JP2021089265A - Furnace wall shape/wear measuring device and furnace wall shape/wear measuring method - Google Patents

Abstract

To provide a furnace wall shape/wear measuring device for providing sufficient information in a short time.SOLUTION: A furnace wall shape/wear measuring device comprises a light source that generates a mark on an intersection line between a furnace wall surface and a first plane including a light emission point O, a first camera that acquires an image of the mark, and a processor. The light source and the first camera are configured to be rotatable around a rotation axis. Using the visual field central axis of the first camera as a w-axis, the principal point C of the first camera on the w axis as the origin, and two straight lines orthogonal to each other in a plane that includes the origin and is perpendicular to the w-axis as a u-axis and a v-axis, the processor obtains, from u, v coordinates of a measurement point on the mark in the image acquired by the first camera, the azimuth angle and the elevation angle of the measurement point. From the azimuth angle, the elevation angle, and the relative positional relationship between the visual field central axis and the first plane, the furnace wall shape/wear can be determined.SELECTED DRAWING: Figure 6

Description

The present invention relates to a furnace wall shape / wear measuring device and a furnace wall shape / wear measuring method. The present invention is particularly suitable for an electric furnace for steelmaking.

The electric furnace for steelmaking repeats the process of melting iron scrap at high temperature and taking out molten steel. The furnace wall exposed to high temperature is formed of refractory material. By repeating the above process, the surface of the refractory wall is gradually worn. If this wear is left unattended, the possibility of a major accident such as damage to the furnace body increases. Therefore, a method for determining the state of wear of the refractory has been developed.

In the conventional method, there is a method of indirectly estimating the state of wear of the furnace wall based on the temperature measurement inside the refractory (for example, Patent Documents 1-3). However, these methods could not directly measure the state of wear of the furnace wall. Further, a method of measuring the shape of a furnace wall by combining a laser beam and a linear array sensor has been developed (for example, Patent Document 4). However, in this method, the measurement procedure is complicated and the measurement time is long, so that it is not possible to measure the shape of the furnace wall, for example, between the output of steel from an electric furnace and the input of raw materials. In this way, a furnace wall shape / wear measuring device and a furnace wall shape / wear measuring method that provide sufficient information on the wear state of the furnace wall in a short time for repair by the furnace wall repair machine have been conventionally developed. I wasn't.

Japanese Unexamined Patent Publication No. 3-223658 Japanese Unexamined Patent Publication No. 8-94264 Japanese Unexamined Patent Publication No. 2017-227350 Japanese Unexamined Patent Publication No. 58-196406

Therefore, there is a need for a furnace wall shape / wear measuring device and a furnace wall shape / wear measuring method that provide sufficient information on the wear state of the furnace wall in a short time for repair by the furnace wall repair machine. The technical subject of the present invention is a furnace wall shape / wear measuring device and a furnace wall shape / wear measuring method that provide sufficient information on the wear state of the furnace wall in a short time for repair by a furnace wall repair machine. To provide.

The shape / wear measuring device for the furnace wall according to the first aspect of the present invention has a central axis, and the cross section perpendicular to the central axis has a circular shape having a center on the central axis. It comprises a light source that is used to generate a light beam mark on the furnace wall, a first camera that acquires an image of the mark, and a processor. The light source and the first camera are installed in the vicinity of the central axis and are configured to be rotatable around a rotation axis in the direction of the central axis, and the light emitting point O of the light source is substantially on the rotation axis. Positioned, the light source is configured to generate the mark on the intersection of the first plane containing the light emitting point O and the surface of the furnace wall, and the light source and the first camera are in relative positions. When rotating around the rotation axis while maintaining the relationship, the first plane is configured to rotate around the rotation axis, and the w axis is on the center axis of the field of view of the first camera, and the w axis is defined as the w axis. With the main point C of the first camera above as the origin, and the two straight lines including the origin and orthogonal to each other in the plane perpendicular to the w-axis as the u-axis and the v-axis, the processor is around the rotation axis. The azimuth angle and elevation / depression angle of the measurement point are obtained from the u and v coordinates of the measurement point on the mark in the image acquired by the first camera that rotates to, and the azimuth angle, the elevation / depression angle, and the center axis of the field of view are obtained. The distance between the main point C and the measurement point and the direction from the main point C to the measurement point are obtained from the relative positional relationship between the main point C and the first plane, and the main point C and the measurement point are obtained. It is configured so that the shape and wear of the furnace wall can be determined from the distance between the points and the direction from the main point C to the measurement point.

The furnace wall shape / wear measuring device of this embodiment provides sufficient information on the wear state of the furnace wall in a short time for repair by the furnace wall repair machine, for example, between the steel removal of the electric furnace and the input of the raw material. Can be provided to.

In the furnace wall shape / wear measuring device of the first embodiment of the first aspect of the present invention, the first plane is configured to be orthogonal to the plane formed by the u-axis and the w-axis. ..

According to this embodiment, the calculation for obtaining the distance between the principal point C and the measurement point becomes simple.

In the furnace wall shape / wear measuring device of the second embodiment of the first aspect of the present invention, the light emitting point O is configured to be located on the u-axis.

According to this embodiment, the calculation for obtaining the distance between the principal point C and the measurement point becomes simple.

