JP2010007178A - Method for grasping charging situation of raw materials in bell-less blast furnace, and method for operating blast furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for grasping the charging situation of raw materials by which, in a bell-less blast furnace, the relation between the laying order in a conveyer and the discharging order of the raw materials from a furnace top bunker, etc., can be grasped. <P>SOLUTION: In the method for grasping the charging situation of the raw materials in the bell-less blast furnace having distributing chutes at the furnace top part of the blast furnace, RFID (Radio Frequency Identification) tags which are different in ID information, are set on each raw material in the conveyer for conveying the raw material to the blast furnace and the ID information of the RFID tag discharged from the furnace top bunker, is detected by a lower part tag detecting mechanism in which a lower part ID information detecting end part is disposed at the discharging hole or the lower part of the furnace top bunker, and the charging situation of the raw material is grasped by using the arranging order of the RFID tag on the conveyer and the discharging order from the bunker in the RFID tag detected by the lower part tag detecting mechanism. Thus, this result is used, and the optimization of the raw material distribution is achieved and the proper operation of the blast furnace can be obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for grasping a raw material charging state into a blast furnace having a bellless charging device (hereinafter also referred to as a “bellless blast furnace”) and a method for operating the blast furnace. The present invention relates to a method for grasping a raw material charging state in a bell-less blast furnace that can be improved, and a method for operating a blast furnace using the raw material charging state grasping method.

  In general, in blast furnace operation, ores such as lump ore, sintered ore, and pellets, which are raw materials, and coke are alternately charged and deposited in layers from the top of the blast furnace. The hot air blown from the tuyeres of the blast furnace gasifies and extinguishes the coke deposited in the lower part of the blast furnace, and when the ore melts and drops, the raw material in the blast furnace descends and the layer height increases. Will decline. Therefore, ore and coke are alternately charged from the top of the furnace so that the bed height is always maintained at a substantially constant height.

  FIG. 1 is a diagram showing a configuration of a conventional bellless blast furnace and an apparatus for charging raw materials into the bellless blast furnace. The raw material charging in the bell-less blast furnace will be described with reference to FIG. A tilting angle (an angle formed by the longitudinal axis of the chute and the vertical line) can be changed at the upper part of the blast furnace 10, and a distribution chute 12 that turns is provided. In the upper part of the blast furnace 10, a collecting hopper 13, a furnace top bunker 14, and a raw material charging portion 15 are provided in order from the side closer to the furnace body of the blast furnace 10. Two furnace top bunkers 14 are usually juxtaposed above the collecting hopper 13, but three may be juxtaposed or arranged in two vertical stages. The end of the conveyor 16 (end on the downstream side in the transport direction) is disposed above the raw material charging unit 15, and the ore is located above the other end (end on the upstream side in the transport direction) of the conveyor 16. A raw material tank 17 in which 21 or coke 23 (hereinafter collectively referred to as “raw material 20”) is stored for each type is disposed. Hereinafter, the furnace top bunker and the distribution chute are also simply referred to as “bunker” and “chute”, respectively.

  The raw material 20 discharged from the raw material tank 17 onto the conveyor 16 according to a predetermined charging amount is conveyed to the upper part of the raw material charging unit 15 by the conveyor 16. The conveyed raw material 20 falls into the raw material charging unit 15, temporarily stored in the furnace top bunker 14, and then charged into the blast furnace 10 through the collecting hopper 13 and the distribution chute 12.

  Normally, when charging the raw material 20 into the blast furnace 10, the ore 21 and coke 23 are not charged all at once, but the ore 21 and coke 23 are alternately passed through the top bunker 14 several times. Divided and charged. This division unit of the raw material 20 is referred to as a batch. In the bell-less blast furnace, the tilt angle of the distribution chute 12 is changed during the charging of one batch to change the charging position of the raw material 20 into the blast furnace 10.

  In today's blast furnace operation, it is important to ensure both the air permeability in the furnace and the improvement of the reaction efficiency because of the improvement of production efficiency, resource saving and global environmental problems. In order to ensure air permeability and improve reaction efficiency, it is effective to appropriately control the deposition state of the raw material in the radial direction in the blast furnace, that is, the distribution of charges in the blast furnace.

  As a method for controlling the distribution of charges in the blast furnace, in addition to the change in the tilt angle of the distribution chute described above, the following methods are used in combination as appropriate. As the method, the particle size of the raw material charged into the blast furnace is not always made uniform so as to always have an average particle size, but the method of appropriately controlling the change with time, or coke is mixed appropriately. A method of charging the ore layer at an appropriate radial position in the blast furnace can be mentioned. In general, in blast furnace operation, the larger the particle size of the raw material charged in the center of the furnace, the more advantageous it is to ensure air permeability, the operation is stable, and there is coke in the ore layer. This is based on the knowledge that the reduction reaction of ore is promoted.

  As described above, when discharging the raw material from the raw material tank onto the conveyor, the particle size and type of the raw material, and the mixing ratio of the ore and coke are changed in time series for controlling the distribution of the charge. Is traditionally taken. However, it is known that the order of the raw materials loaded on the conveyor does not necessarily match the order of the raw materials discharged from the bunker and charged into the blast furnace. The reason is considered as follows.

  First, when a raw material is charged from a conveyor into a bunker, a raw material having a small particle size, such as a raw material having a large particle size or coke in a mixture of ore and coke, is caused by particle size segregation or density segregation. Deposits on the outer periphery (side wall). When the charged raw material is discharged from the bunker, since the raw material is a granular material, the flow speed is fast immediately above the bunker discharge port, and the flow speed is slow near the side wall. "Occurs.

  Therefore, due to this particle size segregation, density segregation, and funnel flow, a relatively small particle size raw material deposited directly above the bunker outlet or a high density material has a relatively small particle size deposited on the outer periphery of the bunker. It tends to be discharged earlier than large raw materials or raw materials with low density.

  Therefore, in the bell-less blast furnace, controlling the charging of the raw material into the bunker so that the target specific raw material is discharged from the bunker at the target timing is necessary for controlling the distribution of the raw material in the furnace. It is both an important and difficult task.

