TWI697561B - Method for evaluating melting loss of bottom blowing hole of converter - Google Patents

Abstract

A method for evaluating melting loss of bottom blowing holes of a converter is described. In this method, a recording operation is performed on a bottom in an inner of a converter by using an infrared thermograph, so as to obtain temperature information of the bottom in the inner of the converter. The converter has various bottom blowing holes disposed in the bottom. An area of a low temperature region of each of the bottom blowing holes, and a difference between high temperature and low temperature of each of the bottom blowing holes are calculated by using the temperature information. The health of each of the bottom blowing holes is determined based on the area of the low temperature region of each of the bottom blowing holes, and the difference between high temperature and low temperature of each of the bottom blowing holes.

Description

Evaluation method for melting loss of bottom blow hole in converter

The present invention relates to a method for evaluating the condition of a converter, and more particularly to a method for evaluating the melting loss of the bottom blow hole of the converter.

The converter utilizes the bottom blowing holes arranged at the bottom of the furnace to blow and stir the molten steel in the furnace, thereby effectively improving the uniformity of the molten steel. Therefore, the blowing and stirring process through the bottom blowing hole plays a very important role in the refining process of molten steel. However, the condition of the bottom blow hole of the converter changes greatly. If the bottom blow hole is too deep or the gas flow rate through the bottom blow hole is abnormal, the converter may leak steel at any time.

Steel mills generally use laser thickness gauges to assess bottom blown residual thickness. However, the shooting interval of the laser thickness gauge is too long to analyze the bottom blow residual thickness in real time. For example, a technique for evaluating the degree of melting loss of the converter lining and bottom blow holes is to use a laser thickness gauge to measure the residual thickness of the working bricks at each position of the converter. This technology moves the trolley loaded with the laser device to the front of the converter, and the laser device scans the interior of the converter one by one at different angles, and calculates and depicts the residual thickness data of each shooting location of the converter body. When the online operator found the work bricks around the bottom blow hole If the minimum thickness is too small, the bottom blow hole can be sealed when the furnace is subsequently shut down, so that the melt loss rate of the bottom blow hole can be minimized, so as to achieve the goal of not showing permanent bricks at the end of the entire furnace generation.

However, every time the laser thickness gauge is used for shooting, the device of the laser thickness gauge must be positioned first. The positioning of the device and the subsequent shooting will take about 20 to 30 minutes in total. Therefore, the laser thickness measurement of the converter needs to be carried out during the busy production period. In the early stage of the furnace generation, the laser thickness measurement of the converter is usually carried out about once every 500 furnaces, and in the middle and late stages of the furnace generation with higher risks, the laser measurement of the converter is carried out about every 200 to 300 furnaces. Thick shoot. Therefore, the shortest interval between laser shots is about 1 to 2 weeks. However, the bottom blowing conditions of the converter have changed considerably. If the bottom blowing hole is too deep or the gas flow rate blown by the bottom blowing hole is abnormal, steel leakage may occur at any time. Therefore, because the single shooting time of the laser thickness gauge is too long, the shooting interval is too long and the shooting operation cannot be performed frequently, which becomes a big problem.

Therefore, one object of the present invention is to provide a method for evaluating the melting loss of the bottom blow hole of the converter, which uses infrared thermal imaging camera to collect the temperature information of the bottom position inside the converter, and analyze the low temperature of each bottom blowing block The difference between the area area and the high and low temperature can effectively quantify the health of the bottom blow hole, thereby reducing the risk of the bottom blow hole melting through the steel.

Another object of the present invention is to provide a method for evaluating the melt loss of the bottom blow hole of the converter, in which the infrared camera only needs to be installed at a fixed point Therefore, there is no need to spend the time of equipment positioning, and the time required for the infrared thermal imager to capture and collect the temperature information of the bottom of the converter is very short, so the frequency of shooting the bottom of the converter can be increased. In turn, it can provide fast and immediate analysis feedback, effectively reducing the risk of bottom blow hole melt-through.

According to the above object of the present invention, a method for evaluating the melting loss of the bottom blow hole of the converter is proposed. In this method, an infrared thermal imager is used to record the bottom of the furnace inside the converter to obtain the temperature information of the bottom of the converter. The converter has a plurality of bottom blowing holes arranged in the bottom of the furnace. Use the temperature information to calculate the area of the low temperature area of each bottom blow hole and the difference between the high and low temperature of each bottom blow hole. The health of each bottom blow hole is judged according to the area of these low temperature regions and/or the difference between high and low temperature.

