An electric furnace electrode control system

Abstract

The present invention discloses an electric furnace electrode control system, belonging to the field of electric furnace automatic control. This system can realize continuous adjustment of the electrode circle diameter and has the function of independent lifting of the three-phase electrodes. The hardware part of this control system includes a load-bearing shell, an installation base, a lifting device, a station adjustment device, a cross arm, an electrode circle adjustment device, an electrode clamping device, etc. Among them, the station adjustment device can drive the overall rotation of the load-bearing shell, the lifting device and the cross arm to achieve continuous heating of multiple ladles. Compared with the prior art, the present invention can significantly reduce energy consumption, improve production efficiency, avoid situations such as arc furnace burning, and ensure uniform temperature distribution in the furnace.

Description

Technical Field

[0001] The present invention belongs to the field of electric furnace automatic control, and particularly relates to an electric furnace electrode control system. Background Art

[0002] An electric arc furnace is an electric furnace that uses the high temperature generated by an electrode arc to smelt ores and metals. When a gas discharge forms an arc, the energy is very concentrated, and the temperature in the arc zone is above 3000°C. For smelting metals, the electric arc furnace has greater process flexibility than other steelmaking furnaces, can effectively remove impurities such as sulfur and phosphorus, the furnace temperature is easy to control, the equipment occupies a small area, and is suitable for the smelting of high-quality alloy steel. However, the existing electric arc furnace structure has the following technical problems:

[0003] 1) The electrode circle diameter of the existing electric arc furnace cannot be adjusted. Since the electrode circle diameter is directly related to energy consumption and output, when the diameter of the electrode circle in the electric furnace is too small, due to the small net distance between the three electrodes, the overlapping part of the three formed molten pools is too much, resulting in an overly concentrated heat zone in the center of the furnace hearth, reducing the resistance between the electrodes, the reaction area in the furnace is too small, the charge melting amount is low, the output is low, and the power consumption is necessarily high. If the electrode circle diameter of the electric furnace electrode is too large, the net distance between the three electrodes in the electric furnace is too large, resulting in too little overlapping part of the three formed molten pools, then there is a dead angle where the heat is not concentrated in the middle of the three molten pools, which is not conducive to production.

[0004] 2) During the operation of the electric arc furnace, it is necessary to frequently adjust the height of the electrodes. The three-phase electrodes of some existing electric arc furnace structures cannot be adjusted independently. Even if the three-phase electrodes of some electric arc furnace structures can be adjusted independently, their verticality and strength are low, and they are prone to shaking during use;

[0005] 3) During the process of heating the ladle in the electric arc furnace, the "one furnace, one ladle" structure is generally adopted. When the ladle is in the transportation, fixing, installation and other links, the electric arc furnace can only wait for the ladle to be ready before starting to heat, wasting a lot of working time. Summary of the Invention

[0006] In view of the above technical problems, the present invention provides an electric furnace electrode control system, which can realize continuous adjustment of the electrode circle diameter and has the function of independent lifting of the three-phase electrode height. The hardware part of the control system includes a load-bearing shell, an installation base, a lifting device, a station adjustment device, a cross arm, an electrode circle adjustment device, an electrode clamping device, etc. Among them, the station adjustment device can drive the load-bearing shell, the lifting device and the cross arm to rotate as a whole to realize continuous heating of multiple ladles.

[0007] The present invention solves the above problems through the following technical means:

[0008] An electric furnace electrode control system, characterized in that it includes a load-bearing shell, a mounting base, a lifting device, a station adjustment device, a cross arm, an electrode circle adjustment device, and an electrode clamping device, wherein: The load-bearing shell serves as the load-bearing main body and is rotatably installed on the foundation platform through the station adjustment device. Three upper through holes are provided on the upper side of the load-bearing shell, and a plurality of upper guide wheels are symmetrically arranged around the upper through holes. Three lower through holes are correspondingly provided on the lower side of the load-bearing shell, and a plurality of lower guide wheels are symmetrically arranged around the lower through holes; The mounting base is horizontally arranged at the bottom of the load-bearing shell. The mounting base includes two groups of double-headed hinge seats, four groups of equal-length mounting arms, and a horizontal mounting seat. The two groups of double-headed hinge seats are symmetrically installed at the bottom of the load-bearing shell. One end of the mounting arm is hinged to the double-headed hinge seat, and the other end of the mounting arm is fixed to the horizontal mounting seat. A reinforcing beam is arranged between the mounting arms; The bottom of the lifting device is horizontally fixed on the mounting base, and the top of the lifting device is fixed to the bottom of the cross arm; The station adjustment device is used to drive the load-bearing shell, the mounting base, the lifting device, and the cross arm to rotate as a whole. The station adjustment device includes a slide rail, a pulley, a rotating shaft seat, and a rotation driving device. The pulley is installed at the bottom of the load-bearing shell and cooperates with the slide rail to achieve a fixed-trajectory movement. The slide rail is laid on the foundation platform. The top of the rotating shaft seat is installed at the central position of the bottom of the load-bearing shell, and the bottom of the rotating shaft seat is installed on the foundation platform through the rotation driving device. The rotation driving device includes a motor or a hydraulic motor; The cross arm is divided into a first cross arm, a second cross arm, and a third cross arm that are horizontally, equidistantly, and parallelly arranged. The first cross arm and the third cross arm are symmetrically arranged, and their ends are both inclined outward by 120° to form inclined arms. Long grooves are symmetrically provided on the front and rear sides of the inclined arms, and sliding grooves are provided on the upper and lower inner walls of the inclined arms; The electrode circle adjustment device includes a variable-diameter driver, a mounting frame, a double-shaft hydraulic motor, and a bearing seat. The mounting frame is suspended and fixed between the first cross arm and the third cross arm. The two ends of the rotating shaft of the double-shaft hydraulic motor are arranged in the top and bottom bearing seats of the mounting frame. Two variable-diameter drivers are respectively sleeved on the two ends of the rotating shaft of the double-shaft hydraulic motor. The outer surface of the variable-diameter driver contacts the three electrode clamping devices, and the three electrode clamping devices are driven by the variable-diameter driver to move equidistantly to change the diameter of the electrode circle; The electrode clamping device is divided into a first clamp, a second clamp, and a third clamp. The first clamp is vertically installed on the inclined arm of the first cross arm. The first clamp can move back and forth along the long groove of the first cross arm under the drive of the variable-diameter driver. The second clamp is coaxially installed on the straight arm of the second cross arm. The second clamp can move back and forth along the straight arm of the second cross arm under the drive of the variable-diameter driver. The third clamp is vertically installed on the inclined arm of the third cross arm. The third clamp can move back and forth along the long groove of the third cross arm under the drive of the variable-diameter driver.

