Air compressor: screw air compressor principle and common troubleshooting methods
Air compressor: compressed air is one of the important media of our factory. It is mainly used as the anti-blast energy of dust collector. Dust collector, as environmental protection equipment, is an important equipment needed for production and the normal operation of the whole factory related to its normal operation. I plant air compressor station a total of five compressors, three laps two. In operation, due to the environment, temperature and other reasons on site, screw air compressor failure, affecting the normal production supply. Common problems must be solved to ensure the normal operation of air compressors through continuous learning. So, let's understand the principle of screw air compressor and common fault solutions!
First, the working principle of screw air compressor
1. The basic process of air compressor
2. Parts introduction
1) Air filter
The main function of air filter is to remove dust in the air. Accuracy of air filter: 98% for 1 meter, 99.5% for 2 meters, 99.9% for 3 meters. When the pressure difference of air filter reaches -50mbar or 4000 hours, blow back or replace. Please avoid inhaling acid mist, oil mist and oil mist. The life of air filters varies with the operating environment.
2) the unloading valve
The function of the unloading valve is to open and close the amount of inhaled air according to the needs of the amount of inhaled air. The air compressor in the open state of the unloading valve is the load, and the air compressor in the closed state of the unloading valve is the unloading, and the unloading is controlled by the electromagnetic valve. Unloading valves require maintenance every 8000H of operation.
3) the screw
The screw is the heart of the compressor. Screw compressor is a volumetric compressor, the amount of gas produced by screw compressor is related to the speed. The outlet temperature of the injection screw head needs to be <120℃. The life of the injection screw is related to the quality of lubricating oil, and the correct use and maintenance.
4) Oil cut-off valve (fuel cut-off valve).
When the fuel cut-off valve works, it will cut off the oil supply from the lubricating system to the screw when it stops, preventing the lubricating oil from ejecting from the air filter after stopping. The fuel cut-off valve is fully open when unloading and closed when stopping. The fuel shutoff valve will affect the oil supply to the rotor, resulting in trip at high temperature, so it needs to be fully opened during unloading. Fuel shutoff valve is serviced once at 8000H.
5) Oil temperature valve
The function of the oil temperature bypass valve is to adjust the oil temperature, ensure the viscosity of the oil, ensure the lubrication effect. The nozzle temperature valve is generally 40-60, the oil supply system with the oil temperature below 40 is a small cycle, and the oil supply system with the oil temperature above 60 is a large cycle. In order to prevent water in the lubricating oil, the high-temperature temperature valve is selected. Oil temperature valve maintenance time is 8000H.
6) Oil and gas separator
The function of an oil-gas separator is to separate oil and gas. The normal operating pressure difference of the oil and gas separator can be dangerous if it is used continuously for 1.0bar or for more than 8000H. The life of oil and gas separator is disposable and cannot be cleaned.
7) Oil cooler/post cooler
Oil coolers are used to cool lubricating oil, and rear coolers are used to cool compressed air. Poor cooling effect will affect the normal use of air compressor. Keep the surface of cooler clean and clean regularly. Do not use pickling when cleaning the cooler. Water-cooled machines should pay attention to the requirements of water quality, water pressure, temperature and flow, and install prefilters at the water inlet.
8) Place the electron trap (EWD) in
The principle of the electron trap is to use an electrostatic capacitance sensor in the collector to change the capacitance according to the change of liquid level. When the liquid level in the collector reaches a certain height, the electronic processor sends a signal to start the solenoid valve. The solenoid valve is energized, the displacement of the valve body, and the condensate water in the collector is discharged from the discharge outlet. Close the solenoid valve after the liquid level in the backwater bend drops horizontally. Electronic traps malfunction, and the fault signal sends an alarm through the computer.
Two, screw air compressor routine maintenance
1. Daily work content: check the level of compressor oil; Check the monitor and dashboard readings. Check for condensate discharge during loading. After stopping, drain condensate from air and rear cooler.
2. Weekly work content: Check the set value in the program; If a tank is installed, drain the condensate; Investigate the possibility of leaks.
3. Work content every six months: remove the air filter, spray high-pressure air for cleaning, check whether there is any damage: clean the compressor.
4. Annual work: replace the ventilation filter of the gear box; Replace the filter for indicator light/display test; When using mineral oil, replace the oil; Replace the air filter; Test the relief valve.
3. Common faults and solutions of screw air compressor
1. Air compressor head temperature is too high to cause skip: because the ambient temperature is too high to cause skip, it is necessary to improve the ambient temperature and reduce the ambient temperature through reasonable ventilation device improvement; Because the lubricating oil position is not normal, the temperature difference of the oil cooler that ensures the normal lubricating oil position is not normal, so the oil cooler should be checked. The temperature difference between the lubricating oil before and after the oil cooler must be about 18. When the temperature difference is too low, clean the oil cooler. When the temperature difference is too high, it means that too little oil has passed through the cooler. Check whether the oil line is blocked. If the oil is blocked, replace the oil cooler. Check whether the constant temperature valve is working properly; Check whether the fuel cut-off valve works normally; When the unloading temperature is too high, check whether the control air path of the oil is leaking or the foundation oil pressure is too low.
2. The oil content at the outlet of air compressor is high (under normal circumstances (2-3ppm)). First, the exhaust pressure of air compressor must be above 4Bar; With paper cup or glass sampling judgment, there are roses on the water is normal, oil content is too high when there is oil; Check whether the oil level is too high, whether the lubricating oil is dirty; Check whether the return pipe is blocked, eccentric or too short; Check whether the one-way valve on the return pipe is blocked or in the opposite direction; Check whether the return hose passes through the bottom of the rotor; Check whether the gas separator diversion cover is damaged; Check the oil and gas separator for damage.
3. Water is contained in the lubricating oil of the injection screw machine. Unload unit for a long time, adjust air usage, increase compressor loading time; Constant temperature valve failure, constant temperature valve maintenance or replacement; Cooling water temperature is too low, shall not use frozen water; Water cooler leaks. Repair or replace the water cooler.
4, nozzle outlet oil content is high) oil level is too high, oil into the standard height; The oil temperature is too high, check the temperature control valve, cooling water, cooling water pressure, oil cooling efficiency; The 2 mm hole of the return tubing is blocked for dredging; Bending or deviation of the return pipe, adjusting or replacing the return pipe; Replace the oil and gas separator when it is damaged.
5. Air compressor is not loaded: when the solenoid valve works, it will lead to mechanical failure. Determine whether there is 10% control gas. If not, check whether the smaller pressure valve has gas leakage, whether the gas pipe is blocked, whether the gas leakage; The solenoid valve does not operate when electrical failure occurs, the solenoid valve is damaged, repair the solenoid valve, or reconnect because of poor contact.
The above is the principle of screw air compressor and common fault solutions, if you need to know more, you can contact us at any time!
Shijiazhuang Compus Compressor Co., Ltd. main products are oil-free air compressor, high pressure air compressor, screw air compressor, air compressor, drilling air compressor, oil-free mobile machine, high pressure mobile machine, drilling machine, two-stage compression screw machine, permanent magnet variable frequency screw machine, mine explosion-proof screw machine, air floating centrifugal blower and so on. At present, the company has established 30 customer service networks and more than 100 dealers in the country, to provide customers with pre-sales technical consultation, machine sales, on-site maintenance, parts supply 4S services. The enterprise's good faith service is well received by users. Adhering to the core concept of "quality first, customer satisfaction", we always adhere to provide customers with high-quality products and technical services, we firmly believe that Compus will become your more reliable partner, and are willing to work with you to achieve glory!