EP0520913B1 - Heating device with catalytic burner - Google Patents

Abstract

Heating device comprising a catalytic burner (1) and a thermal receiver (2) consuming at least a part of the heat generated by the catalytic burner, the latter comprising a member (3) for ejection of a flow of combustible gas, a member (4) for admixing primary air to said flow to obtain a mixture to be burned, a chamber (5) for distribution of said mixture, and a structure (6) for catalytic combustion, traversed by the mixture, from its upstream face (6a) in association with the distribution chamber (5) to its downstream face (6b) which discharges the combustion fumes, characterised in that, the radiating front (10) of combustion without flames being situated when operating close to the upstream face of the structure for catalytic combustion, the thermal receiver (2) extends opposite the upstream face (6a) of the catalytic structure (6), over virtually the entire surface of the latter, so as to receive the thermal energy emitted by the radiating front, and said receiver is arranged and constructed to dissipate, on the opposite side (2b) to the upstream face (6a) of the catalytic structure, at least 30% of the thermal energy received by radiation from the radiating front. <IMAGE>

Description

The present invention relates to a heating device with a catalytic burner.

By "heater" is generally meant any device, portable or not, integrating or connected to a source of combustible gas, using the heat of combustion produced by the catalytic burner for different purposes, such as cooking, heating, welding, generation of hot air, crimping of the hair, etc., and possibly comprising other elements or members allowing the use of said device for the chosen end or destination, for example a soldering failure, if the use selected for the device is welding.

"Catalytic burner" means any assembly making it possible to burn a combustible gas, by mixing the latter with so-called primary air, upstream of a catalytic structure, flameless combustion of said mixture during its passage through the catalytic structure, and evacuation of combustion fumes by the downstream face of this same structure. Such a burner according to the invention, known as "induced air", must be distinguished from so-called "secondary air" catalytic burners, for which the combustible gas passes directly through the catalytic structure, and is burnt without flame on the face downstream of said catalytic structure, by mixing with ambient air.

By "catalytic structure" or "catalytic combustion structure" is meant any structure permeable to the mixture to be burned, and sufficiently thick to generate a pressure drop during the passage of said mixture, from the upstream face to the downstream face of said structure. This structure extends on the surface transversely or perpendicular to the direction of passage of the mixture to be burned. This structure comprises a support which is inert with respect to the mixture to be burned, combustible gas, and combustion gases, and which is mechanically resistant to the high temperatures generated by catalytic combustion. This support is coated, at least on its internal surface or surfaces, directly or indirectly, with an actual catalytic material, such as platinum or platinum salts, catalyzing combustion.

Relate from the previous definition, on the one hand the catalytic structures, called "honeycomb", consisting of a slice or a core of a refractory material such as ceramic, crossed by a plurality of adjacent transverse channels, and on the other hand structures of the tissue or catalytic sieve type.

• un brûleur catalytique, constitué par un organe d'éjection, tel qu'un injecteur, d'un flux de gaz combustible, un organe tel qu'un venturi, d'admixtion d'air primaire au flux de gaz combustible, pour obtenir un mélange à brûler, une chambre de distribution de ce dernier, et une structure catalytique du type "nid d'abeille", traversée par le mélange, de sa face amont en relation avec la chambre de distribution, à sa face aval évacuant les fumées de combustion
• et une enveloppe métallique entourant le brûleur catalytique, recevant la chaleur de combustion par conduction, convection des fumées de combustion, et rayonnement, et dissipant la chaleur reçue vers la panne de soudure, pour la consommer à cet endroit en fonction des travaux de soudure effectués.

In accordance with document FR-A-2 621 981 (& EP-A-0 313 479), a portable soldering iron type heating appliance has been described, comprising:

• a catalytic burner, constituted by an ejection member, such as an injector, from a flow of combustible gas, a member such as a venturi, for admixing primary air to the flow of combustible gas, in order to obtain a mixture to be burned, a distribution chamber of the latter, and a catalytic structure of the "honeycomb" type, crossed by the mixture, from its upstream face in relation to the distribution chamber, to its downstream side discharging the fumes of combustion
• and a metal casing surrounding the catalytic burner, receiving the heat of combustion by conduction, convection of combustion fumes, and radiation, and dissipating the heat received towards the soldering tip, for consuming it there according to the welding work carried out .

