PURPOSE: To prevent unnecessary increase of a catalyst temperature through simple constitution, by providing a feed means to feed mixture with exhaust gas through the introduction of the open air.
CONSTITUTION: An exhaust gas disposing device 20 is provided with a deodorizing catalyst 23 formed in a honeycomb shape and a heater 21 for heating for heating the deodorizing catalyst. In the exhaust gas disposing device 20, an open air inflow duct 30, connected to the outside, of an exhaust gas system is disposed on the upper stream side of the deodorizing catalyst 23. In the open air inflow duct 30, a damper 24 for shutting and releasing a passage is provided, and is capable of properly controlling switching by means of a control means. When there is a need to decrease the temperature of the deodorizing catalyst 23, a damper 24 is brought into a state to release a duct to introduce the open air, which serves to cool the deodorizing catalyst 23. The open air inflow duct 30 and the damper 24 form a cooling means.
MATSUI KOICHI
KUBO TORU
