Full-Welded Plate and Shell Heat Exchanger Used as Desuperheater for Waste Heat Recovery

Plate and shell heat exchanger is a heat exchanger with plate tube as a heat transfer element, also known as sheet heat exchanger. It is mainly composed of two parts: plate tube bundle and shell (figure). The contact points of pairs of cold formed slats are tightly welded together to form a plate tube containing a plurality of flat flow channels. Many plates of varying widths are arranged in a certain order. To maintain the distance between the plates and tubes, insert metal strips at both ends of the adjacent plates and tubes, and weld them together. The two ends of the plate tube form a tube plate, so that many plate tubes are firmly connected together to form a plate tube bundle. The end face of the tube bundle presents a number of flat runner plate tube bundle assembled in the shell, and the longitudinal expansion difference is eliminated by sliding seal between it and the shell. The section of the equipment is generally circular, but also rectangular, hexagonal and so on. Fluid A flows inside the plate, and fluid B flows between the plates and tubes inside the shell.

Plate and shell heat exchanger is a structural form between shell and tube heat exchanger and plate heat exchanger, which takes into account the advantages of both:

① With the plate as the heat transfer surface, the heat transfer efficiency is good. The heat transfer coefficient is about 2 times that of shell-and-tube heat exchanger.

② Compact structure, small size.

③ Temperature resistance, pressure resistance, the highest working temperature up to 800℃, the highest working pressure up to 6.3 mpa.

④ The fluid in the flat channel flows at high speed, and the plate surface is smooth, not easy to scale, the plate bundle can be removed, and the cleaning is also convenient. However, the manufacturing process of this heat exchanger is more complicated than that of shell and tube heat exchanger, and the welding amount is large and the requirements are high, so its popularization and application are limited. Shell-and-plate heat exchangers are used in industrial sectors such as chemical, paper, pharmaceutical and food. Typical products are mainly used in food, medicine and other processing industries that require good heat transfer efficiency and short residence time.