摘要
为了考察多孔筛板和单旋导向挡板组合对气固两相流动的作用效果,采用床层段内径为90 mm的三维流化床冷模装置,在表观气速(U_g)为0.04～1.14 m/s、初始装料高度(H)为650 mm的操作条件下,分析了自由流化床内气固两相流动特点,并对比分析了自由流化床、单旋流筛板式气固挡板流化床及双旋流筛板式气固挡板流化床压力脉动标准偏差和压差脉动标准偏差等参数,确立了旋流筛板式气固挡板有效抑制并破碎气泡的作用域。结果表明:旋流筛板式气固挡板有效抑制并破碎气泡的气速作用域为0.04 m/s≤U_g≤0.57 m/s,此时对应的自由流化床中气固两相处于鼓泡-节涌过渡流态化;轴向空间作用域为旋流筛板式气固挡板下方及包含旋流筛板式气固挡板的区域。增加旋流筛板式气固挡板的数量有助于强化破碎气泡的效果及拓宽其轴向空间作用域,但并不能拓宽破碎气泡的气速作用域。
Three-dimensional fluidized bed indifference device with inner diameter of 90 mm was adopted to investigate the effect of the combined porous sieve plates and single-rotation guide baffles on gas-solid two-phase flow.Under the operating conditions of superficial gas velocity(Ug)ranging from 0.04 to 1.14 m/s and initial loading height(H)of 650 mm,the scope of the rotating sieve tray type gas-solid baffle effectively suppressing and breaking bubbles was established by analyzing characteristics of gas-solid two-phase flow in free fluidized bed and comparing and analyzing standard deviation of pressure fluctuation and standard deviation of pressure difference pulsation in free fluidized bed,single-rotary sieve tray type gas-solid baffle fluidized bed and dual-rotation sieve tray type gas-solid baffle fluidized bed.The results showed that the scope of rotating sieve tray type gas-solid baffle effectively suppressing and breaking bubbles was 0.04≤Ug≤0.57 m/s,and at this time,the gas-solid two-phases in the corresponding free fluidized bed were in bubbling-slugging transitional fluidization.The scope of axial space was the area below the rotating sieve tray type gas-solid baffle and the area containing rotating sieve tray type gas-solid baffle.Increasing the number of rotating sieve tray type gas-solid baffle helped to strengthen the effect of breaking bubbles and to broaden its axial spatial extents,but it did not broaden the gas velocity range of broken bubbles.
作者
梁凯光
赵斌
王德武
时瑶
Liang Kaiguang;Zhao Bin;Wang Dewu;Shi Yao(School of Chemical Engineering,Hebei University of Technology,Tianjin 300130,China)
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
2018年第3期193-201,共9页
Chemical Reaction Engineering and Technology
基金
河北省自然科学基金资助项目(B2017202185)
关键词
气固两相流
流动特性
旋流筛板式气固挡板
破碎气泡
作用域
gas-solid two-phase flow
flow characteristics
rotating sieve tray type gas-solid baffle
break bubbles
scope
