2BV Liquid Ring Vacuum Pump Applications

Why the Wet-Gas Advantage Matters in Application

Many vacuum processes pull air together with solvent vapour, water vapour or process moisture, and evaporating, drying and filtering duties routinely condense part of that vapour inside the pump. A dry mechanical vacuum pump must be protected from that liquid, which can wash away lubrication, attack internals or cause seizure; a liquid ring pump absorbs the condensate into the sealing water and carries it away, so wet gas is handled rather than resisted.

Small entrained droplets, foam carry-over and minor particulate are tolerated for the same reason — the liquid ring continuously renews itself — which is why the 2BV vacuum pump is the workhorse of industrial vacuum wherever the gas is never quite clean or dry. Compression is also nearly isothermal because the ring absorbs the heat of compression, useful for temperature-sensitive vapours.

Core Applications of the 2BV Liquid Ring Vacuum Pump

Each application below relies on one capability: stable vacuum with a wet stream at the inlet.

Vacuum filtration and cake dewatering

In a drum, belt or tilting-pan filter, the pump holds a steady vacuum that pulls filtrate through the medium while the cake builds. As the cake thickens and resistance rises, the pump keeps drawing air through the wet filter — a duty hard on dry machines because filtrate vapour and liquid slugs cross the inlet.

Vacuum distillation and solvent recovery

A column under vacuum lowers boiling temperatures so heat-sensitive products can be distilled safely. Solvent vapour that reaches the pump condenses as compression raises pressure and temperature; the liquid ring tolerates that condensable load, which makes the 2BV a standard fit for solvent recovery and for chemical and pharmaceutical vacuum processes where reactors and dryers emit vapour and droplets.

Vacuum degassing and de-aeration

Edible oils, resins, transformer oil and process water are held under vacuum so dissolved gases leave solution and are swept away. Vacuum impregnation uses the same pump to evacuate a chamber before sealant is drawn into porous parts such as motor windings and castings.

Paper machine forming section

On the wet end of a paper machine, vacuum drains and dewaters the sheet on the forming fabric and conditions the felts. The air drawn is humid and fibre-laden — exactly the service a liquid ring pump absorbs without complaint.

Food packaging vacuum

Chamber and modified-atmosphere packaging lines evacuate pouches and trays before sealing, often in humid surroundings with product dust in the air. The water-sealed 2BV keeps working where an oil-sealed or dry pump would not last.

Sealing Water Temperature: The Hidden Control Variable

The achievable vacuum is set less by the impeller than by the sealing-water temperature: warmer water has a higher vapour pressure, which raises the minimum pressure the ring can pull. Rated performance assumes sealing water at or below 30°C; in warm climates or once-through water systems, a heat exchanger or cool make-up supply is usually needed.

Anti-Cavitation Protection Below 80 mbar

As inlet pressure approaches the vapour pressure of the sealing water, the ring flashes locally and the pump cavitates, producing noise, vibration and impeller pitting. For inlet pressures below about 80 mbar — close to the 0.097 MPa absolute ultimate vacuum — fit the manufacturer-recommended anti-cavitation protection pipe, which feeds a controlled gas flow to suppress cavitation.

Model selection — flow at the working pressure, sealing-water circuit and wetted materials — follows the duty, and the 2BV liquid ring vacuum pump selection guide walks through that process step by step.

Liquid Ring or Dry Vacuum Technology?

Where the gas is genuinely clean and dry and a deeper vacuum is needed, a dry claw pump competes: it runs oil-free, reaches about 1 mbar absolute and needs no sealing water — but it cannot accept liquids or condensable vapour, the very thing the 2BV handles best. Matching technology to vapour load is the core of industrial vacuum pump selection; where both could work, compare the claw pump against the 2BV package on utility, sealing-water and maintenance costs.

Frequently Asked Questions