GB1266194A - - Google Patents

Abstract

1,266,194. Evaporators, film-type; desalination of water. UNIVERSITY OF NEWCASTLE, AUSTRALIA. 9 April, 1969 [11 April, 1968], No. 18169/69. Heading B1B. Salt water is distributed from pool 11 by resilient blade 23 so that a thin film of salt water is formed on the outside surface of a hollow, heat-conductive cylinder 12, which is rotated about it's horizontal axis, and hot vapour is introduced into the interior of the cylinder through apertures in pipe 33. Some of the water is evaporated from the film; the vapour passes through outlets 31 in the casing 10, is drawn into a compressor (not shown), and the compressed vapour is introduced through pipe 33 into cylinder 12 wherein it condenses. The condensate, i.e. desalinated water, leaves the cylinder through ports 13. Residual brine is removed from the outer surface of cylinder 12 by resilient blade 24 in discharge zone 20 which is supplied with washing water through conduit 22a. The interior wall of cylinder 12 is formed with longitudinal projections or flutes 38 (Fig. 3) so that vapour condenses on the flutes, the condensate being forced by centrifugal action into channels, from which it flows to ports 13. Blades 23 and 24 may be replaced by pads of porous material, e.g. of nylon. Two or more units of the above type may be asembled for multipleeffect operation, the cylinder of the first effect being heated by steam from a conventional steam generator, the vapour produced in the first effect being used to heat the cylinder of the second effect, and so on. In another embodiment there may be a number of concentric annular vaporization and condensation zones, each defined by concentric rotatable film carriers located within a single housing. An apparatus is referred to wherein salt water is fed into a pool on the inside of the rotating cylinder, and the vapour is condensed on the outside.