JP3589084B2 - Electrode weight measurement device for arc furnace - Google Patents

Description

【００２６】
表１より、本発明に係る方法で測定した電極重量は、精度の良いクレーンによる測定値と良く一致しており、本発明に係る装置で正確な測定が行なわれることが明らかである。また、本発明に係る装置での測定では、３本の電極の重量を同時に測定でき、その測定時間は、平均３０分であった。従って、１本毎に測定する従来のクレーン利用方法に比較して、測定時間の大幅な短縮ができることも明らかである。
【００２７】
【発明の効果】
以上述べたように、本発明により、危険なオペレータの炉上作業が解消でき、且つ短時間で、しかも精度良くアーク炉用電極の重量測定が可能となる。
【図面の簡単な説明】
【図１】本発明に係る電極重量の測定装置を示す概略図である。
【図２】本発明に係る電極重量の測定装置の詳細を示す図である。
【図３】従来の電極重量の測定方法を説明する図であり、（ａ）はアーク炉の縦断面を、（ｂ）はクレーンでの測定状態を示す。
【図４】本発明に係る電極重量の測定装置で採用した電極受台部分の詳細を説明する図であり、（ａ）は側面を、（ｂ）は平面を示す。
【符号の説明】
１ オペレータ
２ アーク炉
３ 炉蓋
４ 電極
５ 治具
６ 電極ホルダ
７ クランプ部
８ クレーン
９ 電極ホルダ支持柱
１０ 旋回手段
１１ 電極受台（受台）
１２ 電極支承体（支承体）
１３ 重量検出器（ロードセル）
１４ 緩衝手段
１５ 作業床
１６ 昇降手段
１７ カーボンプレート
１８ 一体型プレート
１９ リミットスイッチ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a device for measuring the weight of an electrode for an arc furnace, and more particularly to a technique for quickly and accurately measuring the electrode weight of an arc furnace used for refining metal such as steel, ferromagnetic iron, and silicon.
[0002]
[Prior art]
Arc furnaces used for refining metals such as steel, ferro-alloy or silicon are usually arc-discharged between a plurality of graphite electrodes inserted into the furnace from above the furnace, or graphite electrodes inserted into the furnace from above the furnace. And an arc discharge between the metal and the metal to be melted, produced or refined to generate high heat, and the heat is used to dissolve the metal or ore or to produce or refine the metal. Graphite electrodes are usually used for the upper electrode of such an arc furnace, but they are vaporized by arc heat during operation, or oxidized and consumed by a high-temperature atmosphere or slag.
[0003]
Since this graphite electrode is expensive, it is desired to operate the arc furnace under appropriate conditions to minimize wear. For that purpose, each time the operation of each charge is completed, it is necessary to accurately measure the consumption of the electrode and reflect it in the operation of the next charge.
[0004]
Heretofore, such electrode weight measurement has been performed using the operation stop time of the electric furnace or intentionally stopping the operation of the electric furnace. That is, as shown in FIG. 3A, after the operator 1 climbs on the furnace lid 3 of the arc furnace 2, mounts the jig 5 on the upper part of the electrode 4 and unclamps the clamp part 7 of the electrode holder 6, The electrode 4 was hoisted up by a crane 8 and weighed by a weighing machine (not shown) of the crane 8 (see FIG. 3B). Although this method has an advantage that the weight of the electrode 4 can be accurately measured, the operator 1 has to work on the furnace lid 3 with high heat, and the work load is large. In addition, since it takes a long time to attach and detach the jig 5 to and from the upper part of the electrode and to lift it by the crane 8, the electrode 4 is oxidized and consumed during that time, and the downtime (operation stop time) is long. There were problems such as the inability to raise the operating rate.
[0005]
In order to solve such a problem, Japanese Patent Application Laid-Open No. 2-306137 discloses a method in which an electrode placed in an arc furnace is held by an electrode holder and the weight is measured with a weight detector (actually, tension is measured). ), And subtracting a known weight of only the electrode holder from the measured value to measure the weight of the electrode. According to this method, the workload of the operator is significantly reduced, and the time required for weighing is also significantly reduced.
[0006]
However, this method also has the following problems, and has been difficult to put into practical use. That is,
(1) In order to measure the weight by integrating the electrode and the electrode holder, it is necessary to use a weight detector whose full scale is much larger than the weight of the electrode itself. Large error,
(2) Since the measurement is performed with the power supply cable attached, the slack state of the power supply cable increases the error of the measured value.
(3) Dust and metal rising from the gap between the electrode of the arc furnace and the electrode accumulate on the electrode support, which causes a measurement error.
[0007]
[Problems to be solved by the invention]
In view of such circumstances, an object of the present invention is to propose a method and apparatus for measuring the weight of an electrode for an arc furnace, which can eliminate dangerous operations on the furnace by an operator, and can perform measurement in a short time and with high accuracy. I have.
[0008]
[Means for Solving the Problems]
The inventor worked diligently to develop a new measurement technique in order to solve the above-mentioned problems, and completed the result as the present invention.
[0009]
That is, the present invention provides an arm-shaped electrode holder that clamps an electrode and holds the electrode vertically, an electrode holder supporting column that supports the electrode holder in a horizontal posture, and an electrode holder that centers on the axis of the supporting column. An electrode support for receiving an end of an electrode opened by an unclamping of an electrode holder at a position outside the furnace where the electrode is moved out of the furnace. And a weight sensor for detecting the weight of the electrode on the electrode support body.
[0010]
Also, the present invention provides a method in which a weight sensor is installed under the electrode support or the number of the weight sensors is set to three, and each sensor is formed in a triangular shape surrounding a central axis of the electrode support in a plan view. It is a weight measuring device for an electrode for an arc furnace, which is arranged at a vertex.
[0011]
Further, the present invention provides a weight measuring apparatus for an electrode for an arc furnace, wherein the electrode support body has at least an upper surface formed of a carbon plate or has a spherical seat. is there.
[0012]
In addition, the present invention provides an electrode for an arc furnace, wherein an impact buffer is provided below the electrode support, or the electrode support and the weight sensor are mounted on a lifting means. It is also a weight measuring device.
[0013]
According to the present invention, even if a plurality of electrodes are arranged in the arc furnace, the weight of each electrode can be measured simultaneously and in a state where the electrodes are opened from the electrode holder, so that the weight is faster and more accurate than in the past. Measurement is possible.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
