JP6165656B2 - Life prediction method for refractories in the furnace - Google Patents

Description

  The present invention relates to a method for measuring the shape of a refractory provided inside various furnace bodies used in the steelmaking field and predicting the life of the refractory in the furnace from the measurement result.

  As is well known, various furnace bodies such as a blast furnace, a converter, and a heating furnace are used in the steelmaking field. Although the refractory is lined inside these furnace bodies, the refractory is gradually worn out by the temperature and atmosphere during the treatment process in the furnace body. If this amount of wear is not properly managed, it will lead to troubles such as opening a hole in the furnace wall, or wasteful replacement of refractories.

Therefore, in order to appropriately manage the amount of wear of the refractory, it is conceivable to directly measure the shape of the refractory provided inside the furnace body, and there is a technique disclosed in Patent Document 1 and the like.
Patent Document 1 discloses a method for detecting the remaining thickness of a refractory in an electric furnace, in which a temperature sensor is provided in the refractory layer of the main body of the electric furnace, and the remaining thickness of the refractory layer is detected corresponding to the detected temperature. .

JP-A-8-94264

Even when trying to detect the remaining thickness of the refractory using the technique of Patent Document 1 described above, it is difficult to measure the remaining thickness of the refractory other than the place where the temperature sensor is installed, and it is difficult to evaluate local wear. There is. In particular, when the size of the furnace is large or the shape of the furnace is complicated such that the inside is curved, it may be difficult to evaluate the wear of the refractory.
In addition, it is conceivable to install a large number of temperature sensors in the furnace to accommodate large sizes and complex shapes, but increasing the number of temperature sensors installed not only increases costs but also increases refractories. There is no denying that it may lead to deterioration of maintainability and workability. In addition, in the measurement of the remaining thickness of the refractory by the temperature sensor, there is a possibility that the detection accuracy may be deteriorated when there is infiltration of deposits or slag on the surface of the refractory in the furnace.

That is, it must be said that it is currently difficult to measure the shape of the refractory using the technique of Patent Document 1 and to predict the life of the refractory in the furnace from the measurement result.
Moreover, it is difficult to predict the life of the refractory in the furnace even if only the result of the remaining thickness measurement of the refractory at the present time is used. In other words, refractory erosion is closely related to parameters such as operating conditions of the furnace, and in order not to clarify the relationship between these operating conditions and the measurement results of the remaining thickness of the refractory, It is difficult to accurately predict the life of an object. In addition, the position and location of the refractory in the furnace is deeply related to the refractory melted state, and the relationship between the position where the refractory is applied and the measurement result of the remaining thickness of the refractory shall not be clarified. Therefore, it is difficult to accurately predict the life of the refractory in the furnace.

  The present invention has been made in view of the above problems, and can reliably measure the shape of a refractory in a furnace even in a large-sized furnace or a furnace body having a curved shape. It aims at providing the measuring method of a refractory wear state in a furnace. Another object of the present invention is to provide a method for predicting the life of a refractory based on the operating conditions of the furnace body and the results of wear measurement of the refractory.

In order to achieve the above object, the present invention takes the following technical means.
That is, the life prediction method for a refractory in a furnace according to the present invention detects the wear state of the refractory by measuring the surface shape of the refractory lined inside the furnace body, and detects the detected refractory. A method for predicting the life of a refractory in a furnace for predicting the life of the refractory based on the state of wear of the object, wherein the three-dimensional shape of the furnace inner wall obtained by measuring immediately after repairing the furnace body is used as reference data Obtaining and obtaining the three-dimensional shape of the furnace inner wall obtained by measuring after operating the furnace body as operation data, obtaining the wear rate of the refractory from the difference between the reference data and the operation data, The life of the refractory is predicted based on the wear rate of the object and the operating conditions of the furnace body.

Preferably, the relationship between the past operating conditions of the furnace body and the wear rate is constructed as a wear rate database, and the life of the refractory is predicted based on the wear rate database.
Preferably, at least one of the temperature history in the furnace, the atmosphere in the furnace, the flow rate of the atmosphere in the furnace, and the amount of the product in the furnace is preferably adopted as the operation condition.

