MEMBRANE DISTILLATION METHOD FOR THE PURIFICATION OF A LIQUID

摘要

THE INVENTION PROVIDES A METHOD FOR THE PURIFICATION OF A LIQUID BY MEMBRANE DISTILLATION COMPRISING: -PASSING A HEATED VAPOURISING STREAM OF A LIQUID (RETENTATE STREAM) THROUGH A RETENTATE CHANNEL ALONG A POROUS HYDROPHOBIC MEMBRANE, WHEREBY VAPOUR OF THE LIQUID FLOWS VIA THE PORES OF THE MEMBRANE TO THE OTHER SIDE OF SAID MEMBRANE, AND -CONDENSING SAID VAPOUR ON THE OTHER SIDE OF SAID MEMBRANE TO GIVE A DISTILLATE STREAM IN A DISTILLATE CHANNEL WHICH DISTILLATE IS CREATED BY PASSING THE HEAT OF CONDENSATION (LATENT HEAT) TOWARDS A CONDENSER SURFACE, SAID CONDENSER SURFACE FORMING A NON-POROUS SEPARATION BETWEEN A FEED STREAM OF THE LIQUID TO BE PURIFIED AND SAID DISTILLATE STREAM, WHICH FEED STREAM IS PASSED THROUGH A FEED CHANNEL IN COUNTER-CURRENT WITH THE RETENTATE STREAM, IN WHICH FEED CHANNEL A SPACE MATERIAL IS ARRANGED WHEREBY AT LEAST PART OF THE LATENT HEAT IS TRANSFERRED VIA THE CONDENSER SURFACE TO THE FEED STREAM, AND WHEREBY A POSITIVE LIQUID PRESSURE DIFFERENCE IS APPLIED BETWEEN THE RETENTATE STREAM AND THE FEED STREAM AT THE CORRESPONDING POINTS OF THE RETENTATE CHANNEL AND THE FEED CHANNEL OVER AT LEAST A PART OF EACH OF THE RETENTATE CHANNEL AND FEED CHANNEL. THE INVENTION FURTHER PROVIDES AN APPARATUS SUITABLE FOR USE IN SAID METHOD.