Induced air catalytic burners, including the one described above, are characterized by a high specific calorific power, that is to say per unit area, between 10 and 100 W / cm². Such a high specific power does not pose too many problems, as long as the surface of the catalytic structure remains relatively small. This power becomes an obstacle, as soon as one exceeds a certain surface of the catalytic structure, due to the significant heating observed on the device.

Such heating can be easily explained for a circular or cylindrical catalytic structure, having a constant thickness, by the fact that the calorific power obtained increases with the square of the diameter, while the exchange surface of the burner with the walls and the receiver thermal consuming combustion heat increases with diameter.

• il diminue la durée de vie de la structure catalytique, composant essentiel de l'appareil de chauffage
• il oblige à prévoir sur l'appareil différents moyens de protection thermique
• il entraîne des prises de feu en amont de la structure catalytique, dans la chambre de distribution du mélange à brûler, par exemple.

This overheating is obviously damaging for several reasons:

• it decreases the service life of the catalytic structure, an essential component of the heater
• it requires to provide on the device different means of thermal protection
• it causes ignitions upstream of the catalytic structure, in the distribution chamber of the mixture to be burned, for example.

For all these reasons, as soon as the surface of a catalytic structure as defined above exceeds a certain value, for example 20 cm 2, it becomes absolutely necessary to cool the catalytic burner. And this is the object of the present invention.

After having tried different means of cooling having proved ineffective, complicated, or too expensive, the Applicant has arrived at the following discovery, supporting the solution adopted according to the invention.

The device heats up mainly upstream of the catalytic structure, because in fact, in the thickness of the latter and in the direction of passage of the mixture to be burned, there is a radiant front of combustion without flames, nearby immediately upstream of said catalytic structure. And the rest of the thickness of the catalytic structure only serves to complete the combustion and evacuate the fumes.

Consequently, any cooling of the device passes through the evacuation of the heat radiated by the upstream face of the catalytic structure. To do this, evacuation by the thermal receiver of the device, that is to say the part which consumes or uses the calories produced by combustion, conventionally arranged downstream of the catalytic structure appears to be the best solution.

According to the invention, firstly a reverse operation is chosen, in particular upside down of the catalytic burner previously described, in that, on the one hand, the thermal receiver extends opposite the upstream face (and not downstream face) of the catalytic structure, along practically the entire surface of the latter, so as to receive the radiated thermal energy emitted by the radiant front of combustion of the catalytic structure in operation. Finally, for its part, the receiver is chosen, arranged, or constructed to dissipate, on the side opposite the upstream face of the catalytic structure, at least 30% of the thermal energy received by radiation from the radiating front. Preferably, the thermal receptor is an element in vitro-ceramic.

Such a configuration also brings the following decisive advantages.

The mixture to be burned being introduced into the burner, by the downstream side of the catalytic structure, is only in thermal relation with the upstream face of the latter at the last moment, that is to say just before its combustion; under these conditions, the mixture to be burned is at a relatively lower temperature in the distribution chamber, which significantly reduces the catches of fire upstream of the catalytic structure.

As the catalytic burners are radiant burners at relatively low temperature, and as according to the present invention, the thermal receiver is arranged opposite the most radiant side, that is to say the upstream side, so a heating device according to the invention has a good combustion efficiency.

In summary, the solution according to the invention makes it possible both to reduce the risk of catching fire upstream of the catalytic structure, and to increase the efficiency of the catalytic burner, which is never encountered for a catalytic burner classic induced air.

• recevoir et absorber la chaleur émise par rayonnement par la face amont de la structure catalytique
• dissiper cette chaleur reçue, dans la proportion d'au moins 30 %, du côté opposé à la face amont de la structure catalytique, par conduction et/ou transmission de la chaleur absorbée, par exemple vers une charge thermique, telle qu'un récipient à chauffer.

According to the invention, the thermal receptor is any structure or any material having the capacity to:

• receive and absorb the heat emitted by radiation from the upstream face of the catalytic structure
• dissipate this heat received, in the proportion of at least 30%, on the side opposite the upstream face of the catalytic structure, by conduction and / or transmission of the absorbed heat, for example towards a thermal load, such as a container to heat.

In particular, a thermal receptor made of a ceramic-ceramic material completely meets these requirements, but also a metal plate blackened on both sides.

A preferential version still has the following technical characteristics.

First of all, a combustion smoke deflector is arranged opposite the downstream face of the catalytic structure, to return said smoke from the upstream side of said structure, outside the combustion chamber. distribution.

