Large air separation nitrogen production units

1. Before connecting the pipe orifice of each container, clean white cloth shall be used to tie the orifice to prevent grease and dirt from entering. 2. When welding in the cold box and in the condensing evaporator, it is strictly forbidden for flame or arc to touch the surface of vessels and pipes. 3. The containers, valves, pipes and corresponding supports in the cold box, the surface of the cold box and the foundation surface shall not be stained with grease after installation, otherwise, degreasing treatment shall be carried out.

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