PALET MONITORING SYSTEM AND PALETLE MONITORING METHOD

Abstract

The invention relates to a pallet monitoring system capable of identifying a register that is likely to detach before the register actually detaches. The pallet monitoring system is for monitoring a sintering machine pallet, whose floor surface is composed of multiple registers comprising: an imaging unit that captures images of multiple registers and generates image data; a computational unit that calculates the tilt angle of each of the multiple registers based on the image data; and a determination unit that determines whether the tilt angle is greater than or equal to a predetermined threshold.

Description

Pallet monitoring system and pallet monitoring method

[0001] The present invention relates to a pallet monitoring system and a pallet monitoring method for monitoring pallets in a sintering machine used to produce sintered ore.

[0002] The floor of the pallet of an endless traveling sintering machine, which produces sintered ore for steelmaking, is made up of numerous grate bars on which the sintering raw materials are placed. In an endless traveling sintering machine, air within the sintering raw materials is sucked downward through gaps formed between adjacent grate bars, which causes the combustion and molten zone in the sintering raw materials to move downward, producing sintered ore. The grate bars are supported by adjacent pallet frames and are designed so that they will not come off the pallet even if the pallet is turned over.

[0003] In the case of such a pallet of an endless mobile sinter machine, if the width of the pallet is as large as 5 m, 100 or more grate bars are installed in the width direction of the pallet. The grate bars can fall off from the pallet frame due to impacts such as those caused when the sinter raw materials are loaded onto the pallet or when the raw materials are turned over at the ore feeding and discharging sections.

[0004] When a grate bar falls off, the sinter raw material charged in that area falls into the wind box below, creating a hole. When this happens, air leaks significantly from the hole, preventing the air from flowing around the hole, resulting in unsintered raw material that is not sintered, significantly reducing the sinter yield. If the fallen grate bar is discharged along with the sintered ore, it can get caught in the chute used to transport the sintered ore, causing a blockage or damaging the transport conveyor. Thus, the loss of a grate bar from the pallet has a significant negative impact on the operation of the sinter machine.

[0005] As a technique for detecting the falling off of a grate bar, Patent Document 1 discloses a grate bar falling off detection device for a sintering machine, which measures the distance to the grate bar using a distance meter and determines that the grate bar has fallen off if this distance becomes infinity or increases significantly more than a set distance.

[0006] Japanese Patent Application Publication No. 4-276030

[0007] In Patent Document 1, a distance meter is used to measure the distance from a fixed point to detect the falling of a grate bar early. However, this device detects the falling of a grate bar after it has fallen, and has the problem of not being able to prevent the falling of the grate bar. The present invention has been made in consideration of such conventional technology, and its purpose is to provide a pallet monitoring system and pallet monitoring method that can identify a grate bar that is likely to fall before the grate bar falls off.

[0008] Means for solving the above problems are as follows. [1] A pallet monitoring system for monitoring pallets of a sintering machine whose floor surface is composed of multiple grate bars, the pallet monitoring system comprising: an imaging unit that captures images of the multiple grate bars to generate image data; a calculation unit that calculates the inclination angle of each of the multiple grate bars from the image data; and a determination unit that determines whether the inclination angle is equal to or greater than a predetermined threshold. [2] The pallet monitoring system described in [1], which comprises a distance measurement unit that detects identification information that identifies the pallet. [3] The pallet monitoring system described in [1] or [2], wherein the imaging unit captures images of the multiple grate bars when the pallet passes a predetermined position. [4] The pallet monitoring system described in any of [1] to [3], wherein the calculation unit calculates an average value of the inclination angles of a predetermined number of two or more of the grate bars, and the determination unit determines whether the average value is equal to or greater than a predetermined threshold. [5] The pallet monitoring system described in any of [1] to [4], wherein the imaging unit is a digital camera having a lens and an image sensor, and the lens is coated with a surfactant. [6] A pallet monitoring method for monitoring pallets of a sintering machine whose floor surface is composed of a plurality of grate bars, the pallet monitoring method comprising: an imaging step of imaging the plurality of grate bars to generate image data; a calculation step of calculating the inclination angle of each of the plurality of grate bars from the image data; and a determination step of determining whether the inclination angle is equal to or greater than a predetermined threshold. [7] The pallet monitoring method according to [6], wherein the threshold is determined based on a correspondence relationship between the inclination angle of the grate bar and the number of days until the grate bar falls off.

