Lasting Durability Vertical Roller Mill Precise Classification Efficiency

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.