JPH05288477A - Repairing device for metal smelting furnace - Google Patents

Abstract

PURPOSE:To obtain a repairing device for metal smelting furnace, which is capable of saving the consumption of repairing materials and prolonging the life of the furnace, in a repairing controller for continuing the operation of the metal smelting furnace while repairing a damaged area due to excessive fusion. CONSTITUTION:A repairing controller 6 is provided with a control circuit 9 detecting the remaining thickness of refractory detected by a sensor brick 1 buried into the hot spot of a metal smelting furnace 5 beforehand. The control circuit 9 compares the detected remaining thickness T with a predetermined value of remaining thickness and repairs the furnace properly by controlling the operation of a repairing device 10 in accordance with a difference obtained by the comparison whereby the consumption of repairing materials can be saved and the life of the furnace can be prolonged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a repairing device for repairing a erosion damage portion of a refractory lining of a metal melting furnace, and in particular, it is appropriately repaired by a refractory repair material in accordance with the erosion condition of the furnace, and the furnace is used as much as possible. The present invention relates to a repairing device for a metal melting furnace that extends the life of the metal.

[0002]

2. Description of the Related Art Generally, a metal melting furnace represented by an electric furnace whose inner wall surface is covered with refractory such as bricks is
It is unavoidable that the lining brick gradually melts down due to its use. For example, in a region where the heat load due to the furnace body electrode is large (also called a hot spot), the temperature is higher than in other furnace regions, and the melting occurs. Easy to lose.

Therefore, in the conventional use, when the melting degree of the refractory material in the region (hereinafter referred to as the melting region) where the melting loss is likely to occur is advanced and the residual thickness of the refractory material in this region reaches the use limit, the furnace is used. Brick work has been done over the whole area. However, since this method is based on the region with the largest amount of erosion loss, bricks will be replaced over the entire furnace even if bricks of considerable thickness remain in other parts of the furnace. Therefore, there is a problem that the running cost is high because the cost is not economical and the total replacement period is shortened.

In the present situation, for example, a refractory repairing apparatus sometimes blows an irregular shaped refractory onto the excessive melting damage area to repair it, thereby making a difference from the refractory residual thickness in other furnace areas. Is made smaller each time, and the total replacement period is lengthened accordingly.

[0005]

Since the amorphous refractory has a higher unit price per amount of erosion than brick, excessive repair (spraying) is costly. Therefore, when repairing, it is important to accurately grasp the degree of melting damage of the refractory and to repair an appropriate amount in a timely manner. However, under the present circumstances, when the operator visually judges that the excessive erosion region is severely eroded, it is appropriately performed, and the degree of repair thereof largely depends on the intuition of the operator.

Therefore, the amount of the refractory repair material used for each repair does not properly correspond to the erosion condition at that time, and at some time, the entire furnace is refilled with a large amount of repair material and bricks left on the inner wall. However, it is sometimes said that the furnace life is shortened to the maximum extent by locally melting the excessive erosion area and shortening the life due to insufficient repair. Absent.

In view of the present situation described above, the present invention provides a repairing apparatus for a metal melting furnace, which can reduce the amount of repair material to be used and extend the life of the repaired metal melting furnace as much as possible. The purpose is to do.

[0008]

In order to achieve the above object, according to the present invention, metal melting for repairing a erosion region of a lining refractory eroded by intermittent operation of a metal smelting furnace with a refractory repair material. In a repair device for a furnace, a refractory residual thickness detecting means which is buried in a region of the metal melting furnace which is likely to be melted in advance and which detects the residual thickness of the lining refractory remaining after tapping at predetermined intervals, and the refractory. The residual thickness detected by the residual thickness detecting means is compared with a predetermined residual thickness value which is predetermined corresponding to the number of taps after the operation of the metal melting furnace, and at least when the residual thickness is smaller than the predetermined residual thickness value, There is provided a repairing device for a metal melting furnace, comprising: repair control means for repairing an excessive erosion region with the refractory repair material.

