Abstract: An evaporator system including a plurality of effects arranged in series for progressively concentrating a liquid, the effects each including: a header chamber for receiving liquid to be concentrated; a multiplicity of tubes adapted to provide evaporation of liquid from the inner surfaces of the tubes and a perforated distributor plate located in the header chamber to distribute liquid to the openings of the tubes; and wherein the evaporator system is provided with a branched wash liquid feed line for providing parallel feeding of wash liquid to the header chambers of the effects onto the distributor plates therein. Each distributor plate comprises an essentially planar plate member having a multiplicity of distributor holes therein for distributing liquid to be evaporated to the multiplicity of tubes therebelow and a series of overflow conduits for providing a flow of wash liquid through the plate to the tubes.