Elutriation characteristics of multi-component mixtures in a fluidized bed pyrolysis process  

作　　者：Xing Wu Jingbo Peng Yu Zhang Zhiduo Wang 

机构地区：[1]Aeronautics Engineering College,Air Force Engineering University,Xi’an 710038,China

出　　处：《Particuology》2021年第5期131-138,共8页颗粒学报（英文版）

基　　金：the financial supports provided by the Natural Science Basic Research Program of Shaanxi(Program No.2020JQ-473).

摘　　要：Multi-component mixtures were prepared to simulate a bed of walnut shells undergoing pyrolysis in acold fluidized bed.Four mixtures with different ratios of walnut shell,semi-chars,and clean char were used.Batch elutriation experiments using these mixtures were performed in a transparent fluidized bed to allow direct observation of the flow patterns and particle composition.The results indicated that the bubble wake rather than bubble nose was primarily responsible for particle entrainment at higher gas velocities,and that coarser particles would be“transformed”into elutriable particles.Dimensionless gas velocities ranged from 0.2 to 1.0 and an exponential decrease in particle concentration with respect to bed height was observed.The transport disengagement height(TDH)gradually increased with the gas velocity until the entire bed layer enters a pneumatic transport state.Notably,larger TDHs were required when the bed contained a larger fraction of light components.Two characteristic parameters were used to evaluate particle elutriation:the elutriation rate constant(K),and the residual volatile content of the elutriated particles(v′).These parameters were used to optimize operating gas velocity for the fluidized bed.

关 键 词：Fluidized bed ELUTRIATION Multi-component mixture Walnut shell PYROLYSIS 

分 类 号：TQ028[化学工程]