移动床空腔现象及空腔尺寸

Phenomenon of cavity and its size in rectangular moving-bed

移动床由于具有独特优越性得到广泛应用,但其流量受到空腔现象的影响.在二维矩形错流移动床内研究了移动床内的空腔现象,以两种物料及壁面材料对移动床内空腔现象的产生、发展进行考察.当错流气速或压力梯度足够大时移动床内将发生空腔,空腔大小随错流气速的增大而增大.并考察了空腔尺寸与错流气速的关系.在流体力学分析和力平衡分析的基础上推导出简化的空腔尺寸关联式,得出一个有多参数的非线性方程组,获得空腔尺寸与错流气速的关系,与实验数据基本吻合.

Moving bed is widely used in industry, but the range of the velocity of cross-flow gas is limited by a phenomenon of ＂cavity＂, which was investigated in a two-dimensional rectangular moving bed. The formation, developments of cavities in the moving bed were investigated and described with two particle materials and materials of wall. And the relationship between the size of a cavity and the velocity of crossflow gas was investigated. A cavity could be created when the velocity of cross-flow gas or the pressure gradient was high enough, and the size of a cavity increased with the increase of cross-flow gas velocity. Based on force balance, a simplified nonlinear equation group with multiple physical parameters that affect the size of a cavity was developed and the cavity size vs cross-flow gas velocity relationship thus obtained agreed with experimental data.