A scrap metal shedding operation required a customised dust extraction solution that could manage the high volumes of dust generated from the by-product waste, carpeting and insulation that is attached to the metal being processed, particularly when working with metal from wrecked cars and household appliances.
Kooltron fabricated and installed a plant that uses a venturi water scrubber to wash the dust from the air that is being extracted off the shredder.
- The dust-laden air initially passes into a 1380mm diameter cyclone that is 5410mm in height and manufactured from 5mm steel. A 900mm x 600mm rotary valve is fitted below the cyclone to allow the cyclone to operate effectively while under negative pressure.
- The bulk of the larger dust particles are collected via the cyclone.
- The finer dust particles are washed out of the air stream at the venturi scrubber and transported via piping to a settling tank that is combined with a sludge ejector.
- The dirt collected in the settling tank is constantly removed for disposal by the rotating paddles of the sludge ejector.
- A large droplet eliminator vessel, 2060mm diameter x 7090mm high and manufactured from 5mm steel is located after the venturi washer to prevent water droplets being drawn through the system.
- The fan: A 1000mm diameter backward curved centrifugal fan with a single inlet is located after the droplet eliminator. The fan is directly driven by a 160kW 380V 4-pole motor that is connected to the fan impeller via a coupling.
- A welded and bolted steel support structure accommodates the cyclone, the venturi scrubber and droplet eliminator as well as the maintenance walkways, which are located at three different levels. Cat ladders provide access to the individual walkways – and all walkways and ladders are fitted with handrails, kickplates and safety cages respectively.
Kooltron manufactured the steel support structure and entire plant in Cape Town and installed it in East London using locally sourced specialised cranes and transport.
Environmental benefit: The water is constantly recycled to prevent wastage and pollution of nearby water resources.