In the furnace wall shape / wear measuring device of the third embodiment of the first aspect of the present invention, the distance between the points C and O is d, and the intersection of the w-axis and the first surface is P _0. the acute angle formed between the line connecting the w-axis and the point O and the point P ₀ as gamma, d is from approximately 500 millimeters to 1500 millimeters, a range gamma of 23 degrees 8 degrees.

According to this embodiment, the shape and wear along the inner circumference of the furnace wall can be measured with high accuracy by appropriately setting the above distance and angle.

In the furnace wall shape / wear measuring device of the fourth embodiment of the first aspect of the present invention, the light source is a laser line generator that emits a laser beam into the first plane, and the mark is a laser. It is a line.

According to the present embodiment, by using the laser line as a mark by light rays, it is possible to perform the measurement in a short time while the furnace is in a high temperature state between the processes of the furnace, so that the temperature of the furnace is high between the processes of the furnace. Sufficient information on the state of wear of the furnace wall can be provided for repair by the furnace wall repair machine carried out in the state.

The shape / wear measuring device for the furnace wall according to the fifth embodiment of the first aspect of the present invention is configured so that the direction of the laser beam emitted by the laser line generator can be changed.

According to this embodiment, it is possible to measure the shape and wear along the inner circumference of a wide range of the furnace wall.

The shape / wear measuring device for the furnace wall according to the sixth embodiment of the first aspect of the present invention further includes a second camera for acquiring an image of the furnace wall, a display, and the second. The camera is installed in the vicinity of the central axis so that an image of the furnace wall can be acquired along the inner circumference of the furnace wall, and is configured to be rotatable around the rotation axis so that the processor can acquire the image. , An image in which information indicating the shape and wear of the furnace wall is added to the image of the furnace wall is created and displayed by the display.

According to the present embodiment, since it is possible to provide the operator with an image in which information indicating the shape and wear of the furnace wall is added to the image of the furnace wall, repair by the furnace wall repair machine can be efficiently performed.

In the furnace wall shape / wear measuring device of the seventh embodiment of the first aspect of the present invention, the light source is a projector, and the mark is a mark generated by the projector.

According to this embodiment, the image of the mark and the image of the furnace wall can be acquired by one camera.

In the furnace wall shape / wear measuring device of the eighth embodiment of the first aspect of the present invention, the repair of the furnace wall in which the light source and the first camera are rotatably installed in the vicinity of the central axis. It is attached to the machine.

According to this embodiment, it becomes easy to interlock the shape / wear measuring device of the furnace wall with the repair machine.

The method for measuring the shape and wear of the furnace wall according to the second aspect of the present invention has a furnace wall having a central axis, and the cross section perpendicular to the central axis has a circular shape having a center on the central axis. A method for measuring the shape and wear of a furnace wall used in a furnace, which uses a light source that generates a mark by light rays on the furnace wall, a first camera that acquires an image of the mark, and a processor. The light source and the first camera are installed in the vicinity of the central axis and are configured to be rotatable around a rotation axis in the direction of the central axis, and the light emitting point O of the light source is substantially on the rotation axis. The light source is configured so that the mark is generated on the intersection of the surface including the light emitting point O and the surface of the furnace wall, and the central axis of the field of view of the first camera has the axis of rotation. Installed to pass through, the method acquires an image of the mark along the inner circumference of the furnace wall at a predetermined height as the light source and the first camera rotate around the axis of rotation. This includes a step of determining the shape and wear of the furnace wall by using the image of the mark acquired by the processor along the inner circumference of the furnace wall.

In the method for measuring the shape and wear of the furnace wall in this embodiment, sufficient information on the state of wear of the furnace wall can be obtained in a short time for repair by the repair machine of the furnace wall, for example, between the steel removal of the electric furnace and the input of raw materials. Can be provided to.

The method for measuring the shape and wear of the furnace wall according to the first embodiment of the second aspect of the present invention further uses a second camera for acquiring an image of the furnace wall and a display, and the second method. The camera is installed in the vicinity of the central axis, is configured to be rotatable around the rotation axis, and the second camera acquires an image of the furnace wall along the inner circumference of the furnace wall. The step of creating an image in which the processor adds information indicating the shape and wear of the furnace wall to the image of the furnace wall, and information that the processor shows the shape and wear of the furnace wall in the image of the furnace wall. Further includes a step of displaying the image with the addition of the above on the display.

According to the present embodiment, since it is possible to provide the operator with an image in which information indicating the shape and wear of the furnace wall is added to the image of the furnace wall, the furnace is carried out in a high temperature state between the processes of the furnace. Repairs with a wall repair machine can be carried out efficiently.

The method for measuring the shape and wear of the furnace wall according to the second embodiment of the second aspect of the present invention is the shape of the furnace wall determined when the furnace wall is in the reference state and the shape of the furnace wall newly determined. The amount of wear of the furnace wall is determined from the difference between.

According to this embodiment, the amount of wear of the furnace wall from the reference state can be accurately measured.

