WO2009098168A1 - Fireplace for burning a liquid fuel with air - Google Patents

Abstract

The invention relates to a fireplace of the burner type (1) for burning a liquid fuel, that comprises a combustion chamber (3) in contact with air used as an oxidizer, and an adjustment means arranged so as to maintain, during the entire combustion, the fuel level of the combustion chamber at a level lower than or equal to an upper limit, said upper limit being lower than 15 millimetres.

Description

 CHIMNEY FOR COMBUSTION OF A LIQUID FUEL WITH AIR

The invention relates to a chimney for generating flames from the combustion of a liquid fuel disposed in contact with the air.

The invention is particularly applicable to fireplaces operating with vegetable type alcohol fuel. These fireplaces are mainly intended for decorative use to create an indoor environment or outdoor living. They can be placed in a fireplace hearth, or in any decorative element. Their size is limited and their handling is easy, they can easily be integrated into any type of decor.

These chimneys are commonly referred to as "ductless chimneys", "liquid fuel fireplaces" or "burners". In the following description they are designated burners but should not be assimilated to burners including industrial whose constraints are far removed from those chimneys object of the present invention.

In known manner, burner type chimneys comprise a combustion chamber for receiving a liquid fuel whose free surface is disposed in contact with the air. Ignition of a flame in the vicinity of the free surface of the fuel causes combustion of the fuel with air.

The purpose of these burners is essentially decorative, it would be appreciated to be able to generate a fire approaching that of a wood fire, presenting flames whose color is yellower than those of the fire produced by conventional burners .

To achieve this objective, it is provided in the case of the present invention a burner-type chimney for liquid fuel combustion, comprising a combustion chamber arranged in contact with air as an oxidizer, the chimney comprising continuous control means arranged so as to maintain substantially throughout the combustion the fuel level of the combustion chamber at a level less than or equal to an upper limit, said upper limit being less than 15 millimeters.

However, the applicant realized that by regulating the level of fuel in the chamber so as to keep it below or at the same level as said upper limit, a fire is generated which continuously generates a flame of significantly yellowish color. a fire produced by conventional flueless chimneys.

The chimney according to the invention may also optionally have at least any of the following characteristics: the upper limit is less than 8 millimeters, the upper limit is less than or equal to 5 millimeters and the control means are arranged so that in operation the fuel level of the combustion chamber is greater than or equal to a lower limit which is greater than or equal to 1 millimeter,

the chimney comprises measurement means arranged to determine the level of fuel contained in the combustion chamber, the chimney comprises feed means arranged to feed the fuel chamber when they are activated, and in which the regulating means are arranged to activate the supply means so as to maintain said fuel level of the fuel chamber; combustion between said upper limit and a predetermined lower limit,

the chimney comprises a fuel tank fluidly connected to the combustion chamber to allow fuel to be supplied to the combustion chamber and in which the supply means comprise a pump arranged between the tank and the combustion chamber;

the chimney comprises a buffer tank fluidly connected with the combustion chamber so that the free surface of the fuel of the buffer tank and that of the fuel of the combustion chamber remain by gravity substantially in the same horizontal plane; measurement comprise at least one sensor arranged in the buffer tank and arranged to measure the level of fuel in the buffer tank,

the buffer tank is arranged between the combustion chamber and the pump; the chimney comprises a fuel supply duct, one end of which forms a fuel inlet for the combustion chamber, as well as a flap shaped on said inlet; in order to ensure that the flame is extinguished by smothering at said input,

- The chimney comprises a supply duct shaped to act as a siphon between the combustion chamber and the buffer tank so as to prevent the passage of hot gases or flames between the combustion chamber and the buffer tank.

It is further provided according to the invention a method for ensuring the combustion of a liquid fuel with air in a liquid fuel burner type chimney having a combustion chamber disposed in contact with the air acting as an oxidizer and wherein the fuel level in the combustion chamber is regulated so that level remains, at the time of combustion, at a level less than or equal to an upper limit, said upper limit being less than 15 millimeters.

