阅读说明：本技术 一种钢包精炼炉电极调节系统 (Electrode adjusting system of ladle refining furnace ) 是由 陈勇 田柏峰 孙睿 于 2021-02-05 设计创作，主要内容包括：本发明公开了一种钢包精炼炉电极调节系统,属于电炉控制技术领域,具体涉及一种三相电极立柱可以独立、自动升降的调节控制系统,该钢包精炼炉电极调节系统的硬件部分包括旋转基架、基座、升降装置、工位调整装置、横臂和夹持装置,其中：升降装置采用独立方案,可以实现每根电极立柱的自由升降,工位调整装置能够实现电极立柱的整体旋转、以实现多个钢包的不间断连续加热；弧炉电极调节系统的软件部分采用阻抗控制策略,能够根据功率圆图预选的最佳工作点自动调节电极状态。与现有技术相比,本发明能够显著降低能耗,提高生产效率,减轻电炉对电网的干扰。(The invention discloses an electrode adjusting system of a ladle refining furnace, belonging to the technical field of electric furnace control, in particular to an adjusting control system with a three-phase electrode upright post capable of independently and automatically lifting, wherein the hardware part of the electrode adjusting system of the ladle refining furnace comprises a rotating base frame, a base, a lifting device, a station adjusting device, a cross arm and a clamping device, wherein: the lifting device adopts an independent scheme, free lifting of each electrode upright column can be realized, and the station adjusting device can realize integral rotation of the electrode upright columns so as to realize uninterrupted continuous heating of a plurality of steel ladles; the software part of the arc furnace electrode adjusting system adopts an impedance control strategy, and the electrode state can be automatically adjusted according to the optimal working point preselected by the power circular diagram. Compared with the prior art, the invention can obviously reduce energy consumption, improve production efficiency and reduce the interference of the electric furnace to a power grid.)

1. The utility model provides a ladle refining furnace electrode governing system which characterized in that, includes rotating pedestal (1), base (2), elevating gear (3), station adjusting device (4), xarm (5) and clamping device (6), wherein:

the rotary pedestal (1) is rotatably arranged on a base platform as a bearing main body, three upper through holes (101) are formed in the upper side of the rotary pedestal (1), a plurality of upper guide wheels (102) are symmetrically arranged around the upper through holes (101), three lower through holes (103) are correspondingly formed in the lower side of the rotary pedestal (1), and a plurality of lower guide wheels (104) are symmetrically arranged around the lower through holes (103);

the base (2) is arranged at the bottom of the rotary pedestal (1) and used for mounting the lifting device (3), the base (2) comprises two groups of double-headed hinge seats (201), four groups of 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 rotary pedestal (1), one end of each mounting arm (202) is hinged to the corresponding double-headed hinge seat (201), the other end of each mounting arm (202) is fixed on the corresponding horizontal mounting seat (203), and a reinforcing beam (204) is arranged between the mounting arms (202);

the lifting device (3) comprises three groups of lifting oil cylinders (301), a lifting platform (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 base (203), the lifting platform (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 installed on the lifting platform (302), the top of the lifting column (303) is provided with a connecting platform (3031), the connecting platform (3031) is rotatably installed in a hinge hole (3041) of the lifting sleeve (304) through a hinge shaft (3032), a plurality of guide plates (3042) which are matched with the guide wheels to work are arranged on the side wall of the lifting sleeve (304), and the top of the lifting sleeve (304) is connected with the cross arm (5) through a connecting seat (305);

the station adjusting device (4) comprises a sliding rail (401), a pulley (402), a rotating shaft seat (403) and a rotary driving device, the pulley (402) is installed at the bottom of the rotary base frame (1) and is matched with the sliding rail (401) to work to realize fixed-track movement, the sliding rail (401) is laid on a base table, the top of the rotating shaft seat (403) is installed at the central position of the bottom of the rotary base frame (1), the bottom of the rotating shaft seat (403) is installed on the base table through the rotary driving device, and the rotary driving device comprises a motor or a hydraulic motor; one end of the cross arm (5) is connected with a clamping device (6) for fixing the electrode (7), and the other end of the cross arm (5) is connected with a cable (8).

2. The ladle refining furnace electrode adjustment system according to claim 1, wherein the cross arm (5) comprises a first cross arm (501), a second cross arm (502) and a third cross arm (503) which are horizontally and parallelly arranged, the first cross arm (501) and the third cross arm (503) are symmetrically arranged, the ends of the first cross arm and the third cross arm are inclined outwards by an angle α, the end of the second cross arm (502) is inclined downwards by an angle α, and the angle α ranges from 90 ° to 150 °.