In fact, the Applicant's experiments have shown that a heating device according to the invention dissipates about a good third of the heat produced by catalytic combustion by convection, that is to say in combustion fumes. Consequently, the return of the fumes in direction of use, that is to say on the external side of the thermal receiver, makes it possible to improve the efficiency of the heating appliance, in significant proportions; this appears particularly important for a heating appliance of the cooking stove type.

• pour un réchaud de cuisson, et en termes de performances, on recherche les temps de cuisson les plus courts possibles, par exemple un temps minimum pour faire bouillir un litre d'eau, toutes choses égales par ailleurs
• ce temps de cuisson est inversement proportionnel, et au rendement de l'appareil, et à la puissance spécifique ; donc un gain de 1 % en rendement équivaut à un gain de 1 % en puissance spécifique, vis-à-vis du temps de cuisson
• mais toute augmentation de la puissance spécifique, d'une part diminue la durée de vie du brûleur catalytique, et d'autre part provoque beaucoup plus vite l'apparition de prises de feu en amont de la structure catalytique, et ce dans une proportion beaucoup plus importante que le taux d'augmentation de la puissance spécifique; aussi une augmentation de 15 % de la puissance spécifique conduit à diminuer d'environ la moitié la durée de vie de la structure catalytique
• dans ces conditions, l'augmentation du rendement obtenue comme précédemment permet de préserver ou limiter la puissance spécifique du brûleur catalytique, et donc à augmenter la durée de vie de ce dernier, à performance sensiblement égale du réchaud de cuisson.

As it is specifically a cooking stove, the increase in the efficiency of the heating appliance, obtained by the deflection of combustion fumes, appears to be very advantageous for the catalytic burner proper, for the following reasons:

• for a cooking stove, and in terms of performance, we seek the shortest possible cooking times, for example a minimum time to boil a liter of water, all other things being equal
• this cooking time is inversely proportional, both to the efficiency of the appliance, and to the specific power; therefore a gain of 1% in yield is equivalent to a gain of 1% in specific power, with respect to the cooking time
• but any increase in the specific power, on the one hand shortens the life of the catalytic burner, and on the other hand causes much faster the appearance of catches of fire upstream of the catalytic structure, and this in a proportion much greater than the rate of increase in specific power; also a 15% increase in specific power leads to a reduction of the service life of the catalytic structure by approximately half
• under these conditions, the increase in yield obtained as above makes it possible to preserve or limit the specific power of the catalytic burner, and therefore to increase the life of the latter, at substantially equal performance of the cooking stove.

Another preferred embodiment also presents the following means making it possible to improve the efficiency of a heating appliance according to the invention.

First of all, the combustion smoke deflector is thermally insulated, not only to limit the outside temperature of the walls of the heater, but also to lose the least sensible heat in the combustion smoke.

Then, the heater can include heat exchange means, for example fins, between, on one side inside the distribution chamber, and on the other side the combustion fumes returned to the upstream side of the catalytic structure, generally cooler. This means not only improves the overall efficiency of the heating device, but also cools the distribution chamber, which limits the possibilities of catching fire upstream of the catalytic structure. With regard to the cooling of the distribution chamber, it is significant, since the life of the catalytic structure is almost doubled with heat exchange fins, all other things being equal.

• la figure 1 représente, de manière schématique, une vue en coupe verticale d'un appareil de chauffage selon la présente invention, du type réchaud de cuisson
• la figure 2 représente une vue en coupe horizontale, selon la ligne II.II de la figure 1, du réchaud de cuisson représenté à la figure 1.
• de manière similaire aux figures 1 et 2 respectivement, les figures 3 et 4 représentent un autre réchaud de cuisson conforme à la présente invention.

The present invention is now described by way of example, with reference to the accompanying drawings, in which:

• Figure 1 shows, schematically, a vertical sectional view of a heater according to the present invention, of the cooking stove type
• FIG. 2 represents a view in horizontal section, along line II.II of FIG. 1, of the cooking stove shown in FIG. 1.
• similarly to Figures 1 and 2 respectively, Figures 3 and 4 show another cooking stove according to the present invention.

The heating appliance shown in FIGS. 1 and 2 generally comprises, on the one hand, a catalytic burner 1, more particularly described below, and a thermal receiver 2, constituted by a circular wafer of a vitro-ceramic, this receiver consuming at least part of the heat generated by the catalytic burner 1, and being arranged to receive a thermal load on its external face 2b, for example a container in which cooking is carried out.