Preferably, the furnace inner wall of the furnace body is partitioned into a plurality of regions, the reference data and the operation data are acquired for each region, and the reference data and the operation data are obtained in each region. The wear rate of the refractory is obtained from the difference, and the life of the refractory in the region is predicted based on the wear rate of the refractory in each region and the operating conditions of the furnace body.
Preferably, the measurement means for measuring the two-dimensional shape in the furnace by irradiating the refractory with measurement light is measured a plurality of times while being moved in the furnace by the moving means. The reference data and the operation data may be obtained based on the obtained three-dimensional shape.

Preferably, a TOF type distance sensor that measures the distance to the refractory by irradiating the refractory with measurement light is preferably used as the measurement means.
Preferably, a light-cutting distance sensor that measures the two-dimensional shape of the refractory based on a light cutting method after irradiating the refractory with line-shaped measurement light as the measuring means is preferably employed. It is good to be.

  According to the method for predicting the lifetime of a refractory in a furnace according to the present invention, it is possible to accurately predict the lifetime of a refractory attached to a furnace such as a blast furnace, a converter, or a heating furnace.

The top view and sectional drawing (AA cross section) of a U-shaped furnace are shown. It is the figure which showed the condition (TOF type distance sensor) of the measurement light irradiated from the shape measuring apparatus used for the lifetime prediction method of the refractory in a furnace of this invention. It is the figure which showed the condition of the measurement light irradiated from the moving shape measuring apparatus. It is the figure which showed the structure (light cutting type distance sensor) of the shape measuring device. It is the figure which showed the shape (reference | standard data) of the furnace body after furnace repair, and the shape (after-operation data) of the furnace body after operating for a predetermined time. It is the figure which showed the relationship between the operating condition of a furnace, and the amount of wear of a refractory.

Hereinafter, an embodiment of a method for predicting the lifetime of a furnace refractory according to the present invention will be described with reference to the drawings.
[First embodiment]
In the steelmaking field, various furnace bodies such as a blast furnace, a converter, a heating furnace, and the like are used. Refractories are lined inside these furnace bodies. In this embodiment, a U-shaped furnace 1 having an internally curved shape will be described as an example of the furnace body.

As shown in FIG. 1, the U-shaped furnace 1 has a curved portion 2 having a substantially semicircular shape, and the curved portion 2 has a large outer diameter of several tens of meters. The cross section of the bending portion 2 has a rectangular shape with a width of several meters and a height of several meters.
A refractory 9 is stretched on the side wall 4 and the ceiling 5 (ceiling) inside the U-shaped furnace 1. The bottom (hearth) 6 of the U-shaped furnace 1 is movable, and the movable hearth 6 moves along the curvature of the curved portion 2 by moving on the laid rail 7. . On the hearth 6, for example, a processing target such as a slab is placed, and as the hearth 6 moves through the curved portion 2 of the U-shaped furnace, the temperature of the processing target slab increases. It will be. In this embodiment, the U-shaped furnace 1 has been described as an example. However, as a matter of course, the present invention can be applied to other furnace bodies. For example, the present invention can also be applied to a rotary furnace in which a steelmaking raw material such as pellets is charged into the hearth 6 and the reaction proceeds while rotating the hearth 6 along the rail 7.

The above-mentioned refractory inside the furnace body is gradually worn away depending on the temperature and atmosphere during the process in the furnace. If the wear of the refractory progresses, there is a possibility that a hole will open in the furnace wall, so it is necessary to manage the wear of the refractory. However, when managing the wear of the refractory, if the refractory is replaced while the wear of the refractory is not progressing, the refractory that can be used is discarded, and the refractory may be wasted.

  Therefore, in the method for predicting the life of a refractory in a furnace according to the present invention, the wear state of the refractory is detected by measuring the surface shape of the refractory lined inside the furnace body. When predicting the life of a refractory based on the wear state, the three-dimensional shape of the inner wall of the furnace obtained by measuring immediately after repairing the furnace body is obtained as reference data, and measured after operating the furnace body. The obtained three-dimensional shape of the inner wall of the furnace is obtained as operation data, the wear rate of the refractory is obtained from the difference between the reference data and the operation data, and the fire resistance is determined based on the wear rate of the refractory and the operating conditions of the furnace body Predict the life of things.

