Blast furnace condition measurement device and blast furnace operation method

Abstract

To accurately measure a surface profile of a charged material, a temperature distribution and a gas concentration distribution in a furnace by a single measurement device when monitoring a furnace condition.SOLUTION: The present invention relates to a blast furnace condition measurement device configured to perform scanning with a laser beam toward the inside of a blast furnace to measure a surface profile of a burden being deposited and a temperature distribution and a gas concentration distribution in a space above a surface of the burden, and to have light emitting and receiving means configured to emit and receive the laser beam. The present invention also relates to a method for operating a blast furnace while adjusting operation conditions based on the surface profile of the burden, and the temperature distribution and the gas concentration distribution in the space above the surface of the burden, using the blast furnace condition measurement device.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus for measuring the surface profile of a burden material in a blast furnace, which is an indicator of the furnace condition of the blast furnace, as well as the temperature distribution and gas concentration distribution in the space above the surface of the burden material.The present invention also relates to a method for operating a blast furnace. [Background technology]

[0002] Monitoring the furnace conditions is extremely important for maintaining stable operation in a blast furnace. In particular, there is a close relationship between the surface profile, which indicates the deposition state of iron ore and coke (hereinafter collectively referred to as "burden"), and the temperature distribution and gas concentration distribution in the space above the burden surface. By monitoring these and correlating and analyzing the obtained information, the furnace conditions can be grasped early and accurately.

[0003] Conventionally, furnace conditions have been monitored using various measuring devices, such as a burden surface profile measuring device (see Patent Document 1) that measures the deposition state of burden materials using electromagnetic waves such as microwaves and millimeter waves, a furnace top temperature distribution measuring device (see Patent Document 2) that measures the temperature distribution in the furnace top space from the propagation speed of sound waves by placing an acoustic sensor on the circumference of the blast furnace, and a gas analyzer that measures gas at the furnace top by inserting a gas sampling tube and a thermocouple (see Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6857933 [Patent Document 2] Japanese Patent Application Publication No. 2019-183262 [Patent Document 3] Japanese Patent Application Publication No. 8-193209 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the burden surface profile measuring device described in Patent Document 1 is suitable for measuring the surface profile of the burden, but cannot measure the temperature or gas concentration in the furnace top space. The furnace top temperature distribution measuring device described in Patent Document 2 can measure the two-dimensional temperature distribution in the furnace top space, but cannot measure the surface profile or gas concentration of the burden. Furthermore, the gas analyzer described in Patent Document 3 performs local measurements at the tips of the gas sampling tube and thermocouple inserted into the furnace, and cannot measure the gas concentration distribution and temperature distribution over a wide area in the furnace top space. Furthermore, it cannot measure the deposition state of the burden.

[0006] As described above, the conventional method has a problem in that different measuring devices must be used for different purposes in order to know the state of the furnace.

[0007] The present invention has been made in view of the above circumstances, and aims to accurately measure the surface profile of the burden material, the temperature distribution and the gas concentration distribution in the furnace by a single measuring device when monitoring the furnace conditions. Another aim of the present invention is to provide a method for performing more stable operation based on the measurement results of such a measuring device. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides the following blast furnace condition measuring devices (1) to (7).

[0009] (1) An apparatus for scanning the inside of a blast furnace with a laser beam to measure the surface profile of accumulated burden materials and the temperature distribution and gas concentration distribution in the space above the surface of the burden materials, A blast furnace condition measuring device comprising a light projecting and receiving means for irradiating and receiving the laser light. (2) A blast furnace furnace condition measuring device according to (1), characterized in that the tunable laser light source for measuring the temperature distribution and gas concentration distribution and the laser light source for the distance meter for measuring the surface profile of the charge have different wavelengths. (3) A blast furnace condition measuring device according to (2), characterized in that a combined laser light obtained by combining the wavelength-tunable laser light emitted from the wavelength-tunable laser light source and the distance meter laser light emitted from the distance meter laser light source is propagated through the same optical path. (4) A blast furnace furnace condition measuring device according to (3), characterized in that a position where the light receiving level of the combined laser beam is high is selected, and the distance to that position and the temperature and gas concentration on the axis of the combined laser beam are measured. (5) A blast furnace condition measuring device according to any one of (1) to (3), characterized in that it is arranged at a plurality of locations in the blast furnace and measures a three-dimensional surface profile of the charge material, as well as a three-dimensional distribution of the temperature and gas concentration of the blast furnace. (6) The blast furnace furnace condition measuring device according to (3), characterized in that the scanning by the synthetic laser light is temporarily stopped, measurements are repeated at the stop position, and the obtained data is averaged. (7) The blast furnace furnace condition measuring device according to (4), characterized in that the scanning by the synthetic laser light is temporarily stopped, measurements are repeated at the stop position, and the obtained data is averaged.

