Refractory state visualization method, refractory repair method, and refractory state visualization device

Abstract

The input section 101 inputs elasticity 21 to a furnace wall 11 having refractory bricks 16 as refractory materials. The reception unit (102) receives a reflected wave (22) of the elastic wave (21). The control unit (103) obtains the frequency characteristics of the reflected wave (22), obtains the distance characteristics from the frequency characteristics, and generates a map representing the likelihood of the reflection position in the refractory brick (16) on the basis of the distance characteristics. In this way, the state of the refractory brick 16 is visualized.

Description

Technical Field

[0001] The present invention relates to a method for visualizing the state of a refractory, a method for repairing a refractory, and a device for visualizing the state of a refractory. Background Art

[0002] The furnace wall of an industrial furnace such as a blast furnace generally has iron sheets, amorphous refractory materials, and refractory bricks (shaped refractory materials) in this order from the outside to the inside.

[0003] The refractory bricks, which are the innermost refractory materials, are worn from the furnace core side and sometimes cracked inside. In particular, the refractory bricks at the bottom of the blast furnace are always exposed to molten iron even when the air is stopped, so they wear more severely. Wear and cracking of refractory bricks will shorten the life of the furnace body.

[0004] Therefore, it is important to understand the state of refractory bricks in terms of furnace maintenance and management, and methods for measuring the remaining thickness of refractory bricks have been proposed in the past (Patent Documents 1 and 2).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 62-297710

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 8-219751 Summary of the invention

[0009] Problems to be solved by the invention

[0010] The methods described in Patent Documents 1 and 2 measure only the remaining thickness of refractory bricks.

[0011] In terms of furnace maintenance and management, it is preferable to be able to visually grasp the state of the refractory bricks, including not only the remaining thickness of the refractory bricks but also cracks generated inside the refractory bricks.

[0012] The present invention has been made in view of the above points, and an object of the present invention is to visualize the state of refractory materials such as refractory bricks.

[0013] Means for solving problems

[0014] After diligent research, the present inventors found that the above-mentioned object can be achieved by adopting the following structure, and completed the present invention.

[0015] That is, the present invention provides the following [1] to [4].

[0016] [1] A method for visualizing the state of a refractory material, comprising: a step of inputting an elastic wave into a furnace wall having refractory materials; a step of receiving a reflected wave of the elastic wave; a step of determining a frequency characteristic of the reflected wave; a step of determining a distance characteristic based on the frequency characteristic; and a step of generating a mapping diagram representing the likelihood of a reflection position in the refractory material based on the distance characteristic.

[0017] [2] The method for visualizing the state of a refractory material according to [1] above, wherein:

[0018] The distance characteristic includes a plurality of distance characteristics, and the map is generated by synthesizing maps created according to the plurality of distance characteristics.

[0019] [3] A method for repairing a refractory, wherein the refractory is repaired based on a map generated using the method for visualizing the state of a refractory according to [1] or [2] above.

[0020] [4] A device for visualizing the state of refractory materials, comprising: an input unit for inputting elastic waves into a furnace wall having refractory materials; a receiving unit for receiving reflected waves of the elastic waves; and a control unit for obtaining a frequency characteristic of the reflected waves, obtaining a distance characteristic based on the frequency characteristic, and generating a mapping diagram representing the likelihood of a reflection position in the refractory materials based on the distance characteristic.

[0021] Effects of the Invention

[0022] According to the present invention, the state of refractory materials such as refractory bricks can be visualized. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a cross-sectional view showing a portion of a furnace wall when a CS structure blast furnace is viewed from above.

[0024] Figure 2 It is a schematic diagram showing the state visualization device together with the furnace wall.

[0025] Figure 3 This is a perspective view showing a furnace wall in a state where a receiving portion is mounted on an iron sheet.

[0026] Figure 4 is a schematic diagram of the amplitude spectrum.

[0027] Figure 5 is a schematic diagram of the distance characteristic graph.

[0028] Figure 6 This is a schematic diagram of a map based on the reception result of the receiving unit at point C1.

[0029] Figure 7 This is a schematic diagram of a map based on the reception result of the receiving unit at point A1.

[0030] Figure 8 is a schematic diagram of the synthetic map.

[0031] Fig. 9 is a schematic diagram representing a voxel cloud.

[0032] Fig.10 is a schematic diagram representing other voxel clouds.

[0033] Fig.11 This is a flowchart showing an example of the flow of processing executed by the control unit.

[0034] Fig.12 This is a flowchart showing another example of the flow of processing executed by the control unit.

[0035] Fig.13 This is a functional block diagram of a status visualization device.

[0036] Fig.14 This is a perspective view showing a furnace wall in a state where a receiving portion is mounted on an iron sheet.

[0037] Fig.15 This is a schematic diagram of the distance characteristics calculated by the distance characteristics calculation unit.

[0038] Fig.16 It is a perspective view showing a furnace wall in a state where M receiving parts are mounted on an iron sheet.

[0039] Fig.17 It is a schematic diagram showing a display unit that displays a heat map.

[0040] Fig.18 This is a flowchart showing an example of the flow of processing in the state visualization device. DETAILED DESCRIPTION

[0041] [Status Visualization Device]

[0042] Hereinafter, a refractory state visualization device (also simply referred to as a "state visualization device") will be described. The following description also serves as a description of a refractory state visualization method and a refractory repair method.

[0043] First, the furnace wall of the blast furnace will be described.

[0044] Conventionally, the furnace wall of a blast furnace has a three-layer structure having iron sheets, amorphous refractory materials, and refractory bricks (shaped refractory materials) in this order, but currently, blast furnaces are basically CS (Cooling Stave) structure blast furnaces.

