The working process of screw compressor

(1) Expansion: When the piston moves to the left, the volume of the cylinder increases, the pressure drops, and the remaining gas originally remaining in the cylinder continues to expand.
(2) Suction: When the pressure drops to slightly less than the gas pressure in the intake pipe, the gas in the intake pipe will push the suction valve into the cylinder. As the piston moves to the left, the gas continues to enter the cylinder until the piston moves to the left end (also known as the left dead center).
(3) Compression: When the piston turns the direction to the right, the volume of the cylinder is gradually reduced, so that the process of compressed gas begins. Because the suction valve has a check effect, the gas in the cylinder can not be poured back into the inlet pipe, and the gas pressure in the outlet pipe is higher than the gas pressure inside the cylinder, and the gas in the cylinder can not run from the exhaust valve to the outside of the cylinder. The gas in the outlet pipe can not flow into the cylinder because the exhaust valve has a reverse effect. Therefore, the amount of gas in the cylinder remains certain, because the piston continues to move to the right, reducing the gas space (volume) in the cylinder, so that the pressure of the gas continues to rise.
(4) Discharge: As the piston moves to the right, when the pressure of the compressed gas rises to slightly greater than the gas pressure in the outlet pipe, the gas in the cylinder will top the spring of the exhaust valve into the outlet pipe, and continue to discharge until the piston moves to the right end (also known as the right dead point). Then the piston starts to move to the left again, and the action is repeated. The piston constantly reciprocates in the cylinder, so that the cylinder reciprocates the suction and discharge of gas. Each reciprocation of the piston becomes a working cycle, and the distance passed by the piston each time it comes or comes back is called the stroke.