[0010] In order to solve the above problems, the present invention provides the following blast furnace operation method (8) or (9).

[0011] (8) A method for operating a blast furnace, characterized in that the blast furnace is operated while adjusting operating conditions based on the surface profile of the charge material and the temperature distribution and gas concentration distribution in the space above the surface of the charge material using the blast furnace furnace condition measuring device described in (1). (9) A method for operating a blast furnace, characterized by using the blast furnace condition measuring device described in (4), selecting a position where the laser light reception level is high, and operating the furnace while adjusting the operating conditions based on the distance to the charge and the temperature and gas concentration on the axis of the laser light. [Effects of the Invention]

[0012] According to the blast furnace furnace condition measuring device of the present invention, the surface profile of the burden material, the temperature distribution and the gas concentration distribution in the space above the surface of the burden material can be measured accurately using a single measuring device.

[0013] Furthermore, according to the blast furnace operating method of the present invention, good blast furnace operation is possible based on the measurement results obtained by the blast furnace furnace condition measuring device. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic overall configuration of a blast furnace condition measuring device according to the present invention, and a block diagram of a laser device. [Figure 2] FIG. 2 is a schematic diagram showing another example of the scanning means in the blast furnace condition measuring device, in accordance with FIG. [Figure 3] FIG. 3 is a cross-sectional view schematically showing a state in which a blast furnace furnace condition measuring device is installed in the vicinity of the top of the blast furnace, taken along the axis of the blast furnace. [Figure 4] FIG. 4 is a schematic diagram showing an example of a planar scanning locus of the combined laser beam. [Figure 5] FIG. 5 is a schematic diagram showing the arrangement of a plurality of blast furnace furnace condition measuring devices, in which FIG. 5(A) is a perspective view seen from outside the blast furnace, and FIG. 5(B) is a DD cross-sectional view of FIG. 5(A). [Figure 6] FIG. 6 is a schematic diagram showing how a position where the received light level of the combined laser beam is high is selected and the distance thereto, the temperature on the axis of the combined laser beam, and the gas concentration are measured. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described in detail below with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and can be implemented with any modifications within the scope of the gist of the present invention.

[0016] [Blast furnace condition measuring device] 1 is a cross-sectional view showing a schematic diagram of the overall configuration of a blast furnace furnace condition measuring device (hereinafter referred to as "measuring device") 1 of the present invention. As shown in the figure, measuring device 1 is installed at an opening 201 of a blast furnace 200, and sends a combined laser beam L, which is a combination of a wavelength-variable laser beam and a distance-measuring laser beam from a laser device 10, to a light-emitting / receiving head 50, and the combined laser beam L from light-emitting / receiving head 50 is used to scan the furnace interior linearly or planarly by a scanning means.

[0017] In the laser device 10, a tunable laser beam is generated from a tunable laser beam source 12 of a laser control unit 11. The tunable laser beam is a laser beam whose wavelength can be continuously varied. For example, a DFB (Distributed Feedback) laser with excellent wavelength resolution can be used as the tunable laser beam source 12, but any laser beam source capable of varying the output wavelength can be used instead of a DFB laser. The tunable wavelength band of the tunable laser beam is a range that includes the absorption wavelength of the furnace gas to be measured, and the laser control unit 11 continuously varies the output wavelength of the tunable laser beam source 12.

