Molten iron level measuring device and level measuring method

Abstract

To reduce the load of antenna adjustment work when measuring the level of hot metal using a microwave range finder and to enable stable level measurement.SOLUTION: A level measurement device for hot metal includes a scanning microwave range finder that measures a distance to an object within a scanning range. The microwave range finder is arranged above a torpedo car 11 into which hot metal is injected. The scanning range is set to include a hot metal inlet 13 formed in the torpedo car 11 and the upper surface of the torpedo car 11.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a level measurement device and a level measurement method for measuring the level of molten iron in a torpedo car. [Background technology]

[0002] In the steelmaking process, there is a step in which molten pig iron tapped from a blast furnace is received in a torpedo car, and in this step, the molten pig iron is poured into the furnace body through a pouring port formed on the top surface of the torpedo car. Conventionally, in this torpedo car receiving step, the molten pig iron level in the torpedo car is measured.

[0003] As a device for measuring the level of molten pig iron, Patent Document 1 discloses a microwave distance meter in which a guide pipe and a reflector are disposed above an object to be detected. In the device described in Patent Document 1, microwaves propagating inside the guide pipe are reflected by the reflector, and the reflected microwaves are irradiated onto the molten pig iron, thereby measuring the level of the molten pig iron.

[0004] Patent Document 2 discloses a radar device that measures the molten iron level in a torpedo car. Patent Document 2 discloses a technology that selects only the reflected microwaves that are reflected by the object to be measured and return directly to the antenna, even if the irradiated microwaves are reflected by the sidewall or the like, and determines the distance from the antenna to the object to be measured.

[0005] Patent Document 3 discloses a molten iron level measuring device in which a cooling chamber is provided above the position where the molten iron is received and a microwave level meter is attached to the top of this cooling chamber. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-178207 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-243845 [Patent Document 3] Japanese Utility Model Application Publication No. 56-088121 Summary of the Invention [Problem to be solved by the invention]

[0007] In measuring the molten iron level using the devices described in Patent Documents 1 to 3, microwaves are irradiated toward the molten iron in a torpedo car or a molten iron ladle, but in all of these documents, the microwaves are irradiated at only one point, i.e., the molten iron level is measured at only one point.

[0008] However, when the torpedo car moves to the pig iron receiving position, the stopping position of the torpedo car may deviate from the predetermined stopping position. In this case, in a conventional level measurement device that irradiates microwaves at only one point, the microwave irradiation point may deviate from the surface of the molten pig iron in the torpedo car, making it impossible to measure the molten pig iron level.

[0009] In particular, because the injection port of a torpedo car is narrow, if the torpedo car is stopped at a different position from the designated position, the microwave irradiation point is likely to deviate from the injection port. Also, if metal deposits adhere to the injection port or the injection port is deformed due to thermal load, the microwave may not reach the molten iron in the furnace body, making it impossible to measure the molten iron level.

[0010] When such disturbances occur during measurement of the molten iron level, it is necessary to adjust the antenna orientation of the microwave distance meter. However, because microwaves are invisible, it is not easy to determine the appropriate direction and amount of adjustment for the antenna orientation. Therefore, responding to the above disturbances by adjusting the antenna places a heavy burden on the operator.

[0011] Therefore, it is desirable to be able to stably measure the molten iron level while reducing the burden of adjusting such antennas.

[0012] The present invention has been made in consideration of the above circumstances, and aims to reduce the burden of antenna adjustment work and enable stable level measurement when measuring the level of molten iron using a microwave distance meter. [Means for solving the problem]

[0013] The present invention, which solves the above-mentioned problems, is a molten iron level measuring device, By scanning microwaves The invention is characterized in that it is provided with a scanning microwave distance meter that measures the distance to an object within a scanning range, the microwave distance meter being provided above a torpedo car into which the molten iron is injected, and the scanning range being set to include the molten iron injection port formed in the torpedo car and the upper surface of the torpedo car.

[0014] The torpedo car may further include a control unit for controlling the microwave distance meter, and the control unit may be configured to output a stop signal to stop the injection of the molten iron into the torpedo car when the difference in height between the surface of the molten iron in the torpedo car and the injection port becomes less than a predetermined threshold value.

[0015] The microwave range finder may be an electronically scanned standing wave radar.

[0016] According to another aspect, the present invention provides a method for measuring the level of molten iron, comprising the steps of: By scanning microwaves This method is characterized by using a scanning microwave distance meter that measures the distance to an object within a scanning range, transmitting microwaves from above the torpedo car so that the scanning range includes the molten iron inlet formed on the torpedo car into which the molten iron is injected and the top surface of the torpedo car, and measuring the level of the molten iron based on height information within the scanning range.

