Numerical Investigation of the Flow Characteristics of Slurry Manure in a Digestion Tank

Authors : Emre Aşkın Elibol

Pages : 49-67

View : 24 | Download : 12

Publication Date : 2025-06-19

Article Type : Research Paper

Abstract :Animal manure, agricultural wastes and sewage sludge are the most widely used organic wastes in biogas production. In our country, manure from animals such as cattle, sheep and chickens is an important source for biogas production. The mixing process in the digestion tank of the reactors used for biogas production significantly affects the biogas production efficiency. In recent years, it is known that the geometric structure of the digestion tank where the mixing process is carried out also affects this efficiency. In the mixing process, the most commonly used mixing type is mechanical mixing with the help of an propeller/impeller. Due to the high cost and time-consuming aspect of experimental studies, in recent years, the flow characteristics inside the digestion tank have been studied with the help of computational fluid dynamics software. In this context, velocity, turbulent eddy dissipation rate and turbulent kinetic energy distributions in the velocity range 50-175 rpm were investigated in a 60° slope digestion tank with a 6-flat-bladed impeller and the potential effects on biogas production were interpreted. The working fluid in the tank is considered by modeling dairy cattle manure as a non-Newtonian fluid. The results show that the velocity, turbulent kinetic energy and turbulent eddy dissipation rate distributions are generally more effective in the impeller region and at the impeller blade tips. In addition, as the impeller angular velocity increased from 50 rpm to 175 rpm, the amount of volume in the tank with velocity values higher than 0.1 m/s increased from 0.000323 m3 to 0.00262 m3.
Keywords : Biyogaz, çürütücü tankı, mekanik karıştırma, yenilenebilir enerji, HAD.

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