GB1060858A - A process of, and apparatus for, evaporating liquids - Google Patents

Abstract

1,060,858. Evaporators, film-type. W. BUCHI and P. JANOSFIA. Oct. 14, 1963 [Oct. 14, 1962], No. 40391/63. Heading B1B. Liquid is evaporated in the form of a film on the inner surface of vertical cylinders 19, which is surrounded by heating chamber 25, efficient heat-transfer to the liquid film being promoted by setting up interference waves in the film by means of a rotating band spiral 4 which oscillates in a vertical direction. The band is attached at its upper end to bell 3, and may be attached at its lower end to cylinder 5. The diameter of the spiral can be altered by twisting the ends. At its largest diameter the spiral lies on cylinder 19, at its smallest on cylinder 5. The spiral may, alternatively, be used hanging freely downwards over cylinder 5. The bell, cylinder 5 and spiral are rotated at about 500 to 700 r.p.m. by shaft 1. The spiral may be of such elasticity that it oscillates naturally; alternatively the spiral can be a stiff body which is made to oscillate by electro-magnetic or mechanical means. The liquid-to-be-evaporated is introduced into the evoporator through connection 23. The liquid flows through gap 27, between ring 26 and the wall of the housing, onto the inner surface of the heated cylinder 19, where it is distributed as a film. As the liquid evaporates, the most volatile components pass as vapour through holes in bell 3 into space 29, and then leave the evaporator through connection 24. Vapours of the components of intermediate volatility pass through perforations 6 in cylinder 5, and are condensed on cooled tubes 7 and 8. The condensate flows out of the apparatus through connection 14. The unevaporated residue of the feed liquid leaves the evoporator through connection 18. The apparatus may be used for the short-path distillation of liquids of high molecular weight.