The Optimal Classification with RHEWUM Screening Machines
RHEWUM high performance screening machines type WA are used for classification of bulk material in the finest to medium grain size range. This screen type is a throw sieve which employs direct excitation of screen mesh; thus the screen housing only takes a statical function. It also preserves the building and/or the steel structure. No dynamic loads are transmitted as they are created by completely vibrating convential screens and rigid connection to on-and off-going chutework is possible.
Vibration is imparted into the screen cloth by high speed movement of a transversally mounted rocker shaft, located beneath the screen cloth. Therefore the velocity down the screen is determined by the angle of the screen deck. Outside the screen housing rugged electromagnetic drives rock the knocker shafts, conveying the high frequent oscillation directly into the screen mesh. The electromagnetic drives create high accelerations on the screening net which are up to 15 g and more. These high accelerations guarantee also a correct screening of adhesive products. The electronic control of the vibrating heads allows infinite control of the vibrator oscillation during operation and therefore a perfect adaption of vibration amplitude to product changement. Each screen deck is individually controlled and divided into inlet and outlet sections.
The high frequency vibration of the screen net effects to overcome the adhesive particle forces within the product, to loosen the product bed and to segregate the product mixture by throwing big particles above the finer ones and separating them by comparison with the mesh appertures. The machines attain unequal high specific screening capacities on the smallest possible space.
The combination of longitudinal tensioning of screen nets and free access affords easy and quick exchange of screen cloths. Maintenance of the outside the screening space arranged drives can be done during operation and due to the number of drives a possible failure of a drive does not necessitate to shut down the plant.
Standard machine sizes are in the range of 1,4 m² to 26,4 m² per screening deck resp. machine. Additional sizes and special constructions are possible on demand. Relating to these dimensions electrical power range is in between 0,52 kW to 3,9 kW(!)