JP6466827B2 - Reduced iron production equipment - Google Patents

Description

The present invention relates to a production equipment of the reduced iron having a reducing furnace having a rotary hearth.

  Conventionally, a reduction furnace having a rotary hearth is known as an apparatus for producing reduced iron. The reduction furnace has a hearth movable in the rotation direction and a ceiling positioned above the hearth, and these are constituted by a refractory material such as brick. On the hearth, pellets as a raw material of the reduced iron are charged at a specific charging position. The pellets are reduced by being heated on the hearth, moved to a specific distance (for example, about the entire circumference of the hearth) from the charging position, and then reached a specific discharge position and provided in the discharge device. It is discharged out of the furnace by the discharge device. The discharge is performed, for example, by rotational driving of a discharge screw having a main body shaft and a feed blade formed around the main shaft.

JP2012-072494A

  In such a rotating bed type reduction furnace, as the operation continues, deterioration of the discharge device, for example, wear of the blades for feeding the discharge screw constituting the discharge device proceeds. Under such circumstances, the discharge screw and the like have been regularly replaced in the past, but the operation of the entire reduction furnace has to be stopped at the time of replacement, thereby significantly improving the operation efficiency. descend. Therefore, reducing the replacement frequency of the discharge device is an important issue in the operation of the reduction furnace.

The present invention Oite the production equipment of the reduced iron having a rotary hearth reducing furnace, and to provide what can be improved its operating efficiency.

  The present inventors paid attention to the correlation between the state of the hearth of the reduction furnace and the progress of deterioration of the discharge device as means for solving the above-mentioned problems. That is, the cause of deterioration of the exhaust device is wear damage of the specific portion due to excessive contact between the surface of the hearth and the specific portion of the exhaust device (for example, blades constituting the discharge screw). If the surface condition of the floor is well managed, the replacement frequency of the discharge device can be reduced.

  Note that the “surface of the hearth” here is generated not only from the hearth already installed in the reduction furnace, but also from the reduced iron raw material and the reaction product laid on the hearth, the reduced iron raw material. It means the entire surface of the part that moves together with the hearth, including powder, floor covering, and the like. The same applies to the following description.

  Furthermore, the present inventors, as an area for actually monitoring the surface of the hearth, is a discharge position where the reduced iron is discharged upstream from the charging position where the reduced iron material is charged on the hearth. We focused on the downstream area. In this region, reduced iron has been discharged from the hearth at the discharge position, and no new reduced iron raw material has been charged on it, and almost no powder is scattered from the reduced iron raw material. This is the most suitable area for properly monitoring the condition of the hearth surface. In addition, since the hearth moves in the rotation direction, the information on the surface state of the hearth acquired in the region is sequentially accumulated to monitor the surface state over the entire circumference of the hearth. Information can be created.

  This invention is made | formed from such a viewpoint, and provides the apparatus for manufacturing reduced iron by heat-processing the reduced iron raw material containing a carbonaceous reducing agent and iron oxide. This apparatus includes a reduction furnace including a hearth that moves in a rotation direction and a heater that generates reduced iron by heating reduced iron raw material on the hearth, and a charge position set on the hearth on the hearth. A raw material charging device for charging the reduced iron raw material to the reduced iron raw material, and the reduced iron raw material by the heater on the hearth at a discharge position away from the charging position in the moving direction of the hearth on the hearth A discharge device that sends out and discharges reduced iron generated by heating in a direction crossing the moving direction of the hearth, and downstream of the discharging position and upstream of the charging position in the moving direction of the hearth And a monitoring device for monitoring the state of the surface of the hearth in the monitoring target region set in (1). The monitoring device includes a detection unit that detects information related to a state of the surface of the hearth in the monitoring target region, and accumulates information related to a state of the surface of the hearth detected by the detection unit. A monitoring information creation unit that creates monitoring information about the surface state of the hearth over the entire circumference of the floor; and an output unit that outputs the monitoring information created by the monitoring information creation unit.

