Raw Mill airlock feeders are popularly used for feeding limestone lumps to raw mills and coal mill in cement industry to avoid false air entering in to the mill thereby decreasing its efficiency. It is so designed to pass hot steam through the rotor pockets to reduce moisture in the material, thereby avoiding clogging of material in the rotor pockets, resulting in the reduction of capacity. These Raw/Coal mill Feeders are easy to operate and are maintainable at much lower cost as compared to the Triple gate valves which are also employed for this application.
Working Principle Of Vertical Raw Mill
The vertical raw material mill in the cement plant starts to run, the material enters the mill through the feed port on the upper side of the mill, and then falls in the center of the millstone.
- The transmission drives the millstone to rotate, and the grinding roller self-transmits around the grinding roller shaft under the friction of the millstone. Due to the centrifugal force, the material moves from the center of the millstone to the edge, and when it passes through the grinding roller track, it is brought between the grinding roller and the millstone to be crushed.
- The vertical raw mill in cement industry is equipped with a hydraulic tension device, which mainly controls the relative pressure of grinding roller to the millstone. The crushing pressure can be adjusted according to the hardness of the grinding material.
- The materials after grinding continue to move towards the edge of the millstone. There is a jet device at the edge of the millstone, and the hot air flowing outflows from bottom to top, which drives the material after grinding to rise.
- The big pieces of material will fall back to the millstone first due to its own weight, and the smaller ones will enter the powder selected system under the action of the hot airflow. The fine powder that meets the fineness requirement is collected and stored in the dust collector, while the coarse powder that does not meet the fineness requirement is returned to the millstone for grinding.