METHOD FOR DETECTING SURFACE PROFILE OF CHARGE IN A BLAST FURNACE, OBJECT DETECTION DEVICE THEREFOR, AND METHOD FOR OPERATING A BLAST FURNACE

Abstract

To more accurately detect a surface profile of a burden 20 by eliminating a distance signal generated in the vicinity of an inner wall 1a of a blast furnace 1 and reflected by both the inner wall 1a and the burden 20.SOLUTION: When detecting a surface profile of a burden 20 in a blast furnace 1, the relationship (Z-R) between a height (Z) of the blast furnace 1 and a radius (R) of the blast furnace 1 at the height (Z) is obtained in advance. A distance (Rp) of a measurement point P to the axis line of the blast furnace 1 at a height coordinate (Pz) of the measurement point P is compared with a radius (R') of the blast furnace 1 at the same height as the coordinate (Pz) determined from the relation (Z-R). When (Rp) is greater than (R'), the measurement point P is removed from the actually measured range signal group.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for detecting a surface profile of a charge in a blast furnace and an object detection device therefor. The present invention also relates to a method for operating a blast furnace using the method for detecting a surface profile or the object detection device. [Background technology]

[0002] The surface profiles of iron ore, coke, and lime (hereinafter collectively referred to as "charge materials") supplied into a blast furnace are detected, and charge materials are replenished based on the surface profiles of the charge materials to ensure stable operation. In a blast furnace, the charge materials are appropriately piled and the gas flow in the furnace is stabilized, thereby reducing fuel costs and extending the life of the blast furnace. In order to obtain an appropriate piled state, it is necessary to accurately measure the surface profiles of these charge materials in a short time and replenish the charge materials so that the theoretical piled state obtained in advance, i.e., the "theoretical piled profile", is obtained. Since the inside of the furnace is at high temperature and steam and part of the charge materials are floating, microwaves or millimeter waves are suitable as detection waves.

[0003] In order to detect the surface profile of such a charge in a blast furnace, the present applicant has previously proposed an object detection device as shown in Patent Document 1 and Patent Document 2. In both object detection devices, a detection wave is transmitted into the inside of the blast furnace by a reflector, and the inclination angle of the reflecting surface of the reflector toward the blast furnace side is variable, and the rotating plate on which the reflector is installed in the object detection device of Patent Document 1 and the guide pipe on which the reflector is installed in Patent Document 2 are made rotatable in the circumferential direction around their axis, and the inclination angle of the reflector and the rotation angle of the rotating plate and the guide pipe are controlled to scan the surface of the charge linearly or planarly, and the reflected detection wave is received to detect the surface profile of the charge linearly or planarly. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 241008 [Patent Document 2] Patent No. 5391458 Summary of the Invention [Problem to be solved by the invention]

[0005] Figure 1 is a schematic diagram showing the transmission and reception of a detection wave M in an object detection device. The detection wave M is transmitted from point a of the object detection device 100 installed at an opening 2 near the top of the blast furnace 1 toward the charge 20 in the furnace, the detection wave M reflected by the surface of the charge 20 is incident on point a of the object detection device 100, and the distance from point a to the reflection position of the detection wave M is detected.

[0006] At that time, in the vicinity of the inner wall of the blast furnace 1, the detection wave M is reflected at point b of the inner wall 1a and then enters the surface of the charge 20. Then, the detection wave Mb reflected at point b of the inner wall 1a enters the charge 20a located near the inner wall 1a, for example, at point c on the surface of the charge 20, and the reflected wave Mbr reaches point b of the inner wall 1a, is reflected at point b, and is received by the object detection device 100. The charge 20, which is iron ore, coke, and lime, is a granular material with a diameter of several centimeters, and the detection wave Mb that enters the charge 20a also returns in the direction of entry into the charge 20a, like the reflected wave Mbr. The propagation path of the detection wave M at this time is shown by a dotted line, and is the sum (propagation distance L1) of the points a to b and the point b to c.