  According to this apparatus, it is possible to provide monitoring information suitable for monitoring the hearth surface over the entire circumference of the hearth based on accumulation of information on the surface state of the hearth detected in the specific region. It is. The monitoring information allows the user to take appropriate measures (for example, maintenance of the hearth surface) based on the monitoring information.

  The detection unit detects a height information detector that detects information about the height of the surface and a temperature information detector that detects information about the temperature of the surface as information about the surface of the hearth. Is preferred. Since the height of the surface is a factor that directly affects the deterioration of the discharge device due to contact between the surface and the discharge device, information on the distribution of the height, that is, the undulation of the surface, controls the discharge device. It is very useful to do. Further, since the temperature of the surface changes depending on the properties of the surface, it is possible to indirectly grasp parameters relating to the surface state such as undulation and material based on the information on the temperature distribution of the surface. .

  Preferably, the monitoring information creation unit creates a monitoring image representing the distribution of the information based on the information detected by the detection unit. The monitoring image helps the user to easily understand the surface state of the hearth. For example, when the detection unit includes the height information detector, the monitoring information generation unit generates an image (for example, a three-dimensional image or a two-dimensional image including contour lines) indicating the height distribution of the hearth surface. It is preferable to create. Moreover, when the said detection part contains the said temperature information detector, it is preferable that the said monitoring information preparation part produces the image which shows the temperature distribution of the said hearth.

  The monitoring device receives an input of the warning command and a warning necessity determination unit that creates a warning command when information on the surface state of the hearth detected by the detection unit exceeds a preset allowable range. It is preferable to further include a warning output unit that outputs a warning. The warning clearly notifies that there is an abnormality on the surface of the hearth, and enables the countermeasure to be performed reliably. For example, when the detection unit includes the height information detector, the monitoring information generation unit generates an image (for example, a three-dimensional image or a two-dimensional image including contour lines) indicating the height distribution of the hearth surface. It is preferable to create. Moreover, when the said detection part contains the said temperature information detector, it is preferable that the said monitoring information preparation part produces the image which shows the temperature distribution of the said hearth.

Also, a method for producing reduced iron is provided by heating the reduced iron raw material containing iron oxide and carbonaceous reducing agent. In this method, the reduced iron material is charged at a preset charging position on the hearth of a reduction furnace having a hearth moving in the rotation direction, and the reduced iron material charged on the hearth The reduced iron produced by the reduction step is provided at a discharge position away from the charging position in the moving direction of the hearth. The object to be sent is discharged from the hearth in the direction intersecting the moving direction of the hearth by the discharging device, and the monitoring target is downstream of the discharging position and upstream of the charging position in the moving direction of the hearth. Monitoring the surface of the hearth in the area, and performing maintenance on the surface of the hearth (for example, checking and maintaining the surface of the hearth) based on the state of the surface of the hearth in the monitored area; including.

As described above, according to the present invention, Oite the production equipment of the reduced iron having a rotary hearth reducing furnace, those capable of improving the operating efficiency is provided.

It is a top view of the reduced iron manufacturing apparatus which concerns on embodiment of this invention. It is the II-II sectional view taken on the line of FIG. It is a side view which shows the discharge screw of the discharge device provided in the said reduction furnace. It is a figure which shows the cross section along the centerline of the width direction of the hearth of the said reduction furnace, Comprising: It is sectional drawing which shows the process part of the said reduction furnace. It is a figure which shows the cross section along the radial direction of the said reduction furnace, Comprising: It is sectional drawing which shows arrangement | positioning of the sensor provided in the said reduction furnace. It is a block diagram which shows the monitoring apparatus containing the said sensor. It is a figure which shows the example of the image which is the image for monitoring produced in the said monitoring apparatus, and shows the height distribution of the surface of the whole hearth. It is a figure which shows the example of the image which is the monitoring image produced in the said monitoring apparatus, and expanded and showed the designated area | region among the monitoring images shown in FIG. It is a figure which shows the example of the image which is a monitoring image produced in the said monitoring apparatus, and shows distribution of the surface temperature of the whole hearth. FIG. 10 is a diagram illustrating an example of an image generated by the monitoring apparatus, the image being an enlarged view of a designated area of the monitoring image illustrated in FIG. 9. It is a figure which shows the example of the image which is a monitoring image produced in the said monitoring apparatus, Comprising: The distribution of the hearth height distribution in the specific circumferential direction position and the distribution of the surface temperature of a hearth in the cross section are displayed. .

