Patent Description:
An electric arc furnace heats a charge of steel scrap material by means of an electric arc. The charged material is melted by direct exposure to the electric arc and subsequent passing of the electric current therethrough. An electric arc furnace generally includes a large vessel, covered with a retractable roof. The roof includes holes that allow one (in a DC furnace) or more commonly three (in an AC furnace) graphite electrode columns to enter the furnace. A movable electrode support structure holds and moves the electrode columns to maintain proximity to the scrap material. Power for the electrode columns is provided by a transformer, typically located near the furnace. The electrode columns each include a plurality of individual electrodes that are secured together with threaded connections at each end. The electrodes are slowly consumed as part of the steel making process and thus, new electrodes must be added to each column periodically.

During the melting cycle, referred to as a "heat", a power regulating system attempts to maintain approximately constant current, power, impedance, admittance, resistance or some combination of these inputs during the melting of the charge. The regulator therefore seeks to control the distance between the electrode tip and the burden (solid charge material or molten metal) given the adopted regulation philosophy. This is made more difficult when scrap moves under the electrodes as it melts. Input is regulated, in part, by employing an electrode positioning system which automatically raises and lowers the electrode columns. In most cases, positioning systems may employ hydraulic cylinders to provide the moving force. Once relatively steady state conditions are reached in the furnace, (i.e. the scrap is substantially melted) another bucket of scrap may be charged into the furnace and melted down. After the first or optional second charge is completely melted, various other operations take place such as, refining, monitoring chemical compositions, and finally superheating the melt in preparation for tapping.

The graphite electrodes' chemical composition can be varied somewhat by the manufacturer to optimize performance characteristics. Determining electrode performance in the EAF requires knowledge of which specific electrodes are being used in each heat. It is desirable to obtain this information in an accurate and automated manner.

<CIT> relates to a system for recording information relating to the condition of electrodes in an electric arc furnace using a digital camera in a consistent position relative to a photographing station.

According to a first aspect of the invention, provided herein is a graphite electrode (<NUM>) comprising; an electrode body (<NUM>) formed of graphite having oppositely disposed first (<NUM>) and second (<NUM>) ends; and a threaded connector (<NUM>, <NUM>) disposed at at least one end; wherein the electrode (<NUM>) further includes a tag (<NUM>) attached to the body (<NUM>), wherein the tag (<NUM>) creates a non-line-of-sight signal representing an electrode identifier, wherein the threaded connector (<NUM>, <NUM>) is at least one of a pin and a socket and wherein the tag (<NUM>) is attached to at least one of the pin and the socket.

In embodiments, the tag (<NUM>) may be a Radio Frequency identification, RFID, tag.

In embodiments, the tag (<NUM>) may be a Radio Frequency identification, RFID, tag, and the electrode (<NUM>) may further comprise a first RFID tag and a second RFID tag, wherein the first RFID tag may be attached at or adjacent to the first end (<NUM>) and the second RFID tag may be attached at or adjacent to the second end (<NUM>).

In embodiments, the electrode identifier may include one or more of an identifier identifying a location at which the electrode (<NUM>) was machined, an identifier identifying a line on which the electrode (<NUM>) was machined, a weight of the electrode (<NUM>), a date the electrode (<NUM>) was machined, a sequential number identifying a specific electrode (<NUM>), batch identification information identifying a batch from which the electrode (<NUM>) was formed, or an electric arc furnace, EAF, owner-specific number.

In embodiments, the tag may be located at an axial end of the one of the pin or socket.

According to a second aspect of the invention, provided herein is method of monitoring an electrode discussed above comprising: capturing signals from radio frequency identification, RFID, tags (<NUM>) using an RFID tag reader (<NUM>), wherein the RFID tags (<NUM>) are attached to graphite electrodes (<NUM>), and the method further includes converting the signals into electrode identifiers identifying the graphite electrodes (<NUM>) and transmitting the electrode identifiers to a monitor (<NUM>), wherein the method further comprises: receiving a plurality of electrode identifiers from the RFID tag reader (<NUM>); associating the plurality of electrode identifiers with Electric Arc Furnace, EAF, data corresponding to the plurality of electrode identifiers; and storing the associations in memory (<NUM>).

In embodiments, the method may further comprise receiving an electrode identifier from a radio frequency identification, RFID, tag reader (<NUM>) configured to interrogate RFID tags (<NUM>) at a location, wherein the RFID tags (<NUM>) may be attached to electrodes (<NUM>); receiving EAF data collected from an EAF (<NUM>); associating the EAF data with the electrode identifier; and storing the association in a monitor memory (<NUM>).