[0009] Preferably, a return spring is provided inside the inclined arm of the first cross arm, the straight arm of the second cross arm, and the inclined arm of the third cross arm. The return spring is arranged between the electrode clamping device and the end cover and is used to drive the electrode clamping device to closely contact the variable-diameter driver.

[0010] Preferably, the variable-diameter driver is composed of three symmetric driving arc surfaces. An installation hole is provided at the top of the variable-diameter driver. The driving arc surfaces are made of insulating materials, and a plurality of ball bearings are evenly arranged on their outer surfaces.

[0011] Preferably, the electrode clamping device includes a clamping housing, an arc-shaped clamping seat, a movable clamp, a conductive wire, a moving groove, a transmission plate, a clamping connecting piece, a clamping oil cylinder, and a roller row, where: an arc-shaped clamping seat and a movable clamp are provided at the end of the clamping housing of the electrode clamping device. The arc-shaped clamping seat and the movable clamp cooperate to fix the electrode. The outer wall of the movable clamp contacts the conductive wire. Both ends of the movable clamp are arranged on the transmission plate. The transmission plate is movably installed in the moving groove and is connected to the clamping oil cylinder through the clamping connecting piece. Multiple groups of roller rows are respectively arranged on the upper and lower surfaces of the clamping housing and cooperate with the sliding grooves on the inner walls of the cross arms.

[0012] Preferably, a driving wheel is further installed on the clamping housing of the electrode clamping device, and the driving wheel is used to contact the variable-diameter driver.

[0013] Preferably, the lifting device includes three groups of lifting oil cylinders, a lifting platform, a lifting column, a lifting sleeve, and a connecting seat. The bottom of the lifting oil cylinder is fixed on the horizontal mounting seat. The lifting platform is arranged on the telescopic rod of the lifting oil cylinder. The lifting column is coaxially arranged inside the lifting sleeve. The bottom of the lifting column is installed on the lifting platform. A connecting platform is provided at the top of the lifting column. The connecting platform is rotatably installed in the hinge hole of the lifting sleeve through a hinge shaft. A plurality of guide plates cooperating with the guide wheels are provided on the side wall of the lifting sleeve. The top of the lifting sleeve is connected to the cross arm through the connecting seat.

[0014] The above electric furnace electrode control system includes the following control methods:

[0015] 1) Electrode installation: The electric furnace electrode control system controls the three lifting oil cylinders to rise to the highest position and controls the three clamping oil cylinders to extend to the maximum position. After waiting for the operator to install the three electrodes on the movable clamp, the electric furnace electrode control system controls the three clamping oil cylinders to contract and reliably fixes the three electrodes.

[0016] 2) Electrode circle adjustment: The electric furnace electrode control system controls the electrode circle adjustment device to work, and changes the diameter of the electrode circle by controlling the three telescopic devices to adapt to ladles or furnace cavities with different inner diameters.

[0017] 3) Electrode power-on: The electric furnace electrode control system controls the closing of the vacuum switch and disconnecting switch in the main circuit of the transformer power supply, and disconnects the grounding switch of the transformer;

[0018] 4) Electrode lowering and arc starting: The electric furnace electrode control system issues a downward movement command to the three lifting cylinders, and the three electrodes move downward. The electric furnace electrode control system real-time detects the actual voltage values of the three electrodes:

[0019] When the actual voltage values of the three electrodes are all non-zero, the three electrodes continue to move downward until an arc is generated;

[0020] When the actual voltage value of one of the electrodes is zero, the corresponding electrode stops moving downward, moves upward and retracts to the waiting distance and then enters the waiting state, and the other electrodes continue to move downward until an arc is generated;

[0021] 5) Automatic control of electrode lifting and lowering: After the arc is generated, the electric furnace electrode control system uses an impedance regulator to automatically adjust the lifting heights of the three-phase electrodes;

[0022] 6) Electrode power-off: After heating is completed, the electric furnace electrode control system controls the disconnection of the vacuum switch and disconnecting switch in the main circuit of the transformer power supply, and closes the grounding switch of the transformer;

[0023] 7) Electrode rising: The electric furnace electrode control system controls the three lifting cylinders to move upward, and the three electrodes move upward until they reach the highest point;

[0024] 8) Electrode station adjustment: The electric furnace electrode control system controls the working of the station adjustment device. After the station adjustment device drives the load-bearing shell, installation base, lifting device, cross arm, electrode clamping device and the electrodes to rotate to a new station as a whole, repeat steps 3 to 8.

