Answer: (1) The function of the air filter. The air filter is a dry paper filter, and its main function is to filter dust in the air.
(2) The function of the intake valve. The loading, unloading and pressure adjustment of the air compressor are achieved by opening and closing the intake valve.
(3) The function of the pressure switch. The intake valve solenoid valve is controlled by the pressure change of the air compressor to open and close the intake valve, and further control the motor. A maximum pressure value can be set. When this pressure value is reached, the intake valve is closed and a shutdown delay signal is sent to the motor. At the same time, another minimum pressure value can be set. When this pressure value is dropped, the intake valve opens or the motor is restarted.
(4) The function of the outlet check valve. After the compressed air enters the gas tank from the compressor, when the compressor stops, the compressed air is prevented from flowing in the opposite direction to the air compressor.
(5) The function of the safety valve. When the pressure switch is improperly adjusted or fails and the pressure in the oil and gas tank is 0.1MPa higher than the rated pressure, the safety valve will open to protect the safety of the air compressor unit.
(6) The role of the pressure maintaining valve (minimum pressure valve). Located at the outlet of the oil fine separator above the oil and gas tank, the opening pressure is set at about 0.45MPa. The functions of the pressure maintaining valve are:
1) Prioritize the establishment of the circulation pressure required for the lubricating oil at startup to ensure the lubrication of the machine body. The machine oil lubrication is carried out by the pressure difference of the machine itself, without the assistance of an additional oil pump. When the machine is in an unloaded state, a certain pressure is still required to maintain the oil circulation, so the air intake valve is relatively closed, and the minimum pressure valve prevents pressure leakage, thus ensuring the circulation of the lubricating oil.
2) When the machine is loading, if the pressure maintaining valve is not installed, the large pressure difference generated before and after the separation of the oil and gas barrel will be added to the separator, causing damage to the separator core; Therefore, the second function of the pressure maintaining valve is to open after the pressure exceeds 0.45MPa, which can reduce the air flow rate flowing through the oil fine separator and protect the oil fine separator from damage due to large pressure difference.
The structure diagram of the pressure maintaining valve is shown in Figure 3-3.
(7) The role of the rear cooler. The outlet temperature of compressed air is lowered by cooling to ensure the safe use of compressed air and meet the performance requirements of air post-processing equipment. There are two cooling methods: air cooling and water cooling.
(8) The role of the discharge solenoid valve.
When the air compressor is shut down or idling, the discharge valve opens to discharge the pressure in the oil and gas tank to ensure that the air compressor can start or run without load when it is running again. Commonly used discharge valves are two normally open solenoid valves or piston-type discharge valves.
(9) The role of the air tank. The air tank is a container for storing compressed air and gas discharged from the compressor. The air tank is conducive to eliminating pulses in the exhaust pipeline and can store and supplement compressed air when the demand is greater than the capacity of the compressor. The larger the volume of the air tank, the longer the compressor operation time interval.
(10) The role of the water-gas separator. The water-gas separator is a device used to collect and remove condensed water precipitated from air or gas during the cooling process.
(11) The role of the automatic drainer. No manual operation is required to drain the condensed water in the gas tank.
See Figure 3-4 for the 15~37kW screw air compressor system flow chart.
Figure 3-4 15~37kW screw air compressor system flow chart
