Film distribution device in falling-film evaporator for concentration of caustic soda and caustic soda flakes

The invention discloses a film distribution device in a falling-film evaporator for the concentration of caustic soda and caustic soda flakes. The film distribution device comprises a falling-film concentration pipe, wherein the upper end of the falling-film concentration pipe extends into a soda liquor inlet pipe box, a soda liquor inlet is formed on the soda liquor inlet pipe box, and a plurality of film distribution grooves are uniformly formed in the circumference of the upper end part of the falling-film concentration pipe in the soda liquor inlet pipe box, penetrate through the wall of the falling-film concentration pipe and are arranged along a same rotation direction tangent to the falling-film concentration pipe. The film distribution device disclosed by the invention has the advantages that the structure is simple and practical; as the film distribution grooves are formed along the tangent direction of the falling-film concentration pipe, even if the flow velocity of soda liquor is high, a film also