Waste handling solutions for the refuse derived fuel (RDF) industry - Energy
Waste to energy: The use of refuse derived fuel (RDF) is part and parcel of today`s regulated waste disposal. Using a selective treatment process, fractions high in calorific value are separated off from commercial and industrial waste, creating a marketable product. Depending on calorific value, composition and particle size, this fuel is used in industrial fluidised bed firings, in cement kilns and in RDF power plants.
The right technology
Waste passes through several steps on its way from refuse to fuel. Preshredding brings the input material to a uniform size, which in some cases is already the right size for fuel, and eliminates overlengths which would interfere with further processes. Separation removes contraries and recyclable materials from the fuel fraction. Fine shredding brings the fuel fraction, now free of contraries, to the right particle size. Optional Post-screening makes sure that the particles do not exceed the maximum size for fuel use.
Pre-shredding must bring the input material down to a homogeneous particle size and prevent problematic overlengths for subsequent processing stages. A high level of resistance to contraries is just as important.The single-shaft shredder Terminator addresses these requirements in a perfect way. The highest degree of material opening is achieved using the XXF-shredding unit.
The material flow is diverted into fractions by drum screens or by a ballistic separator. The Ballistor separates into flat, rolling and as two screen fractions, with holes of 0-30 and 30-80 mm for example. Usually the smaller screen fraction is biologically stabilized. The coarse screen fraction enables a saving of fossile fuels when used in fluidized bed incineration plants.
Separation of Recycables
Potential recyclables, or fractions high in calorific value, can be separated off from the rolling fraction for postshredding using inductive and optical sorting systems. After Iron/Non-iron separation the remaining fraction is again fed to the shredder.
The flat, high calorific fraction (calorific value 18-25 MJ/kg) is made up primarily of foil and packaging fractions and is the input material for the last processing step - the post-shredding. Depending on the settings the post-shredder generates both an injectable fraction (< 35 mm) and a particle size (60-100 mm) known as fluidized bed fraction.