[0018] The wavelength-tunable laser light output from the wavelength-tunable laser light source 12 is split into two by a coupler 13, one of which is sent to a multiplexer 14 and output to a light-emitting / receiving head 50 via a half mirror 15. The other is converted into an electric signal by a photodetector 16 as reference light and output to a temperature / gas concentration signal processor 17.

[0019] Furthermore, the laser device 10 generates a distance measurement laser beam. The distance measurement laser beam is pulse-modulated by a signal from a pulse control unit 18, output from a distance measurement laser light source 19, and branched into two beams by a coupler 20. One beam is then sent to a multiplexer 14, where it is multiplexed with a wavelength-tunable laser beam and output to a light-emitting / receiving head 50 via a half mirror 15. The other beam is converted into an electric signal by a photodetector 21 as reference light and output to a distance measurement signal processing unit 22.

[0020] The wavelength of the distance measurement laser light is different from the wavelength range of the wavelength-tunable laser light, so they do not interfere with each other. In addition to the pulse modulation method described above, frequency modulation method or intensity modulation method may also be used.

[0021] In this way, the wavelength-variable laser light and the distance measurement laser light are combined by the combiner 14, propagated through the optical fiber 28 via the half mirror 15, and sent to the light-projecting and receiving head 50. A collimator lens (not shown) is incorporated in the light-projecting and receiving head 50, and the combined laser light L of the wavelength-variable laser light and the distance measurement laser light passes through the inside of the hollow pipe 60 and is sent to the fixed-angle reflecting mirror 70.

[0022] The tip opening 61 of the hollow pipe 60 is sealed with a plug member 62 made of a heat insulating material that transmits laser light, such as quartz glass, to prevent blast furnace gas from flowing out of the blast furnace 200 from the opening 201.

[0023] The fixed angle reflecting mirror 70 is a reflecting mirror that faces the tip opening 61 of the hollow pipe 60 at an angle of 45°, and the combined laser light L reflected by the fixed angle reflecting mirror 70 is sent to the variable angle reflecting mirror 80.

[0024] The angle-variable reflecting mirror 80 is a reflecting mirror in which the tilt angle of the reflecting surface 80a can be varied in the direction indicated by the symbol X in the figure. In this angle-variable reflecting mirror 80, a first link 81a of a link mechanism 81 is fixed to the center of the surface (back surface) opposite the reflecting surface 80a, and a second link 81b is connected to the first link 81a. In addition, a crankshaft 82 is connected to the second link 81b.

[0025] A sliding pipe 65 is fitted onto the outer periphery of the hollow pipe 60, and the hollow pipe 60 and the sliding pipe 65 form a double-pipe structure. A rotating shaft 67 of a rotating cylinder 66 is fitted onto the outer periphery of the sliding pipe 65. A gear 68 is formed on the outer periphery of the rotating shaft 67, and a gear 91 of a motor 90 is engaged with this gear 68. When the motor 90 is driven, the gear 91 rotates, and via the gear 68, the rotating shaft 67 and further the rotating cylinder 66 rotate in the direction indicated by the arrow symbol Y. The lower end of the sliding pipe 65 is rotatably supported by a bearing 64. An encoder 95 is connected to the motor 90, and the amount of rotation of the motor 90, as well as the amount of rotation of the gear 68 and the rotating cylinder 66, are detected.

[0026] A rack gear 100 is formed on the outer peripheral surface of the sliding pipe 65 on the side of the light emitting and receiving head 50. A pinion gear 111 of a motor 110 meshes with this rack gear 100, and by driving the motor 110 in normal and reverse directions, the pinion gear 111 rotates repeatedly in normal and reverse directions, and the sliding pipe 65 moves up and down via the rack gear 100 as shown by arrow H in the figure. An encoder 120 is connected to the motor 110, and detects the amount of rotation of the motor 110 and further the amount of rotation of the pinion gear 111. Furthermore, since the amount of vertical movement of the rack gear 100 changes depending on the amount of rotation of the pinion gear 111, the amount of vertical movement of the sliding pipe 65 can be detected from the amount of rotation of the motor 110.

