Torque and Horizontal Load on an Agitating Shaft in an Eccentric Mixer with a MAXBLEND Impeller in a Turbulent State

Abstract

In this study, the torque and horizontal load on an agitating shaft in an eccentric mixer with a MAXBLEND impeller at various impeller rotational speeds and eccentric conditions were measured in a turbulent state. The averages of both the torque and the horizontal load, and their standard deviations, corresponding to the amplitude of fluctuation, were calculated, and the causes of the fluctuation were investigated by FFT analysis. The average of torque was proportional to the square of the impeller rotational speed, and increased exponentially to 4.6 times the eccentric ratio. The standard deviation of the torque was smaller than the average torque. The increase in the average torque accompanying the increase in impeller rotational speed and eccentric length was summarized as a estimation equation for the average torque. In measuring of the horizontal load, the loads parallel to, and perpendicular to, the blade were measured independently. The average of these values was almost zero. The load perpendicular to the blade was one order larger than that parallel to the blade. The load perpendicular to the blade and the resultant load in parallel and perpendicular directions to the blade were proportional to the power of the impeller rotational speed and were an exponential function of the eccentric ratio. Based on this relation, equations for estimating the horizontal load were proposed.