It is a figure which shows the cross section of the arc type electric furnace for steelmaking. It is a perspective view which shows the shape of the furnace wall and the arrangement of the wear measuring apparatus by one Embodiment of this invention. It is a top view which shows the shape of the furnace wall, and the arrangement of the wear measuring apparatus. It is a block diagram which shows the shape of the furnace wall, and the structure of the wear measuring apparatus. It is a flow chart which shows the method of determining the shape of the inner circumference of the furnace wall in a reference state. It is a figure for demonstrating the positional relationship of the light emitting point of a laser line generator, the principal point of a first camera, and a furnace wall. Is a diagram for explaining the positional relationship between the point O, the point C, the point P ₀ and the plane including the above points. It is a figure for demonstrating the position adjustment method of a laser line generator. It is a figure for demonstrating how to determine the distance from the principal point C of the 1st camera to the measurement point L on a laser line. It is a figure for demonstrating the method of determining the azimuth angle α of the measurement point L, and the elevation / depression angle β of a measurement point L from the image of a 1st camera. FIG. 5 is a flow chart showing a method of determining the shape of the inner circumference of the furnace wall in the reference state using the image of the laser line described in step S1020 of FIG. It is a figure which shows the relationship between the azimuth angle α of the measurement point L, the elevation / depression angle β, and the distance l from the principal point C of the first camera to the measurement point L. It is a figure which shows the shape of the inner circumference of the furnace wall in a reference state measured by the shape and wear measuring apparatus of a furnace wall. It is a flow chart which shows the method of determining the shape and wear of the inner circumference of a furnace wall after steel removal. It is a figure which shows the shape of the inner circumference of the furnace wall after steel removal measured by the shape and wear measuring apparatus of a furnace wall. It is a figure which shows the image of the inner circumference of a furnace wall and the image of a laser line separately. It is a figure which shows the composite image which superposed the image of the laser line on the image of the inner circumference of a furnace wall.

FIG. 1 is a diagram showing a cross section of an arc-type electric furnace 300 for steelmaking. The furnace wall 310 of the electric furnace 300 has a central axis 320, and has a substantially circular shape having a cross section perpendicular to the central axis 320 centered on the central axis 320. The cross section shown in FIG. 1 includes a central axis 320. Iron scrap as a raw material and limestone as an auxiliary raw material are put into the electric furnace 300 and heated to a high temperature by an arc. Iron scrap melts, and impurities such as copper, tin, nickel, and chromium in the iron scrap are absorbed by limestone and become slag. Since slag containing impurities has a small specific gravity, it floats on the molten steel from which impurities have been removed. The molten steel and slag are taken out from the steel outlet and the slag outlet provided on the furnace wall 310, respectively. In this way, in the electric furnace 300, the processes of inputting raw materials and auxiliary raw materials, melting the raw materials, ejecting steel, and discharging the raw materials are repeated.

The furnace wall 310 exposed to high temperature is formed of refractory bricks and castable refractories. The surface of the furnace wall is gradually worn by repeating the above process. If this wear is left unattended, the possibility of a major accident such as damage to the furnace body increases. Therefore, in the furnace 300, a repair machine 200 for spraying a castable refractory is installed at a place where the furnace wall is heavily worn during the process, that is, between the steel ejection and the raw material feeding. The repair machine 200 is configured to be rotatable around a rotation axis in the direction of the central axis 320, which substantially coincides with the central axis 320 of the arc-type electric furnace 300. A nozzle 210 for blowing a castable refractory onto the furnace wall 310 is provided at the tip of the repair machine 200. Further, the nozzle 210 is configured so that the angle can be changed in order to change the spraying position on the furnace wall of the castable refractory. By changing the rotation position of the repair machine 200 and the angle of the nozzle 210, a castable refractory can be sprayed on an arbitrary position on the furnace wall.

The wear of the furnace wall 310 at the position of the slag on the molten steel is the largest. The horizontal straight line indicating the vertical position of the slag on the molten steel is called a slag line 330. In FIG. 1, the slag line 330 is shown by a broken line. When monitoring the shape and wear of the furnace wall 310, it is necessary to preferentially monitor the height portion of the slag line 330 of the furnace wall 310.

FIG. 2 is a perspective view showing the arrangement of the shape / wear measuring device 100 of the furnace wall according to the embodiment of the present invention. In the present embodiment, a laser line generator commercially available under the name of a line generator is used as a light source of the furnace wall shape / wear measuring device 100. The furnace wall shape / wear measuring device 100 captures an image of the furnace wall, a laser line generator 101 that generates a laser line as a mark by light rays on the furnace wall, a first camera 103 that acquires an image of the laser line, and an image of the furnace wall. Includes a second camera 105 to acquire. The laser line generator 101, the first camera 103, and the second camera 105 may be installed in the vicinity of the central axis 320 and may be installed on a flat plate 150 fixed to the repair machine 200. The repair machine 200 is configured to be rotatable around a rotation axis in the direction of the central axis 320, which substantially coincides with the central axis 320. The laser line generator 101 is installed in the vicinity of the rotation axis so as to emit a laser beam in a plane. The laser line generator 101 may be configured so that the direction of the laser beam emitted into the above plane can be changed. When the repair machine 200 rotates around a rotation axis, the laser line generator 101 also rotates around the rotation axis, forming a laser line along the inner circumference of the furnace wall at the height of the slag line 330, for example. The first camera 103 acquires an image of the laser line along the inner circumference of the furnace wall at the height of the slag line 330 while rotating around the rotation axis together with the laser line generator 101. The second camera 105 acquires an image of the furnace wall along the inner circumference while rotating around the rotation axis together with the laser line generator 101 and the first camera 103. The time required for one rotation around the rotation axis for acquiring the image of the laser line along the inner circumference of the furnace wall and the image of the furnace wall along the inner circumference is about 10 seconds.

