双组分大差异颗粒在气固流化床内混合/分离特性

doi:10.11949/0438-1157.20220890

摘要/Abstract

摘要：

实验考察了FCC催化剂(d_p=90 μm)和分子筛(d_p=1875 μm)构成的双组分大差异颗粒体系在流化床内的混合/分离特性。结果表明，在密相床层，随着大颗粒初始比例X₀逐渐增加，床层稀密相界面处的单位高度压降逐渐上升。双组分混合颗粒完全流化时密相床层内大颗粒质量分数在径向上总体分布均匀，但随着表观气速的增加大颗粒在径向上呈现出边壁高中心低的“U”形分布。全床混合均匀性在X₀<20.0%时较佳，且均匀性会随着表观气速u_g增加和X₀的增加而逐渐减小。在稀相空间，被夹带到稀相空间的大颗粒随着表观气速u_g增加逐渐增大，随着X₀的增大先增大后减小，当X₀=68.5%时夹带量最大。稀相空间内大颗粒质量分数在径向上呈“M”形分布，并且随着轴向高度的增加逐渐由“M”形分布转变为倒“U”形分布。基于实验结果，给出了计算完全混合高度和分级效率的经验关联式。

关键词: 流化床, 大差异颗粒, 颗粒分级, 多相流, 混合

Abstract:

The mixing/separation characteristics of the two-component large-difference particle system composed of FCC catalyst (d_p =90 μm) and molecular sieve (d_p =1875 μm) in fluidized bed were investigated experimentally. The results show that in the dense phase bed,pressure drop in unit height at the dilute dense phase interface will rise sharply with the gradual increase of the initial proportion of large particles X₀. At low gas velocity,the mass fraction of large particles in the dense phase bed is uniformly distributed in the radial direction. At high gas velocity,a “U” shape distribution with a high sidewall and low center appears. The whole bed mixing uniformity is better when X₀<20.0%,and the uniformity will gradually decrease with the increase of apparent gas velocity u_g and X₀. In the dilute phase space,entrained large particles gradually increase with the increase of u_g,and decrease with the increase of X₀. When X₀=68.5%,entrainment meets maximum. The mass fraction of large particles in the dilute phase space,in the radial direction, appears “M” shape distribution,and the “M” shape distribution will gradually change to inverted “U” type distribution with the increase of height. Based on the experimental results,the empirical correlations for calculating the total mixing height and separation efficiency are proposed.

Key words: fluidized bed, large difference particles, particle classification, multiphase flow, mixing

中图分类号:

TQ 052.5

金伟星, 闫珺, 鄂承林, 范怡平, 卢春喜. 双组分大差异颗粒在气固流化床内混合/分离特性[J]. 化工学报, 2022, 73(11): 4872-4883.

Weixing JIN, Jun YAN, Chenglin E, Yiping FAN, Chunxi LU. Mixing/separation characteristics of great different particles in gas-solid fluidized bed[J]. CIESC Journal, 2022, 73(11): 4872-4883.

图/表 15

图1 实验装置示意图1-罗茨鼓风机;2-缓冲罐;3-气体流量计;4-锥形气体分布底座;5-板式分布器;6-流化床;7-提升管;8-旋风分离器;9-旋风分离器料腿;10-松动风点

Fig.1 Schematic diagram of experimental setup

图2 颗粒粒度分布

Fig.2 PSD of particles

表1 颗粒基本物性参数

Table 1 Basic physical parameters of particles

颗粒种类

比表面平均粒径/

μm

颗粒堆密度/

(kg/m³)

颗粒密度/

(kg/m³)

最小流化速度/

(m/s)

带出气速/

(m/s)