  As a method for obtaining a guideline of a raw material charging method for controlling the distribution of raw materials in a furnace, for example, Non-Patent Document 1 discloses that microwaves are emitted to particles such as falling sintered ore or coke. Thus, a method for measuring the particle size by the scattered power from the particles is disclosed.

  In Patent Document 1, an electromagnetic wave having a wavelength close to the particle size of the granular object is incident on the surface of the granular object made of ore or coke charged in the blast furnace at a predetermined incident angle. A method of estimating the granularity of a granular object by obtaining a reflection angle at which the intensity is maximum among the reflected waves reflected from the surface of the granular object is disclosed.

  Further, in Patent Document 2, a hollow coil to which an alternating current is applied is arranged below the bunker top bunker so that the raw material dropped into the blast furnace passes through the inside, and the passage of the raw material is performed. A method for measuring the mixing ratio of raw materials charged into a blast furnace based on an output voltage sometimes generated in a coil is disclosed.

JP-A-5-52737 (Claims and paragraphs [0014] to [0022]) JP 2007-155570 A (claims, paragraphs [0023] and [0024] and FIG. 6)

Yoshiyuki Shirakawa, 4 others, “Development and commercialization of on-line particle size measurement technology using microwaves”, Steel Research, Nippon Steel Corporation, 1990, No. 339, p. 8-13

  However, the methods described in any of the documents are directly related to the loading order of the raw materials on the conveyor, the order of the raw materials discharged from the bunker, the particle size, and the change over time of the mixing ratio of ore and coke in the raw materials. It is not possible to determine a proper correspondence.

  If the order and particle size of the raw material discharged from the bunker and the mixing ratio of ore and coke in the raw material are known, it can be estimated from which position the raw material is charged in the blast furnace from the relationship with the angle of the chute. Based on this, it is possible to optimize the operating conditions of the blast furnace. Therefore, it is required to understand the relationship between the loading conditions of raw materials such as the order of loading on the conveyor into the blast furnace and the order and particle size of the raw materials discharged from the bunker, and the temporal change in the mixing ratio of ore and coke. ing. However, as described above, it has been difficult for the conventional technology to grasp these relationships. For this reason, it has been difficult to optimize the operating conditions of the blast furnace as described above.

  The present invention has been made in view of the above problems, and in order to optimize the operating conditions of the blast furnace, the loading order of the raw materials on the charging conveyor, the order and the particle size of the raw materials discharged from the furnace top bunker The purpose is to accurately grasp the relationship between the change in the mixing ratio of ore and coke and to control the order of the raw materials loaded on the conveyor and the order of the raw materials discharged from the furnace bunker based on the results. .

  In recent years, an authentication (recognition) technique using non-contact communication using radio waves and an IC chip, which is called RFID (Radio Frequency Identification), is gradually spreading.

  By using RFID, an IC chip with an antenna processed into a tag or a label (RFID tag, hereinafter also simply referred to as “tag”) is given to a person or an object, and information (ID information, hereinafter) stored individually in the tag By simply reading “ID”) with a device called a tag reader, personal authentication or object recognition can be performed. Since RFID uses non-contact communication by radio waves, it is superior in that it is resistant to dirt and can be recognized and authenticated away from the target as compared with conventional ID recognition by bar code.

  There are two types of RFID tags, a passive method and an active method. Passive tags operate using radio waves (UHF band and microwave band) from a tag reader as an energy source, and do not need to have a built-in battery, so they are small and inexpensive. The ID information of the passive tag is carried by radio waves (reflected waves) in which a tag antenna reflects a part of radio waves from the tag reader. Since the intensity of the reflected wave is very small, the reception distance is shorter than that of the active method described later, and the tag reader receives and decodes a very weak reflected wave from the tag. Must be supplied. Moreover, in order to use the radio waves, it is necessary to apply to a radio station in accordance with the Radio Law. However, it has the merit of being small and inexpensive and operating almost permanently, and can be applied to continuous monitoring in actual operation.

  On the other hand, an active tag operates using a built-in battery as an energy source, and the tag itself emits radio waves. Therefore, there is a merit that the communication distance can be as long as 10 to 100 m, and the radio wave does not require an application by the Radio Law in the normal use range. However, there is a disadvantage that the tag is expensive.

  In order to solve the above-mentioned problems, the present inventors have studied using this RFID tag. As a result, RFID tags with different IDs are placed or mixed in the raw material loaded on the conveyor as a tracer, and detected after the outlet of the bunker top bunker to load the raw material on the conveyor It was found that it becomes possible to associate the order with the order discharged from the bunker. That is, it has been found that it is possible to easily determine the raw material stacking order on the conveyor, which can obtain the intended furnace interior inclusion distribution.

  The present invention has been made on the basis of the above-mentioned knowledge, and the gist thereof is a method of grasping the raw material charging state in the bellless blast furnace described below and a method of operating the bellless blast furnace based on the grasped result.

  In the method of grasping the raw material charging status in a bell-less blast furnace having a distribution chute at the top of the blast furnace, RFID tags having different ID information are arranged in the raw material on the conveyor that conveys the raw material to the blast furnace and discharged from the top bunker. ID information of the RFID tag is detected by a lower tag detection mechanism in which a lower ID information detection end is disposed below the discharge port of the furnace top bunker, and the arrangement order of the RFID tags on the conveyor, and the lower tag A method for grasping a raw material charging state in a bell-less blast furnace, wherein the raw material charging state is grasped using a discharge order of the RFID tag detected from the bunker by a detection mechanism.

  In the present invention, “ID information” is information consisting of an array of characters such as letters and numbers stored individually in the RFID tag, and in the case of only numbers, it is also referred to as “ID number”. The “raw material charging status” means the charging order of raw materials and the mixing ratio of ore and coke. The “tag detection mechanism” includes an ID information detection end and an RFID tag reader.

  In the method of grasping the raw material charging status in the bell-less blast furnace, when RFID tags are arranged in the order of pre-recorded ID information on the raw material on the conveyor discharged in one batch from the furnace bunker, the RFID tag on the conveyor This eliminates the need for providing a tag detection mechanism for detecting the arrangement order in the apparatus, which is preferable in terms of device management and cost reduction. In addition, it is preferable to arrange the RFID tags at equal intervals on the raw material on the conveyor because it is possible to obtain unbiased information about the raw material charging status.