[0009] The pallet monitoring system and method according to the present invention identify grate bars that are likely to fall off the pallet by determining whether the tilt of the grate bar is equal to or greater than a predetermined threshold. This allows countermeasures to be taken only for grate bars that are likely to fall off before they actually fall off, thereby preventing the fall of grate bars while suppressing increases in maintenance costs.

[0010] FIG. 1 is a schematic diagram showing an example of sintered ore manufacturing equipment. FIG. 2 is a schematic diagram of the top view of a pallet. FIG. 3 is a schematic diagram showing an example configuration of an image processing device. FIG. 4 is a schematic diagram showing a pallet and a grate bar. FIG. 5 is a graph showing the correspondence relationship between the inclination angle of the grate bar and the number of days until the grate bar falls off. FIG. 6 is a diagram showing the flow of a pallet monitoring method according to this embodiment. FIG. 7 is a diagram showing an example of a pallet management table.

[0011] Hereinafter, a pallet monitoring system and a pallet monitoring method according to the present invention will be described using embodiments in which the system and the method are applied to a sintering machine for producing sintered ore. However, the present invention is not limited to these embodiments.

[0012] FIG. 1 is a schematic diagram showing an example of a sinter ore production facility 100. The sinter ore production facility 100 includes a pallet monitoring system 40 according to this embodiment and a sinter machine 10 having a pallet 24 monitored by the pallet monitoring system 40. The sinter machine 10 is, for example, a Dwight Lloyd type sinter machine. In the sinter machine 10, sinter raw materials including iron ore and carbonaceous material are fed from a surge hopper 12 provided in an ore feeding section 34 of the sinter machine 10 by a roll feeder 14 and charged onto an endlessly movable pallet 24, forming a charging layer of sinter raw materials. The thickness of the charging layer is controlled by adjusting the opening of a plurality of dividing gates 16 installed in the width direction of the pallet 24.

[0013] The ignition furnace 18 installed downstream of the ore supply section 34 ignites the carbonaceous material on the upper surface of the sintering bed. Furthermore, air is introduced into the sintering bed by sucking air downward from the blower 22 through the wind box 20 installed below the pallet 24, causing the carbonaceous material contained in the sintering raw materials to combust. Due to the suction of the blower 22, the air in the sintering bed passes through the gaps in the grate bar 26 that constitute the floor of the pallet 24 and flows into the wind box 20. As a result, the combustion position of the carbonaceous material in the sintering bed gradually moves downward. The sintering raw materials are baked and solidified by the heat of combustion of the carbonaceous material, becoming sinter cakes, which are lumps of sintered ore, and are discharged from the ore discharge section 36. In the ore discharge section 36, the sinter cakes that fall from the pallet 24 are crushed, cooled in a cooler, and sized. In this way, sintered ore is produced from the sintering raw materials using the sintering machine 10.

[0014] The sinter machine 10 is provided with 174 pallets 24. Figure 2 is a schematic top view of the pallet 24. In Figure 2, the pallet 24 is provided with side walls 28, grate bars 26, and end grates 30. The side walls 28 are provided on both sides of the pallet 24 to prevent the charged sinter raw material from falling. 150 grate bars 26 are provided in each of three rows, row A, row B, and row C, and a total of 450 grate bars 26 form the floor surface of the pallet 24. The grate bars 26 are supported by engaging their upper and lower ends with a pallet frame (not shown).

[0015] An end grate 30 fixed to the side wall 28 is provided between the grate bar 26 and the side wall 28. The grate bar 26 is installed so as to be movable relative to the pallet frame in a direction perpendicular to the direction of travel of the pallet 24. For this reason, the grate bar 26 tilts due to impacts such as those caused when sinter raw materials are loaded onto the pallet 24 and when the pallet 24 is turned over in the ore supply section 34 and ore discharge section 36. On the other hand, because the end grate 30 is attached to the side wall 28, the end grate 30 will not tilt even if the grate bar 26 tilts due to an impact.

