1. Comparison Ejectors - Vacuum pumps
Basic design of an ejector
Design of the complete system
Example: comparison of air flow / energy consumption
Comparison of different working principles
Extract from „Druckluft effizient“

2. Basic design of an ejector5 6 1 4 2 3
1 Compressed air
2 Nozzle
3 Suction pipe
4 Vacuum connection
5 Inlet filter
6 Exhaust air

3. Basic design of a multi-stage ejector (company PIAB)
1 Compressed air
2 Nozzles
3 Suction pipes
4 Vacuum connection

4. Complete system of an ejector
Compressed-air reservoir
Oil separator
Compressor 6 bar
Cooling dryer
Ejector
Inlet Filter

5. Complete system of an ejector
The ejector has no energy consumption  The compressor has a very high energy consumption (Compressed air is expensive energy)
The ejector is maintenance-free  The compressor station is very maintanance-intensive (Most common are oil-lubricated screw-compressors with half-yearly maintenance)
The ejector has no heat convection  The compressor (often in separate room) has the heat convection. Also the exhaust air of the ejector affects its surrounding of the production machines  Anyhow the vacuum pump can be installed in a separate room as well or the outgoing air can be ducted out of the machine

6. Complete system of the ejector
The ejector requires no space  The compressor station requires much more space than the vacuum pump
The ejector is oil-free  The compressor is mostly oil-lubricated and the compressed air requires an intensive filtration (oil separator, cooling dryer)
The exhaust air of the ejector is cold  The cooling dryer cools the compressed air of the compressor, the exhaust air of a vacuum pump can be cooled by a heat exchanger as well

7. Complete system of the ejector
Ejectors do have a high efficency  Compressed air is „expensive energy“  Refer to the comparison of the different working principles
Ejectors have short evacuuation and reaction times  The times of evacuation and reaction are much shorter with vacuum pumps
Ejectors are very safe in operation  The operating safety depends on the complete system, not only on the ejector

8. Example
Ejector Type M100L (PIAB) Vacuum pumps Types KVT 3.60 and VT 4.16 (BECKER)
BECKER KVT 3.60
PIAB M 100 L
BECKER VT 4.16

9. Example: Comparison of air flow
Ejector Type M100L (PIAB) Vacuum pumps Types KVT 3.60 and VT 4.16 (BECKER)
Data from Becker data sheet Data from PIAB data sheet

10. Example: Comparison of air flow
BECKER KVT Hz BECKER VT 4.16 PIAB M 100 L

11. Example: Comparison of energy consumption
Ejector Typ M100L (PIAB) Vacuum pumps Types KVT 3.60 and VT 4.16 (BECKER)
Data from Becker data sheet Data from PIAB data sheet
* 2,5 6 bar compressed air = 1 KW (Reference: Internet Atlas Copco)

12. Example: Comparison energy consumption
BECKER KVT Hz BECKER VT 4.16 PIAB M 100 L

13. Example: Saving of energy
Difference = Saving: (4,8 - 0,43) KW = 4,37 KW
4,37 KW x 0,1 €/ KWh* = 0,44 €/h
0,44 €/h x 16 h / day** = 7,04 €/day
7,04 €/day x 250 days / year = €/year
* 1 KWh = 0,1 €
** 2-shift-operation

14. Comparison of different working principles
Oil-free rotary-vane-vacuum pump VTLF 250 (Becker)
Multi-stage sidechannel-vacuumpump COVAC 300 (Rietschle Thomas)
2-stage Side channel vacuum pump SV 5.690/2 (Becker)
Ejector EJ V 864 (with 6 bar compressed air) (PIAB)

15. Comparison of different working principles Intake flow rate / Vacuum

16. Comparison of different working principles Power consumption / Vacuum

17. Comparison of different working principles Efficiency / Vacuum

18. Additional informationen from: www.druckluft-effizient.de
The working group ”Druckluft effizient“ would like to inform plant engineers and users of compressed air about the possibilities to save costs and energy as well motivate the users to realize the potential savings.
The different ways to optimize the technical applications of compressed air from the planing to processing and from distributing to and financing will be identified and then will be shown in so called ”fact sheets“.
Additional informationen from:

19. Extract from the factsheet ”Applications“ of