[0025] Preferably, during the adjustment of the electrode circle, the calculation method of the electrode circle diameter is as follows:

[0026] D P = 65%*(Di / K)+35%*((3.25*d) / cos30°), where D P is the electrode circle diameter, Di is the inner diameter of the electric furnace or ladle, K is an empirical coefficient with a value between 2.6 and 2.9, and d is the electrode diameter.

[0027] The electric furnace electrode control system of the present invention has the following beneficial effects:

[0028] 1) The present invention adopts a new type of electrode circle adjustment device, which can continuously adjust the diameter of the electrode circle to adapt to different inner diameters of ladles, avoid the problem of heat concentration caused by too small a diameter of the electrode circle, or the problems of heat death and furnace burning caused by too large a diameter of the electrode circle, and can significantly improve the material melting amount and output, and reduce energy consumption.

[0029] 2) The present invention adopts a novel lifting device. The lifting column and the lifting sleeve are in a hinged form. At the same time, a load-bearing shell guide wheel is configured. A guide plate is arranged on the outer surface of the lifting sleeve. The guide plate cooperates with the upper and lower through holes and the upper and lower guide wheels. On the one hand, it can realize the independent adjustment of the three-phase electrodes. On the other hand, it can maintain a high verticality and installation strength, and is not prone to shaking during use, and the lifting height is accurate.

[0030] 3) The present invention adopts a rotatable multi-station structure. The station adjustment device has two to three working positions, and each working position is separated by 90°. During the process of the electric arc furnace heating the ladle, the technical effect of "one furnace with multiple ladles" is achieved. After the ladle is heated, the adjacent ladle is directly heated. The electric arc furnace does not have to wait for the ladle to be ready before starting to heat, saving a large amount of working time. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 is the overall structural schematic diagram of the present invention;

[0033] Figure 2 is the structural schematic diagram of the electrode circle adjusting device in the present invention;

[0034] Figure 3 is the working schematic diagram of the electrode circle adjusting device in the present invention;

[0035] Figure 4 is the internal structural schematic diagram of the electrode circle adjusting device in the present invention;

[0036] Figure 5 is the structural schematic diagram of the variable diameter driver in the present invention;

[0037] Figure 6 is the installation schematic diagram of the universal ball in the present invention;

[0038] Figure 7 is the installation schematic diagram of the return spring in the present invention;

[0039] Figure 8 is the external structural schematic diagram of the electrode clamping device in the present invention;

[0040] Figure 9 is the internal structural schematic diagram of the electrode clamping device in the present invention;

[0041] Figure 10 is the first structural schematic diagram of the driving wheel in the present invention;

[0042] Figure 11 is the second structural schematic diagram of the driving wheel in the present invention;

[0043] Figure 12 is the structural schematic diagram of the load-bearing shell in the present invention;

[0044] Figure 13 is the installation schematic diagram of the guide wheel in the present invention;

[0045] Figure 14 is the structural schematic diagram of the installation base in the present invention;

[0046] Figure 15 is the structural schematic diagram of the lifting device in the present invention;

[0047] Figure 16 is the structural schematic diagram of the lifting column in the present invention;

[0048] Figure 17 is the structural schematic diagram of the station adjustment device in the present invention.

[0049] Among them, 1 - load-bearing shell, 101 - upper through hole, 102 - upper guide wheel, 103 - lower through hole, 104 - lower guide wheel, 2 - installation base, 201 - double-headed hinge seat, 202 - installation arm, 203 - horizontal installation seat, 204 - strengthening beam, 3 - lifting device, 301 - lifting oil cylinder, 302 - lifting platform, 303 - lifting column, 304 - lifting sleeve, 305 - connecting seat, 3031 - connecting platform, 3032 - hinge shaft, 3041 - hinge hole, 3042 - guide plate, 4 - station adjustment device, 401 - slide rail, 402 - pulley, 403 - rotating shaft seat, 5 - cross arm, 501 - first cross arm, 502 - second cross arm, 503 - third cross arm, 504 - long slot, 505 - sliding slot, 506 - return spring, 6 - electrode circle adjustment device, 601 - variable diameter driver, 602 - mounting bracket, 603 - double-shaft hydraulic motor, 604 - bearing seat, 605 - driving arc surface, 606 - mounting hole, 607 - universal ball, 7 - electrode clamping device, 701 - first clamp, 702 - second clamp, 703 - third clamp, 704 - clamping housing, 705 - arc-shaped clamping seat, 706 - movable clamp, 707 - conducting wire, 708 - moving slot, 709 - transmission plate, 710 - clamping connecting piece, 711 - clamping oil cylinder, 712 - roller row, 713 - driving wheel, 8 - electrode. Detailed implementation manners

[0050] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0051] The present invention will be described in detail below with reference to the drawings.

[0052] Embodiment 1

[0053] As Figure 1 shown, the electric furnace electrode control system includes a load-bearing shell 1, a mounting base 2, a lifting device 3, a working position adjusting device 4, a cross arm 5, an electrode circle adjusting device 6, and an electrode clamping device 7. In this embodiment, the load-bearing shell 1 serves as the load-bearing main body and is rotatably installed on the foundation platform through the working position adjusting device 4. The foundation platform is a cement platform or a load-bearing bracket. The mounting base 2 is horizontally arranged at the bottom of the load-bearing shell 1. The bottom of the lifting device 3 is horizontally fixed on the mounting base 2, and the top of the lifting device 3 is fixed to the bottom of the cross arm 5. The lifting device 3 is used to drive the cross arm 5 to lift and lower, and the working position adjusting device 4 is used to drive the load-bearing shell 1, the mounting base 2, the lifting device 3, and the cross arm 5 to rotate as a whole.

