改进型气升式内环流硝化反应器氧传递特性的研究  

Oxygen Transfer Characteristics in a Modified Internal-loop Airlift Nitrifying Bioreactor

作　　者：金仁村[1] 郑平[1] 王向东[2] 谢嘉[2] 

机构地区：[1]浙江大学环境工程系,浙江杭州310029 [2]四川大学建筑与环境学院,四川成都610065

出　　处：《高校化学工程学报》2006年第1期40-45,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金资助项目(30070017);浙江省重大攻关项目(2003C13005)

摘　　要：在废水处理领域，气升式内环流硝化反应器有着较好的应用前景；但其氧传递性能有待进一步改善。通过调整导流简直径以及导流简内静态混合元件的个数，试验了反应器结构对氧传递特性的影响。研究发现，当导流简直径取5．5cm，并在导流简内安装13个静态混合元件时，这种改进型硝化反应器的氧传递能力显著提高。在表观气速为5．05～23．80cm·s^-1。的条件下，测得氧传递系数为0．151～0．778min^-1，充氧能力为7．84～42．80g O2·h^-1，容积供氧能力为2．00-10．93kg O2·m^-3·d^-1，氧转移效率为39．2％～48．1％，氧转移动力效率为3．2～4．0kg O2·（kW·h）^-1,相对于普通气升式内环流硝化反应器，改进型内环流硝化反应器的氧传递系数、充氧能力、氧转移效率和氧转移动力效率都提高72.5％。根据Higbie渗透模型和Kolmogoroff各向同性理论，建立了氧传递系数与相关参数的关联式，预测值与试验结果相吻合，两者的相对误差为9．15％。Internal-loop airlift nitrifying bioreactor is a promising equipment in the field of wastewater treatment, but its performance of oxygen transfer needs to be improved. The effect of bioreactor configuration on the characteristics of oxygen transfer was investigated by using different size of draft tube diameter and varied number of static mixers inside the draft tube. The results show that the performance of oxygen transfer could be obviously improved when the diameter of draft tube is 5.5 cm and 13 static mixers is used. With superficial gas velocity of 5.05-23.80 cm·s^-1, the volumetric mass transfer coefficient 0.151 - 0.778 min^-1, oxygen transfer capacity 7.84 - 42.80 g O2·h^-1, volumetric oxygen transfer capacity 2.00 - 10.93 kg O2·m^-3·d^-1, oxygen transfer efficiency 39.2% - 48.1% and power efficiency of oxygen supply 3.2-4.0 kg O2·（kW·h）^-1 can be reached respectively. These indices are all 72.5% higher than those of the traditional nitrifying bioreactor. Based on Higbie＇s penetration theory and Kolmogoroff＇s theory of isotropic turbulence, a correlation equation between volumetric mass transfer coefficient and other parameters was established. The prediction values calculated from the above correlation equation are in good accordance with the experimental data.

关 键 词：气升式内环流硝化反应器 氧传递系数 氧转移效率 静态混合器 

分 类 号：X703.3[环境科学与工程—环境工程] TQ021.4[化学工程]