  Before discharging the raw material onto the conveyor, the RFID tag is mixed into the raw material stored in the raw material tank, and the arrangement order of the RFID tag on the conveyor is loaded into the furnace bunker from the conveyor together with the raw material. In this case, the detection may be performed by the upper tag detection mechanism in which the upper ID information detection end is disposed above or in the charging section of the furnace top bunker. In this case, it is not necessary to manage RFID tags in the order of ID information before arrangement.

  The raw material has a particle size distribution width, and the RFID tag is formed in a plurality of types of particle sizes within the particle size distribution width, and the ID information includes the information on the particle size. It becomes possible to grasp the time change for each particle size of the discharged amount, that is, the time change of the particle size.

  The raw material is composed of a plurality of types of raw materials, and the RFID tag ID information includes information on the type of each raw material, and an RFID tag is arranged on the conveyor corresponding to the raw material type information included in the ID information. By doing so, it becomes possible to grasp the charging status of each raw material, that is, the charging order and mixing ratio of each raw material. If the density of multiple types of raw materials is different, the behavior of each raw material can be tracked more accurately by coating the RFID tag with a substance having a density that is the same as or close to that of the raw material of each density, and the mixing ratio Can be grasped.

  In addition, by using the above method, it is possible to accurately grasp the relationship between the loading order of the raw materials on the conveyor, the order and particle size of the raw materials discharged from the top bunker, and the temporal change in the mixing ratio of ore and coke. Therefore, based on the grasped result, it is possible to control these operation amounts and optimize the operating conditions of the blast furnace.

  According to the present invention, based on the above grasped result, by appropriately optimizing the blast furnace charge distribution conditions, the blast furnace's air permeability and reaction efficiency are improved, stable operation of the blast furnace, and account for the raw material. It is possible to contribute to the operation of a low reducing material ratio that reduces the ratio of the reducing material.

It is a figure which shows the structure of the apparatus which inserts a raw material into the upper part of the conventional bell-less blast furnace, and a bell-less blast furnace. It is a figure which shows the structural example of the raw material charging apparatus using the grasping | ascertaining method of the raw material charging condition which concerns on the 1st Embodiment of this invention. It is a figure which shows the structural example of the raw material charging apparatus using the grasping | ascertaining method of the raw material charging condition which concerns on the 2nd Embodiment of this invention. It is a figure which shows the arrangement | positioning conditions of the raw material in the furnace top bunker used for the numerical simulation. It is a graph which shows the bunker discharge | emission behavior of a raw material of interest, The figure (a) is a graph about cases 1-4 and the figure (b) is a graph about cases 5-7. It is a graph which shows the furnace top charge distribution of a raw material of interest, and the same figure (a) is a graph about cases 1-4 and (b) is about cases 5-7. It is a figure which shows the test method and test result in Example 1, The figure (a) is a schematic diagram which shows the charging and discharging order to the furnace top bunker of the ore tag arrange | positioned on the conveyor, (b) Is a graph showing the detection results. It is a graph which shows the detection number according to the particle size of the ore tag discharged | emitted from the bunker. It is a figure which shows the structural example of the raw material charging device used for Example 2. FIG. It is a figure which shows the test method and test result in Example 2, the figure (a) is a schematic diagram which shows the structure of the raw material row | line for examination of Example 2, (b) is the ore tag discharged | emitted from the bunker It is a graph which shows the number of detection according to particle size. It is a figure which shows the test method after the improvement in Example 2, and a test result, The figure (a) is a schematic diagram which shows the structure of the raw material row | line after the improvement of Example 2, (b) is discharged | emitted from a bunker. It is a graph which shows the detected number according to the particle size of the ore tag. It is a block diagram of the experimental apparatus used for the measurement experiment of the bunker discharge | emission timing of the attention raw material of Example 3. FIG. 6 is a graph of detection timing of an RFID tag of a raw material of interest in Example 3.

  As described above, the method for grasping the raw material charging state of the present invention is as described above, in the raw material charging state in the bellless blast furnace having a distribution chute at the top of the blast furnace furnace, An RFID tag with different ID information is arranged, and the ID information of the RFID tag discharged from the furnace top bunker is detected by a lower tag detection mechanism in which a lower ID information detection end is arranged at the outlet of the furnace top bunker or below the outlet. The charging status of the raw material is grasped by using the arrangement order of the RFID tags on the conveyor and the discharge order of the RFID tags detected by the lower tag detection mechanism from the bunker. It is a method of grasping the raw material charging situation in the bell-less blast furnace.

1. First Embodiment FIG. 2 is a diagram illustrating a configuration example of a raw material charging apparatus using a method for grasping a raw material charging state according to a first embodiment of the present invention. The raw material charging apparatus shown in FIG. 2 is the same as that shown in FIG. 1 except that a tag mixing machine is arranged.

  In the raw material charging apparatus shown in FIG. 2, two tag mixing machines 18 are arranged on the downstream side of the raw material tank 17 at the upper end of the conveyor 16 on the upstream side in the transport direction. The tag mixing machine 18 accommodates an RFID tag 40 (a general term for ore tags 41 and 42 having two kinds of sizes described later and a coke tag).

  Further, the ID number transmitted from the RFID tag 40 mixed in the raw material 20 to the ceiling inside the collecting hopper 13 (the portion above the collecting hopper 13 and excluding the connecting portion with the piping of the furnace bunker 14). A lower ID information detection end (lower detection antenna) 32 for detecting a signal including a signal is disposed. A tag reader 31 is connected to the detection antenna 32, and the ID number of the detected RFID tag 40 and the time when the signal is detected are recorded in the tag reader 31. Here, the ID information detection end and the tag reader (detection antenna) are collectively referred to as a “tag detection mechanism”.

  The raw material 20 including the RFID tag 40 discharged from the furnace top bunker 14 is exposed together with the RFID tag 40 above the dropping port discharged to the distribution chute 12 below the collecting hopper 13. For this reason, the signal of the RFID tag 40 can be stably detected by the lower detection antenna 32.