[0054] As Figure 2 and Figure 3 shown, the cross arm 5 is divided into a first cross arm 501, a second cross arm 502, and a third cross arm 503 that are horizontally, equidistantly, and parallelly arranged. The first cross arm 501 and the third cross arm 503 are symmetrically arranged, and their ends are both inclined outward by 120° to form inclined arms. Long grooves 504 are symmetrically opened on the front and rear sides of the inclined arms. The long grooves 504 are used to movably install the electrode clamping device 7. Slide grooves 505 are provided on the upper and lower inner walls of the inclined arms. The slide grooves 505 are used to movably install the roller row 712 of the electrode clamping device 7.

[0055] In this embodiment, the three electrode clamping devices 7 are all movably installed at the end of the cross arm 5. A spring is provided between the electrode clamping device 7 and the cross arm 5. Specifically, the first gripper 701 is vertically installed on the inclined arm of the first cross arm 501. The first gripper 701 can move back and forth along the long slot 504 of the first cross arm 501 under the drive of the variable diameter driver 601. The second gripper 702 is coaxially installed on the straight arm of the second cross arm 502. The second gripper 702 and the straight arm adopt a telescopic sleeve form. The second gripper 702 can move back and forth along the straight arm of the second cross arm 502 under the drive of the variable diameter driver 601. The third gripper 703 is vertically installed on the inclined arm of the third cross arm 503. The third gripper 703 can move back and forth along the long slot 504 of the third cross arm 503 under the drive of the variable diameter driver 601.

[0056] As Figures 2 to 5 shown, the electrode circle adjusting device 6 includes a variable diameter driver 601, a mounting bracket 602, a double-shaft hydraulic motor 603 and a bearing block 604. The mounting bracket 602 is suspended and fixed between the first cross arm 501 and the third cross arm 503. The mounting bracket 602 is of a Y-shaped structure and is divided into upper and lower layers. The two sides of the Y-shaped structure are installed on the side walls of the first cross arm 501 and the third cross arm 503 through flanges. The two ends of the rotating shaft of the double-shaft hydraulic motor 603 are arranged in the top and bottom bearing blocks 604 of the mounting bracket 602. Two variable diameter drivers 601 are respectively horizontally sleeved on the two ends of the rotating shaft of the double-shaft hydraulic motor 603. The outer surface of the variable diameter driver 601 contacts the three electrode clamping devices 7. By driving the three electrode clamping devices 7 to move equidistantly through the variable diameter driver 601, the diameter of the electrode circle is changed. Specifically, the electrode circle adjusting device 6 adopts a two-layer structure, and two variable diameter drivers 601 are symmetrically arranged to ensure the stable movement of the electrode clamping device 7. During actual operation, to ensure that the positions of the two variable diameter drivers 601 are the same, their positions can be locked by pins and keys.

[0057] In this embodiment, the variable diameter driver 601 is composed of three symmetric driving arc surfaces 605. An installation hole 606 is opened at the top of the variable diameter driver 601. During specific operation, the driving arc surface 605 is made of an insulating material, and a plurality of ball bearings 607 are uniformly arranged on its outer surface. The ball bearings 607 can greatly reduce the friction force and the movement resistance of the electrode clamping device 7.

[0058] In this embodiment, a return spring 506 is arranged inside the inclined arm of the first cross arm 501, the straight arm of the second cross arm 502, and the inclined arm of the third cross arm 503. The return spring 506 is arranged between the electrode clamping device 7 and the end cover and is used to drive the electrode clamping device 7 to closely contact the variable diameter driver 601. Figure 7The internal structures of the first gripper 701 and the third gripper 703 are shown. Similarly, a return spring is also provided between the end of the second gripper 702 and the straight arm sleeve, but the view is not given here, only the arrangement direction is different.

[0059] The specific working process is as follows: The three-phase electrodes are located on the same circumference. When encountering different ladles or furnaces, it is necessary to adjust the optimal electrode circle diameter. The control system drives the double-shaft hydraulic motor to rotate forward or backward by controlling the hydraulic valve. At this time, the variable-diameter driver 601 starts to rotate in the expected direction. Refer to Figure 3 , when the variable-diameter driver 601 moves clockwise, the electrode circle diameter gradually increases; when the variable-diameter driver 601 moves counterclockwise, the electrode circle diameter gradually decreases. The size of the driving arc surface 605 can be designed according to the actual situation to meet different diameter ranges. In this embodiment, the driving method only uses one driving device, that is, one hydraulic motor, to achieve the equidistant movement of the three electrodes 8, realizing different-diameter electrode circles, avoiding the heat concentration problem caused by too small an electrode circle diameter or the heat loss and furnace burning problems caused by too large an electrode circle diameter, and can significantly improve the material melting amount and production output, and significantly reduce the energy consumption.

[0060] Embodiment 2

[0061] In this embodiment, the calculation method of the electrode circle diameter is as follows:

[0062] D P =α*Di / K + β*γ*d / cos30°, where D P is the electrode circle diameter, Di is the inner diameter of the electric furnace or ladle, K is an empirical coefficient, 2.6 ≤ K ≤ 2.9, d is the electrode diameter, α is the first proportion coefficient, 0.6 ≤ α ≤ 0.65, β is the second proportion coefficient, 0.35 ≤ β ≤ 0.4, and γ is the diameter coefficient, 3 ≤ γ ≤ 3.5.

[0063] It should be noted that the selection of the electrode circle diameter D P is directly positively correlated with two factors: the electrode diameter d and the inner diameter Di of the electric furnace or ladle. Specifically, when the electrode diameter d increases, the electrode circle diameter D P needs to increase; when the inner diameter Di of the electric furnace or ladle increases, the electrode circle diameter D P also needs to increase.

