DEM-Based Models for Solids Exchange in a Pant Leg Fluidized Bed
Understanding the behaviors of solids exchange between two half beds in a pant leg fluidized bed is crucial in proper design,scale up and operation.DEM models based on Eulerian-Lagrange have shown promise in gaining this understanding.The power spectrum density (PSD) analysis was used to get the dominant frequency of the differential pressure fluctuations in experiments and the difference of particle number in simulations.The experiments were carried out in the pant leg fluidized bed with dimensions of 0.24m width,0.02m depth,0.8m height and 0.16m pant leg height.The black glass particles with diameters of 0.9-lmm were adopted as bed materials.The effects of fluidization velocity and static bed height on the solids exchange were studied.The amplitudes of fluctuations both in experiments and in simulations show that amount of particles for exchange between two half beds increases with increasing fluidization velocity.The PSD analysis show that two dominant frequencies are gotten at about 0.5-1Hz and 2.6-3.2Hz for experiments and 1Hz and 3 Hz for simulations at higher fluidization velocity.The first and second dominant frequencies correspond to the behavior of solids exchange in the form of clusters or strands and to both bubbling action and solids exchange in the form of single particles respectively.With increasing fluidization velocity,the effect of variations of bed inventory on pressures increases for the simulation cases,while the bubbling action on pressure fluctuations is weakened,and the energy of two dominant frequencies caused by solids exchange only in the form of both clusters and single particles increased.The higher static bed height contributed more particles to exchanging between two half beds in the form of clusters periodically.
solids exchange pant leg fluidized bed DEM power spectrum density
Chunzhen Yang Yufeng Duan Haitao Hu
School of Energy and Environment,Southeast University,Nanjing,210096,China
国际会议
The 7th International Symposium on Coal Combustion(第七届国际煤燃烧学术会议)
哈尔滨
英文
436-442
2011-07-19（万方平台首次上网日期，不代表论文的发表时间）