[0017] When the difference in height between the surface of the molten iron in the torpedo car and the injection port becomes less than a predetermined threshold value, the injection of the molten iron into the torpedo car may be stopped.

[0018] The microwave range finder may be an electronically scanned standing wave radar. [Effects of the Invention]

[0019] According to the present invention, when measuring the level of molten iron using a microwave distance meter, the load of antenna adjustment work can be reduced and level measurement can be carried out stably. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is an explanatory diagram for explaining a schematic configuration of a level measurement device according to an embodiment of the present invention; [Figure 2] FIG. 1 is a top view of a torpedo car for explaining an example of a microwave scanning range. [Figure 3] 3 is a diagram schematically showing the distance measurement results obtained when microwaves are irradiated in the scanning range of FIG. 2. FIG. [Figure 4] FIG. 10 is an explanatory diagram showing microwave irradiation points in a conventional level measurement device. [Figure 5] FIG. 1 is a top view of a torpedo car for explaining an example of a microwave scanning range. [Figure 6] 6 is a diagram schematically showing the distance measurement results obtained when microwaves are irradiated in the scanning range of FIG. 5. FIG. [Figure 7] FIG. 1 is a top view of a torpedo car for explaining an example of a microwave scanning range. [Figure 8] FIG. 8 is a diagram schematically showing distance measurement results obtained when microwaves are irradiated in the scanning range of FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals, and redundant description will be omitted.

[0022] Figure 1 is an explanatory diagram for explaining the schematic configuration of a level measurement device according to one embodiment of the present invention. A torpedo car 11 has an inlet 13 formed on the top surface of a furnace body 12, through which molten pig iron 10 is poured. The torpedo car 11 shown in Figure 1 is stopped at the pig iron receiving position, and during the process of receiving the pig iron, the molten pig iron 10 flows down a tilting runner 14 and is poured into the furnace body 12 through the inlet 13.

[0023] The level measurement device 1 includes a microwave distance meter 2 provided above the furnace body 12 of the torpedo car 11. The microwave distance meter 2 is arranged inside the cast floor 15 of the blast furnace. The cast floor 15 is assembled with a plurality of steel beams (not shown), and the microwave distance meter 2 is arranged between these steel beams.

[0024] The microwave distance meter 2 is a scanning type microwave distance meter that measures the distance to an object within a scanning range (within a scanning line) by scanning microwaves. In this embodiment, a two-dimensional microwave distance meter is used as the microwave distance meter 2, but a three-dimensional microwave distance meter may also be used.

[0025] The microwave distance meter 2 according to this embodiment includes a microwave transmitter / receiver 3 and an antenna 4 connected to the microwave transmitter / receiver 3.

[0026] In the microwave distance meter 2 configured as described above, microwaves generated by the microwave transmitter / receiver 3 are transmitted downward from the antenna 4. The transmitted microwaves scan a predetermined range, and echoes (reflected waves) reflected by the object to be measured (for example, the molten iron 10 or the furnace body 12 of the torpedo car 11) are received by the microwave transmitter / receiver 3 via the antenna 4. Then, based on the signal strength of the received microwaves, the distance from the antenna 4 to the object to be measured within the scanning range is measured.

[0027] The microwave scanning range is set in advance before the start of operation and is determined appropriately depending on the shape of the furnace body of the torpedo car 11 to be used, the shape of the injection port, etc. Specific scanning ranges will be described later. The microwave distance meter 2 is not limited to the configuration described in this embodiment, and known configurations can be applied. For example, the microwave distance meter 2 may be configured to irradiate the molten iron 10 with microwaves transmitted horizontally and reflected by a reflector.

[0028] The microwave scanning method may be electronic scanning or mechanical scanning, but since the microwave rangefinder 2 is used in a dusty environment, it is preferable to use electronic scanning rather than mechanical scanning, which has many moving parts. Also, the microwave rangefinder 2 may be an electronically scanned standing wave radar, or may be a pulse radar or FMCW radar.

[0029] The level measurement device 1 according to this embodiment includes a control unit 100. The control unit 100 is, for example, a computer equipped with a CPU, a memory, etc., and has a program storage unit (not shown). The program storage unit stores programs that control various processes that are executed based on the measurement results of the microwave distance meter 2. The programs may be recorded on a computer-readable storage medium and installed into the control unit 100 from the storage medium.

[0030] The level measurement device 1 according to this embodiment is configured as described above. Next, a method for measuring the molten iron level using this level measurement device 1 will be described.