The assembly described above is arranged vertically, the thermal receiver 2 is placed above the catalytic burner 1, and the gas circulation takes place vertically, from top to bottom, then from bottom to top as described below; and the thermal receiver 2 is arranged substantially horizontally.

• un organe 3 d'éjection d'un flux ou jet de gaz combustible, par exemple un injecteur
• un organe 4 d'admixtion d'air primaire au flux de gaz combustible, pour obtenir un mélange à brûler, circulant dans un conduit 7, disposé selon l'axe de la galette 2 en vitro-céramique ; cet organe d'admixtion consiste simplement en un espace ménagé entre la sortie de l'injecteur 3 et l'entrée du tube 7, de manière à y introduire de l'air primaire, par l'aspiration provoquée par l'éjection du flux de gaz combustible
• une chambre de distribution 5, ayant la forme d'un cylindre, disposée entre la galette 2, ou récepteur thermique, et la structure catalytique 6 décrite ci-après ; cette chambre de distribution communique avec la sortie du tube 7, et permet de répartir le mélange à brûler selon toute la surface de la structure catalytique 6
• la structure de combustion catalytique 6, consistant en une galette d'un matériau réfractaire, du type céramique, comportant une pluralité de canaux la traversant de part en part perpendiculairement à sa surface d'extension, et lui conférant une structure du type nid d'abeille ; la surface interne des canaux 6c de cette galette, est revêtue directement ou indirectement avec une matière catalytique de combustion, par exemple du platine ; cette galette ou structure catalytique 6 est disposée parallèlement à la galette 2 ou récepteur thermique, de manière coaxiale, et est traversée en son centre par l'extrémité de sortie du tube 7 ; comme montré par la figure 1, la galette 6 est traversée par le mélange à brûler, de sa face amont 6a à sa face aval 6b évacuant les fumées de combustion, c'est-à-dire de haut en bas.

The catalytic burner 1 comprises or combines:

• a member 3 for ejecting a stream or jet of combustible gas, for example an injector
• a member 4 for admixing primary air to the flow of combustible gas, in order to obtain a mixture to be burned, circulating in a duct 7, arranged according to the axis of the wafer 2 in vitro-ceramic; this admixture member simply consists of a space formed between the outlet of the injector 3 and the inlet of the tube 7, so as to introduce primary air therein, by the suction caused by the ejection of the flow of combustible gas
• a distribution chamber 5, in the form of a cylinder, disposed between the wafer 2, or thermal receptor, and the catalytic structure 6 described below; this distribution chamber communicates with the outlet of the tube 7, and makes it possible to distribute the mixture to be burned over the entire surface of the catalytic structure 6
• the catalytic combustion structure 6, consisting of a wafer of a refractory material, of the ceramic type, comprising a plurality of channels passing right through it perpendicularly to its extension surface, and giving it a structure of the nest type bee; the internal surface of the channels 6c of this wafer, is coated directly or indirectly with a catalytic combustion material, for example platinum; this wafer or catalytic structure 6 is arranged parallel to the wafer 2 or thermal receptor, coaxially, and is crossed in its center by the outlet end of the tube 7; as shown in Figure 1, the wafer 6 is crossed by the mixture to be burned, from its upstream face 6a to its downstream face 6b discharging the combustion fumes, that is to say from top to bottom.

In accordance with the invention, in relation to the catalytic combustion front 10 inside and near the upstream face 6a of the catalytic structure 6, the thermal receiver 2 extends opposite the upstream face 6a above, along virtually the entire surface of the latter, so as to receive the radiated thermal energy emitted by the radiant front of combustion of the catalytic structure in operation.

From this arrangement, various complementary technical characteristics make it possible to transfer the combustion heat to the thermal receiver 2 and a thermal load (for example a pan to be heated) placed on the outside of said receiver, by convection and conduction.

A deflector 8 of the combustion fumes leaving the downstream face 6b of the catalytic structure 6 is disposed opposite and at a distance of this downstream face. This deflector 8, by its shape shown by way of example in FIG. 1, associating from the inside towards the outside a conical part 8a directed downwards and another part 8b directed upwards, makes it possible to return the fumes on the upstream side of the structure 6, and outside of the distribution chamber 5. The fumes thus returned are used to heat the thermal load, for example a pan, the contents of which are to be heated or reheated, present on plate 2 in vitro-ceramic.

