湿颗粒流化床流动特性的实验研究

发布时间：2018-06-24 18:05

本文选题：湿颗粒 + 流化床　；参考：《工程热物理学报》2017年06期

【摘要】：基于可视化湿颗粒流化床实验系统,研究了多种Geldart-D类颗粒在不同含液量时的流动特性变化规律,包含流型、床层压降、最小流化速度。实验结果表明:1)在湿流化床内,颗粒出现聚团结块行为,气泡呈现不规则形状;湿颗粒流化过程的稳定性较干颗粒床明显下降,床内近壁面区域易出现局部沟流。2)固定床阶段,由于空隙率的增加,相同气速条件下,湿颗粒床层压降低于干颗粒;基于厄贡公式,得出了湿颗粒固定床床层压降的计算方法。3)湿颗粒的最小流化速度U_(mf)高于干颗粒,且随粒径d_p的增加而增加;导出了预测D类湿颗粒最小流化速度的半经验公式,Re_(mf)=0.279.Ar~(0.5),该式计算结果与实验测量结果偏差小于15%。
[Abstract]:Based on the visualization wet particle fluidized bed system, the flow characteristics of various Geldart-D particles with different liquid contents were studied, including flow pattern, bed pressure drop and minimum fluidization velocity. The experimental results show that in the wet fluidized bed, the particles exhibit the behavior of agglomeration and the bubbles show irregular shape, the stability of the fluidization process of the wet particles is obviously lower than that of the dry granular bed, and the local trench flow is easy to appear in the near wall region of the bed) in the fixed bed stage. Because of the increase of porosity, the pressure drop of wet particle bed is lower than that of dry particle under the same gas velocity. Based on Ergon formula, the calculation method of pressure drop of wet particle fixed bed is obtained. 3) the minimum fluidization velocity U _ (mf) of wet particle is higher than that of dry particle. The semi-empirical formula for predicting the minimum fluidization velocity of D type wet particles is derived, which is 0.279.Ar0.5. The deviation between the calculated results and the experimental results is less than 15.
【作者单位】：东南大学能源热转换及其过程测控教育部重点实验室能源与环境学院;东南大学-蒙纳士大学联合研究院颗粒系统仿真联合研究中心;澳大利亚蒙纳士大学化学工程系;
【基金】：国家自然科学基金重大项目(No.51390492);国家自然科学基金(No.51576046) 国家杰出青年科学基金(No.51325601)
【分类号】：TQ051.13

【相似文献】