Study on the Phase Holdup and
Gas-Liquid Mass Transfer Efficiency in Biological
Fluidised Bed 

　　　　　 XIE Cheng, CHEN Zhong-hao, SHU
Ming-jun, LI You-ming

( Paper Making & Pollution Control
Engineering Research Center, South China University of
Technology, GuangZhou 5l0641, China )

　　Abstract: Gas-liquid mass transfer
efficiency test with tap water and varied activated
carbon carrier addition at varying amount of inlet air
in an internal recycle three-phase biological fluidized
bed shows that when U_g≥0.75 m³/h,
the oxygen transfer efficiency in the fluidized bed can
be improved, the circulating time as well as the mixing
time can be reduced, and the air content can be
increased with the increase of air flow, while too high
an air flow (U_g≥1.1m³/h) is
unfavorable to the operation of the fluidized bed.
Increase of carrier addition will result in the
decreased oxygen transfer efficiency, shortened recycle
time, mixing time as well as the decrease of air
content.
　　Key words: inner recycle
Three-Phase Biological fluidized Bed; oxygen transfer
efficiency; air content

　　生物流化床技术是70年代以来兴起的新型高效污水处理技术。其中的内循环三相生物流化床反应器是比较广泛研究和使用的一种。
　　气相含率和液体循环速度是流化床反应器流体力学性能的两个重要参数，而传质特性主要通过体积氧传质系数来反映。反应器内混合强度及传质过程与液体循环速度及气相合率有很大关系，反应器结构参数对液体循环速度与气相含率及其分布有显著的影响。如何提高流化床内的混合强度和氧传递能力，使之适合于强需氧过程中、高浓度有机废水的处理是值得深入研究的课题。本文主要从气相含率、液体循环速度及体系氧传质系数来研究内循环三相生物流化床流体力学与传质特性，为放大设计与工程应用提供依据。

1 实验装置及方法

　　实验所用的内循环生物流化床反应器高1.1m，有效容积36L，由升流区、降流区和三相分离区组成，高径比（H／D）为
6.0，内外径比（D₁／D₂）为0.65，由有机玻璃制成。