CN111473641A - Electric arc furnace temperature control method for fused magnesia production - Google Patents
Electric arc furnace temperature control method for fused magnesia production Download PDFInfo
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- CN111473641A CN111473641A CN202010325924.4A CN202010325924A CN111473641A CN 111473641 A CN111473641 A CN 111473641A CN 202010325924 A CN202010325924 A CN 202010325924A CN 111473641 A CN111473641 A CN 111473641A
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- electric arc
- arc furnace
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
- F27B3/10—Details, accessories, or equipment peculiar to hearth-type furnaces
- F27B3/28—Arrangement of controlling, monitoring, alarm or the like devices
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2/00—Lime, magnesia or dolomite
- C04B2/10—Preheating, burning calcining or cooling
- C04B2/102—Preheating, burning calcining or cooling of magnesia, e.g. dead burning
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces
- F27B3/08—Hearth-type furnaces, e.g. of reverberatory type; Tank furnaces heated electrically, with or without any other source of heat
- F27B3/085—Arc furnaces
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27M—INDEXING SCHEME RELATING TO ASPECTS OF THE CHARGES OR FURNACES, KILNS, OVENS OR RETORTS
- F27M2003/00—Type of treatment of the charge
- F27M2003/13—Smelting
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
Abstract
The invention relates to the technical field of temperature control, in particular to a temperature control method of an electric arc furnace for producing electric melting magnesia, which is characterized in that three electrodes in the electric arc furnace are arranged at the bottom of the electric arc furnace, the three electrodes are hung at the bottom of a lifting arm, a lifting hydraulic cylinder is respectively arranged between the lifting arm and each electrode, a temperature sensor is arranged outside the furnace body of the electric arc furnace according to a matrix, a split structure is formed between a base of the electric arc furnace and the furnace body, the base of the electric arc furnace and the furnace body are connected through a plurality of groups of sliding clamps, so that the base of the electric arc furnace can rotate relative to the furnace body, a base rotating mechanism is connected at. Compared with the prior art, the invention has the advantages that: when a certain area in the furnace is overheated, the height and the distribution of the three electrodes can be respectively adjusted and controlled by combining two driving mechanisms of the electrode lifting arm and the base rotating mechanism, so that the uniformity of a temperature field of an arc zone in the furnace is realized, and the integral smelting efficiency is improved.
Description
Technical Field
The invention relates to the technical field of temperature control, in particular to a temperature control method of an electric arc furnace for producing fused magnesia.
Background
The electric arc furnace smelting is a working mode of low voltage and large current, electric energy is injected into a graphite electrode, electric arcs are generated between the electrode and materials, the temperature of an arc area is more than 3000 ℃, and magnesite or high-purity magnesite can be melted and purified. The electric arc furnace mainly comprises an electric arc furnace transformer, a graphite electrode, a lifting arm, a movable furnace body, a variable frequency motor, a control system and the like. The three graphite electrodes are respectively fixed on the lifting arm and driven by positive and negative rotation of the variable frequency motor to adjust the distance between the graphite electrodes and the ore, so that the control of the discharge process is realized, and the balance of three-phase current is kept.
In the magnesite industry, fused magnesite is prepared by melting high-quality magnesite serving as a raw material. The magnesia fired by using natural magnesite as a raw material is called as sintered magnesia; magnesite, sintered magnesite and the like are used as raw materials and are smelted by an electric arc furnace to reach a molten state and cooled to form the fused magnesite. The fused magnesia has high purity, large crystal grains, compact structure, strong slag resistance and good thermal shock stability, is an excellent high-temperature electrical insulating material, and is also an important raw material for manufacturing high-grade magnesia bricks, magnesia carbon bricks and unshaped refractory materials.
The patent application number is 201821101362. X's chinese utility model patent discloses a device of electric arc-induction smelting fused magnesia, including furnace body, three-phase electrode, electromagnetic induction coil, inner liner, the three-phase electrode setting is inside the furnace body, and the furnace body inner wall is equipped with the inner liner, and electromagnetic induction coil arranges in the inner liner outside, and the inner film body is arranged in the inner liner inboard, and the coating has the refractory asbestos layer between inner liner and the electromagnetic induction coil. The magnesium inner liner is arranged in the device, so that the safety coefficient of the device in the production process is improved, the safety of field operators is guaranteed, and a good operation environment is maintained; the lining layer and the electromagnetic induction coil enable the equipment to form an effective heat storage space in the furnace body in the production process.
