Energy saving and emission reduction of air separation equipment

Why is there coexistence of liquid nitrogen and gaseous nitrogen in fractionator of air separation equipment?

When the main condenser evaporator leaks seriously, a large amount of high-pressure nitrogen will leak to the low-pressure oxygen side, and the pressure of the upper and lower columns and the purity of the product will change significantly until normal production cannot be maintained. When the main condenser evaporator leaks slightly, the pressure of the upper and lower columns will not change significantly, and the purity of liquid oxygen in the main condenser evaporator will not decrease significantly. The common phenomenon is that the purity of the gas and liquid oxygen in the main condensing evaporator is very different, and the gas concentration is lower than that in equilibrium with liquid oxygen. For example, the concentration of liquid oxygen is 99% and that of gaseous oxygen is 96%, that 7 main cooling pipes were found to be leaking during maintenance. The common causes of leakage are as follows: 1. Pipes are worn due to mutual vibration. For long tube condensing evap