【作者】 曹长青； 刘明言； 郭庆杰；

【Author】 CAO Chang-qing, LIU Ming-yan, GUO Qing-jie (College of Chem. Eng., Qingdao University of Science and Technology, Qingdao, Shandong 266042, Chnia; School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China)

【机构】 青岛科技大学化工学院； 天津大学化工学院；

【摘要】 应用开发的微电导探针测试技术,对聚乙烯颗粒(dp=4．01 mm,ρs=926 kg／m3)为固相,水、0．05％(ω)SCMC (羧甲基纤维素钠)及0．2%(ω)SCMC水溶液为液相,空气为气相的逆流三相湍动床的各相局部含率进行了同时测定, 获得了720套局部相含率实验数据．在表观气速Ug等于Ug3(颗粒在轴向均匀分布时的表观气速)时,实验发现:局部固含率(εs)呈现床中心处小,床壁处大的分布规律,且在r／R=0．75-0．90范围内有一个极大值峰,极大值峰出现的范围与传统流化床相比增大;局部气含率(εg)呈现床中心处最大,床壁处最小的分布规律,与传统流化床相比εg在径向上的非均匀性分布愈加明显．另外,建立了局部含率与操作条件、流体物性及径向位置的关联式,关联式的计算值与实验值吻合较好．更多还原

【Abstract】 Local phase holdups in an inverse three-phase turbulent bed are measured simultaneously by micro-electrical conductivity probe technique. The experiments are carried out with polyethylene particles (dp=4.01 mm,ρs=926 kg/m3), with air, and with water, 0.05%(ω) SCMC, 0.20%(ω) SCMC as solid phase, gas phase and liquid phase, respectively. 720 sets of experimental data of local phase holdups in radial direction are collected under Ug=Ug3. It is found that the distributions of local solid holdup in radial direction have a minimum value at the column center and a maximum value near the wall region, where a maximum peak is at r/R=0.75-0.90. The range of appearing maximum peak is larger than that of conventional fluidized beds. However, the distribution of local gas holdup is characterized by just reverse trend. The correlation of local phase holdups is a function of operation conditions and fluid physical properties as well as radial distances. The calculated values have good agreement with those measured experimentally.更多还原