气液固微型流化床的气液传质系数

doi:10.11949/0438-1157.20220166

摘要/Abstract

摘要：

气液固微型流化床兼具微流控系统和宏观流化床的优点，具有潜在的工业应用价值，但是，其应用基础研究十分缺乏。采用床径为1.6、2.0、2.4 mm的微型流化床，平均粒径为160、190、220 μm的玻璃珠，以NaOH水溶液吸收CO₂气体为气液传质研究物系，在三相流动研究的基础上，考察了表观气速、表观液速、床径、粒径等对三相微型流化床气液体积传质系数的影响。结果表明：给定其他条件，增加表观气速和表观液速，均使气液体积传质系数增大；表观气速主要改变气含率和气液相界面积，而表观液速主要改变液相传质系数；床径减小，气液相界面积和气液体积传质系数都有所增加；在气液两相微型鼓泡塔中加入固体颗粒，形成三相分散鼓泡流型，当其固含率在0.15~0.30范围内，可显著增强气液传质，其气液体积传质系数是气液微鼓泡塔的1.1~1.5倍；与宏观流化床相比，相同条件下微型床的相界面积为它的5~10倍，是微型流化床具有更大体积传质系数的主要影响因素。

关键词: 气液固, 微型流化床, 气液, 微鼓泡塔, 传质系数, 流态化

Abstract:

Gas-liquid-solid micro-fluidized bed combines the advantages of microfluidic system and macro-fluidized bed, and has potential industrial application value, but its application basic research is very lacking. The effects of several conditions including superficial gas velocity and liquid velocity, bed diameter, size of solid particles on the volumetric and liquid-phase gas-liquid mass transfer coefficients of CO₂ absorption by NaOH solution were studied by using the three-phase micro-fluidized bed made of 1.6, 2.0, 2.4 mm capillary tubes and solid particles with diameters of 160, 190 and 220 μm based on the investigations of gas-liquid-solid flows. The results show that the gas-liquid volumetric mass transfer coefficient increases with the increase of the superficial gas velocity and liquid velocity, in which the change of superficial gas velocity mainly affects the gas holdup and phase interface area, while the change of superfrical liquid velocity mainly affects the gas-liquid liquid-phase mass transfer coefficient. The mass transfer performance of the micro-fluidized bed with smaller bed diameter is the better, and its interface area and total gas-liquid mass transfer coefficient are enhanced. When solid particles are added into the gas-liquid mini-bubble column with solid holdup of 0.15—0.30 at three-phase bubbling flow regime, the gas-liquid volumetric mass transfer coefficient of this three-phase micro-fluidized bed is 1.1—1.5 times of that in gas-liquid mini-bubble column. Compared with the macro-fluidized bed, the interface area of micro-fluidized bed is 5—10 times of that of macro-fluidized bed under the same conditions, which is the main factor influencing the larger volume mass transfer coefficient of micro-fluidized bed.

Key words: gas-liquid-solid, micro-fluidized bed, gas-liquid, mini-bubble column, mass transfer coefficient, fluidization

中图分类号:

TQ 021

王凯玥, 马永丽, 李琛, 刘明言. 气液固微型流化床的气液传质系数[J]. 化工学报, 2022, 73(8): 3529-3540.

Kaiyue WANG, Yongli MA, Chen LI, Mingyan LIU. Gas-liquid mass transfer coefficients in the gas-liquid-solid micro-fluidized beds[J]. CIESC Journal, 2022, 73(8): 3529-3540.

图/表 18

图1 气液固微型流化床传质实验装置及流程1—液体入口; 2—液体泵; 3—气体入口; 4—气体流量计; 5—进气阀; 6—气瓶; 7—微型流化床主体部分; 8—液体出口; 9—高速摄像机; 10—微型计算机

Fig.1 Experimental setup and flowchart of mass transfer in the gas-liquid-solid micro-fluidized bed

图2 图片处理求取气含率过程

Fig.2 Image processing process

图3 气液固微型流化床中体积传质系数随表观气速的变化（dp=190 μm，T=25℃，D=2.0 mm, c(NaOH)=0.1 mol/L）

Fig.3 Variation of volumetric mass transfer coefficient with superficial gas velocity in gas-liquid-solid micro-fluidized bed

图4 不同表观气速下微型三相流化床内气泡流动状态(a) UG=2.370×10-3 m/s, UL=3.280×10-3 m/s, db=0.53 mm; (b) UG=4.560×10-3 m/s, UL=3.620×10-3 m/s, db=0.55 mm; (c) UG=6.720×10-3 m/s, UL=5.230×10-3 m/s, db=0.68 mm; (d) UG=7.580×10-3m/s, UL=4.870×10-3 m/s, db=0.71 mm

