The present invention provides a method for purifying liquid by membrane distillation,
The heated vaporized stream was a liquid (retentate stream) through a retentate channel along a porous hydrophobic membrane (10), whereby vapor of the liquid of the membrane through the pores of the membrane flowing on the other side, and to condense the steam at the other side of the membrane, giving a distillate stream in a distillate channel (5), wherein the condensate toward the condenser surface (3) is produced by passing the heat of condensation of the (latent), said condenser surface, a non-porous separation is formed between the feed stream of the liquid to be purified and said distillate stream, said feed stream, the in concentrate stream countercurrently passed through a feed channel (2), its feed within the channel spacers object (4) is arranged, whereby at least a portion of the latent heat, the via the condenser surface transferred to the feed stream, and the positive liquid pressure difference between the retentate stream and (9) and the feed stream, across each of the at least a portion of the concentrate channel and the feed channel whereby said concentrated including that applied at the corresponding point of the object channel and the feed channel, to provide the way. The present invention further provides a suitable device for use in the method.

.FIELD 2