[0045] Figure 1 1 is a cross-sectional view showing a portion of the furnace wall 11 when the CS structure blast furnace is viewed from above. Figure 1It is a cross-sectional view of the furnace wall 11 constituting the furnace bottom.

[0046] like Figure 1 As shown in FIG. 1 , the furnace wall 11 of the CS structure blast furnace (hereinafter, also referred to as “blast furnace”) is a five-layer structure. That is, the furnace wall 11 is a five-layer structure from the outside to the inside (from Figure 1 From the left side to the right side in the figure, there are iron sheets 12, unshaped refractory materials 13, copper plates 14, unshaped refractory materials 15 and refractory bricks 16 (shaped refractory materials) in this order.

[0047] As the monolithic refractory 13 and the monolithic refractory 15, a stamping material is preferably used.

[0048] It should be noted that, as amorphous refractory, there are ramming material and castable refractory, and the composition and construction method of the two are different from each other. Specifically, the main component of ramming material is carbon material, which is solidified by ramming with a ramming hammer, while the main component of castable refractory is high alumina cement, which is solidified by drying.

[0049] Conventionally known blast furnace bricks such as high alumina bricks and silicon carbide bricks are used as the refractory bricks 16. The refractory bricks 16 are exposed to molten iron (not shown) and wear away.

[0050] A plurality of holes 17 are formed in the copper plate 14. Water flows through the holes 17 from the upper side to the lower side of the blast furnace, thereby cooling the blast furnace.

[0051] Furthermore, conventionally, the temperature is monitored using a thermocouple, and the remaining thickness of the refractory brick is estimated by heat transfer calculation based on the temperature.

[0052] However, in a CS structure blast furnace, since the above-mentioned cooling structure provides excellent thermal insulation, it is sometimes difficult to estimate the remaining thickness of refractory bricks by heat transfer calculation.

[0053] Therefore, it is preferable to use the state visualization device 1 described below. Thereby, the state of the refractory bricks including the remaining thickness can be grasped.

[0054] Figure 2 1 is a schematic diagram showing the state visualization device 1 together with the furnace wall 11 .

[0055] However, in Figure 2 In the figure, among the members constituting the furnace wall 11, illustration of members other than the iron sheet 12 and the refractory bricks 16 (the monolithic refractory material 13 and the like) is omitted.

[0056] The state visualization device 1 includes at least an input unit 101, a receiving unit 102, and a control unit 103. For example, the input unit 101 is a hammer, the receiving unit 102 is an accelerometer, and the control unit 103 is composed of an amplifier, an oscilloscope, and a PC (personal computer).

[0057] Figure 3 1 is a perspective view showing the furnace wall 11 in a state where the receiving portion 102 is mounted on the iron sheet 12. Figure 3 In the figure, the members constituting the furnace wall 11 other than the iron sheet 12 and the refractory bricks 16 (the monolithic refractory material 13, etc.) are also omitted. Figure 3 The X-axis direction, the Y-axis direction, and the Z-axis direction are also shown. The Z-axis direction is the thickness direction of the refractory brick 16.

[0058] The receiving unit 102 as an accelerometer is arranged on the surface of the iron sheet 12, as an example. Figure 3 As shown, four points (point A1, point A3, point C1, and point C3) are arranged on the surface of the iron sheet 12 so as to form a rectangle.

[0059] Refer again Figure 2 .

[0060] like Figure 2 As shown, the input unit 101 as a striking hammer strikes the surface of the iron sheet 12 (for example, each point where the receiving unit 102 is arranged) to excite the furnace wall 11 including the refractory bricks 16. As a result, the elastic wave 21 is input to the furnace wall 11. Hereinafter, for convenience, the point on the surface of the iron sheet 12 struck by the input unit 101 is sometimes referred to as a "strike point".

[0061] The elastic wave 21 propagates inside the furnace wall 11, is reflected at the terminal 18 of the refractory brick 16, and becomes a reflected wave 22. The receiving unit 102 as an accelerometer receives (detects) the reflected wave 22 as an acceleration signal. Hereinafter, for convenience, a point on the surface of the iron sheet 12 where the receiving unit 102 for receiving the reflected wave 22 is arranged is sometimes referred to as a "measurement point".

[0062] First, based on Figures 4 to 6 The flow of processing executed by the control unit 103 when a map (to be described later) is created when the measurement point is the point C1 and the marking point is the point A1 will be described.

[0063] The control unit 103 analyzes the acceleration signal received by the receiving unit 102 and obtains the frequency characteristics. In other words, the control unit 103 converts the acceleration signal into an amplitude spectrum (frequency spectrum) and obtains the resonance frequency (peak frequency).

[0064] It should be noted that before this, the relationship between the resonance frequency and the thickness of the refractory brick 16 (the reflection position of the elastic wave 21) is obtained in advance through simulation (for example, elastic wave propagation simulation) etc. (hereinafter also referred to as "conversion model"). The conversion model is pre-stored in the control unit 103 or an external storage device (not shown).

[0065] The control unit 103 inputs the resonance frequency obtained from the acceleration signal into the conversion model to obtain a distance characteristic indicating the relationship between the amplitude and the distance from the measurement position (such as the point C1 ).

[0066] Furthermore, when cracks 19 are generated in the refractory bricks 16, the elastic waves 21 are reflected not only at the terminals 18 but also at the cracks 19. Figure 4 Schematic diagram of an amplitude spectrum obtained from the reflected wave 22 (acceleration signal) in this case is shown in FIG.

[0067] Figure 4 This is a schematic diagram of the amplitude spectrum (measurement point: point C1, marking point: point A1), where the vertical axis represents the amplitude (intensity) and the horizontal axis represents the frequency. Figure 4 In the amplitude spectrum of , the peak on the low-frequency side is a peak caused by reflection at the terminal 18 , and the peak on the high-frequency side is a peak caused by reflection at the crack 19 .

