Flow fields and torque load characteristics in twin-blade planetary kneaders: A scale-up study

It is essential to investigate the complex flow characteristics and torque load characteristics within twin-blade planetary kneaders. In this work, computational fluid dynamics (CFD) is employed to investigate the key process variables and scale-up effects. Firstly, the flow characteristics of a 1 L twin-blade planetary kneader is investigated. The flow field is primarily controlled by blades’ self-rotation. The torque acting on the hollow blade is 2–6 times higher than that on the solid blade. Rotational speed ratios have minimal effect on torque values and periods. Further, the kneader is scaled up to 5 L and 25 L using the criterion of constant blade-tip speed. The scaled kneaders achieve the intended performance and the chosen scaling criterion is appropriate. The total power consumption is mainly driven by the rotational component of the hollow blade, and contributions of each motion component to the total power are consistent across scales. This work provides valuable references for optimizing kneading parameters, scaling design, and process enhancement.