Research On Numerical Analysis Of Large Scale Vertical Roller Mill Characteristics And Its Application

Vertical Roller Mill(VRM) is a kind of integrated drying equipment with functions of crushing, drying, grinding, classifying, grinding and transportation which have advantages of low energy consumption, high efficiency of grinding, high grinding efficiency, small footprint, light weight, strong drying capability, long life and large size of into mill and etc.. It is widely used in the raw material preparation system in cement industry. The core part of VRM is grinding system.VRM grinding system consists of mill, roller and pressing devices and other components, to achieve functions of material extrusion, grinding, cutting and others, its dynamics, statics and flow field performance affect the VRM working conditions and production efficiency. In this thesis, large scale VRM numerical analysis methods is deeply studied, and one certain type of VRM is taken to be example to carry out practical application. The major research of this thesis is as follows:(1) The structure of large scale VRM and working process of grinding system are analyzed; Based on Pro/E, Hyper Mesh, ANSYS and ADAMS, the VRM virtual prototype data exchange methods is proposed, the seamless connect among VRM CAD modeling, dynamic simulation and finite element analysis(FEA) is achieved; The three dimensional(3D) modeling of large-scale VRM mill, roller, pressing devices and other key components are established by the application of Pro/E.(2) The multi-body dynamics system analysis is studied; Based on multi-body system dynamics, dynamics basic theory and ADAMS simulation platform, the dynamics performance analysis method of VRM is researched, the large-scale VRM dynamics mode is established; Based on simulation analysis, the dangerous working conditions and its parameters for VRM are obtained.(3) The technology of FEA is studied, the statics mechanical properties analysis method of VRM and its key components model simplification method are proposed; Based on ANSYS FEA platform, the statics mechanical properties of pressing device and mill are analyzed. According to stress and strain nephogram, the reliability of the VRM is estimated.(4) The technology of fluid dynamics analysis is studied, based on the FLUENT computational fluid dynamics analysis platform, the fluid geometric model of VRM system is established, based on the hybrid grid method, the computing grid of VRM system is created, boundary conditions are analyzed and calculated. Based onκ-εtwo-equation model, discrete phase model and the form of gas-solid coupling calculation, VRM system flow characteristics are analyzed. Based on the velocity cloud, temperature cloud, pressure cloud, flow streamline cloud and material particle trajectories cloud, powder grinding and classifying efficiency is improved.Based on the above work, one certain type of large scale VRM is taken to be example, its dynamics, statics and flow characteristics are analyzed. Optimal design method and recommendations are proposed, and the correctness and suitability of product design are verified.