Powders Choose Performance Analysis Of The Vertical Roller Mill And The Flow Field Simulation Research Based On The Multiphase Technology

Cement industry is a typical industry which dependent on resources and energy. Withthe high-speed economic development today, how to improve the quality of the product,reduce the cost of the cement production, how to hold advantage in the fierce marketcompetition has become a severe situation which the cement enterprise must confront with.As is known to all, the ball mill is the traditional grinding process, but the energy utilizationrate is low. After the vertical roller mill was used for the raw material grinding in the cementindustry, due to its remarkable energy saving effect, aroused people’s attention and interest,The vertical roller mill has unique energy principle grinding materials, which overcome somedefects of the grinding mechanism the ball mill, it is so multifunctional that it concentrationcrushing, grinding, drying, powders choose and pneumatic conveying and so on.The vertical roller mill powders choose has effect on grinding to a certain size finepowders separate，thick powders are return to the millstone for grinding again, prevent finepowders in grinding adhesion in grinding medium cause buffer action and fineness degree ofinequality. The powders choose performances of the vertical roller mill has a direct influenceon the vertical roller mill powder grinding efficiency increase or not, so research about thevertical roller mill powders choose flow field is important meaning to improve the verticalroller mill powder grinding efficiency. Evaluation index of powders choose performance ofthe vertical roller mill including: boost output of the system; reduce the system’s energyconsumption; easy to control the product reasonable fineness etc. Influence factors of thevertical roller mill performance mainly are the pressure difference, air volume, wind speed,structure of the vent ring, angle of the guide vanes etc. Factors of influence performance thevertical roller mill powders choose mainly are the pressure difference, air volume, wind speed,etc. The size of the wind speed is decided by the material particles with a height, and the sizeof the air into the vertical roller mill can be carried to the amount of material. Wind speed andair into the vertical roller mill are important factors effect the product quality of the verticalroller mill. Different pressure is refers to the vertical roller mill the import and export ofpressure loss, is one of the key parameters of the vertical roller mill operator. The stability ofthe differential pressure is very important to the normal work of the vertical roller mill. According to particle grading principle, we know that through the adjustment of the windblade angle can be changed at the beginning of the dust grain speed powders choose area ofthe eddy current streamline curvature, it can the wind leaf through to adjust the fine degree offinished products. Through to the vertical roller mill powders choose flow field of thenumerical simulation,we know when the wind leaf tilt is decorated the flow speed isincreased obviously than wind leaf radial layout, and material dispersion get better, so thewind leaf tilt is decorated to improve efficiency of powders choose.Paper use SOLIDWORKS and FLUENT for the platform, adopt Multiphase flow modeland the RSM turbulence model, analysis the trend of pressure and speed in the vertical rollermill powders choose flow field. The numerical simulation of flow field results show that, thelargest velocity in the vent ring, next is the velocity of the grinding surface of rotating,velocity in central region is minimum, fluid flow change rule of the vertical roller mill. Thevertical roller mill powders choose flow field fluid change trend accord with the flowcharacteristics of wall and core area. The dynamic pressure change trend of flow field isbottom-up increase，inside out increase，center is low pressure area, local appear high pressurearea. The dynamic pressure in the vent ring is the highest pressure，the dynamic pressure ofgrinding rotating wall is the higher pressure.The change trend of flow field dynamic pressure is decreased by bottom-up andincreased from inside to out, pressure in area between the vertical roller mill and shell isbiggest. Local existing low voltage area, for example, the area between grinding roller and thehopper is low-pressure area. Contrast numerical simulation results of the powders chooseflow field in the vertical roller mill, we can know something that along with increase of airinto, the pressure and speed of the powders choose flow field of the vertical roller millincreased obviously.