According to an embodiment of the present invention, the converter is in a tapping state during the aforementioned video recording operation.

According to an embodiment of the present invention, when performing the above-mentioned video recording operation, the converter has completed the tapping and slag dumping operations.

According to an embodiment of the present invention, the aforementioned video recording operation lasts for more than one minute.

According to an embodiment of the present invention, the calculation of the area of each low temperature region of each bottom blow hole includes: plotting the temperature information obtained by the infrared thermal imager into a 3D graph, wherein the X axis and Y axis of the 3D graph represent the plane For position, the Z axis of the 3D graph represents temperature, and the 3D graph contains a plurality of low temperature regions corresponding to bottom blow holes. Select the representative value of the background temperature according to the 3D graph. The threshold value is obtained by subtracting the preset temperature value from the representative value of the background temperature. In each low temperature zone of the 3D map In the domain, calculate the cross-sectional area enclosed by the threshold to obtain the low-temperature area of the bottom blow hole.

According to an embodiment of the present invention, the calculation of the high and low temperature difference of each bottom blow hole includes: in each low temperature region of the 3D image, subtract the lowest temperature value of the low temperature region from the representative value of the background temperature to obtain the high and low temperature difference.

According to an embodiment of the present invention, the aforementioned representative value of the background temperature is the highest temperature in a background area in the 3D image, the lowest temperature in the background area, or the average temperature of the background area.

According to an embodiment of the present invention, the aforementioned preset temperature value is about 20°C to about 200°C.

According to an embodiment of the present invention, in the above-mentioned judging the health of each bottom blow hole, when the size of one of the low temperature area areas becomes larger, it represents the size of the bottom blow hole corresponding to the area of the low temperature area The size becomes larger.

According to an embodiment of the present invention, in the above determination of the health of each bottom blow hole, when one of the high and low temperature differences becomes larger, the size of the bottom blow hole corresponding to the one representing the high and low temperature differences becomes larger.

100‧‧‧Operation

110‧‧‧Operation

120‧‧‧Operation

200‧‧‧Converter

200a‧‧‧stove mouth

210‧‧‧Furnace bottom

220‧‧‧Infrared Thermal Imager

300‧‧‧3D drawing

310‧‧‧Low temperature area

320‧‧‧Background area

330‧‧‧Low temperature zone

In order to make the above and other objects, features, advantages and embodiments of the present invention more comprehensible, the description of the accompanying drawings is as follows: [FIG. 1] shows a bottom blowing of a converter according to an embodiment of the present invention Flow chart of the evaluation method of hole melting loss; [FIG. 2A] to [FIG. 2C] are schematic diagrams of the device flow diagram of the bottom blow hole recording operation of a converter according to an embodiment of the present invention; [FIG. 3] is a schematic diagram of an apparatus according to an embodiment of the present invention The graph of the variation curve of the difference between the high and low temperature of each bottom blow hole of the converter with the shooting time; and [Fig. 4] is a partial schematic diagram showing a 3D diagram drawn by a temperature information according to an embodiment of the present invention, where X of the 3D diagram The axis and Y axis represent the plane position, and the Z axis of the 3D graph represents temperature.

In view of the fact that the conventional techniques for using a laser thickness gauge to assess the health of the bottom blow holes of the converter include too long a single shooting time and too long shooting intervals, it is impossible to analyze the bottom blow residual thickness in real time. Therefore, the present invention proposes a method for evaluating the melting loss of the bottom blow holes of the converter. The infrared thermal imager is used to collect the temperature information of the bottom of the converter, and the bottom blow of the bottom of the converter is analyzed based on the temperature information. The area of the low temperature area and the difference between the high and low temperature of the block can effectively quantify the health of the bottom blow holes of the converter and provide fast and real-time analysis feedback.

Please refer to Figure 1 and Figures 2A to 2C, in which Figure 1 shows a flow chart of a method for evaluating the melting loss of the bottom blow hole of a converter according to an embodiment of the present invention, and Figures 2A to 2C show a flow chart according to A schematic flow diagram of an apparatus for evaluating the recording operation of bottom blow holes in a converter according to an embodiment of the present invention. The converter 200 has a plurality of bottom blowing holes (not shown) penetrated in the bottom 210 of the furnace. The melting loss assessment of the bottom blow holes of the converter 200 can be performed after the blowing of the converter 200 is completed. As shown in Figure 2A, during blowing, the converter 200 is in a standing shape, and the converter The furnace mouth 200a of 200 faces upward. In some embodiments, as shown in FIG. 2B, after the converter 200 completes blowing, the converter 200 is tilted to start tapping, and the bottom blow hole maintains the blowing state at this time. The tilt angle of the converter 200 may be, for example, about 0 degrees to 90 degrees.