This deflector 8 also serves as a reflective screen, placed facing the downstream face 6b of the catalytic structure 6, for reflecting the radiation emitted by this downstream face, still outside the distribution chamber 5.

The catalytic burner 1 comprises means 9 for the return of combustion fumes. These means consist of an annular channel determined between an internal metallic ferrule 12 closing the distribution chamber 5, and an external metallic ferrule 13. The apparatus according to FIGS. 1 and 2 also includes heat exchange means, between the inside of the distribution chamber 5 and the combustion fumes circulating in the abovementioned annular channel; these means consist of a plurality of radial fins 11, in thermal contact with the wall 12, around the flattened cylindrical volume determined by the two wafers 6 and 2, between the internal metallic ferrule 12 and the external metallic ferrule 13, so as to provide between the fins 11 circulation passages. These fins 11 make it possible to extract heat from the distribution chamber 5, to heat the fumes, and thus increase the supply of heat by convection to the thermal load.

By eliminating the shell 13, the circulation means 9 can also be eliminated, while retaining the radial fins 11 of heat exchange.

Thanks to these joint arrangements, the heat developed by the combustion front 10, and consequently by the catalytic burner, is transferred to the thermal receiver 2, and to the thermal load present on the latter, mainly by radiation between the upstream face 6a. of the catalytic structure 6 and the internal face 2a of the receiver, but also for another part by the combustion fumes which bring their heat to the receiver 2 and to the thermal load, and for a last part by metallic conduction between structure 6 and receiver 2.

• la face interne 2a de la galette 2 absorbe par rayonnement une partie substantielle de la chaleur émise par la face amont 6a de la structure 6
• et du côté opposé 2b à la face amont 6a de la structure 6, la galette 2 dissipe et transmet la chaleur reçue par rayonnement, mais aussi par conduction, si une charge thermique est disposée sur la face externe 2b de cette même galette.

The ceramic-ceramic material of the thermal receptor 2, having a coefficient of transmission of thermal radiation, of between 30 and 60%, appears to be particularly well suited to the aim aimed at, namely the cooling of the upstream side of the catalytic burner, because:

• the internal face 2a of the wafer 2 absorbs by radiation a substantial part of the heat emitted by the upstream face 6a of the structure 6
• and on the opposite side 2b to the upstream face 6a of the structure 6, the wafer 2 dissipates and transmits the heat received by radiation, but also by conduction, if a thermal load is placed on the external face 2b of this same wafer.

• le déflecteur 8 est constitué par une paroi isolée thermiquement, en forme de cuve, traversée par le conduit 7 d'arrivée du mélange à brûler, formant carénage de l'appareil de chauffage
• un rebord périphérique 50 est disposé perpendiculairement à la virole interne 12, et prolonge de manière sensiblement coplanaire le récepteur thermique 2 plan ; le rebord périphérique 50, qui peut être continu ou discontinu, se trouve disposé transversalement au parcours des fumées de combustion, pour les défléchir dans une direction horizontale, à la sortie de chaque passage entre deux ailettes consécutives 11 ; ce rebord métallique 50 permet à la fois de protéger la structure catalytique 6 contre l'écoulement vers le bas, de tout débordement d'une casserole, et de transférer vers cette dernière, par conduction, la chaleur extraite et des fumées de combustion et de la chambre de distribution 5.

The device shown in Figures 3 and 4 differs from that described with reference to Figures 1 and 2, by the following technical characteristics:

• the deflector 8 is constituted by a thermally insulated wall, in the form of a tank, crossed by the conduit 7 for the arrival of the mixture to be burned, forming a fairing for the heating appliance
• a peripheral rim 50 is arranged perpendicular to the internal ferrule 12, and extends in a substantially coplanar manner the thermal receiver 2 plane; the peripheral rim 50, which may be continuous or discontinuous, is arranged transversely to the path of the combustion fumes, to deflect them in a horizontal direction, at the outlet of each passage between two consecutive fins 11; this metal rim 50 makes it possible both to protect the catalytic structure 6 against the downward flow, of any overflow of a pan, and to transfer to the latter, by conduction, the heat extracted and combustion fumes and the distribution chamber 5.

