Simulation and configuration correlation analysis of the self-agitation anaerobic baffled reactor for treating livestock organic waste

Abstract

A self-agitation anaerobic baffled reactor (SA-ABR) was designed for treating waste substrate. The system uses the produced biogas to create a level difference in the chambers for agitation without any mechanical equipment. Computational fluid dynamics (CFD) models were used to investigate the influence of different configurations on the tracer diffusion. The results show that each self-agitation cycle includes an energy storage process, an exergonic process and a buffer stage. The compound transition phenomenon mainly occurs during the energy exergonic process and buffer stage. A higher U-tube would decrease the diffusion of the influent. The liquid level significantly affects the mixing in the reactor. The incomplete self-agitation could be improved by decreasing the U-tube height, increasing the difference of the liquid levels or decreasing the U-tube length. Furthermore, the two-stage agitation allows the reactor to behave as a two-phase system and the compounds in the two stages could partially be mixed.