1. The reason and preventive measures of oil injection (commonly known as oil vomiting) of the screw air compressor host.
Cause analysis:
The oil injection of the screw air compressor refers to the oil injection of the air inlet of the air compressor. Generally occurs in the sudden shutdown, such as the air compressor motor power loss or manual emergency shutdown, at this time the air compressor suddenly shutdown and did not open the discharge valve in time to discharge the air compressor oil and gas barrel residual gas, if the intake check valve is too late to close, the air compressor inlet is injected with lubricating oil.
Troubleshooting / preventive measures:
First, check that the broken oil solenoid valve has no fault. If it is normal, it should further check whether the check valve on the main exhaust pipe can be closed in time or closed completely. If any, any fault should be removed. At present, the double screw air compressor is generally no longer installed broken oil solenoid valve, so the main reason for oil injection is that the check valve is not closed.
Once the power is off, the solenoid valve action, the intake valve closed, initial isolation, but there are generally air holes or gaps on the intake valve, can not be completely isolated from the outside, for the butterfly intake valve, the heavy hammer check valve feel the pressure change, emergency closure, this is the most effective and the last measure to prevent oil spitting. At present, the double screw air compressor generally does not install broken oil valve, after shutdown through the check valve partition, pressure to the oil of the oil in the machine internal pressure into zero, gravity back to oil and gas barrel, the heavy hammer check valve is the most effective way to prevent oil, but now some small models usually use piston type intake valve (or lift valve), with spring control piston to play the dual role of intake regulation and check, over time, piston wear is inevitable, shutdown spit oil will happen, is normal shutdown stop oil phenomenon.
2. Reasons and treatment methods for not loading the screw air compressor.
Fault phenomenon:
The air compressor start the air valve can not open.
The possible causes include:
(1) Pressure switch failure;
(2) Solenoid valve failure;
(3) Poor injection valve lag action;
(4) The discharge solenoid valve failure;
(5) Poor operation of the pressure maintenance valve;
(6) Control the gas source pipeline leakage.
Troubleshooting:
Check, repair or replace for the above possible causes.
3. The reasons and treatment methods for not unloading the screw air compressor.
Fault phenomenon:
The air compressor continues to operate after exceeding the set pressure and cannot be unloaded Vehicle, or continue to rise to the safety valve action.
The possible causes include:
(1) The pressure switch is not set properly or the drift occurs after setting (the controller fault);
(2) The inlet valve is not poor, and it causes failure or incomplete movement;
(3) When the system stops using gas, if the discharge solenoid valve fails, the pressure will rise slowly;
(4) Failure of the control loop.
Troubleshooting:
Check, clean, repair and replace if necessary.
4. Reasons and treatment methods of frequent addition and unloading of screw air compressor.(Power frequency machine)
The possible causes include:
(1) The pressure difference between the upper and lower limits of the pressure setting is too small;
(2) There is more leakage in the gas pipeline or equipment;
(3) The pressure maintenance valve seal is not strict, the spring fatigue;
(4) The upper pressure limit is set too low;
(5) The pipe filter on the exhaust pipe of the air compressor is seriously blocked;
(6) Check valve is installed on the outlet pipe of the screw air compressor.
Troubleshooting:
Reset the pressure difference between the upper and lower pressure above 0.2MPa, consider increasing the capacity of the gas storage tank, eliminate leakage, adjust or repair the pressure to maintain the valve spring force. The pressure maintenance valve of the screw air compressor is equivalent to the check valve. If there is a check valve on the outlet pipeline, the pressure detected by the pressure sensor of the air compressor is actually a small pressure of the pipeline. If the pressure maintenance valve of the air compressor leaks slightly to the oil and gas barrel, the pressure detected by the pressure sensor will drop, causing the reloading of the air compressor.
5. Reasons and treatment methods for screw air compressor for a long time.
The possible reason is the fault of the time relay. The screw compressor is generally set for 15~20min after the empty motor motor stops running. If the motor is not stopped, the time relay and control circuit should be checked and replaced if necessary.