  The RFID tag 40 is dropped and placed by the tag mixer 18 on the row of the raw materials 20 discharged from the raw material tank 17 and conveyed by the conveyor 16. Here, the required number of RFID tags 40 is placed at a required position for the row of raw materials 20 on the conveyor 16 discharged from the furnace top bunker 14 in one batch.

  The signal of the RFID tag 40 discharged from the tag mixing machine 18 is detected by a detection antenna provided at or near the discharge port of the tag mixing machine 18, and the time when the signal of each RFID tag 40 is detected is It is recorded together with the ID number in the lower tag reader 31 connected to the detection antenna 32. From this record, the order and position of the RFID tag 40 on the raw material 20 can be grasped.

  The RFID tag 40 is conveyed together with the raw material 20 to the upper portion of the raw material charging unit 15 by the conveyor 16, falls into the raw material charging unit 15, and is temporarily stored in the furnace top bunker 14. Then, a signal is detected by the lower detection antenna 32 when being discharged from the furnace top bunker 14 to the collecting hopper 13. Thereafter, the hopper 10 is charged from the collecting hopper 13 through the distribution chute 12. Thereby, the arrangement | sequence order of the raw material 20 on the conveyor 16 and the discharge | emission order from the collection hopper 13 can be linked | related, ie, the behavior of the raw material 20 can be tracked.

  The arrangement of the RFID tags 40 on the raw material 20 is preferably equidistant. By setting the arrangements at equal intervals, it is possible to obtain unbiased information on the behavior of the raw material 20 at each position on the conveyor 16.

  And based on this tracking result, the raw material arrangement | sequence on the conveyor 16 of the raw material 20 discharged | emitted from the raw material tank 17 so that arrangement | positioning of the raw material charged in the blast furnace 10 may become appropriate for stabilization of blast furnace operation. It is also possible to control the conveying speed of the conveyor 16 and the tilt angle of the distribution chute 12.

1-1. Form of RFID Tag An example of the form of an RFID tag that can be used in the method for grasping the raw material charging state according to the present invention will be described. As the RFID tag, either an active method or a passive method can be used. In the case of an active tag, it has a button shape of about 20 mm square, has a battery inside, and transmits a signal including an ID number unique to the tag at intervals of 0.2 seconds. The heat-resistant temperature of the RFID tag is 80 ° C., which is the upper limit of battery operation, but since the ambient temperature below the bunker where signals are detected is 80 ° C. or lower, the RFID tag can be operated without problems. The passive tag is smaller than the active tag and does not have a built-in battery. Therefore, the heat-resistant temperature is higher than that of the active tag, and in this case, it can be operated without any problem.

  The RFID tag may be mixed in the raw material in an exposed state, but may be embedded in a resin or inserted into the raw material as described below. For example, an RFID tag (hereinafter also referred to as “coke tag”) to be mixed with coke out of raw materials is manufactured by embedding in a plastic resin block of a predetermined size having the same or similar density as coke. can do. Accordingly, since the signal can be received even when the RFID tag is in the coke having conductivity, the behavior of the coke having the predetermined size can be accurately tracked.

  As the plastic resin, a polyacetal resin having a heat-resistant temperature of 150 ° C. sufficient for carrying out the present invention and capable of easily transmitting radio waves can be used. As for the size of the resin lump, for example, when using medium lump coke as the coke, a resin having a diameter of about 30 mm is prepared in accordance with the particle size. What is necessary is just to produce a thing about 50 mm in diameter which is a particle size contained in the width | variety, and 80 mm.

  In addition, an RFID tag (hereinafter referred to as “ore tag”) to be mixed in ore can be produced by making a hole in the ore and inserting it into the ore. Since the ore is an insulator and transmits radio waves well, it is possible to accurately track the behavior of the ore and the ore of a similar particle size around the ore by using the ore tag. As the size of the ore into which the RFID tag is inserted, for example, a diameter of about 30 mm or about 50 mm can be given as a typical particle size.

  In this way, by burying the RFID tag in a resin or inserting it in ore, it is possible to ensure durability that is unlikely to fail even if mixed in a large amount of raw material on a conveyor or in a hopper. Further, by placing each type of RFID tag on a corresponding type of raw material on a conveyor, the behavior of the raw material can be tracked for each type and size.

  When using RFID tags having a plurality of sizes, the behavior of each size particle can be tracked with high accuracy by arranging the RFID tags having the same size at the same position.

  Management is facilitated by setting the ID number of the RFID tag so that the type and size of the raw material at the position to be placed can be known in addition to the unique identification number. For example, among the eight digits constituting the ID number, the leftmost digit can be a raw material type, the second digit from the left can be the size of the raw material, and the remaining six digits can be a unique identification number.

1-2. Detection antenna of tag detection mechanism A dipole antenna can be used as the detection antenna of the tag detection mechanism. A dipole antenna can detect an ID number signal even from an RFID tag about 20 m away under the condition that there is no shielding object, and the depth is within 10 cm even when buried in a coke layer as a conductor. Then, it is possible to detect a stable signal through a slight gap between coke particles. Moreover, if the installation space of a detection antenna permits, the Yagi antenna etc. with a detection sensitivity higher than a dipole antenna can also be used.

2. Second Embodiment The arrangement of RFID tags on the raw material on the conveyor is not limited to the method of dropping and placing from the tag mixing machine on the raw material row on the conveyor, but by the method of premixing the raw material in the raw material tank. It doesn't matter.

  FIG. 3 is a diagram illustrating a configuration example of the raw material charging apparatus using the raw material charging state grasping method according to the second embodiment of the present invention. In the raw material charging apparatus shown in FIG. 3, since the ore tag or the coke tag is charged in the raw material tank, there is no tag mixing machine, and there are two tag readers and two detection antennas, that is, a tag detection mechanism. The configuration is the same as that of the raw material charging apparatus shown in FIG.