3. The ladle refining furnace electrode adjusting system according to claim 2, wherein the number of the clamping devices (6) is three, the three clamping devices (6) are respectively installed at the ends of the cross arm (5), the first clamping device is vertically installed at the end of the first cross arm (501), the second clamping device is horizontally installed at the end of the second cross arm (502), and the third clamping device is vertically installed at the end of the third cross arm (503), wherein:

arc-shaped clamping seats (602) and movable clamps (603) are arranged at the tail ends of clamping shells (601) of the clamping devices (6), the arc-shaped clamping seats (602) and the movable clamps (603) are matched for work and are used for fixing electrodes (7), the outer walls of the movable clamps (603) are contacted with conductive wires (604), two ends of the movable clamps (603) are arranged on a transmission plate (606), and the transmission plate (606) is movably arranged in a movable groove (605) and is connected with a telescopic oil cylinder (608) through a coupler (607).

4. The electrode regulation system of a ladle refining furnace according to any one of claims 1 to 3, characterized by comprising the following control methods:

1) electrode installation: controlling the three lifting oil cylinders to ascend to the highest position and controlling the three telescopic oil cylinders to extend to the maximum position, waiting for an operator to install the three electrodes on the movable clamp, controlling the three telescopic oil cylinders to contract, and reliably fixing the three electrodes;

2) electrifying the electrode: closing a vacuum switch and an isolating switch in a main loop of a transformer power supply, and disconnecting a grounding switch of the transformer;

3) descending the electrode and starting arc: the electrode adjusting system of the ladle refining furnace sends a downward operation command to three lifting cylinders, the three electrodes move downward, and the electrode adjusting system of the ladle refining furnace detects the actual voltage values of the three electrodes in real time:

when the actual voltage values of the three electrodes are not zero, the three electrodes continuously move downwards until electric arcs are generated;

when the actual voltage value of one electrode is zero, the corresponding electrode stops moving downwards, and enters a waiting state after being withdrawn upwards to a waiting distance, and other electrodes continue to move downwards until an electric arc is generated;

4) automatic control of electrode lifting: after the electric arc is generated, the electrode adjusting system of the ladle refining furnace automatically adjusts the lifting height of the three-phase electrode by adopting an impedance adjuster;

5) and (3) powering off the electrode: after heating is finished, a vacuum switch and an isolating switch in a main loop of a transformer power supply are disconnected, and a grounding switch of the transformer is closed;

6) electrode rising: controlling the three lifting oil cylinders to move upwards, and moving the three electrodes upwards until the three electrodes move to the highest point;

7) electrode station adjustment: and (4) controlling the work of the station adjusting device, driving the rotary base frame, the base, the lifting device, the cross arm, the clamping device and the electrode to integrally rotate to a new station by the station adjusting device, and repeating the steps 2 to 7.

5. The method of claim 4, wherein the station adjustment device has two to three operating positions, each operating position being 90 ° apart.

6. The method of claim 4, wherein the impedance adjuster comprises a set impedance calculation correction unit, an actual impedance sampling calculation unit, and an impedance adjustment control output unit, wherein:

the set impedance calculation and correction unit acquires a basic impedance set value according to an electric arc heating power supply system model, and superimposes a gear switch gear-shifting protection impedance increasing correction, an arc starting slag reducing impedance correction and an impedance set value amplitude limiting link to obtain a final impedance set value actually participating in control;

the actual impedance sampling calculation unit carries out scale transformation, coefficient correction and filtering processing on the secondary voltage and secondary current signals which are actually acquired, then divides the two signals, and the quotient of the two signals is filtered and limited to obtain an actual impedance value which actually participates in control;

and the impedance control deviation is obtained according to the impedance set value and the impedance actual value, the impedance control deviation is automatically adjusted and controlled by a proportional coefficient self-adaptive PI controller, an overcurrent feedforward controller and a short circuit feedforward controller, and the impedance control deviation is output to drive a hydraulic proportional valve after the proportional valve hydraulic characteristic compensation, manual control, pilot valve control and filter links are carried out, so that the lifting of the electrode upright column is controlled, and the purposes of stable arc combustion and uniform heating are achieved.

7. The method of claim 4, wherein the impedance adjuster adjusts the set current value in real time based on the optimal operating point of the refining furnace in the power circle diagram, so that the arc current rapidly reaches a new equilibrium point with the change of the furnace conditions and the electrode is kept stable.

