JP5880303B2 - Electric melting furnace control system and glass manufacturing method using electric melting furnace control system - Google Patents

Description

  The present invention heats an object to be heated in a melting furnace by distributing and supplying electric power through a branch circuit branched from a main circuit to each of a plurality of electrodes arranged as a plurality of electrode pairs in the melting furnace. The present invention relates to a control system for an electric melting furnace and a glass manufacturing method using the control system for the electric melting furnace.

  A melting technique in which an object to be heated (for example, glass) is directly energized to be in a molten state has been adopted in many melting furnaces. As an advantage of this melting technology, compared with burner heating using LPG, heavy oil, etc. as fuel, it does not generate fuel-derived exhaust gas, can suppress the scattering of raw materials of the heated object, and is excellent in terms of environmental protection The temperature can be easily increased and soaking can be easily performed. On the other hand, the disadvantages of this melting technique are as follows. In order to directly energize the object to be heated, a large number of electrodes must be inserted into the object to be heated in the melting furnace. For this reason, it takes time and effort to manage and construct a large number of electrodes. Moreover, when the electrode surface used for a long period of time changes in quality and becomes brittle, the electrode fragments are mixed as foreign matter into the article in which the article to be heated is molded. Further, when a component that is easily reduced among the components of the object to be heated is reduced by the electrode component, foreign matter is also generated. Furthermore, if the electrode is shortened to about several centimeters due to breakage, the vicinity of the electrode installation on the furnace wall and the hearth tends to be overheated, and the refractory near the electrode and the electrode heating equipment itself may be damaged. In addition, excess thermal energy is scattered from the furnace wall and hearth, which tends to hinder energy saving.

  As a technique for detecting such an electrode abnormality of a melting furnace, for example, Patent Document 1 discloses that a furnace wall temperature in the vicinity of an electrode is measured at a constant short interval, and if the current temperature exceeds the maximum temperature, a serious failure is determined. In addition, a technique is described in which a major failure and a minor failure are determined according to the degree of the temperature difference between the current temperature and the measured temperature a predetermined time ago. The technique described in Patent Document 1 seeks to detect an upper electrode abnormality at an early stage and adjust the electrode position before electrode wear proceeds more than allowable. For the early detection of the upper electrode abnormality, Considering the degree of the temperature difference between the temperature and the measured temperature before a predetermined time, the major failure and the minor failure are determined.

  Further, for example, Patent Document 2 describes a technique for setting a predetermined delay time until the electrode is pulled up after the occurrence of an overcurrent so as to optimize the electrode rapid pull-up timing when the overcurrent is generated. Also, for example, in Patent Document 3, the movement trajectory of the electrode tip is classified into a plurality of patterns based on the electric resistance value in the furnace, and adjustment of the coke addition amount and estimation of the electrode depth are performed according to the classified electrode depth pattern. The technology which stabilizes electric furnace operation by this is described.

JP-A-61-83879 JP 61-60554 A JP-A-6-341773

  The technique described in Patent Document 1 described above measures the furnace wall temperature in the vicinity of the electrode to determine the wear of the electrode, and does not directly measure the temperature of the electrode itself. It was difficult to detect well, and as a result, it was difficult to accurately determine the wear of the electrodes. Therefore, there is room for improvement from the viewpoint of accurately detecting the wear state of the electrode and accurately determining the wear of the electrode.

  In addition, as in the technique described in Patent Document 1, when the electrode abnormality is detected based on the measured value of the furnace wall temperature in the vicinity of the electrode and the electrode wear is determined, the criterion for determining the electrode wear is determined. The information (for example, the measured value of the furnace wall temperature in Patent Document 1) may change due to factors other than electrode wear such as failure of the measuring instrument itself or noise. It became clear from the data analysis result during operation of the electric melting furnace by the present inventor that the change in the information becomes an obstacle to accurately determining the wear of the electrode. Before such data analysis results are known, skilled workers who perform inspection work on electric melting furnaces check various data on the electric melting furnace, check the field, etc., and wear electrodes based on intuition and experience. However, since it took a lot of labor and time to respond, it was possible to reduce the work burden on the worker and to quickly perform the inspection work of the electric melting furnace, etc. There was room for improvement from the point of view.

  Similarly, in the techniques described in Patent Documents 2 and 3 described above, since the state of the electrode is detected based on the overcurrent and the electric resistance in the furnace, the information is caused by factors other than the wear of the electrode. If it has changed, it may be difficult to accurately grasp the state of the electrode.

  An object of the present invention is to provide a control system for an electric melting furnace that can accurately determine the wear of an electrode, reduce an operator's work load, and quickly perform an inspection operation of the electric melting furnace, and the like. It is providing the glass manufacturing method using the control system of an electric melting furnace.

  The first invention distributes and supplies power via a branch circuit branched from the main circuit to each of a plurality of electrodes arranged as a plurality of electrode pairs in the melting furnace, and supplies a heated object in the melting furnace. A control system for an electric melting furnace for heating, a control device for controlling the electric melting furnace, a branch circuit detection means for detecting power information of the branch circuit, and a main circuit for detecting power information of the main circuit Detection means, and the control device includes a determination unit that determines wear of the electrode based on power information of the branch circuit and power information of the main circuit.

  From the results of data analysis during operation of the electric melting furnace by the present inventor, it was found that when the electrode was actually worn, the power information of both the branch circuit and the main circuit fluctuated. Therefore, in the first invention, the power information of the main circuit is detected in addition to the power information of the branch circuit, and the determination unit determines the wear of the electrode based on the power information of both the branch circuit and the main circuit. did. As a result, it is possible to detect the wear state of the electrode with high sensitivity based on the power information of both the branch circuit and the main circuit. Can do. Therefore, for example, even when the power information of the branch circuit changes due to factors other than electrode wear, the wear of the electrode can be accurately determined, reducing the work burden on the operator and Inspection work can be performed quickly.

  According to a second aspect of the invention, in the configuration of the first aspect of the invention, the branch circuit detection means includes electrode current detection means for detecting an electrode current value of the branch circuit, and the main circuit detection means includes the Main circuit current detection means for detecting a main circuit current value of the main circuit is provided, and the determination unit is configured to determine wear of the electrode based on the electrode current value and the main circuit current value. .

  According to the above configuration, not only the electrode current value but also the main circuit current is provided with a simple configuration including the electrode current detection means for detecting the electrode current value of the branch circuit and the main circuit current detection means for detecting the main circuit current value. The wear of the electrode can be accurately determined in consideration of the value.

  According to a third aspect of the present invention, in the configuration of the second aspect of the present invention, the determination unit determines that the electrode current value of any one specific electrode of the plurality of electrode pairs decreases by a predetermined value or more and the specific electrode current value decrease condition is satisfied. When the main circuit current value decreases more than a predetermined value and the main circuit current value decrease condition is satisfied, the specific electrode is determined to be worn out.

  According to the above configuration, it is possible to determine the wear of the electrode with higher accuracy by determining whether or not the electrode current value and the main circuit current value of the specific electrode are decreased by a predetermined value or more.

  According to a fourth aspect of the present invention, in the configuration of the third aspect of the present invention, the determination unit is configured so that the specific electrode current value lowering condition and the main circuit current value lowering condition are satisfied, and the counter electrode is paired with the specific electrode When the counter electrode current value lowering condition is satisfied when the electrode current value decreases by a predetermined value or more, it is determined that the specific electrode is worn out.

  According to the above configuration, it is possible to more accurately determine electrode wear by determining whether not only the electrode current value and the main circuit current value of a specific electrode but also the electrode current value of the counter electrode decreases by a predetermined value or more. it can.

  According to a fifth invention, in the configuration according to any one of the first to fourth inventions, as the branch circuit detection means, an electrode for detecting a voltage value between the electrodes between the branch circuits supplying power to the electrode pair. When the inter-voltage detection means is provided, and the determination unit increases the inter-electrode voltage value of any one of the plurality of electrode pairs by a predetermined value or more, and the inter-electrode voltage value increase condition is satisfied, The electrode belonging to the specific electrode pair is determined to be worn out.

  According to the above configuration, the wear of the electrode can be determined with higher accuracy by determining whether or not the voltage value between the electrodes has increased by a predetermined value or more.

  6th invention is the structure in any one of the said 1st-5th invention, Furthermore, The temperature detection means which detects the cooling water temperature of the cooling water which cools the melting furnace insertion part of the said electrode is provided, When the cooling water temperature for cooling the melting furnace insertion portion of any one of the plurality of electrodes increases by a predetermined value or more and the cooling water temperature increase condition is satisfied, the specific electrode is It is comprised so that it may determine with having worn out.

