POROUS FLUOROCARBON MEMBRANE, METHOD OF ITS PREPARATION, AND CARTRIDGE FILTER BASED ON THIS MEMBRANE Russian patent published in 1998 - IPC

FIELD: filtration technics. SUBSTANCE: invention deals with porous fluorocarbon membrane comprising porous basis with average pore size from 5.0 to 500.0 mcm and density difference within one sample no more than 7.0%, which is completely impregnated with tetrafluoroethylene (23-25 wt %)- vinylidenefluoride copolymer at ratio of its acetone solution density to density of acetone itself from 2.0 to 4.0. The membrane is obtained by dissolving above-indicated copolymer in volatile solvent, mixing solution with alcohol-water precipitation mixture to give working solution. This solution, when heated, is employed to impregnate porous basis, after which the latter is allowed to stand for a short time to vaporize part of solvent and to harden working solution. Resultant membrane is dried and used in cartridge filter. Filter is executed from protective and supporting cylindrical perforated hollow casings, two stacked up crimped porous fluorocarbon membranes, prefilter, and drainage disposed between indicated casings and tightly joined with bodies of end covers. Membrane neighboring to prefilter has pore size 0.25-0.65 mcm, and the other 0.15-0.45 mcm. EFFECT: enhanced efficiency of filtration of chemically active media. 14 cl, 4 dwg, 3 tbl, 20 ex