[0016] Referring again to FIG. 1 , the pallet monitoring system 40 according to this embodiment includes an imaging unit 42, a distance measurement unit 44, and an image processing device 46. The imaging unit 42 is located upstream of the ore supply unit 34 in the direction of movement of the pallet 24, and captures an image of the pallet 24 from diagonally above before sinter raw materials are loaded. The imaging unit 42 captures an image of the pallet 24 and generates image data of the pallet 24, including the numerous grate bars 26 that form the floor surface and the end grate 30. The imaging unit 42 transmits the generated image data to the image processing device 46. The imaging unit 42 is, for example, a digital camera having a lens and an image sensor. The image sensor is a CCD sensor or a CMOS sensor.

[0017] The imaging unit 42 detects that the pallets 24 have passed a predetermined position and captures an image of each pallet 24. By detecting that the pallets have passed a predetermined position and capturing an image in this manner, the grate bars 26 and end grates 30 of each pallet 24 can be captured in the same way even if the pallet speed of the pallets 24 changes.

[0018] The fact that the pallet 24 has passed a predetermined position is detected by installing a separate camera (not shown) that continuously captures images of the pallet 24 and monitoring the brightness value of the image data generated by the camera. The brightness value of the image data drops significantly at the connection points between pallets 24, so by detecting this drop in brightness, it is possible to detect that the pallet 24 has passed the predetermined position.

[0019] A large amount of dust is generated when the sintering raw materials are charged and when the sinter cake is discharged. For this reason, it is preferable that a surfactant be applied to the surface of the lens of the imaging unit 42. Applying a surfactant to the lens surface suppresses static electricity buildup on the surface, thereby suppressing dust adhesion to the lens. As a result, before applying the surfactant, the lens had to be cleaned every month to remove dust adhering to the lens, whereas after applying the surfactant, dust did not adhere to the lens even after one year had passed. The surfactant applied to the lens surface may be any of a nonionic surfactant, an anionic surfactant, a cationic surfactant, and an amphoteric surfactant.

[0020] Identification information identifying each of the 174 pallets 24 is engraved on the outer surface of the sidewall 28 of the pallets 24, and a step is formed around the outer edge of the engraving. The distance measurement unit 44 measures the distance from the distance measurement unit 44 to an area including the identification information to create distance information. The distance measurement unit 44 detects the identification information that identifies the pallet 24 by binarizing the distance information of the area to create image data. The distance measurement unit 44 is, for example, a two-dimensional laser displacement meter, and the identification information is information made up of letters, numbers, and / or symbols.

[0021] The distance measurement unit 44 may store model image data with identified identification information in advance, and instead of creating binarized image data, the distance measurement unit 44 may perform geometric pattern matching to determine the similarity between the created image data and the model image data. The distance measurement unit 44 may then detect the identification information by identifying a model image that has a high similarity to the created image data. The distance measurement unit 44 transmits the identified identification information to the image processing device 46.

[0022] The image processing device 46 calculates the inclination angle of each of the plurality of grate bars 26 from the image data transmitted from the imaging unit 42 and determines whether the inclination angle is equal to or greater than a predetermined threshold. The plurality of grate bars 26 that form the floor surface of the pallet 24 are installed so that their longitudinal direction is along the sidewall 28, but they tilt due to impacts when sinter raw materials are loaded onto the pallet 24 and impacts caused by reversals in the ore supply section 34 and the ore discharge section 36, and the inclination angle gradually increases. When the inclination angle of the grate bar 26 exceeds a predetermined inclination angle, the grate bar 26 becomes detached from the pallet frame and falls off the pallet 24. Therefore, by calculating the inclination angle of the grate bar 26 with the image processing device 46 and determining whether the inclination angle is equal to or greater than a predetermined threshold, it is possible to identify the grate bar 26 that is likely to fall off the pallet 24 before it actually falls off.

[0023] Next, the image processing device 46 will be described. Fig. 3 is a schematic diagram showing an example configuration of the image processing device 46. The image processing device 46 is, for example, a general-purpose computer such as a workstation or a personal computer. The image processing device 46 has a control unit 48, an input unit 50, an output unit 52, and a storage unit 54.

