挡板流化床中稳定湍流区的确定

CIESC Journal

挡板流化床中稳定湍流区的确定

李成钢,杨贵林

中国科学院山西煤炭化学研究所 ,中国科学院山西煤炭化学研究所

出版日期:1987-09-25 发布日期:1987-09-25

Determination of the Static Turbulent Fluidization Region in a Fluidized Bed with Baffles

Li Chenggang and Yang Guilin (Shanxi Institute of Coal Chemistry, Academia Sinica)

Online:1987-09-25 Published:1987-09-25

摘要/Abstract

摘要： 本文通过实验,在φ60mm的挡板流化床中考察了Geldart分类中B组颗粒的流化特性.根据流化床压降、压降的脉动、床层膨胀和气体停留时间分布,了解到床层的流化性质随流化气速的变化有比较明显的差异,可以划分为鼓泡流化区和湍流流化区.而由鼓泡流化区向湍流流化区过渡时存在着一个临界状态点,该点对应的气速称为临界湍流流化速度u_n,根据实验结果可关联出以下表达式:Re_n=0.1358ρ~(0.6576)Ga_ρ~(0.5120)其中:Re_n=u_nρ_fd_ρ|μ;Ga_ρ=d_ρ~3ρ_f~2g|μ~2ρ=ρ_s|ρ_f该式可作为粗颗粒挡板流化床中稳定湍流流化区的判据,其误差在10%以内.

Abstract: The characteristics of a 60 mm I. D. fluidized bed with baffles are studied using particles belonging to group B in Geldarts classifcation. Experimental results of pressure drop, pressure drop fluctuation bed expansion and RTD of gas show that the behavior of fluidization varies with changing gas velocity. Apparently it can be devided into two regions, i. e. bubbling and turbulent regions. It is suggested that a critical point exists between the bubbling and the turbulent regions, this point may be referred to as the critical turbulent fluidized point. The critical turbulent fluidization velocity un corresponding to this point can be expressed by the following equation: Ren = 0.1358p?6576GaP0.5120 inwhich, Ren=undppf/μ;Gap=dp3Pf2g/μ2; ρ=ρs/ρf This equation can be used as a criterion for the static turbulent fluidization region in fluidized beds with baffles. Its error is less than 10%.

李成钢,杨贵林. 挡板流化床中稳定湍流区的确定 [J]. CIESC Journal.

Li Chenggang and Yang Guilin (Shanxi Institute of Coal Chemistry, Academia Sinica). Determination of the Static Turbulent Fluidization Region in a Fluidized Bed with Baffles[J]. .