[0027] Furthermore, the crankshaft 82, which is connected to the second link 81b of the angle-variable reflecting mirror 80, is attached to the outer ring of the bearing 64 of the sliding pipe 65, so when the sliding pipe 65 moves up and down as shown by the arrow H, the crankshaft 82 also moves up and down accordingly. As the crankshaft 82 moves up and down, the angle between the first link 81a and the second link 81b of the link mechanism 81 changes, and the inclination angle of the reflecting surface 80a of the angle-variable reflecting mirror 80 changes.

[0028] Specifically, when the crankshaft 82 moves toward the angle-variable reflecting mirror 80 (downward in the figure), the reflective surface 80a of the angle-variable reflecting mirror 80 tilts to face rightward in the figure via the link mechanism 81, and when the crankshaft 82 moves away from the angle-variable reflecting mirror 80 (upward in the figure), the reflective surface 80a of the angle-variable reflecting mirror 80 tilts to face leftward in the figure via the link mechanism 81. In other words, by lowering and raising the crankshaft 82, the tilt angle of the reflective surface 80a of the angle-variable reflecting mirror 80 can be changed in the direction of the symbol X in the figure.

[0029] As described above, the rotating cylinder 66 rotates in the direction of arrow Y around the axis of the hollow pipe 60 and the sliding pipe 65, so that the combined laser light L can be scanned in a planar manner by rotating the rotating cylinder 66 and moving the sliding pipe 65 up and down in the direction of arrow H.

[0030] Furthermore, by stopping the rotation of the rotary cylinder 66 and only moving the sliding pipe 65 up and down, the combined laser light L can be scanned linearly along the radius.

[0031] The rotating cylinder 66, the fixed angle reflecting mirror 70, the variable angle reflecting mirror 80 and their peripheral components constitute the "scanning means."

[0032] The surface of the rotating cylinder 66 facing the opening 201 of the blast furnace 200 is sealed with a plate 69 made of a heat insulating material that transmits laser light, such as quartz glass, to block the intrusion of high heat from the opening 201 of the blast furnace 200 and dust floating in the blast furnace 200. In addition, in order to prevent dust from adhering to the plate 69 or to remove any adhering dust, a purge gas such as air or an inert gas may be blown from a purge nozzle 75.

[0033] An outer cylinder 77 is provided on the outside of the rotating cylinder 66 so as to surround the rotating shaft 67, and the outer cylinder 77 is attached to the outer peripheral edge of an opening 201 of a blast furnace 200. In addition, in order to ensure airtightness between the rotating cylinder 66 and the outer cylinder 77, a gland packing 78 is interposed in the gap between the rotating cylinder 66 and the rotating shaft 67.

[0034] The composite laser beam L irradiated into the blast furnace 200 through the opening 201 is reflected by the surface (see FIG. 3; reference numeral 300a) of the charge (see FIG. 3; reference numeral 300) accumulated in the furnace and by the furnace wall, and is sent to the half mirror 15 of the laser device 10 via the angle-variable reflecting mirror 80, following the same path as when it was irradiated. Then, the beam is split into two by the splitter 23, one of which is sent to the filter 24 and the other to the filter 25.

[0035] The filter 24 is used to block wavelengths other than that of the tunable laser light, and the signal is converted into an electrical signal by the photodetector 26 and sent to the temperature / gas concentration signal processor 17. The temperature / gas concentration signal processor 17 calculates the temperature and gas concentration at each scanned optical path from the reference light from the coupler 13 and the absorption spectrum of the received tunable laser light.

[0036] The filter 25 is for blocking wavelengths other than the wavelength of the distance measurement laser light, and the signal is converted into an electrical signal by the photodetector 27 and sent to the distance measurement signal processing unit 22. The distance measurement signal processing unit 22 calculates the distance at each scanned position from the difference in propagation time between the reference light from the coupler 20 and the received distance measurement laser light.

[0037] 2, in the above-described "scanning means," a polygon mirror 150 or a galvanometer mirror (not shown) can be used instead of the variable-angle reflecting mirror 80. A rotation shaft 151 of the polygon mirror 150 is attached to the rotary cylinder 66. One end of the polygon mirror 150 is connected to the crankshaft 82 via a link rod 152, and the link rod 152 rotates the polygon mirror 150 in the direction of arrow Z in the figure in conjunction with the up and down movement of the crankshaft 82. As the polygon mirror 150 rotates, the combined laser light L from the fixed-angle reflecting mirror 70 is scanned linearly along the radius.

