JPH0141887B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a catalytic combustor for burning gaseous fuel in the presence of a catalyst.

BACKGROUND ART Generally, combustion in a catalytic combustor is started by heating the catalyst layer to a temperature higher than the combustion limit temperature and supplying fuel gas to the heated catalyst layer. Conventional heating methods include heating the entire catalyst layer by burning fuel gas on the surface of the catalyst layer in a normal flame state, heating a part of the catalyst layer using a separate electric heater, etc. measures were taken.

Problems to be Solved by the Invention However, the former of these means burns the fuel gas flamingly, reducing its value as a catalytic combustor by half, and heating the entire catalyst layer. It was common for it to take a long time. In addition, the latter heating means does not heat the entire catalyst layer, does not generate flame, and can use a dry battery or the like as a power source for the ignition heater. However, when there is little fuel gas or when the fuel gas is dilute, simply touching a part of the main catalyst layer with the ignition heater will take a long time until catalytic combustion starts, and reliable ignition cannot be expected. Nakatsuta.

The present invention eliminates the above conventional problems and provides a catalytic combustor that can reliably ignite in a short time.

Means for Solving the Problems In order to achieve the above object, the catalytic combustor of the present invention provides a main catalyst layer on the outer periphery of a cylindrical porous support material whose downstream end is closed, and In this structure, an ignition catalyst layer is provided in contact with one end of the downstream side of the layer and the support material to block the flow path of fuel gas, and an ignition heater is further provided in contact with the ignition catalyst layer.

Effect According to the above configuration, fuel gas passes through the main catalyst layer and around the ignition catalyst layer, but the amount of gas per unit area of the ignition catalyst layer that is in contact with only one end on the downstream side is Because it is larger than the amount of gas in the main catalyst layer,
It quickly reaches the combustible temperature.

Embodiments The embodiments will be described below with reference to the accompanying drawings.
The structure of the catalyst layer is such that a heat-resistant transparent material such as glass fiber, alumina, or cordierite is used as a carrier, and a catalyst such as platinum, palladium, etc. is attached thereto.

In the figure, a fuel gas outlet 2 protrudes from one closed end of a cylindrical metal case 1. The tip of the jet nozzle 2 is inserted into a cylindrical support member 3 whose outer periphery is covered with a main catalyst layer 4 . This supporting material 3 is sealed at its downstream end, and has holes penetrating its outer periphery that become smaller in diameter toward the downstream side, so that fuel gas is uniformly supplied to the main catalyst layer 4. . Reference numeral 5 denotes a disk-shaped ignition catalyst layer, which is provided so as to be in contact with the downstream ends of the main catalyst layer 4 and the support material 3 and to cross the fuel gas passage. The ignition heater 6 is attached in contact with the periphery of the ignition catalyst layer 5.

In the above embodiment, the fuel gas supply tank is opened at the same time as voltage is applied to the ignition heater 6. Then, the fuel gas passes through the main catalyst layer 4 and around the ignition catalyst layer 5. The amount of gas per unit area of the ignition catalyst layer 5 is considerably larger than the gas passing through the unit area of the main catalyst layer 4. Here, the ignition catalyst layer 5 is heated to 150 to 350°C, and quickly reaches the combustible temperature. At this time, the fuel gas starts to burn quickly in the ignition catalyst layer 5, and the temperature increase in the ignition catalyst layer 5 is transmitted to the main catalyst layer 4 through the support material 3 or directly. is heated to 150-350℃ to reach the combustible temperature. However, 90% of the fuel gas is in the main catalyst layer 4.
Start combustion. Therefore, until combustion starts in the main catalyst layer 4, the ignition catalyst layer 5 is hit with the fuel gas intensively, so that ignition is easily started and at the same time the temperature is temporarily raised to 600 to 800°C. However, once combustion starts in the main catalyst layer 4, there is almost no combustion in the ignition catalyst layer 5, and the life of the ignition catalyst layer 5 is ensured. In addition, the time required for combustion to start in the ignition catalyst layer 5 is short, and combustion continues in the ignition catalyst layer 5 until complete combustion occurs in the main catalyst layer 4, so the outflow of raw gas is extremely small and safety is high. be.

Effects of the Invention As described above, according to the present invention, the catalytic combustor can be ignited reliably and safely in an extremely short period of time.

[Brief explanation of drawings]

FIG. 1 is a side cross-sectional view of a catalytic combustor showing one embodiment of the present invention, and FIG. 2 is a front cross-sectional view taken along the line AA in FIG. 3...Supporting material, 4...Main catalyst layer, 5...Ignition catalyst layer, 6...Ignition heater.

Claims (1)

[Claims] 1. A main catalyst layer is provided on the outer periphery of a cylindrical porous support material with one downstream end sealed, and the main catalyst layer is ignited so as to contact the main catalyst layer and one downstream end of the support material to block the fuel gas flow path. A catalytic combustor, comprising: a catalyst layer for ignition; and an ignition heater provided in contact with the catalyst layer for ignition.