JP2020125513A - Control method and control device - Google Patents

Abstract

To provide a method and a device for controlling a reduction furnace so as to suppress scattering loss of agglomerated materials.SOLUTION: A control device 10 includes: an imaging device 100 that sequentially images agglomerated materials discharged from a rotary hearth furnace 300 to generate a captured image; and an arithmetic processing device 200 that controls the rotating hearth furnace 300 based on the captured image generated by the imaging device 100. The arithmetic processing device 200 includes: an image processing section 203 that performs image processing on the captured image generated by the imaging device 100 to calculate particle sizes of the agglomerated materials; a scattering loss calculation section 209 that calculates a scattering loss of the agglomerated materials in the next process from the calculated particle sizes; and a temperature control section 210 that determines a temperature at which the scattering loss is equal to or less than a certain value from a correlation between a ratio of the agglomerated materials discharged from the rotary hearth furnace 300 and having a particle size equal to or less than a predetermined value and a mean furnace temperature of the rotary hearth furnace 300, and sets the rotary hearth furnace 300 at the temperature.SELECTED DRAWING: Figure 1

Description

The present invention relates to a reduction furnace control method and a control apparatus.

As one of the processes for producing reduced iron, powdered iron ore and carbonaceous materials such as powdered coal and coke are mixed to form agglomerates such as pellets and briquettes, There is a method of charging solidified iron into a reduction furnace such as a rotary hearth furnace and heating it to a high temperature to reduce iron oxide in iron ore to obtain solid metallic iron. A burner is generally used to heat a reduction furnace such as a rotary hearth furnace, and the agglomerates that are the raw material of the reduced iron are transferred from the outside by heat radiated from the burner and the furnace wall of the reduction furnace. Be heated. Then, the agglomerate is discharged outside the furnace and sent to the melting step.

If the agglomerates are crushed and the particle size becomes several mm or less, they are sucked by the dust collector and the yield is deteriorated. Therefore, a technique for accurately measuring the particle size distribution of the agglomerates is required. Patent Document 1 discloses a technique capable of simultaneously determining the particle size and temperature of an agglomerate from a photographed image of the agglomerate discharged from a reduction furnace.

JP, 2017-72433, A

Of the agglomerates transported from the reduction furnace to the next melting step, the proportion that does not stay in the melting furnace and contributes to the steel output, such as by being scattered and collected by a dust collector, is called scattering loss. .. When the scattering loss increases, the yield deteriorates, and the operation of the reduction furnace becomes unstable. Therefore, a technology that stabilizes the operation is required.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method and an apparatus for controlling a reduction furnace so as to suppress scattering loss of agglomerates.

A reduction furnace control method of the present invention includes an imaging step of sequentially imaging agglomerates discharged from the reduction furnace to generate a captured image, and performing image processing on the captured image generated in the imaging step to perform the image processing. A particle size calculation step of calculating the particle size of the agglomerate, a dispersion loss calculation step of calculating the particle dispersion loss of the agglomerate in the next step from the particle size calculated in the particle size calculation step, and discharge from the reduction furnace From the correlation between the ratio of the agglomerates of which the particle size is less than or equal to a predetermined value among the agglomerated products and the average furnace temperature of the reducing furnace, the temperature at which the scattering loss is a certain value or less is obtained, and the reducing furnace Is set to the temperature.

A control device for a reduction furnace of the present invention includes an imaging device that sequentially captures agglomerates discharged from the reduction furnace to generate a captured image, and the reduction furnace based on the captured image generated by the imaging device. And an arithmetic processing unit for controlling. The arithmetic processing device performs a next step from a particle size calculation unit that performs image processing on the captured image generated by the imaging device to calculate the particle size of the agglomerate, and the particle size calculated by the particle size calculation unit. In the dispersion loss calculation unit for calculating the dispersion loss of the agglomerate in, the proportion of the agglomerates of the agglomerates discharged from the reduction furnace of the particle size of a predetermined value or less, and the reduction furnace of A temperature control unit that determines a temperature at which the scattering loss is equal to or less than a certain value from a correlation with an average furnace temperature and sets the reducing furnace to the temperature.

