SCALE REDUCTION IN DESALINATION BY CALCIUM SULFATE SOLUBILITY INVERSION

The purpose of the research was to find a method for reducing or eliminating calcium sulfate scale in saline water conversion processes employing distillation or evaporation. The principle of the proposed method depends on the use of additives to sea water which would give calcium sulfate a normal rather than inverted solubility behavior so it would not tend to deposit on heat transfer surfaces. After determining extensive data on almost fifty compounds, only three were found which, in relatively low concentrations, had the characteristics of holding the transient solubility of calcium sulfate in sea water practically invariant with temperatures up to 255 F. These compounds were ( 1 ) sodium acrylate ( 2 ) an anionic polyacrylamide and ( 3 ) an acrylic acid-amide copolymer. Tests run in an experimental evaporator using 10-20 p.p.m. of these promising additives showed remarkable reduction in scale formation on heat transfer surfaces. Preliminary economic evaluation indicated that the cost of additives may be reduced to one or two cents per 1000 gallons of fresh water produced. ( Author )

• Corporate Authors:

  University of Rhode Island, Narragansett

  Narragansett, RI  United States  02882
• Authors:
  • THOMPSON, A R
• Publication Date: 1967-9

Media Info

• Pagination: 16 p.

Subject/Index Terms

• TRT Terms: Desalination; Distillation
• Subject Areas: Environment; Marine Transportation;

Filing Info

• Accession Number: 00005977
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: W69-07469 Tech Rpt., OWRR-A-0120RI( 2 )
• Contract Numbers: DI-14-01-0001-810, DI-14-01-0001-985
• Files: TRIS
• Created Date: Nov 25 1974 12:00AM