  According to the above configuration, the wear of the electrode can be determined with higher accuracy by determining whether or not the cooling water temperature has increased by a predetermined value or more.

  According to a seventh invention, in any one of the first to sixth inventions, the branch circuit detection means includes electrode current detection means for detecting an electrode current value of the branch circuit, and Current value calculation means for calculating an electrode current value is provided, and the determination unit is configured to determine wear of the electrode based on a calculation result of the current value calculation means.

  According to the above configuration, the electrode current value is calculated by the current value calculation means by effectively using the electrode current value, and the wear of the electrode is determined with higher accuracy in consideration of not only the electrode current value but also the calculation result of the electrode current value. be able to.

  According to an eighth aspect of the present invention, in the configuration of the seventh aspect, the current value calculation means includes a sum of electrode current values of one electrode of the plurality of electrode pairs and the other of the plurality of electrode pairs. The sum of the electrode current values of the two electrodes is calculated, and the determination unit generates a difference of a predetermined value or more between the sum of the electrode current values of the one electrode and the sum of the electrode current values of the other electrode. It is configured so as to determine the wear of the electrode on the condition that there is not.

  According to the above configuration, the wear of the electrode can be determined with higher accuracy in consideration of the sum of the electrode current values of one and the other electrodes of the plurality of electrode pairs.

  According to a ninth aspect, in the configuration according to the eighth aspect, the determination unit has a difference of a predetermined value or more between the sum of the electrode current values of the one electrode and the sum of the electrode current values of the other electrode. If the electrode current value difference condition is satisfied and the electrode current value of any one of the plurality of electrode pairs decreases by a predetermined value or more and the specific electrode current value decrease condition is satisfied, It is determined that an abnormality has occurred in the branch circuit that supplies power to the electrodes.

  According to the above configuration, it is possible to determine an abnormality in the branch circuit that supplies power to a specific electrode in consideration of the electrode current value and the sum of the electrode current values of one electrode and the other electrode of each of the plurality of electrode pairs. .

  According to a tenth aspect of the present invention, in any one of the seventh to ninth aspects, the main circuit detection unit includes a main circuit current detection unit that detects a main circuit current value of the main circuit. The current value calculation means calculates a sum of electrode current values of one electrode of each of the plurality of electrode pairs or a sum of electrode current values of the other electrode of the plurality of electrode pairs, and the determination unit includes: It is configured to determine the wear of the electrode on the condition that a difference of a predetermined value or more does not occur between the main circuit current value and the sum of the electrode current values of the one or the other electrode.

  According to the above configuration, the wear of the electrode can be determined with higher accuracy in consideration of the main circuit current value and the sum of the electrode current values of one or the other electrode of each of the plurality of electrode pairs.

  According to an eleventh aspect, in the configuration according to the tenth aspect, the determination unit generates a difference of a predetermined value or more between the main circuit current value and a sum of the electrode current values of the one or the other electrode. When the main circuit current value difference condition is satisfied, it is determined that an abnormality has occurred in the main circuit.

  According to the above configuration, the abnormality of the main circuit can be determined in consideration of the main circuit current value and the sum of the electrode current values of one or the other electrode of each of the plurality of electrode pairs.

  A twelfth aspect of the present invention is the power supply apparatus according to any one of the first to eleventh aspects, wherein the electric melting furnace supplies power to the plurality of electrodes from the main circuit via a branch circuit. The branch circuit detection means is configured to detect power information of each branch circuit of the plurality of power supply devices, and the main circuit detection means is configured to detect the power supply devices of the plurality of power supply devices. The power information of each main circuit is configured to be detected, and the determination unit is configured to determine wear of the electrode in each power supply device of the plurality of power supply devices.

  According to the above configuration, electrode wear can be determined for each of the plurality of power supply devices, and wear of a large number of electrodes provided in a wide range in the electric melting furnace can be determined finely for each of the plurality of power supply devices. can do. Therefore, it is possible to accurately determine the wear of a large number of electrodes provided in the electric melting furnace, and it is possible to quickly perform inspection work over a wide range of the electric melting furnace.

  13th invention is a glass manufacturing method which manufactures molten glass using the control system of the electric melting furnace of any one structure of the said 1st-12th invention.

  According to the above configuration, it becomes possible to grasp the wear of the electrode and the abnormality of the heating equipment with high accuracy and early, and it is possible to minimize the damage to the electrode, the refractory around the electrode, and the heating equipment. Moreover, at the time of electrode wear, the recovery time until the electric melting furnace is restarted can be shortened, and the molten glass can be produced efficiently and at low cost.

FIG. 1 is a schematic view of an electric melting furnace, (a) is a partial plan view of the electric melting furnace as viewed from above, and (b) is an electric diagram at the position AA ′ in (a). It is a vertical side view of a melting furnace. FIG. 2 is a power supply system diagram of the electric melting furnace. FIG. 3 is a block diagram of an electric melting furnace control system. FIG. 4 is a diagram for explaining the contents of the input processing control by the input processing unit, (a) is a flowchart of the input processing control, and (b) is a graph for explaining the data processing in the input processing control. It is. FIG. 5 is a flowchart of the electric melting furnace abnormality determination control by the determination unit. FIG. 6 is a flowchart of the electric melting furnace abnormality determination control by the determination unit. FIG. 7 is a graph showing changes in the electrode current value for each electrode when the connection terminal of the specific electrode is loosened. FIG. 8 is data showing various detected values when short-term wear of a specific electrode occurs, (a) the electrode current value of each electrode on the W side, and (b) the electrode current value of each electrode on the E side. (C) It is a graph which shows each change of the main circuit electric current value, (d) The voltage value between electrodes of each electrode pair, (e) The cooling water temperature of each electrode. FIG. 9 is a graph showing a change in electrode current value for each electrode when short-term wear of a specific electrode occurs. FIG. 10 is a graph showing changes in the electrode current value for each electrode when a specific electrode is worn for a long time.

[Overall configuration of electric melting furnace]
Based on FIG. 1, the whole structure of the electric melting furnace 100 of this invention is demonstrated. FIG. 1 is a schematic view of an electric melting furnace 100. (A) is the partial top view which looked at the electric melting furnace 100 from upper direction. (B) is a longitudinal side view of the electric melting furnace 100 at the position of AA ′ in (a). The electric melting furnace 100 is a continuous melting furnace used for producing a homogeneous molten glass G to cope with continuous molding of glass fibers.

  As shown in FIG. 1, an electric melting furnace 100 is equipped with a charging port 1 for charging a glass raw material, a melting furnace 2 configured in a tank shape with a ceramic refractory, and a bottom 2 </ b> S of the melting furnace 2. A plurality of electrode pairs 3 and a throat 4 and a foreground 5 for taking out a molten glass G melted in the melting furnace 2 are provided. After the glass raw material is homogeneously mixed, the glass raw material is transported to the charging port 1 by a transporting means such as a conveyor (not shown) and charged into the melting furnace 2. The glass raw material thrown into the melting furnace 2 is heated and becomes a molten state. The molten glass G heated to a homogeneous state reaches the fore-hearth 5 through the throat 4 and is drawn into a thin stream by a bushing (not shown) arranged in the molding area. The glass fiber drawn out from the bushing is cooled, and then a sizing agent is applied to the glass fiber so that the glass fiber is bundled and formed into a glass fiber bundle. Note that the glass forming method described above is merely an example, and any other known method may be used to form the glass. For example, the molten glass G may be formed in a plate shape using an arbitrary method such as a float method or a downdraw method.

  As shown in FIG. 1, the plurality of electrode pairs 3 are disposed on the bottom 2 </ b> S of the melting furnace 2. Each electrode pair 3 is composed of a pair of electrodes that are long in the vertical direction and are arranged at predetermined intervals in the longitudinal direction of the melting furnace 2. In FIG. 1, the electrode on the inlet 1 side of the pair of electrodes constituting the electrode pair 3 is indicated by W, and the electrode on the throat 4 side is indicated by E. Each electrode W, E is made of molybdenum. The pair of electrodes W and E melt the glass raw material by Joule heat generated by energization between the electrodes. Each of the electrodes W and E is disposed on the bottom 2S of the melting furnace 2 so as to be vertically movable so as to penetrate the bottom 2S of the melting furnace 2. An electrode moving means (not shown) is provided in the melting furnace insertion portion of each electrode W, E. The electrode moving means adjusts the protruding length of the electrodes W and E from the bottom surface of the melting furnace 2 into the melting furnace 2.