Other characteristics, objects and advantages of the present invention will appear on reading the detailed description which follows and with reference to the appended drawings given by way of non-limiting example and in which:

FIG. 1 is a perspective view of a chimney according to an exemplary embodiment of the invention,

FIG. 2 is a perspective view of the chimney illustrated in FIG. 1 and in which the upper plate has been taken; FIG. 3 is a perspective view of the chimney illustrated in FIG.

1 in which the housing has been removed,

FIG. 4 is a side view of the chimney illustrated in FIG. 1 and in which the housing has been removed,

FIG. 5 is a view along a longitudinal section of the chimney illustrated in FIG. 1;

- Figure 6 is a view in a cross section of the fireplace shown in Figure 1.

With reference to FIGS. 1 to 6, an example of a chimney according to the invention is illustrated. As a reminder, in the present application by burner 1 denotes a chimney type duct whose vocation is mainly aesthetic and decorative.

The burner 1 according to the invention comprises a combustion chamber 3. The combustion chamber 3 comprises a bottom 4 and side walls defining a volume for receiving a liquid fuel. The combustion chamber 3 also has an opening to allow the fuel to mix with the air of the surrounding medium. During operation the fuel rests in the volume defined by the bottom and the walls. The volume contains only fuel and air during operation. Inside the chamber the fuel can move freely.

When a flame or spark is approaching the free surface of the fuel, combustion is triggered between the fuel and the air acting as an oxidizer. Only air in the vicinity of the free surface of the fuel participates in the combustion. The chimney does not require a device for injecting, feeding or propelling air in the vicinity of the fuel. The combustion chamber is largely open and the air naturally present near the free surface of the fuel is sufficient to ensure the desired combustion. During operation, the fuel located near the free surface may be in the gaseous state.

Advantageously, the fuel used is alcohol of vegetable origin. The burner according to the invention can work with many other liquid fuels. The burner 1 comprises regulating means able to ensure a continuous regulation of the fuel level in the combustion chamber 3. These means substantially maintain throughout the combustion fuel at a level less than or equal to a predetermined upper limit.

The fuel level is defined by the distance between the free surface of the fuel and the bottom 4 of the combustion chamber 3. This upper limit is less than 15 millimeters

However, the applicant unexpectedly found that when maintaining a fuel level of less than 15 millimeters during the combustion, the resulting fire has a color that is substantially yellower than the heat of the existing burners.

This color helps to recreate a fire close to the wood fires. It thus improves the quality of the atmosphere generated by the existing burners.

In addition, maintaining the fuel level below this predetermined upper limit also makes the flames more vivid and more daring than existing burners.

The invention also makes it possible to obtain a fire producing a significantly greater crackling than in the fires generated by conventional burners. Advantageously, the upper limit is less than or equal to

8 millimeters which makes the flames even more dancing and yellow and increase crackling. Furthermore, the continuous regulation means are arranged so that the fuel level in the combustion chamber 3 is greater than or equal to a predetermined lower limit. This lower limit is between 1 millimeter and 10 millimeters. Advantageously it is between 1 and 4 millimeters. Even more advantageously, it is equal to 1 millimeter.

Preferably, the upper limit is substantially equal to 5 millimeters and the lower limit is substantially equal to 1 millimeter. Particularly advantageously, the lower and upper limits are equal to 4 millimeters so that the fuel level in the combustion chamber 3 remains substantially equal to 4 millimeters.

With such a regulation of the fuel level, the fire generated by the burner 1 has surprising qualities in terms of liveliness, color and crackling. Furthermore, the regulation of the fuel level between relatively close lower and upper limits allows to maintain a high stability of these qualities throughout the combustion.

The burner 1 comprises a reservoir 2 disposed in fluidic relation with the combustion chamber 3 so as to supply the latter with fuel. Advantageously, the burner 1 comprises a pump 14 for transferring the fuel from the tank 2 to the combustion chamber 3. Preferably, the tank 2 has a volume significantly greater than that of the combustion chamber 3. It is arranged in the lower part of the burner 1. It serves as a frame and has an upper face on which are mounted the other organs of the burner 1.