According to the present invention, in order to reduce the scattering loss of the agglomerate discharged from the reduction furnace, by setting the temperature of the reduction furnace according to the ratio of the agglomerates having a particle size of a predetermined value or less, reduction It is possible to stabilize the operation of the furnace.

It is a figure which shows typically the whole structure of the control apparatus which concerns on embodiment of this invention. It is a schematic diagram for explaining the installation state of the imaging device of the present embodiment. It is a figure which shows an example of the picked-up image produced|generated by the imaging device. It is a functional block diagram of an image processing part with which the arithmetic processing unit of this embodiment is provided. It is a flowchart which shows the control method of the rotary hearth furnace performed by the control apparatus of this embodiment. It is a graph which shows the correlation with the amount of fluctuations from the standard of powder loss with a predetermined particle size or less, and scattering loss. It is a table which shows the correlation of the average furnace temperature of a rotary hearth furnace, and the powder ratio below a predetermined particle size.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same or similar components will be denoted by the same reference symbols, without redundant description.

<Overall configuration of control device>
First, the configuration of the control device 10 according to the embodiment of the present invention will be described. FIG. 1 is a diagram schematically showing an overall configuration of a control device 10 according to this embodiment.

The control device 10 is a device that obtains the scattering loss from the particle size of the agglomerate discharged from the reducing furnace and controls the temperature of the reducing furnace based on the obtained scattering loss. As shown in FIG. 1, the control device 10 mainly includes an imaging device 100 and an arithmetic processing device 200.

Here, the reducing furnace is an agglomerate such as pellets or briquettes formed by mixing powdery iron ore (iron oxide) and carbonaceous material (that is, reducing agent) such as powdery coal or coke. It is a facility for producing solid metallic iron (that is, reduced iron) by reducing the iron oxide in the iron ore by charging the agglomerate to a high temperature. In this embodiment, a rotary hearth furnace (RHF) is taken as an example of the reduction furnace.

The imaging device 100 is installed in the vicinity of the out-of-furnace outlet 301 of the rotary hearth furnace 300, and is an apparatus that images the agglomerates falling inside the out-of-hearth outlet 301 and generates a captured image.

The imaging device 100 includes various optical elements such as a lens and an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). Here, the imaging device 100 may be capable of generating a still image or may be capable of generating a moving image. Further, the imaging device 100 may be capable of capturing a monochrome image or may be capable of capturing a color image. When using an image pickup device capable of picking up a color image, a one-channel image may be generated. That is, as the means for generating the captured image, only one of the R, G, and B components of the RGB components may be used, or the RGB color space is converted to the YCbCr color space, and only the Y component is generated. You may use it.

The imaging device 100 is controlled by the arithmetic processing device 200, and imaging is performed by outputting a trigger signal for imaging at a predetermined frame rate from the arithmetic processing device 200. The imaging device 100 images the thermal radiation of the agglomerates falling inside the out-of-furnace outlet 301 of the rotary hearth furnace 300 in response to the trigger signal output from the arithmetic processing device 200 to generate a captured image, The generated captured image is output to the arithmetic processing device 200.

FIG. 2 is a schematic diagram for explaining the installation state of the image pickup apparatus 100, and FIG. 3 is an example of a captured image generated by the image pickup apparatus 100. As shown in FIG. 2, the imaging device 100 is installed near an observation window 302 for observing the state of the outside-furnace outlet 301. Inside the outside-furnace outlet 301, the agglomerate 1 discharged from the rotary hearth furnace 300 is constantly dropping. The imaging device 100 is installed, for example, at a position separated from the observation window 302 by about 2 m, and sequentially images the thermal radiation of the agglomerate 1 falling inside the outside of the furnace outlet 301 through the observation window 302, A captured image (heat radiation image) as shown in FIG. 3 is generated. Here, the temperature of the agglomerate 1 in the outside-furnace outlet 301 is about 800°C to 1000°C.