[0038] 1, the rotation of the motor 110 can be transmitted to a link mechanism 165 via a turntable 160, and the sliding pipe 65 can be moved up and down via the link mechanism 165. In the link mechanism 165, an L-shaped first link 165a is attached to the outer circumferential surface of the sliding pipe 65, and the first link 165a is connected to the turntable 160 by a second link 165b. When the turntable 160 is rotated in the direction of arrow A by the motor 110, the sliding pipe 65 moves up and down via the link mechanism 165.

[0039] The measuring device 1 can be installed near the top of a blast furnace 200, for example, as shown in Fig. 3. Note that reference numeral 250 in the figure denotes a chute for supplying charge material 300 into the furnace, and scanning is performed in accordance with the rotation of the chute 250 so that the light path is not blocked by the chute 250.

[0040] By synchronizing the rotation of the chute 250 with that of the rotary cylinder 66, scanning can be performed in accordance with the rotation of the chute 250.

[0041] As shown in the figure, the combined laser beam L is irradiated into the blast furnace 200 from diagonally above the furnace, and scans linearly in the radial direction of the blast furnace 200. This linear scanning is performed in a planar manner by rotating the rotary cylinder 66 while tilting the angle-variable reflecting mirror 80. This planar scanning exhibits a "petal-shaped" scanning trajectory, as shown in FIG. 4, for example. That is, by repeating unit scans in the circumferential direction, each of which is an upwardly convex arc-shaped scan followed by a downwardly convex arc-shaped scan, the overall "petal-shaped" shape is exhibited.

[0042] Then, the distance to point a is measured from the propagation time of the distance-measuring laser light of the combined laser light La that is incident on point a on the surface 300a of the charge material 300 and reflected and returned at point a, and the three-dimensional orthogonal coordinates (x, y, z) at point a are obtained from the tilt angle of the angle-variable reflecting mirror 80 and the rotation angle of the rotating cylinder 66 at that time. The same measurement is performed planarly, and a three-dimensional profile of the surface 300a of the charge material 300 can be obtained by polygon processing or the like. At the same time, the temperature and gas concentration on the optical path of the combined laser light La are measured from the absorption spectrum of the wavelength-variable laser light of the combined laser light La that is reflected and returned at point a.

[0043] In this way, according to the measuring device 1 of the present invention, the three-dimensional profile of the surface 300a of the charge material 300, and the temperature distribution and gas concentration distribution on the surface of the charge material 300 can be measured simultaneously by making the combined laser light L of the distance meter laser light and the wavelength variable laser light, and irradiating it toward the furnace along the same optical axis.

[0044] It should be noted that numerous dust particles are floating inside the blast furnace 200, and the influence of the dust particles causes the intensity of the received combined laser light L to change randomly. Therefore, the tilting of the angle-variable reflecting mirror 80 and the rotation of the rotating cylinder 66 are stopped, and the same location is continuously measured multiple times and an averaging process is performed, thereby eliminating the influence of the dust particles.

[0045] It is also possible to use a plurality of measuring devices 1. For example, as shown in Fig. 5(A), three measuring devices 1A to 1C are installed at equal intervals in the circumferential direction near the top of a blast furnace 200. Then, the three measuring devices 1A to 1C are scanned in sequence.

[0046] Figure 5(B) is a DD cross-sectional view of Figure 5(A), where the scan areas of the measuring devices 1A to 1C overlap, and by combining them, it is possible to complement the range that could not be scanned by a single measuring device. This makes it possible to obtain a 3D profile over the entire surface of the charge material 300. Furthermore, by using a CT image reconstruction method based on the absorption spectrum of the tunable laser light in each optical path of the measuring devices 1A to 1C, it is possible to obtain a 3D cross-sectional image of the temperature distribution and gas concentration distribution in the space above the surface of the charge material 300.

