A Statistical Model for Fouling of a Plate Heat Exchanger by Whey Protein Solution at UHT Conditions

Abstract

Fouling of heat transfer equipment is a severe practical problem which is still poorly understood on an industrial level. Although the chemistry of fouling from milk fluids is qualitatively understood, and mathematical models for fouling at low temperatures exist, the behaviour of systems at UHT temperatures is still unclear. Experiments have been carried out to monitor fouling from whey protein solutions in a commercial plate heat exchanger supplied by APV Baker, which incorporates a tubular test section to allow comparison between fouling in plate and tubular geometries. Heat transfer coefficients and pressure drops were measured during fouling in all sections of the exchanger. A statistically-designed series of experiments has been conducted to study and quantify the significance of a number of factors, including β -lactoglobulin reaction rate, on fouling within a UHT process. Reaction rate can be used to correlate fouling data in the UHT part of the exchanger: data fits have also been produced to correlate both pressure drop and heat transfer data. The experiments suggest that simple reaction models may be useful for predicting the behaviour of industrial plant.