Plate vs. shell-and-tube heat exchangers
31 July 2019
Each heat exchange tube of the U-tube heat exchanger is bent into a U shape, and the inlet and outlet are respectively installed on both sides of the same tube sheet, and the head is divided into two chambers by a partition. Each tube is free to expand and contract, independent of the housing. Thereby eliminating thermal stress, the structure is simpler than the floating head heat exchanger. However, the tube process is not easy to clean, and the use has great limitations only for clean fluids.
The plate heat exchanger is composed of a set of rectangular thin metal heat transfer plates, and the plate is clamped and assembled on the bracket by a frame. The edge linings of two adjacent sheets are pressed by gaskets (made of various rubber or compressed asbestos, etc.), and the corners of the sheets have round holes to form a fluid passage.
The difference between the plate heat exchanger and shell-and-tube heat exchanger are high heat transfer coefficient, and the logarithmic mean temperature difference is large and the end temperature difference is small.