Liquid ring pumps (ECOVAC)

The liquid ring pump is a rotating machine that uses a liquid to provide a seal between the stator and an eccentric rotor (impeller).
During rotation, the gas admitted between two vanes is compressed by the progressive reduction in volume, generating the desired vacuum level.
The pumped gas/ring liquid mixture is then delivered to a gas/liquid separator.

The vacuum level is limited by the vapour pressure of the liquid making up the ring. This is why LVI SYSTEMS designs complete solutions, integrating complementary technologies such as air ejectors or steam boosters, to optimise performance.

Details Liquid ring pumps (ECOVAC)

The advantages of our ECOVAC liquid ring pumps :
- Possibility of using a ring liquid identical to the process gas (toluene, ethylbenzene, etc.).
- Operates at atmospheric pressure without a recirculation pump.
- Recovery of solvents and alcohols in liquid form.
- Adaptable to all makes (according to customer request).
- High reliability and simplified maintenance.
- Compact dimensions and ready-to-connect delivery.
Our pumps can be fitted with a wide range of options to suit your needs:
- Air ejector for achieving a final vacuum of up to 2.5 mbar abs.
- ROOTS type compressor for a capacity of up to 5000 m³/h and a final vacuum of 0.2 mbar abs.
- Measurement and safety instrumentation.
- Non-return valve with no pressure drop.
- Hydraulic overflow guard.
- Air ejector by-pass valve.
- Condenser and/or active charcoal filter on vent.
Closed-circuit liquid ring pumps

In addition to the liquid ring pump, our closed-circuit pumping units include a separator tank and a heat exchanger.
This configuration greatly reduces, if not eliminates, the need to discharge ring fluid.

Examples of applications
- Closed-circuit pump with double mechanical seals
  Capacity: 250 m³/h of gas (acetone and maleic anhydride), at 50 mbar abs, water-cooled at 5°C.
- Closed-circuit liquid ring pump with decanter
  Separation of pumped solvents from the water in the liquid ring + air ejector.
  Capacity: 115 m³/h of gas containing solvents, at 10 mbar abs, cooled by glycol water at 5 °C.
  The ECOVAC range: zero pollution, high performance
The ECOVAC range: zero pollution, high performance

LVI SYSTEMS has developed the ECOVAC range of liquid ring pumping units designed for :
- Limiting pollution: the closed circuit simultaneously cools the liquid ring and the vent gases, greatly reducing atmospheric emissions (VOCs).
- Improving energy efficiency: vapours are condensed and recovered, limiting losses.
- Optimised reliability: robust, simple design adapted to demanding environments.
Operating principle
- The gases and vapours drawn in are compressed by the pump to atmospheric pressure.
- Mixed with the ring liquid, they pass through a heat exchanger where the vapours condense.
- Condensate and ring liquid are collected by gravity in a separator tank, then reinjected into the pump.
- Only non-condensable gases are vented, limiting pollutant emissions.
Example: for toluene, atmospheric emissions are reduced from 0.1 kg/h to just 0.014 kg/h when cooling is reduced from 20°C to -10°C.