  As shown in FIG. 1 (a), the electric melting furnace 100 includes a first power supply device R1 for heating a region near the charging port 1 and a side near the throat 4 as a plurality of power supply devices. Power supply of the second power supply device R2 for heating the region on the one side in the horizontal direction of the region and the third power supply device R3 for heating the region on the other side in the lateral direction near the throat 4 Equipment. The three electrode pairs 3 are connected to the first power supply device R1, the second power supply device R2, and the third power supply device R3, respectively. The three electrode pairs 3 of each of the power supply devices R1 to R3 are arranged so as to be substantially equidistant in the longitudinal direction and the short direction of the melting furnace 2.

  As shown in FIG. 1B, a cooling device 6 is provided at the melting furnace insertion portion of each electrode W, E. The cooling device 6 is disposed so as to be located on the bottom surface side of the bottom 2S of the melting furnace 2. The cooling device 6 cools the melting furnace insertion part of each electrode W and E with cooling water. Cooling water is individually supplied and discharged to each cooling device 6, and each cooling device 6 individually cools the melting furnace insertion portion of each electrode W, E. The drainage section of each cooling device 6 is provided with a temperature detector 7 that detects the cooling water temperature T of the cooling water drained from each cooling device 6. The temperature detector 7 individually detects the cooling water temperature T of the cooling water after cooling the electrodes W and E.

[Configuration of electric melting furnace power supply system and control system]
Based on FIG.2 and FIG.3, the structure of the electric power supply system of the electric melting furnace 100 and a control system is demonstrated. FIG. 2 is a power supply system diagram of the electric melting furnace 100. FIG. 3 is a block diagram of a control system of the electric melting furnace 100. In FIG. 2, only the power supply system of the first power supply device R1 is described in detail, but the power supply systems of the second and third power supply devices R2 and R3 are also the power of the first power supply device R1. The configuration is the same as that of the supply system. In FIG. 3, only the input / output devices of the first power supply device R1 are shown as the input / output devices to the control device 30, but the input / output devices of the second and third power supply devices R2 and R3 are the same. It is the composition. In the following description, the power supply system and input / output devices of the first power supply device R1 will be described as an example, but the power supply systems and input / output devices of the second and third power supply devices R2 and R3 have the same configuration. is there.

  As shown in FIG. 2, the power supply system of the electric melting furnace 100 includes a primary power supply 10 as a power supply source, and first to third power supply devices R1 to R3 to which power from the primary power supply 10 is distributed and supplied. Is provided. The primary circuit provided with the primary power supply 10 is provided with a primary voltage detector 12 that detects voltage fluctuation of the primary power supply 10. In this electric melting furnace 100, an AC two-phase power source is adopted as the primary power source 10, and various devices in the power supply system are also configured with AC specifications corresponding to the AC power source.

  The power distributed and supplied from the primary power supply 10 to the first to third power supply devices R1 to R3 is supplied to the main circuit A of each power supply device R1 to R3 via the transformer 11 provided in each power supply device R1 to R3. Supplied. The transformer 11 converts the power supplied from the primary power supply 10 to each of the power supply devices R1 to R3 into a predetermined power and supplies it to the main circuit A. That is, the transformer 11 functions as a power regulator that regulates the power supplied to the main circuit A. The control device 30 outputs a power maintenance command to the transformer 11 and performs control so that the power of the main circuit A is maintained at a predetermined power. The electric power supplied to the main circuit A is distributed and supplied to each electrode pair 3 via the branch circuit B branched from the main circuit A. The main circuit A includes a main circuit current detector 13 that detects a main circuit current value and a main circuit voltage detector 14 that detects a main circuit voltage value. The main circuit current detector 13 includes a current transformer 13a provided in the main circuit A and a main circuit current converter 13b connected to the current transformer 13a. The main circuit current detector 13 transforms the current of the main circuit A by the current transformer 13a, converts the transformed current into a predetermined signal by the main circuit current converter 13b, and outputs it to the control device 30. The main circuit voltage detector 14 includes a transformer 14a provided in the main circuit A and a main circuit voltage converter 14b connected to the transformer 14a. The main circuit voltage detector 14 transforms the voltage of the main circuit A with the transformer 14a, converts the transformed voltage into a predetermined signal with the main circuit voltage converter 14b, and outputs it to the control device 30.

  The branch circuit B is provided with an electrode current detector 17 for detecting an electrode current value of power supplied to each electrode W, E of each electrode pair 3. The branch circuit B is connected to an inter-electrode voltage detector 18 that detects an inter-electrode voltage value of electric power supplied to each of the electrode pairs 3. The electrode current detector 17 includes a current transformer 17a provided in the branch circuit B and an electrode current converter 17b connected to the current transformer 17a. The electrode current detector 17 transforms the currents of the electrodes W and E by the current transformer 17 a, converts the transformed current into a predetermined signal by the electrode current converter 17 b, and outputs the signal to the control device 30. The interelectrode voltage detector 18 includes a transformer 18a connected to the branch circuit B and an interelectrode voltage converter 18b connected to the transformer 18a. The interelectrode voltage detector 18 transforms the voltage between the electrodes W and E by the transformer 18a, converts the transformed voltage into a predetermined signal by the interelectrode voltage converter 18b, and outputs the signal to the control device 30.

  As shown in FIG. 3, the control device 30 of the electric melting furnace 100 comprehensively controls various electric devices of the electric melting furnace 100 so as to continuously operate the electric melting furnace 100. The control device 30 includes a CPU such as a sequencer built in a control panel of the electric melting furnace 100, a personal computer connected to the CPU, and the like. The controller 30 is connected to an electrode current detector 17 and an interelectrode voltage detector 18 as branch circuit detection means. The control device 30 receives an electrode current value and an interelectrode voltage value as power information of the branch circuit B, respectively. The control device 30 is connected to a main circuit current detector 13 and a main circuit voltage detector 14 as main circuit detection means. A main circuit current value and a main circuit voltage value as power information of the main circuit A are respectively input to the control device 30. The primary voltage detector 12 provided in the primary circuit is connected to the control device 30. The primary voltage value of the primary power supply 10 is input to the control device 30. A temperature detector 7 is connected to the control device 30. The controller 30 receives the cooling water temperature T after cooling the electrodes W and E.

  The control device 30 includes an input processing unit 31 that performs arithmetic processing on input data from the various detection devices described above. The input processing unit 31 includes a fluctuation speed calculation unit 32, a change temperature calculation unit 33, a current value calculation unit 34, and a power consumption calculation unit 35. The fluctuation speed calculator 32 calculates the fluctuation speeds Va, Vb, Vc, Vd, Ve of the electrode current value, the main circuit current value, the interelectrode voltage value, the main circuit voltage value, and the primary voltage value. The change temperature calculation unit 33 calculates the cooling water change temperature ΔT. The current value calculation unit 34 calculates the electrode current values of the plurality of electrode pairs 3 of the first power supply device R1. The power consumption calculator 35 calculates the amount of power supplied to the main circuit A. The fluctuation speed calculator 32, the change temperature calculator 33, the current value calculator 34, and the power consumption calculator 35 execute input processing control. The power consumption calculator 35 calculates the amount of power supplied to the main circuit A based on the main circuit current value detected by the main circuit current detector 13 and the main circuit voltage value detected by the main circuit voltage detector 14. Calculate.

  The control device 30 includes a determination unit 40 that determines an abnormality of the electric melting furnace 100 based on a calculation result by the input processing unit 31. The determination unit 40 determines abnormality of the electric melting furnace 100 other than wear of the electrodes W and E and wear of the electrodes W and E. The determination unit 40 includes an initial condition setting unit 41 that sets and changes a threshold value used for various determinations. The term “wear and tear of electrodes W and E” here means that the electrodes W and E are worn and shortened in the long term, and that they are broken and shortened in the short term, and the electrodes are short and long term. In a broad sense, the surface of W and E changes in quality and becomes brittle.

  The control panel or the like of the electric melting furnace 100 is provided with a notification unit 50 that notifies the operator of various types of information related to the electric melting furnace. The notification unit 50 includes an information notification unit 51 that displays various types of information from the control device 30, and an abnormality notification unit 52 that displays the wear of the electrodes W and E determined by the determination unit 40 and the abnormality of the electric melting furnace 100. Prepare. The information notification unit 51 is configured by a display unit such as a lamp or a display that visually displays various information from the control device 30, and an audio unit such as a buzzer or speaker that audibly transmits various information from the control device 30. Is done. Similar to the information notification unit 51, the abnormality notification unit 52 includes a display unit such as a lamp and a display, and a sound unit such as a buzzer and a speaker. The abnormality notifying unit 52 individually notifies various abnormalities determined by the determining unit 40 for each abnormality. The control device 30 includes an output unit 44. The output unit 44 outputs various information from the control device 30 and the determination result determined by the determination unit 40 to the notification unit 50.

