Analysis of Flow Field in Sludge Digestion Reactor Based on Two Phase Flow Model
CAO Xiuqin
JIANG Kun
YIN Weiqi
XU Guoqing
Abstract：Sludge as an opaque non-Newtonian fluid, the research on flow field distribution in anaerobic digestion reactor has a guiding role to solve the problems of sludge accumulation and uneven mixing in the reactor. What's more, it can provide basis for the optimization of reactor design in practical engineering. Based on the solid-liquid two-phase flow model, the flow field in the sludge anaerobic digestion reactor was numerically simulated by CFD simulation software Fluent 15.0. The results showed that the distribution of velocity field relating to the height and radial distance. At a specific radial distance, the velocity increased gradually, and then gradually reduced to zero when diffused to the wall. The dead zone volume decreased gradually with the extension of time, whereas the descent rate was reduced. When t=1 s, the concentration of sludge at the height of Y=0.15 m was obviously larger than other heights within the scope of r/R as 0.3～0.5. When t=20 s, the sludge volume fraction reached about 10.5％ in the range of r/R as 0.5～0.9. The bottom, top and wall of the reactor are the areas with poor mixing effect. In addition, the pressure distribution on the blade surface was studied, and the result demonstrated that the pressure at the end of blade is the greatest.
Keywords：anaerobic digestionCFD simulationflow fieldvelocity distributionvolume fraction
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 120-125 )