In some examples, during the period when the converter 200 is tilted out of steel, operation 100 can be performed to use the infrared thermal imaging camera 220 to record the bottom 210 of the interior of the converter 200, and to continuously photograph the bottom 210 for a period of time. In this way, the temperature information of the bottom 210 inside the converter 200 can be obtained. That is, during the recording operation of the furnace bottom 210, the converter 200 is in a tapping state. The temperature information of the furnace bottom 210 includes the temperature of each position of the furnace bottom 210. Please also refer to FIG. 3, which is a graph showing the variation curve of the difference between the high and low temperature of each bottom blow hole of a converter according to an embodiment of the present invention with the shooting time. The difference between the high and low temperature of each bottom blow hole of the converter 200 is maintained at a relatively stable value about one minute after the start of shooting. This also means that the infrared thermal imaging camera 220 can reach a stable state about one minute after starting to shoot and video. Therefore, in some exemplary cases, the recording operation can continue for more than one minute. After the infrared thermal imager 220 completes the shooting, the converter 200 can be turned back into position, as shown in FIG. 2C.

Since the recording operation of the infrared thermal imaging camera 220 on the furnace bottom 210 of the converter 200 takes only about one minute, which can be completed in a relatively short time, the frequency of shooting the furnace bottom 210 of the converter 200 can be greatly increased. This can effectively reduce the risk of the bottom blow hole of the converter 200 melting through the steel.

In the above embodiment, the recording operation of the bottom 210 of the converter 200 using the infrared thermal imager 220 is performed during the period when the converter 200 is tilted out of steel. In other embodiments, the blowing can be completed at the converter 200, and After the tapping and slag dumping operations, the empty converter 200 is then tilted from about 0 degrees to about 90 degrees, and then the infrared thermal imager 220 is used to record the bottom 210 of the converter 200, and the bottom 210 is continuously photographed For more than one minute, the temperature information of the bottom 210 inside the converter 200 can be obtained. In other words, during the recording operation of the furnace bottom 210, the converter 200 has completed the tapping and slag dumping operations and is in an empty furnace state. In these embodiments, the bottom blow hole of the converter 200 maintains the blowing state during the tapping and slagging of the converter 200. The selection of the above two implementation modes can be determined according to the conditions and requirements during production.

Please refer to Figure 1 again. After the recording operation of the bottom 210 of the converter 200 is completed, operation 110 can be performed to use the collected temperature information of the bottom 210 inside the converter 200 to calculate each bottom blow hole of the converter 200 The area of the low temperature zone and the difference between the high and low temperature of each bottom blow hole. In some examples, the temperature information can be drawn into a 3D map first, and then the 3D map can be used to calculate the low temperature area and the difference between the high and low temperatures of each bottom blow hole of the converter 200.

Please refer to FIG. 4 together, which is a partial schematic diagram of a 3D graph drawn by a temperature information according to an embodiment of the present invention, where the X axis and Y axis of the 3D graph represent the plane position, and the Z axis of the 3D graph represents temperature. That is, the X-axis and Y-axis of the 3D diagram 300 are the positions where each position of the furnace bottom is projected onto a plane, and the Z-axis of the 3D diagram 300 represents the temperature distribution of each position of the furnace bottom. The 3D image 300 includes a number of low temperature regions 310, and these low temperature regions 310 respectively correspond to the bottom blow holes of the converter 200. The low temperature region 310 is caused by the phenomenon that the bottom blow hole is not covered by molten steel, and the bottom blow hole blows air to cause local cooling. After the 3D map 300 is created using the collected temperature information of the furnace bottom 210, the representative value of the background temperature can be selected according to the 3D map 300. From 3D map 300 The temperature transition of the graphic can roughly divide the graphic of the 3D image 300 into a background area 320 and a low temperature area 330. The low temperature area 330 is the area roughly corresponding to the bottom blow hole, and the background area 320 is roughly the area outside the bottom blow hole area, for example The internal space of the converter. The representative value of the background temperature is the temperature selected from the background area 320. For example, the representative value of the background temperature may be the highest temperature of the background area 320 of the 3D image 300, the lowest temperature of the background area 320, or the average temperature of the background area 320. In some exemplary examples, the background temperature representative value selects the highest temperature of the background area 320.