[0007] On the other hand, when the detection wave M from point a of the object detection device 100 travels straight without being reflected at point b of the inner wall 1a, the propagation path of the detection wave M extends from point a to point b to the outside of the blast furnace 1. Then, on the propagation path, a position outside the furnace by a distance equivalent to point c from point b is point d. The propagation path of the detection wave M at this time is the straight-line distance from point a to point d (propagation distance L2), which is the same distance as the propagation distance L1. Therefore, in the object detection device 100, it is received as a distance signal from point d equivalent to the propagation distance L2.

[0008] Thus, the surface profile of the charge 20, especially in the vicinity of the inner wall 1a of the blast furnace 1, may not be measured accurately.

[0009] The present invention has been made in consideration of the above circumstances, and aims to eliminate measurement points outside the blast furnace 1 and more accurately detect the surface profile of the charge. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides a method for detecting a surface profile of a charge in a blast furnace, an object detection device, and a method for operating a blast furnace, as described below. (1) A method for detecting a surface profile of a burden material, comprising: transmitting a detection wave from an antenna toward a burden material accumulated inside a blast furnace; scanning a surface of the burden material in a planar or linear manner; receiving the detection wave reflected by the surface of the burden material with the antenna; measuring a distance to the burden material; and detecting a surface profile of the burden material based on the distance signal, Based on a preset relationship between the height (Z) of the blast furnace and the radius (R) of the blast furnace at the height (Z), A method for detecting a surface profile of a charge in a blast furnace, comprising removing from a group of actually measured distance signals distance signals whose distance from the center of the blast furnace is greater than the radius (R) at the height (Z). (2) An object detection device that transmits a detection wave from an antenna toward a burden piled up inside a blast furnace, scans the surface of the burden in a planar or linear manner, receives the detection wave reflected from the surface with the antenna, measures the distance to the burden, and detects a surface profile of the burden based on the distance signal, Based on a preset relationship between the height (Z) of the blast furnace and the radius (R) of the blast furnace at the height (Z), An object detection device characterized in that the distance signal whose distance from the center of the blast furnace is greater than the radius (R) at the height (Z) is deleted from a group of actually measured distance signals. (3) A method for operating a blast furnace, comprising controlling the supply of the charge material using the object detection device according to (2) above. Effect of the Invention

[0011] According to the present invention, since the measurement points outside the blast furnace are eliminated, the surface profile of the charge can be detected more accurately, and good operation of the blast furnace can be stably performed. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing an outline of an object detection device used to detect the surface profile of a blast furnace charge. [Diagram 2] FIG. 2 is a plan view showing the surface profile of the charge obtained when a distance signal from point d located outside the inner wall 1a is included. [Diagram 3] FIG. 3 is a plan view showing the surface profile of the charge obtained when the distance signal outside the inner wall 1a is omitted. [Figure 4] FIG. 4 is a cross-sectional view showing an example of an object detection device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention will now be described in detail with reference to the drawings.

[0014] As explained in Fig. 1, when trying to measure the burden material 20 near the inner wall 1a of the blast furnace 1, a distance signal is also received from a position (e.g., point d) outside the blast furnace 1. The measurement result is shown in Fig. 2, which shows the entire surface of the burden material 20 piled up in the blast furnace 1. In the figure, the inner wall 1a of the blast furnace 1 is shown as a circle, and the object detection device 100 is installed in the upper right corner of the figure.

[0015] In the figure, there are a large number of measurement points (indicated by diagonal lines in the figure) inside the circle (inner wall 1a), and the surface profile of the charge 20 is measured. In addition, many measurement points S are scattered on the left outer side of the inner wall 1a, and these measurement points S correspond to points d in Figure 1. The further to the left of the inner wall 1a, the more likely it is that measurement points will appear on the outer side of the inner wall 1a.

[0016] Therefore, as shown in Fig. 3, the measurement point S on the outside of the inner wall 1a is deleted. To delete the measurement point S, first, the relationship (ZR) between the height (Z) of the blast furnace 1 and the radius (R) of the blast furnace 1 at this height (Z) is obtained. The relationship (ZR) between the height (Z) and the radius (R) of the blast furnace 1 may be actually measured by the object detection device 100 when the blast furnace 1 is empty, or may be obtained from the design specifications of the blast furnace 1.