  Preferred embodiments of the present invention will be described with reference to the drawings.

  1 to 6 show a reduced iron manufacturing apparatus according to an embodiment of the present invention. This apparatus is for producing reduced iron by sequentially heat-treating a large number of reduced iron raw materials 2 each containing a carbonaceous reducing agent and iron oxide. Each reduced iron raw material 2 is formed in a spherical shape, but may not be a perfect sphere. This point will be mentioned later. Moreover, it is preferable that each reduced iron raw material 2 is dried in advance.

  The apparatus includes a rotary bed type reduction furnace 10, a raw material charging device 12, and a discharge device 14. Furthermore, a floor covering material supply device 16 may be provided. The reduction furnace 10 generates reduced iron (metallic iron) by processing the reduced iron raw material 2 charged therein. Specifically, in the reduction furnace 10, the iron oxide is heated, reduced, melted, agglomerated, slag is separated, cooled, and the like. The raw material charging device 12 sequentially charges the reduced iron raw materials 2 into the reduction furnace 10. The discharge device 14 discharges reduced iron, slag, and the like generated in the reduction furnace 10 to the outside of the reduction furnace 10.

  The reduction furnace 10 includes a hearth 18, a hearth drive device 19 that moves the hearth 18 in the rotation direction, and a furnace body 20. The hearth 18 and the furnace body 20 are made of, for example, a refractory material mainly composed of alumina. The furnace body 20 integrally includes an inner peripheral wall 22, an outer peripheral wall 23, and a ceiling 24.

  The hearth 18 has an annular shape surrounding a circular space inside, and has a certain width along the radial direction. The hearth drive device 19 is provided below the hearth 18 as shown in FIG. 5, and the hearth 18 is in a predetermined direction around the vertical axis that is the central axis thereof (counterclockwise direction in FIG. 2). ) While moving the hearth 18 so as to rotate at a predetermined speed.

  The raw material charging device 12 charges the reduced iron raw material 2 at a charging position set on the hearth 18. Specifically, as shown in FIG. 2, it has a hopper 12a for dropping the reduced iron raw material 2 on the hearth 18 and a conveyor 12b for supplying the reduced iron raw material 2 to the hopper 12a.

  The discharge device 14 is separated from the charging position on the hearth 18 in the moving direction of the reduced iron raw material 2 (in this embodiment, separated from the charging position by a distance close to the entire circumference). To discharge reduced iron and slag. The discharge device 14 according to this embodiment includes a discharge screw 25 as shown in FIG. 3 and a motor 26 that rotates the discharge screw 25. The discharge screw 25 includes a main body shaft 25a and a feeding blade 25b that spirally advances on the outer peripheral surface of the main body shaft 25a. As the discharge screw 25 rotates, the feeding blade 25b is It arrange | positions in the height position which scrapes the reduced iron etc. on the hearth 18 out of a furnace.

  The floor covering material replenishing device 16 replenishes the floor covering material 11 on the hearth 18 at a floor covering material replenishing position set between the charging position and the discharging position. The floor covering material 11 is for protecting the hearth 18, specifically, preventing direct contact between the hearth 18 and the reduced iron raw material 2, and is composed of a large number of powders. .

  The replenishment of the floor covering material 11 is not essential in the present invention. That is, the present invention includes an embodiment in which the reduced iron raw material is directly charged on the hearth.

  The floor covering material replenishing device 16 replenishes the furnace floor 18 with new floor covering material 11 corresponding to the amount of the floor covering material 11 discharged together with the reduced iron and the slag in the discharging device 14 as appropriate. As shown in FIG. 2, the floor covering material replenishing device 16 according to this embodiment includes a hopper 16a for dropping the floor covering material 11 on the hearth 18 as shown in FIG. And a conveyor 16b for supplying the floor covering material 11 to the hopper 16a.