In the prior art, the quality of fused magnesia is improved by taking lifting graphite electrodes and increasing the heat preservation condition of a furnace body as means, but in the smelting process of an electric arc furnace, the phenomenon of local overheating often occurs due to uneven ore distribution, so that the temperature in the furnace is uneven, uniform smelting reaction cannot be realized, the service life of the furnace body is influenced by the local overheating of the furnace body, in addition, the current is unbalanced, the safe work and the power saving target of the electric arc furnace are also influenced, and how to control the temperature in the furnace becomes a technical problem to be solved urgently by technical personnel in the field.
Disclosure of Invention
The invention aims to provide a temperature control method of an electric arc furnace for producing fused magnesia, which overcomes the defects of the prior art, and can control the heights and the directions of three electrodes by combining an electrode lifting arm and a base rotating mechanism when a certain area in the furnace is overheated according to matrix temperature detection data and a rotary electric arc furnace base, thereby realizing the uniform temperature field of an arc area in the furnace, improving the integral smelting efficiency, protecting the furnace body of the electric arc furnace, avoiding abnormal burning loss and prolonging the service life.
In order to achieve the purpose, the invention adopts the technical scheme that:
the temperature control method of the electric arc furnace for producing the fused magnesia is characterized in that three electrodes in the electric arc furnace are arranged at the bottom of the electric arc furnace, the three electrodes are hung at the bottom of a lifting arm, a lifting hydraulic cylinder is arranged between the lifting arm and each electrode, and the top of the lifting arm is connected with a worm gear lifter; the process parameters of the electric arc furnace are as follows: the secondary working voltage is 50-60V, the secondary working current is 3000-5500 amperes, the electrode is a graphitized electrode with the diameter of 280mm, and the center distance of the three-phase electrode is 600 mm; the utility model discloses an electric arc furnace, including electric arc furnace base, furnace body, base rotary mechanism, servo motor, electric arc furnace base, base rotary mechanism, temperature sensor is provided with according to the matrix in the furnace body outside of electric arc furnace, is the components of a whole that can function independently structure between electric arc furnace base and the furnace body, is connected through multiunit slip anchor clamps between electric arc furnace base and the furnace body, makes electric arc furnace base furnace body relatively rotate, the bottom of electric.
The temperature sensor is equipped with 9 ~36 in a matrix, the matrix sets up according to 8 equalling, 12 equalling or 16 equalling along the furnace body circumference, and furnace body outside matrix is equipped with 2~3 layers from top to bottom.
The base rotating mechanism is a gear transmission mechanism or a chain wheel transmission mechanism.
The sliding fixture comprises a fixed seat and a pulley, the upper end of the C-shaped fixed seat is connected with the pulley through a pin shaft, the lower end of the C-shaped fixed seat is fixedly connected with the base of the electric arc furnace, and the pulley can roll along a groove in a flange on the outer side of the furnace body.
The temperature sensor is connected with a P L C input module through a multi-channel signal collector, a P L C calculates the average temperature of each matrix in the same circumference according to temperature measurement values, when the temperature value of a certain matrix exceeds the temperature value of other matrices by 15%, the area is determined to be overheated, a P L C instructs a base rotating mechanism to rotate by an index according to the index value of the matrix, and when no matrix area is overheated in the melting time set by a program, the melting is finished according to the time set by the program.
The temperature sensor is connected with a P L C input module through a multi-channel signal collector, a P L C calculates the temperature average value of each matrix in the same column according to the temperature measurement value, when the temperature average value of a certain matrix exceeds the temperature value of other matrices by 15%, the area is determined to be overheated, the P L C instructs the lifting hydraulic cylinder to lift or descend by one layer of graduation, and when no matrix area is overheated in the melting time set by a program, the melting is finished according to the time set by the program.
The values of the temperature measurements that exceed the theoretical temperature value by 50% are removed before the average value is calculated by P L C to avoid the effect of sensor failure on the calculated values.