  The control device 30 includes a power amount control unit 45 that controls the amount of power supplied to the main circuit A based on the calculation result by the input processing unit 31. The power amount control unit 45 controls the power supply command to be output to the transformer 11 based on the calculation result by the power consumption calculation unit 35 so that the power supplied to the main circuit A is maintained at a predetermined power. That is, the control system for the electric melting furnace 100 executes constant power control for maintaining the amount of power supplied to the main circuit A at a predetermined power.

[Details of electric melting furnace control]
Based on FIGS. 4-6, the concrete control content of the electric melting furnace 100 is demonstrated. FIG. 4 is a diagram for explaining the contents of input processing control by the input processing unit 31. (A) is a flowchart of input processing control. (B) is a graph for explaining data processing in input processing control. 5 and 6 are flowcharts of the electric melting furnace abnormality determination control by the determination unit 40.

  The input processing unit 31 of the control device 30 includes an electrode current value detected by the electrode current detector 17, a main circuit current value detected by the main circuit current detector 13, and an electrode detected by the interelectrode voltage detector 18. The inter-voltage value, the main circuit voltage value detected by the main circuit voltage detector 14, and the primary voltage value detected by the primary voltage detector 12 are always input.

  As shown in FIG. 4A, the input processing unit 31 collects data for each first predetermined time ta (for example, 15 seconds) of each input detection value (step S1). Then, the input processing unit 31 averages a plurality of data (four data when ta = 15 seconds and tb = 1 minute) within a second predetermined time tb (for example, 1 minute) longer than the first predetermined time ta. The value Da is calculated every second predetermined time tb (step S2). Then, the input processing unit 31 compares the average value Da calculated every second predetermined time tb with the previous average value Da ′, and when the average value Da is larger than the previous average value Da ′. Then, the maximum value Dmax among the plurality of data targeted for the average value Da is adopted as the predetermined time data D. On the contrary, when the average value Da is smaller than the previous average value Da ′, the input processing unit 31 sets the minimum value Dmin among a plurality of data targeted for the average value Da as predetermined time data. This is adopted as D (step S3).

  The graph shown in FIG. 4B is a graph showing the data processing of the input processing unit 31 described above. The line graph shown in the figure is a graph obtained by connecting a plurality of data collected every first predetermined time ta with a straight line. In the time zone tb on the left side of FIG. 4B, the input processing unit 31 collects data D1, D2, D3, D4 for each first predetermined time ta, and these data D1, D2, D3, D4. The average value Da is calculated together with the collection of the data D4. Since the current average value Da is smaller than the previous average value Da ′, the input processing unit 31 sets the data D2 that is the minimum value Dmin among the plurality of data D1, D2, D3, and D4 for a predetermined time. Adopted as data D. Further, in the time zone tb on the right side of FIG. 4B, the input processing unit 31 collects data D1, D2, D3, D4 for each first predetermined time ta, and these data D1, D2, D3. , D4 average value Da is calculated along with the collection of data D4. Since the current average value Da is greater than the previous average value Da ′, the input processing unit 31 sets the data D3 that is the maximum value Dmax among the plurality of data D1, D2, D3, and D4 for a predetermined time. Adopted as data D. As described above, the input processing unit 31 compares the average value Da calculated every second predetermined time tb with the previous average value Da ′, and determines the maximum value Dmax or the minimum value Dmin among the plurality of data for the predetermined time. By adopting the configuration as the data D, the fluctuation speed V (Va, Vb, Vc, Vd, Ve) of the predetermined time data D to be described later without missing the maximum value Dmax and the minimum value Dmin of the plurality of data. Can be accurately calculated in a form close to the fluctuation speed of the actual plurality of data.

  As shown in FIG. 4A, the fluctuation speed calculation unit 32 of the input processing unit 31 uses the predetermined time data D described above, and the predetermined time data D ′ adopted last time and the predetermined time data D adopted this time. Then, the fluctuation speed V is calculated (step S4). In this embodiment, since the predetermined time data D ′ and D are calculated every second predetermined time tb (every minute), the fluctuation speed V is expressed by the formula: (D−D ′) / (D × tb ) And its unit is% / min (percent / minute). In this case, instead of calculating the fluctuation speed V by the above-described equation, the variation velocity V may be calculated by an equation (D−D ′) / tb that appears as an inclination in FIG.

  The input processing unit 31 calculates the average value Da every second predetermined time tb and uses the predetermined time data D as described above. The electrode current value, main circuit current value, interelectrode voltage value, main circuit voltage value, and This is performed for each collected data of the primary voltage value. The fluctuation speed calculation unit 32 also changes the electrode current value fluctuation speed Va, the main circuit current value fluctuation speed Vb, the interelectrode voltage value fluctuation speed Vc, and the main circuit voltage value fluctuation based on the input detection value. The speed Vd and the fluctuation speed Ve of the primary voltage value are calculated. Then, the fluctuation speed calculation unit 32 outputs the calculated fluctuation speeds to the determination unit 40 (step S5). Each fluctuation speed output to the determination unit 40 is used for determination in an electric melting furnace abnormality determination control described later.

  The cooling water temperature T of each electrode W, E detected by the temperature detector 7 is always input to the input processing unit 31 of the control device 30. The change temperature calculation unit 33 of the input processing unit 31 calculates the cooling water change temperature ΔT based on the input detection value.

  As shown in FIG. 4A, the change temperature calculation unit 33 collects data for each second predetermined time tb of the detected value of the coolant temperature T input to the input processing unit 31 (step S6). And the change temperature calculating part 33 calculates the average value Ta of the cooling water temperature T of all the electrodes W and E of 1st electric power supply apparatus R1 (step S7). Then, the change temperature calculation unit 33 calculates a value (T−Ta) obtained by subtracting the average value Ta from the individual cooling water temperatures T of the electrodes W and E as the cooling water change temperature ΔT of the electrodes W and E (step) S8). In this case, instead of calculating the cooling water change temperature ΔT by the above-described formula, the average value Ta is not used for calculating the cooling water change temperature ΔT, and the cooling water temperature T ′ collected last time and the cooling collected this time are not used. The difference from the water temperature T may be calculated as the cooling water change temperature ΔT. The change temperature calculation unit 33 calculates the above-described cooling water change temperature ΔT for each of the electrodes W and E of the first power supply device R1. And the change temperature calculating part 33 outputs the calculated cooling water change temperature (DELTA) T to the determination part 40 (step S5). The cooling water change temperature ΔT output to the determination unit 40 is used for determination in the electric melting furnace abnormality determination control described later. The change temperature calculation unit 33 is configured to collect detection value data of the cooling water temperature T at a second predetermined time tb longer than data such as electrode current values collected every first predetermined time ta. ing. Thereby, when abnormality arises in the electric melting furnace 100, the change of the cooling water temperature T whose change is slow compared with an electrode electric current value etc. can be correctly reflected on determination of electric melting furnace abnormality determination control.

  The current value calculation unit 34 of the input processing unit 31 includes the sum Iw of the electrode current values of one electrode W of the plurality of electrode pairs 3 of the first power supply device R1 and the plurality of electrodes of the first power supply device R1. The sum Ie of the electrode current values of the other electrode E of each pair 3 is calculated every second predetermined time tb based on the electrode current value data adopted as the predetermined time data D. Then, the current value calculation unit 34 outputs the calculated sum Iw and Ie of the electrode current values to the determination unit 40 together with the main circuit current value Ir adopted as the predetermined time data D. The sums Iw and Ie of the electrode current values output from the current value calculation unit 34 to the determination unit 40 and the main circuit current value Ir are used for determination in an electric melting furnace abnormality determination control to be described later.

  As shown in FIG. 5, the fluctuation speed Va of the electrode current value, the fluctuation speed Vb of the main circuit current value, the fluctuation speed Vc of the voltage value between the electrodes, the fluctuation speed Vd of the main circuit voltage value calculated by the input processing unit 31, the primary The voltage value fluctuation speed Ve, the sum Iw and Ie of the electrode current values, the main circuit current value Ir, and the cooling water change temperature ΔT are updated every second predetermined time tb and input from the input processing unit 31 to the determination unit 40. (Step S10).

  The initial condition setting unit 41 provided in the determination unit 40 is configured to be able to set and change various threshold values used for electric melting furnace abnormality determination control. That is, the initial condition setting unit 41 makes various determinations with respect to the above-described fluctuation speeds Va, Vb, Vc, Vd, Ve, the sum of electrode current values Iw, Ie, the main circuit current value Ir, and the cooling water change temperature ΔT. Various threshold values to be used can be set and changed. First, the determination unit 40 checks initial condition settings of various threshold values set in advance from data analysis results and the like described later (step S11), and based on the initial condition settings and various data calculated by the input processing unit 31. The electric melting furnace abnormality determination control shown below is executed.

