WO2009105907A1

WO2009105907A1 - Catalytic radiating heating appliance

Info

Publication number: WO2009105907A1
Application number: PCT/CH2009/000076
Authority: WO
Inventors: Claudio Fassio; Renato F. MÜLLER
Original assignee: Radiamon S.A.
Priority date: 2008-02-27
Filing date: 2009-02-25
Publication date: 2009-09-03
Also published as: EP2245368A1

Abstract

The invention relates to a catalytic radiating heating appliance that comprises at least one catalytic cell (11) including a catalytic combustion chamber (15) associated with a gas diffuser (16) supplied by an external supply source and adapted for diffusing a fuel gas on a catalyst (17a) on which is arranged a diffusion structure (17b) adapted for ensuring a substantially homogenous distribution of said fuel gas. The catalyst (17a) is adapted for oxidising hydrogen injected into the catalytic combustion chamber (15) and diffused by the gas diffuser (16). The appliance further includes a means (22) for controlling and monitoring the gas supply, a means (23) for controlling the inner temperature of the catalytic combustion chamber (15), and a means for generating a thermal radiation.

Description

RADIANT HEATING APPARATUS OF THE CATALYTIC TYPE

Technical area

The present invention relates to a radiant heater of the catalytic type using a fuel gas, comprising at least one catalytic cell which comprises a catalytic combustion chamber, a diffuser of said fuel gas which opens into said catalytic combustion chamber and a catalytic combustion device mounted in said catalytic combustion chamber and arranged to oxidize said injected gas in the catalytic combustion chamber and generate a thermal radiation.

Prior art

Catalytic type gas heaters are already known which use town gas or natural gas as fuel. These devices have the disadvantage of requiring, on the one hand, a prior desulfurization of the gas and, on the other hand, preheating and ventilation. As a result, these heaters become heavy and bulky and their cost increases accordingly. In addition, in use they produce gaseous emissions, including carbon dioxide (CO2) which is sought by all means to limit production. They do not fall into the category of so-called clean heaters.

GB 2 249 491 discloses in particular a catalytic heating element comprising at least two catalytic cells having different operating and ignition gas temperatures, that is to say a main catalytic cell and at least one cell. secondary catalytic. The secondary catalytic cell or cells serve to preheat the main cell.

Publication US 2003/129557 relates to a process for preheating the catalyst of a catalytic element in which a mixture of hydrogen and nitrogen is used to preheat a catalyst operating with natural gas or propane. Japanese Abstract JP 61 147014 relates to a catalytic burner provided with a thermocouple arranged to detect the preheating temperature of a catalyst comprising three layers having different oxidizing capacities.

Japanese Abstract JP 60 233413 discloses a catalytic combustion device comprising two juxtaposed catalytic cells respectively contain two different catalysts.

The patent FR 1 122 565 relates to a process for the catalysis of hydrocarbons that can be used in a heating apparatus in which the embodiment described in its general principle comprises a gas supply pipe coupled by a tap to a device for adjusting the temperature. hydrocarbon gas mixture - air bound to a vaporization chamber.

Presentation of the invention

The present invention proposes to overcome the disadvantages of known apparatuses by providing a radiant catalytic heater that does not require a preheating cell, which is light, compact, economical to purchase and use and which, moreover , meets the current requirements for environmental protection by burning that does not produce carbon dioxide.

For this purpose, the heating apparatus according to the invention, as defined in the preamble, is characterized in that said combustible gas is hydrogen gas, and in that said catalytic combustion device comprises a diffusion structure of said fuel gas combined with a catalyst comprising at least one treated element of a catalyst material, said diffusion structure of said fuel gas being arranged to distribute said fuel gas homogeneously on said catalyst. According to a preferred embodiment, said diffusion structure comprises at least one porous sieve arranged to ensure a substantially homogeneous distribution of said fuel gas, said porous sieve comprising at least one layer of fibers resistant to high temperatures.

Advantageously, the apparatus according to the invention further comprises means arranged to automatically control the engagement and / or tripping of said heating apparatus as a function of the ambient temperature, said means comprising both means arranged to controlling and controlling the supply of fuel gas and means arranged to control the internal temperature of the catalytic combustion chamber.

According to an alternative embodiment, said catalyst may consist of at least two superposed layers of catalyst material.

Preferably, the diffusion structure of the catalytic combustion device is directly juxtaposed to said catalyst.