Compared with the prior art, the invention has the beneficial effects that: 1 according to matrix temperature detection data and rotation type electric arc furnace base, when certain region appears overheated in the stove, can combine two kinds of actuating mechanism of electrode lifing arm and base rotary mechanism, the height and the interior position distribution of circumference of the three electrode of regulation control respectively to the temperature field in the realization stove arc district is even, improves the efficiency of whole smelting. 2) The method has the advantages of protecting the body of the electric arc furnace, avoiding abnormal burning loss caused by overhigh local temperature and prolonging the service life of the electric arc furnace, along with wide applicability and popularization value, and can be used for electric arc furnaces in other application occasions.
Drawings
FIG. 1 is a schematic structural view of an electric arc furnace according to an embodiment of the present invention.
Fig. 2 is a schematic structural view of an embodiment of the slide clamp of the present invention.
FIG. 3 is a schematic diagram of a P L C control system according to an embodiment of the present invention.
FIG. 4 is a schematic diagram of the structure of a multi-channel data collector in the control system of the present invention.
In the figure: 1-furnace frame, 2-furnace cover, 3-electric arc furnace base, 4-furnace body, 5-electrode, 6-lifting arm, 7-lifting hydraulic cylinder, 8-worm gear lifter, 9-temperature sensor, 10-sliding clamp, 11-base rotating mechanism, 12-fixed seat, 13-pulley, 14-pin shaft, 15-flange and 16-matrix.
Detailed Description
The following further describes the embodiments of the present invention with reference to the drawings.
Referring to fig. 1-2, the structure of the electric arc furnace for producing fused magnesite according to the embodiment of the invention is schematically illustrated, and the electric arc furnace comprises a furnace frame 1, a furnace cover 2, an electric arc furnace base 3 and a furnace body 4, wherein three electrodes 5 in the electric arc furnace are hung at the bottom of a lifting arm 6, the three electrodes 5 are hung at the bottom of the electric arc furnace, a lifting hydraulic cylinder 7 is respectively arranged between the lifting arm 6 and each electrode 5, the top of the lifting arm 6 is connected with a worm and gear lifter 8, the worm and gear lifter 8 realizes the lifting of the lifting arm 6 and can control the simultaneous lifting of the three electrodes, and the lifting hydraulic cylinder 7 is used for controlling the independent lifting of. The process parameters of the electric arc furnace are as follows: the secondary working voltage is 50-60V, the secondary working current is 3000-5500 amperes, the electrode is a graphitized electrode with the diameter of 280mm, and the center distance of the three-phase electrode is 600 mm; the outside of the furnace body 4 of the electric arc furnace is provided with a temperature sensor 9 according to a matrix, a split structure is arranged between the electric arc furnace base 3 and the furnace body 4, the electric arc furnace base 3 and the furnace body 4 are connected through a plurality of groups of sliding clamps 10, the electric arc furnace base 3 can rotate relative to the furnace body 4, the bottom of the electric arc furnace base 3 is connected with a base rotating mechanism 11, and a servo motor is arranged in the base rotating mechanism 11. Control of the height and orientation of the three electrodes can be achieved based on temperature measurements.
The temperature sensors 9 are arranged in a matrix 16, 5 × 5=25, the diameter of the furnace body 4 is 3 meters, the size of the matrix is 785mm wide and 900mm high, the matrix 16 is equally divided along the circumference of the furnace body according to 12, and the matrix on the outer side of the furnace body is provided with 2 layers from top to bottom.
The base rotating mechanism 11 is a gear transmission mechanism, and is driven by a servo motor to rotate in an indexing way under the control of a P L C control system.
The sliding fixture 10 comprises a fixed seat 12 and a pulley 13, the upper end of the C-shaped fixed seat is connected with the pulley 13 through a pin shaft 14, the lower end of the C-shaped fixed seat is fixedly connected with the electric arc furnace base 3, and the pulley 13 can roll along a groove on a flange 15 on the outer side of the furnace body. The structure can be used for realizing the relative rotation and sealing of the electric arc furnace base 3 relative to the furnace body 4, and the overheating condition of a certain position can be avoided after the rotation.
Referring to fig. 3, the P L C control system of the invention is a schematic diagram, in the control system, a P L C is connected with a temperature sensor through a multi-channel signal collector (having the functions of signal conditioning, isolation amplification and conversion), a P L C is connected with a worm gear lifter through a lifting motor drive circuit, a P L C is connected with a servo motor through a servo motor controller, and a P L C is connected with a lifting hydraulic cylinder electromagnetic valve through a valve drive circuit.