[0024] The control unit 48 is, for example, a CPU, and executes various programs stored in the storage unit 54, causing the control unit 48 to function as a calculation unit 56 and a determination unit 58. The input unit 50 is, for example, a keyboard, a touch panel integrated with a display, or the like. The output unit 52 is, for example, an LCD or CRT display. The storage unit 54 is, for example, an updatable flash memory, a built-in hard disk or a hard disk connected via a data communication terminal, an information recording medium such as a memory card, and a read / write device for the same. The storage unit 54 stores programs and data used to calculate the inclination angle of the grate bar 26. The storage unit 54 also stores template image data that is created in advance and used to create a palette management table, which will be described later.

[0025] Next, a description will be given of the processing executed by the calculation unit 56 and the determination unit 58. When the calculation unit 56 receives the image data generated by the imaging unit 42, it calculates the inclination angle of each grate bar 26 using the received image data.

[0026] FIG. 4 is a schematic diagram showing the pallet 24 and the grate bar 26. FIG. 4(a) is a top view of the pallet 24, and FIG. 4(b) is an enlarged view of the Y portion of FIG. 4(a). As shown in FIG. 4(b), the calculation unit 56 identifies five points, for example, at five different positions along the longitudinal direction of the predetermined grate bar 26, where the positions on both longitudinal side surfaces of the grate bar 26 are halved, and calculates the inclination angle of the approximate line 32 of the five points. The inclination angle of the grate bar 26 is an angle with the longitudinal direction of the end grate 30 as the reference (0°). After calculating the inclination angles of all the grate bars 26, the calculation unit 56 transmits the calculated inclination angles to the determination unit 58.

[0027] When the determination unit 58 acquires the tilt angle from the calculation unit 56, the determination unit 58 determines whether the tilt angle is equal to or greater than a threshold value of 6°. The determination unit 58 reads the threshold value from the storage unit 54 and compares the tilt angle with the threshold value to determine whether the tilt angle is equal to or greater than 6°. In the present embodiment, 6° is an example of a predetermined threshold value for the tilt angle, and the threshold value is predetermined and stored in the storage unit 54.

[0028] FIG. 5 is a graph showing the relationship between the inclination angle of the grate bar 26 and the number of days until the grate bar 26 falls off. In FIG. 5, the horizontal axis represents the inclination angle (°) of the grate bar 26, and the vertical axis represents the number of days (days) until the grate bar 26 falls off. As shown in FIG. 5, if the inclination angle of the grate bar 26 is 6° or less, the grate bar 26 will not fall off for at least 30 days. In the sintering machine 10 according to this embodiment, the pallets 24 are repaired and the grate bars 26 are reinstalled every month. Therefore, by determining whether the inclination angle of the grate bar 26 is 6° or more and identifying grate bars with an inclination angle of 6° or more, it is possible to identify grate bars 26 that are likely to fall off the pallet 24 before regular repair is performed.

[0029] In this way, it is preferable to determine the threshold value of the inclination angle based on the correspondence relationship between the inclination angle of the great bar 26 and the number of days until the great bar 26 falls off. Then, the threshold value is set to an inclination angle such that the number of days until the great bar 26 falls off is longer than the period during which regular repairs are performed. This makes it possible to identify great bars 26 that are likely to fall off the pallet 24 before regular repairs are performed.

[0030] When the identification information of the pallet 24 is acquired from the distance measurement unit 44, the determination unit 58 identifies the position of the grate bar whose inclination angle is 6° or greater in association with the identification information of the pallet 24. The determination unit 58 identifies the positions of the grate bars whose inclination angle is greater than or equal to the threshold value, for example, by using columns A to C and numbers starting from 150, with the left end of each column being numbered 1. The determination unit 58 displays the positions of the identified grate bars whose inclination angle is greater than or equal to the threshold value, along with the inclination angle of the grate bar, on the output unit 52. This allows the operator of the sintering machine 10 to identify grate bars that are likely to fall off the pallet 24. As a result, the operator can take measures to prevent falloff by limiting the measures to grate bars that are likely to fall off before regular maintenance, thereby preventing grate bar falloff while suppressing increases in maintenance costs.

[0031] Fig. 6 is a diagram showing the flow of the pallet monitoring method according to this embodiment. The flow of the pallet monitoring method according to this embodiment will be explained using Fig. 6. The flow of the pallet monitoring method shown in Fig. 6 is started, for example, when the image processing device 46 is started and the input unit 50 receives an instruction from the operator to start pallet monitoring.