Fig.4 Flow patterns of gas bubbles in gas-liquid-solid micro-fluidized beds at different superficial gas velocities (D=2.0 mm, dp=190 μm)

图5 气液固微型流化床中的气液相界面积、气泡直径和气含率随表观气速的变化（dp=190 μm，T=25℃，c(NaOH)=0.1 mol/L）

Fig.5 Changes of gas-liquid phase interface area, bubble diameter and gas holdup with superficial gas velocity in gas-liquid-solid micro-fluidized bed

图6 气液固微型流化床液相传质系数随表观气速的变化（dp=190 μm，T=25℃，c(NaOH)=0.1 mol/L）

Fig.6 Changes of liquid-phase mass transfer coefficient with superficial gas velocity in gas-liquid-solid micro-fluidized bed

图7 气液固微型流化床液相传质系数随气泡直径的变化（UL=3.076×10-3 m/s,UG=4.587×10-3 m/s, D=2.0 mm，dp=190 μm，T=25℃，c(NaOH)=0.1 mol/L）

Fig.7 Changes of liquid-phase mass transfer coefficient with bubble diameter in gas-liquid-solid micro-fluidized bed

图8 气液固微型流化床中体积传质系数随表观液速的变化（dp=190 μm，T=25℃，c(NaOH)=0.1 mol/L）

Fig.8 Variation of volumetric mass transfer coefficient with superficial liquid velocity in gas-liquid-solid micro-fluidized bed

图9 不同表观液速下三相微型流化床内气泡流动状态(a) UG=5.240×10-3 m/s, UL=3.880×10-3 m/s, dp=190 μm, db=0.69 mm; (b) UG=5.180×10-3 m/s, UL=4.290×10-3 m/s, dp=190 μm, db=0.62 mm; (c) UG=5.760×10-3 m/s, UL=5.020×10-3 m/s, dp=190 μm, db=0.55 mm; (d) UL=4.290×10-3 m/s, dp=190 μm; (e) UL=5.020×10-3 m/s, dp=190 μm; (f) UL=4.290×10-3 m/s, dp=160 μm

Fig.9 Flow patterns of gas bubbles in gas-liquid-solid micro-fluidized beds at different superficial liquid velocities(D=2.0 mm)

图10 气液固微型流化床中的气液相界面积、气泡直径和气含率随表观液速的变化（dp=190 μm，T=25℃，c(NaOH)=0.1 mol/L）

Fig.10 Changes of phase interface area, bubble diameter and gas holdup with superficial liquid velocity in gas-liquid-solid micro-fluidized bed

图11 气液固微型流化床液相传质系数随表观液速的变化（dp=190 μm，T=25℃，c(NaOH)=0.1 mol/L）

Fig.11 Changes of liquid-phase mass transfer coefficient with superficial liquid velocity in gas-liquid-solid micro-fluidized bed

图12 气液固微型流化床体积传质系数随床径的变化（dp=190 μm，T=25℃，c(NaOH)=0.1 mol/L）

Fig.12 Changes of liquid-phase mass transfer coefficient with bed diameter in gas-liquid-solid micro-fluidized bed

图13 不同床径下三相微型流化床内气泡流动状态(a) UG=5.670 m/s, UL=3.280×10-3 m/s, D=2.4 mm, db=0.64 mm; (b) UG=6.130 m/s, UL=4.250×10-3 m/s, D=2.0 mm, db=0.56 mm; (c) UG=5.280 m/s, UL=4.060×10-3 m/s, D=1.6 mm, db=0.52 mm

Fig.13 Flow patterns of gas bubbles in gas-liquid-solid micro-fluidized beds at different bed sizes(dp=190 μm)

图14 气液微鼓泡塔与三相微型流化床体积传质系数比较（dp=190 μm，T=25℃，c(NaOH)=0.1 mol/L，D=2.0 mm）

Fig.14 Volumetric mass transfer coefficient between gas-liquid bubbling micro-column and gas-liquid-solid

图15 颗粒直径对气液固微型流化床体积传质系数的影响（T=25℃，c(NaOH)=0.1 mol/L）

Fig.15 Effect of particle diameter on volumetric mass transfer coefficient in gas-liquid-solid micro-fluidized bed

图16 表观气速改变时不同粒径气液固微型流化床的液相传质系数（T=25℃，c(NaOH)=0.1 mol/L，D=2.0 mm）

Fig.16 Liquid-phase mass transfer coefficients of gas-liquid-solid micro-fluidized bed with different particle sizes when superficial gas velocity changes

图17 表观液速改变时不同粒径气液固微型流化床的液相传质系数（T=25℃，c(NaOH)=0.1 mol/L，D=2.0 mm）

Fig.17 Liquid-phase mass transfer coefficients of fluidized beds with different particle sizes when superficial liquid velocity changes

