| 摘要 |
1352190 Separation of polyhydric alcohols from concentrated solutions thereof E P REMY ET CIE 1 July 1971 [7 Aug 1970] 30884/71 Heading B1B A water-miscible substance less volatile than water, e.g. glycerol or a mono- or polyethylene glycol, is vaporized from an aqueous solution thereof by pumping the solution from tank 26 through heater 25, where the solution may be heated to a temperature of 100‹-120‹C., and then introducing it through valve 32 into the upper portion of distillation cloumn 24 the lower portion of which is supplied, through duct 30, with steam at 100‹C. and atmospheric pressure (evaporator 29 being inoperative). A vapour, at a temperature between 110‹ and 150‹C., rich in the required substance leaves the top of the column through duct 42; and may be used to sterilize containers. A dilute aqueous solution of the substance flows from the base of the column into tank 27. When it is desired to concentrate the dilute solution, the various valves are adjusted so that it is pumped from tank 27 through heater 25 and valve 33 into the middle of the column, the base of which is now supplied with hot vapour from evaporator 29. The required concentrated solution flows from the base of the column into tank 26; and watervapour is discharged from the top through duct 41. |
