Chemical Removal of Calcium Sulfate Scale.

Abstract

Laboratory tests hawe shown that 30 Lo 50% sodium hydroxide solutions react with calcium sulfate scale more completely than do lower concentrations of sodium hydroxide. The oplimum temperatures are above 1 7 P F. Commercial heat exchange units have been treated with 30 to 50y0 sodium hydroxide solutions to remove the calcium sulfate scale. Ai dctailed description is included here for the treatment of a 50,000-