Vacuum Belt Filter

Vacuum Belt Filter

The vacuum belt filter (VBF) is used for the filtration of liquids and dewatering of sludges. Unlike hydrostatically working filters, the filtration is made by gravity with additional vacuum support. As a result, higher throughputs and better dewatering of the filter cake can be achieved. Depending on the application, filter fleeces or endless filter belts are used.

In many applications, the vacuum belt filter provides an effective
alternative to belt filter presses or chamber filter presses as well as
centrifuges.

Function

vacuum-belt-filter_cross-section_480px

The untreated water is fed into the filter from the top and is spread evenly over the entire filter belt width via the inlet box (❶). The filter belt is fed below the water level (❷). Here, in the lower parts, the filtration process takes place while further up there is the dewatering of the filter cake. Via a side channel compressor (❸) air is sucked off continuously from the filter chamber (❹), whereby a slight vacuum is created on the side of the filtrate. As soon as the liquid level exceeds a certain level, the vacuum is broken and the filter belt clocks on. The resulting filter cake is separated from the tape by a scraper (❺). The belt is then cleaned with a brush roller (❻) and rinsed with additional high-pressure flushing  nozzles (❼).


Fields of Application

Vacuum belt filters are suitable for liquids that are recirculated
because there are no chemical changes of the medium due to exclusively
physical filtration. A combination of filtration and sludge dewatering
on one device is possible for small amounts of waste water.

  • Metal processing industry
    e.g. filtration of coolant lubricants, decreasing baths, washing water and process water
  • Gravel and sand industry
    e.g. sludge dewatering from washing water treatment
  • Steel industry
    e.g. dewatering of scale sludges that accrue in the treatment of
    cooling water from rolling or continuous casting
  • Recycling industry
    e.g. filtration and dewatering of washing water from recycling
    of electronic scrap, car shredder or plastic; treatment of washing
    water from waste incineration slags
  • Natural stone industry
    e.g. filtration and dewatering of grinding water when cutting
    and processing natural stone
  • Food processing industry
    e.g. sludge dewatering of vegetable washing water
  • Municipal waste water treatment
    e.g. thickening of sewage sludge before digestion tank,
    dewatering of sewage sludge


Often the vacuum belt filter is combined with a lamella clarifier, since
the sludge can be led directly from the lamella separator to the vacuum
belt filter for further dewatering without intermediate buffer.

Further examples and applications can be found in our references:

Advantages

Advantages of the vacuum belt filter:

  • High throughput and dewatering performance due to
    vacuum support and inclined belt position

  • No consumables through endless filter belts

  • Optimum utilization of the belt: floated material is removed
    together with the sediment on the discharge side

  • Filtrate can be used for rinsing the belt

  • Resistant to fluctuating inlet conditions

  • Low investment and operating costs compared to
    other sludge dewatering technologies such as centrifuges
    and chamber filter presses

Leiblein vacuum belt filter – everything's clear!

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further information.

Solution examples

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examples and reference constructions.

Pilot Plants

Customer-specific pilot
plants for testing purposes.