Draft Tube Length Influence on the Flow Inside Reactors with Intubated Impeller

The efficiency of a suspension homogenization/mixing reactor is evaluated by a uniform concentration of the suspension and low specific energy consumption (kW/m3). For a reactor with given geometry and volume, free or intubated impellers are used for the mixing of the suspension. In this work is studied the influence of the draft tube length. The streamlines corresponding to the flow of water are obtained through the numerical integration of Navier-Stokes equations. The increasing of the draft tube length modifies the flow, leading to the reduction of the number and intensity of the vortices inside the reactor (outside the draft tube). These vortices can lead to suspensions agglomeration, facilitating the sedimentation and thus increasing the energy consumption of the homogenization process.