Patent ID: 8486223
Filing Date: 2013-07-16
Classification: B01D

Abstract:
1. A falling film evaporator comprising a shell having a top and a bottom, multiple tubes parallel to each other installed vertically inside the shell, each tube having a top, a bottom, smooth surface on its inner wall, and a protrusion above a horizontal surface on the top of the multiple tubes, a steam inlet on the top of the shell, a condensed steam outlet at the bottom of the shell, an inlet for an aqueous solution on the top of the tube, an outlet for the aqueous solution at the bottom of the tube, a distributing assembly below the inlet for the aqueous solution having two or more distributing trays that are installed horizontally and arranged vertically from top to bottom, each tray being in a form of a disc that increases in diameter from the top to the bottom, and each disc having multiple holes that are substantially uniformly distributed thereon, and a plate that forms the horizontal surface on the top of the multiple tubes and below the distributing assembly for collecting the aqueous solution, wherein the protrusion on the top portion of the tube above the horizontal surface of the plate causes an overflow of the aqueous solution into the tube to form a film along the inner wall of the tube.