ABR反应器的结构参数对流动及混合特性的影响

为了改善ABR反应器的设计和运行,在实验室条件下,通过CFD(computational fluid dynamics,计算流体力学)技术和RTD(停留时间分布)曲线测试技术,分析不同结构参数下ABR反应器的流动和混合特性. 在此基础上,结合理论分析,确定ABR的最佳隔室数量. 结果表明:在反应器有效容积不变的情况下,随着ABR反应器内隔室数量由3个增至6个,ABR反应器内死区容积所占比例由15.51%降至1.87%,Pez(Peclet准数)由8.47升至16.67,N(串联数)由4.80升至8.88；隔室数量由3个增至4个、4个增至5个、5个增至6个时,死区容积所占比例的降幅分别为44.00%、74.50%、15.40%,Pez的增幅分别为36.88%、42.17%、32.57%,而N的增幅则分别为36.07%、1.95%、1.67%. 与5个隔室的ABR反应器相比,6个隔室的ABR反应器在死区容积所占比例、Pez和N等指标上尽管有所改善,但改善幅度已显著降低. 通过理论分析与混合参数模拟结果相结合,共同确定ABR反应器的最佳隔室数量为4个或5个. 

Influence of Structural Parameters of an ABR Reactor on Flow and Mixing Characteristics

The influence of anaerobic baffled reactor structure parameters on flow and mixing characteristics under laboratory conditions was studied to improve the design and operation of the reactor. The computational fluid dynamics (CFD) technique and the residence time distribution (RTD) curve were applied to simulate three-cell, four-cell, five-cell and six-cell reactor flow characteristics by inputting different structural parameters. The influence of the number of compartments on the flow and mixing characteristics of the reactor was investigated, and the optimum number was obtained with additional theoretical analysis. The results showed that for constant effective volume, as the number of the reactor compartments gradually increased from three to four, from four to five, from five to six, the percentage of dead zone was reduced from 15.51% in the three-cell reactor to 1.87% in the six-cell reactor, while the Pez parameter increased from 8.47 to 16.67, and the series number N increased from 4.80 to 8.88. As the number of reactor compartments increased from three to four, from four to five, from five to six, the reduction percentage of dead zone progressed from 44.00% to 74.50% to 15.40%, the Pez parameter progressed from 36.88% to 42.17% to 32.57%, and the series number N progressed from 36.07% to 1.95% to 1.67%. As compared to the five-cell reactor, the six-cell reactor had a relatively lower improvement in terms of dead zone percentage, Pez parameter and series number N. The optimum number of reactor compartments in the study was determined to be four or five via theoretical analysis and simulation. The adoption of the CFD technique and RTD curve for anaerobic baffled reactor mixing characteristics analysis will contribute to the hydraulic condition optimization in reactor design and operation.