图18 三相微型流化床中气泡与颗粒尺寸之比受流体速度的影响(T=25℃，c(NaOH)=0.1 mol/L，D=2.0 mm)

Fig.18 Effect of fluid velocity on the ratio of bubble diameter to particle diameter in gas-liquid-solid micro-fluidized bed

参考文献 27

1	Fan L S. Gas-Liquid-Solid Fluidization Engineering[M]. Boston: Butterworth-Heinemann, 1989.
2	Kashid M N, Kiwi-Minsker L. Microstructured reactors for multiphase reactions: state of the art[J]. Industrial & Engineering Chemistry Research, 2009, 48(14): 6465-6485.
3	Ye C B, Chen G W, Yuan Q. Process characteristics of CO₂ absorption by aqueous monoethanolamine in a microchannel reactor[J]. Chinese Journal of Chemical Engineering, 2012, 20(1): 111-119.
4	Li Y J, Liu M Y, Li X N. Minimum fluidization velocity in gas-liquid-solid minifluidized beds[J]. AIChE Journal, 2016, 62(6): 1940-1957.
5	Li Y J, Liu M Y, Li X N. Single bubble behavior in gas-liquid-solid mini-fluidized beds[J]. Chemical Engineering Journal, 2016, 286: 497-507.
6	Li Y J, Liu M Y, Li X N. Flow regimes in gas-liquid-solid mini-fluidized beds with single gas orifice[J]. Powder Technology, 2018, 333: 293-303.
7	Li X N, Liu M Y, Li Y J. Bed expansion and multi-bubble behavior of gas-liquid-solid micro-fluidized beds in sub-millimeter capillary[J]. Chemical Engineering Journal, 2017, 328: 1122-1138.
8	Li X N, Liu M Y, Ma Y L, et al. Experiments and meso-scale modeling of phase holdups and bubble behavior in gas-liquid-solid mini-fluidized beds[J]. Chemical Engineering Science, 2018, 192: 725-738.
9	Wang X Y, Liu M Y, Yang Z G. Coupled model based on radiation transfer and reaction kinetics of gas-liquid-solid photocatalytic mini-fluidized bed[J]. Chemical Engineering Research and Design, 2018, 134: 172-185.
10	Dong T T, Liu M Y, Li X N, et al. Catalytic oxidation of crotonaldehyde to crotonic acid in a gas-liquid-solid mini-fluidized bed[J]. Powder Technology, 2019, 352: 32-41.
11	Yao C Q, Zhu K, Liu Y Y, et al. Intensified CO₂ absorption in a microchannel reactor under elevated pressures[J]. Chemical Engineering Journal, 2017, 319: 179-190.
12	Zhu C Y, Guo H, Chu C Y, et al. Gas-liquid distribution and mass transfer of CO₂ absorption into sodium glycinate aqueous solution in parallel multi-channel microreactor[J]. International Journal of Heat and Mass Transfer, 2020, 157: 119943.
13	Zhang S Z, Zhu C Y, Feng H S, et al. Intensification of gas-liquid two-phase flow and mass transfer in microchannels by sudden expansions[J]. Chemical Engineering Science, 2021, 229: 116040.
14	Conlisk A T, McFerran J, Zheng Z, et al. Mass transfer and flow in electrically charged micro- and nanochannels[J]. Analytical Chemistry, 2002, 74(9): 2139-2150.
15	Zhang Y B. Efficient multiscale calculation results for microchannel mass transfer[J]. Scientific Reports, 2021, 11: 10023.
16	Dong T T, Ma Y L, Liu M Y. Gas-liquid mass transfer in the gas-liquid-solid mini fluidized beds[J]. Particuology, 2022, 69: 22-30.
17	Zahid Saima. 液-固微型流化床中的颗粒-液体间传质[D]. 天津: 天津大学, 2019.
	Saima Z. Mass transfer between solid particle and liquid flow in the liquid-solid mini-fluidized bed[D]. Tianjin: Tianjin University, 2019.
18	郝玲, 郑朝振, 章俊, 等. CO₂吸收模型中容积传质系数的确定[J]. 材料与冶金学报, 2012, 11(2): 98-101.
	Hao L, Zheng C Z, Zhang J, et al. Determination of volumetric mass transfer coefficient for CO₂ absorption model experiment[J]. Journal of Materials and Metallurgy, 2012, 11(2): 98-101.
19	刘燕, 张廷安, 赵洪亮, 等. CO₂微细气泡在NaOH溶液中吸收速率研究[J]. 过程工程学报, 2009, 9(S1): 185-188.
	Liu Y, Zhang T A, Zhao H L, et al. Study on absorption of CO₂ bubble disintegration in NaOH solution[J]. The Chinese Journal of Process Engineering, 2009, 9(S1): 185-188.
20	Inada S, Watanabe A. Effect of gas liquid properties on the absorption rate of CO₂ into NaOH solution[J]. Tetsu-to-Hagane, 1976, 62(7): 807-816.
21	Takemura F, Yabe A. Gas dissolution process of spherical rising gas bubbles[J]. Chemical Engineering Science, 1998, 53(15): 2691-2699.
22	Motarjemi M, Jameson G J. Mass transfer from very small bubbles—the optimum bubble size for aeration[J]. Chemical Engineering Science, 1978, 33(11): 1415-1423.
23	Lee J S, Jin H R, Lim H, et al. Interfacial area and liquid-side and overall mass transfer coefficients in a three-phase circulating fluidized bed[J]. Chemical Engineering Science, 2013, 100: 203-211.
24	Dani A, Guiraud P, Cockx A. Local measurement of oxygen transfer around a single bubble by planar laser-induced fluorescence[J]. Chemical Engineering Science, 2007, 62(24): 7245-7252.
25	Bischof F, Sommerfeld M, Durst F. The determination of mass transfer rates from individual small bubbles[J]. Chemical Engineering Science, 1991, 46(12): 3115-3121.
26	Doroodchi E, Peng Z B, Sathe M, et al. Fluidisation and packed bed behaviour in capillary tubes[J]. Powder Technology, 2012, 223: 131-136.
27	Tang C, Liu M Y, Li Y J. Experimental investigation of hydrodynamics of liquid-solid mini-fluidized beds[J]. Particuology, 2016, 27: 102-109.