[0031] Figure 2 is a top view of a torpedo car to explain an example of the microwave scanning range. The two-dot chain line in Figure 2 indicates the microwave scanning range. In the example of Figure 2, the microwave scanning range extends in the furnace width direction (X-axis direction) of the torpedo car 11 stopped at the pig iron receiving position, and this scanning range includes the injection port 13 and the upper surface of the furnace body 12 near the injection port 13. In addition, since the setting position of the scanning range in the furnace length direction (Y-axis direction) is located at the center of the injection port 13, the scanning range also includes the molten iron 10 flowing from the bottom end of the tilting runner 14 (Figure 1) toward the injection port 13.

[0032] FIG. 3 is a diagram showing the distance measurement results obtained when microwaves are irradiated within the above-mentioned scanning range. When measuring the molten iron level, the surface of the molten iron in the furnace body 12 is identified based on the distance measurement results shown in FIG. 3.

[0033] 3 correspond to points A to D shown in FIG. 2. The vertical axis in FIG. 3 indicates the height with the bottom surface of the furnace body 12 as the reference point (zero point). This reference point is set, for example, as follows: First, the empty torpedo car 11, which has not yet been poured into the furnace body 12, is moved to the iron receiving position. Next, microwaves are irradiated toward the pouring port 13, and the distance from the antenna 4 is measured. The point farthest from the antenna 4 is then set as the reference point, which is the bottom surface of the furnace body 12.

[0034] According to the distance measurement results shown in Figure 3, the height of the region between A and B gradually decreases, and therefore it can be determined that the height of the region between A and B is the height of the molten iron 10 being poured from the lower end of the tilting runner 14 (Figure 1) to the pouring port 13. Furthermore, since the height of the region between C and D is higher than the height of the region between B and C that follows the region between A and B, it can be determined that the height of the region between C and C is the height of the top surface of the furnace body 12. Furthermore, since the height of the region between B and C is the height of the region sandwiched between the region between A and B, which indicates the poured molten iron 10, and the region between C and C, which indicates the top surface of the furnace body 12, it can be determined that it is the height of the surface of the molten iron 10 in the furnace body 12. In other words, the height of the region between B and C is the molten iron level in the furnace body 12.

[0035] As described above, in the level measurement device 1 according to this embodiment, the microwave scanning range is not limited to the injection port 13 but also includes the upper surface of the furnace body 12, so that the distance measurement results within the scanning range form a plurality of regions with different heights from the reference point. Then, based on the height information of these plurality of regions, the surface of the molten iron 10 in the furnace body 12 is identified and the molten iron level is measured.

[0036] According to this method for measuring the molten iron level, the molten iron level can be measured stably even if disturbances such as deviation of the stopping position of the torpedo car 11, adhesion of ingots to the injection port 13, or thermal deformation of the injection port 13 occur. The reason for this is as follows.

[0037] In the case of a conventional level measurement method shown in Fig. 4 in which microwaves are irradiated only at one point on the surface of the molten pig iron in the furnace body 12, if a disturbance such as that described above occurs, the microwaves are likely to fail to reach the surface of the molten pig iron in the furnace body 12, and the molten pig iron level may not be measured. On the other hand, in the molten pig iron level measurement method of this embodiment, microwaves are irradiated over a range rather than a single point. Therefore, even if a disturbance occurs, at least a part of the scanning range includes the surface of the molten pig iron in the furnace body 12, and the molten pig iron level can be measured in that area. In other words, since the molten pig iron level can be measured stably even if a disturbance occurs, the robustness of the level measurement device 1 is improved. Furthermore, the antenna adjustment work required in conventional level measurement devices when a disturbance occurs is no longer necessary.

[0038] The level measurement device 1 may be configured to output a stop signal to a device (not shown) that pours the molten iron 10 from the tilting runner 14 (FIG. 1) based on the molten iron level in the furnace body 12, to stop the pouring of the molten iron 10. As described above, the height of the region between B and C in FIG. 3 indicates the height of the molten iron surface in the furnace body 12, and the region between C and D indicates the height of the upper surface of the furnace body 12. Therefore, the height of point C on the boundary between the region between B and C is the height of the pouring port 13. Therefore, the control unit 100, to which height information within the scanning range is input, calculates the difference Δh between the height of the pouring port 13 and the height of the molten iron surface, and outputs a stop signal for pouring the molten iron when the calculated Δh is less than a predetermined threshold. Then, by stopping the pouring of the molten iron based on the stop signal, it is possible to prevent the molten iron 10 from overflowing from the furnace body 12. Note that the predetermined threshold may be set arbitrarily.

