Thread Content
Advantages and development history of vertical mills. Vertical mills are ideal large-scale grinding equipment, widely used in industries such as cement, power, metallurgy, chemicals, and non-metallic minerals. It integrates crushing, drying, grinding, and grading/conveying into one unit, offering high production efficiency; it can grind bulk, granular, and powdered raw materials into the desired powdered form. The first vertical mill was developed in Germany in the 1920s. Some people say that its grinding principle is similar to that of the mills used by our ancestors to grind grains; it utilizes a bed-type grinding mechanism to process materials, overcoming many of the shortcomings of the ball mill grinding process. It offers advantages such as high grinding efficiency, low power consumption (20%~30% less energy usage than ball mills), strong drying capacity, the ability to handle larger particle sizes of material, a simple grinding process, small floor space requirements, low construction costs, low noise levels, reduced wear and tear, longer service life, and ease of operation. After 90 years of development, vertical mill technology has become highly mature. Especially since the 1960s, with the emergence of preheating and pre-decomposition technologies and the enlargement of new dry-process cement production lines, vertical mills have been widely used in the international cement industry, leading to further improvements and enhancements in their technical capabilities. Several foreign companies have successively developed various types of vertical mills, all with good results. The LM vertical mill is produced by Lichhe Company in Germany, the MPS vertical mill by Feifan Company, the RM vertical mill by Berle Hughes Company, the Atox vertical mill by Smith Company in Denmark, and the UB-LM vertical mill is manufactured by Ube Corporation in Japan. At present, the largest vertical mills in the world can achieve a production capacity of 600 t/h, and they can be used to grind cement raw materials for cement production lines with a clinker output of 8,000 t/d. Just a few years ago, due to changes in the industrial policies for China’s cement industry and the expansion of production capacity, the country was forced to import dozens of raw material vertical mills from abroad to support cement production lines with a capacity of 4,000–6,000 t/d. To date, our country has developed various types of vertical mills with independent intellectual property rights, which have been successfully applied in the grinding processes of raw materials, coal powder, slag, and cement in the cement industry. These include the MLS and MLK series of vertical mills produced by Shenyang Heavy Machinery Group, the HRM series manufactured by Hefei Cement Research and Design Institute, the TRM series developed by Tianjin Cement Industry Design and Research Institute, the CDRM series created by Chengdu Building Materials Industry Design and Research Institute, the ZGM series of medium-speed roller coal mills produced by Beijing Electric Power Equipment Factory, as well as the LGM and LGMS series of vertical mills made by CITIC Heavy Machinery. The application of Fushilan technology in Smith vertical mills I. Wear repair of vertical mill rollers and grinding table linings During use, if a clearance arises between the roller body and the wear-resistant lining, it will lead to increased wear between them. Coupled with the continuous erosion of the mating surface by hot air and cement particles, grooves are formed, which result in impacts between the roller body and the lining. In severe cases, this can cause cracks or even breaks in the lining, leading to machine damage – particularly damage to the reducer, which may result in serious consequences. Once such problems occur, conventional repair methods are often ineffective, and the replacement cost is high. The excellent mechanical properties and good plasticity of Fushilan materials enable this problem to be solved. II. Repair of wear in the bearing housings of vertical mill rollers: The assembly requirements for the bearings of vertical mill rollers are quite strict; companies generally use dry ice to cool the bearings during assembly. Once a gap appears between the bearing and the bearing housing, it will affect the proper operation of the bearing, causing it to overheat; in severe cases, this can lead to the bearing burning out. Fushilan technology is fast, simple to operate, and in many cases allows for on-site repairs. III. Treatment of leaks in vertical mill reducers – Leaks in vertical mill reducers not only affect the aesthetic appearance of the machine but also result in oil waste, causing significant difficulties in the maintenance of the equipment. Fushilan 25551 fast-curing material, combined with 3223 rubber repair material, allows for the repair of leaks on-site without shutting down the equipment; it is easy to use and yields excellent repair results. In addition to the above, Fushilan is also widely used in various other equipment at numerous cement manufacturing plants; it not only helps these companies save on maintenance costs but, more importantly, reduces downtime. It is a reliable partner for businesses. Note: Introduction to Danmark Smith Company. Danmark Smith Company was founded in 1882 in Copenhagen, the capital of Denmark. With a history of over a hundred years, it is the world’s oldest company specialized in manufacturing complete sets of production machinery for cement plants. It is a large multinational group company that engages in the engineering design of entire cement production lines, as well as in the research and development of new cement processes, technologies, and equipment. It provides comprehensive technical services and after-sales support to customers around the world. Today, in addition to its headquarters in Copenhagen, Smith Company has design and R&D branches in the United States and India. In addition, it has wholly-owned or joint venture cement equipment manufacturing plants in Denmark, the United States, Germany, the United Kingdom, Brazil, Mexico, Switzerland, Italy, China, and other countries. Smith Company has 24 representative offices in countries around the world. In addition to the cement industry, Smith Company’s main business activities also include FFE Mining Company. The company currently has around 6,500 employees worldwide, of whom nearly 2,000 are based at its headquarters in Copenhagen. Over the more than 100 years since its establishment, Smith Company has supplied nearly 2,000 sets of cement kiln systems of various types and models to countries around the world, as well as about 5,600 mills for grinding raw material, cement, and coal powder. Since the late 1990s, Smith Company has maintained a market share of over 50% in the global cement equipment sector, with around 70% of the imported cement equipment in China coming from this company. It is one of the largest and most advanced suppliers of complete cement equipment in the world, driving continuous innovation and development in the technology and equipment used in the modern cement industry.