[0064] It should be further noted that the first proportion coefficient α and the second proportion coefficient β are used to balance the proportion of the above factors. Generally, α is taken as 0.65, β is taken as 0.35, and the diameter coefficient γ is the distance between the centers of two electrodes. Generally, 3.25 is selected. Therefore, the following general formula is obtained: D P= 65% * Di / K + 35% * 3.25 * d / cos30°, the selection of the above parameters also needs to be adjusted according to different working conditions to achieve the best heating effect, that is, there is no heating dead zone in the heating areas of the three electrodes and the overlapping area is the smallest. At this time, the circumferences of the molten pool circles formed between the three electrodes intersect at the center of the furnace, which can enable the circulation between the three molten pools, the heat is relatively concentrated, and it will not cause the heat to be too concentrated and accelerate the damage of the furnace bottom. In this embodiment, the precise position control of the oil cylinder is completed by existing equipment, and a position sensor or a high-precision hydraulic control valve can be configured, for example: a wire-drawing encoder or a resistance ruler.

[0065] Embodiment Three

[0066] As Figures 7 to 9 shown, the electrode clamping device 7 includes a clamping housing 704, an arc-shaped clamping seat 705, a movable clamp 706, a conductive wire 707, a movable groove 708, a transmission plate 709, a clamping connecting piece 710, a clamping oil cylinder 711 and a roller row 712. In this embodiment, an arc-shaped clamping seat 705 and a movable clamp 706 are arranged at the end of the clamping housing 704 of the electrode clamping device 7. The arc-shaped clamping seat 705 and the movable clamp 706 cooperate to fix the electrode 8. The outer wall of the movable clamp 706 is in contact with the conductive wire 707. Both ends of the movable clamp 706 are arranged on the transmission plate 709. The transmission plate 709 is movably installed in the movable groove 708 and is connected to the clamping oil cylinder 711 through the clamping connecting piece 710. Two groups of roller rows 712 are respectively arranged on the upper and lower surfaces of the clamping housing 704 and cooperate with the chute 505 on the inner wall of the cross arm 5. It should be noted that by controlling the clamping oil cylinder 711 through a hydraulic valve, the automatic operation of the clamping device 7 can be realized.

[0067] Figure 8 Only the arrangement of the two groups of roller rows 712 of the first clamp 701 and the second clamp 702 is shown. A telescopic sleeve structure is adopted between the third clamp 703 and the straight arm. The rolling directions of the two groups of roller rows 712 are arranged in parallel, which is different from the vertical arrangement direction of the first clamp 701 and the second clamp 702.

[0068] Embodiment Four

[0069] As Figure 10 and Figure 11 shown, a driving wheel 713 is also installed on the clamping housing 704 of the electrode clamping device 7. The driving wheel 713 is used to contact the variable diameter driver 601. Specifically, the installation method of the driving wheel 713 can adopt various forms. The purpose is to reduce the movement resistance of the electrode clamping device 7. By contacting the variable diameter driver 601 through the driving wheel 713, the force application point and force application direction of the electrode clamping device 7 are changed, making it closer to the long groove and the chute, and achieving a more smooth and stable movement effect.

[0070] Example Five

[0071] As Figure 12 and Figure 13 shown, the load-bearing shell 1 is rotatably installed on the foundation platform as the load-bearing main body. The foundation platform is a cement structure or a frame base. Three upper through-holes 101 are provided on the upper load-bearing plate of the load-bearing shell 1, and a plurality of upper guide wheels 102 are symmetrically arranged around the upper through-holes 101. Three lower through-holes 103 are correspondingly provided on the lower load-bearing plate of the load-bearing shell 1, and a plurality of lower guide wheels 104 are symmetrically arranged around the lower through-holes 103. Specifically, the upper through-holes 101 and the lower through-holes 103 are correspondingly arranged for vertically installing the lifting sleeve 304. Each through-hole is configured with four to eight guide wheels, and the guide wheels are symmetrically arranged and used to guide the vertical movement of the lifting sleeve 304. Good verticality can be ensured through double-row fixation and support.

[0072] Example Six

[0073] As Figure 14 shown, the installation base 2 is arranged at the bottom of the load-bearing shell 1 and is used for installing the lifting device 3. The installation base 2 includes two groups of double-headed hinge seats 201, four groups of equal-length installation arms 202 and a horizontal installation seat 203. The two groups of double-headed hinge seats 201 are parallel and symmetrically installed at the bottom of the load-bearing shell 1. One end of the installation arm 202 is hinged to the double-headed hinge seat 201, and the other end of the installation arm 202 is fixed to the horizontal installation seat 203. A reinforcing beam 204 is arranged between the installation arms 202. The four installation arms 202 and the horizontal installation seat 203 form a swingable frame structure, which is used to eliminate the errors occurring during the installation process, avoid movement interference, and at the same time, ensure that the horizontal installation seat 203 is always horizontal under the action of gravity and can rotate along with the load-bearing shell 1.

[0074] Example Seven

[0075] As Figure 15 and Figure 16 shown, the lifting device 3 includes three groups of lifting oil cylinders 301, a lifting platform 302, a lifting column 303, a lifting sleeve 304 and a connecting seat 305. Specifically, the lifting oil cylinders 301 are controlled by hydraulic valves. The bottoms of the lifting oil cylinders 301 are fixed on the horizontal installation seat 203. The lifting platform 302 is arranged on the telescopic rods of the lifting oil cylinders 301, and the lifting platform 302 can move along with the telescopic rods. The lifting column 303 is coaxially arranged inside the lifting sleeve 304. The bottom of the lifting column 303 is installed on the lifting platform 302 through a flange, and the top of the lifting column 303 is hinged. Specifically, a connecting platform 3031 is arranged at the top of the lifting column 303, and the connecting platform 3031 is rotatably installed in the hinge hole 3041 of the lifting sleeve 304 through a hinge shaft 3032. When the lifting oil cylinders 301 move, they will drive the lifting platform 302, the lifting column 303, the lifting sleeve 304 and the connecting seat 305 to move accordingly.

