| 摘要 |
1,166,789. Electromagnetic mixing apparatus. AJAX MAGNETHERMIC CORP. 3 July, 1968 [15 Feb., 1968], No. 31749/68. Heading B1C. [Also in Divisions H2 and H5] A coreless electric induction furnace 10 has a heating and stirring coil of two or more sections as at A, B, the section A being connected to a single phase power supply 11 and section B to a capacitance 14, 14' and not to the power supply; the capacitance is turnable in resonance with the power supply frequency so that section B has a 90‹ phase lag, producing a travelling magnetic field causing unidirectional flow of the outer parts of the melt (as shown, upward) with a return flow in the centre. Capacitance 12, 12' is provided to improve the power factor. The arrangement may be converted to one more suitable for melting by closing switch 17 when sections A, B are connected in parallel to the power supply. The capacitors 12, 12', 14, 14' may be adjustable manually or automatically; taps may be provided on the coil or a transformer interposed between coil and capacitors. In a modification (Fig. 3, not shown) the coil has four sections A, B, C, D, the power supply being connected to A and C, and the capacitance to B and D in series or parallel. There is then a phase lag of 90‹ between each successive coil section. In a further modification (Fig. 4, not shown) the direction of flow of the melt may be reversed by providing switches (30, 40) to connect sections A, C to the capacitance and sections B, D to the power supply. For melting the sections are connected in two groups A, C and B, D in parallel to the power supply, the sections in each group being in series and switches (31, 32) being provided to reverse the connections to C, D so that all four sections are in phase. The invention may be applied to the pumping of molten metal in a pipe-line, the metal in the centre of the pipe being carried along with the flow at the periphery. |