[0017] Next, the surface of the load 20 is scanned in the X and Y directions by the object detection device 100 to obtain position information (X, Y, Z) at each measurement point in the X direction (left-right direction on the paper) and Y direction (up-down direction on the paper), as well as in the height (Z) direction (front-back direction on the paper).

[0018] At this time, the coordinates (Px, Py, Pz) of a measurement point P (for example, symbol P in FIG. 2) outside the blast furnace 1 are a distance signal of the detection wave M transmitted from point a of the object detection device 100, reflected by the inner wall 1a and the charge 20, and returning to point a. Also, as shown in FIG. 2, if the distance from the axis of the blast furnace 1 to the measurement point P, i.e., the radius, is Rp, the radius (Rp) becomes larger than the actual radius (R') of the blast furnace 1 at the same height as Pz obtained from the relationship (ZR), and this measurement point P is determined to be outside the blast furnace 1 and is deleted.

[0019] By dividing the measurement points inside and outside the inner wall 1a of the blast furnace 1 in this manner, a clearer and more accurate surface profile of the charge 20 can be obtained, as shown in FIG.

[0020] The above-mentioned detection method for removing distance signals from charges located outside the blast furnace 1 can also be applied to, for example, the object detection device shown in Patent Document 1. For details of the device, refer to Patent Document 1, and the main parts of the device are shown here.

[0021] As shown in Fig. 4, the object detection device 100 is installed at an opening 2 near the top of a blast furnace 1. The object detection device 100 includes a rotating plate 120 that rotates horizontally relative to the opening 2 of the blast furnace 1 as indicated by the symbol Y. The rotating plate 120 is an annular disk having an opening 121 in the center. A cylindrical rotating shaft 110 is attached to the rotating plate 120, and an antenna 135 is housed inside the rotating shaft 110. The rotating plate 120 is attached concentrically with the opening 121 of the rotating plate 120.

[0022] The antenna 135 is connected to the transmitting / receiving means 130 of the detection wave M via a waveguide 133. The waveguide 133 has a separation portion 180 at its upper end portion on the transmitting / receiving means 130 side, so that the transmitting / receiving means 130 does not rotate. The waveguide 133 coincides with the axis of the rotating shaft 110. A dielectric lens 136 may be attached to the antenna 135 to increase the directivity of the detection wave M.

[0023] A gear 112 is provided on the outer circumferential surface of the rotating shaft 110, and a gear 155 of a motor 113 is engaged with the gear 112. Therefore, by driving the motor 113, the rotating shaft 110 rotates as indicated by the symbol Y in the figure, and the rotating plate 120 rotates horizontally with respect to the opening 2 of the blast furnace 1 in the same direction as the rotating shaft 110.

[0024] In the space below the rotating plate 120 and between it and the opening 2 of the blast furnace 1, a fixed angle reflector 138 and a variable angle reflector 140 are arranged for transmitting and receiving detection waves M into the furnace.

[0025] The fixed angle reflector 138 is a reflector whose reflecting surface has a fixed inclination angle of 45°, and is composed of a first fixed angle reflector 138A, a second fixed angle reflector 138B, and a third fixed angle reflector 138C. The first fixed angle reflector 138A faces the antenna surface of the antenna 135 through the opening 121 of the rotating plate 120. The second fixed angle reflector 138B faces the first fixed angle reflector 138A, and the third fixed angle reflector 138C faces the second fixed angle reflector 138B. Therefore, as shown by the dashed line in the figure, the detection wave M transmitted from the antenna 135 is reflected by the first fixed angle reflector 138A and sent to the second fixed angle reflector 138B, and then reflected by the second fixed angle reflector 138B and sent to the third fixed angle reflector 138C. The light is then reflected by the third fixed angle reflector 138C and sent to the variable angle reflector 140.

[0026] The first fixed angle reflector 138A, the second fixed angle reflector 138B, and the third fixed angle reflector 138C are attached to a fixed member (not shown) that hangs down from the rotating plate 120 toward the opening 2 of the blast furnace 1. Alternatively, the first fixed angle reflector 138A, the second fixed angle reflector 138B, and the third fixed angle reflector 138C are attached to a side wall 170 that extends from the rotating plate 120 toward the opening 2 of the blast furnace 1 and is attached to the periphery of the rotating plate 120.

