Coal Mining Equipment Introduce

Coal mill also called coal pulverzier or coal powder mill is grinding
mill that is used in coal mining industry, such as vertical coal mill.
And in general, vertical mill includes mineral series and coal series.
The first series grinder can be widely used in cement making, power,
metallurgy, chemical, ore industries. And the vertical coal mill also
called coal grinder is the most used machine for coal grinding according
to our mining experience. In some cases, coal mill is not just one
grinder mill, it will include some optional equipment such as vibrating
feeder, vibrating screen, belt conveyors and so on to finish the coal
milling process. So, coal mill is also used widely in many industries
besides coal mining.
Coal mill classification

Coal mill is an efficient tool for grinding coals into fine powder in
coal mining industry. According to its fineness and working principles,
we divide coal mill into coarse power coal mill and fine coal mill.
Coarse powder mill is a kind of new high-tech milling machine to meet
the requirements of coarse powder processing customers. It is the ideal
equipment to replace Raymond mill, ball mill, and other traditional mill
which only process fine coal powder materials.
Coal mill working principle

Raw coal is fed through a central coal inlet at the top of the
pulverizer and falls by gravity to the rotating grinding table, mixing
with classifier rejects returned for re-grinding. Centrifugal action
forces the coal outward to the grinding ring where it is pulverized
between the ring and three grinding rollers. Grinding load, transmitted
from the tension rods through the loading frame to the roller
assemblies, holds the rollers in contact with the grinding ring. The
rollers adjust vertically as the depth of the coal load increases or
decreases.

A nozzle ring on the outside perimeter of the grinding ring feeds
primary air to the pulverizer. Pyrites and tramp metal fall through the
nozzle ring openings to be scraped into a rejects hopper.

A stream of low-velocity air carries the particles of pulverized coal
upward where they enter the classifier inlet vanes. Fine particles
travel to the burners in the primary air stream, but the larger, heavier
particles are returned to the grinding zone for further pulverization.