ATOX® Coal Mill

An extremely compact, air-swept vertical roller mill, the ATOX® coal mill grinds and dries all types of coal and is highly economical in terms of specific energy consumption

ATOX coal mill
  • The basics
  • Maintenance

Key benefits

  • Reliable operation/high availability
  • Handles all types of coal
  • Low specific energy consumption
  • Minimal space requirements

How it works

The raw coal enters the mill via a feed screw and is discharged onto the rotating grinding table. The rotation of the table accelerates the flow of material towards the grinding track, where the coal is ground between the table and the three rollers.

The coal then continues over the dam ring and is entrained in the hot drying air that enters the mill house through the nozzle ring.

The air lifts the coarser particles back onto the grinding table and sweeps the finer particles up into the separator. When the final product leaves the mill with the air, it goes to a cyclone or bag filter, where it is collected.

Design advantages

  • Highly efficient RAKM dynamic separator ensures high-grade end product with excellent burning efficiency
  • Segmented roller and table wear parts prolong service life and make installation easier
  • Large rollers permit coarse feed and ensure a thick grinding bed for maximum uptime
  • Separator and nozzle ring are sized independently of the mill itself and selected according to the amount of gas needed for drying and conveying material
  • Reversible roller segments ensure high material utilisation, even in the case of uneven wear
  • Suitable for various installation types – inert/non-inert, direct/indirect firing systems

Plan ahead

Systematic and planned mill maintenance is important for vertical mills, where measurements and visual observations should be conducted during stable operation. Use your stoppage inspection to conduct trial tests, measurements of the roller and a table wear profile.

Rollers, grinding table

Wear on rollers and the grinding table is your biggest maintenance challenge. It is important to regularly measure the roller and table wear profile, since worn rollers or table segments result in production loss and increased power consumption.

Roller bearings

With the sealing air and roller lubrication system the roller bearings in the grinding rollers are protected best possible. Proper replacement of filter cloth for sealing air fan and replacement of oil filter elements when needed will result in long and trouble free operation It is especially important to keep coal mills up and running. Fortunately, the ATOX® coal mill is extremely simple both to operate and maintain.
Mill maintenance
Mill maintenance