As shown in FIG. 3, the thermal radiation image generated by the imaging device 100 is inside the field of view corresponding to the observation window 302 (in FIG. 3, a substantially circular field of view with a diameter of about 160 mm) of the outside-furnace outlet 301. The agglomerate 1 falling inside is reflected. In such a thermal radiation image, the agglomerate 1 having a higher temperature is shown in white in the thermal radiation image, and the agglomerate 1 having a lower temperature is shown in black in the thermal radiation image.

As shown in FIG. 1, the arithmetic processing device 200 includes an imaging control unit 201, an image processing unit 203, a display control unit 205, a storage unit 207, a scattering loss calculation unit 209, and a temperature control unit 210. Prepare The arithmetic processing device 200 includes, for example, a CPU (Central Processing Unit), and the CPU according to various programs stored in the storage unit 207, the imaging control unit 201, the image processing unit 203, the display control unit 205, the scattering loss calculation. The respective functions of the unit 209 and the temperature control unit 210 are controlled.

The imaging control unit 201 controls the imaging process performed by the imaging device 100. More specifically, the imaging control unit 201 causes the imaging device 100 to perform imaging at a predetermined frame rate when imaging the inside of the furnace outlet 301 of the rotary hearth furnace 300. The trigger signal of is transmitted.

The image processing unit 203 acquires a captured image of the agglomerate 1 from the imaging device 100, performs image processing on the acquired captured image to detect the agglomerate 1, and detects the grain size of the detected agglomerate 1. Calculate (particle size distribution). Detailed functions of the image processing unit 203 will be described later (see FIG. 4).

The display control unit 205 displays the captured image generated by the imaging device 100, the processing result by the image processing unit 203, the calculation result by the scattering loss calculation unit 209, and the information about the temperature control by the temperature control unit 210, on the display unit 206. To be displayed.

The display unit 206 includes a display such as a liquid crystal display (LCD), a plasma display, or an organic electroluminescence (EL) display, and under the control of the display control unit 205, a captured image generated by the imaging device 100 and calculation. The processing result of the processing device 200 is displayed.

The storage unit 207 includes a ROM (Read Only Memory) and a RAM (Random Access Memory). The ROM stores various programs such as a control processing program (see FIG. 5) executed by the CPU and data necessary for executing these programs. Various programs and data stored in the ROM are loaded into the RAM and executed.

The storage unit 207 may include a magnetic memory such as a hard disk drive (HDD) or an optical memory such as an optical disk. Alternatively, various programs and data may be stored in a computer-readable recording medium that is removable from the arithmetic processing device 200. Alternatively, various programs executed by the arithmetic processing device 200 may be received via a communication network.

The scattering loss calculation unit 209 calculates the scattering loss of the agglomerate 1 in the next step (melting step) from the particle size (particle size distribution) of the agglomerate 1 calculated by the image processing unit 203. The calculation of the scattering loss will be described later (see FIGS. 5 and 6).

The temperature control unit 210 correlates the powder ratio (%) of a predetermined particle size or less and the average furnace temperature (° C.) of the rotary hearth furnace 300 (FIG. 7) so that the scattering loss, which adversely affects the yield, becomes a certain value or less. ), the temperature corresponding to the powder ratio (%) of the predetermined particle size or less, which is correlated with the scattering loss, is obtained, and the temperature in the rotary hearth furnace 300 is set to the temperature. The powder ratio (%) of the predetermined particle size or less is a ratio of the agglomerates 1 having a particle size of a predetermined value or less to all the agglomerates 1 detected by the image processing unit 203. The temperature control by the temperature control unit 210 will be described later (see FIGS. 5 and 7).

The arithmetic processing device 200 may be configured by general-purpose hardware, or may be configured by hardware specialized for each function of the arithmetic processing device 200. For example, the function of the image processing unit 203 may be configured by hardware such as an application specific integrated circuit (ASIC).

Next, the function of the image processing unit 203 will be described with reference to FIG. FIG. 4 is a functional block diagram of the image processing unit 203.

