锥形流化床水平射流条件下的流化特性

Fluidization characteristics of horizontal jet of conical fluidized bed

在一个160 mm×300(20)mm×30 mm(高×宽×厚)、锥角为60°的二维锥形流化床中研究了两侧水平射流条件对3种不同粒径颗粒流化特性的影响。临界流化曲线结果表明:压降随着流量增大而迅速升高,到达一个最大值后略有下降。另一方面通过实验观察,提出"沸腾核心"假设,并推导出颗粒达到起始流化状态时,流速沿床层高度的变化规律。在假设的基础上,根据厄贡方程推导得出最大压降的计算式,计算结果表明计算值略大于实验值。另外,实验中还发现二维锥形流化床的最小流化速度随颗粒粒径增大而增大,随填料体积的增大也略有增大。

The influences of two sides horizontal jet on the fluidization characteristics of three different-sized particles were studied by using a two-dimensional conical fluidized bed with the size of 160 mm ×300（20） mm× 30 mm （height × width × thickness） and cone angle of 60° The critical fluidization curve showed that pressure drop increased rapidly with increasing flow rate and decreased slightly after reaching a maximum. On the other hand,the hypothesis of“boiling core”was proposed based on experimental observations,and the change of flow rate with variation of bed height when the particles reached an incipient fluidization state was deducted. Based on the hypothesis,the calculation equation of maximum voltage drop was deducted according to the Ergun equation,and the calculation results showed that the calculated values were slightly higher than the experimental values. In addition,the minimum fluidization velocity of the two-dimensional conical fluidized bed increased with increasing particle size,but increased slightly with increasing filler volume.