  In the present embodiment, as shown in FIG. 3, the upper detection antenna 34 connected to the upper tag reader 33 is mounted on the ceiling inside the raw material charging unit 15 (the upper part of the raw material charging unit 15 and is loaded from the conveyor 16. The lower detection antenna 32 connected to the lower tag reader 31 is arranged on the ceiling inside the collecting hopper 13. Since both the upper detection antenna 34 and the lower detection antenna 32 can directly capture a signal including an ID number transmitted from the RFID tag 40, the signal can be stably received from the RFID tag 40. Each of the upper tag reader 33 and the lower tag reader 31 records the ID number of the detected ore tag or coke tag and the time when the signal was detected.

  The raw material 20 in the raw material tank 17 stored for each type of ore 21 and coke 23 is mixed with an RFID tag 40 set with an ID number that can identify the type of the raw material 20 in addition to the unique identification number. And the RFID tag 40 are discharged onto the conveyor 16 together.

  When the RFID tag 40 conveyed by the conveyor 16 together with the raw material 20 is inserted into the furnace top bunker 14, a signal is detected by the upper detection antenna 34 disposed in the raw material charging unit 15, and the ID number and detection time are detected. Is recorded in the upper tag reader 33. From the record of the upper tag reader 33 obtained in this way, the arrangement order of the RFID tag 40 mixed in the raw material 20 on the conveyor, its position and interval can be calculated.

  Subsequently, when the raw material 20 is discharged from the furnace top bunker 14 into the blast furnace 10, the RFID tag 40 detects a signal by the lower detection antenna 32 disposed in the collecting hopper 13, and the ID number and the detection time are determined by the lower tag reader. 31.

  Therefore, the correlation between the order of the raw materials 20 on the conveyor 16 and the order of discharge from the furnace top bunker 14 can be obtained based on the data about each RFID tag 40 recorded in the upper tag reader 33 and the lower tag reader 31. it can. As a result, detailed and specific data can be obtained regarding the influence of the segregation of the raw material and the funnel flow in the furnace top bunker 14, which has conventionally been limited to understanding the sensory outline.

  In addition, by comparing the results of the above correlation over a long period of time, the discharge characteristics and descending behavior of the material in the bunker due to wear of the bunker inner wall and bunker equipment due to the collision of the material charged into the bunker It is possible to grasp changes in mechanical properties such as Moreover, the order for every kind of the raw material 20 on the conveyor 16 can be changed, and the discharge | emission order from the furnace top bunker 15 of the raw material 20 can be optimized.

  When the RFID tag 40 is mixed in the raw material 20 in the raw material tank 17 in advance, it is desirable that the number of RFID tags 40 per one raw material tank is larger. However, in normal operation, the amount of the RFID tag 40 is about 100 t relative to the raw material 100t in the raw material tank. If about 50, that is, about 0.5 per 1 ton of raw materials are mixed, the correlation of the discharge order of the raw materials can be obtained with sufficient accuracy.

  In addition, if the RFID tag 40 is uniformly mixed in the raw material 20 at all times, the charging state of the raw material 20 into the blast furnace 10 can be monitored at all times. As a result, it is possible to immediately detect an abnormality caused by failure to load the raw material as intended.

  By using the method for grasping the raw material charging status, it is possible to take measures such as changing the order of the types of raw materials 20 on the conveyor 16 and to ensure stable operation of the blast furnace. The inventors confirmed this by simulation using a mathematical model.

  In a bell-less blast furnace, when the target material is charged simultaneously with other raw materials in the same batch, if the discharge period of the target material from the top bunker is shorter than the discharge period from the top bunker, It is estimated that the raw material of interest in the center is concentrated in a specific part. Conversely, the closer the discharge period of the target material from the furnace top bunker is to the discharge period of the entire material from the furnace top bunker, it is expected that the raw material will be mixed and charged with other raw materials in a wider range.

  The inventors conducted a numerical simulation to determine the relationship between the ratio (τ = t2 / t1) of the target material bunker discharge period (t2) to the discharge period (t1) of all the raw materials from the top bunker and the deposition position of the target material in the furnace. Arranged. When the discharge period of the material of interest appears in a divided manner, the ratio (τ) of the bunker discharge period of the material of interest is defined with the total of the discharge periods as t1.

  FIG. 4 is a view showing the arrangement conditions of the raw materials in the furnace top bunker used for the numerical simulation. The calculation conditions for this numerical simulation are shown in FIG. 4 and Tables 1 and 2.

As shown in FIG. 4, raw materials W ₁ , W _2, and W ₃ are sequentially charged and stored in the furnace top bunker 14. The raw material W ₁ and the raw material W ₃ are sintered ore, and the raw material W ₂ is a medium mass coke.

In this numerical simulation, the total mass of all the raw materials was 123.1 t, and the raw material W ₂ was the raw material of interest. As shown in Table 1, in Cases 1 to 7, the raw material W _{2 as} the raw material of interest was constant at 3.1 t, and the raw materials W ₁ and W ₂ were distributed so that the total was 120 t. In case 1, the raw material W ₁ was not charged, and only the raw material W ₂ and the raw material W ₃ were charged. In case 7, the raw material W ₃ was not charged, and only the raw material W ₁ and the raw material W ₂ were charged. Table 2 shows the tilt angle and the number of turns of the chute as charging conditions for the ore batch (raw materials W _{1 to} W ₃ ). The raw material was charged while controlling the tilt of the chute from the low tilt angle side to the high tilt angle side. At each tilt angle, the raw materials were charged at the number of turns as shown in Table 2, and the charging of all the raw materials was completed at the final turn of the maximum tilt angle at which the number of turns was not zero.

  The results of the calculation are shown in FIGS.

  Table 3 shows the ratio (τ) and evaluation of the bunker discharge period of the raw material of interest for cases 1 to 7. The evaluation is performed with respect to the radial deviation of the amount of the target raw material deposited at the top of the blast furnace layer. The x in the evaluation column indicates that the deviation is equal to or greater than a predetermined value, and the circle indicates that it is less than the predetermined value.