[0068] By Figure 4 The amplitude spectrum of is applied to the above conversion model, thereby converting it into a one-dimensional distance characteristic graph (hereinafter also referred to as "distance characteristic graph") representing the relationship between the amplitude and the distance from the measurement point (the distance in the Z-axis direction). Figure 5 Schematic diagram showing a distance characteristic graph.

[0069] Figure 5 This is a schematic diagram of a distance characteristic graph (measurement point: point C1, punching point: point A1), in which the vertical axis represents the amplitude (intensity) and the horizontal axis represents the distance from the measurement point.

[0070] It should be noted that the number of times (number of times of striking) the furnace wall 11 using the input unit 101 can be once for each measuring point, or multiple times (for example, 3 times) for each measuring point. In the case of multiple times, it is preferred that the control unit 103 obtains the distance characteristic diagram according to the acceleration signal each time.

[0071] Next, the control unit 103 performs Figure 5 The distance characteristic graph depicts the mapping graph.

[0072] As the map, a two-dimensional or three-dimensional map is preferred.

[0073] In this embodiment, as an example of a map ( Figure 6 to Figure 8 ), which stands for heat map. A heat map is a type of visualization chart that expresses each value of two-dimensional numerical data (matrix data) as color or shade.

[0074] As described later, the map (heat map) indicates the likelihood of the reflection position in the refractory brick 16, and the following two types (a) and (b) are exemplified.

[0075] (a) Map with one measurement point: For example, Figure 6-7 The mapping diagram shown is a distance characteristic diagram (such as Figure 5 ) is a graph formed by arranging the points in a circle with the measuring point as the centre, or a graph formed by overlapping the points in a sphere with the measuring point as the centre.

[0076] (b) A map with multiple measurement points: for example, Figure 8 or Fig.17 The map shown is a composite of a plurality of the maps of (a) above while maintaining the relationship between the distance and the coordinates (positional relationship) of the measurement points. Since there are a plurality of measurement points, the accuracy of the likelihood is more excellent.

[0077] Figure 6 to Figure 8 The heat map shown has the distance from the measurement point as the vertical axis and the horizontal axis, and depicts the amplitude (intensity) with light and dark. The amplitude (intensity) can also be expressed with hue.

[0078] The heat map may be a three-dimensional heat map or a two-dimensional heat map of any cross section selected by the user of the state visualization device 1A.

[0079] It should be noted that when drawing the map, it is preferable that the vertical axis of each distance characteristic graph is normalized. Normalization can be performed using the maximum value of the vertical axis or the sum of the absolute values ​​of the vertical axis values.

[0080] Figure 6 is a schematic diagram of a map of the reception result of the receiving unit 102 based on point C1 (measurement point: point C1, marking point: point A1), which shows that Figure 3 The XZ plane of point C1 and point A1 of the furnace wall 11 is shown.

[0081] Specifically, the control unit 103 sets the origin 0 to point C1 and draws the Figure 5 In this way, a mapping diagram ( Figure 6 ).

[0082] use Fig. 9 Description Control unit 103 based on Figure 5 The distance characteristic graph (measurement point: point C1, marking point: point A1) is created Figure 6 Processing of the case of a mapping diagram.

[0083] First, the control unit 103 divides the refractory bricks 16 into a grid shape. Here, each grid is called a "voxel", and a collection of voxels is called a "voxel cloud". The size of a voxel (e.g., the length of one side) is not particularly limited. For example, the length of one side of a voxel in a grid shape (cube shape) can be 1 mm.

[0084] Fig. 9 is a schematic diagram showing voxel cloud A02. Fig. 9 2 also shows the receiving portion 102 disposed at a point C1 on the surface of the iron sheet 12 .

[0085] The control unit 103 calculates the distance d between a voxel A01 included in the voxel cloud A02 and the point C1. Next, the control unit 103 refers to the distance characteristic table ( Figure 5 ), a process is performed on the voxel A01 to reflect the amplitude (intensity) v corresponding to the distance d as a value. This process is performed on all voxels of the voxel cloud A02. Thus, the same amplitude (intensity) value is set for voxels that are equidistant from the point C1, and the same amplitude (intensity) is set in a concentric sphere centered on the point C1.

[0086] The control unit 103 extracts only the voxels on the XZ plane passing through the points C1 and A1 from among the voxels included in the voxel cloud A02. Thus, a two-dimensional heat map ( Figure 6 ).

[0087] Figure 6 The intensity (shade, etc.) in the mapping diagram represents the likelihood of the reflection position of the elastic wave 21 in the refractory brick 16 (including the position of the terminal 18). Figure 6 The map diagram shows a rough state of the remaining refractory bricks 16 .

[0088] exist Figure 6 In the mapping diagram, for example, the weaker the intensity (vertical axis), the lighter the image is drawn, and the stronger the intensity (vertical axis), the darker the image is drawn. The difference in intensity may also be expressed by color.

[0089] exist Figure 6 For the sake of convenience, only Figure 5 The two peaks in the graph correspond to the two black bands. Figure 6 The two black bands in represent positions where the likelihood of the reflection position is relatively high. That is, the possibility of including the crack 19 or the terminal 18 of the refractory brick 16 is high.

[0090] Whether the black band is the crack 19 or the terminal 18 is determined by the distance from the point C1 used as the measurement point. For example, a black band closer to the point C1 is more likely to include the crack 19, while a black band farther from the point C1 is more likely to include the terminal 18.

[0091] Specifically, in Figure 6 In the middle, the bold line indicates Figure 5 The peak on the left side of the graph (a peak that is more likely to include the position of the crack 19) is represented by a thicker line (very thick line) than the peak on the right side (a peak that is more likely to include the position of the terminal 18).