[0047] Furthermore, as shown in FIG. 6, by continuously measuring point c on the surface 300a of the charge 300 where no dust is floating, the temperature and gas concentration on the optical path of the combined laser light Lc can be measured with high accuracy.

[0048] For example, the combined laser beam Lc reflected at point c where no dust is floating and returned has a higher light receiving level than the combined laser beam Lb reflected at point b where dust is floating and returned. In other words, the state of dust can be determined by scanning the surface 300a of the charge 300 and obtaining the light receiving level distribution of the combined laser beam L.

[0049] Furthermore, by selecting a measurement point from the distribution of light reception levels where the light reception level is high and the distance from the measuring device 1 is short, pointing the angle-variable reflecting mirror 80 at that position, and measuring the distance to point c and the temperature and gas concentration on the axis of the combined laser light Lc, it becomes possible to perform highly sensitive measurements that minimize not only the effects of dust but also attenuation due to distance.

[0050] [Blast furnace operation method] In the present invention, the above-described measuring devices 1, 1A to 1C are used to appropriately control the supply of charge materials and the temperature and gas based on the surface profile of the charge materials deposited in the furnace and the temperature distribution and gas concentration distribution in the space above the surface of the charge materials, thereby enabling stable operation of the blast furnace 200. [Explanation of symbols]

[0051] 1, 1A~1C measuring device 10 Laser device 11 Laser control unit 12 Tunable laser light source 14 Multiplexer 15 Half Mirror 16 Photodetector 17 Temperature and gas concentration signal processing section 18 Pulse control section 19 Laser light source for distance measurement 21 Photodetector 22 Distance measurement signal processing section 26, 27 Photodetector 50 Light emitting and receiving head 60 Hollow Pipe 65 Sliding Pipe 66 Rotating Cylinder 70 Fixed angle reflector 80 Variable angle reflecting mirror 81, 165 Link mechanism 90, 110 motor 95, 120 encoder 100 Rack Gear 111 Pinion gear 160 Turntable 200 blast furnace 201 Aperture 250 shots 300 Charge

Claims

1. An apparatus for scanning the inside of a blast furnace with a laser beam to measure the surface profile of accumulated burden material and the temperature distribution and gas concentration distribution in the space above the surface of the burden material, A blast furnace condition measuring device comprising a light projecting and receiving means for irradiating and receiving the laser light.

2. 2. The blast furnace furnace condition measuring device according to claim 1, wherein the tunable laser light source for measuring the temperature distribution and the gas concentration distribution and the laser light source for the distance meter for measuring the surface profile of the burden have different wavelengths.

3. 3. The blast furnace condition measuring device according to claim 2, wherein a combined laser light obtained by combining the wavelength-tunable laser light emitted from the wavelength-tunable laser light source and the distance meter laser light emitted from the distance meter laser light source is propagated through the same optical path.

4. 4. The blast furnace condition measuring device according to claim 3, wherein a position where the light receiving level of the combined laser beam is high is selected, and the distance to that position and the temperature and gas concentration on the axis of the combined laser beam are measured.

5. The blast furnace furnace condition measuring device according to any one of claims 1 to 3, characterized in that it is arranged at a plurality of locations in the blast furnace and measures a three-dimensional surface profile of the charge, as well as a three-dimensional distribution of temperature and gas concentration in the blast furnace.

6. 4. The blast furnace condition measuring device according to claim 3, wherein the scanning by the combined laser light is temporarily stopped, and measurements are repeatedly performed at the stop position, and the obtained data is averaged.

7. 5. The blast furnace furnace condition measuring device according to claim 4, wherein the scanning by the combined laser light is temporarily stopped, and measurements are repeatedly performed at the stop position, and the obtained data is averaged.

8. A blast furnace operating method, characterized in that the blast furnace is operated while adjusting operating conditions based on the surface profile of the charge material and the temperature distribution and gas concentration distribution in the space above the surface of the charge material, using the blast furnace furnace condition measuring device according to claim 1.

9. A method for operating a blast furnace, comprising using the blast furnace condition measuring device according to claim 4, selecting a position where the light receiving level of the laser light is high, and adjusting operating conditions based on the distance to the charge and the temperature and gas concentration on the axis of the laser light.

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