Vacuum technology
Liquid Ring
Water-sealed, vapour-tolerant, rugged.
Schematic section, not to scale
How it works
Liquid ring pumps use a rotating ring of liquid, usually water, to seal and compress gas. They tolerate wet, dirty and vapour-laden gas streams and are common in paper, chemical, power and mining.
An eccentrically mounted impeller throws service liquid against the casing, forming a ring. The spaces between impeller blades and the ring expand and contract as the impeller turns, drawing in and compressing gas.
Performance range
Typically to roughly 30-150 mbar(a); lower with staging or ejectors
Typical industry range. Exact capability is model specific, see each model’s curve.
In the catalogue · 269 models from 11 manufacturers
- Pumping speed
- 5.9 – 26,800 m³/h · 220 models
- Ultimate pressure
- 1.3 – 160 mbar · 203 models
- Motor power
- 0.4 – 800 kW · 193 models
- Weight
- 17 – 12,800 kg · 177 models
- Noise level
- 70 – 90 dB(A) · 117 models
- Max. pressure
- 0.1 – 2.21 bar · 26 models
Spread of each model’s own rated figure, as published by its manufacturer.
Advantages & tradeoffs
- Handles liquids and vapours
- Few moving parts
- Near-isothermal compression
- Service liquid consumption and treatment
- Ultimate vacuum limited by liquid vapour pressure
- Larger footprint
Best applications
Common in Food + Beverage, Plastics, Pharmaceutical, Chemical, Oil + Gas, Power Generation, Pulp + Paper, Water + Wastewater, Mining.
Maintenance
Service liquid management, seal and bearing service, strainer and separator cleaning.
Energy characteristics
Specific-energy comparisons (kW per unit of flow at your operating point) appear here as sourced performance curves are added. Until then, compare models directly on the Performance Map.
Open the Performance Map