Thus, the burner 1 comprises a support 15 secured to the casing 30 and arranged to receive and raise the combustion chamber 3 relative to this same upper face.

The pump 14 is also removably mounted on one of the faces of the casing 30.

The regulating means comprise measurement means arranged to determine the fuel level contained in the combustion chamber 3, emitting a first signal when said level reaches said limit higher, and emit a second signal when said level reaches said lower limit,

The regulating means also comprise control means arranged to receive the signals emitted by the measuring means and to control the transfer of fuel from the tank 2 to the combustion chamber 3, or to control the transfer of fuel from the chamber of combustion 3 to the tank 2, so that the fuel level in the combustion chamber 3 remains between the upper and lower limits substantially throughout the combustion. Furthermore, this level regulation allows the maintenance in the combustion chamber 3 of a small amount of fuel. The thermal inertia of the fuel volume present in the combustion chamber 3 is therefore also limited.

Thus, after stopping the combustion, the temperature of the fuel present in the combustion chamber 3 decreases more rapidly than in existing burners whose combustion chamber is intended to accommodate a large amount of fuel.

However, the evaporation of fuel increases significantly with its temperature. The invention thus makes it possible to significantly limit the evaporation of fuel.

Preferably, to stop the device is stopped to fuel the combustion chamber fuel and not oxidizer as on most existing burners. Thus, it is only when the stopping of combustion is controlled that the fuel level falls below said lower limit.

In order to accelerate the extinction, the pump 14 extracts the fuel from the combustion chamber 3. This extraction of the fuel, in addition to preventing any unintentional restart of the combustion, considerably reduces the evaporation of fuel at air contact when combustion is stopped. Thus the fuel level is maintained between the lower and upper limits throughout the combustion except during the extinction phase and possibly during the ignition phase. The control means comprise an electronic card for processing the signals received by the measuring means and for controlling the activation of the pump 14 to transfer the fuel.

The electronic card is removably attached to the housing 30. The measuring means comprise at least one level sensor 12.

Advantageously, the burner 1 comprises a buffer tank 10 arranged in fluid communication with the tank 2 and with the combustion chamber 3. The buffer tank 10 comprises a bottom 11, an upper face and side faces. It is intended to contain fuel. It is arranged so that the free surface of the fuel it contains is, by gravity, substantially in the same plane as the free surface of the fuel present in the combustion chamber 3.

Thus, the level of fuel in the buffer tank 10 makes it possible to determine the level of fuel contained in the combustion chamber 3. Advantageously, the sensor 12 is disposed at the level of the buffer tank 10. Thus, it makes it possible to reflect the fuel level in the combustion chamber 3 while being deported out of the latter which may be subject to significant constraints including heat.

A first conduit 16 fluidly connects the reservoir 2 to the pump 14. A second conduit 18 fluidly connects the pump 14 to the bottom of the buffer tank 10. A third conduit 5 fluidly connects the bottom 11 of the buffer tank 10 to the bottom 4 of the chamber 3. Advantageously, the third conduit serves as a siphon to prevent the spread of fire and gases from the combustion chamber 3 to the buffer tank 10. Preferably, the pump 14 is a peristaltic pump. It thus makes it possible to supply and empty the combustion chamber 3. Furthermore, it makes it possible to hermetically partition all the fuel included in the combustion chamber 3, the third duct 5, the buffer tank 10, the second duct 18 , relative to all the fuel included in the first conduit 16 and in the reservoir 2. The use of such a pump does not require sealing between cooperating parts in motion. It therefore reduces the risk of leaks, reduces maintenance and improves the life of the burner. The burner 1 further comprises a control panel 22 which acts as a control and signaling interface between the user and the burner 1. The console is connected to the electronic card and comprises display means for signaling to the user. the user any malfunction and possibly the mode of operation chosen. The console further comprises a button for controlling the start or stop of the combustion.