The image processing unit 203 has a function of calculating the grain size of the agglomerate 1 from the captured image of the agglomerate 1 generated by the imaging device 100, and as shown in FIG. 4, the preprocessing unit 211 and the filter process. The image generation unit 213, the linear function calculation unit 215, the threshold value determination unit 217, the binarized image generation unit 219, the composite image generation unit 221, the labeling unit 223, and the granularity calculation unit 225 are included. In the present embodiment, the method disclosed in Patent Document 1 is adopted as the method of calculating the particle size of the agglomerate 1 executed by the image processing unit 203.

The pre-processing unit 211 performs various pre-processings on a captured image (thermal radiation image) of the agglomerate 1 that is falling from the outside of the furnace 301, which is output from the imaging device 100, as necessary. Give. An example of such preprocessing is image reduction processing for reducing a captured image to a predetermined image size. The degree of reduction is not particularly limited as long as the powdery agglomerate 1 is present as at least one pixel in the captured image after reduction. The pre-processing unit 211 can arbitrarily set the reduction ratio of the captured image, but can perform image reduction processing that reduces the captured image to 1/3 both vertically and horizontally, for example. By executing such image reduction processing, it is possible to further reduce the calculation time of the following image processing.

The filtered image generation unit 213 includes a plurality of normalized Laplacian-Gaussian filters (hereinafter, referred to as “normalized”) with respect to the captured image output from the image capturing apparatus 100 or the pre-processed captured image. Each of these is referred to as a “modified LoG filter”) to generate a plurality of filtered images.

The functional form of the normalized LoG filter is given by the following equation (1).

The filtered image generation unit 213 sets the coordinates of the center to (0, 0), and sets the weight of the pixel separated by (i, j) pixels from the center to (x, y)=(i, j) in Expression (1). A filter having a value obtained by substituting is created, and the filter processing is performed by multiplying the thermal radiation image by the filter.

Specifically, in this filter processing, a thermal radiation image represented by luminance is set to f(x, y), f(x, y) at coordinates (x, y) is multiplied by φ(0, 0), and coordinates are set. The value obtained by multiplying f(x+i, y+j) at (x+i, y+i) by φ(i, j) is defined as the sum of the parameters i, j. That is, by calculating g(x, y) represented by the following equation (2), a thermal radiation image after the normalized LoG filter is applied can be obtained.

A plurality of normalized LoG filters having different standard deviations σ are used for detecting agglomerates 1 having a first diameter or less (that is, agglomerates 1 having a small particle size 1). And a second normalized LoG filter group (that is, medium to large particle size agglomerates 1) used for detecting agglomerates 1 having a second diameter or more. (Normalized LoG filter group) for detection. The specific values of the first diameter and the second diameter may be appropriately set by analyzing the particle size distribution of the agglomerate 1 produced in the rotary hearth furnace 300 by a known measurement method in advance. Good.

When the first diameter is 3 mm (about 1/5 or less of the average particle size of the agglomerate 1), for the first normalized LoG filter group, for example, σ=1/3, 2/3, 1, It is possible to use four types of normalized LoG filters in which a value of 2 is set. When the second diameter is 8 mm, for example, four types of normalized LoG filters in which the values of σ=3, 4,..., 6 are set are used as the second normalized LoG filter group. it can.

Hereinafter, the filtered image group generated by the action of the first normalized LoG filter group will be referred to as a first filtered image group, and the filtered image group generated by the action of the second normalized LoG filter group will be referred to as a second filtered image group. This will be referred to as a filtered image group.

The linear function calculation unit 215 calculates a linear function that is used by the threshold value determination unit 217 to be described later to determine the threshold value when binarizing the filtered image. This linear function is a linear function that represents the correspondence relationship between the average luminance value of the first filtered image group and the average luminance value of the second filtered image group. More specifically, when the average brightness value of the first filtered image group is X and the average brightness value of the second filtered image group is Y, the linear function is a combination of (X,Y) in the XY plane. Is obtained by linearly approximating a set of lower limit values of Y at each X position by a known method such as the least square method (see FIG. 7 of Patent Document 1). The data of the linear function (Y=AX+B) calculated in this way is stored in the storage unit 207.

Note that the linear function calculation process may be performed at least once as long as the imaging environment of the agglomerate 1 by the imaging device 100 does not change, and need not be executed each time a captured image is generated by the imaging device 100. Absent.

