FR2567251A1 - CATALYTIC CAMPING STOVE - Google Patents

Abstract

A CATALYTIC STOVE 10 INCLUDES A MIXING CHAMBER 18 HAVING AN END SUITABLE FOR RECEIVING A FUEL TANK 12 AND AN OPPOSITE END EQUIPPED WITH A DIFFUSER 28. A PLATE 30, EQUIPPED WITH A GRID INCLUDING FROM 30 TO 60 OPENINGS. , EXTENDS ACROSS THE DIFFUSER EXIT END. A CATALYTIC COATING IS APPLIED TO THE EXIT PORTION OF THE PLATE. THE CATALYST IS CHOSEN FROM THE GROUP INCLUDING PLATINUM, PALLADIUM, RHODIUM AND IRIDIUM.

Description

Catalytic camping stove.

  The present invention relates to camping stoves and more particularly to flameless catalytic stoves. Conventional camping stoves of the type designed to be housed in a backpack or the like have a burner adapted to be screwed on or engaged on

  a metal container containing a fuel source

  target such as propane or butane. Although these

  stoves meet the main objectives of light-

  reté and therefore being easily portable, they present

  have a serious downside, that they have an open flame to generate heat. This flame

  creates a risk of fire, especially when using

  read the stove in a dry place. In addition, the flame may be extinguished, or the heat thereof may be dispersed when there is wind or when it rains. Another disadvantage of these stoves is that their possible adjustment is limited and that therefore

  their combustion takes place almost identically

tick in all conditions.

  In view of the above, it is the main object of the present invention to provide an improved camping stove which is less sensitive to atmospheric conditions than conventional stoves of the type

flame.

  Another object is to provide such a stove, which can more easily be adjusted at will to increase or

decrease the burn rate.

  Another goal is to provide a camping stove whose fuel use is more efficient than in conventional stoves and which releases less

  unpleasant odors than in conventional stoves.

  The above advantages, as well as others, are obtained

  according to the present invention thanks to a cam stove

  ping including an air mixing chamber and

  elongated fuel in the form of an elongated tube.

  A fuel tank connection is provided at the entrance to the chamber. A diffuser surrounds the exit from the room. A plate fitted with a grid covers the outlet end of the diffuser. The plate is a

  monolithic, metallic or ceramic element,

  between 31 and 62 openings per square centimeter, the openings being respectively of the order of 1.52 x 1.52 mm and 1.12 x 1.12 mm. The plate has an outlet face coated with a catalytic coating extending

  in the interstices of the grid. The cata- coating

  lytic is made of platinum, palladium, rhodium or iridium.

  The invention will be better understood on reading the

  detailed description, given below as an example

  only, of a preferred embodiment, in conjunction with the attached drawing in which: - Figure 1 is a side elevational view in simplified section of a catalytic stove according to the present invention; - Figure 2 is a sectional view taken along the reference line 2-2 of Figure 1, in the direction indicated by the arrows; - Figure 3 is a simplified enlarged side elevational view of the stove plate; and - Figure 4 is a partial schematic plan view

  large-scale plate grid.

  Reference is now made to the drawings, and in particular to FIG. 1, on which a stove 10 according to the present invention is seen. The stove is designed to be used with a conventional fuel tank 12, containing butane or liquid propane. For this purpose, the upper part of the reservoir 12 comprises

  a fitting intended to be connected to a corresponding racccrd-

  laying provided at the bottom of the stove. A tap 14 is provided at the inlet of the stove to regulate the flow

  fuel from the tank in the stove.

  The stove has a mixing chamber in the form of an elongated tube 18. An orifice 16 is provided at the entrance to the mixing tube 18 which constitutes the main body of the stove 10. The orifice is fixed and serves to adjust the fuel flow from tank 12, when valve 14 is open. The orifice causes a jet of fuel at high speed, which penetrates

25672S1

  into the tube 18. The ambient air, which enters the tube 18 through an intake opening 20, is sucked into the tube where it mixes with the gas to form a

  combustible mixture. The relative dimensions of the ori-

  fice and tube determine the ratio of air to

  fuel passing through the stove.

  A burner 22 is provided in the form of a perforated truncated cone at the upper end of the tube 18. The

  burner serves as a cap for the tube so that the

  24 holes through the burner constitute the only

  outlet for mixing air and fuel through

  the tube. As can be seen, the perforations 24 are distributed almost uniformly over the

burner surface.

