Effect of Stirring and Deflector Structure on Liquid Flow Characteristics in Integrated A2/O Unit

Di Peng ； Tao Zeng ； Xiangwan Xiao

《International Core Journal of Engineering》 7卷9期 (2021/09) Pp. 181-190

https://doi.org/10.6919/ICJE.202109_7(9).0028

摘要

For the developed fluidized bed-based integrated non-reflow A2/O process device, a gas, solid and liquid three-phase fluidized bed experimental platform was constructed for two compartments, and the Particle Image Velocimetry (PIV) technique was used to analyze the effect of long guide plate circulation orifice on liquid phase flow characteristics in fluidized bed. Furthermore, the liquid flow characteristics of the fluidized bed with a long (short) guide plate with a circulating orifice under different stirring or stirring aeration conditions and the axial velocity of the circulating orifice and the calculated loop flow were measured. The design of the mixed liquid reflux system is replaced by the guide plate circulation orifice and the operating conditions are optimized. The results show that the guide plate circulation orifice has the functions of reducing hydraulic concentration and dead zone and uniform hydraulic distribution, which is beneficial to sludge nucleation and shortening the A2/O start-up period. Under stirring conditions (1:1), fluidized bed liquid phase can form a stable circulation and has a more uniform hydraulic distribution and suitable hydraulic shearing force. Only long guide plates under stirring (1:1) aeration conditions,liquid phase near the plate can form a circulation, and the flow rate of the upper and lower circulation ports is greater than the design return flow. Prove that the design of the device is correct, and the optimal stirring condition is 1:1.

關鍵字

Fluidized Bed ； A2/O Process Device ； Liquid Flow Characteristic ； Hydraulic Distribution ； Optimum Stirring Condition ； PIV

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