The Liquid Condensation Conditions in the Dry Gas Seal System

摘要

Dry gas seal is often used as the seal devices in centrifugal compressor and other high-speed rotating equipment, which requires seal gas clean and dry. If there is some liquid in the seal gas, the dry gas seal will rapidly fail. When the seal gas flows through the filters, valves, orifices, seal faces and so on, the gas temperature will decrease resulted from the Joule-Thomson effect. If the gas temperature is lower than the corresponding dew point, there will be liquid condensation in dry gas seal system. Wet air is taken as an example to show how to calculate the pressure and temperature relationship when it is adiabatic expansion. Dew point lines at different conditions are calculated by considering the vapor-liquid equilibrium. Liquid condensation conditions are acquired by comparing expansion lines and dew point lines, and the factors of influencing liquid condensation were analyzed. The results shows that decreasing gas humidity, increasing the gas temperature can effectively reduce the liquid condensation.