GB913269A - Improvements relating to furnace ladling apparatus - Google Patents

Abstract

913,269. Discharging molten metal. LINDBERG ENGINEERING CO. Aug. 8, 1960 [Sept. 8, 1959], No. 27469/60. Class 51 (2). [Also in Group XXII] Means for discharging molten metal from a furnace is adjustable between a condition in which it discharges the charge of molten metal to a point outside the furnace chamber and a condition in which it returns the charge to the furnace chamber and there is a stand-by control means which when actuated first adjusts the discharge means to its condition in which it returns the discharged metal to the furnace chamber, and then causes the discharge means to operate. A crucible 15 in the furnace chamber 11 is filled and discharged by alternately subjecting it to vacuum and discharging pressure by a pump 19. The melt is drawn by vacuum through the inlet passage 16 into the crucible to a level slightly above the inlet opening 17, atmospheric or a relatively low intermediate pressure being then applied to the crucible to force the level therein to the inlet opening level, and the level in the passage 16 to below this level. A high pressure is then applied to the crucible for discharging through the pipe 18. A launder 25 is movable between the positions 25, 25a by a cylinder 32, in the latter position the launder directing the discharge back to the furnace changer. The electrical control system comprises timers such that the apparatus will automatically shut down if the interval between discharging cycles exceeds a predetermined period which would tend to produce freezing of the melt in the crucible or discharge tube above the level of the metal in the furnace chamber. The launder moves to the position 25a and the crucible discharges into the furnace.