The P L C is connected with an NB-L OT narrowband Internet of things transceiver and can be used as a terminal of an Internet of things network to realize the transmission and the reception of equipment information of the whole network, and the P L C is connected with an RS-485 interface, so that the communication of remote data is favorably realized.
And P L C collects temperature signals in each matrix partition on the surface of the furnace body, controls the opening of a motor of the worm gear lifter, a servo motor in the base rotating mechanism and a lifting hydraulic cylinder, and realizes the change of the height and the orientation of the electrode in the furnace body.
The first control mode is that the temperature sensor is connected with the P L C input module through the multi-channel signal collector, the P L C calculates the average temperature of each matrix in the same circumference according to the temperature measurement value, when the temperature value of a certain matrix exceeds the temperature value of other matrices by 15%, the area is determined to be overheated, the P L C instructs the base rotating mechanism to rotate by a graduation according to the matrix graduation value, and when no matrix area is overheated in the programmed smelting time, the smelting process is ended according to the programmed time of the electric arc furnace.
The second control mode is that the temperature sensor is connected with the P L C input module through a multi-channel signal collector, the P L C calculates the temperature average value of each matrix in the same column according to the temperature measurement value, when the temperature average value of a certain matrix exceeds the temperature value of other matrices by 15%, the area is determined to be overheated, the P L C instructs the lifting hydraulic cylinder to lift or descend by one layer of graduation, and when no matrix area is overheated in the programmed smelting time, the smelting process is finished according to the programmed time of the electric arc furnace.
To avoid the effect of sensor failure on the calculated values, P L C in the temperature measurements was averaged to remove values where the temperature exceeded the theoretical temperature value by ± 50%.
When a certain area in the furnace is overheated, the height and the direction of the three electrodes can be controlled by combining the electrode lifting arm and the base rotating mechanism, so that the uniformity of a temperature field of an arc area in the furnace is realized, the integral smelting efficiency is improved, the furnace body of the electric arc furnace is protected, the abnormal burning loss is avoided, and the service life is prolonged.
Fig. 4 is a structural schematic diagram of a multi-channel data collector in the control system of the invention, which is formed by sequentially connecting an S R signal access unit, a BH signal conversion unit, an FD amplification unit and an embedded microcomputer QW, wherein 8 channels of signals are sent to an SR signal input unit in a time-sharing manner, and then analog signals output sequentially through the BH signal conversion unit and the FD amplification unit enter the embedded microcomputer, and the embedded microcomputer is provided with a field bus interface to communicate with a measurement and control device; the SR signal access unit is connected with a data bus of the embedded microcomputer through a latch I, the BH signal conversion unit is connected with the data bus of the embedded microcomputer through a latch II, and the FD amplification unit is connected with the data bus of the embedded microcomputer through a latch III.
Each channel of the multi-channel data acquisition device can be connected with various signals, the signals can be directly connected with a sensor without using a transmitter, and the requirements of field acquisition are greatly met. The multi-channel data acquisition unit can realize the function of a field bus, has small volume, can conveniently form a network node type signal acquisition system, improves the acquisition speed and the operation speed, and is favorable for realizing the purpose of real-time control.
The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.
Claims (7)
1. The temperature control method of the electric arc furnace for producing the fused magnesia is characterized in that three electrodes in the electric arc furnace are arranged at the bottom of the electric arc furnace, the three electrodes are hung at the bottom of a lifting arm, a lifting hydraulic cylinder is arranged between the lifting arm and each electrode, and the top of the lifting arm is connected with a worm gear lifter; the process parameters of the electric arc furnace are as follows: the secondary working voltage is 50-60V, the secondary working current is 3000-5500 amperes, the electrode is a graphitized electrode with the diameter of 280mm, and the center distance of the three-phase electrode is 600 mm; the utility model discloses an electric arc furnace, including electric arc furnace base, furnace body, base rotary mechanism, servo motor, electric arc furnace base, base rotary mechanism, temperature sensor is provided with according to the matrix in the furnace body outside of electric arc furnace, is the components of a whole that can function independently structure between electric arc furnace base and the furnace body, is connected through multiunit slip anchor clamps between electric arc furnace base and the furnace body, makes electric arc furnace base furnace body relatively rotate, the bottom of electric.
