Apparatus and method for measuring tuyere wear and method for operating a blast furnace

Abstract

To provide a technique capable of accurately measuring tuyere wear levels after use.SOLUTION: A measuring device for measuring a wear level of a tuyere for a blast furnace includes: a plate jig arranged on the tip side of the tuyere with reference to the bottom surface of the tuyere; a rangefinder attached to the plate jig for measuring the position of the tip surface of the tuyere; and a fixing jig for attaching the plate jig to the tuyere. Using this device, the difference between the position of the tuyere tip surface before use, measured in advance, and the position of the tuyere tip surface after use is determined as the tuyere wear level in the method.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technique for measuring the amount of wear of a used tuyere in blast furnace operation. [Background technology]

[0002] Damage to a blast furnace tuyere poses a high risk, as it can lead to water entering the furnace and the tuyere breaking, causing molten material and gas to escape from the furnace. If damage occurs, a sudden shutdown is required, which has a significant impact on costs and production volume. Furthermore, since shutdown and startup work are performed in a water-leaking state, there is a higher risk of operational problems than usual.

[0003] Tuyere protrudes into the blast furnace and is exposed to high temperature atmosphere, so to prevent melting, water channels are provided inside the tuyere body to circulate cooling water. However, it is said that the gas temperature inside the blast furnace can reach a maximum of 2000℃ or more, and even in tuyere with cooling structure, the strength of the base material (tuyere body) is likely to decrease in high temperature atmosphere. Furthermore, it does not have sufficient strength against friction caused by the contents inside the furnace. As a result, wear progresses at the tip of the tuyere, and eventually the tuyere body wears down to the cooling water channel, which can cause problems with leakage of cooling water into the blast furnace.

[0004] As a countermeasure, Patent Document 1 discloses a blast furnace tuyere that has a long life even in a high-temperature atmosphere and whose replacement time can be appropriately determined according to the actual wear state of the tuyere body.

[0005] In addition, tuyere life estimation is very important as a means of managing tuyere to prevent damage, and in order to estimate tuyere life, it is effective to accurately measure the amount of tuyere wear after use. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2004-91887 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, the above-mentioned conventional techniques have the following problems. That is, the technology disclosed in Patent Document 1 can only manage wear at a specific point in the circumferential direction of the tuyere tip. The life of the tuyere is determined by the position of greatest wear, and if that position differs from the position of the temperature sensor, the life of the tuyere cannot be managed accurately.

[0008] Additionally, up until now, the amount of tuyere wear after use has been measured by workers visually placing a graduated ruler against the tuyere. This has caused two problems. First, there is the problem of measurement error. This is due to the fact that the accuracy of reading the scale varies depending on how the ruler is placed and the worker's level of skill. Second, there is the problem of not being able to obtain the desired information. Although what is wanted to be managed is the amount of remaining material up to the cooling water passage at the tip of the tuyere, it is not possible to place the ruler directly against the center of the thickness of the annular tuyere tip face. In other words, the amount of remaining material could not be measured correctly.

[0009] The present invention has been made in view of the above circumstances, and provides an apparatus and method for accurately measuring the amount of tuyere wear after use, and also proposes a method of operating a blast furnace that takes into account the state of tuyere wear. [Means for solving the problem]

[0010] The tuyere wear measuring device of the present invention, which advantageously solves the above-mentioned problems, is a measuring device for measuring the wear of a blast furnace tuyere, characterized in that the measuring device comprises a plate-shaped jig arranged on the tip side of the tuyere with the bottom surface of the tuyere as a reference, a distance meter attached to the plate-shaped jig for measuring the position of the tip surface of the tuyere, and a fixing jig for attaching the plate-shaped jig to the tuyere.

[0011] The tuyere wear amount measuring device according to the present invention is (a) the range finder is a non-contact range finder; (b) the range finder is a laser range finder; (c) the distance meter is adjustable in a radial direction relative to the central axis of the tuyere; (d) the plate-shaped jig is attached to the fixed jig so as to be rotatable about the central axis of the tuyere; This may be a more preferable solution.

