| 摘要 |
<p>1469940 Ultrafiltration THETFORD CORP 13 Dec 1974 [23 Jan 1974] 54016/74 Heading B1X [Also in Divisions C1 and E1] In a sewage treatment plant, (Divs. Cl and E1), sewage is biologically treated in a tank 72 and then pumped through an ultrafiltration device 98. The water permeate is further filtered by activated charcoal in tank 110 and led to a storage tank 108. The concentrated sewage is returned by pipe 100 through a throttle 102 to the tank 72. The device 98 comprises two co-axial tubes 126, 130, the inner 126 being a semi-permeable membrane mounted on a porous tube 128. A rod 198 mounted co-axially in tube 126 ensures the sewage is in close contact with the tube 126. A by-pass 132 to the throttle 102 may be periodically opened. This increases the rate of flow and thereby flushes the membrane 126.</p> |
