with mixtures of dimethyl ether, butane and propane, can also be used as the fuel gas 427. As mentioned above, a reference to a “fuel” or a “fuel gas”means fuel in a gaseous phase, unless indicated otherwise.
The perspective and exploded view of FIG. 36A and top plan view of FIG. 36B illustrate integrated chamber plate enclosure 425 separated from the tubular connection of the bottom chamber plate 428 to the fuel supply assembly 430 and shows that the integrated chamber plate enclosure 425 is formed by coupling the top chamber plate 424 to the bottom chamber plate 326. The integrated chamber plate enclosure 425 has an integrated chamber plate top and bottom sides 450 and 452, with the integrated chamber plate top side coextensive with the stovetop surface 401, and with the integrated chamber plate perimeter wall 451 disposed between and integral with the integrated chamber plate top and bottom sides 450 and 452. The top chamber plate 424 has a flat cylindrically shape and top and bottom and the bottom chamber plate 426 has a cylindrically shape with a perimeter wall 442, a closed bottom end 448 and open top end 449, and with a flow-through fuel gas inlet 440 through the center of closed bottom end 448 of the bottom chamber plate 426 and a plurality of exhaust outlets 458 through perimeter wall 442. The integrated chamber plate enclosure 425 is formed by coupling the top chamber plate 424 to the bottom chamber plate 426, thereby creating an open space with the integrated chamber plate enclosure 426. When the top chamber plate and bottom chamber plates 424 and 426 are coupled together to form integrated chamber plate enclosure 425, the bottom end 448 of bottom chamber plate 426 is coextensive with integrated chamber plate bottom side 452, and the perimeter wall 442 of bottom chamber plate 426 is coextensive with the integrated chamber plate perimeter wall 451. A guide vane 454 ring, having a plurality of guide vane ring openings 454A through the guide vane ring 454, is disposed within the open space within integrated chamber plate enclosure 425 and is integral with the inside surface of the closed bottom end 448 of bottom chamber plate 426 and positioned inside of and concentric with the perimeter wall 442 of bottom chamber plate 426. A plurality of guide vane ring flaps 456 are integral with the guide vane 454 ring, with each guide vane flap out of the plurality of guide vane ring flaps 456 integral at one end with an outside surface of the guide vane 454 ring, and with the opposite end of the guide vane flap extending away and at an angle from a corresponding ring opening out of the plurality of guide vane ring openings 454A. A catalytic reaction media 462, having a cylindrical ring shape with an inside concave surface 462A, an outside convex surface 462B, and a uniform radial dimension, is also disposed within the open space within integrated chamber plate enclosure 425 and is in contact with the inside surface of the closed bottom end 448 of bottom chamber plate 428 and further positioned between the perimeter wall 442 of the bottom chamber plate 426 and the guide vane 454 ring. The catalytic reaction media 462 has a height such that when the top and bottom chamber plates, 424 and 426, are coupled together the catalytic reaction media 462 is also in contact with the top chamber plate 424, thereby enclosing the catalytic reaction media 462 between and in contact with the top and bottom chamber plates 424 and 426, and defining a catalytic combustion chamber 460 in the space between the top and bottom chamber plates 424 and 426 and between the perimeter wall 442 of the bottom chamber plate 426 and the guide vane ring 454. The figure also shows the catalytic reaction media 462 with a segment of its cylindrical ring shape removed in order to illustrate a combustion starting element 464 that is disposed within the catalytic reaction media 462, with the combustion starting element 464 having a coiled shape and connected to a pair of electrically conductive terminals 465, as part of an ignition system, extending through the closed bottom end 448 of bottom chamber plate 426 as shown in FIG. 36C illustrating the bottom side of integrated chamber plate enclosure 425. A plurality of curved guide vanes 470, preferably six in number, are also integral with the inside surface of closed bottom end 448 of bottom chamber plate 426, with the plurality of curved guide vanes 470 positioned so as to form a fan-like structure. And, a proximal end of each guide vane out of the plurality of curved guide vanes 470 is adjacent to the flow-through fuel gas inlet 440, and a distal end of each guide vane is integral with an inside surface of guide vane 454 ring and positioned such that a ring opening out of the plurality of guide vane ring openings 454A is between adjacent distal ends of a guide vane.
The bottom chamber plate 426, as illustrated in FIG. 36C, also contains a fuel gas tubular connector 472 coupled at one open end to the outside surface of closed bottom end 448 of the bottom chamber plate 426, with said open end of fuel gas connector 472 surrounding the flow-through fuel gas inlet 440, and with an opposite open end of fuel gas tubular connector 472 that can be fluidly connected to an fuel and air mixing injector 436 within fuel supply assembly 430.
FIG. 37A, FIG. 37B and FIG. 38 illustrate in more detail the fuel supply assembly 430, fuel supply platform 428 and fuel canister 432 within catalytic combustion assembly 422. With one exception, these components within catalytic combustion assembly 422 are identical to the fuel supply assemblies 130 and 230, fuel supply platforms 128 and 228 and fuel canisters 132 and 232 illustrated and described In connection with the catalytic heating systems 100 and 200. And, although the Identification numbers for the component parts of fuel supply assembly 430, fuel supply platform 428 and fuel canister 432 as shown in the figures are different than the identification numbers for the component parts of: fuel supply assembly 130, fuel supply platform 128, and fuel canister 132 shown in FIG. 15A, FIG. 15B and FIG. 16; and fuel supply assembly 230, fuel supply platform 228: and fuel canister 232 shown in FIG. 23A, FIG. 23B and FIG. 29, the corresponding parts component parts are identical. The only component part of fuel supply assembly 430 that is not disclosed in fuel supply assembly 130 or 230 is a fuel gas inlet tubular extension 430E fluidly connected at one end to the fuel and air mixing injector 436 and can be fluidly connected at the other end to fuel gas tubular connector 472 integral with the bottom chamber plate 426 integral with integrated chamber plate enclosure 425.
