| 摘要 |
<p>A porous fluorocarbon membrane comprising a porous support having the average pore size from 5,0 to 500,0 mcm and the difference by specific weight in one sample of 7,0% max., completely impregnated with copolymer containing 23 - 25 weight percent tetrafluoroethylene and 73 - 75 weight percent vinylidene fluoride and having the ratio of viscosity of the solution thereof in acetone to acetone equal to 2,0 - 4,0. A method for producing a porous fluorocarbon membrane comprising porous support having specified characteristics by dissolving tetrafluoroethylene / vinylidene copolymer in a readily-boiling solvent, mixing said solution with a precipitating mixture of alcohol and water to produce a casting solution, impregnating said porous support with heated casting solution and storing said support for a short time vor evaporating a portion of solvent and partial hardening of a casting solution followed by at least three-zone drying of the resulting membrane with the temperatures increasing from one zone to another in sequence. A cartridge filter comprising protective and supporting cylindrical perforated hollow housings, a pleated porous fluorocarbon membrane having specified design including a prefiltration device and a drainage, placed between said housings and tightly connected to the housing cases of the end caps. A cartridge filter comprises two said membranes superimposed such that membrane closer to the prefiltration device has the pore size ranging from 0,25 to 0,65 mcm, and second membrane has the pore size ranging from 0,15 to 0,45 mcm. <IMAGE></p> |
