| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress NOx generation amount to a low value and to stably burn by providing an exhaust gas recirculation special purpose fan for forcibly recirculating exhaust gas to an exhaust gas recirculation passage, and providing a bypass passage between the recirculation passage and the combustion air passage of a burner body. SOLUTION: An exhaust gas recirculation special purpose fan 11 for recirculating exhaust gas is provided at the exhaust gas recirculation passage 7 of the side of an exhaust gas box 8, and a bypass passage 12 for coupling a combustion air passage 4 to the passage 7 is provided at the passage 7 of an exhaust gas recirculation box 7b side. The number of revolutions of the fan 11 is controlled to control the recirculation amount of the exhaust gas to a predetermined quantity, stably maintained at the temperature for attempting to sufficiently lower the NOx, thereby making it possible to suppress the NOx generation amount to a low value. At the time of starting the operation, the fresh combustion air is reversely fed to the passage 7 via the passage 12 to prevent the condensation of the inner surface of te passage 7 system.</p> |
