The outlet pipe of the screw air compressor is provided with a check valve, and the high-temperature and high-pressure humid air is discharged through the screw air compressor exhaust valve, and still carries a certain oil and water component after the after-stage cooler. Although the two-stage and three-stage interstage coolers and the final stage cooler of the screw air compressor are equipped with a gas-water separator to separate the moisture generated during the compression process, the actual operation effect is not satisfactory. Because the screw air compressor has a long standby time, the moisture generated by the exhaust gas gathers around the pipeline and the check valve, causing the moisture to flow back to the inside of the casing, and the moisture content of the lubricating oil is gradually increased, eventually leading to the high-pressure screw air compressor oil level alarm and Downtime. When the outlet pipe of the screw air compressor was removed at the stop, it was found that a large amount of milky white liquid flowed out in the pipe, which indicates that the water content of the exhaust air of the screw air compressor was seriously exceeded.
According to the operation requirements of the screw air compressor, the screw air compressor should have a minimum running time to prevent the formation of condensed water, because the condensed water will cause rust in the cylinder valve plate and frame parts. Accumulation of condensate in the crankcase may cause an error in the oil level reading. Water and oil cannot mix, and their co-existence causes the oil to deteriorate quickly. The minimum running time is generally not less than 10 minutes, which should be enough to heat the screw air compressor to the gasification and condensation moisture.