| 摘要 |
PROBLEM TO BE SOLVED: To reduce the content of nitrogen dioxide contained in the warm air supplied from a warm air heater out of the heater. SOLUTION: It is known that, when high-temperature combustion gas is abruptly cooled, the content of nitrogen dioxide is increased. Therefore, the outlet 23 of a combustion cover 22 mounted at a burner 21 to delay the combustion reaction of a flame is covered with a partition wall 5 to prevent the cold air in a combustion case 2 from being brought into contact with the high- temperature combustion gas exhausted from the outlet 23 at once. Further, an opening 21 is opened at the wall 5 along the flowing direction of the combustion gas, and the air to be introduced into the inside of the wall 5 via an opening 51 is gradually mixed with the combustion gas to gradually cool the combustion gas. |
