| 摘要 |
PURPOSE: To lower the temperature of the flame so as to reduce NOX from the combustion by combining surface combustion using a metallic fiber-sintered mat with heating of premixed fuel gas using an exhaust-gas heat exchanger. CONSTITUTION: As regards a heat exchanger 3 metal fiber-sintered mat 3d is partitioned off by a partition 3c into a first region 3a for premixed fuel gas to flow through and a second region 3b for the exhaust gas from combustion to flow through. Integrally on the downstream side of the first region 3a a burner part 2 is formed with the surface part of the first region 3a as a combustion area 2a. The exhaust gas, after passage through the second region 3b, is partly incorporated with a flow of premixed fuel gas by the action of a blower 9 and carried though the first region 3a of the heat exchanger part. In the first region 3a, with heat energy transferred from the metallic fiber formed in a fiber mat, the premixed fuel gas is heated to a high temperature and then burns at the combustion area 2a, which is the downstream surface part of the first region 3a. The fuel fed for this combustion is limited to an amount necessary for making the surface of the metallic fiber-sintered mat red-hot and for the evolution of adequate radiant heat. Therefore, the temperature of the flame can be made low and NOX in the exhaust gas can be reduced. |
