Circulating evaporator for caustic soda concentration

The utility model discloses a circulating evaporator for caustic soda concentration, which relates to the field of caustic soda production equipment and comprises a base, a casing, an isolation moduleand a plurality of sets of circulating pipelines. Wherein the shell is a container with an open top and is fixed on the base, and a top cover is detachably fixed on the shell. The space in the machine shell is divided into a plurality of evaporation areas by the isolation module, a plurality of obliquely-distributed heating plates are arranged on the isolation module, spray heads are arranged onthe uppermost heating plate, the spray heads spray alkali liquor onto the heating plates, and the alkali liquor can enter the second heating plate after flowing down from the first heating plate and then enters the second heating plate in the same manner. And the alkali liquor can fall into the bottom of the evaporation area until the alkali liquor flows through the surfaces of the plurality of heating plates, so that the