2. The method for controlling the temperature of an electric arc furnace for producing fused magnesite according to claim 1, wherein the number of the temperature sensors is 9-36 in a matrix, the matrix is arranged along the circumference of the furnace body at 8, 12 or 16 equal parts, and the matrix at the outer side of the furnace body is provided with 2-3 layers from top to bottom.
3. The method for controlling the temperature of an electric arc furnace for producing fused magnesite according to claim 1, wherein the base rotating mechanism is a gear transmission mechanism or a sprocket transmission mechanism.
4. The method for controlling the temperature of an electric arc furnace for producing fused magnesite according to claim 1, wherein the sliding fixture comprises a fixed base and a pulley, the upper end of the C-shaped fixed base is connected with the pulley through a pin shaft, the lower end of the C-shaped fixed base is fixedly connected with the base of the electric arc furnace, and the pulley can roll along a groove on a flange on the outer side of the furnace body.
5. The method of claim 1, wherein the temperature sensor is connected to a P L C input module via a plurality of signal collectors, the P L C calculates the average temperature of the matrices within the same circumference based on the temperature measurements, and when the temperature of a matrix exceeds the temperature of other matrices by 15%, the matrix is determined to overheat, the P L C instructs the base rotating mechanism to rotate by an index according to the index, and when there is no matrix area overheat within the programmed melting time, the melting is terminated according to the programmed time.
6. The method of claim 1, wherein the temperature sensor is connected to a P L C input module via a plurality of signal collectors, the P L C calculates the average temperature values of the matrices in the same column based on the measured temperature values, and when the average temperature value of a matrix exceeds the temperature values of other matrices by 15%, the region is determined to be overheated, the P L C instructs the lifting cylinder to lift or lower by one graduation, and when no matrix region is overheated within the programmed melting time, the melting is terminated according to the programmed time.
7. A method for controlling the temperature of an electric arc furnace for fused magnesia according to claim 5 or 6, wherein the measured temperature values are obtained by removing the value of the temperature exceeding the theoretical temperature value by ± 50% before calculating the average value of P L C, so as to avoid the influence of sensor failure on the calculated value.
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| CN202010325924.4A CN111473641B (en) | 2020-04-23 | 2020-04-23 | Electric arc furnace temperature control method for fused magnesia production |
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| CN202010325924.4A CN111473641B (en) | 2020-04-23 | 2020-04-23 | Electric arc furnace temperature control method for fused magnesia production |
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| CN111473641B CN111473641B (en) | 2022-05-17 |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202153094U (en) * | 2011-06-08 | 2012-02-29 | 宝鸡铠丰科技发展有限公司 | Novel smelting electric arc furnace for fused magnesium oxide |
| CN102410727A (en) * | 2011-12-23 | 2012-04-11 | 龙南龙钇重稀土科技股份有限公司 | High-temperature smelting and reducing three-phase arc furnace |
| CN207280172U (en) * | 2017-10-18 | 2018-04-27 | 唐山首唐宝生功能材料有限公司 | Electric furnace arrangement for producing steel |
| CN110260647A (en) * | 2019-05-28 | 2019-09-20 | 江苏天楹环保能源成套设备有限公司 | A kind of vertical rotating direct current electric arc furnace |
| CN110701912A (en) * | 2019-11-15 | 2020-01-17 | 中冶南方工程技术有限公司 | Electric arc furnace and furnace cover thereof |
-
2020
- 2020-04-23 CN CN202010325924.4A patent/CN111473641B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202153094U (en) * | 2011-06-08 | 2012-02-29 | 宝鸡铠丰科技发展有限公司 | Novel smelting electric arc furnace for fused magnesium oxide |
| CN102410727A (en) * | 2011-12-23 | 2012-04-11 | 龙南龙钇重稀土科技股份有限公司 | High-temperature smelting and reducing three-phase arc furnace |
| CN207280172U (en) * | 2017-10-18 | 2018-04-27 | 唐山首唐宝生功能材料有限公司 | Electric furnace arrangement for producing steel |
| CN110260647A (en) * | 2019-05-28 | 2019-09-20 | 江苏天楹环保能源成套设备有限公司 | A kind of vertical rotating direct current electric arc furnace |
| CN110701912A (en) * | 2019-11-15 | 2020-01-17 | 中冶南方工程技术有限公司 | Electric arc furnace and furnace cover thereof |
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