Numerical Simulation Of Temperature Field And Fluid Field Within Vibrated Fluid Dryers

Vibration fluid bed is a kind of modification dryer equipment, in which the mechanical vibration is applied on the ordinary fluid bed. The ideal plug flow of materials as such hard to form uniform flow in ordinary fluid bed can be obtained by adjusting the vibration parameters. The drying method mainly focuses on convection heat transfer, which takes place between the hot air and materials under the uniform fluid condition. This paper deals with the working principle of vibrated fluid bed, and analysises the laws of vibration, meanwhile designs the drying process of potassium chloride salt. Finally, the fluid situation and flow features of gas-solid phase as well as temperature distribution can be simulated based on the calculation of software FLUENT and numerical result can verify the rationality of the design calculations.The simplified three-dimensional model can be established based on the processing software-Gambit, meanwhile the model can be meshed and the boundary condition can be set. This thesis analysises and calculates the fluid parameters by using O. M. Tojes relationship formula and then calibrates the result according to graphic method. The settling velocity can be determined based on the interval judgment method and also can be verified by Malinnosiki correction formula. The necessary parameters of simulation can be obtained after the design calculation.Relative precise simulation result can be obtained as for gas-solid phase when the laminar model and Euler model are loaded on calculation model, and meanwhile the energy equation is set to describe temperature distribution. Considering that there is no specified model to interpret temperature problem, so the extra model such as evaporation model, mixture model and species transport model should be added. As for two important features of vibrated fluid bed-orifice characteristics and vibration characteristics, this paper suggests that using porous media to simulate huge numbers of orifice and dynamic grid to set the vibration parameters.The aim of this research is to obtain the numerical simulation result of temperature and flow field by analysis of fluid situation and heat transfer law in vibrated fluid bed based on the theory of fluid mechanics and heat transfer. The research result can optimize the drying process parameters obtained by design calculation about potassium chloride salt, which can also put forward a new research method for the improvement and optimization of drying process.