Vertical Roller Mill Vertical Roller Mill Technology
1. Cost Savings The single largest energy consumption point in the manufacture of portland cement is in the finish milling process. A reduction in power consumption here makes a dramatic impact on the plant's overall power consumption. VRM technology makes significant power reductions possible by more efficient grinding.
2. Quality Vertical Roller Mill create a particle size distribution with a sharper cut in comparison to cement milled in a traditional ball mill. That is, the particle size distribution is in a narrower band. This sharper cut means potentially less variability in product consistency and, hence, more predictable results in product performance.
3. Process Simplification By changing various Vertical Roller Mill operating parameters, significant adjustments in the particle size distribution, retention time, and fineness of the finished cement can be achieved. This can help with plant operations as production is switched between different cement types. In light of these issues, vertical roller mills are becoming a popular choice for both existing ball mill conversion and new mill construction. From 2000-2002, 56% of the mill orders (comprising both raw mills and finish mills) came from vertical mills compared to 32% for ball mills. Clearly vertical roller mills are an increasingly attractive option for improving production, lowering energy costs, and maintaining product quality.
Vertical Roller Mill Structure and function :
The main structure consists of separator ,roller, mill table, pressurization device, deceleration machine, motor, shell body, etc. Separator is an important part which determines the size of the final powder.It is composed of gearing with adjustable speed , rotor, guiding vane, shell body , cone filler for coarse powder, blower. It is a kind of powder collector with high-efficiency , low powder consumption and convenience. Roller is the main part to grins the materials into powder. Vertical Roller Mill is equipped in the curving arm of the mill. In virtue of the outside force, It pressed the materials on the table tightly. Driven by the mill table ,the roller runs, so the materials are grinded into pieces. The mill table is fixed at the output shaft of the deceleration machine. At the upside of the table is the hoper with an annular groove in which the materials are grinded. The pressurization device brings the grinding pressure. It contains oil pressure station, pull rod of hydraulic pressure for grinding. Deceleration machine carries powder.
The rotate speed of the mill table is the machine's output speed. According to the position of humidifier and dust collector. Our company can provide 2 allocation :three blower system and double blower system. This vertical grinder collect the finished products by whirlmind dust catcher. This configuration can reduce the working negative pressure and the volume of gas which through the dust catcher. In vertical grinder can use electrical dust catcher ,also bag dust catcher as terminal dust removal plant. By using the electrical dust catcher and bag dust catcher ,the gas can directly go from grinding into dust catcher. This construction can reduce the quantity of equipments and also simplify the allocation. Vertical Roller Mill Working principles : The motor dives the grinding table to turn through the speed reducer. At the same time, hot air comes into the roller mill from the air inlet. The materials fall down the centre of grinding table from the feeder. Because of the centrifugal force, the materials move to the edge of grinding table from the centre .The materials are crushed by the grinding roller when by pass of the groove on the grinding table.
The crusher materials continue to move to the edge of the grinding table until taken away by the airstream. Then the bigger materials fall down the grinding table and the process of crushing continues. When the materials in the airstream pass the separator on the top of the mill, the materials fall down the grinding table from the taper filler under the force of guide leaf blade. The fine powder comes out with the airstream, and is gathered by the dust catcher of the system. The powder gathered is the final product of roller mill. In the process of the contact of airstream , the materials are dried to meet the clients' need at the proper moisture.Through the adjustment of the angle between the separator and the leaf of wind's direction (not suitable to the small type of vertical mill), and also the speed of the separator rotor, it can reach the proper fineness of the materials.