The catalytic combustion assembly 422 within catalytic heating system 400 can be used in a manner, which is the same as the manner of utilizing the catalytic combustion assemblies 222 and 322 within catalytic heating systems 200 and 300, respectively, to generate a fuel gas and entrained air mixture to be injected into a combustion chamber Specifically, the fuel canister 432 within catalytic combustion assembly 422, which Is releasably connected to the fuel supply assembly 430, supplies fuel gas to the fuel supply assembly 430, which in turn utilizes the fuel and air mixing injector 436 to generate the fuel gas and entrained air mixture. However, the manner in which the catalytic heating system 400 utilizes the fuel gas and entrained air mixture to generate conductive heat from a catalytic combustion process has several significant differences from the other two systems. In the catalytic heating system 400, the injected fuel gas and entrained air mixture is injected through the flow-through fuel gas inlet 440 within the center of bottom chamber plate 426, just like in system 300 where the fuel and a if mixture is injected through flow-through fuel gas inlet 356 within the center of bottom chamber plate 326, but before the fuel gas and entrained air mixture reaches the catalytic reaction media 462, the mixture flows through the plurality of curved guide vanes 470. This action causes the fuel gas and entrained air mixture to divide into a corresponding plurality of curved fluid flows and for the curved fluid flows to accelerate The plurality of curved fluid flows then pass through a corresponding plurality of guide vane ring openings 454A through the guide vane 454 ring. And, as the plurality of curved fluid flows exit the corresponding plurality guide vane ring openings 454A, a corresponding plurality of guide vane ring flaps 456 further accelerate the curved fluid flows, thereby creating a circulating flow field concentration fuel gas and entrained air mixture within the catalytic reaction media 462 and generally adjacent to inside concave surface 462A of the catalytic reaction media 462. More specifically, the circulating flow field has both a velocity distribution and a fuel gas and entrained air mixture concentration distribution that is more spatially uniform within in the catalytic reaction media 462 than would otherwise occur without the circulating flow field. At a predetermined time after the formation of the circulating concentration of the fuel gas and entrained air mixture, the microprocessor 466 activates the ignition system, causing combustion starting element 464 to generate heat and ultimately ignite the fuel gas and entrained air mixture that has started circulating inside the catalytic reaction media 462. Because of the circular flow, the ignition process proceeds in a circular pattern around the catalytic reaction media until all of the reaction media is contributing to the catalytic heat production. The heat generated from the catalytic combustion process will be distributed over a greater reaction zone volume within the catalytic reaction media 462, similarly contributing to a more uniform distribution of heat energy across the integrated chamber plate 425 and its integral stovetop surface 401, as well as inhibiting the heat generation reaction zone in the catalytic reaction media 462 from collapsing toward the flow-through fuel gas inlet 440. As the catalytic combustion process proceeds within catalytic combustion chamber 460, heat is transferred to the top chamber plate 424 and to stovetop surface 401, which can be used to heat a container, like a pot, pan or similar container that can be used to heat its contents by simply placing the container on the stovetop surface 401. Exhaust passes through the outside convex surface 4628 of the catalytic reaction media 462 and ultimately passes through the plurality of exhaust outlets 458 through perimeter wall 442 of bottom chamber plate 426 and then to atmosphere. A microprocessor 366 within fuel supply assembly 330 is utilized to control the spark ignition system which generates an electrical spark between the pair of wires forming the combustion starting element 374. And, a temperature sensor 476 can be integral with the bottom side 426B of bottom chamber plate 426 for sensing the temperature of the catalytic combustion process.
The catalytic heating systems described herein embody novel and thermodynamically significant features that are not present in other portable catalytic heating systems. One such feature is that the stovetop heating surface is integral with the integrated chamber plate that contains the enclosed catalytic combustion chamber. As a result heat from the catalytic combustion process within the catalytic combustion chamber is transferred by thermal conduction through the integrated chamber plate to its integral stovetop surface. Similarly, when a container placed on the stovetop surface, heat is transferred from the stovetop surface by thermal conduction to the bottom of the container that is in contact with the stovetop surface Another feature that is provided for in catalytic heating systems 200 and 300 is that the elongate and enclosed catalytic combustion chamber has a single fuel gas opening and a single exhaust opening, with both openings fluidly connected to the catalytic combustion chamber. As a result, almost all of the heat from the catalytic combustion process within the catalytic combustion chamber is transferred to the integrated chamber plate, rather than having a substantial amount of the heat exit the chamber as exhaust. This feature significantly enhances the efficiency of the systems in heating the stovetop surface. Another feature that is characteristic of catalytic heating systems 200 and 300 is that when dimethyl ether is utilized as the preferred fuel gas, the efficiency of the system is further enhanced due to the fact that dimethyl ether, as compared to other fuel gases, has a relatively low stoichiometric air to fuel ratio which provides for the complete combustion of the fuel gas and entrained air mixture within the catalytic combustion chamber. This complete combustion also has an added safety feature in that no uncombusted fuel gas is discharged to atmosphere, where the fuel gas could contaminate the air, further, the preferred shape of the catalytic combustion chamber within in catalytic heating systems 200 and 300 is curved, which further enhances the heating efficiency of the system. As the ignited fuel gas and entrained air mixture reacts with the catalytic reaction media disposed with the catalytic combustion chamber and flows through the chamber, centrifugal force generates an asymmetric laminar flow velocity, causing higher temperatures to be generated from the catalytic combustion process at the outside convex portion of catalytic reaction media. These higher temperatures, in turn, cause a concentration of heat to be transferred to integrated chamber plate and its integral stovetop surface.
