Comparison of Dry Screw Machine and Water Lubricated Air Compressor

Dry oil-free screw air compressor

1. In terms of reliability, the application of dry oil-free screw air compressor has a long history and the technical scheme is very mature. At present, the internationally renowned compressor manufacturers are using dry screw technology to produce pure oil-free compressed air.

2. There are few moving parts in the structure and the structure is simple. The rigidity of the male rotor is higher than that of the female rotor, but the male rotor also bears most of the load, the rigid load ratio of the male rotor is close, and the deformation is uniform. The meshing accuracy is easy to guarantee and the volumetric efficiency is high.

3. In terms of processing technology, the international cutting-edge processing center has large equipment investment, special imported equipment, mature technology, relatively easy processing, easy processing accuracy, and suitable for any environment.

4. Safety: no water is used, there is no problem caused by the introduction of water, there is no problem of water filter blockage, there is no problem of water spray at the air inlet after shutdown, and the two-stage compression technology ensures long-term stable exhaust volume.

5, operation and maintenance: in addition to daily consumables, no other spare parts, saving maintenance costs.

6. Material: The meshing movement is between the rotors, and the instantaneous relative movement direction of the meshing belt is the normal phase (ie pure rolling), there is no friction, and there is no special requirement for the material. There is no friction in the movement of the rotor, and the displacement is stable and will not drop.

7. Bearings: Two-axis motion system requires 8 conventional bearings, and the maintenance and replacement cost is not high.

8. Service life: The rotor is a metal part, which is wear-resistant and has a long service life.

9, compression efficiency: always maintain a high efficiency state, low failure rate, there is no direct friction between the rotor and the rotor casing, the yin and yang rotor deformation is uniform, the failure rate is low.

10, market share: dry oil-free screw compressor is the mainstream product, the annual demand for an average of more than 15% of the scale growth.

Water-lubricated oil-free screw air compressor

1, reliability, the market is common single screw, is only a few small companies developed a small water lubrication model, can not be used in a larger range, due to the immature technology, the use of performance can not be predicted; water only has the cooling effect, and can not achieve the true sense of lubrication.

2. Structurally, there are three rotating shafts, more moving parts, and more complicated structure. The rigidity of the screw and the star wheel is quite different, and the deformation is uneven, so the meshing accuracy is difficult to guarantee, and the volumetric efficiency is slightly lower.

3. In terms of processing technology, there is no precise processing machine tool, and domestic low-precision processing machine tools are used, which is difficult to process and the processing accuracy is not easy to guarantee.

4. Use environment: Because a large amount of water is consumed during operation, it is not applicable in arid and water-scarce areas. In addition, considering the icing problem, it is not applicable in cold areas.

5. Use of pure water resources: High requirements for water quality, need to be replenished regularly, consume a large amount of pure water, have obvious design defects, and long-term water use is not a small expense.

6. Safety: Water quality deterioration is easy to cause corrosion and scaling of the main engine of the compressor, which is easy to cause problems such as the decrease of the efficiency of the main engine and the seizure. The safety accidents caused by water cut-off and water leakage should not be underestimated.

7, water filter clogging: easy to cause insufficient lubrication and exhaust temperature is too high, the water filter also needs to be replaced regularly.

8. Water spray at the air inlet after shutdown: the sealing surface of the water stop valve is worn, and the water stop valve is not closed tightly, which causes lubrication water to spray out from the air inlet and the compressor reverses during shutdown, which is easy to cause mechanical failure of the compressor rotating part.

9, operation and maintenance: many moving parts, high failure rate, high maintenance rate, and the need to replace the star wheel regularly, high maintenance costs.

10. Material: The relative movement of the star wheel and the screw is sliding, and the star wheel is driven by friction. There are special requirements for the material, and no star wheel material that fully meets the requirements has been found. The conventional material used is plastic, which is easy to wear, Deformation and short service life. After running for a period of time, due to the wear of the star wheel, the internal leakage increases and the exhaust volume is reduced. Generally, the exhaust volume is reduced by 5 ~ 10% after 3000 hours, and the exhaust volume is high first and then low, and the performance is unstable.

11. Bearings: There are few manufacturers producing water-lubricated bearings. The three-axis motion system requires 12 bearings, which increases wearing parts and failure points. The price is more expensive and the maintenance and replacement cost is high.

12. Service life: The star wheel is made of non-metallic material, with poor wear resistance, high failure rate and short service life.

13. Compression efficiency: friction, deformation, narrow suction and exhaust channels, large leakage loss between high and low cavities, etc. make the efficiency low. As the running time increases, the star wheel wear will cause the air volume to decrease and the efficiency to decrease. High failure rate, star wheel friction, uneven deformation and insufficient machining accuracy are the main causes of failure.

14, rotor type line: did not find the best type line, did not find the best star wheel material, after use, the exhaust volume decreased seriously, high failure rate, short life.