Heat exchanger

The main heat exchanger is the key equipment to ensure the performance of the air separation plant. Its functions in the air separation plant of the molecular sieve pre-filtration process are as follows: recover the cooling capacity of the reflux gas, ensure that the heat exchange temperature difference is within the design range; provide sufficient expansion gas in front of the expander to make up for the cooling loss of the air separation plant; provide raw air for the lower tower under the design conditions; and the working medium is in the main heat exchanger The resistance value in meets the process requirements.

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