ARTICLE:

• HEAT AND MASS TRANSFER IN FOULING  download article

S. H. Chan
Department of Mechanical Engineering, The University of Wisconsin-Milwaukee, P.O.Box 784 Milwaukee, Wisconsin 53201, USA

ABSTRACT

Recent advances in analytical modeling of silica and calcium carbonate depositions on heat exchanger surfaces are reviewed. General physical and chemical processes leading to CaCO₃ fouling are described. The CaCO₃ fouling model assumes that the deposition process is controlled by two processes: the mass transport of ions and molecular species to and from heat transfer surface, and the crystallization reaction on the same surface. Analytical predictions of the CaCO₃ deposition flux, the mean, and the profile of the local fouling-layer thickness along a heated plate by a laminar falling film are presented. They are found to be in good agreement with experimental data. Good agreement is also shown when applied to a turbulent annulus flow system. Similarly, physical and chemical processes pertinent to silica fouling are reviewed. Silica deposition models that account for supersaturation, pH factor, salinity, and thermal-hydraulic effects are presented. Analytical predictions are made and results are then compared to the field and laboratory data.

 download article

363-402 pages

« Previous article         Next article »