What does it mean for a screw air compressor to operate in unload mode?
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What does it mean for a screw air compressor to operate in unload mode? What does it mean to uninstall and run? How is unloading during operation controlled?
Unloading begins once the set pressure limit is reached. For example, if the set pressure range is 0.6–0.7 MPa, the compressor starts to load when the outlet pressure is below 0.6 MPa, and it starts to unload when the pressure exceeds 0.7 MPa; in other words, the motor stops operating.
Primarily, when the exhaust pressure of the screw compressor unit reaches the set value, it will operate in unloaded mode, which saves electricity and energy. If the unit operates in this unloaded mode for 50% of the time, it indicates that the selected model is too large.
There is a load/unload valve, similar to a butterfly valve, installed on the pipeline at the compressor inlet. When the back pressure reaches the unload pressure, the valve closes (it has small holes, so it doesn’t close completely), thereby preventing the compressor from delivering air downstream and keeping it in a no-load state