First, the electrode targeted by the present invention is not a so-called "Sederberg electrode" which is self-burning, but a graphite electrode which is fired in advance. As an arc furnace using such an electrode, a three-phase AC type having three upper electrodes (graphite electrodes), a direct current having one upper electrode (graphite electrode) and one or more furnace bottom electrodes. There are many formulas.
[0016]
In these arc furnaces 2, as shown in FIG. 3A, the electrode 4 has an arm-shaped electrode holder 6 that clamps the electrode 4 and holds the electrode 4 vertically, and the electrode holder 6 can be moved up and down in a horizontal posture. Generally, an electrode device including an electrode holder supporting column 9 to be supported and a turning means 10 for turning the electrode holder 6 about the axis of the supporting column 9 and moving the electrode to the outside of the furnace is generally used. Then, when charging the raw material into the furnace, the electrode 4 is rotated from the inside of the furnace in advance, and moves to a position outside the furnace (hereinafter, referred to as a movement position outside the furnace). In the present invention, the weight is measured at the moving position outside the furnace by using the retreat time of the electrode 4 inevitably generated in the operation of the arc furnace.
[0017]
That is, in the present invention, as shown in FIG. 1, the electrode receiving base 11 is disposed at the position where the electrode 4 is moved out of the furnace, and the electrode 4 is placed thereon in a free state, that is, released from the electrode holder 6. An electrode support 12 to be placed and a weight detector 13 for detecting the electrode weight are provided. In this electrode weight measuring device, since the electrode 4 is not restrained by an external force, a large measurement error caused by the electrode holder, the power supply cable, and the like caused by the measuring method described in JP-A-2-306137 can be avoided at all. Become like At the time of measurement, the electrode 4 may lean on the clamp portion 7 of the electrode holder 6, but according to the study of the inventor, since the electrode 4 is in a substantially vertical state, a measurement error due to leaning can be ignored. It was small.
[0018]
Usually, the tip of the electrode 4 is tapered by use. For this reason, in the present invention, efforts are made to make the electrode 4 substantially vertical. That is, the electrode support 12 provided on the pedestal 11 of the electrode 4 has a spherical seat at the portion that comes into contact with the electrode tip so that the load is uniformly applied to the support 12 regardless of the shape of the electrode tip. . Further, since the electrode 4 is in a high temperature state, the support body 12 needs to have heat resistance. Further, if the support body 12 is harder than the electrode 4, the electrode may be broken by a shock when the electrode 4 comes into contact with the electrode 4. It is good to provide in. In addition, as shown in FIG. 2, a buffer means 14 such as a spring may be separately provided between the support body 12 and the load cell 13 to reduce the shock.
[0019]
Next, detection of the weight of the electrode 4 can be performed using a known weight sensor such as a load cell, as described above. This is because the load cell 13 is positioned below the support body 12 to accurately detect the weight. Usually, the number of the load cells 13 may be one for each bearing body 12. However, as described above, the tip of the electrode 4 becomes thin or chipped due to wear due to oxidation or evaporation during operation, and is not always in a fixed shape. 12 may be eccentric from the central axis. In such a situation, measuring the electrode weight with a single load cell 13 may possibly cause an error. Therefore, in the present invention, the three load cells 13 are arranged at positions corresponding to the vertices of an equilateral triangle that surrounds the center axis of the support body 12 in plan view, and the weight is measured while being supported at three points. are doing.
[0020]
In order to reduce the number of expensive load cells 13 to be used and to achieve high measurement accuracy, as shown in FIG. When the electrodes 4 are weighed one by one, the weight of one electrode can be measured by three-point support. If the weighed values by the three load cells 13 are summed up, measurement with high accuracy becomes possible.
[0021]
The electrode support 12 and the weight detector 13 may be installed directly on the work floor 15. However, in consideration of workability such as raising and lowering of the electrode 4, in the present invention, it is preferable to provide a receiving table on the work floor 15. By doing so, the vertical movement distance of the electrode 4 can be shortened, and the working time can be shortened and the working can be simplified. It is to be noted that if the height of the pedestal 11 is variable, it is convenient for these operations. Therefore, in the present invention, the pedestal 11 is provided with its own elevating means 16 separately. Specifically, it is preferable to vertically dispose an actuator such as a hydraulic cylinder in terms of structure, but it is not necessarily limited to this. For example, a table lifter may be used. Means for relatively bringing the electrode 4 and the support body 12 close to each other and detecting the contact include monitoring by a TV camera, detection by a limit switch, and detection of a load cell exceeding a certain "threshold". And the like can be preferably used.
[0022]
【Example】
Using a three-phase alternating current arc furnace, low carbon steel was melted. The electrode used was a calcined graphite electrode having an outer diameter of 20 inches, a length of 1800 mm, and a weight of 645 kg / piece. As shown in FIG. 1, three of these electrodes were set on the upper part of the arc furnace while being held by an electrode holder.
[0023]
The raw materials used for one charge operation were 55 tons of iron scrap, other slag-making agents, and deoxidizers. During operation, oxygen gas was also blown into the steel bath surface using a lance. The operation was performed according to the conventional procedure, and during that time, the amount of electricity supplied to the electrodes was changed according to the operation conditions.
[0024]
A large number of such operations were carried out, and the electrode weight was measured with the electrode weight measuring device according to the present invention using the operation stop time after each charge. At that time, the same electrode was separately suspended by a crane and weighed. The results are collectively shown in Table 1.
[0025]
[Table 1]