8. The method of claim 7, wherein the determination of the optimal operating point of the finer of the power circle diagram comprises the steps of:

1) data acquisition: selecting the total time length for 15 minutes after the arcing is finished, setting the current to be stably constant from 40KA to 70KA every 10 seconds, and marking the working point at each moment on the power circular diagram;

2) and (3) data calculation: arranging the current values selected by the envelope curve at the point where the current values are most concentrated within 0-900 seconds and every 10 seconds by using a computer, namely the actual minimum average value of the current, the actual maximum average value of the current and the power factor value, and simultaneously calculating the negative deviation and the positive deviation of the current and the current set value;

3) and (3) screening data: comparing the actual current value with the set current value, selecting the current range with the current value fluctuation rate of 5 percent or less and the power factor of 0.67 percent or more as the optimal working point of the refining furnace.

Technical Field

The invention belongs to the technical field of electric furnace control, and particularly relates to an electrode adjusting system of a ladle refining furnace.

Background

The ladle refining furnace is the main external refining equipment in steel production, and is an elegant one after the metallurgy industry due to simple equipment, low investment cost, flexible operation and good refining effect, and is widely applied and developed at home and abroad. The ladle refining furnace mainly uses white slag in a barrel, and argon is blown into the barrel to stir in a low-oxygen atmosphere (the oxygen content is 5 percent), and molten steel passing through a primary refining furnace is heated by a graphite electrode to be refined. Because the argon stirring accelerates the chemical reaction between slag and steel, and the electric arc heating is used for temperature compensation, the longer refining time can be ensured, thereby reducing the oxygen and sulfur contents in the steel. The ladle refining furnace can be matched with an electric furnace to replace the reduction period of the electric furnace, and can also be matched with an oxygen converter to produce high-quality alloy steel.

However, the prior refining furnace structure has the following technical problems:

1) in the operation process of the refining furnace, the height of the electrode needs to be frequently adjusted, the three-phase electrode of the existing partial refining furnace structure cannot be independently adjusted, even if the three-phase electrode of the partial refining furnace structure can be independently adjusted, the verticality and the strength of the three-phase electrode are low, and the situation of shaking is easy to occur in the use process;

2) in the process of heating the steel ladle, the refining furnace generally adopts a 'one-furnace-one-ladle' structure, and when the steel ladle is in the links of transportation, fixation, installation and the like, the refining furnace can start heating only after the steel ladle is ready, so that a large amount of working time is wasted;

3) at present, mature electrode regulators of a refining furnace comprise a constant impedance regulator, a constant power regulator, a three-phase power balance regulator, a constant arc length regulator and the like, and a mainstream electrode regulation control algorithm comprises an arc flow method and an impedance method: the former takes keeping the furnace variable secondary current constant as a control target, and the latter takes keeping the furnace variable secondary load impedance constant as a control target, however, the electrode regulator generally works according to a static impedance set value, but in actual production, the optimal working point of the circuit and the actual state of the circuit and many relations exist, and the electrode regulator using only a static design point can not meet the requirement of optimal operation of the power circuit.

Disclosure of Invention

Aiming at the technical problem, the invention provides an electrode adjusting system of a ladle refining furnace, wherein a lifting device adopts an independent scheme, the free lifting of each electrode upright column can be realized, and a station adjusting device can realize the integral rotation of the electrode upright columns so as to realize the uninterrupted continuous heating of a plurality of ladles; the software part of the arc furnace electrode adjusting system adopts an impedance control strategy, and the electrode state can be automatically adjusted according to the optimal working point preselected by the power circular diagram.

The invention solves the problems through the following technical means:

the utility model provides a ladle refining furnace electrode governing system which characterized in that, includes rotating bed frame, base, elevating gear, station adjusting device, xarm and clamping device, wherein: the rotary base frame serving as a bearing main body is rotatably arranged on the base platform, three upper through holes are formed in the upper side of the rotary base frame, a plurality of upper guide wheels are symmetrically arranged around the upper through holes, three lower through holes are correspondingly formed in the lower side of the rotary base frame, and a plurality of lower guide wheels are symmetrically arranged around the lower through holes; the base is arranged at the bottom of the rotary base frame and used for mounting the lifting device, the base comprises two groups of double-headed hinging seats, four groups of mounting arms and a horizontal mounting seat, the two groups of double-headed hinging seats are symmetrically mounted at the bottom of the rotary base frame, one ends of the mounting arms are hinged on the double-headed hinging seats, the other ends of the mounting arms are fixed on the horizontal mounting seat, and reinforcing beams are arranged between the mounting arms; the lifting device comprises three groups of lifting oil cylinders, a lifting platform, lifting columns, a lifting sleeve and a connecting seat, wherein the bottoms of the lifting oil cylinders are fixed on a horizontal mounting seat, the lifting platform is arranged on a telescopic rod of the lifting oil cylinders, the lifting columns are coaxially arranged inside the lifting sleeve, the bottoms of the lifting columns are arranged on the lifting platform, a connecting platform is arranged at the tops of the lifting columns, the connecting platform is rotatably arranged in a hinged hole of the lifting sleeve through a hinged shaft, a plurality of guide plates matched with guide wheels to work are arranged on the side wall of the lifting sleeve, and the tops of the lifting sleeves are connected with a transverse arm through the connecting seat; the station adjusting device comprises a sliding rail, a pulley, a rotating shaft seat and a rotary driving device, wherein the pulley is arranged at the bottom of the rotating base frame and is matched with the sliding rail to realize fixed-track movement; one end of the cross arm is connected with a clamping device for fixing the electrode, and the other end of the cross arm is connected with a cable.

