James B. Beal, Jr. and Albert W. Jache Texas A & M College
College Station
A Simple Agitation Device for Several Closed Containers
W e have found it necessary to stir the contents of several closed containers immersed in a constant temperature bath. Usually the stirring has had to continue for a long time. A simple device employing Teflon coated magnetic stirring bars and an alternating field of magnetic flux has been made. The system was designed to accommodate six 250-ml polyethylene bottles, each containing the materials to be agitated and a Teflon coated magnetic stirring bar. The coils and cover used were 12-henry chokes (120 v ac) that had their mounting frames removed. These chokes had been dipped in G.E. Glyptal Enamel several
times for waterproofing. They were mounted on a sheet of Lncite in two rows of three, with the rows facing each other. The coils were wired in parallel to cause the direction of flow in one row to be opposite to the other.
Figure 2.
Figure 1.
Arrangement of choke coils in rubmerged box
Schematic diogrorn of magnetic
agitator.
The dc pourer supply for the coils consisted of a powerstat and a selenium rectifier. The direct current direction alternator consisted of a spring biased double pole double throw 120-v ac relay and a 60-watt flasher and 60-watt lamp, all in series. The use of the particular components was la~gelydictated by local availability. A second agitator has been built in which the chokes are mounted upward in a copper box which can be submerged (Fig. 1). Bottles containing magnetic bars may be agitated on the top surface of this box. The schematic wiring diagram is shown in Figure 2.
Volume
37, Number 12, December 1960
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615