The threshold value determination unit 217 determines a threshold value (first threshold value) for binarizing the first filtered image group, and also based on the linear function calculated by the linear function calculation unit 215, the second filtered image. A threshold value (second threshold value) for binarizing the group is determined.

Specifically, the threshold value determination unit 217 sets a threshold value (first threshold value) for detecting the agglomerates 1 having a first diameter or less to a predetermined fixed value with respect to the average luminance value of the first filtered image group. The value is multiplied by. More specifically, the threshold value determination unit 217 also detects the agglomerates 1 having a brightness of X _r or less in consideration of the brightness variation of the agglomerates 1 with respect to the average brightness value X _r of the first filtered image group. As described above, the first threshold value is obtained by multiplying by a certain value (for example, 0.5) included in the range of 0.4 to 0.6.

The reason why the first threshold value is obtained by multiplying the average luminance value X _r by a certain fixed value is that the agglomerates 1 having a small particle size included in the first filtered image group have less temperature unevenness, This is because binarization is considered to be easy.

In addition, the threshold value determining unit 217 uses the threshold value (second threshold value) for detecting the agglomerate 1 having the second diameter or more as the average brightness to the linear function (Y=AX+B) calculated by the linear function calculating unit 215. The value Y _r is obtained by substituting the value X _r . As described above, the second threshold value is not a fixed value, but a value that varies according to the average luminance value of the first filtered image group. This makes it possible to set the threshold value for detecting the agglomerates 1 having a medium to large particle size to a value at which neither undetected nor overdetected occurs.

The binarized image generation unit 219 binarizes each image included in the first filtered image group using the first threshold to generate a binarized image, and uses the second threshold to generate the second binned image. Each image included in the filtered image group is binarized to generate a binarized image.

The composite image generation unit 221 combines the plurality of binarized images generated by the binarized image generation unit 219 to generate a composite binarized image.

In addition, in the binarized image obtained from the first filtered image group, there may be a case where the outer shape of the agglomerate 1 having a medium to large particle size remains. In this case, the combined image generation unit 221 first separately combines the binarized image obtained from the first filtered image and the binarized image obtained from the second filtered image, and then the first filtered image. The synthesized image obtained from the processed image minus the synthesized image obtained from the second filtered image (difference image) is used as the synthesized image of the first filtered image used for the final synthesized image. May be. By using such a difference image, it becomes possible to detect the agglomerate 1 having a small particle size more accurately.

The labeling unit 223 refers to the composite binarized image generated by the composite image generation unit 221, and performs a labeling process on a portion having a brightness value of 1, to thereby generate agglomerates 1 included in the binarized image. To identify and detect. The labeling process executed by the labeling unit 223 is not particularly limited, and a known labeling process can be applied.

The particle size calculator 225 calculates the particle size of each of the agglomerates 1 detected by the labeling unit 223. As the particle size of the agglomerate 1, for example, the area S of the agglomerate 1, the peripheral length (the length along the outer shape of the agglomerate 1) L, the equivalent diameter (0.5×(S/π)), The length of the major axis, the length of the minor axis and the like can be mentioned. The length of the major axis is the length of the major axis in the corresponding ellipse of the agglomerate 1 (the ellipse having the same area as the agglomerate 1 and having the same first and second moments), and the length of the minor axis is It is the length of the minor axis in the equivalent ellipse.

<Flow of control method>
Next, a flow of a control method executed by the control device 10 will be described with reference to FIGS. FIG. 5 is a flowchart of the control method executed by the control device 10.

First, the image capturing apparatus 100 sequentially captures images of the agglomerates 1 falling inside the out-of-furnace outlet 301 of the rotary hearth furnace 300 under the control of the image capturing control unit 201 to generate captured images (step S101). , And outputs the generated captured image to the arithmetic processing device 200.

Next, the preprocessing unit 211 acquires the captured image generated by the imaging device 100, and performs preprocessing such as reduction processing on the acquired captured image as necessary (step S103).

