Additives for alkaline scale control at temperatures above 93°C (200°F)

Abstract

Laboratory tests have been used to screen chemical additives suitable for alkaline scale control at temperatures between 93°C and 121°C (200–250°C). The tests have shown that the quantity of solids deposited and the heat transfer performance depend to some extent upon the physical nature of the deposit and that this depends in turn upon the type of chemical used. Low molecular weight polyelectrolytes have been found the most suitable additives and a polymeric carboxylic acid has been found particularly effective. The chemical is being field tested and initial results indicate a 36-day operating period between acid cleans.