[0076] It should be noted that a plurality of guide plates 3042 for cooperating with the guide wheels are provided on the side wall of the lifting sleeve 304. The guide plates 3042 are in a V-shaped structure and are buckled on the side wall of the lifting sleeve 304. The planes on both sides of the V-shaped structure are used to closely adhere to the rolling surfaces of the guide wheels.

[0077] Example Eight

[0078] As Figure 17 shown, the station adjustment device 4 includes a slide rail 401, a pulley 402, a rotating shaft seat 403 and a rotation driving device. Specifically, the pulley 402 is installed at the bottom of the load-bearing shell 1 and cooperates with the slide rail 401 to achieve a fixed-track movement. The slide rail 401 is laid on the base platform. The top of the rotating shaft seat 403 is installed at the center of the bottom of the load-bearing shell 1. The bottom of the rotating shaft seat 403 is installed on the base platform through the rotation driving device. The rotation driving device includes a motor or a hydraulic motor, and the motor or the hydraulic motor transmits torque to the rotating shaft seat 403 through a speed reducer. It should be noted that the station adjustment device has two to three working positions, and each working position is separated by 90°. At this time, the slide rail 401 can adopt a 180° track or a 270° track, etc. The angle between the stations should also be related to the actual ladle size, and multiple stations can be flexibly set, with an equal distance interval of 30° to 60° from each other.

[0079] Example Nine

[0080] The electric furnace electrode control system in the present invention includes the following control methods, but does not include conventional operations such as electrode replacement and electrode elongation.

[0081] 1) Electrode installation: The electric furnace electrode control system controls the three lifting cylinders to rise to the highest position and controls the three telescopic cylinders to extend to the maximum position. After waiting for the operator to install the three electrodes on the moving clamp, the electric furnace electrode control system controls the three telescopic cylinders to contract and firmly fixes the three electrodes.

[0082] Specifically, when the operator is operating and installing, try to make the bottoms of the three electrodes flush.

[0083] 2) Electrode circle adjustment: The electric furnace electrode control system controls the electrode circle adjustment device to work, and changes the diameter of the electrode circle by controlling the three telescopic devices to adapt to ladles or furnace cavities with different inner diameters; the electrode circle adjustment device can continuously adjust the diameter of the electrode circle to adapt to different ladle inner diameters, avoiding the problem of heat concentration caused by too small a diameter of the electrode circle or the problems of heat death and furnace burning caused by too large a diameter of the electrode circle, and can significantly improve the amount of material melted and the output, and reduce energy consumption.

[0084] 3) Electrode power-on: The electric furnace electrode control system controls the vacuum switch and the disconnector in the main circuit of the transformer power supply to be closed, and disconnects the grounding switch of the transformer.

[0085] 4) Electrode lowering to initiate arc: The electric furnace electrode control system issues a downward movement command to the three lifting cylinders, and the three electrodes move downward. The electric furnace electrode control system continuously detects the actual voltage values of the three electrodes:

[0086] When the actual voltage values of the three electrodes are all non-zero, the three electrodes continue to move downward until an arc is generated. Specifically, the fact that the actual voltage values of the three electrodes are all non-zero indicates that the three electrodes are descending smoothly at this time, and no single electrode is descending too fast.

[0087] When the actual voltage value of one of the electrodes is zero, the corresponding electrode stops moving downward, moves upward and retracts to the waiting distance and then enters the waiting state, while the other electrodes continue to move downward until an arc is generated; specifically, the waiting distance is generally 5 to 10 cm. When the actual voltage value of one of the electrodes is zero, it means that the electrode has descended too fast and has contacted the charge in the furnace. At this time, the "equal head waiting" program should be started. On the one hand, it can prevent the electrode from breaking, and on the other hand, it can compensate for the error of the mechanical transmission parts to ensure smooth arc initiation.

[0088] 5) Automatic control of electrode lifting: After the arc is generated, the electric furnace electrode control system uses an impedance regulator to automatically adjust the lifting height of the three-phase electrodes;

[0089] Specifically, the impedance regulator can adopt existing technologies and equipment, such as Siemens' S7-300, 400, 1500 series, or ControlLogix RSLogix5000 series PLC. The refining furnace resistance includes the contact resistance from the transformer to the electrode, and the refining furnace reactance is caused by the wiring between the short-circuit three-phase cables, which changes with the lifting position of the electrode. During the smelting process, the electrode arc is resistive, and the arc resistance changes with the length of the arc. The length of the arc is adjusted by the lifting of the electrode. The actual value is compared with the corrected value, and the impedance deviation value is output, which drives the servo valve through power amplification to control the electrode to rise or fall, thereby realizing the adjustment of the impedance.

[0090] 6) Electrode power-off: After the heating is completed, the electric furnace electrode control system controls the vacuum switch and the disconnector in the main circuit of the transformer power supply to be disconnected, and the earthing switch of the transformer to be closed;

[0091] 7) Electrode rising: The electric furnace electrode control system controls the three lifting cylinders to move upward, and the three electrodes move upward until they reach the highest point;

[0092] 8) Electrode Station Adjustment: The electric furnace electrode control system controls the operation of the station adjustment device. After the station adjustment device drives the load-bearing shell, mounting base, lifting device, cross arm, clamping device, and the electrode as a whole to rotate to a new station, steps 3 to 8 are repeated. Specifically, the station adjustment device has two to three working positions, and each working position is separated by 90°.

