JPH06147419A - Apparatus for catalytic combustion - Google Patents

Abstract

PURPOSE:To realize high load of combustion chamber by preventing catalyst used in an apparatus for catalytic combustion from being thermally deteriorated as well as keeping combustion characteristics in good conditions, the apparatus being used to make gas or liquid fuel to effect catalytic combustion in order to perform heating, room heating, drying, etc. CONSTITUTION:The title apparatus is provided with a radiant plate 11 having both an inside face lined with radiant absorber layer 13 and an outside face composed of fins 12, the radiant plate 11 being opposed to the upper stream face of catalyst 8. Combustion heat generated by the catalytic combustion is absorbed by the radiant plate 11, and the absorbed heat is radiated by natural convection occurring above the fins 12 provided on the outside face of the radiant plate 11 so as to suppress the temperature rise in the catalyst 8 in a high combustion intensity zone; therefore, the catalyst is prevented from being thermally deteriorated and high load of combustion chamber is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic combustion apparatus for catalytically burning a gaseous fuel or a liquid fuel for heating, heating, drying, etc., and particularly to a catalytic combustion apparatus excellent in exhaust gas purification characteristics.

[0002]

2. Description of the Related Art Conventionally, a catalytic combustion apparatus for catalytically burning a gas fuel or a liquid fuel for heating, heating, drying, etc. has generally been constructed as shown in the sectional view of FIG.

In FIG. 2, fuel is supplied from a fuel tank 1 to a premix chamber 4 heated by a heater (not shown) by a fuel pump 2 and vaporized into fuel gas. The air is supplied to the premixing chamber 4 by the air supply fan 3, mixed with the fuel gas, and sent to the preheating burner 5. It is ignited by the ignition device 6 to form a flame.

The high-temperature gas produced by this flame passes while heating the catalyst 8 in the combustion chamber 7 and is discharged from the exhaust port 9. When the temperature at which the catalyst 8 shows activity is reached, the fuel supply is stopped and the flame is extinguished. Then, the fuel is immediately supplied and the premixed gas is directly sent to the catalyst 8 to start the catalytic combustion. By carrying out catalytic combustion, the catalyst 8 is brought into a high temperature state and is radiated to radiate heat from the glass plate 10 and, at the same time, exhaust hot exhaust gas from the exhaust port 9.

[0005]

In such a conventional catalytic combustion apparatus, a gas premixed with fuel and air undergoes an oxidation reaction in the catalyst to generate carbon dioxide and water together with the heat of reaction. The reaction heat at this time can be used to perform heating, heating, and drying, but it is necessary to change the amount of combustion depending on the object and the usage environment.

Further, in order to be usable in a closed space such as a room, the characteristics of exhaust gas must be good. Therefore, a convenient catalytic combustion device must be capable of widely changing from a low combustion amount region to a high combustion amount region in a clean combustion state. But,
In a region where the amount of combustion is large, the temperature of the catalyst rises excessively, exceeds the heat resistance limit, and thermal degradation of the catalyst is likely to occur. As described above, in the conventional catalytic combustion apparatus, if the catalyst is burned so as to suppress the thermal deterioration and the exhaust gas is kept in a clean state, there is a problem that the combustion cannot be performed in a high combustion amount region.

The present invention solves the above problems, and an object of the present invention is to avoid thermal deterioration of the catalyst and obtain a high combustion load while maintaining the exhaust gas in a clean state.

[0008]

In order to achieve the above object, the catalytic combustion apparatus of the present invention comprises an inner surface coated with a radiation absorbing layer and a fin at a position facing the upstream surface of the catalyst. A heat sink having an outer surface is installed.

[0009]

According to the present invention, the combustion heat generated by the catalytic combustion is provided by providing the heat dissipation plate having the inner surface covered with the radiation absorption layer and the outer surface constituted by the fins at the position facing the upstream surface of the catalyst. Is absorbed by the heat radiating plate and is radiated by natural convection generated on the fins on the outer surface of the heat radiating plate, the temperature of the catalyst in the high combustion amount region is suppressed, and a high combustion load is realized while preventing thermal deterioration.

[0010]

1 is a sectional view showing the structure of a catalytic combustion apparatus according to an embodiment of the present invention. In FIG. 1, 11 is a heat radiating plate, which is provided on the opposite side to the upstream side of the catalyst 8. The heat dissipation plate 11 has fins 12 on the outer surface, and the inner surface is covered with a radiation absorbing layer 13. In addition, the same components as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.

In the above structure, the fuel is the fuel tank 1.
Is supplied from a fuel pump 2 to a premix chamber 4 heated by a heater (not shown), and vaporized into a fuel gas. The air is supplied to the premixing chamber 4 by the air supply fan 3, mixed with the fuel gas, and sent to the preheating burner 5. Ignition device 6
Is ignited by and forms a flame. The high-temperature gas generated by this flame passes through the combustion chamber 7 while heating the catalyst 8, and is discharged from the exhaust port 9. When the temperature at which the catalyst 8 shows activity is reached, the fuel supply is stopped and the flame is extinguished. Thereafter, the fuel is immediately supplied, and the premixed gas is directly sent to the catalyst 8 for catalytic combustion.

In the present invention, in the conventional heater, the glass plate 10 shown in FIG. 2 which is provided at a position facing the upstream surface of the catalyst 8 is replaced with the heat radiating plate 11, so that the heat radiating plate is radiated by the catalyst 8. 11 becomes hot and the fins 12 on the outer surface of the heat sink 11
Natural convection is generated above and the heat of the heat dissipation plate 11 is dissipated. Since the inner surface is covered with the radiation absorbing layer 13, the temperature of the heat radiating plate 11 is lowered, so that the heat radiating plate 11 further deprives the radiant heat emitted from the catalyst 8 to lower the temperature of the catalyst 8. Therefore, thermal deterioration of the catalyst 8 can be avoided, and good combustion characteristics can be maintained even in a high combustion amount region.
A high combustion load can be realized.

If the outer surface of the heat radiating plate 11 is covered with a radiation absorbing layer, not only the heat radiating effect from the heat radiating plate 11 depends on natural convection but also heat radiation by radiation can be expected.

Further, the radiation absorbing layer may be a paint or sheet which easily absorbs radiation, or a metal oxide such as rust.

Although the liquid fuel has been described above, the same effect can be obtained with a gas fuel.

[0016]

As described above, in the catalytic combustion apparatus of the present invention, a radiator plate having a radiation absorbing layer on the inner surface and a fin on the outer surface is installed at a position facing the upstream surface of the catalyst. As a result, the radiation from the catalyst can be cooled by the radiator plate, and the temperature rise of the catalyst can be suppressed.

As described above, a region where good combustion characteristics can be maintained without causing thermal deterioration can be widely realized up to a high combustion amount region, and it can be used not only as a heat source for heating and drying but also for a multipurpose use. Is possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a catalytic combustion device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a conventional catalytic combustion device.

[Explanation of symbols]

8 ... Catalyst, 11 ... Heat sink, 12 ... Fin, 13 ... Radiation absorption layer.

Claims (1)

[Claims] 1. A premixing chamber for mixing fuel and air, a combustion chamber installed downstream of the premixing chamber, a catalyst having a large number of communication holes installed in the combustion chamber, and an upstream surface of the catalyst. A catalytic combustion device comprising: a heat dissipation plate installed at a position facing each other, the heat dissipation plate having an inner surface covered with a radiation absorption layer and an outer surface constituted by fins.