The laser line is formed in the cross section including the central axis 320 of the furnace wall 310 as an example in the vicinity of the height of the slag line 330. The length of the laser line is, for example, 500 millimeters on the furnace wall 310. In general, the object of measurement by the furnace wall shape / wear measuring device 100 according to the embodiment of the present invention is not limited to the region of the furnace wall at the height of the slag line, but is the entire area of the furnace wall including the bottom of the furnace. If necessary, the laser line generator 101 can be configured so that the direction of the laser beam emitted into the plane can be changed, or the length of the laser line can be lengthened so as to reach from the slag line to the center of the furnace bottom. By configuring the laser line generator 101, the entire area of the furnace wall including the bottom of the furnace can be measured.

FIG. 3 is a plan view showing the shape of the furnace wall and the arrangement of the wear and tear measuring device 100. Hereinafter, it is assumed that the rotation axis of the repair machine 200 coincides with the central axis 320. When the repair machine 200 rotates around the central axis 320, the flat plate 150 also rotates around the central axis 320. The positional relationship between the laser line generator 101 and the first camera 103 does not change during rotation. The viewing angle of the second camera 105 is 70 degrees as an example.

FIG. 4 is a block diagram showing the shape of the furnace wall and the configuration of the wear and tear measuring device 100. The furnace wall shape / wear measuring device 100 includes a laser line generator 101, a first camera 103, a second camera 105, a processor 110, and a display 120. Further, the processor 110 is configured so that the circumferential position during rotation, that is, the rotation angle around the central axis 320 can be taken in from a detector 130 such as an encoder. The processor 110 associates the rotating circumferential position with the images acquired by the first camera 103 and the second camera 105 at that position. The processor 110 determines the shape and wear of the furnace wall from the image of the laser line acquired by the first camera 103. Further, the processor 110 displays on the display 120 an image obtained by combining the image of the furnace wall acquired by the second camera 105 and the information on the shape and wear of the furnace wall. The above functions of the processor 110 will be described in detail later. The laser wavelength of the laser line generator 101 is, for example, 405 nanometers, and the first camera 103 includes a filter that selectively transmits the above wavelengths.

FIG. 5 is a flow chart showing a method of determining the shape of the inner circumference of the furnace wall 310 in the reference state. The standard condition is a condition in which the refractory is not worn immediately after regular repair. Periodic repair is repair that is carried out by lowering the temperature of the furnace on a regular basis, in addition to the repair that is carried out during the process when the furnace is in a high temperature state.

In step S1010 of FIG. 5, an image of the laser line on the inner circumference of the furnace wall 310 in the reference state is acquired by the first camera 103.

In step S1020 of FIG. 5, the processor 110 uses the image of the laser line to determine the shape of the inner circumference of the furnace wall in the reference state. First, the measurement method according to the embodiment of the present invention used in step S1020 of FIG. 5 will be described.

FIG. 6 is a diagram for explaining the positional relationship between the light emitting point of the laser line generator 101, the principal point of the first camera 103, and the surface of the furnace wall 310. In FIG. 6, the light emitting point of the laser line generator 101 and the principal point of the first camera 103 are represented by points O and C, respectively. The wall surface of the furnace is represented by F. The laser line generator 101 is installed so that the point O is substantially located on the rotation axis. Here, "substantially" means that the distance from the rotation axis of the point O is 10% or less of the radius of the cross section of the substantially circular furnace perpendicular to the rotation axis at the height of the point O. The laser line generator 101 emits a laser beam into a plane π (hereinafter referred to as a surface π) to generate a laser line on the intersection of the surface π and the furnace wall surface. Point L in FIG. 6 represents a measurement point on the laser line formed on the furnace wall 310. When the laser line generator 101 rotates around the rotation axis, the laser line moves along the furnace wall surface F, and the first camera 103 moving together with the laser line generator 101 lasers at each position in the circumferential direction of the furnace wall surface F. Get an image of the line. In FIG. 6, the point P ₀ represents the intersection of the central axis of the field of view passing through the principal point C of the first camera 103 and the surface π. Point during rotation O, the relative positional relationship between the point C and the point P ₀ is unchanged as described below.

