Plate heat exchangers fouling mitigation effects in heating of water solutions: A review

Abstract

A comprehensive analysis of publications on fouling in plate heat exchangers (PHEs) on heating water solutions is presented. The peculiarities of flow structure in PHE channels and differences in construction require studies specifically for this efficient type of heat exchanger. The main fouling mechanisms in these conditions are crystallisation and particulate fouling. The predominant way of fouling development in PHE is asymptotic when at some time of fouling growth, the deposition of fouling and its removal to the main flow becomes equal and fouling thermal resistance does not change with time. The data of different experimental research and industry tests show that the rate of fouling in PHE from 5 to 20 times lower than in shell and tube heat exchangers for the same duty and overall process conditions in heating water solutions. The different approaches to modelling fouling formation in PHEs are analysed. The modelling of local process parameters in channels with accounting for the geometry of corrugations on plates is extremely important for the accurate prediction of fouling formation. Among different ways of fouling mitigation in PHE, the accurate design and proper selection of plates and their arrangement is considered the most effective, while covering plates with fouling-reducing coatings has prospects in development and application. The cleaning of PHEs has to be done with the development of optimised maintenance schedules. The cleaning of plate-and-frame PHEs can be done by mechanical methods, but chemical cleaning in place (CIP) with special CIP machines is preferable where it is possible.