The efficiency for direct drive and gear drive are as high as 98%~99%, and belt drive's efficiency ranges from 94% to 98%.
2. No Load Energy Consumption
When chooses gear drive, no-load pressure of 2.5 bar, sometimes even 4 bar, should be ensured in order to make sure the lubrication of gearbox. But when chooses direct drive or belt drive, no-load pressure, theoretically speaking, could be zero, because the oil absorbed by rotors could lubricate the bearing and rotor already. But for safety's sake, a pressure of 0.5 bar is always ensured.
Take a 160kw gear-driven air compressor for example, it works 8,000 hours in a single year, but 15% of them (about 1,200 hours) are in no-load condition. Thus, 28,800 kwh's electricity pricing will be extra charged when compared with same power air compressors with a belt or direct drive, suppose these two kinds of air compressors – gear driven one and belt/direct drive one- own a pressure difference of 2 bar (about 15% energy consumption difference). In the long term, it will be a large amount of money.
3. Design pressure difference
With the improvement of manufacturing technique, the air compressor we bought earlier could not support our requirement, sometimes higher and sometimes lower. So changing its pressure becomes quite necessary.
But if your air compressor is gear driven type, changing its pressure is quite a hard and expensive work.
If yours is a direct driven one, it will be much easier.
However, if yours is a belt drive one, all you need is to change its belt wheel and belt.
4. Maintenance cost
All the screw air compressors utilize circular shaft seal, which needs to be changed when used for a certain period of time.
For gear-driven air compressor, only when motor and coupling are separated first, could shaft seal could be changed. It cost a large amount of human effort and time, so the maintenance cost is quite high. But for belt-drive or direct-drive air compressors, maintenance staffs only need to disassemble the coupling and belt wheel, which is quite simpler.
Meanwhile, when there is any damage for motor or rotor bearing, related key components will be damaged directly or indirectly, while it never happens for direct-drive air compressor or belt-drive air compressor.Technical Parameters
|FAD/Discharge pressure m³/min/MPa||3.8/0.7||5.3/0.7||6.8/0.7||7.4/0.7||10.8/0.7||13.8/0.7||16.5/0.7||21/0.7||24.1/0.7||28.7/0.7||32.0/0.7||36.7/0.7||43.0/0.7|
|Lube-oil amount L||18||32||65||90||100|
|Power supply V/ph/HZ||380/3/50|
|Outlet pipe diameter Inch||G1||G1½"||G2"||DN65(cold water pipe diameter G1½")||DN80(cold water pipe diameter G2")||DN100(cold water pipe diameter G2")|
Jufeng is an industrial air compressor manufacturer and mainly offers rotary screw air compressors. Besides the JF direct drive rotary screw air compressor, we also provide ADF and ODF air compressors. We offer wide range of compressors like two stage air compressor, belt drive air compressor, variable speed drive rotary screw compressor for customers.