Deep cooling air separation process

Under the conditions of certain welding methods, welding materials, welding specification parameters and welding structure, the difficulty of obtaining high-quality welded joints is called steel weldability. Therefore, the weldability should be evaluated from two aspects of manufacturing and application. The weldability of process mainly refers to the possibility of various cracks in welded joints, which reflects the difficulty of manufacturing. Weldability of using mainly refers to the mechanical properties and special properties of heat resistance, corrosion resistance, low temperature resistance and fatigue resistance of welded joints, which reflects the reliability of use.

Shell and tube air separation heat exchanger is the most representative wall heat exchanger. It has a long history of application and is still dominant in all heat exchangers. Shell and tube heat exchanger is mainly composed of shell, tube bundle, tube sheet and head. Most of the shell is round, and there are parallel tube bundles inside. Both ends of the tube bundle are fixed on the tube plate. In shell and tube heat exchanger, there are two kinds of fluids for heat exchange. One kind of fluid flows in the tube, and its stroke is called tube side. The other flows outside the tube and its stroke is called shell side. The wall of tube bundle is the heat transfer surface. In order to improve the heat transfer coefficient of the fluid outside the tube, a certain number of transverse baffles are usually installed in the shell. The baffle can not only prevent the short circuit of the fluid and increase the velocity of the fluid, but also force the fluid to flow through the tube bundle man