Abstract: The invention relates to a remelting plant comprising a furnace chamber (50), which can be positioned over a crucible (60) of a melting station, an electrode rod (48), which by way of a lead-through (52) can be inserted or is inserted in the furnace chamber (50), in order to contact a consumable electrode (58), and a guide column (30), on which an electrode rod carriage (40) that is fixed-ly connected to the electrode rod (48) is guided in an axially movable manner, in order to move the electrode rod (48) in relation to the furnace chamber (50), and on which a chamber carriage (38), which is connected or can be connected to the furnace chamber (50), is guided in an axially movable manner, in order to move the furnace chamber (50).

Abstract: Melting furnace (1), in particular for the production of metal alloys by melting alloying constituents, with a melting crucible (10), a cylindrical electrode rod (40) with a consumable electrode (41) attached thereto and a power supply (50) that is configured to supply the electrode (41) with power via the electrode rod (40), wherein the electrode rod (40) can be rotated about its own axis and moved along its own axis during the melting process.

Abstract: An apparatus for and method of controlling a remelting furnace comprising adjusting current supplied to an electrode based upon a predetermined pool power reference value and adjusting the electrode drive speed based upon the predetermined pool power reference value.

Abstract: An apparatus and method for controlling an electroslag remelting furnace comprising adjusting electrode drive speed by an amount proportional to a difference between a metric of electrode immersion and a set point, monitoring impedance or voltage, and calculating the metric of electrode immersion depth based upon a predetermined characterization of electrode immersion depth as a function of impedance or voltage.

Abstract: A method of and apparatus for controlling an electroslag remelting furnace by driving the electrode at a nominal speed based upon melting rate and geometry while making minor proportional adjustments based on a measured metric of the electrode immersion depth. Electrode drive speed is increased if a measured metric of electrode immersion depth differs from a set point by a predetermined amount, indicating that the tip is too close to the surface of a slag pool. Impedance spikes are monitored to adjust the set point for the metric of electrode immersion depth based upon one or more properties of the impedance spikes.

Abstract: A method of and apparatus for controlling an electroslag remelting furnace by driving the electrode at a nominal speed based upon melting rate and geometry while making minor proportional adjustments based on a measured metric of the electrode immersion depth. Electrode drive speed is increased if a measured metric of electrode immersion depth differs from a set point by a predetermined amount, indicating that the tip is too close to the surface of a slag pool. Impedance spikes are monitored to adjust the set point for the metric of electrode immersion depth based upon one or more properties of the impedance spikes.

Abstract: The present invention relates to a method for determination of the electrode tip position for consumable electrodes in electric smelting furnaces, which electrodes being submerged in the furnace charge. The voltage between two geometrically displaced points on the outside of the steel wall of the furnace pot is measured during operation of the furnace, points being situated as close as possible to the electrode for which the electrode tip position is to be determined, and as far away as possible from the other electrodes in the furnace. The electrode current for the electrode for which the electrode tip position is to be determined, is recorded at the same time as the voltage between the two points are measured, whereafter the difference between measured voltage between the two points and measured electrode current is calculated, and where the absolute value of difference increases when the electrode tip position increases and decreases when the absolute value of difference decreases.

Abstract: An apparatus and method of controlling a remelting process by providing measured process variable values to a process controller; estimating process variable values using a process model of a remelting process; and outputting estimated process variable values from the process controller. Feedback and feedforward control devices receive the estimated process variable values and adjust inputs to the remelting process. Electrode weight, electrode mass, electrode gap, process current, process voltage, electrode position, electrode temperature, electrode thermal boundary layer thickness, electrode velocity, electrode acceleration, slag temperature, melting efficiency, cooling water temperature, cooling water flow rate, crucible temperature profile, slag skin temperature, and/or drip short events are employed, as are parameters representing physical constraints of electroslag remelting or vacuum arc remelting, as applicable.

Abstract: A method and apparatus for controlling vacuum arc remelting (VAR) furnaces by estimation of electrode gap based on a plurality of secondary estimates derived from furnace outputs. The estimation is preferably performed by Kalman filter. Adaptive gain techniques may be employed, as well as detection of process anomalies such as glows.

Abstract: An apparatus and method for controlling an electroslag remelting furnace, imposing a periodic fluctuation on electrode drive speed and thereby generating a predictable voltage swing signal. The fluctuation is preferably done by imposition of a sine, square, or sawtooth wave on the drive dc offset signal.