FIG. 7 is a diagram _{for explaining the positional relationship between the points O, C, P 0,} and the surface including the above points. An uvw Cartesian coordinate system with the point C as the origin and the central axis of the field of view as the w axis is defined. The u-axis and v-axis are two straight lines orthogonal to each other in a plane orthogonal to the w-axis. In FIG. 7, the u-axis, v-axis and w-axis are represented by eu, ev and ew, respectively. In the present embodiment, the point O is configured to be located on the u-axis. The distance between the points C and O is represented by d. Let the plane including the u-axis and the w-axis be the plane Ω, and let the plane including the v-axis and the w-axis be the plane Σ. The plane Ω and the plane Σ are orthogonal to each other. The plane π including the point O is defined to be orthogonal to the plane Ω. How to position the surface π so that the surface π is orthogonal to the surface Ω will be described later. The intersection of the straight line connecting the points O and L on the surface π and the surface Σ is represented by the point P3. Since two points of the point P ₀ and the point P3 included in the two planes of the plane Σ and surfaces [pi, the straight line connecting the point P ₀ and the point P3 is the intersection line of the two planes. Here, the coordinates of the point L are (u, v, w). Let the foot of the perpendicular line drawn from the point L to the surface Ω be the point Lu. The coordinates of the point Lu can be represented by (u, 0, w). Let the foot of the perpendicular line drawn from the point L to the surface Σ be the point Lv. The coordinates of the point Lv can be represented by (0, v, w). Let the foot of the perpendicular line drawn from the point Lv to the surface Ω be the point Lw. The coordinates of the point Lw can be represented by (0, 0, w). The angle (acute angle) between w axis connecting the straight line and the point C and the point P ₀ connecting the points O and the point P ₀ expressed by gamma. The axis of rotation passing through the point O is represented by m. In FIG. 7, the rotation axis m is indicated by a chain double-dashed line. The distance d and the angle γ are fixed values, and the plane Σ, the plane π, and the points in the plane rotate around the rotation axis m while maintaining the mutual positional relationship.

In FIG. 7, an xyz Cartesian coordinate system with the point C as the origin is defined. The x-axis coincides with the u-axis. The y-axis is defined parallel to the rotation axis. The y-axis and z-axis correspond to the v-axis and w-axis rotated by an angle Φ around the u-axis, respectively.

Here, how to determine the position of the surface π so that the surface π is orthogonal to the surface Ω will be described. The first camera 103 is fixed to the flat plate 150 so that the vertical axis of the image of the first camera 103 is perpendicular to the flat plate 150 of FIG. The laser line generator 101 is fixed to the flat plate 150 so that the laser irradiation surface π of the laser line generator 101 is perpendicular to the flat plate 150. The flat plate 150 is fixed to the repair machine 200 in a state where the flat plate 150 is inclined by an angle Φ with respect to the horizontal plane. The surface of the flat plate 150 coincides with the surface Ω.

FIG. 8 is a diagram for explaining a method of adjusting the position of the laser line generator 101. FIG. 8 shows the surface Ω formed by the u-axis and the w-axis. In FIG. 8, R indicates a reflector. The reflector R is inclined at an angle Φ with respect to the vertical direction at a position intersecting the laser irradiation surface π. That is, the reflector R is orthogonal to the surface Ω. The first camera 103 observes the laser line formed on the reflector R, and adjusts the position of the laser line generator 101 and the direction of the laser irradiation surface π so that the laser line is in the vertical axis direction of the image. To do. When the distances from the point O to the reflector R are d1 and d2, the angles (acute angles) formed by the straight line connecting the w-axis and the point C and the intersection of the laser line and the Ω plane are expressed by α1 and α2, respectively. If d2 <d1, then α1 <α2. As the distance from the point O to the reflector R increases in this way, the above angle decreases. The above angle corresponds to the azimuth angle described later.

FIG. 9 is a diagram for explaining how to obtain the distance l from the point C to the point L. The angle α is an angle (acute angle) formed by the straight line CLw (w axis) connecting the point C and the point Lw and the straight line CLu connecting the point C and the point Lu, and is called the azimuth angle of the measurement point L. The angle β is an angle (acute angle) formed by the straight line CLu connecting the point C and the point Lu and the straight line CL connecting the point C and the point L, and is called the elevation / depression angle of the measurement point L. Conclusion The point P1 and the point P2 in FIG. 8, a straight line passing through the point P ₀ corresponds to a line of intersection of two planes of the plane Σ and the surface π in FIG.

In FIG. 9, the length of the line segment connecting the two points is defined as follows.

| CL | = l, | CLu | = lu, | CLw | = w, | LwLu | = u, | LwLv | = v, | CO | = d

Here, for example, | CL | represents the length of the line segment connecting the points C and L. In addition, the angle formed by the two line segments is defined as follows.

∠LwCLu = α, ∠LCLu = β, ∠CP ₀ O = γ, ∠CLuO = η
∠LuCO = φ, ∠LuOC = ξ, ∠OC P ₀ = π / 2

Here, for example, ∠LwCLu represents the angle formed by the line segment connecting the point C and the point Lw and the line segment connecting the point C and the point Lu.

点Ｃ、点Ｐ０及び点Ｏを頂点とする三角形について以下の関係が成立する。

点Ｃ、点Ｌｕ及び点Ｏを頂点とする三角形について以下の関係が成立する。

点Ｃ、点Ｌｕ及び点Lを頂点とする三角形について以下の関係が成立する。

式（１）-（３）を使用して式（４）からｌｕを消去して整理すると以下の式が得られる。

ここで、距離ｄ及び角度γは固定値であるので、測定点Ｌの方位角α及び測定点Ｌの仰俯角βを求めることによって式（１）-（５）を使用して点Ｃと測定点Ｌとの距離ｌを求めることができる。 The following relationship holds for triangles having points C, P0, and Lu as vertices.

The following relationship holds for a triangle whose vertices are point C, point P0, and point O.

The following relationship holds for triangles having points C, Lu, and O as vertices.

The following relationship holds for points C, Lu, and triangles having points L as vertices.

The following equation can be obtained by eliminating lu from the equation (4) and rearranging it using the equations (1)-(3).