Preferably, it is provided that when the user controls the stopping of the combustion via the control panel 22, the electronic card triggers the activation of the pump 14 so that the latter empties the fuel. present in the combustion chamber 3 and the buffer tank 10. When the chamber 3 no longer has fuel, the fire stops.

Moreover, any inadvertent restart of the fire is made impossible even when the combustion chamber 3 is raised to a high temperature. This feature provides additional security.

Thus, between two uses of the burner 1 the combustion chamber 3 remains empty. At a later start of the burner 1, the user controls, via the interface, the electronic board to engage the pump 14 to transfer fuel from the tank 2 to the combustion chamber 3 .

Fuel contained in the tank 2 is then transferred from the latter to the first duct 16 and then to the pump 14 and then to the second duct 18 then to the buffer tank 10 and then to the third duct 5 and finally to the combustion chamber 3.

When the level sensor 12 detects that the level in the buffer tank 10 corresponds to a fuel level in the combustion chamber 3 which substantially reaches said upper limit, the control means stop the activation of the pump 14. During the combustion, some of the fuel is consumed. Consequently, the level of the latter drops in the combustion chamber 3 and causes the fuel level in the buffer tank 10 to decrease. At regular time intervals, the detection means check whether the level of fuel in the combustion chamber 3 is well between said lower and upper limits. When the measuring means detect that the fuel level in the buffer tank 10 corresponds to a fuel level in the combustion chamber 3 which is less than or equal to said lower limit, the control means trigger the activation of the pump 14 in order to fill the combustion chamber 3.

Thus, throughout the combustion the fuel level in the combustion chamber 3 is maintained substantially between the lower and upper limits. Therefore, the invention makes it possible to perfectly control the behavior of the fire throughout the operation of the burner 1.

Optionally, the burner 1 according to the invention comprises a closure flap of the combustion chamber 3. This closure flap cooperates with a lever 7 that the user is intended to activate when it wishes to reduce the flame. When the handle 7 is activated, the shutter closes the chamber partially or completely.

Advantageously, the support 15 is arranged to be able to position in a simple, precise and stable way the combustion chamber 3 and the buffer tank 10. The support 15 can be obtained by laser cutting in particular. Preferably, the burner 1 comprises an upper housing 30 and a plate 31. The housing 30 has side walls. It is intended to cooperate with the tank 2 to be placed above the latter and to house the first 16, second 18 and third 5 ducts, the control means, the pump 14, the buffer tank 10 and the combustion chamber 3 The plate 31 is shaped to cooperate with the side walls of the casing 30 so as to cover the different members of the burner 1. Recesses are made in the plate 31 and the casing 30 to leave free access to the combustion chamber 3, a filling port 17 of the tank 2, the control panel 22 and aeration zones. The main purpose of the aeration zones is to contribute to the cooling of the electronic part of the burner. The burner is arranged so that as little heat as possible is transferred from the combustion chamber 3 to the other particular electrical organs. Thus, the contact area between the combustion chamber 3 and the support 15 is deliberately limited, and the convection exchanges with the outside are favored.

The invention as described above improves the fire control generated by a burner 1. Moreover it has a limited size and simplicity.

Optionally and independently of the control means described above, the burner 1 comprises means for stopping the combustion by smothering when there is only little fuel in the combustion chamber 3. These means generally have a flap 6 covering the orifice through which the combustion chamber 3 communicates with its supply duct 5. These means also allow fluid communication between the combustion chamber 3 and its supply duct 5.

The flap 6 may be attached to the bottom 4 of the combustion chamber 3. Preferably it is obtained by V-folding a sheet.

It has for example a cylinder portion shape extending along an axis substantially parallel to the plane of the bottom 4 of the combustion chamber 3 and whose ends are open.

By limiting the communication of air between the combustion chamber 3 and the supply duct 5, these means prevent the spread of fire in the supply duct 5.

The present invention is not limited to the embodiments described above, but extends to any embodiment within its spirit.

