脉动流化床气泡特性的研究

为了研究脉动流化床气泡特性,对流化床内气泡的特性进行了二维冷态模拟实验．利用摄像机捕捉流化床气固瞬间的流动状态,通过对图像进行分析,比较了脉动流化床和传统流化床内气泡尺寸,探讨了气泡平均上升速度和气泡尺寸受脉动参数和物料特性的影响．从实验可知,脉动气流可以抑制大气泡的形成,促进气固间的接触,且气泡的平均上升速度随脉动频率的增加有降低的趋势．

Study of Bubble Characteristics in a Pulsed Fluidized Bed

In order to study bubble behavior in a pulsed fluidized bed,experiments for bubble behavior in a two-dimensional pulsed fluidized bed(PFB)were carried out.The instantaneous state of gas-solid flows in fluidized bed was caught by means of camera.By the medium of analysis of the images,the bubble size along the PFB was compared with that in a conventional fluidized bed.The bubble size and rising velocity were affected by the pulse parameters and the particle properties by image analysis.Results show that pulsating stream is possible to restrain large bubble formation and promote gas-solid contacting.And the bubble rising velocity was reduced with the frequency increased.