ABSORBER-CRYSTALLIZER

摘要

1390213 Combined crystallizer and classifier OLIN CORP 21 Nov 1972 [29 Dec 1971] 53773/72 Heading B1G An absorber-crystallizer for example as shown, comprises (a) a vertical cylinder 12, surmounted by a conical top 11, with at its base a frustoconical bottom 29, and a gas inlet 28, e.g. for CO 2 , in the wall of the cylinder and a gas outlet 13, in the conical top (b) external of the cylinder a group of tapered circumferential manifolds 14, 15, 16, at a level intermediate sand top and bottom with means to supply liquid to the group of manifolds (c) a group of spray headers 19 inside cylinder 12 which deliver liquid upwardly and inwardly therein and liquid-conducting means 18, between each member of the spray headers and a member of the group of manifolds, (d) a spray header in the conical section of the top arranged to direct liquid upwardly against the inner surface of the top (e) a false bottom 30, open at its ends and sealed at its upper end to the walls of the cylinder, which extends downwardly and is spaced inwardly from the frusto conical bottom and which functions to separate the crystallization zone 2 above from a classification zone 3, formed between the false bottom and the walls of the frustoconical bottom, and means e.g. a foraminous screen 32, to permit passage of liquid from the crystallization zone into the classification zone while restricting passage of oversized crystalline material and (f) means for removing liquid from the classification zone e.g. outlet 36 for removing fine entrained crystals and outlet 37 for removing mother liquor. Trough 26 immediately below the header ports serves to collect spillage while the header port is open. Access ports 27 are provided in the conical roof. The crystallization and classification zones are connected by trapezoidal linkages 24. These linkages also assist in support and guidances during assembly and disassembly of connections 18 and alignment of the spray headers 19. An example is given of the production of sodium bicarbonate by carbonization of soda ash solutions. The apparatus may also be used for producing sodium bicarbonate from CO 2 and NaOH, potassium bicarbonate from KOH and CO 2 , sodium bisulphite from sodium sulphite and SO 2 , sodium bifluoride from NaF and HF, and diammonium phosphate from phosphoric acid or monoammonium phosphate and ammonia.