GB700580A - Apparatus for controlling electric arc furnace electrodes - Google Patents

Abstract

700,580. Hydraulic machines; fluid-pressure servomotor control systems. MOORE, W. E. Sept. 4, 1951, No. 20884/51. [Classes 69 (2) and 135] Apparatus for raising and lowering an electrode 4, Fig. 1, in an electric arc furnace 2 comprises a hydraulic piston and cylinder motor 6 energized by a reversible pump 14 actuated by a motor 30 controlled by a device 31 in accordance with the voltage and/or current across the arc. The piston 7 of motor 6 is fixed and the cylinder 6a, Fig. 2, is guided by rollers 8 to move the electrode. Liquid is supplied to or withdrawn from the motor chamber 6b through a pipe 35 fixed to the top of the chamber to move with the cylinder and slidable in a bore 37 in the piston, the bore being connected through a pipe 11 and cooling device 12 to the pump. The position of the outlet of pipe 35 ensures that any air or gas in the chamber is removed by the pump on the down-stroke of the cylinder. A cooling chamber 38 in the cylinder has a water inlet 39 and an outlet 40. Oil is supplied from a reservoir 18 through a pipe 17 and check valve 16 and is returned through pipe 19, check valve 20 and pipe 21 which sprays the oil against the tank surface for cooling purposes. The space above the oil in the tank may be pressurized by a compressor 27 to an extent to counterbalance or slightly overbalance the weight of the electrode. Check valves 16, 20 may comprise a closure member 48, Fig. 3, urged to seat by a spring 55 adjustable by a screwed stem 58 whereby the valve may act as a check valve, a pressure regulating valve or a stop valve. Specifications 599,848 and 599,883 are referred to.