[0092] Next, when the measuring point is set to point C1 and the marking points are all points other than point A1, the control unit 103 executes the same operation as based on Figures 4 to 6 The same processing as described above, Figure 6 Multiple 2D heatmaps are obtained independently.

[0093] For example, first, a two-dimensional heat map is obtained when the measured point is point C1 and the marked point is point C3. Next, a two-dimensional heat map is obtained when the measured point is point C1 and the marked point is point A3. Further, a two-dimensional heat map is obtained when the measured point is point C1 and the marked points are points other than points A1, C3, and A3.

[0094] Furthermore, the control unit 103 also draws a map based on the reception results of the reception unit 102 arranged at the remaining points (point A1, etc.).

[0095] For example, the control unit 103 first performs the same operation as based on the case where the measured point is point A1 and the marked point is point C1. Figures 4 to 6 The same processing as described above is performed to obtain a two-dimensional heat map ( Figure 7 ).

[0096] Figure 7 is a schematic diagram of a mapping diagram based on the reception result of the receiving unit 102 at point A1 (measurement point: point A1, marking point: point C1), which shows that Figure 3 The XZ plane of point C1 and point A1 of the furnace wall 11 is shown.

[0097] exist Figure 7 In, also with Figure 6 Similarly, for the sake of convenience, a position in the distance characteristic graph that is highly likely to include the position of the crack 19 is indicated by a bold line, and a peak that is highly likely to include the position of the terminal 18 is indicated by an extremely bold line.

[0098] use Fig.10 The control unit 103 generates a distance characteristic chart (measurement point: point A1, marking point: point C1) based on the distance characteristic chart (not shown). Figure 7 Processing of the case of a mapping diagram.

[0099] First, the control unit 103 divides the refractory bricks 16 into a grid shape.

[0100] Fig.10 is the same as voxel cloud A02 ( Fig. 9 ) is a schematic diagram of another independent voxel cloud B02. Fig.10 The receiving unit 102 disposed at point A1 is also shown in FIG.

[0101] The control unit 103 calculates the distance d between the voxel B01 included in the voxel cloud B02 and the point A1. Next, the control unit 103 refers to the distance characteristic chart (measurement point: point A1, marking point: point C1) not shown in the figure, and performs a process of reflecting the amplitude (intensity) v corresponding to the distance d as a value for the voxel B01. This process is performed on all voxels in the voxel cloud B02. As a result, the same amplitude (intensity) value is set for voxels that are equidistant from the point A1, and the same amplitude (intensity) is set in a concentric sphere centered on the point A1.

[0102] The control unit 103 extracts only the voxels on the XZ plane passing through the points C1 and A1 from among the voxels included in the voxel cloud B02. Thus, a two-dimensional heat map ( Figure 7 ).

[0103] Next, when the measuring point is set to point A1 and the marking points are all points other than point C1, the control unit 103 performs the same processing as Figure 7 Independently obtain a 2D heat map.

[0104] For example, first, a two-dimensional heat map is obtained when the measured point is point A1 and the marked point is point C3. Next, a two-dimensional heat map is obtained when the measured point is point A1 and the marked point is point A3. Further, a two-dimensional heat map is obtained when the measured point is point A1 and the marked points are points other than point A1, point C3, and point A3.

[0105] Furthermore, the control unit 103 also performs the same operation as that described above for a case where the measurement points are other than the point C1 and the point A1 (for example, a case where the measurement points are the point C3 and the point A3). Figure 6 and Figure 7 Independently obtain a 2D heat map.

[0106] Thereafter, the control unit 103 synthesizes the drawn maps to generate a synthesized map.

[0107] Figure 8 is a schematic diagram of the synthetic map. Specifically, Figure 6 and Figure 7 The synthesized map (synthesized map) represents the Figure 3 The XZ plane of point C1 and point A1 of the furnace wall 11 is shown.

[0108] exist Figure 8 The two thick lines represent Figure 6 and Figure 7 middle position.

[0109] use Fig. 9 and Fig.10 Description Control unit 103 based on Figure 6 Mapping diagram (measurement point: point C1, marking point: point A1) and Figure 7 The mapping diagram (measurement point: point A1, marking point: point C1) is created Figure 8 Processing in the case of a synthetic map.

[0110] It should be noted that, even when maps having the same measurement points but different dot patterns are combined, the same processing as the processing described below may be performed.

[0111] First, the control unit 103 refers to Fig. 9 Voxel cloud A02 (measurement point: point C1, marking point: point A1) and Fig.10 Even if they are different voxel clouds, voxels with the same coordinates represent the same position of the refractory 16 .

[0112] The control unit 103 sets the voxel cloud A02 ( Fig. 9 ) and voxel cloud B02( Fig.10 ) are added together with the amplitude (intensity) values ​​set for the voxels with the same coordinates (for example, voxel A01 and voxel B01) and calculated as a new intensity value (synthesized value).

[0113] The calculated composite value is compared with voxel cloud A02 ( Fig. 9 ) and voxel cloud B02( Fig.10 ) A voxel C01 (not shown) having the same coordinates as voxel A01 and voxel B01 in an independent voxel cloud C02 (not shown) is set.

[0114] Then, the control unit 103 extracts only the voxels on the XZ plane passing through the point C1 and the point A1 from the new voxel cloud C02, among the voxels for which the synthesis value is set. Thus, a two-dimensional heat map ( Figure 8 ).

[0115] The control unit 103 is still Figure 3 Such a map is similarly generated in the YZ plane through which the points A1 and A3 of the furnace wall 11 shown in the figure pass.

[0116] Next, a three-dimensional mapping map is obtained based on the mapping map of the XZ plane and the mapping map of the YZ plane.

