| The round tube belt conveyor is a mechanism that uses a hexagonal roller set to force the conveyor belt into a round tube to carry out bulk material transportation,and has the characteristics of environmental protection,high efficiency,and flexible transportation.Among them,the inclination angle of the pipeline is an important design parameter in the design process of the round tube belt conveyor.If the expansion is serious,the serious accident of the expansion tube will occur.If it is too small,the pipeline layout of the whole machine will be too long,and the number of rollers will increase sharply.At present,the empirical method is still used to conservatively design the inclination angle of the pipeline,resulting in excessive construction cost.The paper takes the limit conveying inclination angle of the straight tube climbing section of the round tube belt conveyor as the research object,and changes the filling rate of the material in the tube belt,the spacing of the roller group and the belt speed to the ultimate conveying inclination of the round tube belt conveyor.To carry out the research,the main research method is the combination of theoretical derivation and discrete element simulation analysis,and the influence law of the three parameters on the ultimate conveying inclination of the round tube belt conveyor is obtained,and the internal relationship of this parameter is obtained.The research work of the thesis has certain reference significance for the design and determination of the inclined angle of the straight-line climbing section of the circular tube belt conveyor in engineering practice.The main research work of the thesis is as follows:(1)Due to the particularity of the physical properties of the bulk material,the physical properties of the bulk material are taken as the point of entry,and the stress state of the bulk material is analyzed,and then combined with the theory of bulk mechanics The bulk material is subjected to force analysis,and the force condition and force form of the bulk material in the tube band are obtained.Then,the relative friction coefficient is derived by the relative slip theory,and finally the theoretical derivation is obtained.The relationship between the filling rate,the guiding friction coefficient and the conveying inclination angle is obtained by the analysis: the filling rate is increased,and the guiding friction coefficient is increased,so that the conveying inclination angle is increased.(2)Using bulk coal as the simulated material,the discrete function simulation analysis shows the fitting function relationship between the friction coefficient and the ultimate conveying inclination of the round tube belt conveyor under different filling rates.The relative friction state between the material and the tube band is characterized by the friction coefficient.The combination of theoretical derivation and discrete element simulation analysis is used to obtain the linear climbing section of the round tube belt conveyor under different filling rates.The maximum conveying inclination to ensure that the material does not slip.(3)Establish the parabola equation of the circular tube conveyor belt,taking the drape of the tube conveyor belt between the roller groups as the breakthrough point and the connection point.Firstly,starting from the theoretical calculation of the drape,the influence of the drape on the ultimate conveying inclination is obtained.That is,the smaller the drape,the larger the ultimate conveying inclination angle;then the influence of the idler spacing on the drape is studied,and finally the influence of the idler group spacing on the actual limit conveying inclination is obtained;that is,the spacing of the idler group is appropriately reduced.The drape can be reduced,so that the purpose of increasing the actual limit of the conveying inclination can be achieved.The actual limit delivery angle obtained by simulation is smaller than the theoretical calculation because the belt speed also affects the ultimate delivery inclination.(4)Establish the cosine function equation of the round pipe conveyor belt,extract the single particle for force analysis,and obtain the function of the maximum belt speed to ensure that the particle does not slip in the pipe band as a function of the ultimate conveying inclination angle,and then at different belt speeds.The discrete element simulation analysis is carried out,and finally,as the belt speed increases,the stability of the material in the tube band is reduced,so that the ultimate conveying inclination angle of the round tube belt conveyor is reduced.(5)There are many factors affecting the ultimate conveying inclination of the round belt conveyor.There are some internal correlations between the filling rate of the material in the belt,the spacing of the roller group and the belt speed.Firstly,the filling rate of the material in the tube band is ensured,and the maximum conveying inclination angle of the material does not fall in the tube band is ensured.Then,based on the angle,the actual limit conveying inclination angle at different roller group spacing is obtained,and the belt speed is changed at the same time.The size will also have an effect on the ultimate delivery angle. |
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