| 摘要 |
PURPOSE:To enable to operate a slide damper always smoothly, by forming bellows around screw shafts for moving a damper blade upward and downward, and thereby preventing sticking of sand or the like to the screw shafts and rusting of the same due to exposure to rain and wind. CONSTITUTION:A blade supporting frame 2 is shaped substantially in the same form as the outer configuration of a duct, and a damper blade 3 moved upward and downward along the support frame 2 is disposed in the duct hermetically in the manner that it is located perpendicularly to the gas flow through the duct. Further, bellows 30 are formed around screw shafts 8a, 8b for protecting them against wind, rain, sand, etc. With such an arrangement, the screw shafts can be protected against rusting or other trouble, so that it is enabled to obtain a slide damper which is operated always smoothly. |
