Welded plate heat exchangers cut refinery process costs-Part 2

摘要

Plate-and-frame(P&F)heat exchangers were first manufactured 100 yr ago for use in the dairy industry.They have since been used in the process industries,as they offer considerable advantages in true counter-current flow,high heat transfer rates,low manufacturing costs and a small footprint.These benefits lead to lower capital and operating costs than can be achieved with shell-and-tube(S&T)heat exchangers.The limitation on their use has been the elastomer gasket between each plate,which is susceptible to leakage from chemical attack or to penetration by aromatics.In addition,operating pressure and temperature are typically limited to 20 bar at 180°C(356°F)for water-a condition that precludes its use in many downstream processes,especially refining,where aromatics can soften gasket materials at considerably lower temperatures.