Numerical simulation of mechanical mixing in high solid anaerobic digester.

Computational fluid dynamics (CFD) was employed to study mixing performance in high solid anaerobic digester (HSAD) with A-310 impeller and helical ribbon. A mathematical model was constructed to assess flow fields. Good agreement of the model results with experimental data was obtained for the A-310 impeller. A systematic comparison for the interrelationship of power number, flow number and Reynolds number was simulated in a digester with less than 5% TS and 10% TS (total solids). The simulation results suggested a great potential for using the helical ribbon mixer in the mixing of high solids digester. The results also provided quantitative confirmation for minimum power consumption in HSAD and the effect of share rate on bio-structure.

[1]  Jie Ding,et al.  CFD optimization of continuous stirred-tank (CSTR) reactor for biohydrogen production. , 2010, Bioresource technology.

[2]  Jie Wu,et al.  Performance analysis of axial‐flow mixing impellers , 2000 .

[3]  Nigel Grigg,et al.  Comparison of Computation Fluid Dynamics Simulation against Tracer Data from a Scale Model and Full-Sized Waste Stabilization Pond , 2008 .

[4]  H. Landry,et al.  PHYSICAL AND RHEOLOGICAL PROPERTIES OF MANURE PRODUCTS , 2004 .

[5]  M. Himmel,et al.  Horsepower requirements for high-solids anaerobic digestion , 1995 .

[6]  Grietje Zeeman,et al.  Rheological properties of dairy cattle manure. , 2005, Bioresource technology.

[7]  S. Nagata,et al.  Power Characteristics of Mixing Impellers , 1956 .

[8]  Lasse Rosendahl,et al.  Co-firing straw with coal in a swirl-stabilized dual-feed burner: modelling and experimental validation. , 2010, Bioresource technology.

[9]  E. Cristiani-Urbina,et al.  Removal of hexavalent chromium by Trichoderma viride in an airlift bioreactor , 2006 .

[10]  L. Torres,et al.  Rheological characterization of primary and secondary sludges treated by both aerobic and anaerobic digestion , 1997 .

[11]  Philip R. Goodrich,et al.  Rheological properties of Moroccan dairy cattle manure , 1992 .

[12]  M H Al-Dahhan,et al.  Anaerobic digestion of animal waste: waste strength versus impact of mixing. , 2005, Bioresource technology.

[13]  Binxin Wu,et al.  CFD simulation of non‐Newtonian fluid flow in anaerobic digesters , 2008, Biotechnology and bioengineering.

[14]  A. Gosman,et al.  PREDICTION OF IMPELLER- INDUCED FLOW IN MIXING VESSELS USING MULTIPLE FRAMES OF REFERENCE , 1994 .

[15]  M. Himmel,et al.  Development of a novel laboratory scale high solids reactor for anaerobic digestion of processed municipal solid wastes for the production of methane , 1989 .

[16]  I Angelidaki,et al.  Anaerobic degradation of solid material: importance of initiation centers for methanogenesis, mixing intensity, and 2D distributed model. , 2005, Biotechnology and bioengineering.

[17]  Da-Wen Sun,et al.  Applications of computational fluid dynamics (CFD) in the modelling and design of ventilation systems in the agricultural industry: a review. , 2007, Bioresource technology.

[18]  L. T. Angenent,et al.  Effect of shear on performance and microbial ecology of continuously stirred anaerobic digesters treating animal manure , 2008, Biotechnology and bioengineering.

[19]  Martha Salcudean,et al.  Computational modelling of large aerated lagoon hydraulics. , 2007, Water research.

[20]  M H Al-Dahhan,et al.  Anaerobic digestion of animal waste: effect of mixing. , 2005, Bioresource technology.

[21]  A. Rasmuson,et al.  Energy dissipation and macro instabilities in a stirred square tank investigated using an LE PIV approach and LDA measurements , 2005 .

[22]  Ruihong Zhang,et al.  Biogas production from municipal solid wastes using an integrated rotary drum and anaerobic-phased solids digester system. , 2010, Bioresource technology.

[23]  E. L. Paul,et al.  Handbook of Industrial Mixing , 2003 .

[24]  Michael E. Himmel,et al.  Anaerobic digestion of processed municipal solid waste using a novel high solids reactor: Maximum solids levels and mixing requirements , 2005, Biotechnology Letters.

[25]  Ashwin W. Patwardhan.  Prediction of flow characteristics and energy balance for a variety of downflow impellers , 2001 .

[26]  Michael W. Chudacek.  Impeller power numbers and impeller flow numbers in profiled bottom tanks , 1985 .

[27]  A. B. Metzner.  Agitation of non‐Newtonian fluids , 1957 .

[28]  Hiroshi Takahashi,et al.  CFD simulation of mixing in anaerobic digesters. , 2009, Bioresource technology.