Understanding and preventing heat exchanger fouling

When operating in exceptionally challenging conditions, or handling difficult materials such as sewage and wastewater sludges, even the best designed heat exchangers will be susceptible to fouling. Understanding the different types of fouling and what causes them will help engineers and operators pick the best type of heat exchanger for their particular application and keep it running in optimum condition.

The impact of fouling in heat exchangers has been recognised since 1910 when the first research on the issue was carried out. Since then there have been many developments, from patented solutions to standard good practice such as maintaining flow rates and carefully controlling temperatures. A well designed heat exchanger will take the standard ‘fouling factor’ for the material it is to handle into account at the specification stage, ensuring that sufficient heat exchange occurs when normal levels of fouling are experienced in operation.