Anti-Fouling Coating for Heat Exchangers

Technology Fouling is the accumulation of unwanted material on solid surfaces causing a detriment of function. It is a global issue that results in costly clean‐up and other related expenses including loss in productivity, increased energy consumption, and pollution to the environment. Various strategies have been developed for reducing fouling in the food industry, including modifying the food equipment surface. However, while many anti‐fouling solutions have been developed and successfully demonstrated in the laboratory, they are typically expensive, not durable, and fail to demonstrate the same benefits under industry comparable process conditions. Researchers from the University of Melbourne have developed a new anti‐fouling surface coating that has been demonstrated in an industrial processing environment to effectively mitigate against fouling and reduce energy costs by 18% while simultaneously increasing capacity by 16%. The anti‐fouling coating is a food grade surface treatment that reduces the rate of fouling build up and increases the heat transfer co‐efficient by 10‐20% compared to an uncoated surface. The process for applying the anti‐fouling coating involves application of two different, water‐based coating layers, which are then cured by heating the exchange surfaces thereby building a smooth hard layer upon the desired surface. The anti‐fouling coating is food‐safe and has been tested under industrial dairy processing conditions on 2‐tonne/hour and 4‐tonne/hour heat exchangers for more than 10 months continuously without observable degradation of the surface. The coating has been applied in‐situ to a variety of different types of heat exchangers, including plate HX, UHT HX, spiral tube, and open boiling pans. This anti‐fouling coating has been tested in Australia, Asia and Europe. The same benefits of direct savings in energy costs and increased production rates have been demonstrated at all sites. The anti‐fouling coating has also been applied to the water cooling system of heat exchangers and demonstrated to reduce or eliminate water scaling.