ABSTRACT
A typical double-pipe heat transfer exchanger consists of one pipe placed concentrically inside another pipe of a larger diameter with appropriate fittings to direct the flow from one section to the next, as shown in Figures 1.8 and 6.1. One fluid flows through the inner pipe (tube side), and the other flows through the annular space (annulus). The inner pipe is connected by U-shaped return bends enclosed in a return-bend housing. Double-pipe heat exchangers can be arranged in various series and parallel arrangements to meet pressure drop and MTD requirements. The major use of the doublepipe heat exchanger is for sensible heating or cooling of process fluids where small heat transfer areas (up to 50 m
) are required. This configuration is also very suitable for one or both of the fluids at high pressure because of the smaller diameter of the pipes. The major disadvantage is that they are bulky and expensive per unit of heat transfer surface area.
