公开(公告)号：DE1618136A1

公开(公告)日：1971-03-11

申请号：DEB0092089

申请日：1967-04-15

Applicant: BASF AG

Inventor： WIRTH FRIEDRICH DR ,  SUTER HUBERT DR ,  MANN WALTER DIPL-ING ,  SCHAEFER GERHARD DIPL-ING

IPC: C07C51/573 ,  B01D3/00

Abstract: 1,180,117. Distillation columns; purification of phthalic anhydride. BADISCHE ANILIN-& SODA-FABRIK A.G. 19 May, 1967 [21 May, 1966; 15 April, 1967], No. 23398/67. Heading BIB. [Also in Division. C2] Phthalic anhydride is purified by distillation in a plant comprising two fractionating columns 1, 5 of the tray-type connected as shown to two evaporators 2, 8 each containing a vertically-disposed bundle of tubes, the arrangement being such that the distilland flows down as a thin film on the inside of the tubes. The material to be purified is introduced about half-way up column 1, which is maintained under reduced pressure. Vapours comprising about 37% of the feed, including all the low-boiling impurities, leave the head of column 1, and are condensed; and part of the condensate is refluxed to the column. Highboiling impurities are withdrawn from the system through line 9. Purified phthalic anhydride is obtained at the head of column 5.

公开(公告)号：DE1619841A1

公开(公告)日：1971-03-25

申请号：DE1619841

申请日：1967-11-03

Applicant: BASF AG

Inventor： MANN WALTER DIPL-ING ,  WAGNER JOACHIM DIPL-ING ,  JAEGER WERNER

IPC: B01D7/02

Abstract: 1,235,360. Separation of sublimed material from gases. BADISCHE ANILIN-& SODAFABRIK A.G. 1 Nov., 1968 [3 Nov., 1967], No. 51927/68. Heading BIB. [Also in Division F4] Sublimed material, e.g. phthalic anhydride, admixed in vapour form with a gas is separated from the gas by passing the mixture through inlet 1 into a casing which contains, a system of tubes through which cooling medium is circulated so that the sublimed material solidifies on the tube system and the depleted gas leaves the casing through outlet 2. Heating medium is then circulated through the tube system so that the solid sublimed material melts and the liquid flows out of the casing. During the whole operation the casing is maintained at a substantially constant temperature, which is above the melting temperature of the sublimed material, by means of heating tubes 10 on the outside of the casing the tube system 10 is denser at the lower part of the casing. The internal tube system, which rests on rods 3 held in two supporting walls 4, comprises parallel coils a, b, c, each consisting of a tube winding backwards and forwards by means of 180‹ bends. The supporting walls 4 are held loosely in rails 6. Oil may be used as heat-exchange medium for the coils. Steam may be used to heat tubes 10. The apparatus may be constructed by laying one of the walls 4 in a horizontal position, securing the rods 3 thereto, placing the coils a. b. c, in position, securing the free ends of the rods to the other wall 4, turning the construction through 90‹, and introducing it into the casing.