[0026]
From Table 1, it is clear that the electrode weight measured by the method according to the present invention is in good agreement with the value measured by a high-precision crane, and that the apparatus according to the present invention performs accurate measurement. In the measurement with the device according to the present invention, the weight of three electrodes could be measured simultaneously, and the measurement time was 30 minutes on average. Therefore, it is apparent that the measurement time can be significantly reduced as compared with the conventional crane utilization method in which measurement is performed one by one.
[0027]
【The invention's effect】
As described above, according to the present invention, dangerous operations on the furnace by an operator can be eliminated, and the weight of the arc furnace electrode can be measured accurately in a short time.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an electrode weight measuring device according to the present invention.
FIG. 2 is a diagram showing details of an electrode weight measuring device according to the present invention.
3A and 3B are diagrams illustrating a conventional method for measuring the weight of an electrode, in which FIG. 3A shows a vertical section of an arc furnace, and FIG. 3B shows a measurement state using a crane.
4A and 4B are diagrams illustrating details of an electrode receiving portion used in the electrode weight measuring device according to the present invention, wherein FIG. 4A shows a side surface and FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Operator 2 Arc furnace 3 Furnace lid 4 Electrode 5 Jig 6 Electrode holder 7 Clamp part 8 Crane 9 Electrode holder support pillar 10 Rotating means 11 Electrode receiving stand (receiving stand)
12. Electrode support (support)
13 Weight detector (load cell)
14 buffer means 15 work floor 16 elevating means 17 carbon plate 18 integrated plate 19 limit switch

Claims (7)

An arm-shaped electrode holder that clamps and holds the electrode vertically, an electrode holder support column that supports the electrode holder in a vertical position, and an electrode holder that pivots around the axis of the support column, An electrode device for an arc furnace having a swirling means for moving the outside of the furnace,
An electrode support for receiving the tip of the electrode opened by the unclamping of the electrode holder, and a weight sensor for detecting the weight of the electrode on the electrode support are provided at the position where the electrode moves outside the furnace. Weighing device for arc furnace electrodes. 2. A weight measuring device for an electrode for an arc furnace according to claim 1, wherein a weight sensor is provided below said electrode support. 3. The apparatus according to claim 2, wherein the number of the weight sensors is three, and each of the sensors is arranged at each vertex of a triangle surrounding the central axis of the electrode support in plan view. . The electrode weight measurement device for an arc furnace according to any one of claims 1 to 3, wherein the electrode support body has at least an upper surface formed of a carbon plate. The said electrode support body has a spherical seat, The weight measuring device of the electrode for arc furnaces in any one of Claims 1-3 characterized by the above-mentioned. 6. An apparatus for measuring the weight of an electrode for an arc furnace according to claim 1, wherein an impact buffer is provided below said electrode support. The electrode weight measurement device for an arc furnace according to any one of claims 1 to 6, wherein the electrode support and the weight sensor are mounted on a lifting means.

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