Here, since the distance d and the angle γ are fixed values, the azimuth angle α of the measurement point L and the elevation / depression angle β of the measurement point L are obtained to measure the distance d and the angle γ with the point C using equations (1)-(5). The distance l from the point L can be obtained.

When an electric furnace for steelmaking is used as a measurement target, the distance d is preferably 500 mm to 1500 mm, and the angle γ is preferably 8 to 23 degrees.

第１のカメラ１０３の画像上の全ての画素に対して座標（ｕ，ｖ）から方位角α及び仰俯角βを定める。一般的にカメラまたはレンズを変えるごとに上記の手順によって画像上の全ての画素に対して方位角α及び仰俯角βを定める必要がある。 FIG. 10 is a diagram for explaining a method of determining the azimuth angle α of the measurement point L and the elevation / depression angle β of the measurement point L from the image of the first camera 103. The field center axis of the first camera 103 and the y-axis, a plate [pi _uv having a u direction and the v direction grid orthogonal to each other, flat [pi _uv is orthogonal to the y-axis, a principal point of the first camera 103 Arrange so that the distance from C is w and the u direction is the horizontal direction of the image. When the coordinates of an arbitrary point L on the flat plate π _uv are expressed by (u, v), the azimuth angle α and the elevation / depression angle β of the point L can be expressed by the following equations.

The azimuth angle α and the elevation / depression angle β are determined from the coordinates (u, v) for all the pixels on the image of the first camera 103. Generally, every time the camera or lens is changed, it is necessary to determine the azimuth angle α and the elevation / depression angle β for all the pixels on the image by the above procedure.

FIG. 11 is a flow chart showing a method of determining the shape of the inner circumference of the furnace wall in the reference state using the image of the laser line described in step S1020 of FIG.

In step S2010 of FIG. 11, the processor 110 determines the azimuth α and the elevation / depression angle β of the measurement point L on the laser line in the image of the laser line of the first camera 103.

In step S2020 of FIG. 11, the processor 110 obtains the distance l from the principal point C of the first camera 103 to the measurement point L using the azimuth angle α, the elevation / depression angle β, and equations (2)-(5). .. Since the measurement point L is a point on the furnace wall 310, the shape of the furnace wall 310 is determined from the distance l, the azimuth angle α, and the elevation / depression angle β.

FIG. 12 is a diagram showing the relationship between the azimuth angle α, the elevation / depression angle β of the measurement point L, and the distance l from the principal point C of the first camera 103 to the measurement point L. The horizontal axis of FIG. 12 represents the azimuth angle α of the measurement point L. The unit is degrees. The vertical axis of FIG. 10 represents the distance l from the principal point C of the first camera 103 to the measurement point L. The unit is 10 centimeters (1 centimeter). FIG. 12 shows the relationship between the azimuth α and the distance l for six different values of the elevation / depression angle β. The numerical values of the azimuth α, the elevation / depression angle β, the angle γ, and the distance d are as follows.
α = -1.0 to +1.0 deg
β = 0 to 30 deg
γ = 13 deg
d = 800 mm

According to FIG. 12, the average gradient of the distance with respect to the azimuth is 300 (mm / deg). As described above, the azimuth decreases as the distance increases. If the horizontal viewing angle of the first camera 103 is 60 degrees and the number of horizontal pixels is 1200, the distance resolution is
300 / (1200/60) = 15 (mm / pixel)
Will be.

In the present embodiment, in order to simplify the calculation for obtaining the distance l, the point O is located on the u axis and the surface π is orthogonal to the surface Ω. In general, even when the point O is not located on the u-axis and the surface π is not orthogonal to the surface Ω, the azimuth angle α of the measurement point, the elevation / depression angle β of the measurement point, and the center axis and surface of the field of view of the first camera 103 The distance l can be obtained from the positional relationship with π.

FIG. 13 is a diagram showing the shape of the inner circumference of the furnace wall in the reference state measured by the furnace wall shape / wear measuring device 100. The horizontal axis of FIG. 13 indicates the position along the inner circumference of the furnace wall at the height of the slag line. This position corresponds to the rotation angle around the axis of rotation. In FIG. 13, the positions of the steel outlet and the slag outlet are shown along the horizontal axis. The vertical axis of FIG. 13 shows the distance l from the principal point C of the first camera 103 to the measurement point L of the height of the slag line on the furnace wall, that is, the shape of the furnace wall at the height of the slag line. The upward direction on the vertical axis indicates the direction of wear of the furnace wall. The downward direction on the vertical axis indicates the direction of deposition of castable refractory material. The scale on the vertical axis is 20 millimeter.

The thick line in the horizontal axis direction in FIG. 13 is the average value of the distance l between the steel outlet and the slag outlet in the reference state, that is, in the state where the furnace wall is not worn.

FIG. 14 is a flow chart showing a method of determining the shape and wear of the inner circumference of the furnace wall 310 after steel removal. After steel removal is the period from the completion of the process of inputting raw materials, melting of raw materials, steel ejection and slag, to the start of the next process. According to this embodiment, by using the laser line as a mark by a light beam, the shape and wear of the furnace wall can be measured in a short time while the furnace is in a high temperature state after steel removal.