Preferably, the cross arms include a first cross arm, a second cross arm and a third cross arm which are horizontally and parallelly arranged, the first cross arm and the third cross arm are symmetrically arranged, the tail ends of the first cross arm and the third cross arm are inclined outwards by an angle alpha, the tail end of the second cross arm is inclined downwards by an angle alpha, and the angle alpha ranges from 90 degrees to 150 degrees.

Preferably, the number of the clamping devices is three, the three clamping devices are respectively arranged at the tail ends of the cross arms, the first clamping device is vertically arranged at the tail end of the first cross arm, the second clamping device is horizontally arranged at the tail end of the second cross arm, and the third clamping device is vertically arranged at the tail end of the third cross arm, wherein: clamping device's centre gripping casing end is provided with arc grip slipper and removal clamp, and arc grip slipper and removal clamp cooperation work are used for fixed electrode, and the outer wall and the conductor wire contact of removal clamp, the both ends setting of removing the clamp are on the driving plate, and the driving plate mobilizable install at the shifting chute, and through the flexible hydro-cylinder of coupling joint.

The electrode adjusting system of the ladle refining furnace comprises the following control methods:

1) electrode installation: controlling the three lifting oil cylinders to ascend to the highest position and controlling the three telescopic oil cylinders to extend to the maximum position, waiting for an operator to install the three electrodes on the movable clamp, controlling the three telescopic oil cylinders to contract, and reliably fixing the three electrodes;

2) electrifying the electrode: closing a vacuum switch and an isolating switch in a main loop of a transformer power supply, and disconnecting a grounding switch of the transformer;

3) descending the electrode and starting arc: the electrode adjusting system of the ladle refining furnace sends a downward operation command to three lifting cylinders, the three electrodes move downward, and the electrode adjusting system of the ladle refining furnace detects the actual voltage values of the three electrodes in real time:

when the actual voltage values of the three electrodes are not zero, the three electrodes continuously move downwards until electric arcs are generated;

when the actual voltage value of one electrode is zero, the corresponding electrode stops moving downwards, and enters a waiting state after being withdrawn upwards to a waiting distance, and other electrodes continue to move downwards until an electric arc is generated;

4) automatic control of electrode lifting: after the electric arc is generated, the electrode adjusting system of the ladle refining furnace automatically adjusts the lifting height of the three-phase electrode by adopting an impedance adjuster;

5) and (3) powering off the electrode: after heating is finished, a vacuum switch and an isolating switch in a main loop of a transformer power supply are disconnected, and a grounding switch of the transformer is closed;

6) electrode rising: controlling the three lifting oil cylinders to move upwards, and moving the three electrodes upwards until the three electrodes move to the highest point;

7) electrode station adjustment: and (4) controlling the work of the station adjusting device, driving the rotary base frame, the base, the lifting device, the cross arm, the clamping device and the electrode to integrally rotate to a new station by the station adjusting device, and repeating the steps 2 to 7.

Preferably, the station adjusting device has two to three working positions, each working position being separated by 90 °.

Preferably, the impedance adjuster includes a set impedance calculation and correction unit, an actual impedance sampling calculation unit, and an impedance adjustment control output unit, wherein:

the set impedance calculation and correction unit acquires a basic impedance set value according to an electric arc heating power supply system model, and superimposes a gear switch gear-shifting protection impedance increasing correction, an arc starting slag reducing impedance correction and an impedance set value amplitude limiting link to obtain a final impedance set value actually participating in control;

the actual impedance sampling calculation unit carries out scale transformation, coefficient correction and filtering processing on the secondary voltage and secondary current signals which are actually acquired, then divides the two signals, and the quotient of the two signals is filtered and limited to obtain an actual impedance value which actually participates in control;

and the impedance control deviation is obtained according to the impedance set value and the impedance actual value, the impedance control deviation is automatically adjusted and controlled by a proportional coefficient self-adaptive PI controller, an overcurrent feedforward controller and a short circuit feedforward controller, and the impedance control deviation is output to drive a hydraulic proportional valve after the proportional valve hydraulic characteristic compensation, manual control, pilot valve control and filter links are carried out, so that the lifting of the electrode upright column is controlled, and the purposes of stable arc combustion and uniform heating are achieved.

