CIESC Journal ›› 2022, Vol. 73 ›› Issue (8): 3529-3540.DOI: 10.11949/0438-1157.20220166

• Fluid dynamics and transport phenomena • Previous Articles     Next Articles

Gas-liquid mass transfer coefficients in the gas-liquid-solid micro-fluidized beds

Kaiyue WANG1(), Yongli MA1(), Chen LI1, Mingyan LIU1,2   

  1. 1.School of Chemical Engineering, Tianjin University, Tianjin 300350, China
    2.State Key Laboratory of Chemical Engineering (Tianjin University), Tianjin 300350, China
  • Received:2022-02-07 Revised:2022-07-22 Online:2022-09-06 Published:2022-08-05
  • Contact: Yongli MA

气液固微型流化床的气液传质系数

王凯玥1(), 马永丽1(), 李琛1, 刘明言1,2   

  1. 1.天津大学化工学院,天津 300350
    2.化学工程联合国家重点实验室(天津大学),天津 300350
  • 通讯作者: 马永丽
  • 作者简介:王凯玥(1997—),女,硕士研究生,wangky97@163.com
  • 基金资助:
    国家自然科学基金项目(22178256)

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

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

CLC Number: