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The Wet Shredding Dry Downstream System has been developed to meet the stringent environmental pressures now placed on processors, whilst continuing to maintain clean, good commercial quality, frag and non-ferrous products.
The overriding principal of the system is the combination of the controlled mill water injection system with a high efficiency air cleaning module.
The water injection system is designed to add controlled amounts of water into the mill in proportion to the loading on the shredder at any one time.
This is achieved by sensing the mill motor current and feeding this signal into a Programmable Logic Controller (PLC).
The PLC then controls a pump and linear valve so that the water entering the mill body is proportional to the mill current and hence the load on the shredder.
The water is introduced into the body of the mill in a specific position, chosen to achieve maximum atomisation and effect of the water, whilst minimising the potential damage to the injector pipes and avoiding any difficulties during maintenance duties.
Hence steam is immediately produced within the mill from the heat of the shredding operation.
No Free Water is created with all its associated problems.
Further controls are added into the PLC program and thus the quantity of water injected into the shredder is in proportion to:-
- The volume of material being shredded.
- The climatic/weather conditions at the time of shredding.
- The existing moisture content of the material being shredded.
Air cleaning and magnetics are then used to separate the ferrous, non-ferrous and dirt fractions.
The air-cleaning module consists of one plenum (an expansion chamber) and either two or four cyclones (dependant on the plant production rate) which separate the dirt fraction from the airstream, the whole system is powered by a high efficiency fan.
The effect of the water injection system, in combination with the air cleaning module, is to create steam within the shredder to coagulate the micron sized dust into larger particles, which can then be effectively removed from the airstream within the two cyclones.
The major benefits of the system are detailed in our brochure The Environmental Concept of Shredding.
Click here to request a copy of our brochure
The combination of the controlled water injections into the shredder and the efficient air-cleaning module provide many benefits, both commercial and environmental, to the Scrap Processor.
The main benefit is in terms of dust emissions from the system to atmosphere.
R.E.D. Ltd can guarantee dust levels in the air from the fan chimney to be less than 10mg/m³
This figure is well below any current environmental limit on emissions set throughout Europe.
- Suppressed fires and explosions within the shredder.
- Reduced shredder dust emissions.
- Reduced conveyor transfer point dust creation.
- Reduced capital and operating costs when items of plant such as mill extraction systems, wet arresters, venturi scrubbers and other filters are removed from an existing downstream system.
- Clean, commercial quality, products.
- The system is compatible with any manufacture of shredder.
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