Preferably, the impedance regulator real-time trims the set current value based on the optimal operating point of the refining furnace of the power circular diagram, so that the arc current rapidly reaches a new balance point along with the change of the furnace condition and the stability of the electrode is kept. Specifically, the determination of the optimum operating point of the refining furnace of the power circle diagram comprises the following steps:

1) data acquisition: in the well-penetrating period after the arcing is finished, the total time is selected for 15 minutes, the current is set to be increased from 40KA every 10 seconds to 0.5KA until the current is stably increased to 70KA, and the working point at each moment is marked on the power circular diagram;

2) and (3) data calculation: arranging the current values selected by the envelope curve at the point where the current values are most concentrated within 0-900 seconds and every 10 seconds by using a computer, namely the actual minimum average value of the current, the actual maximum average value of the current and the power factor value, and simultaneously calculating the negative deviation and the positive deviation of the current and the current set value;

3) and (3) screening data: comparing the actual current value with the set current value, selecting the current range with the current value fluctuation rate of 5 percent or less and the power factor of 0.67 percent or more as the optimal working point of the refining furnace.

The electrode adjusting system of the ladle refining furnace has the following beneficial effects:

1) the novel lifting device is adopted, the lifting column and the lifting sleeve are hinged, meanwhile, the rotating base frame guide wheel is arranged, the guide plate is arranged on the outer surface of the lifting sleeve, and the guide plate is matched with the upper through hole, the lower through hole and the upper guide wheel and the lower guide wheel to work, so that on one hand, the independent adjustment of a three-phase electrode can be realized, on the other hand, higher perpendicularity and installation strength can be kept, shaking is not easy to occur in the use process, and the lifting height is accurate.

2) The invention adopts a rotatable multi-station structure, the station adjusting device has two to three working positions, each working position is separated by 90 degrees, the refining furnace realizes the technical effect of one furnace and multiple ladles in the process of heating the ladles, after the ladles are heated, the adjacent ladles are directly heated, the refining furnace does not need to wait for the ready ladles to start heating, and a great deal of working time is saved.

3) The cross arm and the clamping device adopt novel structures, the tail ends of the first cross arm and the third cross arm are symmetrically bent outwards, and the tail end of the second cross arm is bent downwards to form a staggered structure.

4) The invention adopts the arcing control strategy of 'flush waiting', avoids that a certain electrode directly touches the material body to be heated when the electrode descends too fast in the mechanical motion, on one hand, the electrode can be prevented from being broken, on the other hand, the error of a mechanical transmission part can be compensated, and the smooth arcing is ensured.

5) The electrode regulation algorithm based on impedance control assists with the proportional coefficient self-adaption function of the regulator, improves the stability and sensitivity of electrode regulation, and the feedforward deviation rectifying action of over-current control and short-circuit control can quickly and effectively reduce the interference of the factors such as argon blowing, feeding, wire feeding and the like which can not be directly measured on stable combustion of electric arc.

6) The invention adopts the impedance control strategy in the software part of the arc furnace electrode adjusting system, can automatically adjust the electrode state according to the optimal working point preselected by the power circular diagram, can quickly stabilize the electrode, avoid frequent lifting, save energy consumption, improve production efficiency, reduce interference on a power grid, and solve the technical problem that the electrode adjuster cannot meet the optimized operation of a power circuit by combining dynamic and static technical indexes.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic view of a rotary base frame according to the present invention;

FIG. 3 is a schematic view of the structure of a guide wheel according to the present invention;

FIG. 4 is a schematic view of a base structure according to the present invention;

FIG. 5 is a schematic view of the lifting device of the present invention;

FIG. 6 is a schematic view of the lift cylinder structure of the present invention;

FIG. 7 is a schematic view of the construction of the lift sleeve of the present invention;

FIG. 8 is a schematic view of the lifting column of the present invention;

FIG. 9 is a schematic view of a station adjustment apparatus according to the present invention;

FIG. 10 is a schematic view of a cross arm structure according to the present invention;

FIG. 11 is a schematic view of a cross arm layout according to the present invention;

FIG. 12 is a schematic view showing an external structure of the holding jig of the present invention;

fig. 13 is a schematic view of the internal structure of the holding device of the present invention.

