MEANS FOR AUTOMATIC CONTROL OF BATCHING WHEN CASTING FROM A HEAT-RETAINING OF CASTING FURNACE OR LADLE (CRUCIBLE)

• US 3,834,587 A
• Filed: 11/13/1972
• Issued: 09/10/1974
• Est. Priority Date: 11/18/1971
• Status: Expired due to Term

• Current Assignee: Bergman Kjell, Fredrikson Bengt
• Original Assignee: Bergman Kjell, Fredrikson Bengt
• Inventors: Bengt, Fredrikson, Kjell, Bergman
• Primary Examiner(s): Reeves, Robert B.
• Assistant Examiner(s): Scherbel, David A.
• Application Number:
  US05/305,684
• Time in Patent Office: 666 Days
• Field of Search: 222/166,14,16,56,77,DIG.15,DIG.12 164/4,154,155
• US Class Current: 222/595
• CPC Class Codes: B22D 39/06 having means for controlling the amount of molten metal by controlling the pressure above the molten metal

Abstract

For the automatic control of batching when casting from a heatretaining furnace or ladle, an arrangement is provided for tapping the ladle in batches into a batching ladle. An arrangement is provided for weighing the batching ladle and the output signal of the weighing arrangement is fed to a deriving device which gives an output signal dependent on the melt flow. The output signal of the deriving device is fed to a comparison device along with a signal representing a desired value. A control device for the tapping of the furnace is combined with the output signal of the comparison device to terminate tapping when a predetermined quantity of melt has been tapped.

Claims

1. Means for automatic control of batching when casting from a crucible including a batching ladle, means for tapping the crucible in batches into the batching ladle, means for weighing the batching ladle, a deriving device, means for feeding the output signal of the batching ladle weighing means to the deriving device, means in the deriving device to transform the output signal of the batching ladle weighing means, which output signal depends upon the weight of batches of the tapped melt, into the derivative of the output signal of the batching ladle weighing means, the derivative of the output signal of the weighing means representing the rate of the melt flow out of the crucible, a reference device providing signals representing the desired value of melt flow rate out of the crucible, means responsive to the output signal of the batching ladle weighing means to change the output signal of the reference device, a comparison device, means to feed to the comparison device the signal from the reference device and the output signal from the deriving means, a control device for the tapping of the crucible, and means to feed to the control device output signals from the comparison device to control the tapping rate to maintain it at different values in response to differences in the weight of the batching ladle.

2. Means according to claim 1, in which the crucible is a furnace of submerged resistor type provided wiTh separate inlets and outlets and with an inflow for pressure medium at the hearth in order to control the tapping.

3. Means according to claim 2, in which a level measuring device is arranged at the outflow of the furnace and means responsive to the output signal of said level measuring device for controlling the pressure in the furnace.

4. Means according to claim 1, which includes means to measure the tare when the ladle is empty, a subtraction device, and means to feed the outputs of the tare measuring means to said subtraction device together with the output signal of the weighing means.