Next, the filtered image generation unit 213 applies a plurality of normalized LoG filters having different standard deviations σ to the captured image obtained in step S101 or the captured image after preprocessing to perform a plurality of filter processes. An image (first filter processed image group and second filter processed image group) is generated (step S105).

The linear function calculation unit 215 uses the linear function used when the threshold value determination unit 217 calculates the second threshold value using the first filtered image group and the second filtered image group generated by the filtered image generation unit 213. To calculate. The threshold value determination unit 217 calculates the average luminance value of the first filtered image group, and multiplies the average luminance value by a predetermined fixed value to binarize the first filtered image group. The threshold is determined, and the second threshold for binarizing the second filtered image group is determined using the linear function obtained by the linear function calculation unit 215 and the average luminance value of the first filtered image group. (Step S107).

Next, the binarized image generation unit 219 binarizes each image included in the first filtered image group to generate a binarized image using the first threshold value, and uses the second threshold value. Each image included in the second filtered image group is binarized to generate a binarized image (step S109).

Next, the synthetic image generation unit 221 synthesizes the respective binarized images generated by the binarized image generation unit 219 to generate a synthetic binarized image (step S111).

Next, the labeling unit 223 detects the agglomerate 1 by performing a labeling process on the site having the brightness value of 1 in the composite binarized image (step S113).

Next, the particle size calculation unit 225 calculates the particle size (particle size distribution) of the agglomerate 1 detected by the labeling unit 223 (step S115).

Next, the scattering loss calculation unit 209 calculates the scattering loss in the next step (melting step) of the agglomerate 1 from the particle size calculated in step S115 (step S117). Specifically, the storage unit 207 stores the data of the calibration curve indicating the relationship between the particle size of the agglomerate and the scattering loss, and the scattering loss calculation unit 209 uses the calibration curve to calculate the particle size calculated in step S115. To calculate the scattering loss.

FIG. 6 shows the result of plotting the correlation between the powder ratio (%) of a predetermined particle size or less and the Δ scattering loss (%). In FIG. 6, the powder ratio (%) equal to or smaller than the predetermined particle diameter is such that the particle diameter is equal to or smaller than the predetermined particle diameter (first diameter or less) with respect to the amount (number) of all the agglomerates 1 detected by the labeling unit 223. It is the ratio of the amount (number) of agglomerates 1. The Δscattering loss (%) is the amount of fluctuation from the reference (%) of the scattering loss (the amount of fluctuation up to +1.5 (%) in FIG. 6). It can be seen from FIG. 6 that the Δ scattering loss increases as the proportion of powder having a predetermined particle size or less increases. From this, it can be seen that there is a clear correlation between the powder ratio below the predetermined particle size and the Δ scattering loss. Therefore, in order to reduce the Δscattering loss and improve the yield, it is understood that the operation should be controlled so that the proportion of powder having a predetermined particle size or less is reduced. Note that once the data of the calibration curve shown in FIG. 6 has been created, it is not necessary to obtain the scattering loss each time the operation is controlled, so S117 can be omitted.

Next, the temperature control unit 210 obtains a powder ratio (%) of a predetermined particle size or less corresponding to a target dispersion loss so that the scattering loss becomes a certain value or less. From the correlation with the average furnace temperature (° C.) of the rotary hearth furnace 300, the temperature corresponding to the obtained powder ratio (%) of the predetermined particle size or less is obtained, and the temperature inside the rotary hearth furnace 300 is set to the temperature (step). S119).

FIG. 7 shows the result of investigating the correlation between the powder ratio (%) of a predetermined particle diameter or less (first diameter or less) and the average furnace temperature (° C.) of the rotary hearth furnace 300. Here, the average furnace temperature (° C.) is an average value of the atmospheric temperature of the rotary hearth furnace 300 measured by a thermometer such as a thermocouple thermometer installed in the rotary hearth furnace 300. The data shown in FIG. 7 is stored in the storage unit 207. From FIG. 7, for example, if the average furnace temperature of the rotary hearth furnace 300 is set to 1280° C. or higher, the proportion of powder having a predetermined particle size or less becomes 4% or less, and from FIG. 6, Δ scattering loss becomes 0.5% or less. Can be suppressed. Therefore, for example, the temperature control unit 210 sets the temperature of the rotary hearth furnace 300 to 1280°C. Since raising the temperature of the rotary hearth furnace 300 directly leads to an increase in production cost, it is not preferable to raise the temperature excessively, but in this way, from the measured particle size distribution, it is possible to suppress the scattering loss that deteriorates the yield. By finding the optimum temperature condition, it becomes possible to control to the optimum operating condition.

