For caustic soda, caustic soda and concentrated in a falling film evaporator

The present invention discloses a method for caustic soda, caustic soda and concentrated in a falling film evaporator, comprising: an upper end extending into the falling film concentrator tube to the inlet tube alkali lye tank with inlet, to the lower end thereof extends into the evaporation cans inner, outer tube falling film was concentrated with an outer tube, the outer tube is formed between the interlayer and the falling film concentrator tube, the lower end of the outer tube is provided with a molten salt inlet communicating with the sandwich, the upper end of the outer tube are provided with interlayer communication molten salt an outlet, the falling film concentrator tube is provided with a plurality of spiral blade mounting shaft covered with a redistribution of the blade, the blade mounting shaft disposed within the upper falling film concentrator tube, and two-thirds down the length of the film tube lye inlet pipe total length was concentrated cloth uniformly provided with a plurality of grooves on the circumference of the tube film the upper end of the falling film concentrate tank, each membrane cloth are slots through the wall falling film concentrator tube, and are concentrated in the falling film tube to cut is provided. Advantage of the present invention is that: effective membrane cloth, and can effectively prevent damage to the pipe wall falling film was concentrated.