[0012] The method for measuring tuyere wear according to the present invention, which advantageously solves the above problem, is characterized in that it uses any of the tuyere wear measuring devices described above, and determines the amount of tuyere wear as the difference between the position of the tuyere tip face before use, which is measured in advance, and the position of the tuyere tip face after use.

[0013] The method for operating a blast furnace according to the present invention, which advantageously solves the above problem, is characterized by including a step of measuring tuyere wear amount by the above-mentioned method for measuring tuyere wear amount, and a step of predicting the life of the tuyere from the measured tuyere wear amount. Effect of the Invention

[0014] According to the device and method for measuring the amount of tuyere wear and the method for operating a blast furnace of the present invention, the position of the tip surface of the tuyere relative to a reference can be accurately measured. As a result, the amount of tuyere wear, i.e., the amount of remaining material, can be accurately measured. This makes it possible to accurately manage the life of the tuyere, which contributes to reducing the frequency of tuyere replacement and preventing accidents, and is industrially useful. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram showing a tuyere wear amount measuring device according to one embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded view of the measuring device according to the embodiment. [Diagram 3] FIG. 1 is a schematic diagram showing a conventional method for measuring the amount of wear at a tip of a tuyere. [Figure 4]1 is a graph comparing the measurement results of the amount of tuyere wear of the same tuyere according to the present embodiment and the conventional method. [Diagram 5] 1 is a graph showing a frequency distribution of maximum wear amounts measured for 15 tuyere pieces by the present embodiment and the conventional method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the embodiments of the present invention will be described in detail. The following embodiments are merely examples of devices and methods for embodying the technical ideas of the present invention, and are not intended to limit the configuration to those described below. In other words, the technical ideas of the present invention can be modified in various ways within the technical scope described in the claims.

[0017] Fig. 1 is a schematic cross-sectional view showing a state in which a tuyere wear measuring device according to one embodiment of the present invention is used, and Fig. 2 is an exploded assembly view showing a schematic view of the measuring device.

[0018] The tuyere 1 is made of copper or a copper alloy, and is formed by casting into a shape known as a shrink cylinder. A cooling water channel 7 is formed inside the tuyere 1. Cooling water is injected from the iron shell side of the blast furnace, i.e., from the bottom surface 3 of the tuyere 1, passes through the cooling water channel 7 to cool the tip 2 of the tuyere 1, and then is discharged from the bottom surface 3 of the tuyere.

[0019] The tuyere wear amount measuring device 10 according to this embodiment includes a plate-shaped jig 11, a distance meter 12, and a fixed jig 13. The plate-shaped jig 11 is fixed at a predetermined position on the tip side of the tuyere 1 in the direction of the central axis 4 of the tuyere 1, with the bottom surface 3 of the tuyere 1 as a reference. The plate-shaped jig 11 is preferably disk-shaped. In addition, the plate-shaped jig 11 is preferably attached to the fixed jig 13 so as to be rotatable about the central axis 4 of the tuyere 1. The shape of the tip 2 of the tuyere 1 changes due to wear. Therefore, the position and shape of the tip 2 of the tuyere 1 after use are different from those of the tip 2 of the tuyere 1 before use, and it cannot be used as a reference. Therefore, by using the bottom surface of the tuyere 1, which is not likely to be worn, as a reference, it is possible to grasp the tip surface position of the tuyere 1 before and after use, that is, the amount of wear, and ultimately the amount of remaining material.

[0020] The range finder 12 is fixed to the plate-shaped jig 11 in order to measure the position of the tip face of the tuyere 1. The range finder 12 can be a contact displacement meter or a non-contact type laser range finder. A non-contact type range finder is preferable because there is no risk of wear. A laser range finder is preferable in terms of accuracy. It is preferable that the measurement value of the range finder 12 can be transmitted to an external device by wired or wireless communication. It is preferable that the mounting position of the range finder 12 can be adjusted in the radial direction with respect to the central axis 4 of the tuyere 1.

