采用脉冲示踪法在内置螺旋挡板冷态鼓泡流化床上研究了螺旋挡板、加料速率、流化风速、颗粒粒径和床料高度对颗粒在流化床内停留时间分布的影响. 结果表明，颗粒停留时间的无量纲方差从无螺旋挡板时的0.558减小到有螺旋挡板时的0.085，螺旋挡板可有效抑制颗粒返混，增大颗粒运动的平推流趋势；加料速率增大为约2倍时，停留时间减小为约50%，流动更趋向于平推流；床料高度增加，颗粒返混加剧，颗粒平均停留时间及无量纲方差均增大，颗粒运动向全混流靠近；随流化风速增大，颗粒平均停留时间变长；实验范围内，颗粒粒径对颗粒停留时间分布影响不大.
Effects of spiral internal, solid feeding rate, fluidized gas velocity, particle size and bed height on the particle residence time distribution were investigated in a cold bubbling fluidized bed using the tracer technique. The results showed that the dimensionless variance of particle residence time reduced from 0.558 without spiral internal to 0.085 with a spiral internal, indicating that the spiral internal helped restrain the back mixing of particles and made the flow approach the plug flow. When the solid feeding rate was doubled, the residence time of particles decreased by approximately 50% and the flow was closer to plug flow. As the increased bed height caused severe back mixing, both average residence time and dimensionless variance increased and the solid flow tended to be complete stirred flow. The average residence time of particles extended with the increasing of fluidized gas velocity. Particle size had a little effect on the residence time distribution under present experimental conditions.
[1]Babu M P, Setty Y P.Residence Time Distribution of Solids in a Fluidized Bed[J].Canadian Journal of Chemical Engineering, 2008, 81(1):118-123 [2]陈德明.钛精矿颗粒在内构件流化床内停留时间特性的研究[J].钢铁钒钛, 2007, 28(4):000006-000011 [3]Chen D M.Research on Residence Time of Panzhihua Ilmenite Particle in a Fluidized Bed with Inner Structural Parts[J].Iron Steel Vanadium Titanium, 2007, 28(4):000006-000011 [4]高巍, 张聚伟, 汪印, 等.连续进出料鼓泡流化床颗粒停留时间分布[J].过程工程学报, 2012, 12(1):9-13 [5]Gao W, Zhang J W, Wang Y, et al.Residence Time Distribution of Particles in a Bubbling Fluidized Bed with Their Continuous Input and Output[J].The Chinese Journal of Process Engineering, 2012, 12(1):9-13 [6] 毛元夫, 陈明强, 颜涌捷.连续运转的加压喷动流化床内颗粒停留特性 [J]. 过程工程学报, 1998(2):135-139.[J].过程工程学报, 1998, (2):135-139 [7]Mao Y F, Chen M Q, Yan Y J.Particle Residence Time in a Continuous Pressurized Spout Fluidized Bed [J]. The Chinese Journal of Process Engineering, 1998(2):135-139. [8]王锐思, 叶世超, 范辞冬, 等.内置水平管振动流化床停留时间分布模型[J].化学反应工程与工艺, 2010, 26(5):399-405 [9]Wang R S, Ye S C, Fan C D, et al.Mathematical Model of the Residence Time Distribution in Vibration Fluidized Bed with Inner-Horizontal Tubes[J].Chemical Reaction Engineering and Technology, 2010, 26(5):399-405 [10]叶世超, 陈晓东.固体返料气流-流化组合干燥器停留时间分布的研究[J].四川大学学报工程科学版, 2000, 32(1):17-20 [11]Ye S C, Chen X D.The Residence Time Distribution for Compound Dryer of Flash and Fluidization with Circulating Systems[J].Journal of Sichuan University (Engineering Science Edition), 2000, 32(1):17-20 [12] Zou Z, Zhao Y L, Zhao H, et al.Hydrodynamic and solids residence time distribution in a binary bubbling fluidized bed: 3D computational study coupled with the structure-based drag model [J]. Chemical Engineering Journal, 2017, 321:184-194. [13] Zou Z, Zhao Y L, Zhao H, et al.Numerical analysis of residence time distribution of solids in a bubbling fluidized bed based on the modified structure-based drag model [J]. Particuology, 2017, 32(6). [14]Hua L N, Wang J W, Li J H.CFD simulation of solids residence time distribution in a CFB riser[J].Chemical Engineering Science, 2014, 117(9):264-282 [15]Srinivasakannan C, Shoaibi A A, Balasubramanian N.Continuous Fluidized Bed Drying With and Without Internals: Kinetic Model[J].Chemical & Biochemical Engineering Quarterly, 2012, 26(2):97-104 [16]王勤辉, 骆仲泱, 倪明江, 等.循环流化床内颗粒停留时间分布[J].燃烧科学与技术, 2001, 7(4):221-225 [17]Wang Q H, Luo Z Y, Ni M J, et al.Particle Residence Time Distribution in a Circulating Fluidized Bed[J].Journal of Combustion Science and Technology, 2001, 7(4):221-225
