| 摘要 |
<p>A tight closing damper, preferably in the shape of a Venetian shutter with lids (5, 6). Arms (3, 4) carrying the lids (5, 6) are designed to permit opening of the damper by turning a shaft (1) at least close to 90o, which shaft is journalled on one side of the damper wall and on which the arms (3, 4) are secured in such a manner that the gas may flow freely through the openings.</p> |
