Getting Shredder Emissions Under Control

SICON (Germany) is considered the leading supplier of sustainable and economical solutions for scrap treatment and processing as well as re-utilisation of resulting residues. Globally, customers benefit from the innovative solutions developed by the SICON team, based on the patented VW-SICON process. Less known however is the fact that SICON also offers state-of-the art solutions for waste air treatment for large shredder plants, either as modules for retrofitting or as turnkey systems for new installations.

Emissions of large shredder plants are under scrutiny by environmental authorities and often also give rise to problems in terms of acceptance. While in many regions worldwide, shredder plants operate without any waste air treatment at all (water injection only) and the waste air is released into the environment without any treatment, in Europe and Japan at least, shredder emissions are collected and cleaned for many years already. Generally, this is done via a combination of cyclone and washer separation. Dust emissions are reduced to values of <50 mg/m³ for older or < 10-20 mg/m³ for newer installations. Gaseous emissions are only collected and reduced to a limited degree and thus, as a result emissions such as VOCs (Volatile Organic Compounds) and PCBs (Polychlorinated Biphenyle) are not captured by existing installations. In Europe, the legal limit of 50 mg/Nm³ VOC is thus normally only achieved with clean scrap. However, a shredder can only make use of its economical benefits and technological superiority once also contaminated scrap and composite materials can be processed, which are not suitable for scrap shears or other processing methods without material separation or which do not guarantee appropriate metal recovery. SICON can offer systems for emission reduction tailored to the requirements of this sector, which can then be customized to meet the demands of the individual operation.

For existing installations with cyclone/washer separation, SICON, a systems supplier, offers to optimise these systems to meet state-of-the-art requirements.

SICON's program range includes modern water circulation systems for retrofitting which guarantee improved filtration results. The rotation screens with downstream water treatment, mostly the so-called sludge trap, almost exclusively in use today, are considered very susceptible to malfunctions and less efficient.

SICON filters the washing water up to < 20 µ, resulting in an improved washer efficiency. At the same time, the wear costs for all wetted parts are considerably reduced.

For further reduction of emissions, SICON offers a graduated system which, depending on dust loading, can reduce PCB emissions to <0.1 ng TEQ/Nm³ (TEQ=Toxic Equivalent) and VOC emissions to < 20 mg/m³.

An innovation is the dry waste air treatment developed by SICON. A combination of the SICON Pre-Shredder EcoRip, modified shredder control and very controlled water injection allows SICON to make do without the Venturi scrubber. Cyclone separation with intelligent explosion protection as well as a downstream dry filter with adsorption additive and precoating result in a decisive reduction of the emissions. A final carbon filter ensures safe adherence to even the strictest VOC and PCB limits. And all this at reduced investment and operating costs.