On line tube cleaning systems for polyphosphate plants

✍ Scribed by S.V. Cabibbo; J.T. Callahan

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 400 KB
• Volume: 23
• Category: Article
• ISSN: 0011-9164
• DOI: 10.1016/s0011-9164(00)82533-3

✦ Synopsis

The feedwater to MSF (multi-stage flash) seawater evaporator plants must be pre-treated to prevent the formation of the so-called "alkaline scales", namely calcium carbonate, CaCo S and magnesium hydroxide, Mg(OH)2. Untreated seawater contains calcium bicarbonate, Ca(HC0)2, which when heated above 50°C (122OF) decomposes to form CaCOS scale and carbon dioxide. The accompanying rise in pH can also cause the precipitation of Mg(OH)2. The deposition of these alkaline scales on the tubes of the evaporators and particularly in the brine heater, severly impairs the heat transfer in the evaporator.