[0027] As the detection wave M, microwaves or millimeter waves are used since the inside of the furnace is hot and dust and water vapor are present.

[0028] The angle-variable reflector 140 is a reflector in which the inclination angle of the reflecting surface 140a can be changed in the direction indicated by the symbol X in the figure. In this angle-variable reflector 140, a first link 117a of a link mechanism 117 is fixed to the center of the surface (back surface) opposite to the reflecting surface 140a, and a second link 117b is connected to the first link 117a. In addition, a connecting rod 114 that penetrates the inside of the rotating shaft 110 through an opening 121 of the rotating shaft 110 is connected to the second link 117b, and a rack gear 118 is formed on the end of the connecting rod 114 opposite to the second link 117b.

[0029] The connecting rod 114 has an outer tube portion 114a having a waveguide 133 as an inner tube that connects the antenna 135 and the transmitting / receiving means 130, and a rack gear 118 is formed on the outer circumferential surface of the outer tube portion 114a. A gear 119 of a motor 125 meshes with this rack gear 118, and by driving the motor 125, the gear 119 rotates, which is converted into linear motion by the rack gear 118. An encoder 126 is connected to the motor 125, and the amount of rotation of the motor 125 and further the amount of rotation of the gear 119 are detected.

[0030] Moreover, the connecting rod 114 has an intermediate portion 114b that extends toward the rotating plate 120 inside the rotating shaft 110 so as to avoid the antenna 135. The end of the outer tube portion 114a on the rotating shaft 110 side is bent outward, and the intermediate portion 114b is continuous with this bent portion. The intermediate portion 114b has a lower end portion 114c that extends to the opening 2 of the blast furnace 1 through the opening 121 of the rotating plate 120. This lower end portion 114c is connected to a second link 117b of the link mechanism 117.

[0031] The connecting rod 114 is configured in this manner, and the rotation of the motor 125 is converted into linear motion by the rack gear 118 via the gear 119, so that the connecting rod 114 moves linearly to the side of the angle-variable reflector 140 or to the opposite side, as shown by the symbol H in the figure.

[0032] When the connecting rod 114 moves toward the angle variable reflector 140 (descending in the figure), the reflecting surface 140a of the angle variable reflector 140 is inclined via the link mechanism 117 so as to face the inner wall of the blast furnace 1, and when the connecting rod 114 moves away from the angle variable reflector 140 (rising in the figure), the reflecting surface 140a of the angle variable reflector 140 is inclined via the link mechanism 117 so as to face the axis of the blast furnace 1. That is, by the descent and ascent of the connecting rod 114, the inclination of the reflecting surface 140a of the angle variable reflector 140 can be changed in the direction of the symbol X in the figure.

[0033] Accordingly, the detection wave M sent from the third fixed angle reflector 138C of the fixed angle reflector 138 to the variable angle reflector 140 is oscillated in the left-right direction in the figure as shown by the symbol Z, and is sent into the furnace in the form of a line along the radial direction of the rotating plate 120.

[0034] The detection wave M is reflected by the surface of the charge material accumulated in the furnace and is received by the transmission / reception means 130 via the same path as when it was transmitted. Transmission and reception are performed by the FMCW method, and the detection wave M transmitted from the antenna 135 connected to the transmission / reception means 130 is reflected by the fixed angle reflectors 138A-138C and sent to the variable angle reflector 140, and the detection wave M (transmission wave) transmitted from the variable angle reflector 140 at a predetermined angle is sent into the furnace through the opening 2 of the blast furnace 1, and then reflected by the surface of the charge material, and the reflected wave is detected by the transmission / reception means 130 via the reverse path (variable angle reflector 140 → fixed angle reflectors 138C-138A → antenna 135 → transmission / reception means 130). Then, distance information between the transmission / reception means 130 and the surface of the charge material is obtained from the frequency difference (beat frequency) between the transmission wave and the reflected wave.

