充气喷动床流体力学性能的研究(Ⅱ)

STUDIES ON HYDRODYNAMICS OF SPOUTED BED WITH AERATION OF ANNULUS(Ⅱ)

本文在内径 92mm,按装了锥形不锈钢丝网底的有机玻璃床层内,以空气为喷动气体,分别以三种充气速率及三种填充高度,研究了硅胶、谷子、绿豆和尿素等四种颗粒物料充气喷动床的流动特性.在理论分析的基础上,通过实验获得了锥形底充气喷动床最小喷动气速及最大压降的无因次关联式1/1-ε d_pu_(ms)ρ/μ=0.25(L/D_t)^(0.38)(d_p/D_t)^(2.54)(D_i/D_t)^(0.33)(ρ(ρ_p-ρ)gD_t^3/μ~3)^(0.75)(d_pu_fρ/μ)^(-0.54)△P_M/((1-ε)(ρ_p-ρ)gL)=0.0516(L/D_t)^(0.46)(D_i/D_t)^(0.33)(d_pu_fρ/μ)^(1.25)

Hydrodynamics of the aerated spouted bed with a conical bottom of stainless steel screen was studied in a 92mm I.D.plexiglass column.Experiments were made by using four particulate materials(spherical silicagel,millet,green bead and urea),with three static bed depths for each materials,three aeration rates for each depths,and air as the medium for spouting and aeration.Based on the theoretical analysis,dimensionless empirical equations of minimum spouting velocity and peak pressure drop for aerated spouted bed with a conical bottom were obtained. 1/(1-ε)(d_pu_(ms)ρ)/μ=0.25(L/(D_t))^(0.38)(d_p/D_t)^(2.54)(D_i)/(D_t)^(2.54)(D_i/D_t)^(0.33)((ρ(ρ_p-ρ)gD_t^3)/μ~2)^(0.75)((d_pu_fρ)/μ)^(-0.54) (ΔP_M)/((1-ε)(ρ_p-ρ)gL)=0.0516(L/D_t)^(0.46)(D_i/D_t)^(0.33)((d_pu_fρ)/μ)^(1.25)