[0021] The fixing jig 13 is tightly fixed to the bottom surface of the tuyere 1 which serves as a reference. The fixing jig 13 is preferably screwed to the water supply hole 5 and the drain hole 6 on the bottom surface 3 side of the tuyere 1. By screwing at least two places, and preferably three places or more, the positional accuracy of the measurement by the distance meter 12 is improved. The fixing jig 13 has a shaft portion 15 which passes through the central axis 4 of the tuyere 1, and the plate-shaped jig 11 is rotatably fixed to the tip of the shaft portion 15. The plate-shaped jig 11 and the fixing jig 13 are preferably made of aluminum or an aluminum alloy as they are lightweight and easy to handle.

[0022] Next, a method for measuring the amount of tuyere wear according to another embodiment will be described. The above-mentioned measuring device can be suitably applied.

[0023] (1) First, in order to measure the position of the tip face of the tuyere 1, the tip of the tuyere 1 is placed sideways. If the tip face of the tuyere 1 is placed facing downwards, for example on a surface plate, it is difficult to measure the central part in the thickness direction of the annular tip face, which is the part that needs to be measured the most. On the other hand, in order to point the tip of the tuyere 1 upwards, it is necessary to hoist the tuyere 1. However, since a typical tuyere weighs approximately 300 kg, the task of pointing the tuyere 1 upwards is an extremely heavy task.

[0024] (2) The shaft 15 of the fixing jig 13 of the measuring device 10 is inserted along the central axis 4 of the tuyere 1, and the fixing jig 13 is installed on the bottom surface 3 of the tuyere 1, which serves as the reference surface. The fixing jig 13 is fixed to the water supply and drainage ports 5 and 6 of the tuyere 1 with screws. (3) The center of rotation of the plate-shaped jig 11 is rotatably fixed to the tip of the shaft of a fixing jig 13 which penetrates the inside of the tuyere 1 and protrudes outside the tip. (4) A distance meter 12 is installed at a predetermined position in the radial direction with respect to the central axis 4 of the tuyere 1 on the plate-shaped jig 11 . (5) Using the distance meter 12, the distances to multiple points in the circumferential direction are measured as tip surface positions in the same radial direction of the tip surface of the tuyere 1.

[0025] The tip face position of tuyere 1 before use is measured in advance using the above method, and the tip face positions of the corresponding radial coordinates and circumferential coordinates of tuyere 1 after use are similarly measured using the above method, and the difference in distance is taken as the amount of tuyere wear. For the tip face of tuyere 1 which forms an annular shape, the amount of tuyere wear is measured at a total of 24 points in each of eight directions in the circumferential direction, for example, on the inner circumference, outer circumference and thickness center in the radial direction from the central axis 4, and the maximum value is taken as the maximum amount of wear.

[0026] Furthermore, a method for operating a blast furnace according to another embodiment will be described. The blast furnace operating method according to this embodiment includes a step of measuring the amount of tuyere wear by the above-mentioned method for measuring the amount of tuyere wear, and a step of predicting the life of the tuyere 1 from the measured amount of tuyere wear.

[0027] In the step of measuring the amount of tuyere wear, the position of the tip face of the tuyere 1 before use measured in advance is compared with the position of the tip face of the tuyere 1 after use according to the above-mentioned method for measuring the amount of tuyere wear, and the amount of tuyere wear is measured. Here, the amount of tuyere wear can be expressed as a percentage of the wall thickness from the inner surface of the cooling water channel to the tip face of the tuyere 1.

[0028] In the step of predicting the tuyere lifespan, the maximum amount of wear is extracted from the obtained amount of tuyere wear, the amount of remaining material up to the cooling water channel is determined, and the period until the amount of remaining material becomes 0 is calculated as the tuyere lifespan. Here, the service life of the tuyere can be estimated by the following formula. Tuyere lifespan = (number of days the tuyere is used [days]) / (tuyere wear [%] / 100)

