The Contraplex is a fine impact mill with two driven pin discs. In counter-rotating mode, much higher relative speeds are possible than with the UPZ fine impact mill with only one driven pin disc. The highest relative speed develops at the outermost pin rows and can be up to 240 m/s.
The fineness can be adjusted by altering the pin disc speeds. The centrifugal forces acting on both discs ensure that even moist, greasy and sticky products can be processed. The design with the wide-chamber housing is ideal for processing these kinds of products. The feed material is often embrittled by intensive mixing with liquid nitrogen.
The mill door can be hinged opened wide to permit easy cleaning.
The CW wide-chamber housing prevents coating formation and thus blockages in the machine. In comparison with the pin disc Ø, the machine housing is oversized. This is why Contraplex mills are ideal for fine grinding greasy, oily, sticky and hygroscopic materials which tend to form deposits - either in continuous mode or at relatively long cleaning intervals. Besides the wide-chamber housing, the rotation of both pin discs (both speed and rotational direction are adjustable) is a distinguishing feature. The following important application advantages result:
- Wide selection of pins: Besides the standard head pin made of special steel, there is a wide selection of special pins available which make it possible to meet the highest demands regarding hygiene, wear reduction and contamination risks.
- Robust drive solution: The belt drive via standard motors permits optimum configuration of the transmission ratio for the process and the product. This means that the motor and pin disc work at the optimum operating point and the system achieves a much higher degree of energy efficiency than with direct drives.
- Bearing unit: The optimum monitoring of bearing temperature and vibrations translates into excellent preventative maintenance. In addition the two bearing units of the CW II are identical, and easy and fast to change.
- Higher grinding fineness: Dependent on the type, the max. relative speed of both discs is up to approx. 240 m/s. Single-rotor pin, beater, cross-flow and turbo mills, etc. are unable to reach this high speed. The Contraplex therefore produces higher fineness values - especially with all brittle and crystalline materials. Individual adaptation of the grinding conditions to suit the feed material. The wealth of possibilities available in setting the rotational direction and disc speed combinations ensures that each and every product - especially heat-sensitive ones - is ground to an optimal fineness, is handled gently and that the pin discs remain free from deposits.
- Intensive, agglomerate-free and homogeneous mixing-grinding of products: that consist of two or more components.
- Trouble-free continuous operation: Products which cannot be ground in sieve mills due to their tendency to clog the sieve perforations - especially fine-mesh sieves - can be ground to high fineness values. Rinsing air protects the bearing unit from product ingress and prevents product from depositing behind the pin discs.