竖式移动床颗粒流动的研究

Study on Particle Flow in Shaft Moving Beds

竖式移动床内通常进行着伴随传热传质的化学反应,研究床层内颗粒流动对强化床层气固热交换和化学反应具有重要的意义.以球团竖炉为背景,采用实验与模拟相结合,研究床层内颗粒流动基本规律.动力学模型和黏性流模型是计算床层颗粒流动的主要模型,且黏性流模型更适用于竖炉;结合模拟与实验结果,确定了动力模型中的待定系数为0.02 m,黏性流模型中的黏性系数为0.15 Pa.s;采用黏性流模型模拟得到,球团在竖炉内流动比较均匀,接近于"活塞流";焙烧带的倾斜壁面倾角对炉内球团顺行起很大作用.

In a shaft moving bed, the heat and mass are generally transferred between particles and gases, besides the chemical reactions in it. It＇s of great significance to study the particle flow in the moving bed for intensifying heat exchange and chemical reactions. Making reference to PSF （pelletizing shaft furnace）, the rule of particle flow in the shaft moving bed was investigated combining experiments with simulation. The results showed that the kinematic model and viscous flow model are principal ones to simulate the particles flow, among which the viscous flow model is more applicable to PSF. And the appropriate value of the coefficient in the kinematic model may be fetched to be 0.02 m with the value of the viscous factor fetched 0.15 Pa·s. The simulation introducing the viscous flow model revealed that the pellets are flowing uniformly and approach to plug flow in PSF. The result also revealed that the inclination angle of tilting wall of PSF plays an important role in the parallel flow of particles in PSF.