Aq. solutions cooled esp. in crystallisation process - by vacuum direct cooling combined with indirect cooling

摘要

Vacuum-cooling soln. which contain inorganic salts and possibly also acids is as follows. The soln. is cooled under vacuum and the resultant vapour is condensed by direct contact with a continuously recycled cooling liquid; the heat absorbed by this cooling liq. is removed by thermal exchange. The cooling liq. pref. has a b.pt. below that of water and comprises inorganic acids or salts. More specifically, a 30% soln. of H2SO4 is used. Used partic. for cooling solns. in crystallisation processes. Method combines the advantages of direct cooling (vacuum cooling) with those of indirect cooling, minimising their disadvantages.