Method of washing an upflow filter and filter bed employed in said filter

摘要: A method of washing an upflow filter (12) between service runs employs a bed (26) having non-buoyant particulate layer (56) through which influent to be filtered is directed in upward direction, and liquid employed the operation direction. two-stage includes steps first directing combination air direction with velocity being less than minimum fluid-ization (56), for disrupting only some floc retained during previous run, thereafter up-flow at fluidization removing disrupted from while leav-ing attached said media layer. The process most preferably carried out including coarse, flocculation (52) distributing flow promoting flocculation.