For obtaining the three-dimensional shape of the inner wall of the furnace as described above, as shown in FIG. 2, the shape of the furnace (the refractory is worn out) by the distance sensor 10 which is a measuring means installed inside the furnace body (inside the furnace). ) Is used. By using such a shape measuring device, it becomes possible to appropriately recognize and manage the amount of wear of the refractory.
Specifically, the shape measuring apparatus of the present embodiment irradiates a refractory with laser light (measurement light), receives light reflected by the refractory (reflected light) with a light receiving sensor, A TOF type distance sensor 10 for detecting a time difference and obtaining a distance from the time difference and the light source to the refractory is provided.

With reference to FIG. 2, the shape measurement in the furnace using the distance sensor 10 (TOF type distance sensor), particularly an example in which the distance sensor 10 is installed in the curved portion 2 of the U-shaped furnace 1 will be described in detail.
As shown in FIG. 2, a distance sensor 10 is installed at the center of the hearth 6 in the width direction. For example, when installing the distance sensor 10 on the curved portion 2 of the hearth 6, the distance sensor 10 is installed in the central portion (same as the central portion in the width direction) of the curved portion 2 that is arcuate. To do.

  The distance sensor 10 is installed so that the scanning surface of the laser beam L faces the direction along the radial direction of the bending portion 2. After the distance sensor 10 is installed, for example, the laser beam L is irradiated toward the refractory at the lower end of the outer side wall 4a (referred to as the outer wall 4a) to the laser reflection point on the refractory 9 from the distance sensor 10. First measure the distance. Next, scanning is performed while gradually irradiating the laser beam L toward the ceiling portion 5, and the distance to the laser beam reflection point is measured at every fixed movement angle during the scanning. When the refractory on the lower side of the inner side wall 4b (referred to as the inner side wall 4b) is irradiated, the irradiation and scanning of the laser light L are finished.

  That is, by performing scanning while irradiating the laser beam L over the outer wall portion 4a, the ceiling portion 5 and the inner wall portion 4b, the furnace wall (refractory in the furnace) from the distance sensor 10 in one scan. Measure the distance to. The time required for one scan is 0.1 second. A measurement value obtained by the distance sensor 10 is stored in a storage unit of a computer (not shown) and converted into coordinates indicating a two-dimensional shape.

Next, when the scanning in the furnace at the predetermined position is completed, the distance sensor 10 is moved by the moving means. As shown in FIG. 3, the position of the distance sensor 10 can be changed by moving (rotating) the hearth 6 along the rail 7.
After the movement of the hearth 6, as described with reference to FIG. 2, the inside of the furnace is scanned by the same method. Then, scanning in the furnace and movement of the hearth 6 are repeated to obtain a plurality of continuous two-dimensional shapes in a predetermined section in the furnace. This two-dimensional shape is the shape of the outer wall 4a, the ceiling 5 and the inner wall 4b excluding the hearth 6. And the three-dimensional shape in a furnace can be calculated | required by arranging the two-dimensional shape calculated | required in this way continuously along a moving direction (along the rail 7). In addition, it is desirable that the movement pitch of the hearth 6 (the movement pitch of the distance sensor 10) be smaller than the width of the joint which is a joint between the refractories.

  In the above-described embodiment, an example in which a TOF type distance sensor is used as the distance sensor 10 has been described. However, as illustrated in FIG. 4, as the distance sensor 10, the linear measurement light irradiated to the refractory is used as the camera 11. A light-cutting distance sensor based on a light-cutting method that measures a two-dimensional shape by taking an image may be employed. It should be noted that the method of moving along the inside of the furnace is the same in the light-cutting distance sensor.

As described above, a plurality of two-dimensional shapes can be obtained by moving the distance sensor 10 in the furnace by the moving means (the hearth 6 moving on the rail 7). And by connecting these two-dimensional shapes, a three-dimensional shape in the furnace can be obtained.
Next, the grasp of the wear state of the refractory based on the measurement result will be described.
In the case of this embodiment, as a method for measuring the wear state, the inner shape (the inner shape immediately after the repair) when the refractory is not worn is estimated, and the inner shape immediately after the repair and the inner side after the operation of the furnace body A method is adopted in which the wear state of the refractory is determined by comparing the shape.

