| 摘要 |
PURPOSE:To keep air capacity between respective suction ports constant even when calorific value is changed in an exhaust duct for exhausting the heat of a heating element whose calorific value is changed. CONSTITUTION:A duct 1 having one end which is closed and the other end where a suction fan 3 is provided, plural suction ports 2a to 2d provided on a surface opposed to the heating element whose calorific value is changed, a shutter 8 adjusting the area of the aperture of the suction ports 2c and 2d adjacent to the suction fan, a control means 5 adjusting the sucking ability of the fan 3 and the area of the aperture of the suction ports 2c and 2d in accordance with the calorific value of the heating element are installed in the exhaust duct for exhausting the heat of the heating element whose calorific value is changed. |
