水车驱动式生物转盘氧传质模型的构建

Establishment of Oxygen Mass Transfer Modeling for Waterwheel Driving Rotating Biological Contactors

水车驱动式生物转盘将生物转盘与跌水充氧相结合,实现高效充氧。经理论分析与试验校核,为水车生物转盘建立氧传质模型。将水车生物转盘充氧过程简化为跌水过程充氧和盘片转动充氧两部分,对两部分分别建立模型。跌水过程以双膜理论为基础,从物料平衡角度建立氧传质模型。盘片转动过程以体积修正系数为基础,对Kim&Molof模型进行修正,建立充氧模型。二者结合,经理论推导与试验校正得出最终的水车生物转盘充氧模型。模型结果显示,水车生物转盘充氧能力与初始溶解氧浓度、跌水高度、盘片转速、装置尺寸及温度有关。此模型的建立为其他改进型生物转盘的氧传质模型的建立提供了有效依据和参考。

Waterwheel driving rotating biological contactors(wdRBCs)are designed combining water dropping contactor and rotating biological contactors(RBCs)for achieving high efficiency of oxygenation.In order to build the oxygen mass transfer model for wdRBCs,the mass transfer process of oxygen was simplified as two parts,including oxygenation in the process of water dropping and oxygenation in the process of the disks rotation.Based on the two-film theory,the section one of the model for water dropping was established through mass balance,the section two of this model for disks rotation was established by modifying the Kim&Molof model.Considering the two sections,the final wdRBCs oxygen mass transfer model was established through theoretical derivation and experimental correction.It showed that the oxygenation capacity was decided by initial DO,height,rotation rate,design of wdRBCs and temperature.Establishment of this model provide an effective reference for other modified RBCs.