Residual Oil Aerosol Measurements on Refridgerators and Liquefiers

The purity of the process gas is essential for the reliability of refrigerators and liquefiers. Filtration and adsorption of impurities like water, nitrogen, and oil result in a major effort, cost, and maintenance in the helium process. Expensive impurity monitors for moisture, nitrogen, and hydrocarbon contents are required to identify filter failures and leakage immediately during the operation. While water and nitrogen contaminants can be detected reliably, the measurement of oil aerosols at the ppb level is challenging. We present a novel diagnostic oil aerosol measurement system able to measure particles in the sub amp; 956;m range. This unit enabled us to evaluate and improve the oil separation system on a LINDE TCF 50 helium liquefie