In embodiments, the method may further comprise generating past EAF operating parameters; associating the past EAF operating parameters with specific electrodes (<NUM>) using the electrode identifiers; generating current EAF operating parameters; associating the current EAF operating parameters with specific electrodes (<NUM>) using the electrode identifiers; and displaying the associations on a furnace monitoring viewer system (<NUM>).

In embodiments, the method may further comprise associating the electrode identifier with an electrode column (<NUM>, <NUM>, <NUM>).

In embodiments, the method may further comprise capturing a signal from a tag (<NUM>) attached to an electrode (<NUM>) using an RFID tag reader (<NUM>); converting the signal into an electrode identifier identifying the electrode (<NUM>); transmitting the electrode identifier to a monitor (<NUM>); and determining an electrode (<NUM>) as being in a location using the electrode identifier.

In embodiments, the method may further comprise determining the electrode (<NUM>) as being in the vicinity of the EAF (<NUM>) using the electrode identifier.

In embodiments, the method may further comprise repeating the receiving the plurality of electrode identifiers, the associating the plurality of electrode identifiers with EAF data and the storing the associations in memory (<NUM>); determining a missing electrode identifier to be an electrode identifier that is not in the set of stored electrode identifiers; identifying the missing electrode identifier as an added electrode (<NUM>) added to an electrode column (<NUM>, <NUM>, <NUM>), the electrode column (<NUM>, <NUM>, <NUM>) having a plurality of electrodes (<NUM>) connected together; and associating the added electrode (<NUM>) with the electrode column (<NUM>, <NUM>, <NUM>).

In embodiments, the step of determining may further comprise determining the missing electrode identifier to be an electrode identifier which is in the set of stored electrode identifiers during a first time period and which is not in the set of stored electrode identifiers during a second time period, the second time period occurring after the first time period.

According to a third aspect of the invention, provided herein is a system (<NUM>) for identifying graphite electrodes (<NUM>) discussed above used in an electric arc furnace, EAF, (<NUM>), the system comprising: at least one electrode as discussed above; at least one antenna (<NUM>) disposed in a vicinity of the EAF (<NUM>); a tag reader (<NUM>) operatively connected to the at least one antenna (<NUM>), the tag reader (<NUM>) including a processor (<NUM>) configured for receiving signals from the at least one antenna (<NUM>) and converting the signals to electrode identifiers each identifying a specific graphite electrode (<NUM>), and memory (<NUM>) for storing the electrode identifiers; and a monitor (<NUM>) operatively connected to the tag reader (<NUM>), the monitor (<NUM>) including a processor (<NUM>) and memory (<NUM>), the processor (<NUM>) configured for receiving the electrode identifiers, associating the electrode identifiers with EAF data corresponding to specific electrodes and storing the association in the monitor memory (<NUM>).

The structure and preferred embodiments of the invention can best be understood by reference to the accompanying drawings, in which:.

Graphite electrodes are a necessary consumable in an electric arc furnace and are the only known material suitable to withstand the extremely harsh operating environment of the electric furnace steelmaking operation. Accordingly, steel manufacturers are highly cognizant of the cost and performance of the graphite electrodes being consumed in the furnace. The systems and methods disclosed herein for monitoring electrodes used in an electric arc furnace can be used to monitor and improve the performance of graphite electrodes.

Referring now to <FIG>, a system for monitoring electrodes used in an electric arc furnace (EAF) constructed in accordance with the present invention is shown generally by reference numeral <NUM>. The electrode monitoring system <NUM> includes a monitor <NUM>. The monitor <NUM> can be an electrode monitor for collecting and processing data related to electrode identification and monitoring. In other examples, the monitor <NUM> can be a furnace monitor <NUM> for collecting and processing operational data for an EAF shown generally at <NUM>. The EAF <NUM> can be an AC furnace, of a <NUM> phase design having an electrode column for each phase, or a DC furnace consisting of one or two electrode columns. A <NUM> phase EAF AC furnace is described herein by way of example. The EAF <NUM> uses electrodes, referred to generally at <NUM>, to melt metals and other ingredients to form steel. The electrodes <NUM> are joined together end-to-end to form electrode columns <NUM>, <NUM>, <NUM>, with each column powered by a separate electrical phase (in <NUM> phase AC furnaces). DC furnaces employ a single column (i.e. cathode), or two columns (i.e. anode and cathode). The heat needed to melt metals is generated by passing current through the one or more of the electrode columns <NUM>, <NUM>, <NUM> and forming an arc between the electrode column(s) and the metal in the furnace. Electrical currents in excess of <NUM>,<NUM> amperes are often used. The resulting high temperature melts the metals and other ingredients in an heating operation known as a "heat", further details of which are provided below.