  In this embodiment, a raw material leveling position and a flooring material leveling position are set on the downstream side of the raw material charging device 12 and the flooring material supply device 16, respectively. A raw material leveling device 13 and a floor covering material leveling device 17 are provided at the respective positions.

  The raw material leveling device 13 leveles the reduced iron raw material 2 charged on the hearth 18 in a direction orthogonal to the moving direction of the hearth 18, that is, in the width direction of the hearth 18, as shown in FIG. It has a leveling screw 13s as shown. Similar to the discharge screw 25, the leveling screw 13s includes a main body shaft 13a and a feeding blade 13b.

  Similarly, the floor covering material leveling device 17 equalizes the floor covering material 11 supplied onto the hearth 18 in the width direction, and has a leveling screw 17s as shown in FIG. The leveling screw 17s also has a main body shaft 17a and a feeding blade 17b.

  The reducing furnace 10 includes a plurality of burners 28 as shown in FIG. 4 in order to reduce and melt the reduced iron raw material 2. These burners 28 are respectively provided at a plurality of positions along the moving direction of the hearth 18 in the region from the charging position to the discharge position, and fuel is burned at each position. The heat by this combustion is transmitted to each reduced iron raw material 2 sequentially charged in the furnace by radiation or the like, and contributes to the reduction and melting of the reduced iron raw material 2.

  The reduced iron manufacturing apparatus further includes a hearth monitoring apparatus as shown in FIGS. 5 and 6. Details will be described below.

  The hearth monitoring device monitors the state of the surface of the hearth 18 in the monitoring target area Amt which is the area of the hearth 18 shown in FIG. This monitoring target area Amt is an area set downstream of the discharge position and upstream of the charging position in the moving direction of the hearth 18. In the case where the floor covering material 11 is replenished as in this embodiment, as shown in FIG. 1, the floor covering material replenishing device 12 is provided downstream of the discharge position where the discharging device 14 is provided. It is more preferable that the monitoring target area Amt is set on the upstream side of the floor covering material replenishment position.

  The hearth monitoring apparatus includes a detection unit 40, a calculation control unit 50, and an output unit 60 shown in FIG.

  The detection unit 40 is a section that detects information related to the state of the surface of the hearth 18 in the monitoring target area Amt. The detection unit 40 according to this embodiment includes a plurality of distance sensors (height information detectors) 42 for detecting information about the height of the surface of the hearth 18 and the temperature of the surface of the hearth 18. And a plurality of temperature sensors (temperature information detectors) 44 for detecting information about.

  The plurality of distance sensors 42 are arranged on the ceiling 24 located above the hearth 18 in the monitoring target area Amt, and are arranged at intervals in the width direction of the hearth 18. Each distance sensor 42 is constituted by, for example, a laser sensor or an ultrasonic sensor, and creates a distance detection signal that is an electrical signal corresponding to the distance from the distance sensor 42 to the surface of the hearth 18. The height of the surface of the hearth 18 is specified based on the distance detected by the distance sensor 42 and the height position of the distance sensor 42.

  Each distance sensor 42 can reciprocally scan in the width direction, and thereby scans a region in the width direction allocated to the distance sensor 42. In this way, the height of the portion located below the plurality of distance sensors 42 in the hearth 18 is detected in a short time over the entire width direction.

  The plurality of temperature sensors 44 are shifted from the distance sensors 42 in a direction parallel to the moving direction of the hearth 18, like the distance sensor 42, above the hearth 18 in the monitoring target area Amt. Are arranged on the ceiling 24 located at a distance from each other in the width direction of the hearth 18. Each temperature sensor 44 is composed of, for example, a radiation thermometer, a thermal image measurement device, or the like, and creates a temperature detection signal that is an electrical signal corresponding to the temperature of the surface of the hearth 18.

  Each temperature sensor 44 also reciprocally scans an area assigned to the temperature sensor 44 in the width direction of the hearth 18. In this manner, the temperature of a portion of the hearth 18 located below the plurality of temperature sensors 44 is detected in a short time over the entire width direction.

