LM vertical roller mill

LM vertical roller mill

Based on the absorption of advanced technologies of famous international corporations and 30 years’ experience in grinding mill production, SBM has launched the LM Vertical Grinding Mill which integrates five functions of crushing, grinding, powder selection, drying and material conveying. It is characterized by centralized technological process, small occupational area, low investment, high efficiency, energy conservation and environment protection.

Product Features: Integration of multiple functions, more stable and reliable production and more excellent capacity
  • Input Size: 0-70mm
  • Capacity: 3-340TPH
  • Material: Limestone, calcite, dolomite, petroleum coal, gypsum, barite, marble, talc, coal powder, etc.
  • Application of vertical roller mill

    LM series vertical roller mill is generally utilized in the grinding approach of metallurgy, creating supplies, chemical, mining as well as other mineral industries, and appropriate for grinding quartz, feldspar, calcite, talcum, barite, fluorite, uncommon earth, marble, ceramic, bauxite, manganese ore, iron ore, copper ore, phosphate rock, red iron oxide, zircon sand, slag, cement clinker, activated carbon, dolomite, granite, garnet, iron oxide yellow, chemical fertilizer, compound fertilizer, fly ash, bituminous coal, coking coal, lignite, magnesite sand, chrome oxide green, gold, red mud, clay, kaolin, coke, coal gangue, porcelain clay, kyanite, fluorspar, bentonite, rhyolite, pyrophyllite, shale, purple stone, Diego rock, basalt, gypsum, graphite, silicon carbide, thermal insulation elements as well as other non-flammable burst materials whose Mohs hardness are under 9.3.

    Characteristics of vertical roller mill

    Less Comprehensive Investment

    LM Vertical Grinding Mill integrates crushing, drying, grinding, separating and transport. The structure is simple while the layout is compact. Its occupational area is about 50% of that of the ball-milling system. The LM grinding mill can also be arranged outdoors, which greatly reduces the investment cost.

    Comprehensive Optimization, Lower Operating Costs

    From aspects of grinding efficiency, powder drying, abrasion of vulnerable parts and maintenance & replacement of spare parts, SBM’s LM Vertical Grinding Mill achieves lower energy consumption, stronger drying capacity, as well as lower abrasion and easier checks of core parts, saving the operating costs greatly.

    Short Grinding Time & Low Iron Content

    The materials linger in the grinding mill for a short time, which can reduce repeated grinding and is easy to detect and control the grain size and chemical component of the product. In addition, the grinding roller and millstone do not contact directly. The iron content in the product is very low, and the iron generated due to mechanical wear is easy to be removed, thus effectively guaranteeing the whiteness and purity of the material.

    Greener & More Automated

    The operation of LM grinding mill is stable and has small vibration, so that the noise is small. The system is sealed in an integral manner and works under negative pressure, so that there is no dust spilling and the environment can keep clean with the emission standard far better than the international standard. LM grinding mill is also equipped with expert-level automatic control system, which can realize free switch between remote control and local control. The operations are simple and labor-saving.

    Digitalized Processing, Higher Precision

    There are tens of lines of numerical controlling machine tools. Operations such as steel plates’ cutting, bending, planing, milling and paint spraying are all controlled numerically. The machining precision is high, especially for the core parts.

    Sufficient Supply Of Spare Parts, Worry-Free Operation

    SBM, whose businesses cover production and sales, takes responsibility for every machine produced by ourselves. We can offer customers technical services about products and original spare parts to ensure the worry-free operation.

    History of the development of vertical roller mill

    The vertical roller mill is a vertical roller mill. The first vertical roller mill was developed in Germany in the 1920s. Some people say that its grinding principle is similar to that of our ancestors for grinding grain. It uses the material bed grinding principle to grind materials, which overcomes many defects of the ball mill grinding mechanism. The vertical roller mill (vertical roller mill) produced by Shanghai SBM Machinery has high grinding efficiency, low power consumption (20% ~ 30% power saving than the ball mill), large drying capacity, allows large granularity of grinding materials, and grinding process. Simple process, small footprint, low construction cost, low noise, low wear, long life, easy operation, etc.