The furnace monitor <NUM> is a computer control device, such as for example a modular controller, configured to receive a wide range of data regarding of the operation of the furnace <NUM>. The furnace monitor <NUM> is typically a local device, disposed onsite at the site of the EAF <NUM>. The electrode monitor and/or furnace monitor <NUM> includes a processor <NUM>, memory <NUM> and an input/output module <NUM> which are used for monitoring the electrodes <NUM> used in the furnace <NUM>, as described in further detail below.

An electrical meter <NUM> is operatively connected to the furnace monitor <NUM>, such as by an Ethernet connection <NUM>, for collecting electrical data pertaining to the furnace <NUM>. The electrical meter <NUM> can be a power meter, an ion meter, or other furnace monitoring device. The furnace monitor <NUM> collects the furnace electrical data from the electrical meter <NUM> on a periodic basis. The collected data includes voltage and current measurements generated from the current and voltage transformers connected to each phase of the primary electrical circuit. The furnace electrical data is an example of EAF data which is associated with specific electrodes using electrode identifiers as described in further detail below.

The system <NUM> further includes one or more programmable logic controllers (PLCs), only one of which is shown for simplicity at <NUM>. The one or more PLCs <NUM> are operatively connected to the furnace monitor <NUM> via the EAF owner's existing PLC network <NUM>, examples of which can include an Ethernet connection and/or a serial connection such as for example an RS242, RS422 or RS485 connection. The one or more PLCs <NUM> provide process information about each "heat," to the furnace monitor <NUM>. The process data for each heat includes times, oxygen and natural gas consumption, process weights, temperatures and end-of-heat signals. The process data is another example of EAF data which is associated with electrode identifiers as described in further detail below.

A furnace monitor viewing system <NUM> is connected to the furnace monitor <NUM> via a wired or wireless local connection <NUM> for displaying the EAF data to users located onsite, i.e. at the EAF facility. The furnace monitor viewer system <NUM> can display the EAF data in real time during the operation of the EAF to assist furnace operators during furnace operation.

In at least one example, the system <NUM> can also include a remote server <NUM> located at a different location than the onsite furnace monitor <NUM> and connected to the furnace monitor via the Internet <NUM>. The remote server <NUM> includes a database <NUM> for storing the furnace data and processed data received from the furnace monitor <NUM>. The remote server <NUM> also includes a processor <NUM> configured to further process the EAF data in association with electrode identifiers identifying specific electrodes to allow a user to view current and past operating parameters of the electric arc furnace <NUM> including operating trends, historical trends, statistical tables and graphical representations to better assist the viewer in evaluating the operation of the furnace <NUM> at it relates to specific electrodes, as described in further detail below. The remote server can include an Internet portal <NUM> for allowing authorized users to access the data described herein via the Internet. The remote server <NUM> can be a central server connected furnace monitors at several different EAF facilities. Alternatively, the remote server <NUM> can be dedicated to a single EAF facility.

In at least one example, the system <NUM> can also include a remote viewer <NUM> operatively connected to the furnace monitor <NUM>, the remote server <NUM>, or both via an internet connection <NUM>. The remote viewer <NUM> enables offsite technicians to view the furnace data and the current and past operating parameters described above.

The system <NUM> also includes an electrode detection and identification device <NUM> which detects an electrode and provides an electrode identifier to the furnace monitor. In at least one example, the device <NUM> includes a Radio Frequency Identification (RFID) tag reader <NUM>, also known as an interrogator, or reader, connected to one or more antennas <NUM>. The antennas <NUM> are disposed at a location <NUM>, such as the vicinity of the EAF furnace <NUM>, for capturing signals from RFID tags, referred to generally at <NUM>, which are attached to electrodes <NUM> that are located in that vicinity <NUM>.

