| 摘要 |
PURPOSE:To obtain the titled permselective membrane module having resistance to steam cleaning by forming the membrane of a thermoplastic resin having >=150 deg.C heat-deflection temp., and then immersing the membrane in hot water or an aq. water-soluble compd. soln. at a temp. above 180 deg.C and below the heat-deflection temp. CONSTITUTION:The thermoplastic resin having >=150 deg.C heat-deflection temp. measured at 18.6kg/cm<2> by ASTM-D648 is used as the material of the membrane. Polyether imide, polysulfone, etc., the included in such a resin. An external pressure type tubular permselective membrane is formed with the resin by an appropriate method. The membrane is then heat-treated by immers ing the membrane in hot water or an aq. water-soluble compd. soln. at a temp. above 100 deg.C and below the heat-deflection temp. of the membrane forming resin. The membrane module which is used for treating the hot water of 80-90 deg.C can be preferably treated with steam at 130 deg.C and at 2atm for two hours. The heat treatment is completed while the membrane is immersed, and the membrane is not dried. The amt. of the soln. to be permeated and the fractional characteristic are changed by drying. |
