| 摘要 |
Across the gas flow path in a duct such as for air conditioning there is placed a composite filter set comprising a plurality of filter elements and means joining said elements, each of said filter elements comprising a plurality of filter pockets and a frame holding said pockets at their open ends, and said joining means connecting the frames of adjacent filter elements in a manner to form a gas-tight seal therebetween so that flowing gas can advance only by passage through one of said filter pockets. |