  That is, immediately after repairing the refractory in the furnace, the shape (three-dimensional shape) in the furnace is measured and the three-dimensional shape is used as reference data. Next, the in-furnace shape (three-dimensional shape) after operating the furnace for a predetermined period is measured, and the three-dimensional shape is used as post-operation data. Then, the wear state (wear amount) of the refractory is predicted from the difference between the reference data and the post-operation data. The following prediction and calculation processes are realized by the function of the computer. More specifically, it is realized by a CPU in the computer executing a computer program that executes the following processing.

Specifically, after repairing the refractory in the furnace, the distance sensor 10 is installed in the furnace immediately after the repair. As shown in FIG. 2, a plurality of two-dimensional shapes in the furnace are acquired by the distance sensor 10, and the three-dimensional shape obtained from the two-dimensional shape is used as reference data.
Next, as shown in FIG. 5 (the left figure of FIG. 5), the furnace inner wall of the furnace body is partitioned in advance into a plurality of regions (in the example of FIG. 5, “1” to “9”), The reference data measured for each area is associated. Similarly, post-operation data measured for each area is associated. FIG. 5 shows an example in which the inner wall of the furnace is developed in a planar shape, and the amount of wear is two-dimensionally mapped for each region. In FIG. 5, it has shown that the amount of wear is so large that the area | region where the gray scale became thin. For example, in FIG. 5, the region “8” has the largest amount of wear.

Thereafter, based on the obtained measurement results, the difference between the reference data and the operation data is obtained in each region, and the wear rate of the refractory is obtained based on the operation period (operation time). As the wear rate, for example, a wear rate per month (mm / month) can be considered.
Based on the wear rate for each region thus obtained, the current wear amount and the predicted wear amount until the next repair (= wear rate × number of months of operation) are calculated. If the calculated predicted amount of wear at the next repair is below the refractory management value, it is determined that the life of the refractory will be reached at the time of the next repair, and the next repair is determined to be necessary for that area. . For safety reasons, the refractory may be repaired without waiting for complete wear and tear to be confirmed at the time of measurement (current time).

  In the furnace, there is a difference in temperature distribution and the like, and not all refractories are worn out uniformly. In other words, there is a region that is easily worn out. Therefore, as in the present embodiment, the furnace inner wall is divided into a plurality of regions, the wear rate for each region is obtained, and the refractory in each region is obtained using the obtained wear rate in each region. By predicting the lifetime of the furnace, it becomes possible to reliably manage and repair the furnace.

  As an example of lifetime estimation, for example, attention is focused on a region “5” in FIG. It is assumed that the thickness of the refractory is measured to be 500 mm from the reference data immediately after the refractory is replaced. The amount of wear at this time is 0 mm. After that, after operating the furnace for 3 months, the thickness of the refractory in the region “5” was measured to obtain post-operation data, and it was revealed that the refractory thickness was reduced to 450 mm. At this time, the amount of wear in the region 5 is 50 mm and the operation period is 3 months, so the wear rate is calculated as 50/3 = 16.7 mm / month.

  If the operating conditions do not change greatly and wear continues at the same pace in the future, the refractory life will be estimated as refractory remaining thickness / wear rate = 450 / 16.7 = 27 months. In other words, the remaining thickness of the refractory is expected to be 0 mm after 27 months. However, because there are actually problems with safety and equipment maintenance, the thickness of the refractory will not be used up to 0 mm. In this example, the remaining thickness of about 50 to 100 mm is left and repairs are made. Become. That is, it is predicted that the refractory life (refractory remaining thickness / wear rate) = (450-100) /16.7=21 months, and it is better to perform refractory replacement after 21 months.