  FIG. 5 is a graph showing the bunker discharge behavior of the raw material of interest, where (a) is a graph for cases 1 to 4 and (b) is a graph for cases 5 to 7. In FIG. 5, the horizontal axis represents the bunker discharge dimensionless time, that is, the discharge time from the bunker of the raw material, where the discharge period from the top bunker of all raw materials is 1, and the vertical axis represents the bunker discharge speed of the target raw material, that is, the unit It was set as the mass of the raw material of interest discharged per hour.

  FIG. 6 is a graph showing the furnace top charge distribution of the raw material of interest, where (a) is a graph for cases 1 to 4 and (b) is a graph for cases 5 to 7. In FIG. 6, the horizontal axis is the distance from the center of the blast furnace where the topless dimension radius of the blast furnace layer, that is, the furnace port radius in the blast furnace is 1, and the vertical axis is the target raw material layer deposition amount, that is, the unit of the target raw material deposited. The mass per area was taken.

  From the viewpoint of improving reaction efficiency and air permeability in the blast furnace, it is desirable that the deviation in the radial direction of the amount of raw material deposited at the top of the blast furnace layer is small. In FIG. 6, the peaks of the material deposition amount of interest are apparent in cases 1 and 2 near the dimensionless radius 0.4, and in cases 6 and 7 near the dimensionless radius 0.75. As in Cases 1, 2, 6, and 7, it is considered that the reaction efficiency and air permeability in the blast furnace decrease when the radial deviation of the amount of raw material of interest increases.

  In cases 1 and 2, from Table 3, the ratio (τ) of the bunker discharge period of the raw material of interest to the discharge period from the top bunker of all raw materials is 0.70 and 0.85, respectively. Therefore, it is estimated that when τ is less than 0.90, the radial deviation of the amount of material deposition of interest at the top of the blast furnace layer increases. Therefore, it is a necessary condition for charging the target raw material in a wide range to control the order of charging the target raw material into the bunker so that τ is 0.90 or more.

  However, as in Cases 6 and 7, even when τ is 0.90 or more, the radial deviation of the amount of material deposition of interest at the top of the blast furnace layer may increase. Therefore, in order to improve the accuracy, the inventors conducted a numerical simulation to determine the relationship between the time deviation of the frequency of discharge of the top bunker of the target material and the mixing state of the target material within the discharge period of the total material from the top bunker. Organized and shown in Table 4.

  As a result, as shown in Table 4, when the time deviation σ of the furnace top bunker discharge frequency of the material of interest exceeds 0.4, the material of interest is charged into a specific part at the top of the blast furnace layer, that is, at the top of the blast furnace layer. It was found that the radial deviation of the amount of accumulated raw material of interest increased. Here, the time deviation σ of the furnace top bunker discharge frequency of the material of interest is defined by the following equation (1). This σ is 0 when the raw material of interest is completely and temporally discharged within the discharge period of all the raw materials from the furnace top bunker, and increases as the temporal deviation increases. The description in the evaluation column of Table 4 is the same as that of Table 3.

  In actual blast furnace operation, it is not possible to directly grasp when the raw material of interest is discharged from the top bunker. Therefore, in the method of grasping the raw material charging state of the present invention, the RFID tag is used to grasp the discharge timing of the raw material of interest from the furnace bunker, and the blast furnace operating method of the present invention is carried out based on this grasped content. It is. The present invention is applicable even when the bunker shape, the size of the bunker, the type of raw material, and the like are different.

  When the RFID tag is used, the deviation σ can be calculated from the equation (2) in which the symbol of the equation (1) is replaced according to the correspondence table shown in Table 5.

  In order to confirm the effect of the method of grasping the raw material charging state in the bell-less blast furnace according to the present invention, the following tests were conducted. Examples 1 and 2 described below are part of a test study, and have a radio wave intensity and a frequency that can be used without notification, and can detect an ID signal stably from a position several meters away. From the viewpoint, an active method with a transmission frequency of 315 MHz was adopted as the RFID method.

<Example 1>
The Example implemented using the raw material charging apparatus shown in the said FIG. 2 is described.

  In Example 1, ore tags having a diameter of 30 mm and 50 mm and having two kinds of large and small particle diameters were dropped on the ore conveyed by the conveyor one by one and arranged at intervals of 1 m. The length of the ore row on the conveyor is 15m, and one ore tag is placed at the center of each part of the ore row divided every 1m. Therefore, 15 ÷ 1 × 2 = 30. There are a total of 30 ore tags placed in.

  The ID number of the RFID tag inserted in the ore tag was set so that the size of the ore particle could be identified in addition to the unique identification number. And the signal containing ID number was detected from the ore tag mixed with the ore conveyed by the conveyor and discharged | emitted from the furnace top bunker to the hopper.

  FIG. 7 is a diagram showing test methods and test results. FIG. 7A is a schematic diagram showing in what order the ore tags arranged on the conveyor 16 are loaded into the furnace top bunker 14 and discharged. In FIG. 5A, a 15-meter ore row is divided into three equal parts, a leading part a, an intermediate part b, and a rear part c, and how these parts are loaded in the furnace top bunker is shown. The top part a, the middle part b, and the rear part c each contain five ore, a total of ten ore tags.

  In FIG. 7B, the horizontal axis indicates a dimensionless time, where the time from the start of the discharge of the ore from the furnace top bunker to the completion is 1, and the vertical axis indicates the frequency of detection of the ore tag at the bunker discharge port (arbitrary It is the graph which showed the time-dependent change taking a unit. As shown in the figure (b), at the very beginning of the discharge of ore, the ore tag arranged at the head part a is detected, and then the ore tag arranged at the intermediate part b and the rear part c is detected, In the latter half of the discharge, many were again located at the top. From this, regarding the discharge behavior of ore, a small amount of ore in the leading part a of the ore row is discharged at the initial stage of discharge from the bunker, and then only the ore in the intermediate part b and the rear part c is discharged, and in the latter part of the discharge In addition to the ore of the part b and the back part c, it turned out that much ore of the head part a was discharged | emitted.