  Detection by the distance sensor 42 and the temperature sensor 44 is continuously performed during operation of the reduction furnace, that is, during movement of the hearth 18. Moreover, since the moving speed of the hearth 18 is sufficiently slower than the scanning speed of the sensors 42 and 44, the height and temperature of the part of the hearth 18 passing through the monitoring target area Amt are detected one after another. Is done.

  In order to protect the sensors 42 and 44 from high heat, a protective material 29 such as a refractory as shown in FIG. 5 may be interposed between the sensors 42 and 44 and the hearth 18. In this case, it is preferable that the protective material 29 (the protective material 29 and the ceiling 24 depending on the arrangement) be provided with a window that allows the sensors 42 and 44 to detect the surface state of the hearth 18. Alternatively, the sensors 42 and 44 may be cooled by a coolant such as water.

  The arithmetic control unit 50 is constituted by, for example, a microcomputer, and has a monitoring image creation unit 52 and a warning necessity determination unit 54 shown in FIG.

  The monitoring image creation unit 52 captures and accumulates the distance detection signal and the temperature detection signal created by the distance sensor 42 and the temperature sensor 44 from time to time, thereby storing the hearth over the entire circumference of the hearth 18. Monitoring information for monitoring the state of the surface of 18, specifically, an image showing the height distribution of the surface over the entire circumference of the hearth 18, for example, a three-dimensional image and a two-dimensional image including contour lines, Data about a graph showing the height of the surface at the position, etc., and an image showing the temperature distribution over the entire circumference of the hearth 18, for example, a three-dimensional image or a two-dimensional image including an isotherm, a surface at each position And data about a graph or the like indicating the temperature of the image, and the image data is input to the output unit 60.

  FIG. 7 shows an example of a monitoring image created by the monitoring image creation unit 52 and showing the height distribution of the surface of the entire hearth 18 (that is, the entire monitoring image). In this image, the area of the hearth is divided into 10 areas A1 to A10 in the circumferential direction, and the contour line 70 and the pattern 72 of the height distribution (unevenness) on the surface of the hearth in each area are used as a reference. Displayed by combination.

  Further, when a specific area among the areas A1 to A10 is selected by a user's operation, a partially enlarged image as shown in FIG. 8 is displayed for the area. FIG. 8 shows an image displayed when the area A9 shown in FIG. 7 is selected. In this image, detailed information on the height distribution in the area A9 is displayed. Further, when an arbitrary cross-section indicating line 74 is designated in this image, a cross-sectional image 76 along the line is displayed at one corner of the screen.

  Similarly, FIG. 9 is an example of an image (that is, an image for overall monitoring) showing the distribution of the surface temperature over the entire circumference of the hearth 18, which is a monitoring image created by the monitoring image creation unit 52. Show. Also in this image, the area of the hearth is divided into 10 areas A1 to A10 in the circumferential direction, and the distribution of the hearth surface temperature in each area is an isotherm based on a specific temperature (800 ° C in the figure). A combination of 80 and pattern 82 is displayed.

  Further, when a specific area among the areas A1 to A10 is selected by the user's operation, a partially enlarged image as shown in FIG. 10 is displayed for the area. FIG. 10 shows an image that is displayed when the area A10 shown in FIG. 9 is selected. In this image, detailed information on the height distribution in the area A10 is displayed. Further, when an arbitrary cross-section indicating line 84 is designated in this image, a cross-sectional image 86 in which the temperature distribution along the line is displayed by height is displayed at one corner of the screen.

  Or it is also possible to display the composite image which shows both the height and temperature of a hearth surface in arbitrary cross sections. FIG. 11 shows an example of a composite image in which the distribution of the height of the hearth and the distribution of the surface temperature of the hearth at a specific circumferential position of the hearth are represented by cross-sectional shapes and gradations, respectively.

  Note that the monitoring information created in the present invention is not limited to the monitoring image as described above (an image showing the height distribution of the hearth surface or an image showing the temperature distribution). The monitoring information includes, for example, a correspondence relationship between coordinates set on the hearth (for example, coordinates in which a radial position and a circumferential position are combined) and surface state indicators (for example, height and temperature) at the coordinate positions. It may be a numerical table indicating. Alternatively, only the maximum value and the minimum value of the surface state index may be collected as monitoring information.

