| 摘要 |
A unit is disclosed for removal of impurities present in liquids such as waste water effluent. The unit comprises a vessel containing a loose quantity of particulate treating material for absorption or reaction with the impurities in the liquid. A wall of the unit has multiple small openings therein, each of the openings filled with a finely-divided, compacted, particulate filter material such as diatomaceous earth which is retained in the openings by one or more layers of a woven inert material such as nylon or polyester having mesh openings sufficiently small to prevent passage of the particulate filter material therethrough. The woven material is secured over the outer surface of the openings in the wall of the vessel. Means are mounted within the vessel to progressively sweep over the inner surface of the wall just out of contact therewith and over the openings in which the particulate filter material is retained to remove impurities lodged thereon and prevent blinding of the filter material by such impurities. The same means also acts to uniformly mix the particulate treating material held within the vessel. The liquid with the impurities removed, because of the pressure differential between the inside and outside of the vessel, passes through the particulate filter material retained in the small openings of the vessel and is discharged from the housing surrounding the vessel. The treating material, once spent, is replaced as necessary. |