[0117] In addition, the control unit 103 can obtain a new voxel cloud C02 formed by setting a synthesis value in each voxel as a three-dimensional map. In the three-dimensional map, the magnitude of the intensity (synthesized value) is also expressed by the difference in color or lightness and darkness.

[0118] The control unit 103 displays the obtained map (heat map in the present embodiment) on, for example, a display unit 104 described later. In this way, the state of the refractory bricks 16 can be visualized.

[0119] The obtained map includes not only the position of the terminal 18 (ie, the remaining thickness of the refractory brick 16) but also information on the position of the crack 19, thereby enabling the operator to visually grasp the state of the refractory brick 16 during the operation of the blast furnace.

[0120] The operator can repair the refractory bricks 16 based on the obtained map.

[0121] That is, by referring to the map that visualizes the state of the refractory bricks 16 , it is possible to determine the repair timing of the refractory bricks 16 and repair the refractory bricks 16 .

[0122] For example, when the occurrence of the cracks 19 in the refractory bricks 16 is confirmed by referring to the map, the refractory bricks 16 can be repaired before a predetermined repair time.

[0123] It should be noted that the number of receiving units 102 is not limited to four, and may be less or more than four. For example, even if the number of receiving units 102 is one, as described above, a mapping diagram (for example, referring to Figure 6 and Figure 7 ).

[0124] Of course, from the viewpoint of grasping the state of the refractory bricks 16 with higher accuracy, the number of the receiving parts 102 is preferably two or more.

[0125] In this embodiment, the processing performed by the control unit 103 can be summarized as follows: Fig.11 or Fig.12 Description of the process.

[0126] It should be noted that the processing described below is performed when there are multiple markings at each measurement point, and each measurement point may be one marking point.

[0127] Fig.11 This is a flowchart showing an example of the flow of processing executed by the control unit 103 .

[0128] First, the receiving unit 102 disposed at each measuring point (eg, point C1, point A1, point C3, point A3) receives the reflected wave 22 as an acceleration signal (step S11). At this time, the reflected wave 22 from each marking point is received at each measuring point.

[0129] Next, the control unit 103 converts the reflected wave 22 into an amplitude spectrum (see Figure 4 ) (step S12), convert the amplitude spectrum into a distance characteristic diagram (refer to Figure 5 ) (step S13), and a mapping diagram is prepared based on the distance characteristic diagram (refer to Figure 6 or Figure 7 )(Step S14).

[0130] If all the dot maps have not been created for all the measuring points, the above process is repeated (step S15 is No). If all the dot maps have been created for all the measuring points (step S15 is Yes), the control unit 103 synthesizes the created maps to create a synthesized map (see Figure 8 ) (Step S16). Then, the control unit 103 displays the created synthetic map on the display unit 104 described later (Step S17).

[0131] Fig.12 2 is a flowchart showing another example of the flow of processing executed by the control unit 103. First, the receiving unit 102 disposed at each measuring point receives the reflected wave 22 as an acceleration signal (step S21). At this time, the reflected wave 22 from each marking point is received at each measuring point.

[0132] If the reflected waves 22 from all the marking points are received at all the measuring points (step S22: Yes), the control unit 103 converts each reflected wave 22 into an amplitude spectrum (refer to Figure 4 )(Step S23).

[0133] If all reflected waves 22 have been converted into amplitude spectra (step S24: Yes), the control unit 103 converts each amplitude spectrum into a distance characteristic graph (refer to Figure 5 )(Step S25).

[0134] If all the amplitude spectra have been converted into distance characteristic graphs (step S26: Yes), the control unit 103 creates a map based on each distance characteristic graph (see Figure 6 or Figure 7 )(Step S27).

[0135] If maps are created for all distance characteristic tables (Yes in step S28), the control unit 103 synthesizes the created maps to create a synthesized map (see Figure 8 ) (Step S29). Then, the control unit 103 displays the created synthetic map on the display unit 104 described later (Step S30).

[0136] In the above, the case where the state visualization device is applied to a CS structure blast furnace is described as an example.

[0137] However, furnaces (industrial furnaces) to which the status visualization device can be applied are not limited to these. For example, furnaces having furnace walls with iron sheets and refractory materials (refractory bricks) can be listed. Specific examples include blast furnaces other than CS-structured blast furnaces (three-layered blast furnaces), electric furnaces, converters, ladles (RH furnaces, etc.), torpedo cars, gasification and melting furnaces, etc.

[0138] [Other embodiments (Embodiment A)]

[0139] Next, use Figure 13 to Figure 18 A state visualization device 1A according to another embodiment (referred to as “embodiment A”) will be described.

[0140] <Structure of Status Visualization Device 1A>

[0141] Fig.13 2 is a functional block diagram of the state visualization device 1A.

[0142] like Fig.13 As shown, the state visualization device 1A includes an input unit 101 , a receiving unit 102 , a control unit 103 , and a display unit 104 .

[0143] 《Input 101》

[0144] The input unit 101 is composed of a striking hammer, a vibrator, and the like.

[0145] When the input unit 101 is constituted by a hammer, for example, a hammer having a frequency characteristic capable of measuring the maximum value of a hypothetical resonance frequency is used. The hypothetical value of the resonance frequency can be calculated by simulation.

[0146] 《Receiving Department 102》

[0147] The receiving unit 102 is constituted by, for example, an accelerometer.

[0148] When the receiving unit 102 is composed of an accelerometer, it is preferable to use an accelerometer that can detect the iron sheet 12 (see Figure 1 ) is an accelerometer that measures the acceleration in the normal direction of the axis.

[0149] 《Control Department 103》

[0150] The control unit 103 controls the entire state visualization device 1A.

[0151] The control unit 103 is composed of, for example, one or more processors.

[0152] The control unit 103 may be constituted by a logic circuit (hardware) formed on an integrated circuit (IC chip) or the like.

