Air sent to the upper column for expansion

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.

A low pressure nitrogen expander is added to the process design. The pressure nitrogen from the pressure tower and high pressure expander is expanded into low pressure nitrogen, which is combined with the nitrogen coming from the low pressure tower and fed into the charge gas compressor. This is specially set up for rapid oxygen load changes. The oxygen product flow rate during normal operation corresponds to the amount of oxygen contained in the amount of air entering the air separation unit. T...