Control system for electrical furnaces

Claim 2

A control system for electrical furnaces comprising: 1. computer means operative to receive a plurality of input signals indicative of metallurgical process parameters, and further operative to process said plurality of input signals and to generate a plurality of output signals for controlling the quantity and mixture of charge fed to the associated furnace, for controlling the position of the electrodes in the associated furnace, and for controlling the power consumed by the associated furnace; and 2. charge feed means operative in response to at least one of said plurality of output signals to feed and control the quantity and mixture of charge to the associated furnace.

Claim 3

The control system according to claim 1 wherein said charge feed means comprises at least one hopper having at least one section.

Claim 4

The control system according to claim 1 wherein said charge feed means is linked to said at least one hopper by at least one conveyor means which is controlled by said computer means.

Claim 5

The control system according to claim 1 wherein said control system further comprises charge weighing means, and said computer means is operative to control the amounts of charge components fed to the associated furnace by said charge feed means in response to at least one of said plurality of output signals.

Claim 6

The control system according to claim 4 wherein said computer means comprises a furnace computer means and a weighing computer means.

Claim 7

The control system according to claim 5 wherein said weighing computer means is operative to correct the nominal set points of a desired feed mix receipe.

Claim 8

The control system according to claim 5 wherein said weighing computer means is operative to introduce a time delay between the discharge of each of a plurality of hoppers to ensure a homogeneous mixing of the charge components.

Claim 9

The control system according to claim 1 further comprising readout means operative to provide visual indications of selected input signals and of variables calculated by said computer means.

Claim 10

The control system according to claim 8 wherein said computer means is operative to perform in an open loop mode in which control actions are carried out manually by a human operator in response to said visual indications of said selected input signals to said computer means and of said variables calculated by said computer means.

Claim 11

The control system according to claim 1 further comprising input means operative upon manipulation by a human operator to transmit messages to said computer means.

Claim 12

A control system for electrical furnaces comprising: 1. computer means operative to receive a plurality of input signals indicative of metallurgical process parameters, and further operative to process said plurality of input signals and to generate a plurality of output signals for controlling the charge fed to the associated furnace, for controlling the position of the electrodes in the associated furnace, and for controlling the power consumed by the associated furnace; 2. charge feed means operative in response to at least one of said plurality of output signals to feed quantities of corrective and additive charge to the associated furnace; 3. carbon balance control means operative to control carbon content in the charge in the associated furnace in a closed loop mode; 4. current control means operative to control the currents through the electrodes of the associated furnace in a closed loop mode; and 5. electrode control means operative to control the positions of the electrodes in the associated furnace in a closed loop mode.

Claim 13

A control system for electrical furnaces comprising: 1. computer means operative to receive a plurality of input signals indicative of metallurgical process parameters, and further operative to process said plurality of input signals and to generate a plurality of output signals for controlling the charge fed to the associated furnace, for controlling the position of the electrodes in the associated furnace, and for controlling the power consumed by the associated furnace; 2. charge feed means operative in response to at least one of said plurality of output signals to feed quantities of corrective and additive charge to the associated furnace; 3. carbon balance control means operative to control carbon content in the charge in the associated furnace in a closed loop mode; 4. current control means operative to control the currents through the electrodes of the associated furnace in a closed loop mode; and 5. electrode control means operative to control the positions of the electrodes in the associated furnace in a closed loop mode.

Claim 14

The control system according to claim 11 wherein said carbon balance control means is operative in response to variations in charge resistance to adjust the concentration of carbon in the charge in the associated furnace.

Claim 15

The control system according to claim 11 wherein said current control means comprises electrode current regulators operated on constant impedance, the impedance set points of the regulators being adjusted by said computer means to obtain symmetrical electrical loading at the optimum current value.

Claim 16

The control system according to claim 11 wherein said electrode control means is operative to effect a predetermined amount of slippage of each electrode at optimum time intervals determined by said computer means.

Claim 17

The control system according to claim 2 wherein said at least one hopper comprises a reservoir section, a transit section, and a discharge tube, the transit section having a mouth at its discharge end which is of approximately the same size and area as the mouth of the receiving end of the discharge tube, the transit section being disposed with respect to the discharge tube to permit substantially straight flow of material from the discharge end of the transit section to the receiving end of the discharge tube, and the discharge end of the reservoir section being disposed to feed material to the discharge tube at an angle to the straight flow of material from the discharge end of the transit section to the receiving end of the discharge tube, whereby material fed to the transit section will pass to the discharge tube substantially in its entirety before any appreciable quantity of material passes from the reservoir section to the discharge tube.

Claim 18

The control system according to claim 15 wherein said reservoir section and said transit section are in the same hopper and are separated by a common partition.