In the preferred embodiment of the apparatus, the catalytic cell is closed by an inner cover substantially parallel to an external cover and disposed below the latter, said inner cover being mounted on peripheral side walls of a box which is closed by the outer cover and by an external grid.

Advantageously, the fuel gas diffuser is connected to a supply pipe coupled to the output of a control valve whose input is connected to a calibrated injector.

Preferably, said means arranged to control and control the supply of the apparatus with hydrogen gas may comprise an autonomous module for controlling and controlling the supply of hydrogen gas carried by a support disposed in the catalytic cell, and said means arranged for control the internal temperature of the catalytic combustion chamber may comprise a thermal probe connected to said autonomous module for controlling and controlling the supply of hydrogen gas.

Brief description of the drawings

The present invention and its advantages will be better understood on reading the detailed description of an advantageous embodiment of the invention, with reference to the accompanying drawings given by way of non-limiting indication, in which:

FIG. 1 is a perspective view, partly in section, showing the heating apparatus according to the invention,

FIG. 2 represents a cross-sectional view of the catalytic cell of the heating apparatus of FIG. 1,

FIGS. 3A, 3B and 3C show detail views illustrating components of the catalytic cell of FIG. 2, and

Figure 4 is an operating diagram of the heater according to the invention.

Best way to realize the invention

With reference to FIGS. 1 and 2, the heating apparatus 10 as exemplified mainly comprises a catalytic cell 11 mounted inside a box 12 closed on the top by an outer cover 13 and below. by an external grid 14 and provided with peripheral side walls 12a folded sheet metal or made by means of metal profiles. The catalytic cell 11, which is the active element of the apparatus, mainly comprises a catalytic combustion chamber 15, a combustible gas diffuser 16 housed in this chamber and a catalytic combustion device 17. This catalytic combustion device 17 is composed of at least one catalyst 17a comprising at least one treated element of a catalyst material and at least one diffusion structure 17b of the fuel gas. The diffusion structure 17b is preferably directly juxtaposed with the catalyst 17a and has the function of diffusing the fuel gas homogeneously on said catalyst. This diffusion structure 17b, which is held in position on the catalyst 17a by a grid 17c, advantageously consists of a porous sieve which preferably comprises at least one layer of fibers arranged to withstand high temperatures, of the order a few hundred degrees. The constituent fibers of the sieve may be ceramic fibers or the like. They are for example assembled according to a needling technique, well known in the field of producing felts based on textile fibers.

The catalytic combustion device 17 is housed in a profiled structure 18, linked to an element 18b integral with a support 18c on which is disposed a control and control module 22, whose function will be defined below, and which is connected a thermal probe 23, housed in the catalytic combustion chamber 15.

A calibrated injector 20 is connected to a control valve 21 which is coupled to the fuel gas diffuser 16. This fuel gas diffuser 16 advantageously comprises a tubular part having a certain number of openings which make it possible to substantially uniformly distribute the main flow of fuel. arrival of the fuel gas into a plurality of secondary streams. Other constructions having the same functions could be realized.

The support 18c also carries a supply pipe 24, connected to the control valve 21 and connected to the fuel gas diffuser 16, to supply it with hydrogen. This assembly is mounted on an angle profile 18d which is fixed to the peripheral side walls 12a of the box 12.

The catalytic cell 11 is further closed by an inner cover 19 substantially parallel to the outer cover 13 and disposed under the latter. This inner cover 19 is preferably mounted on the peripheral side walls 12a.

The apparatus 10 is a dihydrogen (H2) oxidizing heater, the fuel gas being supplied from an external source of dihydrogen under pressure (not shown). The supply of hydrogen is through the calibrated injector 20 and the control valve 21 whose output is coupled to the fuel gas diffuser 16. This combustible gas diffuser 16 directs the hydrogen to the catalytic combustion device which comprises the homogeneous diffusion structure 17b and the catalyst 17a where its catalytic oxidation occurs. This oxidation which is carried out on the catalyst 17a is at the origin of the infrared heat radiation of the heating apparatus and the only "waste" produced by this combustion is a release of water vapor (H2O).

FIG. 3A shows a partial cross-sectional view of the catalytic cell 11, illustrating in particular the catalyst 17a which is carried by the angle-shaped profile 18d (see FIG. 2), the homogeneous diffusion structure 17b, the tubing of FIG. supplied 24 of the hydrogen to the gas diffuser 16, and the thermal probe 23.

