The heat transfer area of heat exchangers can corrode (oxidization, rust, etc.) and accumulate deposits (sludge, minerals, lime, etc) during operation.
Especially in industry, enormous amounts of waste heat in the form of polluted exhaust air are emitted unused into the environment. In such cases, heat recovery via a heat exchanger is often not possible due to pollution.
These undesirable effects are referred to as “fouling” and deteriorate the overall heat transfer. There are different possibilities to deal with fouling, such as:
- “Cleaning” the fluid stream that causes fouling through inertia separation, wet separation, adsorption, thermal or catalytic oxidation, etc.
- Allow fouling in the heat exchanger to occur: enlargement of the heat exchanger’s surface, mechanical cleaning, chemical cleaning, partial redundancy, redundancy
- Minimizing fouling in the heat exchanger: material selection, surface coating, flow optimization, adjustment of the flow velocity, addition of chemicals, mechanical removement of fouling layer
There are different types of heat exchangers (e.g. plate, shell and tube or field-tube heat exchangers). Selecting the heat exchanger is determined by the given heat transfer task and presupposes precise knowledge about its power-reducing factors. Through the development of computational models and with the help of experimental studies, such heat exchanger systems are analyzed and corresponding optimization measures are developed.