Referring now to <FIG>, an example graphite electrode discussed herein is shown generally at <NUM>. The graphite electrode <NUM> includes an electrode body <NUM> formed of graphite. The body <NUM> is generally cylindrical having oppositely disposed ends <NUM> and <NUM> which include threaded connectors. The threaded connectors can include a threaded socket <NUM> formed in one of the ends, <NUM>, <NUM> and a threaded pin <NUM> formed at the other of the ends. In one example the threaded pin <NUM> is formed integrally with the body <NUM>, such as by machining. The pin <NUM> includes a truncated conical threaded portion <NUM> extending from the body end <NUM> and terminating in an end face <NUM>. In another example, the pin <NUM>' includes oppositely disposed truncated conical threaded portions <NUM>' each terminating in oppositely disposed end faces <NUM>. In this example the pin <NUM>' is threaded into a socket <NUM> of an electrode which has a socket at each end <NUM> and <NUM> to form a pin disposed at one of the ends <NUM>, <NUM>.

The threaded pin <NUM>, <NUM>' and threaded socket <NUM> are of matching size and shape so that the threaded pin <NUM> of one electrode 11a can be received in the threaded socket <NUM> of another electrode 11b to join the electrodes together at a joint <NUM> to form an electrode column shown generally at <NUM> in <FIG>. As discussed above, when in use in the EAF, a separate electrode column <NUM> is used for each phase of a multi-phase furnace. Thus, for example, the <NUM> phase AC EAF <NUM> shown in <FIG> utilizes <NUM> electrode columns <NUM>, <NUM>, <NUM>, each corresponding to a different electrical phase of the <NUM> phase EAF.

The electrode <NUM> includes at least one tag <NUM> attached to the body, wherein the tag creates a non-line-of-sight signal representing an electrode identifier. The tag <NUM> can be an RFID tag. The RFID tag <NUM> can be a passive tag having a non-powered signal generator configured to transmit a signal to the antenna <NUM> described above. Alternatively, the RFID tag <NUM> can be an active tag having a powered signal generator configured to transmit a signal to the antenna <NUM>. In each instance, the signal corresponds to an electrode identifier. The electrode identifier uniquely identifies a single, specific electrode. The electrode identifier can include electrode data corresponding to the specific electrode which it identifies. Examples of this electrode data can include some or all of, but is not limited to, an identifier identifying the location of the plant at which the electrode was machined, an identifier identifying the line on which the electrode was machined, a weight of the electrode, a date the electrode was machined, a sequential number for identifying a specific electrode within a sequence of numbers identifying a set of electrodes. An electrode identifier including this combination of electrode data can be referred to as a Base of Socket identifier. The electrode identifier can also include batch identification information identifying the batch from which the graphite electrode was formed. The electrode identifier can include an EAF owner-specific electrode identifier, also known as a stencil number, for identifying the specific electrode using criteria provided by the EAF owner.

The electrode <NUM> can include one RFID tag <NUM> attached to the body <NUM>. Examples of this arrangement include the one tag attached to the pin <NUM>, or to a different location at the end <NUM>, or to the socket <NUM> or to a different location at the end <NUM>, or to body <NUM> disposed between the ends <NUM>, <NUM>. The electrode <NUM> can include two RFID tags <NUM>. In one example the two tags <NUM> are configured to transmit the same signal to the antenna <NUM> corresponding to the same electrode identifier. In another example, the two tags <NUM>', <NUM>" are configured to transmit the different signals to the antenna <NUM> corresponding to the same electrode identifier. The RFID tags will be referred to generally as RFID tag <NUM>, or tag <NUM>. A collection of RFID tags, each corresponding to a different electrode identifier, will be designated as 29a, 29b. 29n, for example 29a, 29b, and 29c for <NUM> tags corresponding to <NUM> different electrode identifiers.

As mentioned above, and referring again to <FIG>, the antennas <NUM> are disposed at a location <NUM> for capturing signals from the RFID tags <NUM> which are attached to electrodes <NUM> in that location. In one or more examples, the location is the vicinity of an EAF. In other examples, the location <NUM> is in the vicinity of an electrode adding station. In another example the location is in the vicinity of a tilt table <NUM> where electrodes are moved from a horizontal orientation to a vertical orientation when being added to an electrode column. In other examples, the location is a vicinity within <NUM> to <NUM> (<NUM> to <NUM> feet) from the EAF <NUM>. In other examples the vicinity is within <NUM> to <NUM> (<NUM> to <NUM> feet) of the EAF <NUM>, and in still another example the vicinity is within <NUM> to <NUM> (<NUM> to <NUM> feet) of the EAF.

