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过程工程学报 ›› 2021, Vol. 21 ›› Issue (4): 420-430.DOI: 10.12034/j.issn.1009-606X.220332

• 流动与传递 • 上一篇    下一篇

气-固微型流化床压降特性及最小流化速度的实验研究

史亚琪1, 李彦君1,2*, 杜玉朋1,2, 任万忠1,2   

  1. 1. 烟台大学化学化工学院,山东 烟台 264005 2. 烟台大学轻烃资源化综合利用协同创新中心,山东 烟台 264005
  • 收稿日期:2020-10-12 修回日期:2021-02-08 出版日期:2021-04-22 发布日期:2021-04-28
  • 通讯作者: 李彦君
  • 基金资助:
    燃煤超细微粒的生成与控制机理研究

Experimental study on pressure drop characteristics and minimum fluidization velocity of gas-solid micro-fluidized bed

Yaqi SHI1, Yanjun LI1,2*, Yupeng DU1,2, Wanzhong REN1,2   

  1. 1. College of Chemistry & Chemical Engineering, Yantai University, Yantai, Shandong 264005, China 2. Collaborative Innovation Center for Comprehensive Utilization of Light Hydrocarbons, Yantai University, Yantai, Shandong 264005, China
  • Received:2020-10-12 Revised:2021-02-08 Online:2021-04-22 Published:2021-04-28

摘要: 在内径3~20 mm的4个气?固微型流化床中,分别考察了A类和B类两种类型颗粒的流化特性,同时研究了床几何结构、操作条件、物相性质等各因素对其最小流化速度的影响。结果表明,气?固微型流化床中的床层压降特性与颗粒类型密切相关,不同的流动状态下两种类型颗粒的流动特性存在显著地差异。在固定床阶段,与B类颗粒相比,A类颗粒与壁面间的相互作用更强,导致实验压降值偏离计算值更大;在流化床阶段,较大颗粒粒径和密度的B类颗粒在床层内表现出了更高的气泡聚并和破裂程度,加剧了颗粒间的碰撞,增加了能量损失,从而形成了较高的实验压降。气?固微型流化床的最小流化速度除了与操作条件和物相性质有关外,床内径与静态床层高度对其也会产生显著影响。随着床径减小及静态床高增加,最小流化速度逐渐增加。综合考察各影响的因素,提出了适用于实验考察范围内预测微型流化床最小流化速度的经验关联式。

关键词: 气-固微型流化床, 床径, 静床高, 压降特性, 最小流化速度

Abstract: The fluidization characteristics of Geldart group A and Geldart group B particles were investigated in four gas?solid micro fluidized beds with different inner diameters ranging from 3 to 20 mm, respectively. At the same time, the variation rules of the minimum fluidization velocity affected by some important factors, such as bed geometry, operating conditions and physical-phase properties were studied. The result showed that the bed pressure drop characteristics in the gas?solid micro fluidized bed were closely related to the used particle type, and the flow characteristics of two types of particles were significantly different under various flow states. In the fixed bed stage, compared with Geldart group B particle, the interaction between the A particles and the wall was stronger, leading to greater deviation of the experimental pressure drop value from the calculated value derived from the pressure formula of traditional fluidized beds. While in the fluidized bed stage, the larger particle size and density of Geldart group B particles showed higher bubble coalescence and rupture degree in the fluidized bed, which intensified the collision among different particles and increased the energy loss, as a result the pressure drop of the whole fluidized beds showed a higher experimental value. The minimum fluidization velocity of the gas?solid micro fluidized bed was not only related to the general operating conditions and gas/solid phase properties but also influenced observably by the inside diameter and the height of the static bed. The minimum fluidization velocity increased gradually with the decreased of bed diameter and increased of the static bed height. An empirical correlation to predict the minimum fluidization velocity of the micro fluidized bed was proposed within the scope of the experimental investigation under the condition of some important influencing factors.

Key words: gas-solid micro-fluidized bed, bed diameter, static bed height, pressure drop characteristics, minimum fluidization velocity