Abstract
Recently, the induction-type electromagnetic pumps for automatic pouring have been introduced into some foundries, but the conduction-type electromagnetic pumps (henceforth described as c. e. pumps) are not used as yet.
In this study, by assuming that the c. e. pump is used for high speed automatic pouring, the pump-out characteristics (i. e., the characteristics of starting and emergency shut down) was examined by using mercury and the data obtained was compared with the theoretically analyzed one. Then, a c. e. pump for molten aluminum was produced by way of trial and its pump-out characteristics were examined.
The results are the following.
(1) The output of the pump is independent of the velocity of the molten metal within the limits of this experiment. (Pump current<100A, Velocity<2m/sec)
(2) When molten metal is pumped out from a reserve furnace, the velocity (consequently, the flow rate) decreases with decrease of the molten metal surface in the furnace.
(3) The pump-out velocity is greatly affected by the flow resistance of the channel.
(4) When the size of the channel is large, it takes considerable time for the molten metal to reach the appointed velocity because of the fluid inertia.
(5) These phenomena prolong the pouring time and therefore decrease the production speed. The flow rate/time relation can be calculated theoretically.
(6) When the pump-out head and velocity head are large, a sudden shut down of the pump causes free vibration of the molten metal in the channel. This may be dangerous for operation.
(7) The trial production of the c. e. pump for molten aluminum was successful. The electrode of the pump was made of carbon and the channel was made of high alumina.
(8) These results show the possibility of using the c. e. pump in the foundries for commercial production.