The RFID tag reader <NUM> includes a processor <NUM> configured for receiving signals from the at least one antenna <NUM> and converting the signals to electrode identifiers. The RFID tag reader <NUM> also includes memory <NUM> for storing a set of the electrode identifiers corresponding to the electrodes 11a, 11b and 11c at a location <NUM>, such as for example in the vicinity of the EAF <NUM>. The reader <NUM> periodically reads the tags 29a, 29b, 29c attached to the electrodes 11a, 11b, 11c at the location <NUM> and populates the memory registers <NUM> with the electrodes' corresponding electrode identifiers.

The tag reader <NUM> is connected to the furnace monitor <NUM> by a connection <NUM>, such as by an Ethernet connection. The furnace monitor processor <NUM> is configured for receiving the set of electrode identifiers stored in the tag reader memory <NUM>, associating the electrode identifiers with the EAF data corresponding to the specific EAF <NUM> in which the electrode was used, and storing the association in the EAF monitor memory <NUM>. Examples of the EAF data include the electrical data obtained by the electrical meter <NUM> described above, the process data obtained by the one or more PLCs described above, or combinations of both.

The furnace monitor processor <NUM> can be configured to use the association of the electrode identifier and EAF data described above to generate EAF data for specific electrodes and display this information on the local viewer system <NUM> during the operation of the EAF <NUM> to assist furnace operators and technicians during furnace operation.

The furnace monitor processor <NUM> can also be configured to process the EAF data for specific electrodes to generate current and past operating parameters of the electric arc furnace <NUM> for, or in relation to, specific electrodes including operating trends, historical trends, statistical tables and graphical representations, heat analysis reports, correlations and other analyses to better assist the viewer in evaluating the operation of the furnace <NUM>. The processor <NUM> can be configured to generate reports and transmit the reports to the local viewer <NUM>, the reports detailing the historical operation of the furnace in relation to specific electrodes using the association of the electrode identifier and EAF data described above. These reports include, for example, a single heat summary which includes the electrodes used in the heat, a daily heat summary which includes the electrodes used in all of the day's heats, daily shift heat summary and pertaining electrodes, weekly heat summary and pertaining electrodes, monthly heat summary and pertaining electrodes, heat summary by date range and conditions and pertaining electrodes, performance reporting in graphical format for pertaining electrodes, refractory wear reporting includes electrodes used, event log reporting pertaining to specific electrodes, specific electrode consumption reporting, and specific electrode usage and specific inventory reporting. These reports can now all be associated or correlated with specific electrodes by using the electrode identifiers described above.

Alternatively, or in addition to the local processing and displaying of the association of the electrode identifier and EAF data described above, the furnace monitor <NUM> can process portions of the EAF data and send the processed EAF data and unprocessed EAF data via the Internet <NUM> to the remote central server <NUM> disposed at a different location from the monitor <NUM> for storage in the database <NUM>. The remote server <NUM> includes a processor <NUM> configured to use the association of the electrode identifier and EAF data described above and/or to make the association of the electrode identifier and EAF data described above to generate EAF data for specific electrodes, and/or indicate specific electrodes associated with particular EAF data, display this information on the remote viewer system <NUM> during the operation of the EAF <NUM> to assist furnace operators during furnace operation.

The server processor <NUM> can also be configured to process the EAF data for specific electrodes to allow a user to view current and past operating parameters of the electric arc furnace <NUM> for, or in relation to, specific electrodes including operating trends, historical trends, statistical tables and graphical representations, heat analysis reports, correlations and other analyses via the Internet portal <NUM> to better assist the viewer in evaluating the operation of the furnace <NUM>. Authorized users may view reports via the portal detailing the historical operation of the furnace in relation to specific electrodes using the association of the electrode identifier and EAF data described above. These reports include, for example, a single heat summary, a daily heat summary, daily shift heat summary, weekly heat summary, monthly heat summary, heat summary by date range and conditions, performance reporting in graphical format, refractory wear reporting, event log reporting, electrode consumption reporting, and electrode usage and inventory reporting all for (i.e. in relation to) specific electrodes.

Other examples of the EAF data can include, but is not limited to, a time or time period, that the electrode was detected at the location <NUM>, such as the EAF vicinity, and/or the time or time period that an electrode which was previously detected at the location <NUM> was no longer detected at that location. The furnace monitor processor <NUM> can be configured to receive this EAF data from the tag reader <NUM> by periodically reading the tag reader memory <NUM>.

Determining the number of heats/add requires first knowing when an electrode is added to each electrode column and/or how many are added over the subject period of time. As discussed above, the determination that an electrode is added to one or more of the electrode columns is advantageously performed automatically.