  The warning necessity determination unit 54 determines whether or not the height and temperature of the hearth 18 specified by the distance sensor 42 and the temperature sensor 44 are within a preset allowable range. If at least one of the temperature and the temperature is out of the allowable range, a warning command is created and input to the output unit 60. Specifically, the warning necessity determination unit 54 according to this embodiment selects the maximum value and the minimum value of the surface height and the surface temperature accumulated over the entire circumference of the hearth 18, and the following a) to d) Create a warning command if any of the above applies.

a) When the maximum value of the hearth surface height is larger than a preset height upper limit value b) When the minimum value of the hearth surface height is smaller than a preset height lower limit value c) The hearth When the maximum value of the surface temperature is larger than the preset upper temperature limit value d) When the minimum value of the hearth surface temperature is smaller than the preset lower temperature limit value Alternatively, for the surface height or the surface temperature, The warning command may be generated when the difference between the maximum value and the minimum value is a certain value or more, that is, when the variation is large.

  Also, the amount of change in the hearth surface height over time or the amount of change in the hearth surface temperature over time (i.e., the horizontal axis is elapsed time, the vertical axis is hearth surface height or hearth surface The warning command may be generated when a slope of a tangent to a curve drawn when the temperature is exceeded exceeds a preset allowable value.

  The output unit 60 is a section that outputs and notifies the information created by the arithmetic control unit 50 to the outside, and includes an image display unit 62 and a warning output unit 64. The image display unit 62 receives the input of the image data from the monitoring image display unit 52 and displays the monitoring image created by the monitoring image creation unit 52 on the display screen. The warning output unit 64 includes, for example, a warning lamp or a warning buzzer. When the warning command is input from the warning necessity determination unit 54, the warning output unit 64 turns on the warning lamp or activates the warning buzzer. Do.

  Next, the operation of this reduced iron manufacturing apparatus will be described.

  During operation of the reduction furnace 10, the hearth drive device 19 is always operated to move the hearth 18 in the rotation direction at a constant speed. The floor covering material replenishing device 16 provided at the floor covering material replenishment position supplies the floor covering material 11 to the hearth 18, and further, the raw material charging device 12 provided at the downstream charging position. Is charged with the reduced iron raw material 2 pelletized or briquetted on the hearth 18 (in this embodiment, on the floor covering material 11). The reduced iron raw material 2 is transported in the moving direction together with the hearth 18, and the temperature of the reduced iron raw material 2 is increased by a burner 28 shown in FIG. Melting takes place. Thereby, granular molten metal iron, slag, etc. are produced | generated. The molten metal iron is then cooled and solidified to become product reduced iron 2r. Here, melting of the reduced iron raw material 2 is not necessarily performed.

  The reduced iron, slag, and the like generated in this manner are discharged out of the furnace by the discharge device 14 provided at the discharge position. In this embodiment, the discharge screw 25 shown in FIG. 3 is rotationally driven by a motor 26 at a position immediately above the surface of the hearth 18, whereby a spiral feed blade 25 b included in the discharge screw 25. Scrapes reduced iron, slag and the like on the hearth 18 in the width direction of the hearth 18.

  In the monitoring target area Amt, which is an area downstream of the discharge position where the discharge device 14 is provided and upstream of the floor covering material supply position, the surface of the hearth 18 is monitored by the hearth monitoring apparatus. Is called.

  Specifically, the distance sensor 42 and the temperature sensor 44 of the hearth monitoring device respectively include the distance from the distance sensor 42 to the surface of the hearth 18 and the hearth 18 during the movement of the hearth 18 in the rotation direction. The temperature of the surface is detected, and the detection signal is input to the arithmetic control unit 50 every moment. The monitoring image creating unit 52 of the arithmetic control unit 50 accumulates detection signals input from the sensors 42 and 44, that is, information on the hearth surface state, and based on this, the height of the surface of the hearth 18 and An image showing the temperature distribution is formed and output to the image display unit 62 of the output unit 60. Further, the warning necessity determination unit 54 of the arithmetic control unit 50 specifies the maximum value and the minimum value for each of the height and temperature of the surface of the hearth 18 collected over the entire circumference of the hearth 18, and When any value deviates from a preset allowable range, a warning command is input to the warning output unit 64 of the output unit 60 to perform a warning operation. Also, when the amount of change in the hearth surface height over time or the amount of change in the hearth surface temperature over time exceeds a preset allowable value, the warning output of the output unit 60 is also output. It is also possible to input a warning command to the unit 64 to perform a warning operation.

