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过程工程学报 ›› 2023, Vol. 23 ›› Issue (6): 837-846.DOI: 10.12034/j.issn.1009-606X.222204

• 研究论文 • 上一篇    下一篇

二元颗粒在气固流化床中的轴向分布特性

闫珺1， 金伟星2， 范怡平2*， 鄂承林2， 卢春喜2， 孙富伟3   

  1. 1. 中国石油大学(北京)机械与储运工程学院，北京 102249 2. 中国石油大学(北京)化学工程与环境学院，北京 102249 3. 中国昆仑工程有限公司，北京 1000037
  • 收稿日期:2022-06-14 修回日期:2022-09-24 出版日期:2023-06-28 发布日期:2023-06-30
  • 通讯作者: 范怡平 fanyipin@yahoo.com
  • 基金资助:
    国家自然科学基金资助项目

Axial distribution characteristics of binary particles in a gas-solid fluidized bed

Jun YAN1,  Weixing JIN2,  Yiping FAN2*,  Chenglin E2,  Chunxi LU2,  Fuwei SUN3   

  1. 1. College of Mechanical and Transportation Engineering, China University of Petroleum, Beijing 102249, China 2. College of Chemical Engineering and Environment, China University of Petroleum, Beijing 102249, China 3. China Kunlun Contracting and Engineering Co., Ltd., Beijing 100037, China
  • Received:2022-06-14 Revised:2022-09-24 Online:2023-06-28 Published:2023-06-30

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摘要： 通过大型冷模实验测量了二元混合颗粒在流化床内沿轴向的压力分布，考察了混合颗粒截面平均浓度沿轴向的变化特点。通过分析床层压差分布的转折点，确定了密相区与稀相区的相交界面高度，根据实验结果给出了经验关联式。通过压力信号标准差分析了流化床内混合颗粒流化性能与表观气速和颗粒混合比例的关系。实验结果表明，平均颗粒浓度沿流化床轴向呈下降趋势，且在密相区中随表观气速增加而减小，在稀相区中随表观气速增大而增大。二元颗粒中大颗粒比例xl为0.685时，密相区总平均颗粒浓度存在最大值。密相区与稀相区相交界面高度随表观气速增大而提高。当0.225≤xl≤0.479和0.561≤ug≤1.122 m/s时，流化床内二元颗粒的流化性能和混合程度达到最佳。

关键词: 平均颗粒浓度, 标准差, 界面高度, 二元颗粒, 压力分布

Abstract: In order to achieve the goal of carbon peaking and carbon neutrality while taking into account the product yields of both gasoline and polyolefin, it is desirable to further optimize the polyolefin catalytic cracking technique by introducing two types of catalysts with distinct physical properties into the one reaction-regeneration system. Therefore, this work focuses on the flow and mixing characteristics of the binary particle system in a fluidized bed. The axial distribution of pressure in the binary particles fluidized bed was measured. The average solid concentration in the axial direction was investigated consequentially. The variation of the interface location between the dense phase and dilute phase zones was determined by analyzing the turning point of the axial profile of the differential pressure. An empirical coorelation was given based on the experimental results. Furthermore, the relationship of the fluidization performance of the binary particles in the fluidized bed to the gas velocity as well as the particle mixing ratio were discussed by investigating the standard deviation of pressure signal. The experimental results showed that the average particle concentration tended to decrease in the axial direction of the fluidized bed. The particle concentration decreased with an increasing of the superficial gas velocity in the dense-phase zone whereas it presented an increasing tendency in the dilute phase zone. The total average particle concentration in the dense-phase zone assumed a maximal value when the mixing ratio of big particle in the binary particles was 0.685. The interface height between the dense-phase and the dilute phase zones increased with an increasing of superficial gas velocity. It was also found that the fluidization performance and mixing degree of binary particles in the fluidized bed reached the best when 0.225≤xl≤0.479 and 0.561≤ug≤1.122 m/s.

Key words: mean particle concentration, standard deviation, interface height, binary particles, pressure distribution