Technology
Liquid ring vacuum pumps
The technology for humid and wet processes: a ring of operating liquid seals the chambers of the impeller. 208 current models from 4 manufacturers ā comparable by pumping speed, ultimate pressure and rated motor power.
Compare 208 modelsHow the technology works
- 208models
- 17series
- 4manufacturers
- 25 mbarlowest ultimate pressure
Touch the points: the parts explain themselves.
Manufacturers and series
4 manufacturers, 17 series
Each series leads to its page with all models. āShow only ā¦ā sets the filter of the product overview.
Atlas Copco
75 models Ā· 25ā36,600 mĀ³/h
Busch
70 models Ā· 25ā16,160 mĀ³/h
Edwards
42 models Ā· 20ā8,100 mĀ³/h
Elmo Rietschle
21 models
Product overview
Compare all 208 models
The filters on the left narrow down the selection by the key figures of the models ā for 50 or 60 Hz.
Atlas Copco AWC A series 8 models
Atlas Copco AWC series 9 models
Atlas Copco AWD A series 8 models
Atlas Copco AWD series 14 models
Atlas Copco AWL series 11 models
Atlas Copco AWS series 22 models
Atlas Copco LRP VSD+ series 3 models
Busch DOLPHIN series 70 models
Edwards EHR/SHR series 9 models
Edwards LR1A series 12 models
Edwards LR1C series 9 models
Edwards LR1D series 12 models
Elmo Rietschle L-BL2 series 7 models
Elmo Rietschle L-BV2 series 4 models
Elmo Rietschle L-BV3 series 1 model
Elmo Rietschle L-BV5 series 5 models
Elmo Rietschle L-BV7 series 4 models
No model matches these filters.
Atlas Copco AWC A series 8 models
Atlas Copco AWC series 9 models
Atlas Copco AWD A series 8 models
Atlas Copco AWD series 14 models
Atlas Copco AWL series 11 models
Atlas Copco AWS series 22 models
Atlas Copco LRP VSD+ series 3 models
Busch DOLPHIN series 70 models
Edwards EHR/SHR series 9 models
Edwards LR1A series 12 models
Edwards LR1C series 9 models
Edwards LR1D series 12 models
Elmo Rietschle L-BL2 series 7 models
Elmo Rietschle L-BV2 series 4 models
Elmo Rietschle L-BV3 series 1 model
Elmo Rietschle L-BV5 series 5 models
Elmo Rietschle L-BV7 series 4 models
Models that a manufacturer no longer carries in its current range are not part of this overview; they are listed in its āOutdated modelsā section ā for example under outdated Edwards models.
Operating principle
How a liquid ring vacuum pump works
The impeller sits eccentrically in the pump housing and turns without touching it ā it is the only moving part. The rotation presses the operating liquid against the housing wall as a ring; this ring seals the chambers between the blades from one another. Because the impeller sits eccentrically, the chambers first grow and then shrink again with every revolution.
The drawing shows the basic principle. The designs of the individual manufacturers differ in detail.
- SuctionThe gas flows through the inlet connection (A) and the suction port (B) into a chamber (E) that grows as the impeller turns.
- CompressionOn the other side the liquid ring (D) penetrates the chambers again: they shrink and the gas is compressed.
- DischargeThe gas and part of the operating liquid leave the pump through the discharge port (F) and the outlet connection (G).
Key figures
The technology in figures
The ranges result from the current models in our range.
Pumping speed (50 Hz)
20 to 36,600 mĀ³/hin our range
Ultimate pressure
25 to 160 mbarin our range
Rated motor power (50 Hz)
0.3 to 800 kWin our range
Ultimate pressure compared (mbar, logarithmic)
For comparison: the oil-lubricated rotary vane vacuum pumps in our range reach 1 Ć 10ā»Ā³ to 20 mbar.
What characterises the technology
One moving part
The impeller is the only moving part inside and turns in the housing without contact.
Operating liquid
For stable operation, liquid must be supplied to the pump continuously. It forms the sealing ring and is expelled again with the gas.
Recirculation operation
A recirculation unit returns the expelled operating liquid to the pump. The pump then needs considerably less fresh liquid.
Humid processes
Liquid ring vacuum pumps are used mainly in humid and wet processes ā depending on the version, with corrosion-resistant materials such as stainless steel or ceramic.
Advantages
What speaks for this technology
- Suitable for humid and wet processes
- Only one moving part inside
- Impeller runs without contact
- Constant operating characteristics
- High abrasion resistance
- Corrosion-resistant materials, depending on the version
- Quiet running
Applications
Where they work
- Food and beveragesdairy industry, filtration systems, water degassing, preservation, sugar production
- Packaging machinesfilling and sealing machines, blister machines, filling of PET bottles
- Ceramics and bricksdegassing of ceramic bodies
- Water and environmentwater degassing, groundwater lowering, seawater desalination, sewage treatment plants
- Textiles and tobaccoyarn steaming, tobacco humidification
- Further applicationsdrying systems, central vacuum systems, steam turbines, lifting and handling
Frequently asked questions
Questions about liquid ring vacuum pumps
How does a liquid ring vacuum pump work?
An impeller that sits eccentrically in the housing turns in a ring of operating liquid. The ring seals the chambers between the blades; because the impeller sits eccentrically, the chambers grow and shrink again with every revolution ā the gas is drawn in, compressed and expelled. The drawing in the section Operating principle shows every step.
What ultimate pressure do liquid ring vacuum pumps reach?
The models in our range state ultimate pressures from 25 to 160 mbar. The value that can be reached also depends on the vapour pressure of the operating liquid ā in the case of water, that is, on its temperature. In the product overview, the āUltimate pressureā filter narrows down the selection.
Why does the pump need operating liquid?
The operating liquid forms the ring that seals the chambers. Because part of it is expelled with the gas, liquid has to flow in continuously ā as fresh liquid or via a recirculation unit that returns the expelled liquid to the pump.
From which manufacturers does Ehrler & Beck carry this technology?
Currently from Atlas Copco, Busch, Edwards and Elmo Rietschle. The series are listed in the section Manufacturers and series.
How do I find the right model?
In the product overview, the filters narrow down the selection by the key figures of the models. For sizing, it is best to tell us the gas to be conveyed, the working pressure and the flow rate you need ā we will be glad to advise you.
What do the figures for 50 Hz and 60 Hz mean?
Flow rate and rated motor power depend on the mains frequency. The overview therefore shows both values wherever the manufacturer states them, and the size filters can be switched between 50 Hz and 60 Hz.
Does Ehrler & Beck also supply spare parts and service?
Yes. Ehrler & Beck offers original spare parts and accessories as well as maintenance and repair.
Which model fits your process?
Tell us the gas to be conveyed, the working pressure and the flow rate you need ā we will advise you on selection, spare parts and service.