The representative value of the background temperature is mainly to provide a reference for calculating the threshold. Therefore, whether it is the highest temperature, lowest temperature, average temperature, or other temperature values helpful for analysis in the background area 320, as long as the calculation of all bottom blow holes of the converter All the selected values of the same type can be used to calculate the threshold. If the standards are the same, the cross-sectional area calculated by the bottom blow hole through the threshold can be compared. Since the furnace temperature of each heat will change, the representative value of the background temperature will vary with different heats. Even, because the bottom temperature distribution of the furnace is not uniform, each bottom blow hole of the same furnace may be different, but in some demonstration examples, it can be unified based on site requirements.

After the representative value of the background temperature is selected, the representative value of the background temperature is used to calculate the threshold. First, determine the preset temperature value according to the selected representative value of the background temperature. The preset temperature value is mainly used in the calculation of the threshold. The threshold is to deduct the invalid temperature interval from the representative value of the background temperature, and the preset temperature value is intended to represent the invalid temperature interval. The preset temperature value is related to the selection of the representative value of the background temperature. Choosing different representative values of the background temperature requires adjusting the preset temperature value so that the calculated threshold can better analyze the size of the bottom blow hole. The smaller the value of the preset temperature, the better the resolution, but if it is too small, Effectively filter out the background, but it is not good; the larger the value of the preset temperature value, the more effective the background filter can be ensured, but the resolution ability will be relatively poor. In some examples, the preset temperature value may be about 20°C to about 200°C. In some exemplary examples, according to the data of the inventors in the previous test generations, the representative value of the background temperature is the highest temperature of the background area 320, and the preset temperature may be about 100°C. After subtracting the preset temperature value from the selected representative value of the background temperature to filter out the background area 320, the threshold value can be obtained.

After the calculation of the threshold is completed, in each low temperature region 310 of the 3D map 300, the cross-sectional area enclosed by the threshold is calculated, and the low temperature region area of the bottom blow hole corresponding to this low temperature region 310 can be obtained. In addition, the background temperature representative value can be used to calculate the high and low temperature difference of each bottom blow hole. In each low temperature region 310 of the 3D map 300, the lowest temperature value of the low temperature region 310 can be obtained by subtracting the lowest temperature value of the low temperature region 310 from the representative value of the background temperature. The low temperature area of the low temperature area 310 of the bottom blow hole is positively correlated with the change of the difference between the high and low temperature. The low temperature area of the bottom blow hole and the high and low temperature difference are too large, indicating that the bottom blow hole may have abnormal melting loss; if the value of the low temperature area and the high and low temperature difference is too small or even 0, it means bottom blowing The hole may be clogged or the residual thickness is insufficient.

Please continue to refer to FIG. 1, after completing the calculation of the low temperature area of the low temperature area 310 of the bottom blow hole and the high and low temperature difference, operation 120 can be performed to determine the low temperature area, high and low temperature difference, or At the same time, the health of each bottom blow hole is judged separately according to the area of the low temperature area and the difference between high and low temperature. In some examples, when judging the health of each bottom blow hole, when the size of the low temperature area of a low temperature area 310 becomes larger, it represents the low The size of the bottom blow hole corresponding to the low temperature region area of the temperature region 310 becomes larger. If the size of the low temperature region area becomes smaller, it may mean that the size of the bottom blow hole corresponding to the low temperature region area of the low temperature region 310 becomes smaller. In addition, when the high and low temperature difference of a low temperature area 310 becomes larger, it means that the size of the bottom blow hole corresponding to the high and low temperature difference becomes larger. If the high and low temperature difference becomes smaller, it may mean that the size of the bottom blow hole corresponding to the high and low temperature difference becomes larger. small. Although the area of the low temperature region of the low temperature region 310 is positively correlated with the difference between high and low temperature, the maximum value of the area of the low temperature region and the difference between high and low temperature may not appear at the same time. Proper maintenance timing for bottom blow holes.

In addition, generally speaking, because each bottom blow hole is circular, the low temperature region 310 of the bottom blow hole is nearly circular in a normal state. Therefore, when the shape of the low-temperature region 310 of the bottom blow hole is abnormal, it may mean that the bottom blow hole has abnormal peeling, which requires special tracking.

