| Compared with ordinary belt conveyors,air cushion belt conveyors replace idlers with air cushions to support conveyor belts,convey materials,which has the advantages of energy saving,environmental protection,high efficiency and low friction,and is more and more widely used in the bulk material conveying industry.With the improvement of the industry’s performance requirements for conveying speed,conveying volume and conveying distance,the defects of traditional air cushion belt conveyors have gradually emerged,such as the phenomenon of "crushing","streamers" and "edges".In order to adapt to the development trend of high-speed,heavy-duty and long-distance transportation,this paper takes the standard section of the key component of the air cushion belt conveyor as the research object,designs its structure,improves its design theory,analyzes the bearing mechanism and dynamic characteristics of the air cushion flow field,discusses the bearing characteristics and operation stability of the air cushion belt conveyor under the action of fluid-structure interaction,and provides a theoretical basis and reference for the design and application of air cushion belt conveyor.Firstly,on the basis of in-depth study of the design theory of air cushion belt conveyor,this paper combines the engineering practice,according to the requirements of high-speed and heavy-duty transportation conditions,determines the overall layout scheme of air cushion belt conveyor,designs the key component of air cushion belt conveyor-standard section,mainly compares and selects the air chamber structure,disc groove shape and porous layout contained in the standard section,and designs and calculates the conveying volume and gas supply device and other parameters.Secondly,based on the relevant theories and basic equations of fluid mechanics,the gas flow field characteristics of the standard section of the air cushion belt conveyor are theoretically analyzed,and the theoretical distribution model of air cushion pressure,the flow model near the pores,and the lateral outflow model of the air flow are established.The theoretical distribution curve of air cushion pressure under the design scheme is obtained by numerical analysis software,and the velocity and pressure distribution function expressions of the flow model near the stomata and the lateral outflow model of the airflow are derived.Then,the three-dimensional model of air cushion belt conveyor with different air chamber and disc groove structures was established by using SolidWorks,and the dynamic characteristics of the flow field were simulated and analyzed based on the computational fluid dynamics software Fluent.The influence of different air chamber structure and different stomatal layout on the pressure and distribution of air cushion was simulated,and the disc groove structure with crescent arc air chamber and seven rows of holes staggered was determined,and the comparative analysis showed that the bearing capacity of the air cushion of the designed standard section structure met the design requirements and had small pressure fluctuations.Finally,based on the basic theory and control equation of fluid-structure interaction,considering the coupling relationship between the air cushion and the conveyor belt,and through the two-way fluid-structure interaction,the deformation of the conveyor belt under heavy load and the change of the flow field performance of the air cushion are simulated and analyzed,and the stress and deformation of the conveyor belt under the action of air cushion pressure and material gravity,as well as the influence of conveyor belt deformation on the pressure distribution of the air cushion.The simulation results show that the conveyor belt meets the design requirements,and the air cushion area has sufficient load carrying capacity and stability under the action of fluid-structure interaction. |
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