Abstract: The present invention relates to a plate heat exchanger for treatment of a feed. The plate heat exchanger includes a plate package comprising a plurality of heat exchanging plates and defining a heating volume, a cooling volume and a plurality of process volumes. Each of the process volumes includes an evaporation section for evaporation of a part of the feed, a separation section for separating a non-evaporated part from an evaporated part of the feed, and a condensation section being arranged to condense the evaporated part of the feed. Each heat exchanging plate defines a first thermal interface between the heating volume and the evaporation section of a first process volume, a second thermal interface between the cooling volume and the condensation section of a second process volume, and at least one further thermal interface between an evaporation section and a condensation section of two adjacent process volumes.