Birullo Mills - Pennati Costruzioni Meccaniche S.r.l.

The Birullo style mill (twin roller) is used to grind various types of very fine materials and minerals, such as coal, petroleum coke, talc, gypsum, oxides and phosphorites.
It crushes by compression and can achieve high throughputs (up to 15 tonnes per hour); product size is achieved by a dynamic selection system built into the mill.
Crushed product is discharged by a pneumatic conveying system.
The standard machine is provided with a filter for the separation of the aeriform phase from the solid phase (crushed product) and an exhaust fan which keeps the entire line under suction.
The PLC control automatically regulates incoming feed rates and main process parameters.
The Birullo mill is available in four different sizes based on the throughput required.
  • Features
    • Grinding rollers in Ni-hard cast iron alloy, mounted on roller bearings force-need oil lubricated.
    • Track in crom-hard cast iron alloy, divided into 4 parts.
    • Possibility of grain size adjustment by means of dynamic selector driven by frequency inverter.
    • There is no reciprocal contact between the grinding rollers and the track; there is always a certain space between them, that is held by some proper spacings; the distance can be changed in such a way as to remain the same as the consuption increases.
    • The rollers rotation is due to the friction of the material only.
    • There is the contemporary drying of the wet materials, by hot air.
    • Working is completely automatic; the feeding is driven by electronic equipment.
    • The pneumatic circuit is in suction, in order to avoid any dust.
  • Models & sizes
  • How does it work

    The raw material gets into the mill through the inlet charge in the pos. 1, and falls on the rotating track in the pos. 2, that is driven by the gear reduction unit in the pos. 3. The material insinuates under the grinding rollers in the pos. 4 (idle on the shafts integral with rocker arms in the pos. 5) and causes them to turn and grind. During grinding, the rollers rotate and swing integral with the arms in the pos. 5, having their fulcrum in the hinges of the pos. 6. The swinging is opposed by the springs in the pos. 7. Through the opening in the pos. 8, air is sucked into the mill and lifts all grinded material up to the rotating dynamic selector in the pos. 9. Coarse grinded material is re-cycled by the selector and falls down to the track, then it is further on refined, while the finest grain size is sucked pneumatically through the air intake in the pos. 10. The rotary selector speed can be adjusted by the inveter in the MCC, and it changes the RPM of the electric motor in the pos. 11.

    How does it work-Birullic Mills
  • References list of fine pulverization Plants by "Birullo" Mill
  • Grain size diagrams
  • Capacity
  • Typical installations
  • Pictures