GB1163364A - Falling Film Evaporator - Google Patents

Abstract

1,163,364. Evaporators, falling film type. A. E. ROSENBLAD. 3 Nov., 1967, No. 50124/67. Heading B1B. Liquid is evaporated from films of the liquid flowing down the outer surfaces of vertical, parallel plates 12 which form opposite walls of a plurality of hollow heating elements 11 spaced form a casing 14 so that the vapours formed in the channels between adjacent heating elements flow out of the channels at both vertical edges of the elements and enter the spaces 18 between the elements and the casing. The vapours are withdrawn from the casing through two conduits 32 which are at a position below the upper edges of the heating elements. The evaporator shown is of the vapour-compression type in which the vapour is drawn through conduits 32 by compressor 34, and the compressed vapour is introduced through manifolds 22 and pipes 25 into the interior of the hollow heating elements, wherein the vapour condenses. The condensate flows out of the hollow elements through pipes 29 into tank 39 from which gases are discharged via pipe 44. The liquid to be evaporated is supplied to the upper edges 59 of heating elements through pipe 52 and spray nozzles 57. Concentrated liquid, remaining after the evaporation, is withdrawn from the bottom of casing 14 by pump 51. Some of the concentrate may be recirculated to the evaporator through pipe 52, the remainder being withdrawn from the system through pipe 46. The compressor 34 may be omitted, and the evaporator joined by pipe 32 to a series of similar units connected for multipleeffect operation.