[0029] For example, assuming that the thickness of the tip 2 of the tuyere 1 before use, that is, the thickness from the inner surface of the cooling water channel to the tip surface of the tuyere 1, is 100%, if the amount of remaining material after use exceeds 40%, the next tuyere replacement time is extended by a specified period. Also, if the amount of remaining material after use is less than 10%, the next tuyere replacement time is shortened by a specified period. If the amount of remaining material is within the range of 10 to 40%, the next tuyere replacement time is the same as the previous time. Thus, it is possible to reduce the frequency of tuyere replacement while suppressing wear and tear problems on the tuyere, thereby improving the efficiency of blast furnace operation. EXAMPLES

[0030] As an example of the invention, a laser distance gauge was used as a measuring device for the amount of tuyere wear according to the above embodiment. The tuyere was measured using 15 pieces of tuyere before use and after 180 days of use that were not worn until the cooling water flow path was exposed. In the method for measuring the amount of tuyere wear according to the above embodiment, the tip of the tuyere was oriented horizontally as shown in FIG. 1. In the above embodiment, 24 points were measured in each of the eight directions in the circumferential direction shown in the example. In the method for measuring the amount of tuyere wear according to the conventional method (conventional method), the tip of the tuyere was placed on a surface plate facing downward as shown in FIG. 3, and the distance LO from the bottom surface on the outer side of the tuyere to the tip surface and the distance LI from the bottom surface on the inner side to the tip surface were visually measured with a ruler. In the conventional method, a total of 16 points were measured in each of the eight directions in the circumferential direction on the outer side and the inner side. The amount of tuyere wear was calculated from the difference in the measurement results of the tuyere before use and after use.

[0031] The results are shown in Figures 4 and 5. The invention example showed less variation in the amount of wear compared to the conventional method, demonstrating that the measurements were made appropriately. With the conventional method, there was a risk that the amount of wear would be overestimated, leading to increased frequency of tuyere replacement, or that it would be underestimated, leading to problems with tuyere damage such as cooling water leaks.

[0032] In addition, Table 1 shows the results of a comparison between the above embodiment (invention example) and the conventional method for the same tuyere, at the same measurement point of the same tuyere, by five workers (A to E). The results in Table 1 show that the invention eliminates human error and improves measurement accuracy compared to the conventional method.

[0033] [Table 1] [Explanation of symbols]

[0034] 1 Tuyere body 2 (Tuyeres) Tip 3 (Tuyere) Bottom 4 (tuyere) central axis 5 Water supply hole 6 Drain hole 7 Cooling water channel 10. Measuring Equipment 11 Plate-shaped jig 12 Rangefinder 13 Fixture 14 Screws 15 Shaft

Claims

1. A measuring device for measuring the amount of wear of a blast furnace tuyere, The measuring device is a device for measuring tuyere wear amount, comprising a plate-shaped jig arranged on the tip side of the tuyere with the bottom surface of the tuyere as a reference, a distance meter attached to the plate-shaped jig for measuring the position of the tip surface of the tuyere, and a fixing jig for attaching the plate-shaped jig to the tuyere.

2. The device for measuring tuyere wear according to claim 1 , wherein the distance meter is a non-contact distance meter.

3. The device for measuring tuyere wear according to claim 2 , wherein the distance meter is a laser distance meter.

4. The device for measuring the amount of tuyere wear according to claim 1 , wherein the distance meter is adjustable in a radial direction relative to a central axis of the tuyere.

5. The plate-shaped jig is attached to the fixed jig so as to be rotatable about the central axis of the tuyere. The device for measuring tuyere wear according to claim 1.

6. The device for measuring tuyere wear according to claim 1 , wherein the fixing jig is fixed to any one of the water supply and drainage ports on the bottom surface side of the tuyere with a screw.

7. Using the device for measuring the amount of tuyere wear according to any one of claims 1 to 6, A method for measuring tuyere wear in which the difference between the position of the tuyere tip face before use, measured in advance, and the position of the tuyere tip face after use is taken as the amount of tuyere wear.

8. A step of measuring the amount of tuyere wear by the method for measuring the amount of tuyere wear according to claim 7; predicting the life of the tuyere from the measured amount of tuyere wear; A method of operating a blast furnace, including:

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