In alternate embodiment of the catalytic heating system 300, each of the plurality of catalytic combustion chambers within the integrated chamber plate can have a linear shape, rather than a curved shape. In this embodiment, the flow of the ignited fuel gas and entrained air mixture through the catalytic combustion chambers would not accelerate causing an increase in the concentration of the ignited fuel gas and entrained air mixture in the chamber. However, a comparable effect can be implemented by using the flow diverter attached to the bottom surface of the top chamber plate. As describe in detail above the flow diverter causes the flow of ignited fuel gas and entrained air mixture to remain adjacent to and in contact with to the bottom surface of the top chamber plate, resulting in an increase in the concentration of the ignited fuel gas and entrained air mixture between the catalytic reaction media and the top chamber plate, which gives rise to a concentration of higher temperatures In the catalytic combustion chamber that conductively heats the top chamber plate and its integral stovetop surface.
The catalytic ideating systems described herein embody novel and thermodynamically significant features that are not present in other portable catalytic heating systems. One such feature is that the stovetop heating surface is integral with the integrated chamber plate that contains the enclosed catalytic combustion chamber. As a result heat from the catalytic combustion process within the catalytic combustion chamber is transferred primarily by thermal conduction through the integrated chamber plate to Its integral stovetop surface. Similarly, when a container placed on the stovetop surface, heat is transferred from the stovetop surface by thermal conduction to the bottom of the container that is in contact with the stovetop surface. Another feature that is provided for in catalytic heating systems 200 and 300 is that the elongate and enclosed catalytic combustion chamber has a single fuel gas opening and a single exhaust opening, with both openings fluidly connected to the catalytic combustion chamber. As a result, almost all of the heat from the catalytic combustion process within the catalytic combustion chamber is transferred to the integrated chamber plate, rather than having a substantial amount of the heat exit the chamber as exhaust. This feature significantly enhances the efficiency of the systems in heating the stovetop surface.
Another feature that is characteristic of catalytic heating systems 200 and 300 is that when dimethyl ether is utilized as the preferred fuel gas, the efficiency of the system is further enhanced due to the fact that dimethyl ether, as compared to other fuel gases, has a relatively low stoichiometric air to fuel ratio which provides for the complete combustion of the fuel gas and entrained air mixture within the catalytic combustion chamber. This complete combustion also has an added safety feature in that no uncombusted fuel gas is discharged to atmosphere, where the fuel gas could contaminate the air. Further, the preferred shape of the catalytic combustion chamber within in catalytic heating systems 200 and 300 is curved, which further enhances the heating efficiency of fee system. As the ignited fuel gas and entrained air mixture reacts with the catalytic reaction media disposed with the catalytic combustion chamber and flows through the chamber, centrifugal force generates an asymmetric laminar flow velocity, causing the majority of the heat energy generated from the catalytic combustion process, to be produced in a zone much closer to the sidewall surface of the catalytic combustion chamber that is adjacent to the outside convex portion of the catalytic reaction media than would otherwise occur. This action, in turn, causes a more efficient transfer of heat energy to the integrated chamber plate and its integral stovetop surface.
Although catalytic heating system 400 does not provide for an elongate and enclosed catalytic combustion chamber as in systems 200 and 300, the catalytic heating system 400 does contain novel integrated chamber plate components that provide for enhanced efficiency in heating the stovetop surface. As discussed in more detail above, the fan-like structure and its related components creates a concentrated flow of circulating fuel gas and entrained air mixture as the flow enters the inside concave surface of the catalytic reaction media. This results in a circulating flow field with both a velocity distribution and a fuel gas and entrained air mixture concentration distribution that is more spatially uniform within the catalytic reaction media than would otherwise occur. In turn, the heat generated from the catalytic combustion process will be distributed over a greater reaction zone volume of the catalytic media, similarly contributing to a more uniform distribution of heat energy across the integrated chamber plate and its integral stove top, as well as, inhibiting the heat generating reaction zone in the catalytic media from collapsing toward the flow-through fuel gas inlet.
The catalytic heating systems described herein have general industrial applicability in that they can be utilized to heat a container containing a beverage or food using a stovetop surface.
Although a preferred embodiment and other embodiments have been described, It will be recognized by those skilled in the art that other embodiments and features can be provided without departing from the underlying principles of those embodiments. The scope of the invention is defined by the appended claims.

