The precautions in the maintenance of screw air compressors are finally understood!
Precautions in the maintenance of screw air compressors.
1. Explain the maintenance method of screw air compressor rotor
During the overhaul of the screw air compressor, it is inevitable to find problems such as wear and corrosion of the rotor. Generally speaking, even if the twin-screw head has been used for more than ten years (as long as it is used normally), the wear of the rotor is not obvious, that is to say, its The efficiency drop will not be too great.
At this time, it is only necessary to polish the rotor slightly for inspection and maintenance of the rotor; collision and strong disassembly cannot occur during disassembly and assembly of the rotor, and the dismantled rotor should be placed horizontally and securely.
If the screw rotor has been severely worn, that is, the exhaust volume caused by leakage can no longer meet the user’s gas consumption requirements, it must be repaired. The repair can be done by spraying and screw machine tools.
But since most service providers do not provide these services, it is difficult to complete. Of course, it can also be repaired by hand after spraying, which requires knowing the specific profile equation of the screw.
A module is processed for manual repair, and a set of special tooling is designed to complete the repair work.
2. What should be paid attention to before and after the maintenance of the screw air compressor?
1. Before maintenance, stop the operation of the unit, close the exhaust valve, disconnect the power supply of the unit and put up a warning sign, and vent the internal pressure of the unit (all pressure gauges show “0″) before starting maintenance work. When disassembling high-temperature components, the temperature must be cooled to the ambient temperature before proceeding.
2. Repair the air compressor with the correct tools.
3. It is recommended to use special oil for screw air compressors, and it is not allowed to mix lubricating oils of different brands after maintenance.
4. The original spare parts of the air compressor are specially designed and manufactured. It is recommended to use authentic spare parts to ensure the reliability and safety of the air compressor.
5. Without the permission of the manufacturer, do not make any changes or add any devices to the compressor that will affect the safety and reliability.
6. Confirm that all safety devices have been reinstalled after maintenance and before start-up. After initial start-up or electric control system inspection, before starting the compressor, it must first be confirmed whether the rotation direction of the motor is consistent with the specified direction, and the tools have been removed from the compressor. Walk.
3. What does the minor repair of the screw air compressor include?
There is only a general distinction between minor repairs, medium repairs and major repairs of air compressors, and there is no absolute boundary, and the specific conditions of each user unit are also different, so the divisions are different.
The content of general minor repairs is to eliminate individual defects of the compressor and replace individual parts, including:
1. Check the carbon deposition of the rotor at the entrance;
2. Check the intake valve servo cylinder diaphragm;
3. Check and tighten the screws of each part;
4. Clean the air filter;
5. Eliminate air compressor and pipeline leakage and oil leakage;
6. Clean the cooler and replace the faulty valve;
7. Check the safety valve and pressure gauge, etc.
4. What is included in the medium repair of the screw air compressor?
Medium maintenance is generally performed once every 3000-6000 hours.
In addition to doing all the work of minor repairs, medium repairs also need to disassemble, repair and replace some parts, such as dismantling the oil and gas barrel, replacing the oil filter element, oil and gas separator element, and checking the wear of the rotor.
Disassemble, inspect and adjust the thermal control valve (temperature control valve) and pressure maintenance valve (minimum pressure valve) to restore the machine to normal operation.
5. Briefly describe the reasons and necessity of the periodic overhaul of the main engine of the screw air compressor
The main engine of the air compressor is the core part of the air compressor. It has been in high-speed operation for a long time. Since the components and bearings have their corresponding service life, they must be overhauled after a certain period of time or years of operation. In general, the main Overhaul work is required for the following:
1. Gap adjustment
1. The radial gap between the male and female rotors of the main engine increases. The direct consequence is that the compressor leaks (ie, back leak) increases during compression, and the volume of compressed air discharged from the machine becomes smaller. In terms of efficiency, the compression efficiency of the compressor is reduced.
2. The increase of the gap between the male and female rotors, the rear end cover and the bearing will mainly affect the sealing and compression efficiency of the compressor. At the same time, it will have a great impact on the service life of the male and female rotors. Adjust the rotor gap for overhaul to avoid the rotor and The casing is scratched or scuffed.
3. There may be strong friction between the screws of the main engine and between the screw and the housing of the main engine, and the motor will be in an overloaded working state, which will seriously endanger the safe operation of the motor. If the electrical protection device of the air compressor unit responds insensitively or fails, it may also cause the motor to burn out.
2. Wear treatment
As we all know, as long as the machine is in operation, there is wear and tear. Under normal circumstances, due to the lubrication of lubricating fluid, the wear will be reduced a lot, but the long-term high-speed operation will gradually increase the wear. Screw air compressors generally use imported bearings, and their service life is limited to about 30000h. As far as the main engine of the air compressor is concerned, in addition to the bearings, there are also wears on the shaft seals, gearboxes, etc. If the correct preventive measures are not taken for minor wear, it will easily lead to increased wear and damage to components.
3. Host Cleanup
The internal components of the air compressor host have been in a high-temperature, high-pressure environment for a long time, coupled with high-speed operation, and there will be dust and impurities in the ambient air. After these fine solid substances enter the machine, they will accumulate day by day along with the carbon deposits of the lubricating oil. If it becomes a larger solid block, it may cause the host to be stuck.
4. Cost increase
The cost here refers to maintenance cost and electricity cost. Due to the long-term operation of the main engine of the air compressor without overhaul, the wear and tear of the components increases, and some worn impurities remain in the cavity of the main engine, which will shorten the life of the lubricating fluid. The time is greatly shortened, resulting in increased maintenance costs.
In terms of electricity cost, due to the increase of friction and the decrease of compression efficiency, the electricity cost will inevitably increase. In addition, the decrease in air volume and quality of compressed air caused by the main engine of the air compressor will also increase the production cost.
To sum up: the normal main engine overhaul work is not only the basic requirement for equipment maintenance, but there are serious safety hazards in overdue use. At the same time, it will bring serious direct and indirect economic losses to production.
Therefore, it is not only necessary but also necessary to overhaul the main engine of the air compressor on time and according to the standard.
6. What does the overhaul of the screw air compressor include?
1. Overhaul main engine and gear box:
1) Replace the rotating bearing of the main engine rotor;
2) Replace the main engine rotor mechanical shaft seal and oil seal;
3) Replace the main engine rotor adjustment pad;
4) Replace the main engine rotor gasket;
5) Adjust the precision clearance of the gearbox gear;
6) Adjust the precision clearance of the main engine rotor;
7) Replace the main and auxiliary rotating bearings of the gearbox;
8) Replace the mechanical shaft seal and oil seal of the gearbox;
9) Adjust the precision clearance of the gearbox.
2. Grease the motor bearings.
3. Check or replace the coupling.
4. Clean and maintain the air cooler.
5. Clean the maintenance oil cooler.
6. Check or replace the check valve.
7. Check or replace the relief valve.
8. Clean the moisture separator.
9. Change the lubricating oil.
10. Clean the cooling surfaces of the unit.
11. Check the working conditions of all electrical components.
12. Check each protection function and its setting value.
13. Check or replace each line.
14. Check the contact condition of each electrical component.