[0009]

[Function] The residual thickness of the refractory in the excessive erosion region is detected, and the refractory thickness is compared with the predetermined residual thickness value that has been set in advance corresponding to the number of taps after the operation of the metal smelting furnace. Since the repair of the object is controlled and this is executed periodically every time the residual thickness is detected, the actual residual thickness change can be approximated to a predetermined residual thickness change model. It is possible to use an appropriate amount of repair material at an appropriate time according to the above, and it is possible to approach the ideal furnace life.

[0010]

An embodiment of the present invention will be described with reference to the drawings. First, FIGS. 1 (a) and 1 (b) respectively show a plan view and a side view of a so-called sensor brick 1 used as a refractory residual thickness detecting means of the present invention, which has already been applied by the present applicant. (Practical application 3-27600
issue).

This sensor brick 1 is, as shown in the drawing,
A large number of electrodes are arranged in parallel inside a brick 2 made of a refractory, and wiring is provided so that a plurality of (six in the figure) contact electrodes 4a to 4f branch to a center electrode 3 in the center. The contact points a to f with the respective center electrodes 3 are positioned at a distance in the longitudinal direction of the sensor brick body.

The function of this sensor brick 1 is
In the figure, when the melting loss progresses in the direction of the arrow, the contacts a to the center electrode 3 and the contact electrodes 4a to 4f
Since f is sequentially melted, brick melting loss is detected by generating a potential difference between the electrodes, and the melting width can be generally known by detecting which contact is currently effective. You can do it.

FIG. 2 schematically shows the construction of a metal melting furnace (electric furnace) 5 to which the present invention is applied and a repair control device 6 according to this embodiment. According to this embodiment, The sensor brick 1 described above is embedded in a lined brick portion near the electrode 5a (or electrodes 5b, 5c) provided in the metal melting furnace 5, and its tip 1a is directed toward the center of the furnace and is radially outward from this. It is positioned so as to extend.

Further, the electrodes 3, 4a to 4f from the sensor brick 1 thus embedded are connected via a connector 7 to an electric circuit 8 for converting contact melting damage into an electric signal, and the circuit 8 is formed. The signal representing the brick residual thickness information from the above is input to the control circuit (ECU) 9. The repair control device 6 is further inserted into the furnace of the metal melting furnace 5 after tapping, and the sensor brick 1
A repair device 10 for spraying a refractory repair material (for example, a powder refractory made into a fluid by adding water) to the excessive erosion region near the electrode including the installed portion is provided with the lance (spraying). Nozzle 11) is rotatable in correspondence with the positions of the respective excess erosion regions separated in the furnace circumferential direction, and its operation is controlled by the drive signal output from the control circuit 9. The repair device 10 has a function of measuring the amount of refractory repair material used for repair, and the information is input to the control circuit 9.

Further, the repair control device 6 is further provided with a lance rotational position sensor 12 for detecting the current lance position in order to control the rotation of the above-mentioned lance 11, and the signal thereof is also inputted to the control circuit 9. It In the repair control device 6 configured as described above, the control circuit 9 controls the sensor brick 1 for each dissolution (for each charge) or for every several charges, for example.
Information, that is, the brick residual thickness value T in the excessive erosion region, is taken in, the repair device 10 is driven in accordance with the residual thickness, and the refractory repair material is used for repair.

FIG. 3 is a graph showing the target amount of erosion loss as a reference for determining whether the detected brick residual thickness value T requires repair or not. It is approximately equivalent to the change over time in the remaining brick thickness other than the area, and is experimentally obtained in advance corresponding to the metal melting furnace 5 to be repaired, and can be stored as a map in the memory of the control circuit 9. Is.

In this figure, the vertical axis represents the brick residual thickness value T.
(Mm), the horizontal axis indicates the number of charges C after lining as a representative characteristic value of furnace life, the one-dot chain line indicates the residual thickness minimum value line that requires total relining, and Cf is the set furnace life target. , The dotted line shows the target erosion line (outside the excess erosion region), and the solid line shows the residual thickness change model detected by the sensor brick 1.

An example of the operation of the control circuit 9 which controls the operation of the repair control device 6 according to this embodiment will be described below with reference to FIGS. 3 and 4. FIG. 4 is a control flow chart executed by the control circuit 9, and is a program executed by operating the repair control device 6 by an operator, for example, every time charging (dissolution) is completed. In this flowchart, the elapsed time from the time when the entire furnace is lined (start of operation) is viewed by the number of charges, corresponding to the life of the furnace shown in the map of FIG.

