Mathematical Model of Three Dimensional Spouted Bed Using Distinct Element Method

S. Laorratanasak, Thongchai Rohitatisha Srinophakun, Parichat Mongkolsaowanit

Abstract


Spouted bed was simulated by a combining of Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) technique. In the simulation, DEM based on the Newton’s second law of motion was used to solve the particle motion and the fluid motion were obtained by CFD with the SIMPLE method and Upwind scheme. Programming was developed in Standard-C language and MATLABTM was used to visualize the results. The size of particles focused on this simulation is 2.5 mm in diameter (the density = 2,500 kg/m3, stiffness = 800 Nm -1). The time step used to maintain the stability of the simulation was 6.5 10-5 sec.

In this simulation, three levels of the static bed height were studied: 45, 58, and 70 mm. The operating parameter effects (the static bed height on the pressure drop across the bed and the minimum spouting velocity) were investigated. The pressure drop across the bed and the minimum spouting velocity increased corresponding to the level increment. In the study of the pulsed and multi-pulsed frequency, it was found that the higher number of frequency introduced the higher heat transfer to the particles. Moreover, the effect of each type of flow on the average particles temperature was studied. The continuous flow gave the highest average particles temperature. Even though, the single pulsed flow and the multiple pulsed flows gave the lower heat transfer than continuous flow, the multiple flows produced a very good distribution in the heat transfer and also can reduce the dead zone problem of the spouted bed.


Keywords


Spouted Bed / Distinct Element Method (DEM), Computational Fluid Dynamic (CFD), Heat Transfer

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References


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DOI: https://doi.org/10.24203/ajas.v7i1.5726

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