Calcium sulphate is a common component of fouling deposits in industrial heat exchangers, because its solubility
decreases with increasing temperature.
The internal surfaces of water heat exchangers are in contact with water to produce heat transfer. Water used for
heat transfer inevitably contains dissolved solids due to inefficient water purification processes.
Some salts (e.g. calcium sulphate and calcium carbonate salts) decrease solubility at higher temperature and hence
deposit (scale) on the exchanger surface. The scale & deposits in heat transfer tubes are generally non-metallic and
therefore possess low thermal conductivity, which impedes transfer of heat and thereby affects the efficiency of
the heat transfer equipment. Periodic cleaning of the exchangers is mandatory for an optimal thermal efficiency. Various
methods for descaling are available and are used standalone or in combinations. Chemical cleaning is frequently
employed for cleaning complex exchanger surfaces. Since the scale compositions vary depending on many factors, a solution
has to be customized for specific applications.
Calcium Sulphate Descaler
Calcium sulphate scale is insoluble in water. Calcium sulphate scale is soluble in diluted solutions of ScaleAwayA773TM.
Calcium scale can be removed using a 5-15% solution of ScaleAway773TM. Scale is removed at a much
slower rate than ScaleAwaySFATM for calcium carbonate scale, thus descaling of calcium sulphate scale needs to be kept
under control with constant management using standard CIP systems and chemical dosing systems.
Stable and Odourless
Under working conditions, ScaleAwayA773TM solutions remain stable, however at elevated temperatures, ScaleAwayA773TM
can decompose. Under working conditions and temperatures up to the boiling point, ScaleAwayA773TM solutions remain
Solutions of ScaleAwayA773TM are less corrosive and require lower and retain excellent scale removing efficiency. Solutions of
ScaleAwayA773TM may be used on stainless steel (304 or 316 up to boiling temperatures) without corrosion inhibitors,
while typical industrial inhibitors like ScaleAwayPPETM at low concentrations, can be used in mild steel applications.
Comparable inhibitors for ScaleAwaySFATM require higher concentrations for adequate protection.
ScaleAway773TM does not chelate, therefore, metal redepositing is not an issue with ScaleAway773TM.
Product information on ScaleAwayA773TM