Wet separators or wet scrubbers are used for exhaust air purification in industry and are used to filter dust, chips, aerosols and other particles from contaminated process air. In contrast to dry extraction, wet extraction uses water as the filter medium. The pollutants and particles are sucked into the extraction system by the process air, where they are bound and separated by the water. HEPA H14 filters are used as a second filter level against carcinogenic dusts and fine dusts, which can also filter viruses, pollen and mold spores. The cleaned process air can either be fed back into the production hall in recirculation mode or discharged outside as exhaust air.

In wet separators, water is used to separate dust, chips and other particles. The water acts as a filter, as the particles from the polluted process air combine with the water droplets. The air is first drawn through a fan into a water vortex, a water wall or a water basin and then passes through further filter stages in the extraction system. All ABSAUGWERK wet separators have a specially developed stainless steel metal mesh in the second filter stage which separates the moisture from the cleaned air. When processing carcinogenic substances such as stainless steel dust, we use a HEPA H14 filter as a third filter stage. This also filters out fine dust and particles down to a size of 0.001 µm, including viruses, pollen or mold spores, extremely effectively.

The areas of application for wet separators are as varied as the technologies. Not every wet separator is equally suitable for all types of dust, powder or chips. When selecting the right dust extraction solution, we take numerous parameters into account in order to guarantee you an economical and sustainable extraction system.

• Flammable dusts
• Explosive dusts
• Stainless steel dusts/steel dusts
• Chips
• Metal dusts (aluminum, magnesium, titanium)
• Plastics, rubber
• Fibers, lint
• Wet dusts
• Sticky powder

Wet separators are particularly suitable for filtering flammable, explosive, sticky, fibrous or moist media (dusts, fibers, powders, etc.). The filter medium water extinguishes sparks and reduces fires or dust explosions. Special ATEX directives (ATmosphères EXplosibles) apply to industrial extraction systems, which require a special design and technical components.

Wet dust extractors are used in a wide range of industries for production processes such as grinding, polishing, cutting and slicing.

The operation of wet separators in Germany is regulated by the 42nd Ordinance on the Implementation of the Federal Immission Control Act (42nd BImSchV) from 2017. This regulation was supplemented by the VDI 3679 guideline of the VDI/DIN Commission. This legal situation results in a number of obligations for operators of wet separators, particularly with regard to the process water for filtering in exhaust air operation.

Before a system is put into operation, an independent risk assessment including action plans must be carried out by a hygiene expert if limit values are exceeded.

• The operator is obliged to keep a logbook with documentation of the samples.
• Regular laboratory tests must be carried out, including verification.
• A reference value for germ contamination must be established and adhered to.
• The unit must be inspected at least every 5 years by an expert or an accredited inspection body.

Note: The 42nd BImSchV only applies to exhaust air operation. The water in recirculation mode should always be tested regularly, as legionella can form and endanger employees.

Cleaning:
To ensure constant separation performance and avoid deposits, wet separators should be cleaned regularly depending on the degree of soiling. Various inspection openings and a cleaning set with hose are available for this purpose.

Maintenance:
At least annual maintenance of your extraction systems is recommended in order to meet the requirements of product safety and the Ordinance on Industrial Safety and Health.

Disposal:
Wet separators use water as the main filter medium, although some products have additional filter stages. The contaminated process air is drawn through the exhaust system and filtered by water. Light suspended matter and particles remain in the water, while coarser particles sink to the bottom and are disposed of as sludge discharge. The less residual water there is in the discharge, the less expensive it is to dispose of. Our sludge tanks therefore contain a sieve with filter fleece that separates the water from the sludge.

Numerous parameters must be taken into account for the selection of the ideal dust removal system. The decision between a wet separator and a dry separator depends on various factors:

• Material composition and quantity of the extracted medium
• Carcinogenic, flammable or explosive substances
• Daily operating time/shift operation
• Sparks
• Flammable or explosive dusts
• Required air volume and extraction power
• Energy consumption and operating costs
• Capture and discharge system

Depending on the manufacturer and product, the filter medium in wet separators consists of a water basin or water vortex and other filter stages. The costs for replacement filters are partially eliminated due to the use of water, but the disposal of the sludge is significantly more expensive compared to dry dust. When buying, it is advisable to look out for washable filter media such as stainless steel mesh filters.

Explosion protection for extraction systems:
Wet separators are particularly suitable for environments with flammable and explosive dusts or processes with a high level of flying sparks. The water filter medium can reduce potential fires or explosions at an early stage. Only a few manufacturers also offer ATEX dry deduster.

• Wash tower / packed column
• Jet scrubber (exhaust gas cleaning)
• Vortex wet separator
• Rotary wet separator
• Venturi wet separator
• Bypass channel scrubber

Our Series B wet separators work with a specially developed channel bypass with innovative flow division, for which a patent application has already been filed. Thanks to the intelligent division of the air flow, the wet separators from ABSAUGWERK consume significantly less energy and water, while at the same time increasing suction power by 50%.