Method for predicting generation of horizontal hole, method for controlling tap hole opener, and method for operating blast furnace

Abstract

To provide a method for predicting generation of a horizontal hole, which can predict whether or not the horizontal hole is generated when performing hole opening work of a tap hole.SOLUTION: A method for predicting generation of a horizontal hole according to the present invention predicts whether or not the horizontal hole is generated when a tap hole of a blast furnace is opened using a hydraulically driven tap hole opener that drills the tap hole by combining functions of feed, rotation, and impact of a drill rod. The method for predicting generation of the horizontal hole includes: a detection step of detecting a rotation oil pressure when the tap hole is opened; and a determination step of determining that the horizontal hole is likely to be generated when the rotation oil pressure detected in the detection step is equal to or higher than a predetermined value.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for predicting the occurrence of a horizontal hole, a method for controlling a taphole opening machine, and a method for operating a blast furnace. [Background technology]

[0002] Typically, when discharging molten metal and slag generated in a blast furnace, a taphole is opened by drilling through the refractory (mud material) filled in the taphole using a drilling machine. Once the molten metal and slag have been discharged from the taphole, the taphole is closed by filling it with refractory again. If molten metal and slag remain in the blast furnace, they can impair the gas permeability of the furnace, resulting in problems such as an increase in the coke rate (increased production costs) and a decrease in the blast flow rate (decreased production volume). Therefore, it is necessary to open the taphole without any problems and smoothly discharge the molten metal and slag generated in the blast furnace through the taphole. However, depending on the type of refractory and the taphole opening method, horizontal holes (cracks) can form in the refractory, which can cause problems with the discharge of molten metal and slag. When a horizontal hole is formed in the refractory, it is necessary to replace the drill rod of the taphole drilling machine and re-drill the taphole, or to restore the taphole slag discharge state by using oxygen in a taphole drilling process, making it difficult to smoothly discharge the molten metal from the taphole. For this reason, a technology for predicting whether a horizontal hole will be formed when a taphole is drilled has been proposed. Specifically, Patent Document 1 describes a method for determining whether a horizontal hole will be formed during the next taphole drilling operation by comparing the refractory filling speed, filling amount, and filling pressure during the taphole closing operation of a blast furnace with corresponding predetermined thresholds. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-142758 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the method described in Patent Document 1 predicts whether or not a lateral hole will occur during the next drilling operation based on information from the time of taphole plugging operation, but does not predict whether or not a lateral hole will occur while drilling operation is being performed. Therefore, according to the method described in Patent Document 1, if a lateral hole occurs while drilling operation is being performed, an after-the-fact response is necessary. Against this background, there has been a demand for a technology that can predict whether or not a lateral hole will occur while drilling operation is being performed.

[0005] The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for predicting whether a lateral hole will occur during taphole drilling work. Another object of the present invention is to provide a method for controlling a taphole drilling machine and a method for operating a blast furnace that can reduce the rate of lateral holes occurring. [Means for solving the problem]

[0006] The method for predicting the occurrence of a lateral hole according to the present invention is a method for predicting whether a lateral hole will occur when a tap hole of a blast furnace is being drilled using a hydraulically driven tap hole drilling machine that drills a tap hole by combining the functions of feeding, rotating, and striking a drill rod, and includes a detection step of detecting rotational oil pressure when the tap hole is being drilled, and a determination step of determining that there is a high possibility of the lateral hole occurring if the rotational oil pressure detected in the detection step is equal to or greater than a predetermined value.

[0007] The determination step may include a step of determining that there is a high possibility of a lateral hole occurring if the rotational oil pressure detected in the detection step is equal to or greater than a predetermined value and the amount of change in the hole depth is equal to or less than a second predetermined value.

[0008] The method for controlling a taphole drilling machine according to the present invention includes a step of stopping the feed of the drill rod or retracting the drill rod when it is determined that there is a high possibility of the lateral hole occurring by the lateral hole occurrence prediction method according to the present invention.

[0009] The blast furnace operating method of the present invention includes a step of stopping the feed of the drill rod or retracting the drill rod when it is determined that there is a high possibility of the horizontal hole occurring by the horizontal hole occurrence prediction method of the present invention. [Effects of the Invention]

[0010] According to the method for predicting the occurrence of a lateral hole of the present invention, it is possible to predict whether or not a lateral hole will occur during taphole drilling work. Furthermore, according to the method for controlling a taphole drilling machine and the method for operating a blast furnace of the present invention, it is possible to reduce the occurrence rate of a lateral hole. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a taphole opening machine. [Figure 2] FIG. 2 is a diagram showing the feed pressure, rotation pressure, and impact pressure of the taphole drilling machine when a horizontal hole occurs during taphole drilling work. [Figure 3] FIG. 3 is a flowchart showing the flow of a hole-opening process according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] 〔concept〕 The inventors of the present invention evaluated the driving hydraulic pressure of a taphole drilling machine 1 as shown in FIG. 1 when a horizontal hole occurred during taphole drilling operations using the taphole drilling machine 1. The taphole drilling machine 1 shown in FIG. 1 is a hydraulically driven taphole drilling machine that drills a taphole by combining the functions of feeding, rotating, and striking a drill rod 2, and the driving force for each function is controlled hydraulically. The drill rod 2 has a hollow structure and is configured to be able to inject water and air or nitrogen from nozzles formed at its tip. By injecting water and air or nitrogen, the refractory filled in the taphole can be cooled and drilled, even if the refractory is hot.

