Abstract
The 2-pole-double-sided-flat-type electromagnetic pump is a most practical type of automatic pouring machine for casting. In this paper, the effect of the width of the stator core and channel on the output and the starting characteristics of the pump have been examined both theoretically and experimentally. In the experiment, mercury and molten aluminum were used. The results were as follows:
(1) When the width of the channel was larger than that of the stator core, the output was larger compared to the pump with the same width, because of the magnetic flux leakage and finite width effect of the channel.
(2) Smaller channel width decreased the output of the pump considerably.
(3) The output of the pump could be calculated theoretically using the experimental data of the magnetic flux.
(4) When the time constant of the pump electric circuit or fluid inertia was large, it took considerable time for the flow velocity to reach the appointed value. This should be noted in the design of high speed automatic pouring machines.
(5) The starting characteristics of the pump could be caluculated theoretically using the experimental data of the time constant.
(6) A 2-pole electromagnetic pump for molten aluminum was produced by way of trial. When the magnetizing current was 100A and pumping head was 100mm, the pouring capacity was about 18 kg/min. The net efficiency was 0.014% and power factor was about 0.2 to 0.5.
(7) Velocity of the molten aluminum were measured successfully by the electromagnetic flow meter.
(8) Flow resistance was very large contrary to expectations. This should be considered in the design of the pump.
(9) When molten aluminum is pumped out through a channel of about 100×6mm2 of cross-sectional area, a heating device to prevent solidification is necessary.
(10) Great care is needed to prevent thermal crack of the channel connection.