Disclosed herein but not claimed is a method of determining that an electrode is added to an electrode column including: monitoring RFID tags at a location within range of the antennas <NUM>;. receiving electrode identifiers from an RFID tag reader corresponding to the signals received from the RFID tags attached to electrodes disposed at the location <NUM>; placing electrode identifiers in memory registers within the RFID reader no less than every N minutes, wherein. <NUM><N<<NUM>; an electrode monitor reading the RFID reader memory and determining that an RFID identifier which was read previously is now no longer read from the memory thereby identifying that RFID identifier as a missing electrode identifier; associating the missing electrode identifier with an electrode column using electrode clamp data and/or electrode mast data.

With reference again to <FIG>, the method for associating the missing electrode identifier with an electrode column using electrode clamp data and/or electrode mast data can include monitoring two operating parameters of the electric arc furnace <NUM>. Disclosed herein, the first monitored operating parameter may be the movement of the electrode mast <NUM>, by a column position transducer or a pressure transducer. Also the position of the clamp <NUM> can be monitored. The electrode column <NUM>, <NUM>, or <NUM> associated with the clamp <NUM> which moves after the missing electrode is detected is determined to be the column <NUM>, <NUM>, <NUM> receiving the missing electrode identified and determined to be the added electrode. The method can further include determining the electrical phase of the EAF associated with the electrode column which receives the added electrode and associating the electrode identifier with that electrical phase.

Thus, according to the above, a control signal may directly indicate the electrode column which receives the added electrode. The furnace monitor processor <NUM> is configured to associate the electrode identifier with the electrode column <NUM>, <NUM>, <NUM> and store this association in memory <NUM>. This association can be transferred to remote server <NUM> for storage in database <NUM> and further processing by processor <NUM> to generate the current and past operating parameters and reports discussed above.

The operation of the electrode monitoring system <NUM> includes the tag reader capturing signals from the RFID tags attached to each of the graphite electrodes using one or more of the antennas which are disposed at a location <NUM>, such as for example the vicinity of the EAF; the tag reader converting the signals into an electrode identifier specifically identifying the graphite electrode located at the location <NUM>, and storing the electrode identifier in memory. The tag reader reads the electrode tags in this manner for each of the electrodes located at location <NUM> and stores the electrode identifiers as sets of identifiers in the reader's memory.

The electrode monitor controller periodically reads the tag reader memory to obtain the set of electrode identifiers and sends the set to the EAF monitoring server <NUM> via an internet connection. The EAF server processor <NUM> associates the electrode identifiers with specific furnace heats for which the electrodes were used for tracking the operation of the electrode while it is used in the EAF <NUM>.

A method for monitoring the graphite electrodes for the electric arc furnace <NUM> generally comprises: capturing a signal from a radio frequency identification (RFID) tag, attached to a graphite electrode; converting the signal into an electrode identifier identifying the graphite electrode; transmitting the electrode identifier to an electric arc furnace monitor; receiving a set of electrode identifiers from the RFID tag reader at the monitor, the electrode identifiers obtained from signals from radio frequency identification (RFID) tags attached to graphite electrodes disposed near the location of the antenna, such as for example in the vicinity of the EAF; associating the electrode identifiers with EAF data corresponding to the specific electrodes; and storing the association in the EAF monitor memory.

The systems and methods of electrode identification described herein allow EAF operators and service personnel to determine which specific electrodes are used in each particular heat. Knowing the specific electrodes which are used in a heat enables operators and service personnel to correlate electrode performance with electrode batches thereby improving the performance of the graphite electrodes and/or EAF.

The furnace monitoring system <NUM> uses state of the art hardware and software to record the full range of operational parameters, including chemical ones, which make up the total operating environment of the electric arc furnace. The present invention provides on-line, real time access to the EAF data correlated to specific electrodes using the electrode identifiers detected and monitored as described herein.

Claim 1:
A graphite electrode (<NUM>) comprising;
an electrode body (<NUM>) formed of graphite having oppositely disposed first (<NUM>) and second (<NUM>) ends; and
a threaded connector (<NUM>, <NUM>) disposed at at least one end;
wherein the electrode (<NUM>) further includes a tag (<NUM>) attached to the body (<NUM>), wherein the tag (<NUM>) creates a non-line-of-sight signal representing an electrode identifier, wherein the threaded connector (<NUM>, <NUM>) is at least one of a pin and a socket,
characterized in that the tag (<NUM>) is attached to at least one of the pin and the socket.