Investigation of Polymer Nano-coatings for the Durability Improvement of Heat Exchanger

Abstract

Industries are facing a major problem due to the deposition of the scaling/fouling layer on the plate heat exchanger which directly affects the life expectancy of the heat exchangers. The buildup of scaling/fouling layers over the surface of the heat exchangers also reduces the crosssectional area of the tubes or flow channels, which increases the resistance of the passing fluid. To mitigate the scaling/fouling problem in the heat exchangers, coatings are the prevalent, practical, and preferred method to protect the metals like stainless steel and its alloys from corrosion. In this era, graphene-based organic polymer coatings are widely used as corrosion fortification aids. Graphene has engrossed momentous responsiveness in several industrial fields due to its greater anti-corrosion and barrier properties. In the present study, the graphenebased epoxy polymer coating was applied on SS304 grade using the paint spray technique. Several heat transfer effectiveness experiments were conducted on the heat exchanger test rig. The coatings were characterized using FE-SEM and Raman spectroscopy to confirm the uniform distribution of graphene. Potentiodynamic polarization tests were conducted on the specimen to evaluate the anti-corrosion performance of the coating. FE-SEM and Raman spectroscopy results showed that the spray coating technique is suitable. Electrochemical results reveal that the graphene-based epoxy polymer coating is ~18% less corrosive than the SS304 grade. The incorporation of 0.3 wt.% of graphene into the epoxy coating significantly improved the corrosion resistance and thermal properties.