Wherein, 1-rotating pedestal, 101-upper through hole, 102-upper guide wheel, 103-lower through hole, 104-lower guide wheel, 2-base, 201-double-head hinged seat, 202-mounting arm, 203-horizontal mounting seat, 204-reinforcing beam, 3-lifting device, 301-lifting oil cylinder, 302-lifting platform, 303-lifting column, 304-lifting sleeve, 305-connecting seat, 3031-connecting platform, 3032-articulated shaft, 3041-articulated hole, 3042-guide plate, 4-station adjusting device, 401-sliding rail, 402-pulley, 403-rotating shaft seat, 5-cross arm, 501-first cross arm, 502-second cross arm, 503-third cross arm, 6-clamping device, 601-clamping shell, 602-arc clamping seat, 603-movable clamp, 604-electric lead, 605-movable groove, 606-transmission plate, 607-coupler, 608-telescopic oil cylinder, 7-electrode and 8-cable.

Detailed Description

In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

The present invention will be described in detail below with reference to the accompanying drawings.

Example one

As shown in fig. 1 to 3, the electrode adjusting system for a ladle refining furnace includes a rotating base frame 1, a susceptor 2, a lifting device 3, a station adjusting device 4, a cross arm 5, and a clamping device 6, wherein: the rotary pedestal 1 is rotatably installed on a foundation platform as a bearing main body, the foundation platform is a cement structure or a frame base, three upper through holes 101 are formed in a bearing plate on the rotary pedestal 1, a plurality of upper guide wheels 102 are symmetrically arranged around the upper through holes 101, three lower through holes 103 are correspondingly formed in a lower bearing plate of the rotary pedestal 1, and a plurality of lower guide wheels 104 are symmetrically arranged around the lower through holes 103. Specifically, the upper through hole 101 and the lower through hole 103 are correspondingly arranged and used for vertically installing the lifting sleeve 304, four to eight guide wheels are arranged in each through hole, the guide wheels are symmetrically arranged and used for guiding the lifting sleeve 304 to vertically move, and good perpendicularity can be ensured by double-row fixing and supporting.

Example two

As shown in fig. 1 and 4, the base 2 is disposed at the bottom of the rotating pedestal 1 and is used for installing the lifting device 3, the base 2 includes two sets of double-headed hinge seats 201, four sets of installation arms 202 and a horizontal installation seat 203, the two sets of double-headed hinge seats 201 are parallel and symmetrically installed at the bottom of the rotating pedestal 1, one end of the installation arm 202 is hinged on the double-headed hinge seat 201, the other end of the installation arm 202 is fixed on the horizontal installation seat 203, a reinforcing beam 204 is disposed between the installation arms 202, the four installation arms 202 and the horizontal installation seat 203 form a swingable frame structure for eliminating errors occurring in the installation process and avoiding movement interference, and at the same time, it is ensured that the horizontal installation seat 203 is always horizontal under the action of gravity and can rotate along with the rotating pedestal 1.

EXAMPLE III

As shown in fig. 5 to 8, the lifting device 3 includes three sets of lifting cylinders 301, a lifting platform 302, a lifting column 303, a lifting sleeve 304 and a connecting seat 305, specifically, the lifting cylinders 301 are controlled by hydraulic valves, the bottom of the lifting cylinders 301 is fixed on the horizontal mounting seat 203, the lifting platform 302 is disposed on telescopic rods of the lifting cylinders 301, the lifting platform 302 can move along with the telescopic rods, the lifting column 303 is coaxially disposed inside the lifting sleeve 304, the bottom of the lifting column 303 is mounted on the lifting platform 302 through flanges, the top of the lifting column 303 is hinged, specifically, the top of the lifting column 303 is provided with a connecting platform 3031, the connecting platform 3031 is rotatably mounted in a hinge hole 3041 of the lifting sleeve 304 through a hinge shaft 3032, and the lifting platform 302, the lifting column 303, the lifting sleeve 304 and the connecting seat 305 are driven to move when the lifting cylinders 301 move.

It should be noted that a plurality of guide plates 3042 cooperating with the guide wheels are disposed on the side walls of the lifting sleeve 304, the guide plates 3042 are in a V-shaped structure, and are reversely buckled on the side walls of the lifting sleeve 304, and the planes on the two sides of the V-shaped structure are used for clinging to the rolling surfaces of the guide wheels.

Example four

As shown in fig. 1 and 9, the station adjusting device 4 includes a sliding 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 rotating base frame 1 and cooperates with the sliding rail 401 to realize fixed-track movement, the sliding rail 401 is laid on the base platform, the top of the rotating shaft seat 403 is installed at the bottom center position of the rotating base frame 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 an electric motor or a hydraulic motor, and the electric motor or the hydraulic motor transmits torque to the rotating shaft seat 403 through a speed reducer. It should be noted that the station adjusting device has two to three working positions, each working position is separated by 90 °, at this time, the slide rail 401 may adopt a 180 ° rail or a 270 ° rail, etc., the separated angle of the stations should also be related to the actual ladle size, and a plurality of stations may be flexibly set, and are spaced at equal intervals of 30 ° to 60 °.