Figure 3B shows a plan view of the outer gate 14 which consists of a wide open mesh to protect the catalytic combustion chamber 15, and in particular the catalyst 17a, and to pass the infrared radiation.

FIG. 3C represents a plan view of the support 18c which closes the catalytic combustion chamber 15. This support 18c comprises two openings 23a and 24a arranged for the passage respectively of the thermal probe 23 and that of the tubing 24. This support is advantageously realized by means of a metal sheet. Figure 4 is an operating diagram of the apparatus 10 described above. If the device records an external heat demand Ph1, it generates an activation of the power supply 30 of the device and more specifically a Ph2 activation of the control and control module 22 of the device. The command and control module 22 performs a first check which consists of determining whether the time t is YES or NO less than the start time to the device. In case of an affirmative response, the opening phase Ph3 of the gas control valve 21 is activated and the gas diffuser is energized. In the case of a negative response, a second check is made to determine whether YES or NO the temperature T is greater than the temperature To. If the answer is yes, the gas control valve 21 is engaged. In the event of a negative response, a fault command Ph4 is transmitted to the command and control module 22 of the device. When the gas control valve 21 is open, a verification of the internal temperature is performed by the thermal probe 23, for example a thermocouple, which transmits a signal intended, if necessary, to stop the gas supply.

The described heater is not strictly limited to the embodiment described and shown, but could be constructed in a variety of ways. In particular, it could comprise several individual catalytic cells, their shape and their disposition could be varied according to the needs of the application. In addition, the entire support structure of the components could be performed differently. All these variants, however, remain within the scope of the present invention and do not fall outside the field of competence of those skilled in the art.

Claims

A radiant heater of the catalytic type (10) using a fuel gas, comprising at least one catalytic cell (11) which comprises a catalytic combustion chamber (15), a diffuser (16) of said fuel gas which opens into said chamber catalytic combustion device (15) and a catalytic combustion device (17) mounted in said catalytic combustion chamber and arranged to oxidize said injected gas in the catalytic combustion chamber (15) and generate thermal radiation, characterized in that said gas fuel is hydrogen gas, and in that said catalytic combustion device (17) comprises a diffusion structure (17b) of said fuel gas combined with a catalyst (17a) comprising at least one treated element of a catalyst material, said diffusion structure (17b) of said fuel gas being arranged to distribute said fuel gas homogeneously on said catalyst (17a).

2. Heating apparatus according to claim 1, characterized in that said diffusion structure (17b) comprises at least one porous sieve arranged to ensure a substantially homogeneous distribution of said fuel gas, said porous sieve having at least one layer of fibers resistant to high temperatures.

3. Heating apparatus according to claim 1, characterized in that it further comprises means arranged to automatically control the engagement and / or tripping of said heating apparatus as a function of the ambient temperature, and in that said means comprise both means arranged to control and control the supply of fuel gas and means arranged to control the internal temperature of the catalytic combustion chamber (15).

4. Heating apparatus according to claim 1, characterized in that said catalyst (17a) consists of at least two superimposed layers of catalyst material.

5. Heating apparatus according to claim 1, characterized in that said diffusion structure (17b) is directly juxtaposed to said catalyst (17a).

6. Heating apparatus according to claim 1, characterized in that the catalytic cell (11) is closed by an inner cover (19) substantially parallel to an outer cover (13) and disposed below the latter.

Heating apparatus according to claim 6, characterized in that the inner cover (19) is mounted on peripheral side walls (12a) of a box (12) which is closed by the outer cover (13) and by a external grid (14).

8. Heating apparatus according to claim 1, characterized in that said combustible gas diffuser (16) is connected to a supply pipe (24) coupled to the outlet of a control valve (21) whose inlet is linked to a calibrated injector (20).

9. Heating apparatus according to claim 3, characterized in that said means arranged to control and control the supply of hydrogen gas comprises an autonomous control module and control (22) of the supply of hydrogen gas carried by a support (18c) disposed in the catalytic cell (11).

10. Heating apparatus according to claim 3, characterized in that said means arranged to control the internal temperature of the catalytic combustion chamber (15) comprise a thermal probe (23), connected to said autonomous control and control module (22). ) of the hydrogen gas supply.