[0032] The imaging unit 42 captures an image of the pallet 24 and generates image data (step S101). The imaging unit 42 transmits the generated image data to the image processing device 46. This step is the imaging step.

[0033] The distance measurement unit 44 acquires the identification information of the pallet 24 (step S102). The distance measurement unit 44 transmits the acquired identification information to the image processing device 46. This step is the identification information detection step. The identification information detection step (step S102) by the distance measurement unit 44 is not limited to this position. The identification information detection step (step S102) may be performed before the imaging step (step S101) by the imaging unit 42, as long as it is performed before the determination step (step S104) by the determination unit 58, which will be described later. Similarly, the identification information detection step (step S102) may be performed after the calculation step (step S103) by the calculation unit 56.

[0034] When the calculation unit 56 receives the image data from the imaging unit 42, it uses the image data to calculate the inclination angles of all the grate bars 26 of the pallet 24 (step S103). The calculation unit 56 outputs the calculated inclination angles of the grate bars 26 to the determination unit. This step is the calculation step.

[0035] When the determination unit 58 acquires the tilt angle of the great bar 26 from the calculation unit 56, it determines whether the tilt angle is equal to or greater than a threshold value (step S104). This step is the determination step. When the determination unit 58 receives identification information of the pallet 24 captured by the imaging unit 42 from the distance measurement unit 44, it identifies the position of the great bar whose tilt angle is equal to or greater than the threshold value in association with the identification information, and causes the output unit 52 to display the position.

[0036] The determination unit 58 determines whether an instruction to end pallet monitoring has been received from the operator (step S105). If the input unit 50 has not received an instruction to end pallet monitoring from the operator, the determination unit 58 determines that an instruction to end pallet monitoring has not been received (step S105: No), and returns the process to step S101. Then, the process from step S101 to step S104 is repeatedly executed for the next pallet 24. By repeatedly executing the process from step S101 to step S104 in this manner, it is possible to sequentially monitor the 174 pallets 24 provided in the sintering machine 10 and identify grate bars that are likely to fall off these pallets 24.

[0037] On the other hand, if the input unit 50 has received an instruction from the operator to end pallet monitoring, the determination unit 58 determines that an instruction to end pallet monitoring has been received (step S105: Yes), and ends the flow of the pallet monitoring method shown in Figure 6.

[0038] In this way, the pallet monitoring method according to this embodiment monitors the pallets 24 of the sintering machine 10 and can identify any great bars that are likely to fall off the pallet 24. This allows measures to be taken to prevent the great bars from falling off only if they are likely to fall off, before they actually fall off, making it possible to prevent the great bars from falling off while suppressing increases in maintenance costs.

[0039] The present invention is not limited to the above embodiment and various modifications can be made. In the above embodiment, the determination unit 58 determines whether the inclination angle of each great bar 26 is equal to or greater than a threshold value, but the present invention is not limited to this. For example, the determination unit 58 may determine whether the average value of the inclination angles of 10 great bars is equal to or greater than a threshold value. 10 is an example of a predetermined number of 2 or more for calculating the average inclination angle.

[0040] In this case, the calculation unit 56 calculates the inclination angles of the 450 great bars 26, and then calculates the average value of the inclination angles of every 10 great bars 26 to obtain the average value of the inclination angles of 45 great bars 26 per pallet. The calculation unit 56 outputs the average value of the inclination angles of the 45 great bars 26 to the determination unit 58.

[0041] The multiple grate bars 26 are installed adjacent to each other. Therefore, when one grate bar tilts, the tilt of the grate bar affects the neighboring grate bars, causing them to tilt as well. In this way, the tilt of one grate bar affects the surrounding grate bars, so the tilt angle of a specific grate bar does not increase. Therefore, even if the tilt angle of a grate bar 26 is set to the average value of the tilt angles of ten grate bars 26, the pallet 24 can be monitored with the same accuracy as the tilt angle of a single grate bar 26.