[0093] Embodiment Ten

[0094] In this embodiment, the impedance regulator can not only adopt the existing technologies and equipment, but also adopt a new type of impedance controller. By means of control such as impedance feedback control, overcurrent feedforward control, and short-circuit feedforward control, the stability and sensitivity of electrode adjustment are improved. Specifically, the impedance regulator includes a set impedance calculation and correction unit, an actual impedance sampling and calculation unit, and an impedance adjustment control output unit.

[0095] Specifically, the set impedance calculation and correction unit obtains the basic impedance set value according to the arc heating power supply system model, and superimposes the impedance increase correction for gear switch shifting protection, the impedance reduction correction for arc starting and slag melting, and the impedance set value limiting link to obtain the final impedance set value actually participating in control; the actual impedance sampling and calculation unit performs scale transformation, coefficient correction, and filtering processing on the actually collected secondary voltage and secondary current signals, then divides the two, and the quotient of the two is filtered and limited to obtain the actual impedance value actually participating in control; according to the impedance set value and the actual impedance value, the impedance control deviation is obtained, and it is automatically adjusted and controlled by a PI controller with a proportional coefficient adaptive, an overcurrent feedforward controller, and a short-circuit feedforward controller. After passing through the proportional valve hydraulic characteristic compensation, manual control, pilot valve control, and filter link, it outputs to drive the hydraulic proportional valve to control the lifting of the electrode column, achieving the purpose of stable arc combustion and uniform heating.

[0096] It should be noted that, in combination with the heating equivalent circuit and the stable working boundary conditions of the transformer, a "power circle diagram" of the reactive power - active power correspondence relationship can be generated by computer software, and the gear switch positions and the corresponding impedance set values under different power factors after being constrained by the boundary conditions are stored in the memory data block of the electrode adjustment system in the form of a matrix table for the operator to select as the basic impedance set value for electrode adjustment.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electric furnace electrode control system, characterized in that, it includes a load-bearing shell (1), a mounting base (2), a lifting device (3), a working position adjustment device (4), a cross arm (5), an electrode circle adjustment device (6) and an electrode clamping device (7), wherein: The load-bearing shell (1) serves as a load-bearing main body and is rotatably mounted on the foundation platform through the working position adjustment device (4). Three upper through holes (101) are provided on the upper side of the load-bearing shell (1), and a plurality of upper guide wheels (102) are symmetrically arranged around the upper through holes (101). Three lower through holes (103) are correspondingly provided on the lower side of the load-bearing shell (1), and a plurality of lower guide wheels (104) are symmetrically arranged around the lower through holes (103); The mounting base (2) is horizontally arranged at the bottom of the load-bearing shell (1). The mounting base (2) includes two groups of double-headed hinge seats (201), four groups of equal-length mounting arms (202) and a horizontal mounting seat (203). The two groups of double-headed hinge seats (201) are symmetrically mounted at the bottom of the load-bearing shell (1). One end of the mounting arm (202) is hinged to the double-headed hinge seat (201), and the other end of the mounting arm (202) is fixed to the horizontal mounting seat (203). A reinforcing beam (204) is arranged between the mounting arms (202); The bottom of the lifting device (3) is horizontally fixed on the mounting base (2), and the top of the lifting device (3) is fixed to the bottom of the cross arm (5); The working position adjustment device (4) is used to drive the load-bearing shell (1), the mounting base (2), the lifting device (3) and the cross arm (5) to rotate as a whole; The cross arm (5) is divided into a first cross arm (501), a second cross arm (502) and a third cross arm (503) which are horizontally, equidistantly and parallelly arranged. The first cross arm (501) and the third cross arm (503) are symmetrically arranged, and their ends are both inclined outward by 120° to form inclined arms. Long grooves (504) are symmetrically provided on the front and rear sides of the inclined arms, and sliding grooves (505) are provided on the upper and lower inner walls of the inclined arms; The electrode circle adjustment device (6) includes a variable diameter driver (601), a mounting frame (602), a double-shaft hydraulic motor (603) and a bearing seat (604). The mounting frame (602) is suspended and fixed between the first cross arm (501) and the third cross arm (503). The two ends of the rotating shafts of the double-shaft hydraulic motor (603) are arranged in the bearing seats (604) at the top and bottom of the mounting frame (602). Two variable diameter drivers (601) are respectively sleeved on the rotating shafts at both ends of the double-shaft hydraulic motor (603). The outer surface of the variable diameter driver (601) contacts the three electrode clamping devices (7), and the three electrode clamping devices (7) are driven by the variable diameter driver (601) to move equidistantly to change the diameter of the electrode circle; The electrode clamping device (7) is divided into a first clamp (701), a second clamp (702) and a third clamp (703). The first clamp (701) is vertically installed on the inclined arm of the first cross arm (501). The first clamp (701) can move back and forth along the long slot (504) of the first cross arm (501) under the drive of the variable diameter driver (601). The second clamp (702) is coaxially installed on the straight arm of the second cross arm (502). The second clamp (702) can move back and forth along the straight arm of the second cross arm (502) under the drive of the variable diameter driver (601). The third clamp (703) is vertically installed on the inclined arm of the third cross arm (503). The third clamp (703) can move back and forth along the long slot (504) of the third cross arm (503) under the drive of the variable diameter driver (601). A return spring (506) is arranged inside the inclined arm of the first cross arm (501), the straight arm of the second cross arm (502), and the inclined arm of the third cross arm (503). The return spring (506) is arranged between the electrode clamping device (7) and the end cover and is used to drive the electrode clamping device (7) to closely contact the variable diameter driver (601). The variable diameter driver (601) is composed of three symmetric drive arc surfaces (605), and an installation hole (606) is provided at the top of the variable diameter driver (601).