In step S3010 of FIG. 14, the first camera 103 and the second camera 105 acquire an image of the laser line on the inner circumference of the furnace wall after steel removal and an image of the inner circumference of the furnace wall after steel removal, respectively.

In step S3020 of FIG. 14, the processor 110 uses the image of the laser line to determine the shape of the inner circumference of the furnace wall after steel removal. The procedure for determining the shape of the inner circumference of the furnace wall after steel removal is the same as the procedure shown in FIG.

FIG. 15 is a diagram showing the shape of the inner circumference of the furnace wall after steel removal measured by the furnace wall shape / wear measuring device 100. The horizontal axis of FIG. 15 indicates the position along the inner circumference of the furnace wall at the height of the slag line. In FIG. 15, the positions of the steel outlet and the slag outlet are shown along the horizontal axis. The vertical axis of FIG. 15 shows the distance l from the principal point C of the first camera 103 to the measurement point L of the height of the slag line on the furnace wall, that is, the shape of the furnace wall at the height of the slag line. The upward direction on the vertical axis indicates the direction of wear of the furnace wall. The downward direction on the vertical axis indicates the direction of deposition of castable refractory material. The scale on the vertical axis is 20 millimeter.

The thick line in the horizontal axis direction of FIG. 15 shows the average value of the distance l between the steel outlet and the slag outlet in the reference state, that is, in the state where the furnace wall is not worn, as in FIG.

The measurement of FIG. 15 was performed about 2 months after the reference state shown in FIG. During this period, repairs between processes by the repair machine were repeatedly carried out. According to FIG. 15, the amount of wear is particularly large in the two circled portions near the slag outlet.

The amount of wear of the furnace wall may be obtained from the difference between the distance l after steel removal and the distance l in the reference state for each position along the inner circumference of the furnace wall.

In step S3030 of FIG. 14, the processor 110 generates a composite image in which information indicating the shape and wear of the inner circumference of the furnace wall after steel removal is added to the image of the inner circumference of the furnace wall after steel removal.

In step S3040 of FIG. 14, the processor 110 displays on the display 120 a composite image in which information indicating the shape and wear of the inner circumference of the furnace wall after steel removal is added to the image of the inner circumference of the furnace wall.

FIG. 16 is a diagram showing an image of the inner circumference of the furnace wall and an image of the laser line separately. In the image of the laser line on the right side of FIG. 16, the right direction shows the wear direction of the furnace wall.

FIG. 17 is a diagram showing a composite image in which an image of a laser line is superimposed on an image of the inner circumference of the furnace wall. In FIG. 17, the laser line measured in the reference state (described as “reference line” in the figure) is shown by a solid line, and the laser line measured between processes (described as “wear line” in the figure) is shown by a broken line. Since the movement of the laser line to the right indicates wear, it is possible to efficiently repair the furnace wall by depositing castable refractory material at the location where the wear line is moving to the right compared to the reference line. it can. The part where the wear line moves to the left as compared with the reference line is the part where the castable refractory is deposited thicker than the reference state. The image of the laser line may be a magnified view of the horizontal change with respect to the length so that the change in the position of the furnace wall can be easily understood. The magnification may be in the range of 3 to 10 times. A number indicating the amount of wear of the portion corresponding to the image of the laser line may be superimposed. By creating and displaying an image in which information indicating the shape and wear of the furnace wall is added to the image of the furnace wall in this way, efficient repair of the furnace wall becomes possible.

A composite image may be generated based on the images acquired simultaneously by the first camera 103 and the second camera 105 during rotation. Alternatively, the amount of wear or the laser line image at each position in the circumferential direction is obtained in advance based on the image acquired by the first camera 103 during rotation, and when the repair is performed by the repair machine 200, the second camera 105 is used. An image of the furnace wall at the location to be repaired may be acquired, and a composite image may be generated from the amount of wear or the laser line image at the position in the circumferential direction corresponding to the image. The operator can appropriately repair the furnace wall by the repair machine 200 by referring to the above image.

The above description relates to an embodiment in which a laser line generator is used as a light source and a laser line is used as a mark by a light beam. As described above, by using the laser line as a mark by light rays, it is possible to carry out the measurement in a short time while the furnace is in a high temperature state between the processes of the furnace. Embodiments using other light sources will be described below. As a light source, a projector that irradiates a furnace wall with a pattern such as a stripe or a grid by an LED light beam may be used. Such projectors are sold, for example, by Opto Engineering (trade name LTPRSMHP3W SERIES). The shape and wear of the furnace wall can be determined by generating a line or a plurality of dots arranged on the line on the intersection line between the surface including the light emitting point and the surface of the furnace wall by the above projector, as in the case of using the laser line. Measurements can be performed. When using a laser line, two cameras, a camera that collects an image of the laser line and a camera that collects an image of the furnace wall, are required, but in this embodiment, a single camera is used to mark and furnace with light rays. Images of the wall can be taken. In addition, any light source capable of producing marks by light rays, such as lines or dots arranged on the lines, can be used in the present invention.

