Answer: The main engine of air compressor is the core part of air compressor, which is in high speed operation for a long time. Because the components and bearings have their corresponding service life, preventive overhaul must be carried out after running to a certain time or number of years. In summary, the main overhaul work should be carried out for the following items:
(1) Clearance adjustment.
1) The radial clearance between the Yin and Yang rotors of the main engine increases.
The direct consequence is that the compressor leakage in the process of compression (i.e. back leakage) increases, and the volume of compressed air discharged from the machine becomes smaller.
Reflected in the efficiency of the compression efficiency of the compressor is reduced.
2) the gap between the Yin and Yang rotor and the rear end cover and bearing increases, which mainly affects the sealing and compression efficiency of the compressor, and has a great impact on the service life of the Yin and Yang rotor. The rotor clearance is adjusted to avoid scratches or abrasion of the rotor and the shell during overhaul.
3) There may be strong friction between the screw of the main engine, between the screw and the front and rear end faces, between the screw and the housing of the main engine, and the motor will be in overload working state, which will seriously endanger the safe operation of the motor.
If the electrical protection device of the air compressor unit is not sensitive or ineffective, it may also lead to the motor burning down.
(2) wear treatment.
As we all know, as long as the machinery is in operation there is wear, under normal circumstances because of lubrication fluid lubrication, wear will reduce a lot, but long-term high-speed operation, wear is slowly increasing.
Screw air compressors generally use imported bearings, and their service life is limited to about 30000h.
As far as the main engine of air compressor is concerned, in addition to bearings, there are also wear of shaft seals and gearboxes.
If minor wear does not take correct preventive measures, it is easy to lead to wear and tear, causing damage to components.
(3) Host cleaning.
The internal parts of the main air machine are in the environment of high temperature and high pressure for a long time, coupled with the high-speed operation, and there will be dust and impurities in the ambient air. These fine solid substances enter the machine, along with the carbon accumulation of lubricating oil, if they form a larger solid block over a long period of time, it may lead to the main engine stuck.
(4) Increased costs.
Here costs refer to maintenance costs and electricity costs.
Because the main air compressor has not been overrepaired for a long time, the wear of parts increases, and some worn impurities remain in the main engine chamber, which will shorten the life of lubricating fluid. At the same time, due to impurities, the service time of oil and gas separator core and oil filter is greatly shortened, resulting in an increase in maintenance costs.
In the aspect of power cost, the increase of friction and the decrease of compression efficiency will inevitably lead to the increase of power cost.
In addition, the decrease of air volume and compressed air quality caused by the main air compressor will also lead to the indirect increase of production costs.
In summary: normal mainframe overhaul is not only the basic requirement of equipment maintenance, but there are serious safety risks in extended 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 air compressor host machine on time and in accordance with the standards.