  In the monitoring target area Amt monitored by the hearth monitoring device, the reduced iron, slag, and the like are discharged by the discharge device 14 and the new floor covering material 11 is replenished and the new reduced iron raw material 2 is still charged. In this monitoring target area Amt, the hearth monitoring device can monitor the surface of the hearth 18 under the most preferable conditions.

  Specifically, the monitoring by the hearth monitoring device enables effective management of the hearth 18 as follows.

(A) About the height of the surface of the hearth 18 By collecting information on the height of the surface of the hearth 18 over the entire circumference, it is possible to specify the undulations of the surface, that is, the presence of irregularities. The unevenness on the surface may be caused by excess or deficiency or non-uniformity of charging of the reduced iron raw material 2, accumulation of fine powder generated from the reduced iron raw material 2, and the like. Even with the floor covering material leveling device 17, it is difficult to avoid it completely. And since the presence of the unevenness greatly affects the progress of the deterioration of the discharge device 14, the early detection is extremely effective in suppressing the deterioration of the discharge device 14. Specifically, it is as follows.

(A-1) Convex Part A part (convex part) that protrudes larger than the other part on the surface of the hearth 18 directly contacts the feeding blade 25 b of the discharge screw 25 in the discharge device 14. This will be worn and damaged. The degree is more remarkable as the height of the convex portion is larger. Therefore, it is possible to remarkably improve the operation efficiency by detecting the existence of the convex portion at an early stage and carrying out individual maintenance of the hearth surface so as to partially equalize it.

  Specifically, suppressing the deterioration of the discharge device 14, that is, the wear damage of the feeding blade 25b of the discharge screw 25, enables the replacement frequency to be reduced. The reduction in the replacement frequency reduces the number of times the reduction furnace 10 is stopped and remarkably increases the operation efficiency. In addition, suppressing the wear damage of the discharge screw 25 in this way eliminates the need to reduce the drive speed of the discharge screw 25 in order to avoid the wear damage, thereby increasing the discharge speed and improving the operation efficiency. Make it possible to improve.

(A-2) Concave part Early detection of the concave part, which is a part recessed on the surface of the hearth 18 than the other parts, can greatly contribute to maintaining good operation of the reduction furnace 10. If there is a deep recess on the surface of the hearth 18, for example, the reduced iron raw material 2 is likely to be deposited there, thereby forming a multi-layered state and reducing the reduction of the raw material in the lower layer. Although there is a risk of lowering, the monitoring can prevent the decrease in productivity.

(B) Temperature of the surface of the hearth 18 Monitoring of the temperature distribution and temperature change of the surface of the hearth 18 is also very important in properly maintaining and managing the surface of the hearth 18. Specifically, it is as follows.

(B-1) Temperature distribution When the surface temperature of the hearth 18 detected over the entire circumference varies significantly depending on the location, i) friction caused by contact between the discharge device 14 and the surface of the hearth 18 It is conceivable that heat is generated significantly, and ii) changes in luminance and emissivity (that is, changes in color) due to local fluctuations in the components of the hearth 18. Therefore, informing the user of the variation in the temperature distribution and the like at an early stage helps to take precautions in anticipation of the occurrence of an abnormality.

(B-2) Temperature change When there is a significant change in the temperature of the surface of the hearth 18, the cause is i) fluctuation of the charged state of the reduced iron raw material 2 ii) fluctuation of the reaction state (for example, reaction) Speed fluctuation). Therefore, to know the change in the surface temperature of the hearth 18 at an early stage, for i), it is possible to check the charging state early, adjust the supply equipment in advance, or check and correct the unevenness of the charging state. For ii), confirmation of the heating operation state in the reduction furnace 10 can be promoted. This temperature change can be provided, for example, when the monitoring image creating unit 52 stores information detected in the past and compares it with currently input information.

