METHOD FOR SIMULTANEOUSLY COALESCING,FILTERING AND REMOVING OIL TRACES FROM LIQUIDS AND MEDIA FOR ACCOMPLISHING THE SAME

摘要

1,232,231. Removing oil from water; degasser. JOHNSON & JOHNSON. 30 April, 1968 [3 May, 1967], No. 20451/68. Headings BID and B1M. [Also in Divisions D1 and D2] Traces of oil are removed from effluent water by passing it through a multilayer filter element 21 which retains solids and coalesces the oil into large drops which rise into dome 25 downstream of element 21. The element 21 is cylindrical and comprises an expanded metal core, closed at one end, round which is spirally or otherwise wrapped a filter medium comprising polyester, acrylic and/or modacrylic fibres, bonded together by 25 to 100% by weight of polyacrylic or polyurethane resin or a synthetic rubber such as acrylonitrile-butadiene or butadiene-styrene. The layers of medium pass through rollers as they are applied, which are adjusted to produce a progressive variation in density from 0.005 to 0.02 gm./cc. on the inside face to 0.05 to 0.08 gm./cc. outside, and the element has an outer wrapping of wire mesh. Fig. 1 shows two elements 20 operating in parallel and located downstream of a primary filter element 12, which comprises layers of polyacrylic resin-bonded polyester fibres, interspersed by sheets of woven polypropylene monofilament fibres and which is supported by expanded metal, wire mesh or woven fabric. Element 12 removes solids and initiates the coalescing of the oil. Entrained gas bubbles are collected in and removed from dome 18, and any oil which rises into dome 18 flows along passages 16 to dome 25. The water is passed through elements 21 at 0.1 to 0.35 feet per minute, to optimise coalescence. The fibre denier and filter element pore size are exemplified.