U形管式流化床中下行段颗粒流动特性研究
CSTR:
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

河北省自然科学基金(B2022208045)


Study on particle-fluid flow characteristics in the downer of the U-bend tubular fluidized bed
Author:
Affiliation:

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    为解决煤热解过程中因荒煤气冷却冷凝造成的管道堵塞和废水处理难题,提出将煤热解炉释放的高温荒煤气直接进行催化裂化,使其中的稠环化合物转化为低沸点的单环化合物,并采用U形管式气固流化床作为裂化转化反应器。为研究该反应器内的颗粒流动特性,设计并搭建了冷模实验装置,在较低床层密度条件下,测定了下行段和上行段的轴向压力分布,并考察了颗粒循环量和空塔气速对下行段轴向与径向颗粒浓度即颗粒加和总体积占反应器体积的比例)及颗粒速度分布的影响。结果表明:下行段轴向压力自上而下逐渐增大,上行段则呈相反趋势;下行段轴向颗粒浓度先升高后平缓,且整体高于相同操作条件下的独立下行流化床;轴向颗粒速度沿流向逐渐降低;径向颗粒浓度分布呈现“密环”结构,颗粒速度在边壁处呈现下降的趋势。初步揭示了U形管式流化床的颗粒流体动力学特性,对后续的实验研究和反应器工程放大具有参考价值。

    Abstract:

    To address severe pipeline clogging and waste water issues caused by tar condensation during the cooling of raw coal pyrolysis gas, direct catalytic cracking of the hot raw gas from coal pyrolyzer was proposed in this study to convert the polycyclic compounds in tar into low-boiling-point monocyclic compounds. Furthmore, a U-bend tubular fluidized bed was introduced as the cracking reactor. To analyze the particle-flow dynamics in this reactor, a cold-flow model experimental setup was designed and constructed. Axial pressure profiles in both the downer section and riser sections were measured under relatively low bed densities. The effects of solid flux and superficial gas velocity on the axial and radial distributions of solid concentration (the ratio of the total volume of particles to the volume of the reactor) and particle velocity in the downer section were also investigated. The experimental results indicate that the axial pressure in the downer section increases gradually from top to bottom, while the opposite trend occurs in the riser section. In the downer section, the axial solid concentration first rises and then plateaus, exceeding that in a single downer under equivalent conditions. The axial particle velocity decreases in the direction of flow. Radially, the solid concentration exhibits a “dense annular” structure, and the particle velocity declines near the wall. This study offers fundamental insight into the particle hydrodynamics of the U-bend tubular fluidized bed, providing reference for subsequent experimental research and reactor scale-up.

    参考文献
    相似文献
    引证文献
引用本文

马健钧,高德宏,于浩然,王建英,李彦菊,胡永琪. U形管式流化床中下行段颗粒流动特性研究[J].河北科技大学学报,2025,46(6):632-640

复制
分享
相关视频

文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:2025-08-06
  • 最后修改日期:2025-09-03
  • 录用日期:
  • 在线发布日期: 2025-12-31
  • 出版日期:
文章二维码