摘要
本文采用了随机过程的分析方法,提出了一个描述浅层气—固流化床中固体粒子混合的一般化数学模型方程,并在一横截面积为300×500mm 的矩形浅层流化床中,以同类含盐粒子为示踪粒子进行了试验。试验是在固体粒子不作宏观流动的分批式操作条件下进行的,试验范围较宽。以所提出的数学模型方程拟合实验数据,和采用了最优化方法得到固体粒子的轴向离散系数 D 与操作参数和床层结构参数之间的无因次形式的定量关系如下:ρDD/μ=0.0886(W/L)^(1.120)(H_0/L)^(1.405)(ρU_0■/μ)^(2.907)/(ρ_2/ρ)^(4.740)(■/L)^(6.606)由所得的17组实验数据表明,实验的和计算的 D 值之间的平均偏差在10%以内,最大偏差为19%。已发表的一些文献值亦落在上述偏差范围之内。但本研究工作的实验范围较宽,特别是包括了床层的几何结构等因素,而在文献中,尚未见过有详细报导。
In this work,we developed a general mathematical model to describe the particle mixing in shallow fluidized beds by using an approach of stochastic processes.Mixing experiments were carried out in a rectangular and shallow fluidized bed with a cross sectional area of 300×500mm under batch operating conditions.The experimental range was relatively wide,covering a variety of geometric structures of the bed layer containing salt sample particles as tracers,which were prepared from the same kind of fluidizing particles。 By fitting the experimental data to the proposed model with the aid of an optimization technique,the axial dispersion coefficients of the solid particles in the bed were obtained.A regressive formula for the axial dispersion coefficient in dimensionless form was obtained as follows: ((ρD)/μ =(0.0886(W/L)^(1.120)(H_o/L)^(1.405)(ρU_o_p)^(2.907))/((ρ_s/ρ)^(4.704)(_p/L^(6.606))) Comparsion of the experimental results with thoge calculated showed an ave- rage deviation of about 10%,and maximum deviation<19%.It was also found that the proposed formula can fit the data of the literature.Their experi- mental ranges were narrower than ours,especially the geometric structure of the bed layer was not taken into account in their work.
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
1989年第4期40-50,共11页
Chemical Reaction Engineering and Technology
基金
国家自然科学基金
关键词
浅层流化床
床层
固体粒子
混合
Shallow Fluidized Bed
Mixing of Solid particles
Stochastic Model