  First, in the electric melting furnace abnormality determination control, the determination unit 40 determines whether the fluctuation speed Ve of the primary voltage value is equal to or higher than a predetermined threshold (step S12). When the determination unit 40 determines that the primary voltage fluctuates because the change rate Ve of the primary voltage value is equal to or greater than the predetermined threshold (step S12, YES), the determination unit 40 outputs an output command to the output unit 44. The abnormality notification unit 52 of the notification unit 50 notifies the abnormality of the primary voltage (step S13).

  When the determination unit 40 determines that the primary voltage value fluctuation speed Ve is less than the predetermined threshold and the primary voltage does not change (step S12, NO), the determination unit 40 determines the electrode current value of one electrode W. It is determined whether or not a difference of a predetermined threshold value or more has occurred between the sum Iw and the sum Ie of the electrode current values of the other electrode E (step S14). The determination unit 40 generates a difference of a predetermined threshold value or more between the sum Iw of the electrode current values of one electrode W and the sum Ie of the electrode current values of the other electrode E, and the “electrode current value difference condition” is satisfied. If it is determined (YES in step S14), the determination unit 40 determines whether the fluctuation speed Va of the electrode current value of the specific electrode has decreased by a predetermined threshold or more (step S15). When the determination unit 40 determines that the electrode current value fluctuation rate Va of the specific electrode is decreased by a predetermined threshold or more and the “electrode current value decrease condition” is satisfied (step S15, YES), the determination unit 40 determines that an abnormality has occurred in the branch circuit B that supplies power to the specific electrode (step S16). When the determination unit 40 determines that an abnormality has occurred in the branch circuit B that supplies power to the specific electrode, the determination unit 40 outputs an output command to the output unit 44 and notifies the abnormality notification of the notification unit 50. The unit 52 notifies the abnormality of the branch circuit B of the specific electrode (step S17).

  The contents of steps S14 to S16 will be specifically described. As shown in FIG. 1A, for example, when the connection terminal of the electrode W underlined in the first power supply device R1 is loosened, The determination unit 40 determines that a difference equal to or greater than a predetermined threshold has occurred between the sums Iw and Ie of the electrode current values of the first power supply device R1. Then, the determination unit 40 determines that the fluctuation speed Va of the electrode current value of the underlined electrode W has decreased by a predetermined threshold or more, and an abnormality is detected in the branch circuit B that supplies power to the underlined electrode W. Determine which occurred. Here, the “abnormality of the branch circuit B” refers to, for example, looseness of the connection terminals on the electrodes W and E side of the wiring for supplying power to the electrodes W and E, and the electrode current detector 17 (variable) Examples thereof include failure of the current collector 17a or the electrode current converter 17b), looseness of connection terminals of the wiring of these devices, connection failure, and the like.

  When the determination unit 40 determines that there is no difference greater than a predetermined threshold value between the sum Iw of the electrode current values of one electrode W and the sum Ie of the electrode current values of the other electrode E (step S14). , NO), the determination unit 40 determines whether or not a difference of a predetermined threshold value or more has occurred between the main circuit current value Ir and the sum Ie of the electrode current values of the electrode E (step S18). When the determination unit 40 determines that the “main circuit current value difference condition” is satisfied because a difference of a predetermined threshold value or more is generated between the main circuit current value Ir and the sum Ie of the electrode current values of the electrode E. (Step S18, YES), the determination unit 40 determines that an abnormality has occurred in the main circuit A (step S19). When the determination unit 40 determines that an abnormality has occurred in the main circuit A, the determination unit 40 outputs an output command to the output unit 44, and the abnormality notification unit 52 of the notification unit 50 causes the abnormality of the main circuit A. Is notified (step S20). Here, as “abnormality of the main circuit A”, for example, a failure of the main circuit current detector 13 (current transformer 13a or main circuit current converter 13b) provided in the main circuit A, connection of wiring of these devices, or the like. Examples include loose terminals and poor connections.

  On the other hand, when the determination unit 40 determines that there is no difference equal to or greater than the predetermined threshold value between the main circuit current value Ir and the sum Ie of the electrode current values of the electrode E (NO in step S18), the determination unit 40 determines whether the fluctuation speed Vd of the main circuit voltage value has decreased by a predetermined threshold or more (step S21). When the determination unit 40 determines that the fluctuation speed Vd of the main circuit voltage value has decreased by a predetermined threshold or more (step S21, YES), the determination unit 40 has an abnormality in the main circuit voltage detector 14. (Step S22). When the determination unit 40 determines that an abnormality has occurred in the main circuit voltage detector 14, the determination unit 40 outputs an output command to the output unit 44, and the abnormality notification unit 52 of the notification unit 50 is in the main circuit. The abnormality of the voltage detector 14 is notified (step S23). Here, examples of the “abnormality of the main circuit voltage detector 14” include failure of the transformer 14a, failure of the main circuit voltage converter 14b, looseness / connection failure of connection terminals of wiring of these devices, and the like. .

  Note that the above processing is an example, and in step S18, the determination unit 40 determines whether a difference equal to or greater than a predetermined threshold value has occurred between the main circuit current value Ir and the sum Iw of the electrode current values of the electrodes W. It may be determined that the “main circuit current value difference condition” is satisfied when a difference equal to or greater than the threshold value occurs. Further, the determination unit 40 generates a difference of a predetermined threshold value or more between the main circuit current value Ir and at least one of the W-side electrode current value sum Iw and the E-side electrode current value sum Ie. It may be judged whether or not.

  When the determination unit 40 determines that the fluctuation speed Vd of the main circuit voltage value has not decreased by a predetermined threshold or more (step S21, NO), the determination unit 40 determines that the fluctuation speed Vc of the interelectrode voltage value is equal to the predetermined threshold value. It is determined whether or not it has decreased (step S24). When the determination unit 40 determines that the fluctuation speed Vc of the interelectrode voltage value has decreased by a predetermined threshold or more (step S24, YES), the determination unit 40 has an abnormality in the interelectrode voltage detector 18. (Step S25). When the determination unit 40 determines that an abnormality has occurred in the interelectrode voltage detector 18, the determination unit 40 outputs an output command to the output unit 44, and the abnormality notification unit 52 of the notification unit 50 detects the interelectrode voltage detector. 18 abnormalities are notified (step S26). Here, examples of the “abnormality of the interelectrode voltage detector 18” include failure of the transformer 18a, failure of the interelectrode voltage converter 18b, looseness / connection failure of connection terminals of these wirings, and the like.

  When the determination unit 40 determines that the fluctuation speed Vc of the interelectrode voltage value has not decreased by a predetermined threshold value or more (step S24, NO), as illustrated in FIG. The degree of fluctuation of the electrode current values of the electrodes W and E of the device R1 is determined (step S27). That is, the determination unit 40 determines how much the electrode current value of the specific electrode of the first power supply device R1 varies with respect to the electrode current values of the other electrodes. Judgment of the fluctuation state of the electrode current values of the plurality of electrodes W and E by the determination unit 40 is performed by determining the maximum fluctuation speed Vmax among the fluctuation speeds Va of the electrode current values of all the electrodes W and E of the first power supply device R1. And the fluctuation speed difference ΔV (Vmax−Vave) of the fluctuation speed Va of the electrode current values of the electrodes W and E other than the electrode having the maximum fluctuation speed is equal to or larger than the predetermined fluctuation speed difference. It is determined whether or not the variation degree is large or small depending on whether or not there is.

  When the determination unit 40 determines that the degree of variation in the electrode current values of the plurality of electrodes W and E is large (step S27, L), the determination unit 40 selects any one of the plurality of electrode pairs 3. It is determined whether the fluctuation speed Va of the electrode current value of the specific electrode has decreased by a predetermined threshold value or more (step S28). When the determination unit 40 determines that the “electrode current value decrease condition” is satisfied because the fluctuation speed Va of the electrode current value of any one specific electrode of the plurality of electrode pairs 3 decreases by a predetermined threshold value or more. (Step S28, YES), that is, when it is determined that the electrode current value of the specific electrode is changing rapidly, the determination unit 40 determines the electrode of the other electrode of the electrode pair 3 to which the specific electrode belongs. It is determined whether the fluctuation speed Va of the current value is decreasing (step S29).

  When the determination unit 40 determines that the fluctuation rate Va of the electrode current value of the other electrode is decreasing (step S29, YES), the determination unit 40 determines that the fluctuation rate Vb of the main circuit current value is a predetermined threshold value. It is determined whether or not it has decreased (step S30). If the determination unit 40 determines that the “main circuit current value decrease condition” is satisfied because the fluctuation speed Vb of the main circuit current value decreases by a predetermined threshold value or more (step S30, YES), the determination unit 40 Then, it is determined whether the fluctuation speed Vc of the inter-electrode voltage value of the electrode pair 3 to which the specific electrode belongs has increased by a predetermined threshold or more (step S31).

