Prevention of calcium sulphate scale formation in evaporation plants by ion exchange

✍ Scribed by Gianfranco Boari; Lorenzo Liberti; Roberto Passino

• Publisher: Elsevier Science
• Year: 1974
• Tongue: English
• Weight: 781 KB
• Volume: 102
• Category: Article
• ISSN: 1873-3778
• DOI: 10.1016/s0021-9673(01)85470-4

✦ Synopsis

A process has been developed that enables sulphate in sea-water feed to distillation plants to be replaced by chloride ions by means of weak anion-exchange resins. Calcium sulphate scales are thus prevented from forming on heat-exchange surfaces. Only the blow-down discharged from the evaporation plant is used to regenerate the resin. After a preliminary evaluation on a laboratory basis, pilot-plant tests, run for about 7500 h on a combined multiflash-desulphation unit, fully confirmed the feasibility of the process. Based on these results, a 2000 m3/d advanced multiflash plant will be erected near Bari with a maximum operating temperature of 150" and a recovery ratio of 20 kg of water per kg of vapour.