Claims (12)

A furnace wall shape / wear measuring device used in a furnace having a central axis and having a circular furnace wall having a cross section perpendicular to the central axis having a center on the central axis.
A light source for generating a mark by light rays on the furnace wall, a first camera for acquiring an image of the mark, and a processor are provided.
The light source and the first camera are installed in the vicinity of the central axis and are configured to be rotatable around a rotation axis in the direction of the central axis.
The light emitting point O of the light source is substantially located on the rotation axis, and the light source is configured to generate the mark on the intersection of the first plane including the light emitting point O and the surface of the furnace wall. Being done
When the light source and the first camera rotate around the rotation axis while maintaining a relative positional relationship, the first plane is configured to rotate around the rotation axis.
The w-axis is on the central axis of the field of view of the first camera, the principal point C of the first camera on the w-axis is the origin, and the origin is included and orthogonal to each other in a plane perpendicular to the w-axis. With the straight line as the u-axis and v-axis
The processor obtains the azimuth angle and elevation / depression angle of the measurement point from the u and v coordinates of the measurement point on the mark in the image acquired by the first camera rotating around the rotation axis, and the azimuth angle. From the elevation / depression angle and the relative positional relationship between the central axis of the field of view and the first plane, the distance between the main point C and the measurement point and the direction from the main point C to the measurement point are determined. The shape and wear of the furnace wall configured so that the shape and wear of the furnace wall can be determined from the distance between the main point C and the measurement point and the direction from the main point C to the measurement point. measuring device. The shape / wear measuring device for a furnace wall according to claim 1, wherein the first plane is orthogonal to a plane formed by the u-axis and the w-axis. The shape / wear measuring device for a furnace wall according to claim 1 or 2, wherein the light emitting point O is located on the u-axis. Let d be the distance between the point C and the point O, P ₀ be the intersection of the w axis and the first surface, and γ be the acute angle formed by the straight line connecting the w axis and the point O and the point P _0. The shape / wear measuring device for a furnace wall according to claim 3, wherein the range is from 500 mm to 1500 mm and the γ is in the range of 8 to 23 degrees. The shape / wear measuring device for a furnace wall according to any one of claims 1 to 4, wherein the light source is a laser line generator that emits a laser beam into the first plane, and the mark is a laser line. The shape / wear measuring device for a furnace wall according to claim 5, which is configured so that the direction of a laser beam emitted by the laser line generator can be changed. A second camera for acquiring an image of the furnace wall and a display are further provided.
The second camera is installed in the vicinity of the central axis so that an image of the furnace wall can be acquired along the inner circumference of the furnace wall, and is configured to be rotatable around the rotation axis. ,
The furnace wall according to claim 5 or 6, wherein the processor creates an image in which information indicating the shape and wear of the furnace wall is added to an image of the furnace wall, and is displayed by the display. Shape / wear measuring device. The shape / wear measuring device for a furnace wall according to any one of claims 1 to 4, wherein the light source is a projector, and the mark is a mark generated by the projector. The shape / wear measuring device for a furnace wall according to any one of claims 1 to 7, wherein the light source and the first camera are rotatably installed in the vicinity of the central axis of the furnace wall repair machine. .. A method for measuring the shape and wear of a furnace wall used in a furnace having a central axis and having a circular furnace wall having a cross section perpendicular to the central axis having a center on the central axis. A light source that generates a mark by light rays on the furnace wall, a first camera that acquires an image of the mark, and a processor are used, and the light source and the first camera are installed in the vicinity of the central axis. The light emitting point O of the light source is substantially located on the rotation axis, and the light source has a first plane including the light emitting point O, which is configured to be rotatable around a rotation axis in the direction of the central axis. It is configured to generate the mark on the intersection with the surface of the furnace wall, and includes the mark when the light source and the first camera rotate around the rotation axis while maintaining a relative positional relationship. The first surface is configured to rotate around the rotation axis, the w-axis is on the center axis of the field of view of the first camera, and the main point C of the first camera on the w-axis is the origin. In the method, the two straight lines including the origin and perpendicular to each other in the plane perpendicular to the w-axis are defined as the u-axis and the v-axis.
A step of acquiring an image of the mark along the inner circumference of the furnace wall while rotating the light source and the first camera around the rotation axis.
A step of obtaining the azimuth angle and elevation / depression angle of the measurement point from the u and v coordinates of the measurement point on the mark in the image by the processor.
From the azimuth angle, the elevation / depression angle, and the relative positional relationship between the central axis of the field of view and the first plane, the distance between the main point C and the measurement point and the main point C. A furnace wall including a step of determining a direction toward the measurement point, a distance between the main point C and the measurement point, and a step of determining the shape and wear of the furnace wall from the direction from the main point C toward the measurement point. Shape / wear measurement method. Further using a second camera and an indicator to acquire an image of the furnace wall, the second camera is installed near the central axis in the direction of the axis of rotation and rotates around the axis of rotation. Possible to be configured
The step of acquiring an image of the furnace wall along the inner circumference of the furnace wall by the second camera, and
A step in which the processor creates an image in which information indicating the shape and wear of the furnace wall is added to the image of the furnace wall.
The shape / wear measurement of the furnace wall according to claim 10, further comprising a step in which the processor displays an image of the furnace wall in which information indicating the shape / wear of the furnace wall is added by the display device. Method. The furnace is based on the difference between the distance between the measurement point and the first camera determined when the furnace wall is in the reference state and the distance between the newly determined measurement point and the first camera. The method for measuring the shape and wear of a furnace wall according to claim 10 or 11, wherein the amount of wear of the wall is determined.

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