| 摘要 |
<p>An upward flow filter bed 18 of foamed plastic particles is retained by screens 46,48 in a vessel 11 between influent inlet 20 or 28 and filtrate outlet 30. The bed is periodically cleaned by reverse flow liquid delivered through line 50 and distributor 34 and by upward flow of air from manifold 65, the air being directed into the bed at 135 degrees to the downward flow of backward liquid, in order to tumble the bed particles and enhance cleaning. The backwash liquid and air may be delivered simultaneously or alternately. <IMAGE></p> |
