What is the impact of heat exchanger leakage on distillation columns?

Reply to 1# Gao Jing6522: The methods for checking whether a heat exchanger is leaking can be summarized into three types: 1. Flow rate method. When there is significant leakage between the product oxygen or product nitrogen channel and the air channel, the output of oxygen or nitrogen increases markedly. The air intake volume also needs to be increased. At the same time, the air pressure decreases while the pressure in the upper tower increases. 2. Purity method. If there is a slight leakage between the product oxygen and nitrogen channels and the air channel, this can be determined from the results of analysis on changes in product purity, indicating a decrease in product purity due to the use of a switchable heat exchanger. 3. Temperature method. When a leak occurs between the air channel and the nitrogen waste channel, the temperature will change significantly; it is by observing this temperature change that it can be determined which unit has leaked. Moreover, the amount of air intake will also increase. When there is a severe leak in the main cooler, large amounts of nitrogen at higher pressure enter the oxygen side, causing significant changes in the pressures of the upper and lower columns as well as in the purity of the product, until normal production can no longer be maintained and the plant has to be shut down. When there is a slight leak in the main cooler, it generally does not cause significant changes in the pressures of the upper and lower columns, nor does it lead to a significant decrease in the purity of liquid oxygen inside the main cooler. It is a common phenomenon that there is a large difference in purity between gaseous oxygen and liquid oxygen, with the concentration in the gas phase being lower than the value corresponding to equilibrium with liquid oxygen.