In addition, it is known that the state of wear of the refractory in the furnace body varies greatly depending on the operating conditions of the furnace. For example, when the production amount of the product by the furnace body is increased, it is considered that the amount of heat in the furnace increases with the increase in production and the wear amount of the refractory increases. That is, the wear rate of the refractory (for example, the wear rate per month) is not always constant, and is considered to fluctuate in conjunction with operating conditions. Therefore, in the present embodiment, the relationship between the past operating conditions of the furnace and the wear rate is constructed as a wear rate database, and the lifetime of the refractory is predicted based on the constructed wear rate database.

  FIG. 6 is an example of a wear rate database. The horizontal axis of this database (graph) is the furnace temperature (for example, average temperature), and the vertical axis is the refractory wear rate (for example, mm / month). When it is desired to estimate the life of the refractory in the furnace, the furnace temperature condition is applied to a database as shown in FIG. 6, and then the wear rate is obtained. Based on the obtained wear rate, the life of the refractory in the furnace is calculated. It is good to estimate.

As the wear rate database, at least one of the temperature history in the furnace, the atmosphere in the furnace, the flow rate of the atmosphere in the furnace, and the amount of products in the furnace is adopted, and the relationship between the adopted parameters and the wear rate. Is preferably constructed as a wear rate database.
As described above, according to the present invention, the degree of wear of a refractory can be evaluated easily and accurately by comparing with the in-furnace shape immediately after repair (no refractory wear), and the obtained wear rate can be used. Even in a large-sized furnace or a furnace body having a curved shape, the life of the refractory in the furnace can be accurately predicted.

  By the way, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. In particular, in the embodiment disclosed this time, matters that are not explicitly disclosed, for example, operating conditions and operating conditions, various parameters, dimensions, weights, volumes, and the like of a component deviate from a range that a person skilled in the art normally performs. Instead, values that can be easily assumed by those skilled in the art are employed.

1 Furnace (U-shaped furnace)
2 Curved part 4 Side wall part 4a Outer side wall part 4b Inner side wall part 5 Ceiling part 6 Hearth 7 Rail 8 Corner part 10 Distance sensor

Claims (7)

A furnace that detects the wear state of the refractory by measuring the surface shape of the refractory lined inside the furnace body, and predicts the life of the refractory based on the detected wear state of the refractory A method for predicting the life of an internal refractory,
Obtaining the three-dimensional shape of the furnace inner wall obtained by measuring immediately after repairing the furnace body as reference data,
Obtaining the three-dimensional shape of the inner wall of the furnace obtained by measuring after operating the furnace body as operation data;
From the difference between the reference data and the operation data, the wear rate of the refractory is obtained,
A method for predicting the life of a refractory in a furnace, wherein the life of the refractory is predicted based on the wear rate of the refractory and the operating conditions of the furnace body. The relationship between the past operating conditions of the furnace body and the wear rate is constructed as a wear rate database,
The lifetime prediction method of the refractory in a furnace according to claim 1, wherein the lifetime of the refractory is predicted based on the wear rate database.   3. The method according to claim 1, wherein at least one of a temperature history in the furnace, an atmosphere in the furnace, a flow rate of the atmosphere in the furnace, and an amount of the product in the furnace is adopted as the operation condition. Life prediction method for refractories in the furnace. Dividing the furnace inner wall of the furnace body into a plurality of regions;
For all areas, obtain the reference data and operation data,
In each area, from the difference between the reference data and the operation data, the wear rate of the refractory is obtained,
The lifetime of the refractory in the region is predicted based on the wear rate of the refractory in each region and the operating conditions of the furnace body. Refractory life prediction method.   The measuring means for measuring the two-dimensional shape in the furnace by irradiating the refractory with the measuring light is measured a plurality of times while being moved in the furnace by the moving means, thereby measuring the three-dimensional shape in the furnace. The method for predicting the lifetime of a refractory in a furnace according to any one of claims 1 to 4, wherein the reference data and the operation data are obtained based on the obtained three-dimensional shape.   The in-furnace refractory according to claim 5, wherein a TOF type distance sensor that measures a distance to the refractory by irradiating measurement light toward the refractory as the measurement means is adopted. Life expectancy prediction method.   As the measuring means, a light-cutting distance sensor that measures a two-dimensional shape of the refractory based on a light cutting method after irradiating the refractory with linear measurement light is used. The lifetime prediction method of the refractory in a furnace of Claim 6.