| 摘要 |
Inner cases (4, 20, 31) are connected to outer cases (5, 21, 32) through connection flanges (25, 26, 40, 41) which project out of the outer peripheral sides of the outer cases (5, 21, 32). A plurality of combinations, each consisting of filters (2, 3), the inner cases (4, 20, 31), and the outer cases (5, 21, 32) are provided. The plurality of outer cases (5, 21, 32) are connected to each other by holding and securing both of the connection flanges (25, 26) (40, 41) by and between a pair of holding flanges (51, 52) (53, 54). |
