SEPARATION MEMBRANE AND USAGE THEREOF

摘要

PURPOSE:To obtain a separation membrane which can be utilized in a membrane distillation type separation method of a liquid-liquid system and a gas-liquid system and is improved in water-permeability by constituting the separation membrane of a hydrophobic porous membrane wherein hydrophilic substance is stuck on the surface of the fine holes. CONSTITUTION:A separation membrane is constituted by sticking hydrophilic substance (e.g. glycerin) on the surfaces of the fine holes of a hydrophobic porous membrane made of polytetrafluoroethylene, etc. The mean pore diameter of the fine holes is preferably regulated to a range within about 20Angstrom and about 0.1mum. Further the rate of amount of stuck hydrophilic substance for the weight of membrane material is preferably regulated to a range within about 0.01-5wt.%. This separation membrane is utilized in the membrane separation method of a liquid-liquid system wherein water contained in liquid is separated while holding the temp. as driving force of separation. Furthermore this separation membrane is utilized in the membrane separation of a gas-liquid system wherein liquid is supplied to the primary side of this membrane and the secondary side is held in a vapor phase and steam passed through this membrane is cooled and collected. As a result, the separation membrane is obtained which is excellent in water-permeability.