Abstract: A process and a device for regulating the position of the tip of an electrode immersed in an electric furnace heated by electric arc or resistance heating. To precisely measure the position of the electrode tip and to position it in operation, a series of gas containers are introduced into the electrode in succession at certain intervals, with each gas container being given a serial number (n.sub.i). The position of the electrode tip is determined by computer from the data of the last gas container with the serial number (n.sub.j) and the current number of the melted-open gas container, determined by gas analysis, using the gas that rises in the furnace through the melting process. Control technology is then applied to the drive of the electrode bearing device.

Abstract: A system for controlling electrode gap in an electro-slag remelt furnace has a constant regulated voltage and an eletrode which is fed into the slag pool at a constant rate. The impedance of the circuit through the slag pool is directly proportional to the gap distance. Because of the constant voltage, the system current changes are inversely proportional to changes in gap. This negative feedback causes the gap to remain stable.

Abstract: An electric arc furnace includes at least one electrode projecting into a furnace vessel for containing a charge to be heated and electrode support structure for moving the electrode in a direction along a path towards and away from the charge. An improvement to the electric arc furnace comprises a sensor for detecting the position of the electrode support structure from an initial position. A processor calculates one of a support structure travel distance from the initial position and a rate of electrode consumption. An alarm signal is generated in response to at least one of the travel distance and the rate of electrode consumption being at least equal to a respective predetermined threshold travel distance or a predetermined threshold rate of electrode consumption, either of which is indicative of an excess electrode consumption condition for a given heat.

Abstract: A remelting furnace has a crucible (2) and a raisable pot (3) placed thereon. An electrode rod (6) leads into the pot (3) through a stuffing box (8) borne by a lower platform (9). The lower platform (9) is carried by rods (12, 13) which are fastened each at its upper end to a weighing platform (14). The connection of the lower platform (9) to the particular rod (12, 13) is performed in each case through a releasable clutch (10,11 ). Consequently, a lifter (17) can lift the pot (3) such that it shifts upwardly with the bottom platform (9) relative to the rods (12, 13).

Abstract: According to this process and this device:a signal representing the derivative of the intensity of the current in the arc is sensed,the sensed signal is amplified,the amplified signal is directed simultaneously into two band pass filters (6, 7) respectively having a high frequency broad band (6) and having a narrow band centered on a low fundamental frequency (7),the signals emanating from the filters (6, 7) are transmitted to effective value extractors (8, 9),by means of a divider module (11) an energy signal is formulated, which is proportional to the ratio of the effective value of the signal emanating from the broad band filter (6) and the effective value of the signal emanating from the narrow band filter (7),and the proportional energy signal obtained is displayed on a scale (12), where it is expressed as a percentage, this percentage being indicative of the behaviour of the arc, signifying the formulation phase.

Abstract: A compensation device for the influence of the weight of a power feed line on a weight measurement device determining the weight of an electrode and/or the melting rate in an electro-slag remelting process, in a vacuum arc furnace or the like. When an x-y device is adjusted, a weight jump occurs due to the forces of the power cable or the forces of the bellows, which has a disturbing effect on the rate definition. This weight jump can be prevented by means of mechanical devices, or can be made so small that it no longer constitutes a disturbance. However, the expenditure for this is disproportionately high. The invention is more cost efficient, since hardware or software means suffice. The weight function G=f(t) is extrapolated and compared with the actually measured weight G'=f(t). The magnitude of the difference between the two is stored and later added as a correction value.

Abstract: Control system for electroslag remelting having a block for recording arc discharges, the input of which is connected to the current-carrying bus bar of a crystallization mold, while its output is connected to a block for switching over the rate of electrode feed, to the second input of which there is connected the output of a presetting block, and the output of the block for switching over the rate of feed of the electrode is connected via a regulator to an actuating mechanism. The current-carrying bus bar is connected to a block for recording the rectifier valve effect, the output of which is connected via a block for operation switch-over to a third input of the block for switching-over the rate of electrode feed.

Abstract: A method of and an apparatus for controlling an electroslag remelting furnace in which the passage of the electrode through limiting slag levels defining a no-arc zone of operation results in arcing which produces an electromagnetic emission which is detected by a separating filter and is used to control a drive for the electrode.