图3 测点分布示意图1~9—测压点；10~17—采样点

Fig.3 Diagram of measuring points

图4 大颗粒初始比例

Fig.4 Initial proportion of large particles

图5 混合颗粒密度

Fig.5 Mixed particle density

图6 采样法准确性分析

Fig.6 Sampling accuracy analysis

图7 单位高度压降在轴向上的变化

Fig.7 Pressure drop in unit height

图8 表观气速ug对床层高度的影响

Fig.8 Effect of apparent gas velocity ug on bed height

图9 过渡区域

Fig.9 Transition area

图10 Xi 在密相区内的径向分布

Fig.10 Radial distribution of Xi in dense phase region

表2 混合均一性

Table 2 Mixing homogeneity

X₀/%	u_g/(m/s)
X₀/%	0.47	0.70	0.94	1.17
6.60	0.0030	0.0049	0.0048	0.0059
9.65	0.0080	0.0074	0.0063	0.0141
12.1	0.0053	0.0056	0.0101	0.0107
15.1	0.0079	0.0089	0.0048	0.0103
17.8	0.0076	0.0059	0.0104	0.0115
22.5	0.0055	0.0120	0.0114	0.0183
30.4	0.0110	0.0112	0.0107	0.0207
47.9	—	0.0158	0.0359	0.0447
68.5	—	0.0276	0.0186	0.0455
75.2	—	—	—	0.0387
86.9	—	—	—	0.0365

