推流反应器流速场对微孔曝气充氧能力的影响

Influence of Velocity Field Distribution on the Oxygenation Capacity of Fine Bubble Aeration in Plug-flow Reactor

文章针对推流式曝气池内水平流速对微孔曝气充氧能力影响问题,采用声学多普勒流速仪和溶解氧在线监测设备,研究了推流式反应器内流速场分布变化及其对刚玉微孔曝气器充氧能力的影响。结果表明,在模拟实际推流式反应器中,当断面平均流速从1 cm/s增加到3 cm/s和5 cm/s时,低通气量(25 m^3/(h·m^2),标准大气压下)条件下微孔曝气器的充氧性能提高了2.40%、8.60%,中通气量(37.5 m^3/(h·m^2),标准大气压下)条件下微孔曝气器的充氧性能提高了1.78%、4.76%,高通气量(50.0 m^3/(h·m^2),标准大气压下)条件下微孔曝气器的充氧性能提高了1.41%、3.52%;随着断面平均流速的增加,断面底部水平流速逐渐增加,并与微孔曝气器充氧能力呈显著相关性。

In order to solve the problem of the influence of horizontal flow velocity on the oxygenation capacity of fine bubble aeration in a plug-flow aeration tank, acoustic doppler velocimetry(ADV) and dissolved oxygen online monitoring equipment were used to study the change of velocity field distribution in the plug-flow reactor and its effect on the oxygenation capacity of corundum fine bubble diffusers. The results show that in the simulated actual plug-flow reactor, when the average flow velocity of the cross section increases from 1 cm/s to 3 cm/s and 5 cm/s, the oxygenation performance of the fine bubble diffusers is increased by 2.40% and 8.60% under the condition of low air flow rate 25 m3/(h·m2), the oxygenation performance of the fine bubble diffusers is increased by 1.78% and 4.76% under the condition of medium air flow rate37.5 m3/(h·m2) and the oxygenation performance of the fine bubble diffusers is increased by 1.41% and 3.52% under the condition of high air flow rate 50.0 m3/(h·m2). With the increase of the average flow rate of the section, the horizontal flow rate at the bottom of the section gradually increases, and it has a significant correlation with the oxygenation capacity(KLa20) of the fine bubble diffusers.