| 摘要 |
PROBLEM TO BE SOLVED: To reduce an amount of nitrogen dioxide contained in hot air blown out of a hot air heater. SOLUTION: It is well known that if combustion gas of high temperature is rapidly cooled, an amount of inclusion of nitrogen dioxide is increased. Further, it is also known that if a temperature of combustion gas is high, an amount of occurrence of nitrogen dioxide being a raw material for nitrogen dioxide is increased. In view of this face, air is gradually taken through a back surface 5a and a slant segment 5b of a partition wall cover 5 covering an outlet 23 of a combustion cover 22 so as to perform a gradual cooling of combustion gas and at the same time the air is passed through the front surface part 5c, thereby the combustion gas is cooled at the front surface part 5c. |
