Patent ID: 8029675
Filing Date: 2011-10-04
Classification: B01D

Abstract:
1. A multistage membrane distillation process in which vapor from a vapor space ( 11 ) of a vapor generator ( 80 ) having an independent liquid circuit is supplied to a first vapor space ( 81 ) of a first stage ( 86 ), the vapor condensing at condensation walls ( 37 ) bounding the first vapor space ( 81 ), at the side opposite the first vapor space ( 81 ), the condensation walls being respectively adjacent to a flow passage ( 38 ) guiding a liquid ( 20 ) to be concentrated which is bounded at the side opposite to the relevant condensation wall ( 37 ) by a vapor permeable, liquid-tight or water-tight membrane wall ( 36 ) through which the liquid ( 20 ) to be concentrated is separated from a second vapor space ( 83 ) of this first stage ( 86 ), with the vapor arising from the liquid ( 20 ) to be concentrated passing through the membrane wall ( 36 ) into the second vapor space ( 83 ) and a negative pressure is imparted to the liquid ( wherein the vapor from the second vapor space ( the absolute pressure of the liquid ( in the two stages ( in each of the two stages ( a respective condensation and vaporization takes place in at least the two stages ( the corresponding pressure equalization between the respective second vapor space (