| 摘要 |
PURPOSE:To restrain the drip of a room temperature at a kitchen or the like due to increase of the amount of air passing through a duct in case many gas ranges are used at the same time in summer and the decreasing of the amount of air passing through the duct in case the gas ranges are used in winter by a method wherein fins provided on the duct is controlled by a mechanical dis placement and the amount of a ventilation is controlled. CONSTITUTION:Respective fins 11 are constituted of a shape memory member, whose respective ends are fitted pivotably to respective shafts 13 which are put in horizontal for the frame 12 constituting a shutter section 10. The section thereof becomes straight in high temperature and it bends in low temperature. Accordingly, the ventilating resistance of the shutter section 10 becomes large in case the air passing through the duct 2 is in low temperature, therefore, the amount of the exhaust may be restricted in small value while the ventilating resistance of the shutter section 10 becomes small in case the air passing through the duct 2 is in high temperature, therefore, the amount of exhaust may be increased. |
