Towards a common taxonomy for heat exchanger fouling

Abstract A literature search on the term ‘fouling’ shows that it arises in several, very different, contexts. In process engineering, fouling often refers to the loss in heat exchanger performance resulting from the deposition and/or growth of unwanted layers of material at the heat transfer surface. In 1978 Epstein (Epstein In: Proceedings of the 6th International Heat Transfer Conference (held in 1978). Hemisphere Publishing, New York, 6:701–732, 1981) proposed a characterisation of fouling processes in heat transfer according to the dominant formation mechanism, which was accompanied by a careful classification of terms to describe the different feature. This resulted in Epstein’s seminal paper on the 5 × 5 fouling matrix (Epstein in Heat Transf Eng 4:43–56, 1983). The subsequent 40 years of research in heat exchanger fouling and cleaning have introduced more terms and, on occasion, introduced some confusion in terminology. This is also evident in quantitative treatments of fouling, and recent conferences have featured helpful discussions of terminology for particular cases. There is a case for a systematic review of fouling taxonomy. We present a review of current and previous fouling taxonomies, both written and mathematical, and propose a modification of Epstein ’s matrix. We present a suggested formalisation which could be used as a ‘common language’ to guide understanding for future meetings and publications.