How Many Passes for the Shell and Tube Heat Exchanger?
The number of passes refers to the tube side fluid. The shell and tube heat exchanger is commonly made in single pass, two pass and four pass configurations, although custom multipass heat exchangers with yet another number of passes are also available. A U-tube heat exchanger is automatically a two pass heat exchanger, because of the heat exchanger tube U turn as shown in the diagram above. The first image in this article is a straight tube, two pass heat exchanger. Instead of a U-tube bundle, the end channel and an internal horizontal baffle, are used to cause the two passes. A schematic diagram for a straight tube, one pass heat exchanger is shown in the previous section.
