Study On Growth And Cleaning Of Protein Fouling On Heat Exchanger Surface And Anti-fouling

In the process of industrial production,heat exchangers are widely used for pasteurization and sterilization purposes,but the fouling,formed on the surface of heat exchangers in the process of using,have a very serious effect on heat exchanger performance.Heat exchanger fouling caused numerous cleaning cost,affected the service life of heat exchanger,influenced the economic benefit of the factory,and even involved food safety and so on.Moreover,heat exchanger fouling is a complex physical and chemical process,which is the result of the comprehensive action of energy transfer,momentum transfer and mass transfer.There are many influencing factors,which have not been solved effectively so far.In dairy industry,protein fouling is an important factor on the performance of heat exchangers.So it is of great significance to study the growth and cleaning of heat exchanger surface fouling.A real-time monitor system on fouling on heat exchanger was used in present work to investigate the growth and cleaning processed of protein(whey protein concentrate(WPC)and soy protein isolate(SPI))fouling on heat exchanger under different conditions.In the fouling processing,at a certain protein concentration,the effects of heat flux,the inlet temperature and the flow rate of protein solution on protein fouling quality,fouling morphology,surface temperature of heat exchanger and heat transfer coefficient were investigated.Under the same experimental condition and protein concentration,fouling and cleaning behavior of soy protein isolate(SPI)was very different from that of whey protein concentrate(WPC).Under certain experimental conditions,SPI fouling are easier to clean.In addition,the effects of different coatings on protein fouling and cleaning process were discussed.Different coating materials were used to modify the heat exchanger surface,including hybrid coatings(Fluorolink?S10/TEOS=70/30),Fluorolink?S 10 coatings,Ni-P-PTFE coatings and SupBor coatings,and the effect of different coatings on protein fouling and cleaning process was also investigated.The results showed that Ni-P-PTFE coating had an anti-fouling effect on whey protein concentrate.The hybrid coatings(Fluorolink?S 10/TEOS=70/30)and Fluorolink?S 10 coatings had no effect on the growth of WPC fouling;However,they increased the cleaning efficiency of fouling.The SupBor coating has little influence on the fouling process and the cleaning processing of fouling.By changing the stainless steel surface with hybrid coatings(Fluorolink?S10/TEOS=70/30)and Fluorolink?S 10 coatings,the cleaning efficiency of fouling can effectively be increased,and the phenomenon has very important significance.