[0035] By transmitting and receiving this linear detection wave M while rotating the rotating plate 120 about the rotating shaft 110, distance information in a circular scanning area covering the entire interior of the blast furnace 1 can be obtained.

[0036] At this time, the rotation angle of the rotating shaft 110 corresponding to the rotation position of the rotating plate 120 is detected by the encoder 150 connected to the motor 113, and thus position information of the detection wave M in the scanning area is obtained. In addition, the inclination angle of the reflecting surface 140a of the angle-variable reflecting plate 140 is detected from the rotation amount of the motor 125 and the gear 119 by the encoder 126, and the position information in the radial direction of the rotating plate 120 is detected. From the distance information and position information, a surface profile of the entire surface of the charge material is obtained.

[0037] Then, the position coordinates (Px, Py, Pz) of a certain measurement point P (for example, symbol P in FIG. 2) are calculated from the distance signal at that point and the tilt angle of the reflector. The actual radius (R') of the blast furnace 1 determined in advance at the height (Pz) of the measurement point at this time is compared with the radius (Rp) from the center of the blast furnace 1 of the measurement point P at this height (Pz). If the radius (Rp) at this measurement point P is larger than the radius (R') of the blast furnace 1, this measurement point is deemed to be outside the blast furnace 1 and is deleted.

[0038] In this manner, the correction circuit 200 deletes the measurement points outside the blast furnace 1. The correction circuit 200 is connected to the transmitting / receiving means 130, and deletes the measurement points outside the blast furnace 1 from the data of the surface profile of the entire surface of the charge 20, and displays it on a display device (not shown) or the like.

[0039] As described above, according to the present invention, the distance signal that occurs near the inner wall 1a of the blast furnace 1 and is reflected by both the inner wall 1a and the charge 20 can be eliminated, thereby making it possible to more accurately detect the surface profile of the charge 20. [Explanation of symbols]

[0040] 1 blast furnace 1a Inner wall 2 Opening 100 Object detection device 114 Connecting rod 117 Link mechanism 120 Rotating Plate 126 Encoder (X direction) 130 Means of transmission and reception 135 Antenna 138, 138A, 138B, 138C fixed angle reflector 140 Variable Angle Reflector 150 Encoder (Y direction) 200 Correction circuit

Claims

1. A method for detecting a surface profile of a burden material, comprising: transmitting a detection wave from an antenna installed near the top of a blast furnace toward a burden material accumulated inside the blast furnace; scanning a surface of the burden material in a planar or linear manner; receiving the detection wave reflected from the surface by the antenna to measure a distance to the burden material; and detecting a surface profile of the burden material based on the distance signal, The relationship (Z-R) between the height (Z) of the blast furnace and the radius (R) of the blast furnace at the height (Z) is obtained in advance, The distance (Rp) of the measurement point P to the axis of the blast furnace at the height coordinate (Pz) of the measurement point P; The coordinate (Pz) calculated from the relationship (Z-R) is compared with the radius (R') of the blast furnace at the same height, A method for detecting a surface profile of a blast furnace charge, characterized in that when (Rp) is greater than (R'), the measurement point P is deleted from the group of distance signals actually measured.

2. An object detection device which transmits detection waves from an antenna installed near the top of a blast furnace toward charges piled up inside the blast furnace, scans the surface of the charges in a planar or linear manner, receives the detection waves reflected from the surface with the antenna to measure the distance to the charges, and detects a surface profile of the charges based on the distance signal, The relationship (Z-R) between the height (Z) of the blast furnace and the radius (R) of the blast furnace at the height (Z) is obtained in advance, The distance (Rp) of the measurement point P to the axis of the blast furnace at the height coordinate (Pz) of the measurement point P; The coordinate (Pz) calculated from the relationship (Z-R) is compared with the radius (R') of the blast furnace at the same height, An object detection device characterized in that, when (Rp) is greater than (R'), the measurement point P is deleted from the group of distance signals actually measured.

3. A method for operating a blast furnace, comprising the steps of: controlling the supply of the burden material by using the object detection device according to claim 2.

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