| 摘要 |
PROBLEM TO BE SOLVED: To recover latent heat of combustion exhaust gas while removing NOx by providing a water atomizing/supplying means in a supply/exhaust air passage on the upstream side of a heat exchanger thereby lowering combustion temperature or combustion exhaust gas temperature. SOLUTION: As a suction fan 36 is operated, outdoor air is introduced to a burner 22 as combustion air. During combustion, an upper solenoid valve 51 is opened and mist water is ejected from an upper nozzle 42 toward a supply fan 36. Combustion temperature of the burner 22 is lowered by that water and generation of NOx and NOx is reduced. Furthermore, NOx is reduced during combustion by hydrogen contained in steam and removed from combustion exhaust gas. Similarly, a lower solenoid valve 53 is opened and mist water is ejected from a lower nozzle 43 toward combustion exhaust gas. That water is ejected toward a region where NOx is generated easily and combustion exhaust gas is cooled when the water robs heat therefrom to produce steam. Consequently, generation of NOx is suppressed and generated NOx is dissolved into the ejected water and removed from combustion exhaust gas. |