In particular in an alternative embodiment it is provided that an upper reservoir is arranged relative to the combustion chamber 3 so that the latter can be filled by gravity by the tank. A valve, controlled by the control means, then regulates the supply of the combustion chamber 3.

Furthermore, it is possible to provide a lower reservoir and a second valve arranged in fluid communication with the combustion chamber and in such a way that the control means trigger the opening of the valve when the fuel level in the combustion chamber combustion reached or is greater than said upper limit so that the fuel of the combustion chamber 3 passes, by gravity, into the lower tank.

Although the chimney object of the present application is primarily intended for decorative use, it can serve, additionally, as auxiliary heating.

The invention is not limited to burners whose combustion chamber 3 has a flat bottom 4.

If the bottom 4 of the combustion chamber 3 is not flat, the fuel level, within the meaning of the present application, then relates to a sufficiently large area for the effects of the invention to manifest substantially.

The burner 1 comprises connection means to a power source for operating the pump 14, the control means, the measuring means and optionally the ignition. Additionally or alternatively, the burner 1 comprises a battery or batteries housed in a battery compartment 21.

In another alternative embodiment, it can be provided that the combustion chamber 3 is arranged to house the fire. Glass walls can then be provided to allow a good vision of the flames.

REFERENCES

1. Burner

2. Tank 3. Combustion chamber

4. Background

5. Feed duct

6. Bib

7. Joystick

10. Buffer tank

11. Bottom of the buffer tank

12. Level sensor

14. Pump

15. Support

16. First conduit

17. Filling hole

18. Second conduit

20. Case

21. Battery compartment

22. Control panel

30. Carter

31. Platinum

Claims

1. Burner type chimney (1) for liquid fuel combustion, comprising a combustion chamber (3) arranged in contact with the air acting as an oxidizer, characterized in that it comprises regulating means arranged so as to maintaining throughout the combustion the fuel level of the combustion chamber (3) at a level less than or equal to an upper limit, said upper limit being less than 15 millimeters and at a level greater than or equal to a lower limit, said lower limit being equal to 1 millimeter. 2. Chimney according to the preceding claim wherein the upper limit is less than 8 millimeters. 3. Chimney according to the preceding claim wherein the upper limit is less than or equal to 5 millimeters. 4. Chimney according to any one of the preceding claims comprising measuring means arranged to determine the level of fuel contained in the combustion chamber (3). 5. Chimney according to any one of the preceding claims comprising feed means arranged to supply the fuel chamber when activated, and wherein the control means are arranged to activate the supply means so as to maintain the fuel of the combustion chamber (3) at a level less than or equal to said upper limit. 6. Chimney according to the preceding claim comprising a tank (2) of fuel fluidly connected to the combustion chamber. (3) for fueling the combustion chamber (3) with fuel and wherein the supply means comprises a pump (14) disposed between the reservoir (2) and the combustion chamber (3). Chimney according to any one of the preceding claims, comprising a buffer tank (10) fluidically connected with the combustion chamber (3) so that the free surface of the fuel of the buffer tank (10) and that of the fuel of the combustion chamber (3) remain by gravity substantially in the same horizontal plane. 8. Chimney according to the preceding claim comprising a supply duct (5) between the combustion chamber (3) and the buffer tank (10) in fuel, one end of which forms a fuel inlet for the combustion chamber (3), and a flap (6) shaped on said inlet so as to extinguish the fire by smothering at said inlet of the supply duct (5). A chimney according to any one of the preceding claims taken in combination with claim 4 in which the measuring means comprise at least one sensor arranged in the buffer tank (10) and arranged to measure the level of fuel in the buffer tank ( 10). A method for combusting a liquid fuel with air in a liquid fuel burner (1) chimney having a combustion chamber (3) disposed in contact with the oxidizing air, characterized in that throughout the combustion the fuel level in the combustion chamber (3) is regulated so that said level is lower than or equal to an upper limit, said upper limit being less than 15 millimeters.