Claims

1. A catalytic combustion assembly for heating a stovetop surface, comprising:

a chamber plate having chamber plate top and bottom sides, with a chamber plate perimeter wall disposed between and integral with the chamber plate top and bottom sides, and with the stovetop surface integral with the chamber plate top side;

a flow-through fuel gas inlet and a flow-through exhaust outlet integral with the chamber plate bottom side;

an enclosed catalytic combustion chamber integral with the chamber plate, with the enclosed catalytic combustion chamber having at one end a combustion chamber fuel gas opening fluidly connected to the flow-through fuel gas inlet and at another end a combustion chamber exhaust opening fluidly connected to the flow-through exhaust outlet, and with no other openings providing access to the enclosed catalytic combustion chamber;

a catalytic reaction media disposed within the enclosed catalytic combustion chamber;

a combustion starting element disposed within the catalytic reaction media;

a fuel supply assembly mounted on a fuel supply platform, with the fuel supply assembly having a fuel and air mixing injector fluidly connected to the flow-through fuel gas inlet;

a fuel canister sealably connected to the fuel supply platform for supplying a fuel gas to the fuel supply assembly; and

whereby the fuel and air mixing injector within the catalytic combustion assembly can entrain the fuel gas with air and inject a fuel gas and entrained air mixture through the flow-through fuel gas Inlet and into the enclosed catalytic combustion chamber, where the combustion starting element can ignite the fuel gas and entrained air mixture and the catalytic reaction media can generate a catalytic combustion process within the enclosed catalytic combustion chamber, with exhaust from the catalytic combustion process flowing through the flow-through exhaust outlet to atmosphere, with the catalytic combustion process transferring heat to the chamber plate top side and integral stovetop surface, and with the stovetop surface for conductively transferring heat to a container.

