A5.4 - Clean or not clean - Detecting fouling in heat exchangers

Abstract

Fouling describes unwanted deposits on heat transferring surfaces leading to reduced heat transfer and increased heat transfer resistance. Hence, fouling is a severe issue particularly in food processing because product quality and safety cannot be ensured, and plant efficiency is reduced. As a result, cleaning is performed which limits processing time and increases plant downtime as well as costs because usually it cannot be adapted to amount and type of fouling present. Monitoring of cleaning and fouling requires high demands for measuring and analysing systems in heat exchangers being closed systems. A short overview is given over different monitoring methods in heat exchangers which can be applied both for fouling detection and cleaning supervision and, in a next step, adaption. Several experimental (pressure drop, temperature, heat transfer parameters, electrical parameters, acoustics) and computational methods are presented and compared. Primary focus of presented methods is acoustic methods.