2. The electric furnace electrode control system according to claim 1, characterized in that the drive arc surface (605) is made of an insulating material, and a plurality of ball bearings (607) are evenly arranged on its outer surface.

3. The electric furnace electrode control system according to claim 2, characterized in that the electrode clamping device (7) includes a clamping housing (704), an arc-shaped clamping seat (705), a movable clamp (706), a conductive wire (707), a movable slot (708), a transmission plate (709), a clamping connecting piece (710), a clamping oil cylinder (711) and a roller row (712), wherein: An arc-shaped clamping seat (705) and a movable clamp (706) are arranged at the end of the clamping housing (704) of the electrode clamping device (7). The arc-shaped clamping seat (705) and the movable clamp (706) cooperate to fix the electrode (8). The outer wall of the movable clamp (706) is in contact with the conductive wire (707). Both ends of the movable clamp (706) are arranged on the transmission plate (709). The transmission plate (709) is movably installed in the movable slot (708) and is connected to the clamping oil cylinder (711) through the clamping connecting piece (710). Multiple groups of roller rows (712) are respectively arranged on the upper and lower surfaces of the clamping housing (704) and cooperate with the sliding slot (505) on the inner wall of the cross arm (5).

4. The electric furnace electrode control system according to claim 3, characterized in that a driving wheel (713) is further installed on the clamping housing (704) of the electrode clamping device (7), and the driving wheel (713) is used to contact the variable diameter driver (601).

5. The electric furnace electrode control system according to claim 4, It is characterized in that the lifting device (3) includes three groups of lifting oil cylinders (301), a lifting table (302), a lifting column (303), a lifting sleeve (304) and a connecting seat (305). The bottom of the lifting oil cylinder (301) is fixed on the horizontal mounting seat (203). The lifting table (302) is arranged on the telescopic rod of the lifting oil cylinder (301). The lifting column (303) is coaxially arranged inside the lifting sleeve (304). The bottom of the lifting column (303) is mounted on the lifting table (302). The top of the lifting column (303) is provided with a connecting platform (3031). The connecting platform (3031) is rotatably mounted in the hinge hole (3041) of the lifting sleeve (304) through a hinge shaft (3032). A plurality of guide plates (3042) cooperating with guide wheels are arranged on the side wall of the lifting sleeve (304). The top of the lifting sleeve (304) is connected to the cross arm (5) through the connecting seat (305).

6. The electric furnace electrode control system according to claim 5 It is characterized in that the station adjustment device (4) includes a slide rail (401), a pulley (402), a rotating shaft seat (403) and a rotation driving device. The pulley (402) is mounted at the bottom of the load-bearing shell (1) and cooperates with the slide rail (401) to realize a fixed-track movement. The slide rail (401) is laid on the foundation platform. The top of the rotating shaft seat (403) is mounted at the central position of the bottom of the load-bearing shell (1). The bottom of the rotating shaft seat (403) is mounted on the foundation platform through the rotation driving device. The rotation driving device includes a motor or a hydraulic motor.

7. The electric furnace electrode control system according to claim 6 It is characterized in that it includes the following control methods: 1) Electrode installation: The electric furnace electrode control system controls the three lifting oil cylinders to rise to the highest position and controls the three clamping oil cylinders to extend to the maximum position. After waiting for the operator to install the three electrodes on the moving clamp, the electric furnace electrode control system controls the three clamping oil cylinders to contract and reliably fixes the three electrodes. 2) Electrode circle adjustment: The electric furnace electrode control system controls the electrode circle adjustment device to work, and changes the diameter of the electrode circle by controlling the three telescopic devices to adapt to ladles or furnace cavities with different inner diameters. 3) Electrode power-on: The electric furnace electrode control system controls the vacuum switch and the disconnector in the main circuit of the transformer power supply to be closed, and disconnects the grounding switch of the transformer. 4) Electrode lowering and arc starting: The electric furnace electrode control system issues a downward movement command to the three lifting oil cylinders, and the three electrodes move downward. The electric furnace electrode control system real-time detects the actual voltage values of the three electrodes: When the actual voltage values of the three electrodes are not zero, the three electrodes continue to move downward until an arc is generated. When the actual voltage value of one of the electrodes is zero, the corresponding electrode stops moving downward, moves upward and retracts to the waiting distance and then enters the waiting state, and the other electrodes continue to move downward until an arc is generated. 5) Automatic control of electrode lifting: After the arc is generated, the electric furnace electrode control system uses an impedance regulator to automatically adjust the lifting heights of the three-phase electrodes. 6) Electrode power-off: After heating is completed, the electric furnace electrode control system controls the disconnection of the vacuum switch and disconnecting switch in the main circuit of the transformer power supply, and closes the earthing switch of the transformer; 7) Electrode lifting: The electric furnace electrode control system controls the upward operation of the three lifting cylinders, and the three electrodes move upward until they reach the highest point; 8) Electrode station adjustment: The electric furnace electrode control system controls the operation of the station adjustment device. After the station adjustment device drives the load-bearing shell, mounting base, lifting device, cross arm, electrode clamping device and the electrodes as a whole to rotate to a new station, repeat steps 3 to 8.

8. The control method of the electric furnace electrode control system according to claim 7, characterized in that during the adjustment of the electrode circle, the calculation method of the diameter of the electrode circle is as follows: D P = 65% * (Di / K) + 35% * ((3.25 * d) / cos 30°), where D P is the electrode circle diameter, Di is the inner diameter of the electric furnace or ladle, K is an empirical coefficient with a value between 2.6 and 2.9, and d is the electrode diameter.

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