| 摘要 |
A filter (2) comprises a filter case (3), the interior of which is divided by a separator (27) into upper and lower filtration chambers (4, 5). A compact filter material (7) of a cylindrical shape is disposed in said upper filtration chamber (4) so as to define on both outer and inner sides thereof a non-purification chamber (37) communicating with upper suction ports (10) formed at the upper part of said filter case and a purification chamber (33) communicating with a drain pipe (9) disposed on the upper surface of said filter case and having a large capacity. A coarse filter material housed in said lower filtration chamber serves also as a weight, said lower filtration chamber communicating with said purification chamber through passage ports (29) formed in said separator while communicating with lower suction ports formed in a bottom surface of said filter case, said purification chamber communicating with an air feed port (36) connected to an air pump (35). |