  When the determination unit 40 determines that the “interelectrode voltage value increase condition” is satisfied because the fluctuation speed Vc of the interelectrode voltage value of the electrode pair 3 to which the specific electrode belongs increases by a predetermined threshold value or more (step S <b> 40). (S31, YES), the determination unit 40 determines whether or not the cooling water change temperature ΔT for cooling the specific electrode has increased by a predetermined threshold value or more (step S32). When the determination unit 40 determines that the “cooling water temperature increase condition” is satisfied because the cooling water change temperature ΔT for cooling the specific electrode increases by a predetermined threshold or more (step S32, YES), the determination unit No. 40 determines that rapid wear in a short period of time (hereinafter abbreviated as short-term wear of electrodes) has occurred in a specific electrode (step S33). When the determination unit 40 determines that the short-term wear of the specific electrode has occurred, the determination unit 40 outputs an output command to the output unit 44, and the abnormality notification unit 52 of the notification unit 50 detects the specific electrode. The short-term wear is notified (step S34).

  The contents of steps S27 to S33 will be described in detail. As shown in FIG. 1A, for example, when the short-term wear of the electrode W underlined in the first power supply device R1 occurs, the determination unit No. 40 determines that the degree of variation in the electrode current value of the underlined electrode W is large. Then, the determination unit 40 determines that the fluctuation speed Va of the electrode current value of the underlined electrode W has decreased by a predetermined threshold or more, and the underlined electrode E of the electrode E paired with the underlined electrode W It is determined that the fluctuation speed Va of the electrode current value is decreasing. Then, the determination unit 40 determines that the fluctuation speed Vb of the main circuit current value of the first power supply device R1 has decreased by a predetermined threshold value or more, and determines the inter-electrode voltage of the electrode pair 3 to which the underlined electrode W belongs. It is determined that the fluctuation speed Vc has risen above a predetermined threshold. Further, the determination unit 40 determines that the cooling water change temperature ΔT of the underlined electrode W has risen above a predetermined threshold, and determines that short-term wear of the underlined electrode W has occurred. .

  When the determination unit 40 determines that the variation in the electrode current values of the plurality of electrodes W and E is small (steps S27 and S), the determination unit 40 selects any one of the plurality of electrode pairs 3. It is determined whether the fluctuation speed Va of the electrode current value of the specific electrode has decreased by a predetermined threshold or more (step S35). When the determination unit 40 determines that the fluctuation speed Va of the electrode current value of any one specific electrode of the plurality of electrode pairs 3 has decreased by a predetermined threshold or more (step S35, YES), that is, the specific When it is determined that the electrode current value of the electrode of the second electrode is gradually changing, the determination unit 40 determines whether or not the cooling water change temperature ΔT for cooling the specific electrode is increased by a predetermined threshold value or more (step S36). . When the determination unit 40 determines that the “cooling water temperature increase condition” is satisfied by increasing the cooling water change temperature ΔT for cooling the specific electrode by a predetermined threshold or more (step S36, YES), the determination unit No. 40 determines that moderate wear over a long period of time (hereinafter abbreviated as long-term wear of the electrode) has occurred in a specific electrode (step S37). When the determination unit 40 determines that long-term wear of a specific electrode has occurred, the determination unit 40 outputs an output command to the output unit 44, and the abnormality notification unit 52 of the notification unit 50 causes the specific electrode to be output. Is notified of long-term wear (step S38).

  The contents of steps S27, S35 to S37 will be described in detail. As shown in FIG. 1A, for example, when long-term wear of the electrode W underlined in the first power supply device R1 occurs, The determination unit 40 determines that the degree of variation in the electrode current value of the underlined electrode W is small. Then, the determination unit 40 determines that the fluctuation speed Va of the electrode current value of the underlined electrode W has decreased by a predetermined threshold value or more. Further, the determination unit 40 determines that the cooling water change temperature ΔT of the underlined electrode W has risen above a predetermined threshold, and determines that long-term wear of the underlined electrode W has occurred. .

  As described above, the determination unit 40 executes the electric melting furnace abnormality determination control, so that the wear of the electrodes W and E can be determined with high accuracy, and an abnormality occurring in the electric melting furnace 100 is detected. It is possible to accurately determine whether the wear is an abnormality other than the wear of the electrodes W and E. Thereby, it is possible to easily identify the location where the abnormality occurs in the electric melting furnace 100, and to reduce the work load of the operator who performs the inspection work of the electric melting furnace 100. Inspection work and the like can be performed quickly. As a result, when an abnormality occurs in the electric melting furnace 100, the recovery time until the electric melting furnace 100 is restarted is shortened, so that the production of the molten glass G and the glass article such as a glass fiber bundle formed by molding the molten glass G Manufacturing can be performed efficiently and at low cost. In the electric melting furnace abnormality determination control according to the present embodiment, the determination unit 40 considers the fluctuation state of the electrode current values of the plurality of electrodes W and E, and determines the abnormality of individual devices of the electric melting furnace 100 as a plurality. The judgment is made based on different condition judgments. As a result, the determination unit 40 can specifically determine how the electrodes W and E are specifically worn out, and specifically identify the location where the electric melting furnace 100 is abnormal. be able to. As a result, it is possible to easily grasp the wear state of the electrodes W and E, and it is possible to more easily identify the location where the abnormality occurs in the electric melting furnace 100.

[Data analysis results]
Based on FIGS. 7-10, the data analysis result used as the basis of the setting of various conditions used in the electric melting furnace abnormality determination control and various threshold values is demonstrated. 7 to 10 show the results of analysis by the inventor of data when various abnormalities occur during actual electric melting furnace operation.

  FIG. 7 is a graph showing a change in the electrode current value for each electrode when the connection terminal of the specific electrode is loosened during the actual operation of the electric melting furnace. As shown in FIG. 7, when the connection terminal of the specific electrode W3 is loosened, the electrode of the electrode W3 in which the connection terminal is loosened with respect to the electrode current values of the other electrodes W1, W2, E1, E2, and E3. It can be seen that only the current value drops sharply in a few minutes between times t7 and t8. And although illustration is abbreviate | omitted, after the electrode current value of the electrode W3 falls rapidly from the data analysis by this inventor, the sum Iw of the electrode current value of one electrode W1-W3 of the some electrode pair 3, It has been found that there is a difference of a predetermined value or more with the sum Ie of the electrode current values of the other electrodes E1 to E3 of the plurality of electrode pairs 3. From these data analysis results, the condition determination shown in steps S14 and S15 in FIG. 5 is adopted, and the abnormality of the branch circuit B that supplies power to the electrodes W and E can be accurately determined. Note that the predetermined threshold value used for the condition determination in steps S14 and S15 in FIG. 5 is also set by the inventor from the data shown in FIG.

  FIG. 8 is data showing various detected values when a specific electrode is worn for a short period during actual electric melting furnace operation. (A) Electrode current value of each electrode on the W side, (b) Electrode current value of each electrode on the E side, (c) Main circuit current value, (d) Interelectrode voltage value of each electrode pair, (e) Each It is a graph which shows each change of the cooling water temperature of an electrode. As shown in FIG. 8 (a), when short-term wear occurs on a specific electrode W1 on the W side, the electrode current values of the other electrodes W2 and W3 on the W side increase while short-term wear occurs. It can be seen that only the electrode current value of the electrode W1 rapidly decreases. Then, as shown in FIG. 8 (b), it can be seen that the electrode current value of the other electrode E1 of the electrode pair 3 to which the electrode W1 that has been worn for a short period of time falls rapidly decreases, as shown in FIG. 8 (c). Thus, it can be seen that the main circuit current value of the power supply device also decreases. Further, as shown in FIG. 8 (d), it can be seen that the inter-electrode voltage value V1 of the electrode pair 3 to which the electrode W1 that has been worn for a short period of time rapidly increases, as shown in FIG. 8 (e), It can be seen that the cooling water temperature T1 of the electrode W1 that has been worn out for a short period of time is rapidly increasing. From these data analysis results, the condition determination shown in steps S28, S29, S30, S31, and S32 of FIG. 6 is adopted, and the short-term wear of the electrodes W and E can be accurately determined. Further, the predetermined threshold values used for the condition determination in S28, S29, S30, S31, and S32 in FIG. 6 are also set by the present inventor from the data shown in FIG. In the data shown in FIG. 8, the electrode current value, the main circuit current value, and the inter-electrode voltage value changed due to short-term wear of the electrode W1 are recovered over time in the control system of the electric melting furnace 100. This is because the above-described constant power control is performed.