2. The catalytic combustion assembly of claim 1 in which the fuel gas is selected from the group consisting of dimethyl ether, butane, propane and mixtures thereof.

3. The catalytic combustion assembly of claim 1 in which the fuel gas has a stoichiometric air to fuel ratio of about 15.

4. The catalytic combustion assembly of claim 1 in which the catalytic reaction media comprises a substrate, combined with a catalyst support and an active catalyst.

5. The catalytic combustion assembly of claim 1 in which the catalytic combustion chamber has an elongate cylindrically shape.

6. The catalytic combustion assembly of claim 1 in which the enclosed catalytic combustion chamber has a curved shape.

7. The catalytic combustion assembly of claim 8 in which the curved shape of the enclosed catalytic combustion chamber has a circular curvature.

8. The catalytic heating assembly of claim 1 in which the enclosed catalytic combustion chamber has a partially curved and linear shape.

9. The catalytic heating assembly of claim 5 in which the enclosed catalytic combustion chamber having a cylindrically shape has a diameter of about 10 millimeters or less.

10. The catalytic heating assembly of claim 5 in which the enclosed catalytic combustion chamber having a cylindrically shape has a diameter of between about 5 millimeters and about 10 millimeters.

11. A catalytic combustion assembly for heating a stovetop surface, comprising:

a flow-through fuel gas inlet integral with the chamber plate bottom side and a flow-through exhaust outlet integral with the chamber plate perimeter wall;

a plurality of enclosed catalytic combustion chambers integral with the chamber plate. with each enclosed catalytic combustion chamber out of the plurality of enclosed catalytic combustion chambers having at one end a combustion chamber fuel gas opening fluidly connected to the flow-through fuel gas inlet integral with the chamber plate bottom side, and at another end of the enclosed catalytic combustion chamber a combustion chamber exhaust opening fluidly connected to the flow-through exhaust outlet integral with the chamber plate perimeter wall and with no other openings providing access to the enclosed catalytic combustion chamber:

a plurality of catalytic reaction media disposed within a corresponding plurality of the enclosed catalytic combustion chambers;

a combustion starting element disposed within the flow-through fuel gas inlet;

a fuel supply assembly mounted on a fuel supply platform: with the fuel supply assembly having fuel and air mixing injector fluidly connected to the flow-through fuel gas inlet;

whereby the fuel and air mixing injector within the fuel supply assembly can entrain the fuel gas with air and inject a fuel gas and entrained air mixture into the flow-through fuel gas inlet, where the combustion starting element can ignite the fuel gas and entrained air mixture, and ignited fuel gas and entrained air mixture can then flow through the plurality of catalytic reaction media within a corresponding plurality of enclosed catalytic combustion chambers, where the plurality of catalytic reaction media can generate a catalytic combustion process within the corresponding plurality of enclosed catalytic combustion chambers, with the catalytic combustion process transferring heat to the chamber plate top side and integral stovetop surface, and with the stovetop surface for conductively transferring heat to a container.

12. The catalytic heating assembly of claim 11 in which the fuel gas is selected from the group of dimethyl ether, butane, propane and mixtures thereof.

13. The catalytic heating assembly of claim 11 in which the fuel gas has a stoichiometric air to fuel ratio of about 15.

14. The catalytic heating assembly of claim 11 in which the catalytic reaction media comprises a substrate, combined with a catalyst support and an active catalyst.

15. The catalytic combustion assembly of claim 11 in which each enclosed catalytic combustion chamber out of the plurality of enclosed catalytic combustion chambers has an elongate curved shape.

16. The catalytic combustion assembly of claim 15 in which the enclosed catalytic combustion chamber having an elongate curved shape has four elongate sidewall surfaces, with each elongate sidewall surface normal to adjacent sidewall surfaces and opposite from a sidewall surface.

17. The catalytic combustion assembly of claim 16 in which the distance between opposite sidewall surfaces is between about 5 and 10 millimeters.

18. The catalytic combustion assembly of claim 16 in which the distance between opposite sidewall surfaces is about 10 millimeters or less.

19. The catalytic combustion assembly of claim 11 in which each enclosed catalytic combustion chamber out of the plurality of enclosed catalytic combustion chambers has an elongate linear shape.

