| 摘要 |
<P>PROBLEM TO BE SOLVED: To easily detect whether a fan filter unit in a clean room used in a semiconductor manufacturing factory and a hospital rotates forward or reversely. <P>SOLUTION: The direction of exhaust air of a fan of the fan filter unit (referred to as FFU hereinafter) is changed depending on forward rotation and reverse rotation, and a plurality of suction ports for sucking air from the outside by the fan when rotating forward are arranged in an upper part of a FFU main body. When the fan rotates reversely, an opening and closing plate is operated by its exhaust air stream to close the suction ports, and the exhaust air stream is forcedly focused to pass a flute arranged in the vicinity of the suction port and exhausted to the outside. Consequently, reverse rotation can be detected by sounding of the flute. <P>COPYRIGHT: (C)2004,JPO |
