| 摘要 |
<p>PURPOSE:To prevent generation of drain due to exhaust gas by heating an exhaust gas circulation passage by heating means and forming an air intake port near an exhaust gas extraction port. CONSTITUTION:An upper part of an exhaust gas circulation passage 3 is disposed along a heat exchanger 12 to be heated by combustion flame. Thus, exhaust gas H in the passage receives heat to maintain at a high temperature thereby to prevent condensation of steam in the exhaust gas. Further, an air intake port 31 for intaking the air is formed near an exhaust gas extraction port 132 of the passage 3, and an air inlet tube 133 is connected to the port 31. Thus, since the gas H extracted from the port 132 and combustion air intaken from the port 31 are mixed in the passage 3, a ratio of steam in the exhaust gas can be reduced.</p> |