  FIG. 8 is a graph showing the change over time in the number of detected ore tags by particle size discharged from the bunker. The horizontal axis represents the time from the start of discharging the ore from the furnace top bunker, and the vertical axis represents The number of detections every 10 seconds is taken. As shown in the figure, many small-diameter ore tags were detected in the early stage of ore discharge, and many large-diameter ore tags were detected in the late stage of discharge. From this, it was found that the small diameter ore was discharged before the large diameter ore. As described above, the particle size change over time of the discharged ore is different from the deposition behavior in the furnace top bunker depending on the particle size even if the arrangement on the conveyor is the same, and FIG. This is thought to be caused by the superposition of the discharge behavior shown in Fig. 1.

  In general, blast furnace operation is more stable because the larger the particle size of the raw material charged in the center of the furnace, the more stable the central gas flow is secured. Therefore, a test using such an ore tag is performed, and based on the result, by placing the raw material for each particle size on the conveyor, the particle size of the raw material charged in the center of the furnace is increased, The operation of the blast furnace can be stabilized. In addition, by controlling the particle size segregation influencing factors in the bunker, for example, the feed speed of the conveyor, the raw material falling position in the bunker, etc. so that the gradient of the particle size aging of the ore discharged from the bunker becomes large, The particle size of the raw material charged in the center of the furnace can be increased.

<Example 2>
An embodiment in which the arrangement order of the raw materials on the conveyor and the discharge order of the raw materials from the bunker is investigated using the ore tag and the coke tag, and the arrangement of the raw materials on the conveyor based on the results will be described.

  FIG. 9 is a diagram illustrating a configuration example of the raw material charging apparatus used in the second embodiment. The raw material charging apparatus shown in FIG. 9 is different from the raw material shown in FIG. 2 except that the tag mixing machine 18 is different from the mixing machine for mixing the ore tag in addition to the mixing machine for mixing the coke tag. The configuration is similar to that of the charging device.

  FIG. 10 is a diagram showing the test method and test results of this example. FIG. 10A is a schematic diagram showing a configuration of a raw material row for examination of this example. FIG. 5B is a graph showing the change over time in the number of detected ore tags and coke tags for each particle size. The horizontal axis represents the time from the start of ore discharge from the furnace top bunker. The axis is displayed as the number of detections every 10 seconds.

  In this example, first, a raw material row in which the first 5 m was a medium coke 23 and the remaining 10 m was an ore 21 was prepared for examination. A total of 10 coke tags 43 with a diameter of 30 mm are arranged on the row of medium mass coke 23 at intervals of 0.5 m, and a total of 10 types of large and small types with a diameter of 30 mm and 50 mm are placed on the row of ores 21. A total of 20 ore tags 41 and 42 having a particle size were arranged at 1 m intervals.

  The ID numbers of the RFID tags charged in the ore tags 41 and 42 and the coke tag 43 were set so that the type of ore or coke raw material and the size of the ore particles could be identified.

  And the ID signal was detected from the ore tag or coke tag mixed with the raw material conveyed by the conveyor and discharged | emitted from the furnace top bunker to the hopper.

  From FIG. 10 (b), it can be seen that the coke discharge time is divided into two periods, the raw material discharge initial stage and the final discharge period. This is due to the funnel flow of the raw material in the bunker.

  Based on this result, the arrangement of the raw material rows on the conveyor was examined and improved. In the improved raw material row, the ore row was divided and the order was changed, with the top 3 m being the ore 21, the middle 5 m being the medium mass coke 23, and the rear end 7 m being the ore 21. The arrangement of the ore tags 41 and 42 and the coke tag 43 on the ore 21 row and the coke 23 row was the same as in the case of the examination.

  FIG. 11 is a diagram illustrating a test method and a test result after improvement of the present example. FIG. 11 (a) is a schematic diagram showing the structure of the raw material row after the improvement of this embodiment, and FIG. 11 (b) shows the change over time in the number of detected ore tags by particle size discharged from the bunker. The vertical axis and the horizontal axis are the same as those in FIG.

  From FIG. 11 (b), it can be seen that by changing the arrangement of the raw materials on the conveyor, the ore and the coke are uniformly mixed and discharged over the entire discharge period of the raw material from the bunker.

<Example 3>
Using a 1/5 model of an actual machine, an experiment was performed in which the charging order of the target raw material in the raw material charged from the conveyor was changed and the bunker discharge timing of the target raw material by the RFID tag was measured.

FIG. 12 is a configuration diagram of an experimental apparatus used in the measurement experiment of the bunker discharge timing of the target material of Example 3. The experimental apparatus of FIG. 12 has substantially the same configuration as the raw material charging apparatus shown in FIG. 2 except that the dimensions and the raw material charging part are not provided, and substantially the same parts are denoted by the same reference numerals. is doing. The raw material W is charged into the furnace bunker 14 from the conveyor 16 in the order of the raw materials W ₁ , W ₂ and W ₃ . The raw material W ₁ and the raw material W ₃ are sintered ore, and the raw material W ₂ is a medium mass coke. In this experiment, the raw material W ₂ is used as a target raw material, and the coke tag 43 is mixed as an RFID tag (IC tag particles) only in the raw material W ₂ among the raw materials W.

The discharge amounts of the raw materials W _{1 to} W ₃ from the furnace top bunker 14 to the collecting hopper 13 are adjusted by a flow rate adjusting valve (FCG) 14a. The bunker discharge timing of the target raw material W ₂ is grasped by receiving the radio wave transmitted from the RFID tag by the IC tag receiver 31 through the antenna 32 installed on the upper portion of the collecting hopper 13 near the discharge port of the furnace top bunker 14. it can. An iron plate 13a is disposed at the upper end of the collective hopper 13 above the antenna 32 in order to avoid detection of an IC tag outside the apparatus that causes noise.

Table 6 shows the experimental conditions. In this embodiment, the total mass of all raw materials is 965 kg. As shown in Table 6, in Cases ₁ to 4, the raw material W _{2 as} the raw material of interest was fixed at 25 kg, and the raw materials W ₁ and W ₂ were distributed so that the total amount was 940 kg. That is, the charging order of the target raw material W ₂ in all the raw materials charged into the bunker from the charging conveyor was changed. In case 1, the raw material W ₁ was not charged, but only the raw material W ₂ and the raw material W ₃ were charged. The total number of RFID tags inserted was 30 and the number of time increments of the RFID tag detection frequency count was 10.