[1]	江河, 袁俊飞, 王林, 邢谷雨. 均流腔结构对微细通道内相变流动特性影响的实验研究[J]. 化工学报, 2023, 74(S1): 235-244.
[2]	袁佳琦, 刘政, 黄锐, 张乐福, 贺登辉. 泡状入流条件下旋流泵能量转换特性研究[J]. 化工学报, 2023, 74(9): 3807-3820.
[3]	邢雷, 苗春雨, 蒋明虎, 赵立新, 李新亚. 井下微型气液旋流分离器优化设计与性能分析[J]. 化工学报, 2023, 74(8): 3394-3406.
[4]	高燕, 伍鹏, 尚超, 胡泽君, 陈晓东. 基于双流体喷嘴的磁性琼脂糖微球的制备及其蛋白吸附性能探究[J]. 化工学报, 2023, 74(8): 3457-3471.
[5]	高金明, 郭玉娇, 鄂承林, 卢春喜. 一种封闭罩内顺流多旋臂气液分离器的分离特性研究[J]. 化工学报, 2023, 74(7): 2957-2966.
[6]	江锦波, 彭新, 许文烜, 门日秀, 刘畅, 彭旭东. 泵出型螺旋槽油气密封泄漏特性及参数影响研究[J]. 化工学报, 2023, 74(6): 2538-2554.
[7]	刘起超, 周云龙, 陈聪. 起伏振动垂直上升管气液两相流截面含气率分析与计算[J]. 化工学报, 2023, 74(6): 2391-2403.
[8]	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.
[9]	董鑫, 单永瑞, 刘易诺, 冯颖, 张建伟. 非牛顿流体气泡羽流涡特性数值模拟研究[J]. 化工学报, 2023, 74(5): 1950-1964.
[10]	许文烜, 江锦波, 彭新, 门日秀, 刘畅, 彭旭东. 宽速域三种典型型槽油气密封泄漏与成膜特性对比研究[J]. 化工学报, 2023, 74(4): 1660-1679.
[11]	何万媛, 陈一宇, 朱春英, 付涛涛, 高习群, 马友光. 阵列凸起微通道内气液两相传质特性研究[J]. 化工学报, 2023, 74(2): 690-697.
[12]	白剑钊, 郭子轩, 王德武, 刘燕, 王若瑾, 唐猛, 张少峰. 摇摆对气液并流模式立体旋流筛板压降的影响研究[J]. 化工学报, 2023, 74(2): 707-720.
[13]	盛林, 昌宇, 邓建, 骆广生. 阶梯式T型微通道内有序气泡群的形成和流动特性研究[J]. 化工学报, 2023, 74(1): 416-427.
[14]	张童, 杨扬, 叶丁丁, 陈蓉, 朱恂, 廖强. 催化剂分布对可渗透阳极微流体燃料电池性能特性影响的研究[J]. 化工学报, 2022, 73(9): 4156-4162.
[15]	苏巧玲, 王军锋, 张伟, 詹水清, 吴天一. 低电导率工质中气泡的极化运动实验研究[J]. 化工学报, 2022, 73(9): 3861-3869.