Therefore, in step S1, in order to define where the current state of the metal melting furnace 5 is located on the horizontal axis of FIG. 3, an increment process is performed on the number C of charges so far. The charge number C is naturally initialized to 0 at the start of operation. Then step S
In 2, it is determined whether or not the current charge number C has reached the set life charge number Cf in FIG. 3, and if Yes, the process proceeds to step S6, for example, the current state of the furnace requires a total refill. A message to that effect is displayed to notify the operator, the charge number C is cleared in step S7, and this routine ends.

On the other hand, if the set life has not been reached (No in step S2), the routine proceeds to step S3, and the brick residual thickness information from the sensor brick 1 signaled via the electric circuit 8 is obtained. Read and detect the current remaining thickness T. Then, in a succeeding step S4, it is determined whether or not the current remaining thickness T detected in this way is smaller than the target melting loss value A (c) corresponding to the current charge number C defined in FIG.

In step S4, Yes, that is, the current remaining thickness T
Is determined to be smaller than the target melt loss value A (c) [for example, the position of (a) in FIG. 3], in this case, the excess melt damage region in which the sensor brick 1 is arranged more than other furnace regions. Since it is estimated that the amount of melt-ablation is large, the routine proceeds to step S5, starts the operation of the repair device 10 described above, and executes the process of repairing the excessive melt-damage region. This step S
The specific repair processing contents in 5 will be described later.

On the other hand, if it is judged No in step S4 and the current remaining thickness T is larger than the target value A (c) [the position of (b) in FIG. 3], excessive melting loss due to the previous repair is performed. It is also judged that the refractory repair material formed in the area still remains, and the residual thickness of the refractory (brick + repair material) in this area is larger than the remaining brick thickness in other areas. Therefore, the repair process is not performed, and step S5 is skipped to end this routine.

It should be noted that, in FIG. 3, the brick residual thickness line to be detected has a step-like shape because the contact points a to f of the sensor brick 1 are not continuous as shown in FIG. This is because the output continues to show the value corresponding to the outer contact when the actual tip position of the sensor brick after melting is between the contacts.

By the way, when the residual thickness value T detected with respect to the target brick residual thickness A (c) as described above is recognized to be small, when the repair is performed, the detected residual thickness value T and the actual residual value T Since the thickness value may differ depending on the sensor accuracy, it is necessary to repair it so that there is no difference in the refractory thickness between the actual excess erosion region and other regions. preferable.

However, repairing while actually monitoring the thickness of the repaired portion requires provision of a thickness detection device (for example, a laser detection device) for that purpose, which increases equipment costs and requires a lot of labor. May be required. Therefore, in this embodiment, in step S5 of the above-mentioned flow chart, repair is performed according to the following criteria so that the cumulative amount of repair material used until the next total refill (1 cycle of total brick refill) is almost constant. Control.

FIG. 5 shows whether the cumulative value of the repair material used so far is larger or smaller than the reference usage amount corresponding to the life of the furnace, and the degree thereof, which is reflected in this repair. The graph is used for this purpose and is stored in the memory of the control circuit 9 as a map.
The reference usage amount line shown by the dotted line in the figure can be obtained from the cumulative value Qmin of repair material when the metal melting furnace is continuously operated for the longest time without excess or deficiency of repair material, or once melting It is also possible to experimentally determine the refractory erosion loss difference Δm between the excess erosion region and the other region that occurs in (charge), and by multiplying this by the total number of charges per brick replacement cycle.

