Stress Analysis And Study On Pneumatic Conveying Characteristics Of Sepiolite Powder Particle In Horizontal Tube

The horizontal circular tube is the key structural component of the sepiolite powder jet purification and classification device.The particle suspension pneumatic conveying characteristics in the pipeline is one of the main factors,which affect the particle size classification of the airflow classification device.In order to study the transport characteristics of sepiolite powder particles in horizontal pipelines,the force of sepiolite powder particles in horizontal tubes was analyzed,which based on the physical and mechanical properties of sepiolite powder particles.The numerical simulation and experimental study on the pneumatic conveying characteristics of sepiolite powder particles was researched under the different structural and process parameters.This dissertation mainly discusses the following aspects:(1)Characteristics measurement of sepiolite powder particles.The parameters of sepiolite particle on the angle of repose,collapse angle,difference angle,dispersion,density,particle size,viscosity and friction angle were measured by powder comprehensive performance tester,super depth microscope,Stormer viscometer and strain-control direct shear instrument,to provide data support for subsequent theoretical analysis and simulation.(2)Force analysis of sepiolite powder particles.Firstly,the kinetic equations of the particle phase and the gas phase are established,the force type of the particle is analyzed,and the interaction force between the particle and the wall surface is determined.Secondly,the force of the particle in the numerical simulation is analyzed by order of magnitude.Finally,the shear stress model of the particles in laminar flow and turbulent flow states is established by the force considered.(3)Numerical simulation of the pneumatic conveying characteristics of sepiolite powder particles in horizontal tubes.Aiming at the difficulty in analyzing the flow characteristics of sepiolite powder particles in horizontal tubes,a simulation analysis method for aerodynamic transport performance of sepiolite powder based on particle size and force condition was proposed.The numerical simulation of the pneumatic conveying of sepiolite powder particles was analyzed by changing the diameter and inlet speed of horizontal tubes and the particle size with COMSOL multiphysics software.(4)Experiment on pneumatic conveying of sepiolite powder particles in a horizontal tube.The pneumatic conveying experiment of different diameters,inlet speeds and particle sizes of sepiolite powder particles was carried out by constructing a horizontal pipe internal pneumatic conveying experimental platform.The particle velocity distribution and particle trajectory distribution in the horizontal circular tube were obtained,and compared with the simulation results.Theoretical analysis,numerical simulation and experimental results show that the force and simulation analysis of the characteristics of sepiolite powder particles in the horizontal tube can provide a basis for the particle size selection of pneumatic conveying under different process parameters.The purification and classification of stone powder fines and the smooth suspension of non-metallic mineral materials are of great significance,which can effectively increase the added value and utilization range of sepiolite powder with abundant reserves in Xiangtan Hunan province.