Modification of heat exchanger plates for reduced fouling deposition

Flare and frame heat exchangers are frequently installed in processes where formation of deposits on the heat transfer surface cannot be avoided. In this paper the effects of surface energy, wettability and surface roughness on the deposition of calcium sulphate during convective heat transfer to aqueous CaSO4 solutions in plate heat exchangers are studied. The surfaces of several heat exchanger plates have been modified by ion Beam Implantation, Unbalanced Magnetron Sputtering, Mixed Sputtering and Plasma Are Deposition, to reduce wettability and surface energy. Other plates have been electropolished or etched to decrease or increase surface roughness. Fouling experiments with these treated plates and with one set of untreated plates as control have been performed. The results show that hear transfer surfaces with low surface energy, and low surface roughness experienced significantly reduced fouling.