[0153] The control unit 103 can be configured by software using a CPU (Central Processing Unit).

[0154] The control unit 103 may be composed of a FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or the like.

[0155] The control unit 103 includes a frequency analyzing unit 201, a distance characteristic calculating unit 202, a storage unit 203, and a map generating unit 204. Each of these units may include an independent housing.

[0156] The frequency analysis unit 201 is constituted by, for example, an FFT analyzer. The distance characteristic calculation unit 202, the storage unit 203, and the map generation unit 204 are constituted by, for example, a personal computer (PC).

[0157] The control unit 103 may be provided with a data bus for exchanging data between the above-mentioned units.

[0158] Some of the components constituting the control unit 103 may be provided in another terminal (not shown).

[0159] (Frequency Analysis Unit 201)

[0160] The frequency analysis unit 201 receives the reflected wave received by the receiving unit 102 , performs frequency analysis, and calculates the frequency characteristics.

[0161] As the frequency characteristic of the output, for example, an amplitude spectrum is used, but the present invention is not limited thereto. For example, a frequency response function calculated from the elastic wave input from the input unit 101 and the reflected wave received by the receiving unit 102 may be used.

[0162] As a method of frequency analysis, for example, discrete Fourier transform (DFT) and fast Fourier transform (FFT) that executes DFT at high speed can be cited, but the method is not limited to these and analysis by wavelet transform may also be performed.

[0163] The frequency analysis unit 201 can directly perform frequency analysis on the reflected wave received from the receiving unit 102 to obtain an amplitude spectrum. In addition, the frequency analysis unit 201 can use a bandpass filter to perform frequency analysis only on a signal in a specific frequency band to obtain an amplitude spectrum. Furthermore, the frequency analysis unit 201 can perform frequency analysis on a signal cut out from the received reflected wave using a window function to obtain an amplitude spectrum.

[0164] ((Calculation of frequency characteristics by frequency analysis unit 201))

[0165] As a method for the frequency analysis unit 201 to calculate the frequency characteristics, a method using discrete Fourier transform will be described.

[0166] The sampling number of the acceleration signal measured by the receiving unit 102 at time t is set to n, and the signal obtained by sampling the acceleration signal is set to a(n). At this time, the discrete Fourier transform A(k) of a(n) can be calculated by the following formula (1).

[0167] [Mathematical formula 1]

[0168]

[0169] Here, k is a frequency sampling number (k=0, 1, . . . , N-1), and N is a gate length of a sampled signal a(n) to be subjected to discrete Fourier transform.

[0170] The lower limit of the gate length N can be used to observe the maximum frequency f max , calculated based on the reciprocating time T of the elastic wave at the maximum thickness of the refractory brick 16 and the reciprocating number m of the elastic wave used in the frequency analysis. When the sampling interval of the acceleration signal is set to Δt, the maximum observed frequency f max It can be calculated using the following formula (2).

[0171] [Mathematical formula 2]

[0172]

[0173] At this time, in the gate length N, the time length of the signal to be analyzed for frequency is N×Δt. This time length needs to be greater than m×T, the m-th round trip time of the elastic wave. Therefore, the lower limit of the gate length N is determined by the following formula (3).

[0174] [Mathematical formula 3]

[0175]

[0176] The upper limit of the gate length N is determined based on, for example, the input interval of the elastic wave of the input unit 101 or the time during which the attenuation of the acceleration signal is observed to be greater than a certain value.

[0177] The amplitude spectrum of A(k) can be calculated using the absolute value |A(k)| of A(k).

[0178] (Distance Characteristics Calculation Unit 202)

[0179] The distance characteristic calculation unit 202 converts the frequency characteristic calculated by the frequency analysis unit 201 into a distance characteristic.

[0180] As a method of converting frequency characteristics into distance characteristics, for example, a wavelength calculated based on the speed of sound and frequency can be used as the distance, or the relationship between the thickness and frequency of the refractory brick 16 can be obtained in advance through simulation and stored in the storage unit 203, the relationship between the thickness and frequency can be read from the storage unit 203 and the frequency can be converted into distance.

[0181] ((Calculation of distance characteristics by distance characteristic calculation unit 202))

[0182] As a method for the distance characteristic calculation unit 202 to calculate the distance characteristic, a method of calculating the distance characteristic using the speed of sound will be described.

[0183] The frequency f at the sampling number k of the amplitude spectrum |A(k)| calculated by the frequency analysis unit 201 k It can be calculated using the following formula (4).

[0184] [Formula 4]

[0185]

[0186] When the speed of sound is set to c, the wavelength λ k It can be calculated using the following formula (5).

[0187] [Formula 5]

[0188]

[0189] At this time, the distance characteristic F(λ k ) is determined using the following formula (6).

[0190] [Mathematical formula 6]

[0191] F(λ k )=|A(k)| (6)

[0192] (Storage Unit 203)

[0193] The storage unit 203 stores, for example, the acceleration signal measured by the receiving unit 102 , the processing results of each unit of the control unit 103 , and various data used in the processing.

[0194] The storage unit 203 is composed of a storage device such as a RAM (Random Access Memory) or a hard disk.

[0195] (Map Generating Unit 204)

[0196] The map generation unit 204 generates a map indicating the likelihood accuracy of the reflection position of the elastic wave 21 in the firebrick 16 (that is, the likelihood of the reflection position) based on the distance characteristic calculated by the distance characteristic calculation unit 202 .

[0197] In this embodiment, as described below, the map generation unit 204 first calculates the likelihood of the reflection position using the distance characteristic calculated by the distance characteristic calculation unit 202, and then generates a map indicating the calculated likelihood of the reflection position.

