…the know-how company
Fields of Application
Simplified it can be assumed that the centrifuge can be used as a substitute for following technologies:
· Hydro cyclones
· Jiggers (à hydro jiggers, hydro concentrating table, hydro through washer)
· Centrifuges - with preceding fine grinding
The application spectrum of the sorting centrifuge is for grain sizes the size of dust upto approx. 120 mm edge length. The density of the “lighter” goods to be feed can range from < 1 kg/dm³ up to > 3 kg/dm³, whereas the density (weight) of the sorting medium with regards to the static as also dynamic burden of the unit is virtually irrelevant.
Depending on the density of the material to be sorted a throughput of 2.0 to 5.0 t per hour can be reached with the smallest standard installation size. With a bigger installation a throughput of up to 40 t per hour can be reached. With a parallel operation in a hall under 400 m² over 350 tons of material per hour can be sorted, which corresponds to an annual throughput (3-shift-operation) of more than 3.000.000 ton.
The density sorting in general and sorting centrifuges in particular are well known techniques in the conventional wet-mechanical processing and recycling. Here different densities of materials are used, to carry out the sorting physically. It has to be distinguished between fluid-fluid-solid or solid-solid-fluid sorting techniques.
Classical procedures for density sorting are static float-sink-units, jiggers, hydro cyclones or the modern sorting centrifuges. Technologically the sorting centrifuge stands in competition with the first named units, the competitors have to be examined in the field of sorting systems.
The professional separation technology for plastic-recycling:
Recycling of mixed plastics,
Oil/fat contaminated plastics and metals,
and each application for separating two materials with a different density.
The sorting results are optimal under the following parameters:
· The density difference of the fractions to be separated is +/- .02 kg/dm³.
· The grain fraction lies between < 1 mm und 40 mm, this means dust and coarse grain.
· The density of the sorting medium (e. g. water) lies between the density of the fractions.
· The suspension ratio (sorting medium to fraction) is bigger than 1:40.
The centrifuge has a vertical working rotor with continuous output for heavy and light fraction (Ø 1200 mm x 500 mm ),
Process Principles Centrifuge
Basis of the procedure is the physical behaviour of solids with different densities in a liquid. In conventional float-sink-basins the natural gravitational forces often are not sufficient for a quick and safe separation of heavy and light fractions (SF; LF). Through the rotation speed an accelerating force respectively a centrifugal force builds up in the centrifuge, which exceeds the gravitation force hundredfold. This force is ideally adjusted to the input material as also to the used sorting medium and secures a quick and clean sorting of the material at a stable operating process.
Process Plan and Data
The rotor (1) accelerates to the desired rotational speed and the sorting liquid is added through the input port (11 to start up). At the discharge jigs light fraction (2) and heavy fraction (3) a continuous ventilation is built up by reducing the number of revolutions of the stripping blade (4) the (brake motor). The process stabilizes itself within seconds. The suspension (solid-solid-liquids-mixture) is fed through the input port (5 sorting process) and cannons onto the driving plate (6), which rotates with the same speed as the liquid column (7).
By entering into the liquid column the solid waste mixture is swirled in the liquid. The light solid particles are immediately washed to the surface (8), flow upwards to the discharge light fraction (2) and then are washed out through an outlet pipe. The heavy fraction penetrates into the water column, cannons onto the rotor wall (9), due to the conical cut of the drum (as also gravitation) it is forced downwards and is then wrenched to the discharge due to a difference in the flow rate (suction). The heavy fraction gets washed out through the inner shaft (10).
At the outlet there are worm conveyors (with draining device, automatic drying) with which the gravitational turbidity can be fed in a circuit.
The professional separation technology for the bulk industry:
The working princip of "ConCENT" is similar to "ReCENT ". The differences are just the size and drive parameters.
The coal, iron and steel industry, as well as the mining and metallurgical industry are regarded as future principal users of the centrifuge. In the area of plastic recycling there are detailed disquisitions regarding the possible fields of application, which cover complete work concepts.
Concrete fields of application of the centrifuge technology in the coal, iron and steel industry are:
Coal preparation Large-size material (10 mm < x < 120  mm )
Fine grade sorting ( .5 mm < x < 10 mm)
Finest grade sorting (< .5 mm)
Bauxite preparation Separation of the Al2O3 (after jaw- and hammer crusher
(with ~ 50 mm) soil, earth and silicic acid during the refining (washing).
Other ore’s and minerals in the region of up to < .1 mm like iron ore, tin ore etc. fluor spar, barium, kaolin and various ores as also mineral sludges
Steel production blast sludge processing
Aluminum production aluminum recycling
The fields of application include the aspects of purity and volume reduction, whereas from the total input value also an arbitrary grain size can be processed as component flow, where high standards are expected in the quality (purity) or loss in output.
Other fields of application like oil sand, processing of mud (deep bore engineering), sedimentation mud or retreat of landfills are momentarily not under discussion.
Holger Schoenebeck ** Roder 15A **D-19230 Moraas **Tel.: +49(0) 38 83 51 06 02 **Fax: +49(0) 38 83 51 01 48