Electromagnetic stirrer operating in double axis

Abstract

In this paper, a new rotating magnetic stirrer system that is controlled by a programmable-integrated-circuit (PIC) microcontroller and can stir in double axis is developed. In contrast to making a stirring action only at one point, as in the case of traditional electromagnetic stirrers, the system that is developed can rotate at two separate axes. One of the rotations is around the axis of the magnetic stir bar itself, and the other is over a circle defined by a rotating magnetic field. That is, the stirrer makes two rotational motions. This is the main contribution of this paper. The magnetic stirrer system is designed as a three-phase system, and a sinusoidal ramp signal is applied to the phases as the supply voltage. During the design stage, the mathematical model of the system was obtained, and the parameters affecting the design were determined. Based on these parameters, a parameter set was established. This parameter set can be used for subsequent design studies of the system. A PIC-based control circuit is used to control the frequency of the supply voltage. The structure of the double-rotating electromagnetic stirring system is explained. The physical conditions affecting the double-axis rotational motion of the magnetic stir bar are discussed in detail. It was observed that a more homogeneous stirring process could be achieved with this kind of double-axis rotation.