According to the device of this embodiment, however, the repair device 10 has a function of weighing the repair material used for each repair as described above, and therefore the control circuit 9 takes this information as information, each time The cumulative amount of use Q up to the present is calculated. Then, in step S5, this is compared with the reference usage amount Q (c) corresponding to the current charge number C, and Q
In the case of (c)> Q, the repair device 10 corresponds to the difference ΔQ.
To repair the material by spraying a repair material on the contrary, Q (c) ≦ Q
In the case of, the process of repairing by a predetermined amount q is executed so that the current difference ΔQ does not become too large, and finally the cumulative usage amount Q at the end of one cycle of operation is the cumulative amount defined in the map. Repair control is performed so as to be approximately equal to Qmin, and as a result, it becomes possible to maximize the life of the furnace with the least amount of repair material used. In this repair process, the other electrodes 5b and 5c are controlled by the repair device drive control of the control circuit 9 which receives the signal from the rotational position sensor 12.
The same is performed in the excessive melting damage region corresponding to.

In the above, the repair device of the present invention has been described with reference to the embodiment in which the sensor brick is used as the refractory residual thickness detecting means. According to this embodiment, this strand (electrode) is directly embedded in the brick. By using a sensor brick with a structure, it is possible to secure a sufficient insulation distance between the wires, and therefore the wires that can be found in other sensors (for example, sheath thermocouple type melt detection sensor). Problems such as re-conduction (erroneous detection) due to molten metal splash adhesion due to the short distance are eliminated.

To solve the problem of residual thickness erroneous detection due to re-conduction of the part that has once been disconnected, in addition to the use of the above-mentioned sensor brick, re-conduction of the part that has been once disconnected in the control circuit By providing a circuit (relay circuit) for canceling the above, the reliability of the residual thickness measurement may be improved. As the output of the control circuit, in addition to the drive control of the repair device described above, graphs such as those shown in FIG. 3 and FIG. May be notified to call attention.

Furthermore, the residual thickness measurement interval of the device of the present invention is not limited to each charge described in the embodiment, and it is of course possible to measure the residual thickness every plural charges, and the residual thickness detecting means. Alternatively, the arrangement may be provided corresponding to each excessive melting region, and the repair device may be drive-controlled corresponding to each detected value.

[0031]

As described above, according to the present invention,
The residual refractory thickness in the excess erosion region detected at predetermined intervals is compared with a predetermined residual thickness value that corresponds to the number of taps after the start of the metal melting furnace operation, and repairs are performed sequentially according to the difference. Since the operation is repeated while controlling, the furnace operation can be brought close to a predetermined efficient operating state, and the basic unit of repair material is improved by about 20% compared with the conventional one,
Also, the furnace life is 500 from the conventional 200-600 charge.
-Extended to 700 charges.

[Brief description of drawings]

1A and 1B show the appearance of a sensor brick of a refractory residual thickness detecting means of a device of the present invention, wherein FIG. 1A is a view from above and FIG. 1B is a view from a side thereof.

FIG. 2 is a schematic configuration diagram showing a repair device and a metal melting furnace according to the present invention.

FIG. 3 is a diagram showing a relationship between a brick residual thickness and a furnace life preset as a melting loss target in repair control of the apparatus according to the present embodiment.

FIG. 4 is a control flowchart illustrating the operation of the control circuit of the device according to the present embodiment.

FIG. 5 is a diagram showing the relationship between the amount of repair material used and the life of the furnace, which is preset as a target for using the repair material in the furnace repair of the apparatus according to the present embodiment.

[Explanation of symbols]

 1 ... Sensor brick 5 ... Metal melting furnace 6 ... Repair device 9 ... Control circuit 10 ... Repair device

Front Page Continuation (72) Inventor Keitoshi Nagoshi 3434 Shimada, Hikari City, Yamaguchi Prefecture Nippon Steel Corporation Hikari Steel Works Ltd.

Claims (1)

[Claims] 1. A repair device for a metal melting furnace for repairing a melted region of a refractory lining, which is melted due to intermittent operation of the metal melting furnace, with a repair device for the metal melting furnace, wherein the metal melting furnace is previously melted. A refractory residual thickness detecting means for detecting the residual thickness of the lining refractory remaining after tapping at a predetermined interval and a metal melting furnace for measuring the residual thickness detected by the refractory residual thickness detecting means. A repair to compare the excess melt damage area with the refractory repair material when at least the above residual thickness is smaller than the predetermined residual thickness value by comparing with a predetermined residual thickness value that corresponds to the number of taps after the start of operation. A repair device for a metal melting furnace, comprising: a control means.