20. The catalytic combustion assembly of claim 19 in which the enclosed catalytic combustion chamber has an elongate linear shape having four elongate sidewall surfaces, with each elongate sidewall surface normal to adjacent sidewall surfaces and opposite from a sidewall surface.

21. The catalytic combustion assembly of claim 19 in which the top chamber plate top side has an inside surface with a flow diverter integral with the inside surface and positioned at the center of the inside surface.

22. The catalytic combustion assembly of claim 20 in which the distance between opposite sidewall surfaces is between about 5 and 10 millimeters.

23. The catalytic combustion assembly of claim 20 in which the distance between opposite sidewall surfaces is about 10 millimeters or less.

24. A catalytic combustion assembly for heating a stovetop surface, comprising:

a chamber plate enclosure having a chamber plate top and bottom sides, with a chamber plate perimeter wall disposed between and integral with the chamber plate top and bottom sides, and with the stovetop surface integral with the chamber plate top side;

a guide vane ring disposed within the chamber plate enclosure, with the guide vane ring having a plurality of guide vane ring openings and a corresponding plurality of guide vane ring flaps, with each guide vane ring flap out of the plurality of guide vane ring flaps integral at one end with the guide vane ring and with an opposite end of the guide vane ring flap extending away from a guide vane ring opening out of the plurality of guide vane ring openings;

a catalytic combustion chamber within a space within the chamber plate enclosure, with the space defined by the chamber plate perimeter wall, the chamber plate top and bottom sides, and the guide vane ring;

a catalytic reaction media disposed within the catalytic combustion chamber;

a plurality of guide vanes disposed within the chamber plate enclosure and positioned between the guide vane ring and the flow-through fuel gas inlet, with each guide vane out of the plurality of guide vanes adjacent at a proximal end to the flow-through fuel gas inlet and integral at a distal end with the guide vane ring, with each distal end of a guide vane out of the plurality of guide varies positioned such that a guide vane opening out of the plurality of guide vane openings is between distal ends of adjacent guide vanes;

a combustion starting element disposed within the catalytic reaction media;

a fuel supply assembly mounted on a fuel supply platform, with the fuel supply assembly having a fuel and air mixing injector fluidly connected to the fuel gas inlet;

fuel canister sealably connected to the fuel supply platform for supplying a fuel gas to the fuel supply assembly; and

whereby the fuel and air mixing injector within the fuel supply assembly can be used to entrain the fuel gas with air and inject a fuel gas and entrained air mixture through the flow-through fuel gas inlet and cause a flow of the fuel gas and entrained air mixture to pass between the plurality of guide vanes where the flow accelerates; the flow can then pass through the plurality of guide vane ring openings and then flow past the plurality of guide vane flaps, causing the flow to accelerate further; and the flow can then penetrate the catalytic reaction media within the catalytic combustion chamber, where the flow can be ignited by the combustion starting element, generating a catalytic combustion process within the catalytic combustion chamber, with the catalytic combustion process transferring heat to the chamber plate top side and integral stovetop surface, with the stovetop surface for conductively transferring heat to a container.

25. The catalytic combustion assembly of claim 24 in which the fuel gas is selected from the group of dimethyl ether, butane, propane and mixture thereof.

26. The catalytic heating assembly of claim 24 in which the fuel gas has a stoichiometric air to fuel ratio of about 15.

27. The catalytic combustion assembly of claim 24 in which the catalytic reaction media comprises a substrate, combined with a catalyst support and an active catalyst.

26. The catalytic heating assembly of claim 24 in which the catalytic reaction media has a cylindrical ring shape.

29. A method of heating a stovetop surface:

providing for a flow of a fuel gas, with the fuel gas having a stoichiometric ratio of about 15;

increasing the velocity of the flow of the fuel gas;

entraining the flow of the fuel gas with air, thereby creating a flow of fuel gas and entrained air mixture;

maintaining an entrainment ratio of about 15 or above for the flow of fuel gas and entrained air mixture;

constraining the flow of fuel gas and entrained air mixture to an enclosed curved path;

contacting the flow of fuel gas and entrained air mixture with a catalytic reaction media;

igniting the flow of fuel gas and entrained air mixture, thereby generating the catalytic combustion process;

combusting all of the fuel gas during the catalytic combustion process; and

conducting heat from the catalytic combustion process to the stove top.