HK coal vertical roller mill can grind all kinds of coal, which has
the advantages of longer working life, lasting durability, precise
classification efficiency, easy maintenance and operation, flexible
liner replacement.
HK coal vertical roller mill has a compact design, which can save
factory area and lower investment. HK coal vertical roller mill
crush and grinding coal into powder by the compression and shear
force from the rollers and grinding table. And the coal powder
fineness can also be guaranteed by the advanced designed turbine
classifier.
HK coal vertical roller mill can grind and dry raw coal with up to
15 percent moisture level. By adjusting the gas flow stream with
the nozzle, you can deal with more ‘sticky’, high-moisture coal.
There is an oversized nozzle ring and separator that is available
to make this adjustment.
As there is hot gas system to the coal vertical roller mill, the
moisture in the coal will evaporates at a very fast speed. And the
hot air will bring the fine coal powder to the pulse-jet collector.
For safety reasons, the coal vertical roller mill is designed with
no external recirculation of coal powder. And the coarse coal
powder that cannot go through the classifier will fall down onto
the grinding table for being reground. The coal powder fineness can
be controlled by adjusting the classifier motor speed. The
classifying efficiency is guaranteed by the advanced designed
turbine wheel and rotation speed control.
Anti-explosion system is also provided by HK coal vertical roller
mill for safe operation and running. As a safety precaution, inert
conditions can be created by using kiln exit gases and recycled
filter air.
The HK coal vertical roller mill material is also wear-resistant
and durable for longer working life. The reversal of roller cover
can also prolong the working life. And the liner is also specially
made with special material coated.
The coal vertical roller mill classifier ensures higher classifying
efficiency through specially-designed turbine wheel. And this
efficient separator also brings lower power consumption with higher
output and low vibrations. The turbine wheel blades are also made
with special steel for longer durability.
Safety device of coal vertical roller mill
Coal powder can, under certain circumstances, combust, flash ignite
or explode as a result of:
• an increased O2 content (> 12 %) in the process room
• ignition sources being present
• large quantities of volatile material being present
• an increased CO content in the process air
• the fineness of the grinding material
• the temperature of the material and process air.
In order to prevent explosion, the follow steps are taken:
• internal operating status with max. O2 contents of approx. 10 %
• pressure-shock resistant structure
• adequate pressure relief surfaces
• O2 monitoring
• CO monitoring
• plant safety design in compliance with local regulations.
Nowadays, safety and monitoring measures are equipped with coal
vertical roller mill with a help of computer monitoring system.
