Ultrafiltration for oily degreasing baths in electroplating surface treatment regeneration par ultrafiltration des bains de degraissage chimique dans une chaine de traitements de surface

The process of ultrafiltration plant used for remove dissolved and emulsifield oil of degreasing baths in Legrand electroplating surface treatments is discribed. In this way the bath life utilization is prolonged from 80 to 400 hours.Sequential batch operation is automaticaly programmed. Ultrafiltration membrane are of tubular configuration with polysulfone polymer which is resistant in the 2-13 pH range and thermally stable up to 60°C. The molecular cutoff is around 20,000: the concentrate stream is enriched up to 30% by weight by mineral oil and suspended solids are also removed. The permeate contained less than 80 mg.l-1 amount of oil. Operating cost 500 000 F (1986) will be compensed on 2 years.