Medium-speed coal mill refers to a coal mill with a working speed of 50-300r/min. It is professional equipment for the preparation and processing of auxiliary materials for blast furnace ironmaking. The medium-speed coal mill can provide suitable auxiliary materials for the blast furnace ironmaking system powder. The medium-speed coal mill is the most important large-scale equipment in the coal-to-oil pulverizing system. Its operating safety and economy are very important for the normal operation of coal-to-oil. Generally, the outlet temperature of the medium-speed coal mill is controlled at 100-120 degrees Celsius.
The materials processed by the medium-speed mill cylinder are particles of various sizes and hardnesses. These materials move inside the medium-speed mill, constantly causing friction, scouring, and impact on various parts of the medium-speed mill body, and body wear is inevitable. The reasons for the wear of the medium-speed mill cylinder are relatively complicated. There are both abrasive wear caused by the sliding of coarse-grained materials, wind erosion wear caused by high-speed scouring of high-concentration dust-containing gases, and impact wear caused by high-speed impact of coarse-grained materials and even foreign objects such as grinding bodies crushed by the mill.
The wear-resistant ceramic sheet of the coal mill cylinder is used to protect the cylinder from direct impact and friction between the grinding body and the material. At the same time, different forms of linings can also be used to adjust the movement state of the grinding body to enhance the grinding effect of the grinding body on the material, which helps to improve the grinding efficiency of the mill, increase production, and reduce metal consumption.
Conventional coal mill linings include wear-resistant ceramic patches and wear-resistant ceramic liners. Especially in the area within 2 meters above the grinding disc, not only is there severe scouring, but there are also large pieces of granular materials hitting it. The traditional anti-wear treatment cannot achieve good results. The area within 2 meters above the grinding disc can be lined with a cemented wear-resistant ceramic lining. This product is made of a unique process and has the characteristics of high hardness and high toughness. At the same time, it changes the traditional pasting installation method and uses adhesive and screws for dual fixing. It is particularly suitable for use in parts with high temperatures and certain impacts.
There are two optional assembly methods for wear-resistant ceramic sheets for the mill cylinder: one is on-site installation, which requires the cylinder to be relatively flat and not uneven; the other is to install the ceramic on a curved steel plate in the factory and then weld it to the cylinder wall. At the bottom of the medium-speed mill cylinder, the impact of coarse particles splashed out by the grinding roller and the scouring of high-temperature and high-concentration powders closest to the static ring are very serious. For the area within 500mm-1500mm of the bottom of the mill cylinder, where the material particles are large, the temperature is high, the wind speed is fast, the wear is large, and the impact is large, composite wear-resistant ceramic lining plates are used. Fix the ceramic to the curved steel plate, the ceramic spacing is zero, the inner wall is smooth, and the service life is extended by about 10 times.
