Coal mining equipment
Coal mining equipment includes coal mill and coal crusher equipment in coal mining industry. jaw crusher is usually taken as primary coal crusher equipment in coal crushing plants, after crushed process, coal mill such as ball mill , Raymond mill , vertical mill , trapezium grinding mill is used for grinding process.
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.
Coal crushing machine
Coal crushing machine is used to crush coal into small size. In coal mining industry, the usually used crushing machines are jaw crusher, impact crusher , cone crusher , hammer crusher and mobile coal crusher. These coal crushers have special benfits. Large jaw crusher can crush coal with the capscity 1000 tons per hour. Mobile coal crusher is the most portable crushing plant . Sometimes, in underground mining, coal crusher is also used to crush big coal into smaller then transport them by belt conveyor . Coal washing machine is the important mining equipment. It can remove the dust, inclusion form coal.
Jaw coal crusher is the most common crushing machine. Usually it is used as primary crushing machine with high crushing ratio. Using two jaw plates to extrude the raw coals to small pieces.
Impact crusher is also the common crushing machine for coal. It is used after jaw crusher for secondary crushing. Impact plate with high chrome is wearable. The coals after crushed is cubic in shape.
Cone crusher is fine crushing machine in this process. It has four types: spring cone crusher, CS cone crusher, hydraulic cone crusher, hcs90 cone crusher. Spring cone crusher is the early cone crusher, CS cone crusher is the most common cone crusher now. Hydraulic cone crusher is adjusted by hydraulic device and lubricated by the dilute oil. And with locking sleeve assembly, it can overcome the trouble of oil and water being mixed together.
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