32%→50%NaOH technical flow process

We adopt the "three-effect countercurrent falling film evaporation" process. The 32% NaOH solution sent from outside the boundary area is added to the III-effect falling film evaporator, where its concentration is increased from 32% to 36%. After being concentrated, the caustic soda solution is pressurized by the III-effect pump and then heated by the preheaters of the II-effect first and second stages before entering the II-effect falling film evaporator, where its concentration is further increased to 42%. The concentrated caustic soda solution is then pressurized by the II-effect caustic soda solution pump, heated by the preheaters of the I-effect first and second stages, and enters the I-effect falling film evaporator, where its concentration is raised to 50%. The caustic soda solution that has reached the desired concentration is pressurized by the I-effect caustic soda solution pump, cooled by the preheaters of the I-effect second stage and II-effect second stage as well as the caustic soda solution cooler, and then sent to the finished caustic soda tank outside the boundary area for storage.