[0013] 2(a) and 2(b) are diagrams showing the feed pressure, rotation pressure, and impact pressure of the taphole drilling machine 1 when a horizontal hole occurs during taphole drilling. As shown in 2(a) and 2(b), when a horizontal hole occurs during taphole drilling, the rotation pressure of the taphole drilling machine 1 rises sharply, even though the change in drilling depth is below a predetermined value. In the example shown in 2(a), the rotation pressure rises regardless of the feed pressure of the taphole drilling machine 1, whereas in the example shown in 2(b), the rotation pressure changes in accordance with the feed pressure of the taphole drilling machine 1.

[0014] Therefore, the inventors of the present invention have conceived the idea that by monitoring the rotational pressure of the taphole drilling machine 1 during taphole drilling, it is possible to predict whether or not a lateral hole will occur during taphole drilling. The flow of a drilling process according to one embodiment of the present invention, which was conceived based on this idea, will be described below. In the embodiment described below, the occurrence of a lateral hole is predicted based on the rotational pressure of the taphole drilling machine 1. However, the occurrence of a lateral hole may also be predicted by taking into account the behavior of the drilling depth and the feed pressure, based on the example shown in Figures 2(a) and 2(b) above.

[0015] [Opening process] Figure 3 is a flowchart showing the flow of a hole-drilling process according to one embodiment of the present invention. The flowchart shown in Figure 3 starts when taphole drilling work using the taphole drilling machine 1 is started, and the hole-drilling process proceeds to step S1. The hole-drilling process shown below is realized by a control device of the taphole drilling machine 1, which is constituted by an information processing device such as a computer, executing a computer program.

[0016] In the process of step S1, the control device detects the hydraulic load of the taphole drilling machine 1. This completes the process of step S1, and the drilling process proceeds to the process of step S2.

[0017] In the process of step S2, the control device determines whether the rotational oil pressure (detected pressure) of the taphole drilling machine 1 is equal to or greater than a set value P1, based on the hydraulic load detected in the process of step S1. The set value P1 is set in advance based on the rotational oil pressure of the taphole drilling machine 1 when a horizontal hole occurs, determined by experiment or the like. If the determination result shows that the rotational oil pressure of the taphole drilling machine 1 is equal to or greater than the set value P1 (step S2: Yes), the control device determines that a horizontal hole is likely to occur, and proceeds with the hole-opening process to the process of step S3. On the other hand, if the rotational oil pressure of the taphole drilling machine 1 is less than the set value P1 (step S2: No), the control device determines that a horizontal hole is unlikely to occur, and proceeds with the hole-opening process to the process of step S6.

[0018] In the process of step S3, the control device stops the feeding of the drill rod 2 of the taphole drilling machine 1 or retracts the drill rod 2 for a predetermined time, thereby completing the process of step S3, and the hole drilling process proceeds to the process of step S4.

[0019] In the process of step S4, the hydraulic load of the taphole drilling machine 1 is detected. This completes the process of step S4, and the drilling process proceeds to the process of step S5.

[0020] In the process of step S5, the control device determines whether the rotational oil pressure (detected pressure) of the taphole drilling machine 1 is equal to or greater than a set value P1 based on the hydraulic load detected in the process of step S4. The set value P1 may be the same as the set value P1 used in the process of step S2, or may be a value smaller than the set value P1 used in the process of step S2 to prevent hunting. If the determination result shows that the rotational oil pressure of the taphole drilling machine 1 is equal to or greater than the set value P1 (step S5: Yes), the control device returns the drilling process to the process of step S3. On the other hand, if the rotational oil pressure of the taphole drilling machine 1 is less than the set value P1 (step S5: No), the control device advances the drilling process to step S6.

[0021] In the process of step S6, the control device advances the drill rod 2 of the taphole drilling machine 1. Thereafter, the control device repeatedly executes a series of drilling processes until the taphole is drilled.

[0022] As is clear from the above description, in the drilling process according to one embodiment of the present invention, the control device detects the rotational oil pressure during taphole drilling, and if the detected rotational oil pressure is equal to or greater than a predetermined value, determines that there is a high possibility of lateral perforation. This makes it possible to predict whether lateral perforation will occur during taphole drilling. Furthermore, if it is determined that there is a high possibility of lateral perforation, the rate of lateral perforation can be reduced by stopping the feed of the drill rod or retracting the drill rod.

[0023] Although the present invention has been described above as an embodiment, the present invention is not limited to the descriptions and drawings that form part of the disclosure of the present invention. In other words, other embodiments, examples, and operational techniques that can be made by those skilled in the art based on the present invention are all included in the scope of the present invention. [Explanation of symbols]

[0024] 1 Tap hole drilling machine 2 drill rods

Claims

1. A method for predicting whether a lateral hole will occur when drilling a taphole of a blast furnace using a hydraulically driven taphole drilling machine that drills a taphole by combining functions of feeding, rotating, and striking a drill rod, comprising: a detection step of detecting rotational oil pressure when the taphole is being opened; a determining step of determining that there is a high possibility of the lateral hole occurring when the rotational oil pressure detected in the detecting step is equal to or greater than a predetermined value; A method for predicting the occurrence of a lateral hole, comprising:

2. 2. The method for predicting the occurrence of a lateral hole according to claim 1, wherein the determination step includes a step of determining that the occurrence of the lateral hole is highly likely when the rotational oil pressure detected in the detection step is equal to or greater than a predetermined value and the amount of change in the hole depth is equal to or less than a second predetermined value.

3. 3. A method for controlling a taphole drilling machine, comprising the step of stopping the feeding of the drill rod or retracting the drill rod when it is determined that there is a high possibility of the lateral hole occurring by the lateral hole occurrence prediction method according to claim 1 or 2.

4. A method for operating a blast furnace, comprising the step of stopping the feeding of the drill rod or retracting the drill rod when it is determined that there is a high possibility of the lateral hole occurring by the lateral hole occurrence prediction method according to claim 1 or 2.

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