图11 混合指数随轴向高度的变化

Fig.11 Relationship between mixing index and axial height

图12 计算值回归值对比

Fig.12 Comparison of calculated value and regression value

图13 Xi 在稀相区内的径向分布

Fig.13 Radial distribution of Xi in dilute phase region

参考文献 31

1	刘春贵. 1000 kt·a^-1重油催化裂化装置焦炭产率升高的原因分析和对策[J]. 工业催化, 2020, 28(10): 66-70.
	Liu C G. Cause analysis and countermeasures for coke yield increase of 1000 kt·a^-1 heavy oil catalytic cracking unit[J]. Industrial Catalysis, 2020, 28(10): 66-70.
2	李铖,张荣. 催化裂化装置反应-再生系统热平衡问题分析及对策[J]. 工业催化, 2021, 29(7): 57-61.
	Li C, Zhang R. Analysis and countermeasures of heat balance in reaction regeneration system of FCC unit[J]. Industrial Catalysis,2021, 29(7): 57-61.
3	闫鸿飞. 催化裂解多产低碳烯烃工艺技术进展[J]. 现代化工, 2020, 40(12): 73-76.
	Yan H F. Process progress in catalytic cracking for more low-carbon olefins[J]. Modern Chemical Industry, 2020, 40(12): 73-76.
4	徐海丰. 2016年世界乙烯行业发展状况与趋势[J]. 国际石油经济,2017, 25(3): 101-106.
	Xu H F. Global ethylene industry in 2016 and its development trend[J]. International Petroleum Economics,2017,25(3): 101-106.
5	冯兴,郝明生. 催化裂解装置能耗分析及节能措施[J]. 炼油技术与工程, 2020, 50(7): 52-56.
	Feng X, Hao M S. Energy consumption analysis and energy saving measures of catalytic cracking unit[J]. Petroleum Refinery Engineering, 2020, 50(7): 52-56.
6	高金森, 卢春喜, 徐春明, 等. 一种双催化剂系统耦合再生工艺方法: 1624078A[P]. 2005-06-08.
	Gao J S, Lu C X, Xu C M,et al. Process for coupling regenerating of dual catalyst system: 1624078A[P]. 2005-06-08.
7	高金森, 徐春明, 曹斌, 等. 一种双反应再生系统多效耦合流化催化反应工艺方法: 1308419C[P]. 2007-04-04.
	Gao J S, Xu C M, Cao B, et al. Multiple effects coupled technical method of fluidization and catalytic reactions in dual reaction regeneration system: 1308419C[P]. 2007-04-04.
8	卢道铭, 唐钊艇, 范怡平, 等. 大差异颗粒分级再生设备的性能研究[J]. 化工学报,2021,72(8): 4184-4195.
	Lu D M, Tang Z T, Fan Y P,et al. Performance of large-difference-particle air classifier[J]. CIESC Journal,2021,72(8): 4184-4195.
9	丛义春, 徐春明, 高金森. 气固流化床中双组分颗粒分离的研究进展[J]. 石化技术, 2004, 11(4): 53-56.
	Cong Y C, Xu C M, Gao J S. Progress in study on binary particles segregation in gas-solid fluidized bed[J]. Petrochemical Industry Technology, 2004, 11(4): 53-56.
10	Rice R W, Brainovich J F. Mixing/segregation in two- and three-dimensional fluidized beds: binary systems of equidensity spherical particles[J]. AIChE Journal, 1986, 32(1): 7-16.
11	Nienow A W, Naimer N S, Chiba T. Studies of segregation/mixing in fluidised beds of different size particles[J]. Chemical Engineering Communications, 1987, 62(1/2/3/4/5/6): 53-66.
12	Peeler J P K, Huang J R. Segregation of wide size range particle mixtures in fluidized beds[J]. Chemical Engineering Science, 1989, 44(5): 1113-1119.
13	王芳, 欧阳洁, 张小华. 流化床中动态行为硬球模拟与软球模拟的比较[J]. 化工学报, 2006, 57(2): 281-287.
	Wang F, Ouyang J, Zhang X H. Comparison of dynamic behavior between hard-sphere and soft-sphere simulation in gas-solid fluidized beds[J]. Journal of Chemical Industry and Engineering (China), 2006, 57(2): 281-287.
14	Lacey P M C. Developments in the theory of particle mixing[J]. Journal of Applied Chemistry, 2007, 4(5): 257-268.
15	Lacey P M C. The mixing of solid particles[J]. Chemical Engineering Research and Design, 1997, 75: S49-S55.
16	Hogg R. Mixing and segregation in powders: evaluation, mechanisms and processes[J]. KONA Powder and Particle Journal, 2009, 27: 3-17.
17	孔行健, 孙国刚, 王茂辉, 等. 大差异双组分颗粒体系最小流化速度的研究[J]. 炼油技术与工程, 2008, 38(6): 10-14.
	Kong X J, Sun G G, Wang M H, et al. Experimental investigation on minimum fluidization velocity of great different particles in binary mixtures system[J]. Petroleum Refinery Engineering, 2008, 38(6): 10-14.
18	Das M, Meikap B C, Saha R K. Characteristics of axial and radial segregation of single and mixed particle system based on terminal settling velocity in the riser of a circulating fluidized bed[J]. Chemical Engineering Journal, 2008, 145(1): 32-43.
19	刘伟伟, 卢春喜, 范怡平, 等. 气固流化床中双组分混合颗粒的流态化特性[J]. 化工学报, 2008, 59(8): 1971-1978.
	Liu W W, Lu C X, Fan Y P, et al. Flow behavior of binary mixture particles in gas-solid fluidized beds[J]. Journal of Chemical Industry and Engineering (China), 2008, 59(8): 1971-1978.
20	张树青, 卢春喜, 时铭显, 等. 气固流化床中大差异双组分颗粒分级特性的实验研究[J]. 高校化学工程学报, 2007,21(2): 245-250.
	Zhang S Q, Lu C X, Shi M X, et al. Segregation of binary particle with significant size difference in gas-solid fluidized beds[J]. Journal of Chemical Engineering of Chinese Universities, 2007, 21(2): 245-250.
21	曹斌. 大差异多元颗粒气固流化床流动规律的研究[D]. 北京:中国石油大学(北京), 2006.
	Cao B. Study on the flow behavior of gas-solid fluidized bed with large difference mixing particles[D]. Beijing: China University of Petroleum, 2006.
22	Noda K, Uchida S, Makino T, et al. Minimum fluidization velocity of binary mixture of particles with large size ratio[J]. Powder Technology, 1986, 46(2/3): 149-154.
23	Clift R, Rafailidis S. Interparticle stress,fluid pressure,and bubble motion in gas-fluidised beds[J]. Chemical Engineering Science, 1993, 48(9): 1575-1582.
24	耿超, 陈恒志. 双组分颗粒鼓泡流化床内气泡形状参数[J]. 化学反应工程与工艺, 2017, 33(2): 97-103.
	Geng C, Chen H Z. Bubble shape parameters of the bubbling fluidized bed with binary particles[J]. Chemical Reaction Engineering and Technology, 2017, 33(2): 97-103.
25	金涌. 流态化工程原理[M]. 北京: 清华大学出版社, 2001.
	Jin Y. Fluidization Engineering Principles[M]. Beijing: Tsinghua University Press, 2001.
26	Williams J C. The segregation of particulate materials: a review[J]. Powder Technology, 1976, 15(2): 245-251.
27	Rosato A, Strandburg K J, Prinz F,et al. Why the Brazil nuts are on top: size segregation of particulate matter by shaking[J]. Physical Review Letters, 1987, 58(10): 1038-1040.
28	Nienow A W, Rowe P N, Cheung L Y L. A quantitative analysis of the mixing of two segregating powders of different density in a gas-fluidised bed[J]. Powder Technology, 1978, 20(1): 89-97.
29	Hemati M, Spieker K, Laguérie C, et al. Experimental study of sawdust and coal particle mixing in sand or catalyst fluidized beds[J]. The Canadian Journal of Chemical Engineering, 1990, 68(5): 768-772.
30	Sharma A K, Tuzla K, Matsen J, et al. Parametric effects of particle size and gas velocity on cluster characteristics in fast fluidized beds[J]. Powder Technology, 2000, 111(1/2): 114-122.
31	赫俏, 陆继东, 张新文, 等. 循环流化床流动特性分析[J]. 燃烧科学与技术, 1999, 5(3): 325-330.
	He Q, Lu J D, Zhang X W, et al. Study on the fluid characteristics of circulating fluidized bed[J]. Journal of Combustion Science and Technology, 1999, 5(3): 325-330.

