Alfa Laval – High performance antifouling coating for heat exchangers

A plate heat exchanger is built up of layers of plates made of stainless steel, titanium, or different alloys depending on application. To extend the life span, or the overhaul interval of the heat exchanger, the surface of the plates is treated with an antifouling coating, to prevent or minimize fouling from the fluids used. Depending on the fluids used, different characteristics are asked for on the antifouling coating, but in common, the requirements are:

• Applicable on pressed plates
• Improved corrosion resistance
• Retain thermal efficiency
• Hard, jet flexible surface properties
• Cost efficient (Less than 50€/m2)
• MTTF (Mean time to failure) 20 years

Water, tap water, seawater, chemicals, liquid food, oil are the main fluids used in the heat exchangers. The stainless steel plates are today treated with a flexible ceramic coating with a thickness less than 5 microns. For seawater applications, titanium plates are used. These are expensive, so interesting with a cheaper solution with e.g coated stainless steel.