Finite Element Analysis Of Large Vibration Dryer And Its Application

Vibration fluidized bed dryer is a kind of device through which the vibration energy isadded to ordinary fluidized bed in order to achieve an improvement of drying and fluidizationquality and get relatively uniform fluidized state under relatively low fluidizing drying gasvelocity. The contact between the gas and solid, solid and solid was strengthened to reduce theprobability of bonding between materials, thereby the rate of heat transfer between thematerial and hot air was increased and the production process was strengthen and the qualityof the production was improved because of the generates a pulse beat between the materialparticles. But for now，there are a lot of issues were not resolved of the vibration fluidized beddryer. First of all, the residence time of the materials of the vibration dryer currently used isshort, the drying purposes of the high moisture content material was not reached, the bodylength must be lengthened or the height of machine must be increased to extend the dryingtime of which will increase the area or space. Secondly, there is only a layer of sieve of theconventional vibration fluidized bed dryer, so that the hot air and the material only exchangeonce in the drying process, and a considerable part of the remainder heat was took away byhot air, so the thermal efficiency is low, the thermal efficiency is lower especially in the hightemperature drying. Again, the structure of the multilayer sieve vibration dryer which wasstructurally improved from the traditional vibration fluidized bed dryer is generally morecomplex, and of which the structural stability is low under vibration, the life of which is low.Accordingly, it has important theoretical significance and practical value for the developmentof Chinese drying industry to improve the structure of conventional vibration fluidized beddryer, and design of a new kind of multilayer sieve vibration dryer, so that the structure is assimple as possible, and the drying efficiency and thermal efficiency is improved, so a longerservice life is possible to be achieved.On the base of summarizing the research status of domestic and foreign vibration dryer, thedesign of a multi-storey symmetrical vibrating dryer was completed according to the givendesign requirements and design data in this paper, the modal analysis and harmonic responseanalysis was finished using the finite element software ANSYS, and then the structure of the vibration dryer was improved according to the analysis results. The works finished in thispaper are as follows:(1)The design of a multi-storey symmetrical vibrating dryer was completed according tothe given design requirements and design data. The innovation of the material moving routeof the vibration dryer was done. The3D model of the multilayer symmetric vibration dryerwas built in three-dimensional modeling software SolidWorks, then the model was importedinto HYPERMESH in meshing.(2)The meshed model of the vibration dryer was imported into finite element analysissoftware ANSYS for modal analysis to solving vibration dryer before the8-order naturalfrequencies and mode shapes. The results show that the operating frequency of the vibrationdryer can avoid the natural frequency, because the vibration dryer is working over resonanceregion, so it can effectively avoid resonance and play a very good isolation effect.(3)Then the harmonic response analysis of vibration dryer was done, the displacement andstress conditions of vibration dryer screen box under the periodic variation of the excitingforce was researched and analyzed. The results show that the overall stress distribution of thescreen box is relatively uniform, but the maximum dynamic stress is greater than theallowable stress, this stress concentration phenomenon makes vibration dryer prone to fatiguefailure at work, so the condition do not meet the design requirements.(4) The design of vibration dryer is unreasonable, so the structure modification of the partsof the screen box was done. And the modal analysis and harmonic analysis using the finiteelement software ANSYS was done. The results of modal analysis show that although thenatural frequency of the structurally improved vibration dryer sieve box changes, its operatingfrequency will still be able to avoid the inherent frequency, effectively avoid the occurrence ofresonance. The results of harmonic response analysis show that the dynamic stressdistribution of the structurally improved screen box tends to be uniform, and the maximumstress is much smaller than the allowable stress of the screen box, and the structure is able tomeet the requirements of the use of vibration dryer. In addition, the reduction of vibrationdryer overall weight forced the exciting force and the motor power decreasing, the energysaving, environmental protection and using life of the vibration dryer had greatly improved. In summary, the innovation of this paper is to improve the structure of the traditionalvibration dryer and design a multi-layer symmetric vibration dryer to increase materialmoving routes and improve the production efficiency considering the drying process; whilethe drying hot air can be repeatedly used, the efficiency of energy utilization can be improved.According to the finite element analysis of the vibration dryer screen box, the improvementsof the structure of vibration dryer was completed, making the dynamic stress distributiontends to be uniform, alternating loads of stability and longevity is improved.