| 摘要 |
<p>1402187 Percolating filter medium IMPERIAL CHEMICAL INDUSTRIES Ltd 12 April 1973 [24 April 1972 23 Jan 1973] 18823/72 and 3347/73 Heading C1C A packing material for biological treatment of liquid effluent and sewage in a percolating filter, comprises randomly packed extruded hollow open-ended cylindrical pieces of an inert organic polymeric material, the wall of each cylinder comprising, throughout its length, a plurality of corrugations running transversely or obliquely to the main axis of the cylinder and having a depth in excess of the thickness of the wall material. The corrugations, which may be sinewave or castellated in profile, may be either separate or comprised by a single continuous helical thread-like corrugation. The cylinder walls may have multiple perforations, and may terminate in planes lying transverse or oblique to the main axis of the cylinder. The liquid to be treated may be fed continuously or intermittently to the filter.</p> |