  FIG. 9 is a graph showing changes in the electrode current value for each electrode when short-term wear of a specific electrode occurs during actual electric melting furnace operation. Moreover, FIG. 10 is a graph which shows the change of the electrode electric current value for every electrode when long-term wear of a specific electrode has arisen during actual electric melting furnace operation.

  As shown in FIG. 9, when short-term wear occurs on a specific electrode W5 on the W side, the electrode current values of the other electrodes W1, W2, W3, W4, and W6 on the W side increase, but in a short period of time. It can be seen that only the electrode current value of the electrode W5 where the wear has occurred rapidly decreases. And although illustration is abbreviate | omitted, when the standard deviation of the electrode current value of the electrodes W1-W6 is calculated every time t1-t8 from the data analysis by this inventor, the time t3-t5 when the electrode W5 was worn out for a short period of time It was found that the standard deviation increased rapidly in the few minutes between. Further, when the standard deviation of the electrode current values at the times t1 to t8 is calculated for each of the electrodes W1 to W6, the standard deviation of the electrode W5 that has been worn for a short period of time is the other electrode W1, W2, W3, W4, W6 on the W side. It was found to increase more rapidly than the standard deviation.

  As shown in FIG. 10, when the specific electrode W1 on the W side is worn for a long time, the electrode current values of the other electrodes W2, W3, W4, W5, and W6 on the W side hardly change. It can be seen that only the electrode current value of the electrode W1 where the period wear has occurred gradually decreases. And although illustration is abbreviate | omitted, when the standard deviation of the electrode current value of the electrodes W1-W6 is calculated every time t1-t8 from the data analysis by this inventor, time t2-t5 when the electrode W1 was worn out for a long period of time It was found that the standard deviation gradually increased in the hours between.

  From these data analysis results of FIG. 9 and FIG. 10, the maximum fluctuation speed Vmax among the fluctuation speeds Va of the electrode current values of the plurality of electrodes W and E, and the other electrode W other than the electrode having the maximum fluctuation speed. , E electrode current value fluctuation speed Va and average fluctuation speed Vave from the fluctuation speed difference ΔV, that is, due to the fluctuation state of the electrode current values of the plurality of electrodes W, E, whether or not a specific electrode has worn for a short period of time? It was found that it was possible to determine whether long-term wear occurred. Then, the condition determination shown in step S27 of FIG. 6 is adopted, and it has become possible to accurately determine whether a specific electrode has been worn for a short period or has been worn for a long time. The predetermined fluctuation speed difference used for the condition determination in step S27 in FIG. 6 is also set by the present inventor from the data shown in FIGS.

  In the present embodiment, the data analysis results used as the basis for setting various conditions and various threshold values used in the electric melting furnace abnormality determination control are shown as examples in FIGS. 7 to 10. As for various conditions and threshold values used in the electric melting furnace abnormality determination control other than those shown in the example of the above, the inventor correlates the data from the data during actual electric melting furnace operation over several years. This is a detailed analysis and setting of conditions.

[Another embodiment]
(1) In the above-described embodiment, the example in which the determination unit 40 is configured to determine abnormality of individual devices of the electric melting furnace 100 by a plurality of different condition determinations has been described. However, as a simple determination method, the determination unit 40 However, it may be configured to determine only that the abnormality of the individual apparatus is an abnormality of the electric melting furnace 100 other than the wear of the electrodes W and E (not the wear of the electrodes W and E) without judging the conditions. Good. Specifically, for example, all the steps S12 to S26 are omitted, and the determination unit 40 does not determine that the electrodes W and E are worn out after step S27 (for example, NO in steps S28 to S32, S35, and S36). In branching), the determination unit 40 determines that an abnormality of the electric melting furnace 100 other than the wear of the electrodes W and E has occurred, and the determination unit 40 outputs an output command to the output unit 44 to notify the abnormality of the notification unit 50. The part 52 may be configured to notify the abnormality of the electric melting furnace 100 other than the wear of the electrodes W and E. In short, if the determination unit 40 can accurately determine the wear of the electrodes W and E, the abnormality occurring in the electric melting furnace 100 is the wear of the electrodes W and E or an abnormality other than the wear of the electrodes W and E. Moreover, the object of the present invention can be achieved even if the determination can be made accurately and the abnormality of the individual equipment of the electric melting furnace 100 cannot be determined.

(2) Contrary to the above (1), the determination unit 40 is configured to determine only the wear of the electrodes W and E without judging the detailed abnormality of the wear of the electrodes W and E without judging the condition. Also good. Specifically, for example, all steps after step S27 are omitted, and the determination unit 40 determines that the fluctuation speed Vc of the interelectrode voltage value has not decreased by a predetermined threshold or more (NO branch of step S24). The determination unit 40 determines that wear of the electrodes W and E has occurred, the determination unit 40 outputs an output command to the output unit 44, and the abnormality notification unit 52 of the notification unit 50 causes the wear of the electrodes W and E to be worn. You may comprise so that abnormality may be alert | reported. In short, if the determination unit 40 can accurately determine whether the abnormality occurring in the electric melting furnace 100 is the wear of the electrodes W and E or the abnormality other than the wear of the electrodes W and E, The wear can also be determined with high accuracy, and the object of the present invention can be achieved even if detailed abnormalities of the electrode wear W and E cannot be determined.

(3) Not limited to the examples described in the above (1) and (2), as long as the object of the present invention can be achieved, a part of the condition determination in the flowcharts of FIGS. Naturally, it is possible to change the order of the condition judgment in the flowcharts of FIGS. Specifically, for example, any one or more of steps S12, S14, S15, S18, S21, and S24 in FIG. 5 may be omitted, and any one of steps S28 to S32, S35, and S36 in FIG. The above may be omitted. Further, for example, the order of steps S12, S14, S18, S21, and S24 in FIG. 5 may be changed, the order of steps S28 to S32 in FIG. 6 may be changed, and the order of steps S35 and S36 in FIG. May be changed.

(4) In the above embodiment, the electric melting furnace abnormality determination control using the electrode current value detected by the electrode current detector 17 or the interelectrode voltage value detected by the interelectrode voltage detector 18 as power information of the branch circuit B Although the example used for the determination is shown, the resistance value and the power value calculated from these detection values may be used as the power information of the branch circuit B for the determination of the electric melting furnace abnormality determination control. Further, the main circuit current value detected by the main circuit current detector 13 and the main circuit voltage value detected by the main circuit voltage detector 14 are used as power information of the main circuit A for the determination of the electric melting furnace abnormality determination control. However, the resistance value and the power value calculated from these detection values may be used as the power information of the main circuit A for the determination of the electric melting furnace abnormality determination control.

(5) In the above embodiment, the example in which the fluctuation speeds Va, Vb, Vc, Vd, Ve and the cooling water change temperature ΔT calculated in the input processing unit 31 are used for the determination of the electric melting furnace abnormality determination control is shown. The predetermined time data D and the average value Da used for these calculations may be used for determination in the electric melting furnace abnormality determination control. Moreover, you may comprise so that the collection data collected in every 1st predetermined time ta in the input process part 31 may be used for determination of electric melting furnace abnormality determination control as it is. Further, for the calculation of the sum Iw and Ie of the electrode current values and the main circuit current value Ir, the data adopted as the predetermined time data D is not used, but the average value Da or the input processing unit 31 uses the first predetermined time ta. Data collected every time may be used. In this case, the predetermined threshold used for various determinations in the electric melting furnace abnormality determination control may be appropriately set in the initial condition setting unit 41 according to the type of data used for the determination.

(6) In the above embodiment, an example is shown in which the electric melting furnace abnormality determination control is determined based on whether or not the fluctuation speeds Va, Vb, Vc, Vd, Ve and the cooling water change temperature ΔT have changed by a predetermined threshold value or more. However, if it is determined whether or not the detected value or the calculated value has changed by a predetermined value or more, the determination may be made with a different reference value. Specifically, for example, when the predetermined time data D, the average value Da, and the collected data are used in the determination of the electric furnace abnormality determination control in the above (5), the predetermined time data D and the average value Da are used. Alternatively, the electric melting furnace abnormality determination control may be determined based on whether or not the collected data is below or above a preset threshold value.

