In coal fired power plant, coal mill and ball 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.
The coal flow into the boiler is an important factor for a coal fired power plant. But in fact, it is not easy to measure the coal flow from the coal mill to the furnace. The coal flow out of the coal mill is often estimated based on the incoming coal flow. Usually we grind coal into powder to improve the using efficiency. This way is common in Electric Power Plant. In this milling process, coal mill plays an important role.
Coal mill has many kinds, such as ball mill, raymond mill, vertical mill, ultrafine mill etc.
Ball mill is most widely used coal mill. It is suitable in the powder plant, and widely used in powder-making production line including cement, silicate, new-type building material, refractory material, fertilizer, ore dressing of ferrous metal and non-ferrous metal, glass ceramics, etc. It is divided into two rubbing way-the dry and the wet. There are two kinds of ball mill, grate type and overfall type due to different ways of discharging material. The ball mill is a key equipment to grind the crushed materials after the material were broken , and carrying on the smashing again.
Ball mill liners are mostly made of metal materials, but also a small amount of non-metallic materials. In addition to protect the cylinder liner cylinder, but also the movement of the grinding law of impact, in order to adapt to different working state (crushed or broken bits) requirements, lining the shape and material are also different. When the order to crush the main, require the lining of the grinding capacity of a strong elected body, while lining should have a good fighting performance. High manganese steel ZGMn13 have sufficient impact toughness, and dealt a blow when it is able to work hardening the surface becomes hard wear-resistant. Therefore, the main crushing mill cylinder liner are mostly high-manganese steel manufacturing.
Where the finely ground-based, the lining of the highlights on the relatively small body elected to the ground on the weak, the impact is smaller than strong abrasive. Require lining has a good wear resistance. Domestic mill mainly used for fine grinding cylinder liner materials are generally wear-resistant white iron, chilled cast iron, ductile iron and other rare-earth manganese. In recent years, widely used in rubber liner. Shape rubber lining rubber layering generally peaceful lining of two parts.
According to the working state of the different mill, rubber lining of the bead is also made to be corresponding to different shapes in order to change the tube mill grinding body in the law of motion.
Vertical Mill is a kind of large scale powder mill which is designed specially to solve the problems of low capacity and high consumption of industry mills. With a decade of years research of mills, vertical mill is designed and manufactured based on our advanced design idea, and in combination with the european technology and the market demand. LM Vertical Roller Mill adopts reliable structure and reasonable process flow, integrated with drying, milling, classifier, elevator. Especially, it can fully meets the requirement of clients in the high production of powder, and its main technical and economy indicator reachs the international level.
Raymond mill is the early coal mill, all the finished particles have a good uniformity of finess, with passing screen rate as high as 98%. This is what other machine can not reach. Ultrafine grinding mill is a equipment which produces thin powder and super thin powder. It will highten pollution and noise by using deduster and muffler, which achieves environmental protection requirement.