摘要 |
<p>877 ROTARY DRUM FILTER AND METHOD OF OPERATION FOR MEDIUM CLEANING A rotary vacuum filter wherein each filtration sector of the filter is backwashed with filtrate and/or separately supplied gas or wash liquid while the sector is submerged in the feed slurry in the tank. As each sector starts to resubmerge in the tank, vacuum is applied so that the sector and associated hydraulic system is quickly and completely filled ith filtrate and a thin cake or film of solids forms on the filter medium whereupon with the sector still submerged, vacuum is cut off and a positive pressure is applied by either or both pressured gas or liquid supplied through the valve thus forcing filtrate back through the cloth to effect washing thereof. After the wash, vacuum is reapplied for cake formation. The drum includes an internal manifold under each filtration sector. The manifolds are mounted on the interior wall of the drum and are secured directly to the drum wall as structural members. Additionally, each manifold serves as a reservoir for storage of wash liquor.</p> |