The obtained results showed that the effect of external diffusion could be slackened by the decrease of fixed-bedvoidage and the increase of space velocity.
计算结果表明，银催化剂床层空隙率的减小或操作空速的增加有利于减弱该催化反应过程中外扩散效应的影响。
2
A comparison of VFB and CFB indicates that VFB has lower minimum fluidization velocity, higher bedvoidage and more steady fluidization because big bubbles can not be formed in the bed.
This paper reports some experimental results on variation of voidage in bed materials, bubble size and bubble rising velocity etc along the height of the bed.