Filtering aq. suspensions in filter column - with closed backflushing circuit fed with filtered liq., used for treating contaminated aq. solns., coolants and lubricants from metal machining, etc.

摘要

Treatment of aq. media, contaminated with fine particles and sludges from machining or cleaning processes, involves passing the liq. from a dirty water tank through a labyrinthine filter column (filled with quartz sand, glass beads or the like) to a clean liq. tank. the column is periodically cleaned by back-flushing. Liq. is withdrawn from the clean liq. tank for back-flushing the column in a closed circuit. The contaminated back-flushing liq. is passed from the column to an additional bag filter. The cleaned back-flushing liq. is returned to the clean liq. tank. The contaminants, remaining in the filter bag are disposed of separately. A filter unit for carrying out the process is also claimed. USE/ADVANTAGE - The process is useful for treating contaminated aq. solns., coolant/lubricants, etc. from metal machining and cleaning processes. It provides optimal cleaning of the aq. media, recovers the back-flushing liq. as clean liq. and produces waste only in the form of dry particles which can be easily disposed of or opt. reused.