  The fluctuation of the charging state can be monitored by providing a height information detector equivalent to the distance sensor 42 in a region downstream of the charging position, for example. However, unlike this monitoring target area Amt, this area has significant powder scattering, and high-precision detection and monitoring cannot be expected. In other words, as described above, the region on the downstream side of the discharge position and the upstream side of the loading position (preferably the region on the upstream side of the replenishment position when the floor covering material is replenished) is the monitoring target region. Setting to Amt makes it possible to monitor the surface of the hearth 18 with high accuracy.

  Furthermore, various automatic controls can be executed based on the monitoring information output by the hearth monitoring device. For example, when the unevenness of the surface of the hearth 18 is remarkable, the control for reducing the rotational speed of the discharge screw 25, the control for automatically adjusting the height of the discharge screw 25, and the driving speed of the leveling devices 13 and 17 are set. It is also possible to perform control such as raising.

2 Reduced iron raw material 10 Reduction furnace 11 Floor covering material 12 Raw material charging device 14 Discharge device 16 Floor covering material replenishing device 18 Hearth 25 Discharge screw 28 Burner (heater)
40 detector 42 distance sensor (height information detector)
44 Temperature sensor (temperature information detector)
DESCRIPTION OF SYMBOLS 50 Calculation control part 52 Monitoring image preparation part 54 Warning necessity judgment part 60 Output part 62 Image display part 64 Warning output part

Claims (7)

An apparatus for producing reduced iron by heat treating a reduced iron raw material containing a carbonaceous reducing agent and iron oxide,
A reduction furnace including a hearth that moves in the rotation direction and a heater that generates reduced iron by heating reduced iron raw material on the hearth;
A raw material charging device for charging reduced iron raw material onto the hearth at a charging position set on the hearth;
The reduced iron generated by heating the reduced iron raw material by the heater on the hearth at a discharge position away from the charging position on the hearth in the moving direction of the hearth. A discharge device for sending and discharging in a direction crossing the direction;
A monitoring device for monitoring the state of the surface of the hearth in the monitoring target region downstream of the discharge position and upstream of the charging position with respect to the movement direction of the hearth,
The monitoring device is configured to detect information related to a state of the surface of the hearth in the monitoring target area, and to accumulate information related to a state of the surface of the hearth detected by the detection unit. A monitoring information creation unit that creates monitoring information about the surface state of the hearth over the entire circumference of the floor, and an output unit that outputs the monitoring information created by the information creation unit. manufacturing device.   The reduced iron manufacturing apparatus according to claim 1, wherein the monitoring information creation unit creates a monitoring image representing a distribution of the information based on information detected by the detection unit. apparatus.   The reduced iron manufacturing apparatus according to claim 1, wherein the detection unit includes a height information detector that detects information about the height of the surface as information on the surface of the hearth. apparatus.   It is a manufacturing apparatus of the reduced iron of Claim 3, Comprising: The said information preparation part for monitoring shows the image which shows the height distribution of the surface of the said hearth based on the information about the height detected by the said detection part. Reduced iron manufacturing equipment to be created.   The reduced iron manufacturing apparatus according to claim 1, wherein the detection unit includes a temperature detector that detects information about a temperature of the surface as information on the surface of the hearth.   6. The apparatus for producing reduced iron according to claim 5, wherein the monitoring information creation unit creates an image indicating a temperature distribution of the surface of the hearth based on information about the temperature detected by the detection unit. , Reduced iron production equipment.   It is a manufacturing apparatus of the reduced iron in any one of Claims 1-6, Comprising: The said monitoring apparatus is a case where the information regarding the surface state of the said hearth detected by the said detection part exceeds the preset allowable range An apparatus for producing reduced iron, further comprising: a warning necessity determination unit that generates a warning command and a warning output unit that receives the warning command and outputs a warning.

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