  An ignition opening 26 extends through the burner.

  their 22. A spark igniter, using for example

  A lighter stone or a piezoelectric element may be provided in the ignition opening in a way

  known in conventional gas stoves.

  A diffuser 28, constituted by a reverse truncated cone

  se, extends upwards from the side of the tube 18 adjacent to its upper end. As can be seen, the ignition opening 26 passes through the diffuser. The bottom of the diffuser 28 is tightly fixed on

  the outer surface of the tube 18 so that the diffuse

  seur 28 acts like a directing funnel

  the mixture of air and gas upwards and outwards

  térieur. A plate 30 extends across the end

  open upper part of the diffuser 28. A lining 32 seals the junction of the edge of the plate 30 and a flange 34, which is in turn fixed so

  waterproof on the upper edge of the diffuser or is mono-

  block with him. The rim 34 has spaced projections

  cées 36 which extend beyond the upper face of the plate 30. These projections serve to support the pots or pans which are put to heat on the stove. Figures 3 and 4 show in more detail the plate 30. As can be seen, it is an element in the general shape of a wafer, which can

  be ceramic or metal. This plate is mono-

  lithic, and presents a relatively large number

  so many small through openings. The number

  openings can be in the range of 30 to 60 per cent

  square meter. An important aspect of the present invention

  tion consists in the fact that a catalytic surface is applied in the form of a coating on the face

  outside (i.e. the exit face) of the plate

  than 30 and extends into the interstices of the grid -

  to a depth of approximately 1 to 2 mm. This depth

  is such that the complete combustion of the mixture

  of air and fuel takes place in the presence of the cat-

  lyser. The catalyst is applied only as a surface coating on the plate 30; it can be platinum, palladium or any other rare metal

such as rhodium or irridium.

  In service, the tap is first opened to

  allow fuel to pass from the tank through

  towards the orifice in the mixing tube.

  When the gas passes through the tube, it entrains air, which creates a flammable mixture. The spark igniter is then triggered or a flame is passed through the ignition opening to ignite the air and gas mixture at the top of the burner. After several seconds, the catalyst is hot and the flame is extinguished by cutting off the gas supply. The tap is opened again to reestablish the gas flow and, after a few seconds, the upper portion of the plate 30 glows due to the catalytic combustion which takes place. Food can then be cooked or boiled by placing a saucepan on the jar and casserole supports 36. Heating is effected by radiation and by convection of the heated gases passing in the vicinity

  cooking utensil. Because the present re-

  hot works without flame, it is less sensitive to wind than conventional flame stoves. In addition, the catalytic stove is better regulated than the

  conventional stoves, because it is not necessary

to maintain a flame.

  Thus, the aforementioned goals are effectively achieved.

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Claims (9)

Claims.   1. Catalytic stove (10), characterized in that it   includes: an air and fuel mixing chamber   ble (18) having an inlet and an outlet, a diffuser (28) surrounding the outlet of the chamber, a plate (30) covering the diffuser, this plate having a through opening grid, the internal face of the plate being directed towards the chamber and the exit face of the plate turned in the opposite direction from the   chamber being provided with a catalytic coating extending   dant in the interstices of the grid.   2. Stove according to claim 1, characterized in that it comprises a burner (22) arranged around   leaving the room and inside the diffuser.   3. Stove according to claim 2, characterized in that the diffuser (28) is an inverted truncated cone   and that the burner (22) is a perforated truncated cone.   4. Stove according to claim 1, characterized in   what it includes means for receiving the fuel   ble at the entrance to the chamber, an opening (16) upstream of these fuel receiving means for   accelerate the flow of fuel through the chamber   bre, and an air inlet (20) passing through the chamber, from which it follows that the fuel passing through the chamber entrains the air from the inside from the room.   5. Stove according to claim 2, characterized in that it comprises means for igniting the mixture of air and fuel in the chamber aligned with the burner.   6. Stove according to claim 1, characterized in that it comprises a pan support extending around the grid of the plate, this support comprising support surfaces (36) extending outwards beyond the exit face of the plate. 7. Stove according to claim 1, characterized in   that the plate is a monolithic element comprising   between 31 and 62 openings per square centimeter.   8. Stove according to claim 1, characterized in that the catalytic coating is chosen from the group comprising platinum, palladium, rhodium and iridium.   9. Stove according to claim 1, characterized in that the catalytic coating extends to a depth 1 or 2 mm.