→Comparison (OIL/Water/Steam)

Screw Type Dry vacuum pump


Water sealed V/P system

1. Cooling water Temp have no effect on vacuum
2. No Vacuum variation during summer time Temp rise.
3. Utility cost 1/2~1/10 than water sealed Vacuum Pump.
4. Suitable for high vacuum (100~10-3 torr)
5. Compare to current systems, more cost will be saved to be bigger capacities.  

1. Pressure varies with Cooling water temperature (in summer)
2. Noise & abrasion due to cavitation (by using air ejector, cavitation is prevented and vacuum efficiency will be improved)
3. Power & cooling water consumption is higher than capacity waste water contamination problem.
4. Capacity limit to low vacuum(200-50torr)
5. Power & investment cost will be much bigger to make big capacity.

Oil Rotary V/P system

1. Screw Type Dry Vacuum Pump (constant vacuum)
2. Suitable for compressde vapor or moistrue
3. No need for oil change (but oil in bearing should be changed every 6 months.)"
4. No contact between rotor and casing, so no wear."
5. Suitable for any capacity(5~300 m3/ min) from low capacity to high capacity.
6. Save 1/2~1/5 of power consumption than oil rotary vacuum pump of same size.

1. Initial vacuum is good, but vacuum varies on process.
2. Condensed vapor and moisture emulsify with vacuum oil & cause process unstable.
3. Vane or piston's abrasion is high. Maintenance is difficult.
4. Frequent vacuum oil change
5. Limit on capacity. Only for small size.
6. Too much power consumption compare to capacity.

Steam Booster system

1. Utility cost 1/10~1/15 of steam booster.
2. Originally eliminate waste water problem
3. Keep constant vacuum and stabilize Process in spite of water Temp. Variation in summer.
4. Small size compare to capacity could save space
5. Easy maintenance.
6. Simple operation due to system automation
7. Easy capacity control & good for high capacity (5~300m3/ min)

1. Too much utility cost. (steam, cooling water)
2. Waste water & pollution problems by using barometric condenser.
3. Cooling water temp. rise during summer (in barometric condenser) result product quality unstable.
4. Need large space for installation compare to capacity.
5. Too much utility costs due to nozzle abrasion for long time use.