Improvements in and relating to the dehydration of organic liquids

摘要

In a continuous process for obtaining dehydrated organic liquids e.g. alcohol, propyl alcohol, glycol chlorhydrin, by a combination of ordinary distillation and azeotropic methods, the organic liquid is withdrawn, at a concentration greater than that of an azeotropic mixture of the liquid and water, from a point situated between that part of the apparatus where concentration takes place and that part where the azeotropic mixture is treated. A steam-heated distillation column 1 having the usual extraction zone I and concentration zone II is provided at the top with additional plates forming an azeotropic distillation zone III in which an entrainer liquid acts indefinitely. Wort to be concentrated is supplied through a pipe 16 and heat-changer 17 where it is preheated by the exhausted vinasses drawn off through a pipe 18. The alcoholic vapours rising in the column cause the entrainer liquid e.g. a mixture of petrol and benzene placed in the zone III to boil and the vapours evolved are condensed in a condenser 4 and the condensate separated into two layers the upper layer being returned to the zone III by a pipe 7 and the lower layer through a pipe 8 to the zone II. Concentrated alcohol mixed with entrainer liquid is drawn off by a pipe 9 from a plate between the zones II and III and is delivered to a small column 10 partly heated by steam and partly by alcoholic vapours circulated from the zone II through an exchanger II by pipes 13, 13a, the anhydrous alcohol being drawn off through a pipe 14. An auxiliary condenser 3 is provided to relieve the condenser 4 the condensate being separated into layers which are returned through pipes 5, 6. Entrainer liquid vapourized in the column 10 is condensed and returned through a pipe 15. Specifications 243,368, 253,128, and 289,051, [all in Class 32, Distilling &c.], are referred to.