  The experimental results are shown in Table 6 and FIG. Table 6 shows the experimental condition and the ratio of the detection period of the target raw material (τ) to the discharge period of the entire raw material from the top bunker as the experimental result, and the top of the target raw material in the discharge period of the total raw material from the top bunker. The time deviation (σ) and evaluation of the bunker discharge frequency are shown. The evaluation is performed with respect to the radial deviation of the amount of the target raw material deposited at the top of the blast furnace layer. The x in the evaluation column indicates that the deviation is equal to or greater than a predetermined value, and the circle indicates that it is less than the predetermined value. In the present embodiment, the detection period of the RFID tag of the material of interest is the bunker discharge period t1 of the material of interest.

  FIG. 13 is a graph of the detection timing of the RFID tag of the material of interest in Example 3. FIG. 13 shows the bunker discharge timing of the RFID tag of the raw material of interest for each of cases 1 to 4, the horizontal axis indicates the bunker discharge dimensionless time, and the vertical axis indicates the IC tag detection frequency (pieces).

  As can be seen from the results for case 3 and case 4 shown in Table 6 and FIG. 13, by controlling the charging order of the raw materials from the charging conveyor to the bunker, the raw materials of interest for the discharge period from the top bunker of all the raw materials The detection period ratio (τ) of the raw material is controlled to 90% or more, and the time deviation (σ) of the discharge frequency of the top bunker of the material of interest within the discharge period from the top bunker of all raw materials is controlled to 0.4 or less. Can do. Therefore, if the numerical simulation results shown in Table 3 and Table 4 are taken into consideration, the raw material of interest is distributed over a wide range at the top of the blast furnace inner layer by controlling the charging order of the raw material of interest from the charging conveyor to the bunker. It can be done.

  According to the present invention, since the bunker discharge timing of the material of interest can be directly detected, even if the shape of the bunker, the material supply equipment to the bunker, and the material properties of interest are different, the loading order of the materials on the conveyor and the furnace top bunker It becomes possible to control the order of the raw materials discharged from the container with high accuracy.

  In this way, it is possible to optimize the arrangement of the raw material row on the conveyor by arranging the RFID tag on the raw material row conveyed on the conveyor and detecting the ID signal at the time of discharging from the furnace top bunker. Can contribute to the stabilization of blast furnace operation.

  According to the present invention, it is possible to accurately grasp the relationship between the loading order of the raw materials on the conveyor, the order and particle size of the raw materials discharged from the furnace bunker, and the temporal change in the mixing ratio of ore and coke. Based on the result, it is possible to control the amount of operation and to optimize the operating conditions of the blast furnace. Therefore, the method of the present invention enables accurate grasping of the raw material distribution in the furnace and highly accurate distribution control, and is widely applied as a raw material charging state grasping method for realizing good air permeability and reaction efficiency. it can.

10: blast furnace, 12: distribution chute, 13: collective hopper, 13a: iron plate,
14: Furnace top bunker, 14: Flow control valve (FCG), 15: Raw material charging section,
16: conveyor, 17: raw material tank, 18: tag mixing machine, 20: raw material, 21: ore,
23: Coke, 31: Lower tag reader,
32: Lower ID information detection end (lower detection antenna), 33: Upper tag reader,
34: Upper ID information detection end (upper detection antenna), 40: RFID tag,
41: Ore tag, 42: Ore tag, 43: Coke tag

Claims (8)

In the method of grasping the raw material charging status in the bell-less blast furnace having a distribution chute at the top of the blast furnace furnace,
RFID tags with different ID information are arranged in the raw material on the conveyor that conveys the raw material to the blast furnace, and the ID information of the RFID tag discharged from the furnace top bunker is the lower ID at the outlet of the furnace top bunker or below it. Detected by the lower tag detection mechanism provided with the information detection end,
A bell-less that grasps the charging state of the raw material by using the arrangement order of the RFID tags on the conveyor and the discharge order of the RFID tags detected by the lower tag detection mechanism from the bunker. Method of grasping the raw material charging status in the blast furnace.   In the bell-less blast furnace according to claim 1, wherein the RFID tags are arranged at equal intervals in the order of the ID information recorded in advance on the material on the conveyor discharged in one batch from the furnace top bunker. Method of grasping raw material charging status.   Before discharging the raw material onto the conveyor, the RFID tag is mixed into the raw material stored in the raw material tank, and the arrangement order of the RFID tag on the conveyor is changed from the conveyor together with the RFID tag to the furnace. In the bell-less blast furnace according to claim 1, wherein the top bunker is detected by an upper tag detection mechanism in which an upper ID information detection end is disposed above or at a charging portion of the top bunker. Method of grasping raw material charging status.   The raw material has a particle size distribution width, and the RFID tag is formed in a plurality of types of particle sizes within the particle size distribution width, and the ID information includes the particle size information. 4. A method for grasping a raw material charging state in a bell-less blast furnace according to any one of 3 above.   The raw material is composed of a plurality of types of raw materials, and information on the type of each raw material is included in the ID information of the RFID tag, and the RFID corresponding to the raw material type information included in the ID information on the conveyor A method for grasping a raw material charging state in a bell-less blast furnace according to any one of claims 1 to 4, wherein a tag is arranged.   6. The raw material charging situation in the bell-less blast furnace according to claim 5, wherein the plurality of types of raw materials have different densities, and the RFID tag is coated with a material having a density that is the same as or similar to the raw materials of the respective densities. How to figure out.   Using the method for grasping the raw material charging state according to any one of claims 1 to 6, the discharge timing of the raw material of interest from the furnace top bunker is detected by the RFID tag, and the total detection period of the RFID tags is all A method of operating a blast furnace, wherein the arrangement of the raw material of interest in the furnace top bunker is changed by changing the charging order so that the discharge period from the furnace top bunker is 90% or more. The operation method of the blast furnace according to claim 7, wherein the time deviation of the discharge frequency of the detected raw material from the top bunker defined by the following formula (1) is 0.4 or less. How to operate the blast furnace

Images