As described above, according to the present embodiment, the arithmetic processing device 200 obtains the grain size of the agglomerate 1 from the captured image obtained by photographing the agglomerate 1 with the imaging device 100, and the scattering loss from the obtained grain size. Is calculated and the furnace temperature is controlled so as to suppress the scattering loss. As a result, it is possible to realize stable operation in which scattering loss is suppressed without excessively raising the temperature of the rotary hearth furnace 300.

The description content in the present embodiment can be appropriately changed without departing from the spirit of the present invention.
For example, in the above-described embodiment, the normalized LoG filter is applied to the captured image to generate a plurality of filtered images, but the type of filter to be applied to the captured image is not particularly limited.
Further, in the above-described embodiment, the first diameter required for calculating the scattering loss is set to about 1/5 of the average particle size of the agglomerate 1, but the size of the first diameter is not particularly limited. For example, the first diameter may be about 1/10 of the average particle size of the agglomerate 1.

1 agglomerate 10 control device 100 imaging device 200 arithmetic processing device 201 imaging control unit 203 image processing unit 205 display control unit 206 display unit 207 storage unit 209 scattering loss calculation unit 210 temperature control unit 211 preprocessing unit 213 filter image generation Part 215 Linear function calculation part 217 Threshold value determination part 219 Binary image generation part 221 Composite image generation part 223 Labeling part 225 Particle size calculation part 300 Rotating hearth furnace 301 Outer discharge port 302 Observation window

Claims (5)

An imaging step of sequentially imaging the agglomerates discharged from the reduction furnace to generate a captured image,
A particle size calculation step of performing image processing on the captured image generated in the imaging step to calculate the particle size of the agglomerate;
From the particle size calculated in the particle size calculation step, a scattering loss calculation step of calculating the scattering loss of the agglomerate in the next step,
From the correlation between the proportion of agglomerates of which the particle size is equal to or less than a predetermined value among the agglomerates discharged from the reduction furnace, and the average furnace temperature of the reduction furnace, the temperature at which the scattering loss becomes a certain value or less And a control step of setting the reducing furnace to the temperature,
A method of controlling the reduction furnace, comprising: The particle size calculating step calculates at least one of an area, a peripheral length, an equivalent diameter, a length of a major axis, and a length of a minor axis of the agglomerate as the particle size. Control method. The control method according to claim 1 or 2, wherein a ratio of the agglomerates having a particle size equal to or smaller than a predetermined value is a ratio at which the particle sizes are 1/5 or less of an average particle size of the agglomerates. The control method is
A filtered image generation step of performing a filter process on the captured image to generate a filtered image;
A binarized image generating step of binarizing the filtered image to generate a binarized image;
A detection step of detecting the agglomerate from the binarized image;
Equipped with
The particle size calculation step,
The control method according to claim 1, wherein the particle size of the agglomerate detected in the detecting step is calculated. An imaging device that sequentially captures images of the agglomerates discharged from the reduction furnace and generates a captured image,
An arithmetic processing unit that controls the reduction furnace based on the captured image generated by the imaging device,
The arithmetic processing unit,
A particle size calculator that calculates the particle size of the agglomerate by performing image processing on the captured image generated by the imaging device,
From the particle size calculated by the particle size calculation unit, a scattering loss calculation unit that calculates the scattering loss of the agglomerate in the next step,
From the correlation between the proportion of agglomerates of which the particle size is equal to or less than a predetermined value among the agglomerates discharged from the reduction furnace, and the average furnace temperature of the reduction furnace, the temperature at which the scattering loss becomes a certain value or less Obtained, a temperature control unit for setting the reduction furnace to the temperature,
A control device for the reduction furnace, comprising:

Images