JPS61147013A - Catalytic burning equipment - Google Patents

Abstract

PURPOSE:To obtain securely a high radiation heat efficiency by a method wherein a lath net, which is applied flattening by a roller treatment or the like, is provided on a catalyst layer as a protecting net to prevent flowing out an unburnt-gas as well as prevent generating hazard gas of carbon monoxide or the like. CONSTITUTION:A protecting net 7 made of a thin stainless steel, which is processed in a lath shape, produced a flat surface of wire net by a roller treatment and also is integrally constituted, is provided on a catalyst layer 6, thereby a high radiation heat efficiency is securely obtained, because deformation of the wire net is completely eliminated compared with an ordinary plain fabric metal wire net with a deformation trouble, its wire mesh is formed in a rough one. Besides, this is constituted of a protecting net having a property of comparatively small heat capacity, which does not cause a decrease of temperature in the front surface of the catalyst layer 6, maintaining uniformly a suitable temperature for activation of catalysts, similarly, a sufficient amount of air of the secondary air is taken in through the protecting net 7, thereby it is possible to promote an oxidized reaction as well as to prevent leaking out an unburnt methane gas, further, possible to effectively prevent the generation of a hazard carbon monoxide gas, through which a complete combustion is obtainable.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to bringing a combustible gas such as city gas, natural gas, or LP gas into contact with a catalyst to perform an oxidation reaction and heat it.
The present invention relates to a catalytic combustion device configured to perform heating using the heat of reaction.

Conventional technology Conventionally, this type of catalytic combustion device has a gas chamber configured in a burner case, a heat insulation layer and a catalyst layer sequentially stacked on the downstream side.
A protective net such as a plain-woven wire mesh made of stainless steel wire or the like was provided to cover the surface of the catalyst layer.

Problems to be Solved by the Invention However, with the above configuration, the protective net is likely to lose its shape.
．． 3) or a fine wire mesh. For this reason, the protective net, which has a large heat capacity, becomes a heat radiator, resulting in a decrease in temperature on the surface of the catalyst layer, lack of temperature uniformity, and a decrease in combustion efficiency (increase in the amount of unburned gas slipping).

-The amount of carbon oxide generated was increasing. When a finer mesh is used in a radiant heater or the like, the amount of radiation from the catalyst layer is reduced, resulting in a decrease in radiation efficiency. In addition, there have been other problems such as thermal deformation due to heat cycles, which impairs the aesthetic appearance of the device, and generation of squeaks due to thermal deformation.

The present invention aims to solve such conventional problems, and aims to provide a catalytic combustion device that improves combustion efficiency and prevents thermal deformation of a protective net while maintaining high radiation efficiency.

Means for Solving the Problems In order to solve the above problems, the catalytic combustion apparatus of the present invention includes:
As a protective net for the catalyst layer, a lath net that has been flattened by roller processing or the like is provided.

Effects of the present invention With the above-described configuration, the mesh of the protective net can be arbitrarily selected, and the heat capacity of the protective net is small, and the amount of heat dissipated is reduced, thereby preventing a drop in temperature of the catalyst layer and making the temperature uniform. This makes it possible to prevent the outflow of unburned gas (raw gas) and the generation of harmful gases such as -carbon oxide, and to ensure high radiation efficiency. Furthermore, since the protective net is integrally constructed, it does not deform at all, and thermal deformation due to heat cycles and generation of squeaks can be prevented.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings. In FIGS. 1, 2, and 3, 1 is a burner case, and a gas chamber 2 is formed in this burner case 1. On the opening side of the gas chamber 2, a mat support net 3, a heat insulation layer 4, , heater5. A catalyst layer 6° and a protective net 7 are sequentially laminated. The catalyst layer 6 has noble metal elements such as platinum, baradium, and rhodium supported on inorganic heat-resistant fibers. The protective net 7 is made of a thin stainless steel plate (0,5-o,6
The planar portion 9 is formed by rolling a lath net of mm 2 mm) so as to be in planar contact with the outer periphery of the combustion gas passage portion 8.

10 opens the flame opening 11 with a holding metal fitting of the protective net, and protects it so that the lath processing direction of the protective net 7 is parallel to the long side 12 of the flame hole opening 11, that is, the mesh direction is vertical. A net is set up. 13 is a thermocouple for detecting the preheating temperature, 14 is a lead wire of the preheating heater, and 16 is a gas supply section.