    After 90 years of development, vertical roller mill (vertical roller mill) technology has been very mature, especially since the 1960s, with the birth of preheating and pre-decomposition technology and the large-scale production of new dry cement production lines, vertical roller mills It has been widely used in the foreign cement industry, and its technical level has been further improved and improved. Many foreign companies have successively developed various types of vertical roller mills, and all have achieved success. At present, the largest vertical roller mill in the world has a single output of 600t / h, which can be used to match the 8000t / d clinker cement production line with ground cement raw materials.

    Just a few years ago, due to changes in the industrial policy of the cement industry in China and the expansion of production scale, China had to import dozens of raw material mills supporting foreign cement production lines ranging from 4000 to 6000 t / d from abroad. So far, China has developed an SBM vertical roller mill (vertical roller mill) with independent intellectual property rights that has been successfully used in the grinding of raw meal, coal powder, slag and cement in the cement industry.

    Reasons for reduced powder discharge in vertical roller mills

    It is time for the vertical roller mill to grind powder. What should I do if I find that the amount of powder discharged has decreased? This is a very tricky thing for the staff. Do n’t panic if you encounter such a problem. Also, do not immediately shut down the equipment. If other equipment is operating normally, the main reason for the reduction in the output of the finished product of the vertical roller mill is probably the blocking of powder. Powder blocking in vertical roller mills is a relatively common mechanical failure. Powder blocking can occur due to material reasons, equipment failure reasons, worker operating reasons, etc. So how to avoid the phenomenon of powder blocking in the vertical roller mill? Once the powder is blocked, how to deal with it? In order to avoid the powder blocking in the vertical roller mill, we must understand its causes. We mainly analyze the vertical roller mill. An important reason for plugging:

    • 1. Wet material

    As a common factor, the ground material is too humid, and the fine powder is easily adsorbed on the powder discharge port, which causes the air duct to be blocked and affects the powder discharge. In this case, it is necessary to remove the powder blocking plug in time to see if the material is wet and it is necessary to dry it.

    • 2.Feeding speed is too fast

    The feed speed of the vertical roller mill must be stable, and the feed amount cannot be suddenly increased because it wants to increase the output. This will easily cause material accumulation and blockage of powder.

    • 3. Second, the discharge port of the cyclone collector is under negative pressure and the discharge is relatively tight.

    If the discharge valve leaks air during work, the separated materials will be re-rolled into the cyclone collector. When the core air enters the air duct, this will not only cause blockage, but also reduce production.

    • 4.Fan failure

    The long-term operation of the fan is prone to failure, which reduces the amount of air and affects the powder discharge. At the same time, the failure of the bag filter to easily cause the circulation air in the vertical roller mill to weaken, which causes dust to accumulate in the air duct and reduce the amount of powder discharged.


Working Principle

The grinding plate rotates under the action of main motor of LM vertical roller mill and the reducer. Meanwhile, hot wind enters the vertical mill. After raw materials fall onto the center of grinding plate, they move to the edge of grinding plate under the action of centrifugal force. While passing through the grinding area between roller and grinding plate, bulky materials are broken directly by the pressure of roller while fine materials form a layer where materials crush each other. Broken materials after grinding continue moving to the edge of grinding plate until they are brought away by the airflow at the air ring. For coarse materials which cannot be brought away would fall onto the grinding plate for another grinding. When passing the upper separator, materials in the air flow will be divided into two parts by the blades of rotor, that is, coarse particles and fine powders. Coarse particles would be sent back to have another grinding while the qualified fine powders enter the powder collector with airflow as finished products. For sundries like iron block in materials, when they move to the fringe of grinding plate, because of their heavier weight, they would drop to the lower cavity of grinding mill and next be sent into the discharging port by scarper installed at the bottom of grinding plate and finally be discharged out of the grinding mill.

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