• leur partie brûleur est étanche, ce qui permet de le faire fonctionner en toute circonstance, par exemple sous la pluie ou par grand vent
• leur structure catalytique est protégée par la galette 2, contre les "coulures" ou chocs accidentels
• à travers la vitro-céramique, le fonctionnement de la structure catalytique est parfaitement visible et contrôlable par l'utilisateur ; si la structure ne s'allume pas, la face amont reste sombre ; si une prise de feu se produit, elle peut être détectée par l'utilisateur
• un allumage piezo-électrique peut être disposé du côté de la face aval 6b de la structure 6, et de manière non visible de l'utilisateur.

The cooking appliances previously described have multiple advantages:

• their burner part is waterproof, which allows it to operate in all circumstances, for example in the rain or in strong wind
• their catalytic structure is protected by wafer 2, against "run-off" or accidental impact
• through the ceramic glass, the operation of the catalytic structure is perfectly visible and controllable by the user; if the structure does not light up, the upstream face remains dark; if a fire occurs, it can be detected by the user
• a piezoelectric ignition can be arranged on the side of the downstream face 6b of the structure 6, and not visible to the user.

According to another variant of the present invention, the mixture to be burned can be introduced from the side or around the periphery of the catalytic structure, between the latter and the thermal receptor.

Claims (12)

1. Heating apparatus comprising a catalytic burner (1) and a thermal receiver (2) consuming at least one portion of the heat generated by the catalytic burner, the latter comprising a member (3) for ejecting a flow of combustible gas, a member (4) for admixing primary air with the said flow in order to obtain a mixture to be burnt, a chamber (5) for distributing the said mixture, and a catalytic combustion structure (6) traversed by the mixture from its upstream face (6a), in communication with the distribution chamber (5), to its downstream face (6b) removing the combustion exhaust gases, characterised in that, the radiating flameless combustion front (10) being located during operation in the vicinity of the upstream face of the catalytic combustion structure, the thermal receiver (2) is extended facing the upstream face (6a) of the catalytic structure (6) over virtually the entire surface of the latter, so as to receive the thermal energy emitted by the radiating front, and the said receiver is arranged and constructed in order to dissipate, on the side (2b) opposite the upstream face (6a) of the catalytic structure, at least 30% of the thermal energy received by radiation from the radiating front.
2. Apparatus according to Claim 1, characterised in that the thermal receiver (2) is produced from glass-ceramic material.
3. Apparatus according to Claim 1, characterised in that a deflector (8) of the combustion exhaust gases is disposed facing the downstream face (6b) of the catalytic structure (6) in order to expel the said exhaust gases from the side of the upstream zone of the said structure to the exterior of the distribution chamber (5).
4. Apparatus according to Claim 3, characterised in that the deflector (8) is thermally insulated.
5. Apparatus according to Claim 3, characterised in that it comprises means (9) for flow of the combustion exhaust gases expelled from the upstream side of the catalytic structure (6).
6. Apparatus according to Claim 5, characterised in that it comprises means (11) for heat exchange between the interior of the distribution chamber (5) and the combustion exhaust gases expelled from the upstream side of the catalytic structure (6).
7. Apparatus according to Claims 5 and 6, characterised in that the heat-exchange means (11) are fins perpendicular to the wall (12) of the distribution chamber (5) and in thermal contact with the said wall, these fins channelling the flow of the combustion exhaust gases expelled from the upstream side of the catalytic structure (6).
8. Apparatus according to Claim 1, characterised in that a reflector gauze (8) is disposed facing the downstream face (6b) of the catalytic structure (6) in order to reflect the radiation, emitted by the downstream face (6b) of the catalytic structure, to the exterior of the distribution chamber (5).
9. Apparatus according to Claim 1, of the radiant heating type, characterised in that the thermal receiver (2) is arranged and constructed in order to transmit, by conduction and convection, heat from the side (2b) opposite the upstream face (6a) of the catalytic structure (6).
10. Apparatus according to Claim 2, of the cooking hot-plate type, characterised in that the thermal receiver (2) is disposed substantially horizontally for the support of a thermal load.
11. Apparatus according to Claim 10, characterised in that a peripheral rim (50), continuing the thermal receiver (2) in a substantially coplanar manner, is disposed transversely to the course of the combustion exhaust gases in order to deflect them in a horizontal direction.
12. Apparatus according to Claim 1, of the cooking grill type, characterised in that the thermal receiver (2) is arranged and constructed in order to radiate heat from the side (2b) opposite the upstream face (6a) of the catalytic structure (6).

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