Water ring vacuum pump is a positive displacement pump, which is characterized by pumping volume and speed is proportional to the working point of shaft power and its speed is proportional to the power of 1.7. That is, when the water ring vacuum pump is determined, can adjust the speed to adjust the pumping capacity. If the inverter can be used in 0.5 ~ 100Hz can be adjusted within the characteristics of continuous speed, you can 2 times the motor rated speed range to adjust the pumping capacity. Compressor air compressor energy loss is the main mechanical losses, the loss of compressed air waste, air compressor operating loss of air load, compressed air flow losses and other losses. When the air compressor output pressure is greater than a certain value, some paper companies or automatically open the unloading valve, the asynchronous motor idling, a serious waste of energy, or downtime.