In the embodiment of the present invention, the low temperature area of the low temperature area of the bottom blow hole and the difference between the high and low temperature maintain a relatively stable value after the infrared thermal imager starts shooting for about one minute, so the low temperature area of the low temperature area of the bottom blow hole The area and the difference between high and low temperature have been determined for reference. Therefore, it takes only a short time to capture and record the bottom of the converter to obtain the temperature information of the bottom of the converter, which can greatly increase the frequency of shooting and video recording of the bottom of the converter, thereby effectively reducing bottom blow hole melting and leakage Risk of steel.

It can be seen from the above-mentioned embodiments that one of the advantages of the present invention is that the method for evaluating the melting loss of the bottom blow hole of the converter of the present invention uses infrared thermal imaging camera to collect the temperature information of the bottom position inside the converter and analyze each The area of the low temperature area of the bottom blow block and the difference between the high and low temperature can effectively quantify the health of the bottom blow hole, thereby reducing the risk of the bottom blow hole melting through the steel.

As can be seen from the above-mentioned embodiments, another advantage of the present invention is that in the method for evaluating the melting loss of the bottom blow hole of the converter of the present invention, since the infrared thermal imager only needs to be installed and photographed at a fixed point, it does not cost The time required for equipment positioning, and the time required for the infrared thermal imaging camera to capture and collect the temperature information of the furnace bottom of the converter is very short, so it can increase the frequency of shooting the furnace bottom inside the converter, thereby providing fast and real-time analysis Feedback, effectively reducing the risk of bottom blow hole melt-through.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in this technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to those defined by the attached patent application scope.

100‧‧‧Operation

110‧‧‧Operation

120‧‧‧Operation

Claims (10)

A method for evaluating the melting loss of bottom blow holes in a converter includes: using an infrared thermal imaging camera to perform a video recording operation on a bottom of a converter to obtain temperature information of the bottom of the converter, wherein the converter A plurality of bottom blowing holes are arranged in the furnace bottom; the temperature information obtained by the infrared thermal imager is used to calculate the area of a low temperature region of each of the bottom blowing holes and the height of each of the bottom blowing holes Temperature difference; and respectively determine the health of each of the bottom blow holes according to the areas of the low temperature regions and the differences between the high and low temperatures. For example, the method for evaluating the melting loss of the bottom blow hole of the converter in the first item of the scope of patent application, in which the converter is in a tapping state during the recording operation. For example, the method for evaluating the melting loss of the bottom blow hole of the converter in the first item of the scope of patent application, in which the converter has completed the tapping and slagging operations when the recording operation is performed. For example, the method for evaluating the melting loss of the bottom blow hole of the converter in the first item of the scope of the patent application, wherein the recording operation lasts for more than one minute. For example, the method for evaluating the melting loss of the bottom blow hole of the converter in the scope of the patent application, wherein the calculation of the area of each of the low temperature regions of each of the bottom blow holes includes: The temperature information is drawn into a 3D graph, where the X-axis and Y-axis of the 3D graph represent the plane position, the Z-axis of the 3D graph represents the temperature, and the 3D graph includes a plurality of low temperature regions respectively corresponding to the bottom blow holes; Select a background temperature representative value for the 3D map; subtract a preset temperature value from the background temperature representative value to obtain a threshold; and in each of the low temperature regions of the 3D map, calculate one of the thresholds The cross-sectional area obtains the low-temperature area of the low-temperature area of the bottom blow hole. For example, the method for evaluating the melting loss of the bottom blow hole of the converter in the scope of patent application, the calculation of the high and low temperature difference of each bottom blow hole includes: in each of the low temperature regions of the 3D map, The background temperature representative value is subtracted from one of the lowest temperature values in the low temperature area to obtain the high and low temperature difference. For example, the method for evaluating the melting loss of the bottom blow hole of the converter in the scope of the patent application, wherein the representative value of the background temperature is one of the highest temperature in a background area in the 3D map, one of the lowest temperature in the background area, or the The average temperature of one of the background areas. For example, the method for evaluating the melting loss of the bottom blow hole of the converter in item 5 of the scope of patent application, wherein the preset temperature is 20°C to 200°C. For example, the method for evaluating the melting loss of the bottom blow holes of the converter in the scope of the patent application, wherein in judging the health of each of the bottom blow holes, when the size of one of the low temperature regions becomes larger , The size of the bottom blow hole corresponding to the one representing the area of the low temperature regions becomes larger. For example, the method for evaluating the melting loss of the bottom blow hole of the converter in the scope of the patent application, in judging the health of each bottom blow hole, when one of the high and low temperature differences becomes larger, it represents the The size of the bottom blow hole corresponding to the difference in high and low temperature becomes larger.

Images