Rol­ler screen

Mül­ler roller screens are used primarily for ore-screening and dedusting and for the rough classification of contaminated feed materials in primary crushers.

These materials might be:

 

  • Chalk
  • Granite
  • Basalt
  • Marl
  • Soils
  • Coal
  • Bituminous coal
  • Lignite etc.
  • Salt
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    Rollenrost Rollenrost

    MÜLLER roller screens:

    • Their constant movement separates and cleans very dirty feed materials
    • Used in primary crushers
    • Optimum cleaning thanks to the stepped arrangement of two roller screens
    • Can be made in different lengths and with different widths and gap widths
    • Roller screen axles are made of special steel in thicknesses of 100mm to 180 mm
    • Equipped with triangle plates made of highly wear resistant special steel
    • Cleaning rakes under the axles of the roller screen prevent materials from caking onto and blocking the axles
    • Axis drive via strong roller chains that run in an oil bath
    • Block bearing housings screwed to steel frame
    • Individually lubricated bearings; central lubrication on request
    • Driven by an electric standard motor + timing belt transmission + gear + flexible coupling
    • Separate console for drive unit

     

    Rollenrost Rollenrost

     

    The polygonal and round discs are mounted under tension on square shafts on the roller screen axles. The rotation of the shafts loosens and sieves the material, which is then rotated and simultaneously transported by the friction/form fit.

     

    The constant movement separates moist and loamy materials, and materials that are hard to separate and clean such as sticky clay and stones by gap width.

    The optimum dedusting effect is achieved by the stepped series connection of two roller screens, since the material rolls over once as it drops down onto the next level. It is also possible to separate two different grain sizes here.

     

    This is achieved e.g. by using an 8- and a 7-axle roller screen, with the first one sorting the fine cut (e.g. 0 – 60), and the second one the coarse cut (e.g. 0 – 120 mm).

     

    Mül­ler roller screens are made in a wide range of lengths, widths, gap widths and designs to suit the respective feed material and installation situation. Using roller screens achieves finer results in the forescreen because the roller screen cannot stick or block.

     

    This is why the operators of lots of crushed stone works and gravel crushing plants are replacing their existing pre-screens with a roller screen adapted to the length.

    The roller screen axles are made in the appropriate thickness between 100 mm and approx. 180 mm to suit the feed materials, which means that the most diverse feed sizes can be moved. Classification is between 40 and 150 mm.


    The roller screen is powered on one side by a drive shaft that transmits the power to the other side. There, the individual axles are driven by strong roller chains in an oil bath.

    The axles run in spherical roller bearings with easily accessible lubrication, but can also be lubricated centrally. Strippers are fitted under every axle to prevent the material from sticking to the shafts.

    Depending on the size of the roller screen (5 axles 1000 mm wide to 18 axles 2500 mm wide) and output (100 t/h – 2000 t/h), it is driven by standard electric motors with outputs from 15 kW to 2 x 37 kW.

    The drive force is transmitted between the motor and the gear by a V-belt drive. There is a flexible coupling between the gear and the drive shaft that reduces the alternating loads from the roller screen axles. The entire drive unit stands on a separate console that is connected to the steel construction of the roller screen.

    We will be pleased to design a roller screen just for you!

    Adjustable roller screen VR 35 AMR

     

     

    Au­gust Mül­ler GmbH & Co. KG (AMR) has developed a mechanically/hydraulically adjustable roller screen. The designation “Roller screen VR 35” indicates that the spaces between the axles can be adjusted by 35 mm.

     

    In the version that deviates from the old, tried-and-trusted AMR sys­tem synchronisation of the individual axles by chain drive, the drives are powered by individual electric gear motors. This means that, rather than being arranged in a concurrent line, the rhomboid discs are offset around the round discs.

     

    The advantage of single drive via electric gear motors is that every axle is controlled by frequency convertors and can be driven at its own speed, which reduces clogging. Another benefit is the ease of maintenance and repairs that is the result of using single drives and a coupling.

     

    Needless to say, particular attention was also paid to the dedusting of the roller screen VR 35 in its development. The strippers placed centrally under the individual axles are driven at the same ratio as the individual axles, i.e. they are concurrent with the adjustment mechanism.

    Like the standard version, the new version of the roller screen VR 35 is also made in various lengths and widths, and with different thicknesses of the square axles.

     

    The gaps of the last 4 axles of each roller screen VR 35 are adjustable. The hydraulic adjustment is effected by electronic control of the hydraulic system. A flow divider ensures that the 2 hydraulic cylinders receive just the right amount of oil at just the right pressure. This means that oil pressure keeps the double-acting cylinders at a constant setting under firm pressure. Adjustment is continuous, but only when no material is being charged.

     

    We recommend positioning a two-piece slide with reversible belt conveyors under the roller screen in order to fully utilise the adjustability of the roller screen. The newly developed roller screen VR 35 is made as a single-step machine, and can be installed in almost any primary crusher instead of a conventional screening machine or stepped bar screen.

     

    Just talk to our team of experts, who will be pleased to advise you – and to visit you to do so!