[1]	陈爱强, 代艳奇, 刘悦, 刘斌, 吴翰铭. 基板温度对HFE7100液滴蒸发过程的影响研究[J]. 化工学报, 2023, 74(S1): 191-197.
[2]	谈莹莹, 刘晓庆, 王林, 黄鲤生, 李修真, 王占伟. R1150/R600a自复叠制冷循环开机动态特性实验研究[J]. 化工学报, 2023, 74(S1): 213-222.
[3]	宋瑞涛, 王派, 王云鹏, 李敏霞, 党超镔, 陈振国, 童欢, 周佳琦. 二氧化碳直接蒸发冰场排管内流动沸腾换热数值模拟分析[J]. 化工学报, 2023, 74(S1): 96-103.
[4]	杨越, 张丹, 郑巨淦, 涂茂萍, 杨庆忠. NaCl水溶液喷射闪蒸-掺混蒸发的实验研究[J]. 化工学报, 2023, 74(8): 3279-3291.
[5]	程小松, 殷勇高, 车春文. 不同工质在溶液除湿真空再生系统中的性能对比[J]. 化工学报, 2023, 74(8): 3494-3501.
[6]	汪尔奇, 彭书舟, 杨震, 段远源. 含HFO混合体系气液相平衡的理论模型评价[J]. 化工学报, 2023, 74(8): 3216-3225.
[7]	黄可欣, 李彤, 李桉琦, 林梅. 加装旋转叶轮T型通道流场的模态分解[J]. 化工学报, 2023, 74(7): 2848-2857.
[8]	董明, 徐进良, 刘广林. 超临界水非均质特性分子动力学研究[J]. 化工学报, 2023, 74(7): 2836-2847.
[9]	杨峥豪, 何臻, 常玉龙, 靳紫恒, 江霞. 生物质快速热解下行式流化床反应器研究进展[J]. 化工学报, 2023, 74(6): 2249-2263.
[10]	郑志航, 马郡男, 闫子涵, 卢春喜. 提升管射流影响区内压力脉动特性研究[J]. 化工学报, 2023, 74(6): 2335-2350.
[11]	陈巨辉, 张谦, 舒崚峰, 李丹, 徐鑫, 刘晓刚, 赵晨希, 曹希峰. 基于DEM方法的旋转流化床纳米颗粒流动特性研究[J]. 化工学报, 2023, 74(6): 2374-2381.
[12]	张媛媛, 曲江源, 苏欣欣, 杨静, 张锴. 循环流化床燃煤机组SNCR脱硝过程气液传质和反应特性[J]. 化工学报, 2023, 74(6): 2404-2415.
[13]	张艳梅, 袁涛, 李江, 刘亚洁, 孙占学. 高效SRB混合菌群构建及其在酸胁迫条件下的性能研究[J]. 化工学报, 2023, 74(6): 2599-2610.
[14]	姚晓宇, 沈俊, 李健, 李振兴, 康慧芳, 唐博, 董学强, 公茂琼. 流体气液临界参数测量方法研究进展[J]. 化工学报, 2023, 74(5): 1847-1861.
[15]	党玉荣, 莫春兰, 史科锐, 方颖聪, 张子杨, 李作顺. 综合评价模型联合遗传算法的混合工质ORC系统性能研究[J]. 化工学报, 2023, 74(5): 1884-1895.