A New Model for the Effect of Calcium Sulfate Scale Formation on Pool Boiling Heat Transfer

Abstract

Scale deposition on the heat transfer surfaces from water containing dissolved salts considerably reduces fuel economy and performance of heat transfer equipment. This problem is more serious during nucleate boiling due to the mechanisms of bubble formation and detachment. Using a precision pool boiling test apparatus, the effects of heat flux and calcium sulfate concentration on heat transfer coefficient and formation and growth of deposits are investigated. The transient change in heat transfer is closely related to wick boiling, and the associated changes in bubble departure diameter and bubble site density. A physically sound prediction model was developed for the prediction of heat transfer coefficients as a function of time during deposition processes. Based on comparison with experimental data over a wide range of foulant concentrations and heat fluxes, the model is considered to be sufficiently accurate for practical application.

Transition of convective heat transfer to subcooled flow boiling due to crystallization fouling

“…~40 o C, (ii) and their small size. The number of steam bubbles as well as their size increase with the surface temperature as shown by Jamialahmadi and Müller-Steinhagen [27]. As the steam bubbles are ejected from the surface, new deposits occur at the base of the bubble due to the micro-layer evaporation at the base of the bubble [15,27].…”

Particulate fouling during the pool boiling heat transfer of MWCNT nanofluid

“…As fouling takes place, the scale layer increases steadily. The capillary diameter of the fouling attenuates and friction resistance augments [12]. Superheat of the scale layer surface reduces and fouling slows down.…”

Effects of Process Parameters on Gypsum Scale Formation in Pipes

“…Scaling in pipes and on vessel walls has continually been a serious problem in various industries [1][2][3][4][5][6][7][8][9][10][11][12]. It reduces the equipment volume capacity, blocks piping, increases corrosion, causes metal fatigue, and decreases heat transfer rates [1][2][3].…”

“…It reduces the equipment volume capacity, blocks piping, increases corrosion, causes metal fatigue, and decreases heat transfer rates [1][2][3]. It can also impair safe equipment operation and lead to contamination of fluids with which the deposits come into contact [4].…”