Brief introduction of Coal mill
What is a coal mill? You are likely to answer the question immediately: it is a kind machine used to mill the coal into pulverized coal. Undoubtedly, you are right. Do you want to know more about it? Here we go. Coal mill is widely used in many factories and industries. For instance, coal powder equipments in steel mill, heat-engine plant and cement plant. It also has a promising prospect in cement mill clinker. Then when it goes to such areas as classification, maintenance that we are not familiar with, we find it necessary to know more about it.
Main Features of Coal mill
1. Compact design, Simple structure, easy maintenance.
2. Grinds any type of coal and High crushing ratio.
3. Adaptable to specific process requirements .
4. High drying ability, reliable operation.
5. Long service life of grinding parts .
6. Reliable performance, low operation cost .
7. Stable quality, convenient maintenance.
Coal mill Advantages
1. High Drying Ability
2. Simple and reliable operation
3. the stability of product quality
4. Maintenance convenience
5. Environmental protection
Working principle of Coal mill
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.
Application of Coal mill
Coal mill used at coal fired power plant
In coal fired power plant, coal mill is used to grind, pulverize and dry coal before the coal is transmitted the boiler. The coal is feed into the coal mill via a inlet pipe so that the roller coal mill such as Raymond mill and vertical mill can pulverize the coal into particles.
The hot air in the coal mill will lift the coal particles out of the Raymond mill or vertical mill and into the boiler, if the coal particles are too heavy they will drop to the bottom of the coal mill too and will be grind, pulverize again.
Coal mill for producing slack coal
According to the market research, vertical coal mill is used most widely. There are also other grinding mils like traditional Raymond mill, roller mill, trapezium mill, etc. can also meet different requirements for grinding coal into different sizes and types. Customers can choose an appropriate coal mill according to their specific needs and the output.