In the above configuration, the heater 6 is energized to preheat the catalyst layer 6 before the start of combustion. This preheating temperature (for example, 260 to 300° C. for natural gas) is detected by the thermocouple 13, and fuel gas is supplied into the gas chamber 2 from the fuel gas supply section 14. Next, the combustion gas whose pressure has been equalized in the gas chamber 2 is transferred to the heat insulating layer 4. It flows into the catalyst layer e. At this time, the fuel gas is ignited by the heater 5, and secondary air is supplied from the outside air through the protective net 7 over the entire area of the catalyst layer 6, and after a few minutes, the catalyst layer 6 always reaches a sufficient activation temperature (for example, 400 ~600°C) to maintain steady combustion.

That is, in order to perform clean combustion without leaking unburned components such as methane gas, it is necessary to maintain a sufficient supply of secondary air from the surface of the catalyst layer 6 and a uniform activation temperature of the catalyst layer 6. It is essential.

Therefore, in the catalytic combustion device of the present invention, the protective net for the catalyst layer 6 is made of a planar net that is lath-processed from a thin stainless steel plate material and then subjected to roller processing, etc. Since deformation is completely prevented and the mesh can be made coarse, the amount of radiation from the catalyst layer 6 is not reduced, so high radiation efficiency can be ensured. Furthermore, since the protective net 6 is configured with a relatively small heat capacity, a uniform activation temperature (for example, 400 to soo'C) can be maintained without causing a temperature drop on the surface of the catalyst layer 6, and By obtaining sufficient secondary air, it is possible to promote the oxidation reaction, prevent the leakage (slip) of raw gas such as methane gas, and suppress the generation of harmful gases such as carbon monoxide, thereby achieving complete combustion.

In addition, since the protective net 7 is integrated, the combustion
Even in the heat cycle caused by repeated -OFF cycles, there is no generation of squeaks that occur when the wires of the protective net mutually expand and contract.

Furthermore, since the lath net is formed into a thousand orchid shape by rolling, etc., when a thermal cycle occurs, the protective net 7 can freely expand and contract, suppressing the occurrence of thermal deformation, and at the same time 6 and the catalyst layer 6 are in planar contact with each other, the surface of the catalyst layer 6 can be prevented from being damaged.

Since the protective net 7 is arranged parallel to the lath processing direction with respect to the long side 12 of the rectangular flame opening 11, the rigidity of the protective net 7 is strong and thermal deformation due to thermal cycles is almost non-existent. It has been confirmed through experiments that this does not occur.

Furthermore, by constructing the protective net 7 from a thin stainless steel plate material with low thermal conductivity, heat conduction to the outer periphery of the flame opening 11 is suppressed, promoting the maintenance of high temperature of the protective net and preventing a drop in the temperature of the catalyst layer. This has the effect of further improving combustibility as described above.

Effects of the Invention As described above, in the catalytic combustion device of the present invention, the following effects can be obtained by arranging lath steel made flat by rolling or the like as a protective net for the catalyst layer.

(1) Clean combustion can be achieved by suppressing the leakage (slip) of unburned gas such as methane and the generation of harmful gases such as -carbon oxide.

(2) It is possible to completely prevent the protective net from deforming, and also to prevent thermal deformation and generation of squeaks due to thermal cycles.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a catalytic combustion device according to an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, FIG. 3 is a plan view of the protective net shown in FIG. 1, and FIG. Figure shows a side view. 6...Catalyst layer, 7...protective net, 11...
...flame mouth opening. Name of agent: Patent attorney Toshio Nakao and one other person fs
Figure 1 Figure 2

Claims (3)

[Claims] (1) A catalytic combustion device configured to cause combustible gas to oxidize and burn in a catalyst layer, and in which lath steel with a flat surface finish is provided as a protective net for the catalyst layer. (2) The catalytic combustion device according to claim 1, further comprising a protective net whose lath processing direction is parallel to the long side of the rectangular flame opening. (3) The catalytic combustion device according to claim 1, wherein the lath mesh is made of a thin stainless steel plate material.