TP24-14 The Effect of Scale and Fouling on Heat Transfer Efficiency

Heat exchangers in service are subject to various types of fouling, among them mineral scale and biofilm formation. This paper discusses the effects of scale and biofilms on heat exchanger performance. Various degrees of deposition are modeled and the resulting impact on key performance parameters are discussed. These include overall heat transfer coefficient, temperature, flow, and pressure drop. The impact on fouling coefficients on both the process and water sides are also discussed. Errors resulting from traditional modeling practices are described and practical examples are provided to illustrate the maintenance economics, i.e., when is it time to clean the heat exchanger?