| 摘要 |
PURPOSE:To suppress the slip ratio in the entire combustion catalyst to the minimum by providing a second combustion catalyst having an oxidizing catalyst carrying ratio which is higher than that of a first combustion catalyst, on the outer peripheral portion of the first combustion catalyst having a predetermined oxidizing catalyst carrying ratio. CONSTITUTION:Power is fed to a preheater 6 and generated heat is transmitted to a first combustion catalyst 7, a second combustion catalyst 9 and a heat insulating diffusion material 5. The combustion gas is ejected into a gas chamber 4 and reaches the catalysts 7 and 8 while being heated to a certain degree to start catalytic combustion. Since the catalyst 9 undergoes a cooling effect through the contact with the burner case 1, the fuel slip ratio becomes about 3% in five minutes immediately after the ignition. However, thereafter the reactivity in the catalyst 7 becomes stable and the oxidizing catalyst carrying ratio of the catalyst 9 is larger than that of the catalyst 7. Therefore, it is possible to keep the catalytic probability between the oxidizing catalyst particles and the fuel gas molecules at a high value. Large reaction heat is produced in the catalyst 9 and the unburnt gas discharged from the entire catalytic burner can be suppressed at its slip ratio to 0.1% or less in the normal conditions.
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