Question

Difference between scales and sludge

Answer 1

Answer:

if the precipitated matter forms a hard, adhering crust/coating on the inner walls of the boiler, it is called scale.

Sludge is a soft, loose and slimy precipitate formed within the comparatively colder portions of the boiler and collects in areas of the system, where the flow rate is slow or at bends. Sludge’s are formed by substances which have greater solubility in hot water than in cold water, e.g., MgCO3, MgCl2, CaCl2, MgSO4, etc.