Effect of elevated temperature and silica sand particle size on minimum fluidization velocity in an atmospheric bubbling fluidized bed  

作　　者：A.Al-Farraji Haidar Taofeeq 

机构地区：[1]Chemical Engineering Department,College of Engineering,Al-Nahrain University,Baghdad,Iraq [2]Prosthetics and Orthotics Engineering Department,College of Engineering,Al-Nahrain University,Baghdad,Iraq

出　　处：《Chinese Journal of Chemical Engineering》2020年第12期2985-2992,共8页中国化学工程学报（英文版）

摘　　要：The impact of temperature and particle size on minimumfluidizing velocity was studied and analyzed in a small pilot scale of bubbling fluidized bed reactor.This study was devoted to providing some data about fluidization to the literature under high temperature conditions.The experiments were carried out to evaluate the minimum fluidizing velocity over a vast range of temperature levels from 20℃ to 850℃ using silica sand with a particle size of 300-425μm,425-500μm,500-600μm,and 600-710μm.Furthermore,the variation in the minimumfluidized voidage was determined experimentally at the same conditions.The experimental data revealed that the Umf directly varied with particle size and inversely with temperature,whileεmf increases slightly with temperature based on the measurements of height at incipient fluidization.However,for all particle sizes used in this test,temperatures above 700℃ has a marginal effect on Umf.The results were compared with many empirical equations,and it was found that the experimental result is still in an acceptable range of empirical equations used.In which,our findings are not well predicted by the widely accepted correlations reported in the literature.Therefore,a new predicted equation has been developed that also accounts for the affecting of mean particle size in addition to other parameters.A good mean relative deviation of 5.473% between the experimental data and the predicted values was estimated from the correlation of the effective dimensionless group.Furthermore,the experimental work revealed that the minimum fluidizing velocity was not affected by the height of the bed even at high temperature.

关 键 词：Minimum fluidization velocity VOIDAGE Elevated temperature Silica sand Fluidized bed Bed height 

分 类 号：TQ051.13[化学工程]