[0039] Even with conventional level measurement methods, it is possible to monitor the molten iron level and output a signal to stop molten iron injection when the molten iron level reaches a predetermined height, taking into account the design height of the injection port 13. However, since the height of the injection port 13 may fall below the design height due to thermal deformation of the furnace body 12, there is a concern that simply monitoring the molten iron level may not output a stop signal even if the height of the injection port 13 falls excessively below the design height.

[0040] On the other hand, the level measurement device 1 according to this embodiment can monitor the distance from the molten iron level to the injection port 13, and therefore can output a signal to stop the injection of molten iron based on the relationship between the molten iron level and the actual height of the injection port 13. That is, even if the height of the injection port 13 drops due to thermal deformation of the furnace body 12, a stop signal is output based on the difference Δh between the lowered height of the injection port 13 and the height of the molten iron surface, so that the overflow of the molten iron 10 in the furnace body 12 can be more reliably prevented.

[0041] Although the level measurement device 1 according to this embodiment has been described above, the scanning range of the microwave is not limited to the range shown in FIG.

[0042] For example, as shown in Fig. 5, the microwave scanning range may be a range extending in the furnace length direction (Y-axis direction). In this example, the scanning range is also set to include the injection port 13 and the upper surface of the furnace body 12 around the injection port 13. Then, from the distance measurement results as shown in Fig. 6, the surface of the molten iron in the furnace body 12 can be identified and the molten iron level can be measured.

[0043] In the above example, the scanning range of the microwaves is a range spanning the injection port 13, but the scanning range does not have to be a range spanning the injection port 13, for example, as shown in Fig. 7. In this example, the scanning range is also set to include the injection port 13 and the upper surface of the furnace body 12 around the injection port 13. Then, from the distance measurement results as shown in Fig. 8, the surface of the molten iron in the furnace body 12 can be identified and the molten iron level can be measured.

[0044] The scanning range of the microwave may be, for example, a diagonal direction in FIG. 2 (a direction between the X-axis direction and the Y-axis direction).

[0045] In the above example, molten pig iron 10 is used as an example of the molten material whose level is to be measured, and the furnace body 12 of the torpedo car 11 is used as an example of the vessel into which the molten pig iron 10 is poured, but the vessel into which the molten pig iron 10 is poured is not limited to the torpedo car 11 and may be, for example, a molten pig iron ladle. Also, for example, the molten material whose level is to be measured may be slag, and the vessel into which the molten material is poured may be a slag ladle.

[0046] Although the present invention has been described above by way of example, it is understood that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and that such modifications and alterations are also within the technical scope of the present invention. [Industrial Applicability]

[0047] The present invention can be applied to measuring the molten iron level in a torpedo car. [Explanation of symbols]

[0048] 1 Level measuring device 2. Microwave rangefinder 3 Microwave transmitter and receiver 4 Antennas 10 Molten iron 11 Mixed iron car 12 Furnace body 13 Inlet 14 Tilting gutter 15 Casthouse

Claims

1. A molten iron level measuring device, A scanning microwave distance meter is provided which measures the distance to an object within a scanning range by scanning microwaves, the microwave distance meter is provided above a torpedo car into which the molten iron is poured, 10. A level measuring device according to claim 9, wherein the scanning range is set to include an inlet for molten iron formed in the torpedo car and an upper surface of the torpedo car.

2. a control unit for controlling the microwave range finder, 2. The level measurement device according to claim 1, wherein the control unit is configured to output a stop signal to stop the injection of the molten iron into the torpedo car when a difference in height between a surface of the molten iron in the torpedo car and the injection port becomes less than a predetermined threshold value.

3. 3. The level measuring device according to claim 1, wherein the microwave distance meter is an electronically scanned standing wave radar.

4. A method for measuring the level of molten iron, comprising: A scanning microwave distance meter is used to measure the distance to an object within the scanning range by scanning microwaves. transmitting microwaves from above the torpedo car so that the scanning range includes a molten iron injection port formed in the torpedo car through which the molten iron is injected and an upper surface of the torpedo car; A level measurement method, characterized in that the level of the molten iron is measured based on height information within the scanning range.

5. 5. The level measurement method according to claim 4, wherein the injection of the molten iron into the torpedo car is stopped when a difference in height between a surface of the molten iron in the torpedo car and the injection port becomes less than a predetermined threshold value.

6. 6. The level measuring method according to claim 4, wherein the microwave distance meter is an electronically scanned standing wave radar.

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