[0198] ((Calculation of likelihood of reflection position at an arbitrary point by the map generation unit 204))

[0199] Reference Fig.14 and Fig.15 A method for the map generation unit 204 to calculate the likelihood of a reflection position at an arbitrary point R of the firebrick 16 will be described.

[0200] Fig.14 It is a perspective view showing the furnace wall 11 in a state where the receiving portion 102 is attached to the iron sheet 12 . Fig.15 It is a schematic diagram of the distance characteristics calculated by the distance characteristics calculation unit 202.

[0201] exist Fig.14 In the example, the spatial coordinates of the installation position of the receiving unit 102 are (xp, yp, zp), and the spatial coordinates of any point R in the refractory brick 16 are (x r ,y r , z r ).

[0202] At this time, the distance d between the point R of the refractory brick 16 and the installation position of the receiving part 102 is r It can be calculated using the following formula (7).

[0203] [Formula 7]

[0204]

[0205] The distance d r F(d r ), the likelihood L(x r ,y r , z r ) can use distance d r The distance characteristic F(d r ), calculated using the following formula (8).

[0206] [Mathematical formula 8]

[0207]

[0208] It should be noted that k=0, 1, ..., N-1.

[0209] Here, max(x) is a function for calculating the maximum element in the parentheses.

[0210] Next, refer to Fig.16 A method in which the map generation unit 204 calculates the likelihood of a reflection position at an arbitrary point R of the firebrick 16 when the plurality of reception units 102 receive the reflected wave 22 at a plurality of positions will be described.

[0211] Fig.161 is a perspective view showing the furnace wall 11 in a state where M receiving parts 102 are mounted on the iron sheet 12 .

[0212] exist Fig.16 In the figure, the spatial coordinates of the installation position of the receiving unit 102 are (x p0 ,y p0 , z p0 ), (x p1 ,y p1 , z p1 ),…,(x pM-1 ,y pM-1 , z pM-1 ), the spatial coordinates of any point R in the refractory brick 16 are (x r ,y r , z r ).

[0213] At this time, the distance d between the point R of the refractory brick 16 and the installation position of the mth receiving portion 102 is rm It can be calculated using the following formula (9).

[0214] [Mathematical formula 9]

[0215]

[0216] It should be noted that m=0, 1, ..., M-1.

[0217] The distance d rm F(d rm ), the likelihood L(x r ,y r , z r ) can use distance d rm The distance characteristic F(d rm ), calculated using the following formula (10).

[0218] [Formula 10]

[0219]

[0220] ((Generation of a map by the map generation unit 204))

[0221] The map generation unit 204 generates a map that visualizes the magnitude of the likelihood of the reflection position.

[0222] As a mapping diagram, a two-dimensional or three-dimensional mapping diagram is preferred. In the present embodiment, a heat map is selected as an example of a mapping diagram. The heat map of the present embodiment uses the distance from the measurement point as the vertical axis and the horizontal axis, and depicts the amplitude (intensity) with light and dark. The heat map can express the size of the likelihood of the reflection position with hue. The heat map can be a three-dimensional heat map, or it can be a two-dimensional heat map of any section selected by the user of the state visualization device 1A.

[0223] <Display unit 104>

[0224] The display unit 104 displays the heat map 401 generated by the map generation unit 204 , a UI (User Interface) for operating the state visualization device 1A, and the like.

[0225] Fig.17 4 is a schematic diagram showing the display unit 104 displaying the heat map 401 .

[0226] The display unit 104 is composed of, for example, an LCD (Liquid Crystal Display), an organic EL display (Organic Electro Luminescence Display, OELD), or the like.

[0227] <Processing of Status Visualization Device 1A>

[0228] use Fig.18 The processing executed in the status visualization device 1A will be described.

[0229] Fig.18 This is a flowchart showing an example of the flow of processing in the state visualization device 1A.

[0230] First, the receiving unit 102 receives a reflected wave signal (step S100 ).

[0231] Next, the frequency analysis unit 201 receives the reflected wave signal from the receiving unit 102, performs frequency analysis on the received signal, and calculates an amplitude spectrum (step S101).

[0232] Next, the distance characteristic calculation unit 202 converts the amplitude spectrum calculated by the frequency analysis unit 201 into a distance characteristic (step S102 ).

[0233] Next, the map generation unit 204 calculates the likelihood of the reflection position in the firebrick 16 using the distance characteristic calculated by the distance characteristic calculation unit 202 (step S103).

[0234] The map generation unit 204 determines whether the likelihood of the reflection position is calculated at all points in the firebrick 16 (step S104). If the likelihood of the reflection position is not calculated at all points (step S104: No), the calculation of the likelihood of the reflection position is repeated (step S103).

[0235] It should be noted that, when the likelihood of the reflection position has not been calculated at all points (No in step S104), the reflected wave may be received again at the same receiving unit 102 or a different receiving unit 102 (step S100). In this case, the amplitude spectrum is then calculated (step S101), the calculated amplitude spectrum is converted into a distance characteristic (step S102), and the likelihood of the reflection position is calculated using the distance characteristic (step S103).

[0236] When the likelihood of the reflection position is calculated at all points (Yes in step S104), the map generation unit 204 generates a map reflecting the magnitude of the likelihood of the reflection position (step S105). In this embodiment, the map generation unit 204 generates a heat map 401 reflecting the magnitude of the likelihood of the reflection position in shades.

[0237] Next, the control unit 103 drives and controls the display unit 104 to display the map generated by the map generating unit 204 on the display unit 104 (step S106 ). In this embodiment, the control unit 103 drives and controls the display unit 104 to display the heat map 401 generated by the map generating unit 204 on the display unit 104 .

[0238] [Other embodiments (embodiment B)]

[0239] Next, another embodiment (referred to as "embodiment B") will be further described.

[0240] Regarding Embodiment B, only the points different from Embodiment A will be described. Specifically, Embodiment B is different from Embodiment A in that the distance characteristic calculation unit 202 is used.