(7) In the above embodiment, when the determination unit 40 determines the wear (short-term wear and long-term wear) of the electrodes W and E, the determination unit 40 outputs an output command to the output unit 44 and the notification unit 50. Although the example in which the abnormality notifying unit 52 is configured to notify the wear of the electrodes W and E has been shown, it may be configured as follows. That is, when the determination unit 40 determines the wear of the electrodes W and E, the determination unit 40 outputs to the above-described electrode moving means via the output unit 44, and the electrode determined to be worn is the predetermined length of the melting furnace 2. It may be configured to move the electrode into the melting furnace 2 and maintain the protruding length into the melting furnace 2 at a constant length.

(8) In the above embodiment, the example in which the electric melting furnace 100 includes the three power supply apparatuses, the first to third power supply apparatuses R1 to R3, is shown. However, the electric melting furnace 100 is a single power supply apparatus. The electric melting furnace 100 may employ | adopt the structure provided with 2 or 4 or more electric power supply apparatuses.

(9) In the above embodiment, the first power supply device R1 heats the region closer to the insertion port 1, and the second and third power supply devices R2, R3 heat the region closer to the throat 4. However, if the first to third power supply devices R1 to R3 can be distinguished from each other on the electric circuit, the first to third power supply devices R1 to R3 are not used to divide and heat the region. For example, the electrode pairs 3 belonging to the respective power supply devices are regularly and alternately arranged in the melting furnace, for example, the electrode pairs 3 belonging to the respective power supply devices are irregularly arranged in the melting furnace. It may be provided.

(10) In the above embodiment, an example in which the three electrode pairs 3 are arranged in one power supply device has been described. However, if the configuration includes the branch circuit B branched from the main circuit A, one power supply is provided. Two or four or more electrode pairs 3 may be provided in the apparatus.

(11) In the above-described embodiment, the example in which the various devices of the power supply system of the electric melting furnace 100 are configured with the AC specifications corresponding to the AC two-phase power source has been described. May be configured with an AC specification corresponding to an AC three-phase power source. Further, various devices (electrodes and the like) in the power supply system of the electric melting furnace 100 may be configured with a DC specification corresponding to a DC power source. Moreover, you may comprise so that alternating current power supply may be converted into direct current | flow with a converter and supplied to various apparatuses (electrode etc.) of a direct current specification. Even in these cases, the number of electrodes arranged in one power supply device can be set as appropriate if the configuration has the branch circuit B branched from the main circuit A.

  The electric melting furnace control system of the present invention is not limited to an electric melting furnace control system for melting glass as an object to be heated, but different objects to be heated such as steel, aluminum and other metal materials, synthetic resins and other resin materials. It can also be used for a control system of an electric melting furnace that melts.

2 Melting furnace 3 Electrode pair 6 Cooling device 7 Temperature detector (temperature detection means)
13 Main circuit current detector (main circuit detection means)
14 Main circuit voltage detector (main circuit detection means)
17 Electrode current detector (branch circuit detection means)
18 Electrode voltage detector (detection means for branch circuit)
30 Controller 34 Current Value Calculation Unit (Current Value Calculation Means)
40 determination unit 100 electric melting furnace G molten glass (object to be heated)
W electrode E electrode R1 first power supply device R2 second power supply device R3 third power supply device

Claims (10)

An electric melting furnace for heating an object to be heated in a melting furnace by distributing and supplying electric power through a branch circuit branched from a main circuit to each of a plurality of electrodes arranged as a plurality of electrode pairs in the melting furnace. A control system,
A control device for controlling the electric melting furnace, a branch circuit detection means for detecting power information of the branch circuit, and a main circuit detection means for detecting power information of the main circuit,
The control device includes a determination unit that determines wear of the electrode based on power information of the branch circuit and power information of the main circuit ,
The branch circuit detection means includes electrode current detection means for detecting the electrode current value of the branch circuit, and the main circuit current detection means for detecting the main circuit current value of the main circuit as the main circuit detection means. With
The determination unit is configured to determine wear of the electrode based on the electrode current value and the main circuit current value;
The determination unit reduces the electrode current value of one specific electrode of the plurality of electrode pairs by a predetermined value or more to satisfy a specific electrode current value decrease condition, and reduces the main circuit current value by a predetermined value or more. An electric melting furnace control system configured to determine that the specific electrode is worn out when a main circuit current value lowering condition is satisfied . The determination unit satisfies the specific electrode current value lowering condition and the main circuit current value lowering condition, and further the electrode current value of the counter electrode paired with the specific electrode is decreased by a predetermined value or more to decrease the counter electrode current value. 2. The electric melting furnace control system according to claim 1 , wherein when the condition is satisfied, the specific electrode is determined to be worn out. As the branch circuit detection means, an interelectrode voltage detection means for detecting an interelectrode voltage value between the branch circuits supplying power to the electrode pair,
If the inter-electrode voltage value of any one of the plurality of electrode pairs rises by a predetermined value or more and the inter-electrode voltage value increase condition is satisfied, the determination unit belongs to the specific electrode pair The control system for an electric melting furnace according to claim 1 or 2 , wherein the control system is configured to determine that the electrode is worn out. An electric melting furnace for heating an object to be heated in a melting furnace by distributing and supplying electric power through a branch circuit branched from a main circuit to each of a plurality of electrodes arranged as a plurality of electrode pairs in the melting furnace. A control system,
A control device for controlling the electric melting furnace, a branch circuit detection means for detecting power information of the branch circuit, and a main circuit detection means for detecting power information of the main circuit,
The control device includes a determination unit that determines wear of the electrode based on power information of the branch circuit and power information of the main circuit,
Furthermore, a temperature detecting means for detecting a cooling water temperature of cooling water for cooling the melting furnace insertion portion of the electrode,
When the cooling water temperature for cooling the melting furnace insertion part of the specific electrode of any one of the plurality of electrodes rises by a predetermined value or more and the cooling water temperature increase condition is satisfied, the specific electrode There control system configured has that electric melting furnace to determine that the wear. An electric melting furnace for heating an object to be heated in a melting furnace by distributing and supplying electric power through a branch circuit branched from a main circuit to each of a plurality of electrodes arranged as a plurality of electrode pairs in the melting furnace. A control system,
A control device for controlling the electric melting furnace, a branch circuit detection means for detecting power information of the branch circuit, and a main circuit detection means for detecting power information of the main circuit,
The control device includes a determination unit that determines wear of the electrode based on power information of the branch circuit and power information of the main circuit,
The branch circuit detection means includes an electrode current detection means for detecting an electrode current value of the branch circuit, and further includes a current value calculation means for calculating the electrode current value,
The determination unit is configured to determine wear of the electrode based on a calculation result of the current value calculation unit,
The current value calculation means calculates a sum of electrode current values of one electrode of each of the plurality of electrode pairs and a sum of electrode current values of the other electrode of the plurality of electrode pairs,
The determination unit determines wear of the electrode on the condition that a difference greater than a predetermined value does not occur between the sum of the electrode current values of the one electrode and the sum of the electrode current values of the other electrode. control system configuration is not that electric melting furnace so. The determination unit generates a difference greater than or equal to a predetermined value between the sum of the electrode current values of the one electrode and the sum of the electrode current values of the other electrode, and satisfies the electrode current value difference condition, If the electrode current value of any one specific electrode of the electrode pair decreases by a predetermined value or more and the specific electrode current value decrease condition is satisfied, an abnormality has occurred in the branch circuit that supplies power to the specific electrode The control system for an electric melting furnace according to claim 5 , wherein the control system is configured to make a determination. The main circuit detection means includes main circuit current detection means for detecting a main circuit current value of the main circuit,
The current value calculation means calculates a sum of electrode current values of one electrode of each of the plurality of electrode pairs or a sum of electrode current values of the other electrode of the plurality of electrode pairs,
The determination unit determines the wear of the electrode on the condition that there is no difference more than a predetermined value between the main circuit current value and the sum of the electrode current values of the one or the other electrode. The control system of the electric melting furnace of Claim 5 or 6 comprised . When the main circuit current value difference condition is satisfied when the determination unit generates a difference of a predetermined value or more between the main circuit current value and the sum of the electrode current values of the one or the other electrode, the main circuit current value difference condition is satisfied. The control system for an electric melting furnace according to claim 7 , wherein the control system is configured to determine that an abnormality has occurred in the circuit. The electric melting furnace includes a plurality of power supply devices that supply power to the plurality of electrodes from the main circuit via a branch circuit,
The branch circuit detecting means is configured to detect power information of each branch circuit of the plurality of power supply devices, and the main circuit detection means is configured to detect each main circuit of the plurality of power supply devices. It is configured to detect power information, further, the determination unit, the more claims that are configured to determine the wear of the electrode in the power supply device of each of the power supply device 1, 4 or 5 Control system for electric melting furnace as described in 1. The glass manufacturing method which manufactures molten glass using the control system of the electric melting furnace as described in any one of Claims 1-9 .

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