EXAMPLE five

As shown in fig. 10 and 11, a holding device 6 for fixing the electrode 7 is connected to one end of the cross arm 5, and a cable 8 is connected to the other end of the cross arm 5. Specifically, the cross arm 5 comprises a first cross arm 501, a second cross arm 502 and a third cross arm 503 which are horizontally and parallelly arranged, the first cross arm 501 and the third cross arm 503 are symmetrically arranged, the tail ends of the first cross arm 501 and the third cross arm 503 are inclined outwards by an angle alpha, the tail end of the second cross arm 502 is inclined downwards by an angle alpha, the angle alpha ranges from 90 degrees to 150 degrees, the angle alpha is preferably 120 degrees, the tail ends of the first cross arm and the third cross arm are symmetrically bent outwards, and the tail end of the second cross arm is bent downwards to form a staggered structure.

EXAMPLE six

As shown in fig. 12 and 13, the number of the clamping devices 6 is three, three clamping devices 6 are respectively installed at the ends of the cross arm 5, a first clamping device is vertically installed at the end of the first cross arm 501, a second clamping device is horizontally installed at the end of the second cross arm 502, a third clamping device is vertically installed at the end of the third cross arm 503, specifically, an arc-shaped clamping seat 602 and a movable clamp 603 are arranged at the end of a clamping housing 601 of the clamping device 6, the arc-shaped clamping seat 602 and the movable clamp 603 work in cooperation for fixing the electrode 7, the outer wall of the movable clamp 603 is in contact with an electric lead 604, two ends of the movable clamp 603 are arranged on a transmission plate 606, the transmission plate 606 is movably installed in a movable groove 605 and is connected with a telescopic cylinder 608 through a coupling 607, and it should be noted that the automatic operation of the clamping device 6 can be realized by controlling the. Specifically, the electrode clamping and releasing are realized through a hydraulic cylinder, and can be carried out at any height of the upright post.

EXAMPLE seven

The electrode regulating system of the ladle refining furnace comprises the following control method, and the following steps do not comprise the conventional steps of electrode replacement, electrode extension and the like.

1) Electrode installation: controlling the three lifting oil cylinders to ascend to the highest position and controlling the three telescopic oil cylinders to extend to the maximum position, waiting for an operator to install the three electrodes on the movable clamp, controlling the three telescopic oil cylinders to contract, and reliably fixing the three electrodes;

specifically, when an operator operates and installs the three electrodes, the bottoms of the three electrodes are aligned as much as possible.

2) Electrifying the electrode: closing a vacuum switch and an isolating switch in a main loop of a transformer power supply, and disconnecting a grounding switch of the transformer;

3) descending the electrode and starting arc: the electrode adjusting system of the ladle refining furnace sends a downward operation command to three lifting cylinders, the three electrodes move downward, and the electrode adjusting system of the ladle refining furnace detects the actual voltage values of the three electrodes in real time:

when the actual voltage values of the three electrodes are not zero, the three electrodes continuously move downwards until the electric arc is generated, and specifically, the actual voltage values of the three electrodes are not zero, which indicates that the three electrodes stably descend at the moment, and no electrode descends too fast.

When the actual voltage value of one electrode is zero, the corresponding electrode stops moving downwards, and enters a waiting state after being withdrawn upwards to a waiting distance, and other electrodes continue to move downwards until an electric arc is generated; specifically, the waiting distance is generally 5-10 cm, when the actual voltage value of one electrode is zero, the electrode descends too fast and contacts the furnace body, and a 'flush waiting' program is started, so that the electrode can be prevented from being broken, errors of a mechanical transmission part can be compensated, and smooth arcing is ensured.

Specifically, the precise position control of the lift cylinder is performed by existing equipment, and a position sensor or a high-precision hydraulic control valve can be configured, for example: a pull-string encoder or a resistance ruler.

4) Automatic control of electrode lifting: after the electric arc is generated, the electrode adjusting system of the ladle refining furnace automatically adjusts the lifting height of the three-phase electrode by adopting an impedance adjuster;

in particular, the impedance adjuster may employ existing techniques and devices, such as: siemens' S7-300, 400, 1500 series, or ControlLogix RSLogix5000 series PLCs, finer resistance includes contact resistance from transformer to electrode, finer reactance is caused by wiring between short net three phase cables, which changes with the elevation position of the electrode. In the smelting process, the electrode electric arc is resistive, the resistance value of the electric arc resistance is changed along with the length of the electric arc, and the length of the electric arc is adjusted by the lifting of the electrode. And comparing the actual value with the corrected value, outputting an impedance deviation value, driving a servo valve through a power amplifier, and controlling the electrode to ascend or descend so as to realize the adjustment of the impedance.