[0241] (Distance Characteristics Calculation Unit 202)

[0242] The following describes a method in which the distance characteristic calculation unit 202 obtains the relationship between the thickness and frequency of the refractory brick 16 by simulation in advance and stores it in the storage unit 203, reads the relationship between the thickness and frequency from the storage unit 203, and converts the frequency into a distance.

[0243] ((Calculation of distance characteristics by distance characteristic calculation unit 202))

[0244] As a method for the distance characteristic calculation unit 202 to calculate the distance characteristic, a method of calculating the distance characteristic using the excitation simulation result based on the finite element method will be described.

[0245] The finite element method is a numerical analysis method for approximately solving differential equations, and it divides a continuum into elements of finite size and performs calculations. The propagation motion of ultrasonic waves in a continuum is expressed by the differential equation shown in the following equation (11).

[0246] [Mathematical formula 11]

[0247]

[0248] Here, ρ is the density, σ is the stress, x is the coordinate, i and j are the numbers of the coordinate axes, b is the object force, u is the displacement, and t is the time.

[0249] When the above equation (11) is divided into elements of finite size, the time t n The ultrasonic propagation motion is expressed using the following formula (12).

[0250] [Mathematical formula 12]

[0251] [M]{u"}+[C]{u′}+[K]{u}={f} (12)

[0252] Here, [M] is the element mass matrix, [C] is the element attenuation matrix, [K] is the element stiffness matrix, {u″} is the acceleration vector, {u′} is the velocity vector, {u} is the displacement vector, and {f} is the external force vector. Here, there is the following relationship: u″ is the acceleration obtained by differentiating the displacement u twice, and u′ is the velocity obtained by differentiating the displacement u once.

[0253] The distance characteristic calculation unit 202 generates a three-dimensional model of a furnace (blast furnace) divided into elements of finite size. The three-dimensional model of the furnace may be the entire furnace. In addition, the three-dimensional model of the furnace may be only the refractory bricks 16 whose thickness is measured and the outer layer area of ​​the refractory bricks 16. The distance characteristic calculation unit 202 generates a plurality of three-dimensional models of refractory bricks 16 with different thicknesses.

[0254] The distance characteristic calculation unit 202 sequentially calculates the ultrasonic wave propagation motion of the above-mentioned equation (12) using each generated three-dimensional model.

[0255] The three-dimensional model of the thickness T of the refractory brick 16 is used to simulate the ultrasonic propagation motion. As a result, the acceleration signal observed at the acceleration measurement position {xp} is set to a T xp(n). At this time, a T The discrete Fourier transform of xp(n)A T xp(k) can be calculated using the following formula (13).

[0256] [Mathematical formula 13]

[0257]

[0258] It should be noted that k=0, 1, ..., N-1.

[0259] The distance characteristic calculation unit 202 calculates the distance characteristic according to A Txp (k) The resonance frequency f at the thickness T of the refractory brick 16 is calculated using the following formula (14): T .

[0260] [Formula 14]

[0261]

[0262] It should be noted that k=0, 1, ..., N-1.

[0263] Here, argmax(x) is a function for calculating the parameter of the lower part of argmax that maximizes the element in the parentheses.

[0264] The distance characteristic calculation unit 202 performs the calculation of the above-mentioned formula (14) at the thickness T of each refractory brick 16, thereby deriving a function that converts the thickness T of the refractory brick 16 and the resonance frequency f.

[0265] The distance characteristic calculation unit 202 can perform simulation at each thickness of the refractory brick 16 with a desired thickness resolution, and derive a function that makes a one-to-one correspondence between the thickness of the refractory brick 16 and the resonance frequency. Alternatively, simulation can be performed at a representative point to derive an approximate formula for converting the thickness of the refractory brick 16 and the resonance frequency.

[0266] Description of Reference Numerals

[0267] 1.1A: Status visualization device

[0268] 11: Furnace wall

[0269] 12: Ironhide

[0270] 13: Monolithic refractory

[0271] 14: Copper Plate

[0272] 15: Monolithic refractory

[0273] 16: Refractory Brick

[0274] 17: Hole

[0275] 18: Terminal

[0276] 19: Crack

[0277] 21: Elastic waves

[0278] 22: Reflected Wave

[0279] 101: Input

[0280] 102: Receiving Department

[0281] 103: Control Department

[0282] 104: Display unit

[0283] 201: Frequency Analysis Department

[0284] 202: Distance characteristic calculation unit

[0285] 203: Storage

[0286] 204: Mapping diagram generation unit

[0287] 401: Heatmap (mapping)

Claims

1. A method for visualizing the state of refractory materials, wherein: include: The step of inputting elastic waves into a furnace wall having a refractory material; A step of receiving a reflected wave of the elastic wave; A step of obtaining the frequency characteristic of the reflected wave; A step of obtaining a distance characteristic based on the frequency characteristic; as well as A step of generating a map indicating the likelihood of a reflection position in the refractory material based on the distance characteristic.

2. The method for visualizing the state of a refractory material according to claim 1, wherein: The distance characteristic comprises a plurality of distance characteristics, The map is generated by synthesizing the maps created according to the plurality of distance characteristics.

3. A method for repairing a refractory material, wherein: The refractory is repaired based on the map generated by the method for visualizing the state of the refractory according to claim 1 or 2.

4. A device for visualizing the state of refractory materials, comprising: An input portion for inputting elastic waves into a furnace wall having a refractory material; a receiving unit, receiving a reflected wave of the elastic wave; and The control unit obtains a frequency characteristic of the reflected wave, obtains a distance characteristic from the frequency characteristic, and generates a map indicating the likelihood of a reflection position in the refractory material based on the distance characteristic.

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