Initiation of Boiler Scale Formation

Abstract

This paper describes part of a programme of fundamental study of scale formation. The work described here is concerned with the initiation of scale formation at a heating surface where boiling is taking place. The crystalline ring formations first observed by Partridge (I) with calcium sulphate solution were seen using a range of other solutions under various flow conditions. A variety of other formations based on Partridge's rings were also observed. The theory advanced by Partridge that these deposits are due to evaporation at the triple interface of steam bubble, heating surface and solution was in general confirmed. A dynamic mechanism is proposed to explain these formations.