[0042] When the determination unit 58 acquires the average value of the tilt angles from the calculation unit 56, the determination unit 58 determines whether the average value of the tilt angles is equal to or greater than a threshold value. The determination unit 58 reads the threshold value from the storage unit 54 and compares the threshold value with the average value of each tilt angle to determine whether the average value of each tilt angle is equal to or greater than a threshold value.

[0043] 7 is a table showing an example of the pallet management table 60. The determination unit 58 determines whether the average value of the inclination angles of all the grate bars 26 in columns A to C of the pallet 24 is 6° or greater. The determination unit 58 then reads template image data from the storage unit 54, and creates image data for the pallet management table 60 using the average inclination angles, the determination result, the pallet identification information, and the image data. The template image data used to create the pallet management table 60 has been created in advance and stored in the storage unit 54.

[0044] The pallet management table 60 includes pallet identification information and the average tilt angle corresponding to the position of the grate bar 26 for each of columns A to C. Average values ​​of tilt angles equal to or greater than 6°, which is the threshold value for tilt angles, are preferably displayed in a different manner from other average values. In the example shown in FIG. 7, the display area for average values ​​of tilt angles equal to or greater than 6° is displayed in a different color. The determination unit 58 causes the output unit 52 to display the created pallet management table 60.

[0045] In this way, the pallet monitoring system 40 according to this embodiment may monitor the inclination angle of the grate bars 26 using the average value of the inclination angles of a predetermined number of two or more grate bars 26. This reduces the number of data items to be monitored, making it possible to efficiently monitor the pallets 24 of the sintering machine 10 and identify grate bars that are likely to fall off the pallets 24.

[0046] In the above embodiment, an example was shown in which the average inclination angle of every 10 great bars 26 was calculated, but this is not limiting. The calculation unit 56 may also calculate the maximum inclination angle of every 10 great bars 26. In this case, the calculation unit 56 outputs the maximum inclination angle of the 45 great bars 26 to the determination unit 58, which determines whether the maximum inclination angle is equal to or greater than a threshold value. By making this determination, even if the inclination angle of a specific great bar 26 suddenly increases, it is possible to identify the great bar that is likely to fall off the pallet 24 and efficiently monitor the pallet 24.

[0047] REFERENCE SIGNS LIST 10 Sintering machine 12 Surge hopper 14 Roll feeder 16 Dividing gate 18 Ignition furnace 20 Wind box 22 Blower 24 Pallet 26 Grate bar 28 Side wall 30 End grate 32 Approximate line 34 Ore supply section 36 Ore discharge section 40 Pallet monitoring system 42 Imaging section 44 Distance measurement section 46 Image processing device 48 Control section 50 Input section 52 Output section 54 Storage section 56 Calculation section 58 Determination section 60 Pallet management table 100 Sinter ore manufacturing equipment

Claims

1. A pallet monitoring system for monitoring a pallet of a sintering machine whose floor surface is made up of a number of grate bars, comprising: an imaging unit that images the number of grate bars and generates image data; a calculation unit that calculates the inclination angle of each of the number of grate bars from the image data; and a determination unit that determines whether the inclination angle is equal to or greater than a predetermined threshold value.

2. A pallet monitoring system according to claim 1, further comprising a distance measuring unit for detecting identification information for identifying said pallet.

3. A pallet monitoring system as described in claim 1 or claim 2, wherein the imaging unit images the plurality of grate bars when the pallet passes a predetermined position.

4. A pallet monitoring system as described in any one of claims 1 to 3, wherein the calculation unit calculates the average value of the inclination angles of a predetermined number of the grate bars, which number is two or more, and the determination unit determines whether the average value is greater than or equal to a predetermined threshold value.

5. A pallet monitoring system as claimed in any one of claims 1 to 4, wherein the imaging unit is a digital camera having a lens and an image sensor, and the lens is coated with a surfactant.

6. A pallet monitoring method for monitoring a pallet of a sintering machine whose floor surface is made up of a plurality of grate bars, comprising: an imaging step of imaging the plurality of grate bars to generate image data; a calculation step of calculating the inclination angle of each of the plurality of grate bars from the image data; and a determination step of determining whether the inclination angle is equal to or greater than a predetermined threshold value.

7. A pallet monitoring method according to claim 6, wherein the threshold value is determined based on a corresponding relationship between the inclination angle of the grate bar and the number of days until the grate bar falls off.

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