5) And (3) powering off the electrode: after heating is finished, a vacuum switch and an isolating switch in a main loop of a transformer power supply are disconnected, and a grounding switch of the transformer is closed;

6) electrode rising: controlling the three lifting oil cylinders to move upwards, and moving the three electrodes upwards until the three electrodes move to the highest point;

7) electrode station adjustment: and (4) controlling the work of the station adjusting device, driving the rotary base frame, the base, the lifting device, the cross arm, the clamping device and the electrode to integrally rotate to a new station by the station adjusting device, and repeating the steps 2 to 7. Specifically, the station adjusting device has two to three working positions, and each working position is separated by 90 degrees.

Example eight

In this embodiment, the impedance adjuster not only can adopt the prior art and the equipment, but also can adopt a novel impedance controller, and the stability and the sensitivity of electrode adjustment are improved through control means such as impedance feedback control, overcurrent feedforward control and short circuit feedforward control. Specifically, the impedance adjuster includes a set impedance calculation and correction unit, an actual impedance sampling calculation unit, and an impedance adjustment control output unit.

Specifically, the set impedance calculation and correction unit obtains a basic impedance set value according to an electric arc heating power supply system model, and superimposes a gear switch gear-shifting protection impedance increasing correction, an arc starting slag reducing impedance correction and an impedance set value amplitude limiting link to obtain a final impedance set value actually participating in control; the actual impedance sampling calculation unit performs scale transformation, coefficient correction and filtering processing on the secondary voltage and secondary current signals which are actually acquired, then divides the two signals, and the quotient of the two signals is filtered and limited to obtain an actual impedance value which actually participates in control; the impedance control deviation is obtained according to the impedance set value and the impedance actual value, the impedance control deviation is automatically adjusted and controlled by a proportional coefficient self-adaptive PI controller, an overcurrent feedforward controller and a short circuit feedforward controller, and the impedance control deviation is output to drive a hydraulic proportional valve after the proportional valve hydraulic characteristic compensation, manual control, pilot valve control and filter links are carried out, so that the lifting of the electrode upright column is controlled, and the purposes of stable arc combustion and uniform heating are achieved.

It should be noted that, in combination with the heating equivalent circuit and the transformer stable operation boundary conditions, a "power circular diagram" of the reactive power-active power corresponding relationship may be generated by computer software, and the positions of the shift switches under different power factors and corresponding impedance setting values constrained by the boundary conditions are stored in a memory data block of the electrode adjusting system in the form of a matrix table, so as to be selected by an operator as the basic impedance setting values for electrode adjustment.

Example nine

In this embodiment, the impedance adjuster can trim the set current value in real time based on the optimal operating point of the refining furnace of the power circular diagram, so that the arc current rapidly reaches a new balance point along with the change of the furnace condition and the stability of the electrode is maintained, specifically, the determination of the optimal operating point of the refining furnace of the power circular diagram includes the following steps:

1) data acquisition: the total time length is selected for 15 minutes after the arcing is finished, the current is set to be increased from 40KA to 70KA constantly every 10 seconds, the mean value working point in one current time period is displayed at each moment of 1s on the power circle diagram, specifically, the mean value in one current time period is displayed at 1s, and meanwhile, the longer the selection time is, the more accurate the data is, but the longer the calculation time is, the time is generally 15-20 minutes.

2) And (3) data calculation: arranging the current values selected by the envelope curve at the point where the current values are most concentrated within 0-900 seconds and every 10 seconds by using a computer, namely the actual minimum average value of the current, the actual maximum average value of the current and the power factor value, and simultaneously calculating the negative deviation and the positive deviation of the current and the current set value; specifically, the data acquisition interval of 10s may be adjusted to 0.05, 0.1, or 1 second, etc., according to the computer computing power.

3) And (3) screening data: comparing the actual current value with the set current value, selecting the current range with the current value fluctuation rate of 5 percent or less and the power factor of 0.67 percent or more as the optimal working point of the refining furnace. It should be noted that, by determining the optimum operating point of the refining furnace by the above method, the system can correct the set current value according to the record and learning of the previous multiple furnaces, thereby rapidly making the arc current reach a new balance point along with the change of the furnace condition and keeping the electrode stable.

The invention provides an electrode adjusting system of a ladle refining furnace, wherein a lifting device of the electrode adjusting system adopts an independent scheme, free lifting of each electrode upright column can be realized, and a station adjusting device can realize integral rotation of the electrode upright columns so as to realize uninterrupted continuous heating of a plurality of ladles; the software part of the arc furnace electrode adjusting system adopts an impedance control strategy, and the electrode state can be automatically adjusted according to the optimal working point preselected by the power circular diagram.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.