摘要 |
PURPOSE:To stabilize ignition and flame in a precombustion chamber and to reduce an amount of nitrogen oxide in exhaust gas and soot dust, by a method wherein a heating means to heat primary air to a temperature higher than a specified temperature is disposed in the middle of a primary air duct through which primary air is guided. CONSTITUTION:A propane combustion chamber 10 is situated in the middle of a primary air duct 9 through which primary air 13 is guided. In the propane combustion chamber 10, propane gas 12 is burnt by means of a propane burner 11, and the primary air 13 is heated to 400 deg.C or more through a combustion reaction heat. In this case, a part of the primary air 13 bypasses through a primary air bypass duct 16 with a damper 17, and is mixed with the propane 12 to form a premixture flame 15. The high temperature primary air heated to 400 deg.C or more is fed through an air resistor 14 to a precombustion chamber 5. |