Particle dimension measurement system and method, and crushing system

Abstract

This particle dimension measurement system comprises a calculator configured to: acquire surface shape measurement data representing surface shapes of crushed products from a crusher; determine, through image processing, the dimensions of a plurality of particles appearing on the surfaces of the crushed products within a predetermined analysis range from the surface shape measurement data; sort the plurality of particles in descending order of the dimensions to define particles included in the top β% as large lumps; obtain the average value of the dimensions of the large lumps as a large-lump diameter; and output the large-lump diameter, wherein β is a predetermined value of 0.00001-30.

Description

Particle size measurement system and method, and crushing system

[0001] The present disclosure relates to a technique for measuring the particle size of crushed products from a crusher that controls the particle size of the crushed products according to the size of a crushing gap.

[0002] Conventionally, when generating a particle size distribution of crushed products crushed by a crusher, the crushed products are sieved through a plurality of test sieves having different openings, the frequency for each particle size category of the crushed products is measured based on the mass of the residue on each sieve, and the particle size distribution of the crushed products is generated using these frequencies. In recent years, in-line measurement of particle size distribution of crushed products using image processing has been proposed. Patent Document 1 discloses a technique of in-line measuring the particle size distribution state of crushed products using image processing to produce crushed products having a particle size distribution suitable for the purpose.

[0003] Patent Document 1 describes that all or part of the crushed products carried out from the crusher is imaged by an optical system means, the particle size and particle size distribution of the crushed products are calculated from the captured image by an image analysis means, and a raw material supply means or a crushing means is controlled so that a predetermined particle size and a particle size distribution centered on the particle size fall within an allowable range. This image analysis means binarizes the captured image, recognizes particles from closed curves that reproduce particle contours on the image, measures the projected area of each particle on the image, and calculates the particle size and particle size distribution by taking the particle diameter as the equivalent circle diameter having an area equal to the projected area.

[0004] Japanese Unexamined Patent Application Publication No. 2003-10726

[0005] Typically, crushing systems consist of multiple stages of crushers, such as primary, secondary, and tertiary crushers. The crushed material is transported by a conveyor to the next stage of crusher, where it is further crushed to produce finer crushed material. In crushers where the crushing gap has become larger than the set value due to wear or other reasons, the average particle size of the crushed material may become larger than the value corresponding to the set value of the crushing gap, the proportion of large chunks in the crushed material may increase, or the size of the largest chunks in the crushed material may increase. This can lead to overloading of the next stage of crusher that crushes the material, or stagnation in the conveyor that transports the crushed material to the next stage of crusher, potentially causing instability in the operation of the crushing system.

[0006] The inventors of this application have found that the dimensions of the largest chunks in the crushed product respond to the OSS (Open Side Set) of the crusher, and that changes in the OSS of the crusher due to wear of the crusher can be inferred from changes in the dimensions of the largest chunks in the crushed product.

[0007] This disclosure is made in view of the above circumstances, and its purpose is to provide a technology that can detect changes in the size of large chunks contained in the crushed product of a crusher, thereby contributing to the stable operation of a crushing system including a crusher.

[0008] A particle size measurement system according to one aspect of the present disclosure includes a calculator, the calculator acquires surface shape measurement data representing the surface shape of the crushed product of a crusher, determines the dimensions of a plurality of particles appearing on the surface of the crushed product within a predetermined analysis range from the surface shape measurement data by image processing, sorts the plurality of particles in descending order of their dimensions and defines those included in the top β% as large clumps, determines the average value of the dimensions of the large clumps as the large clump diameter, and outputs the large clump diameter, where β is a predetermined value between 0.00001 and 30.

[0009] Furthermore, a particle size measurement system according to another aspect of the present disclosure includes a calculator, the calculator acquires surface shape measurement data representing the surface shape of the crushed product of a crusher, determines the dimensions of a plurality of particles appearing on the surface of the crushed product within a predetermined analysis range from the surface shape measurement data by image processing, defines those particles having a dimension of γ% or more of a predetermined OSS (Open Side Set) setting value of the crusher as large clumps, determines the average value of the dimensions of the large clumps as the large clump diameter, and outputs the large clump diameter, wherein γ is a predetermined value between 50 and 300.

[0010] A crushing system according to another aspect of the present disclosure comprises a crusher, a conveying conveyor for transporting the crushed product of the crusher, and the above-described particle size measurement system for determining the large clump diameter of the crushed product transported by the conveying conveyor.

[0011] A particle size measurement method according to one aspect of the present disclosure is a particle size measurement method performed by a calculator, comprising: acquiring surface shape measurement data representing the surface shape of a crushed product from a crusher; determining the dimensions of a plurality of particles appearing on the surface of the crushed product within a predetermined analysis range from the surface shape measurement data by image processing; sorting the plurality of particles in descending order of their dimensions, defining those included in the top β% as large clumps, determining the average value of the dimensions of the large clumps as the large clump diameter; and outputting the large clump diameter, wherein β is a predetermined value between 0.00001 and 30.

[0012] A particle size measurement method according to another aspect of the present disclosure is a particle size measurement method performed by a calculator, comprising: acquiring surface shape measurement data representing the surface shape of a crushed product of a crusher; determining the dimensions of a plurality of particles appearing on the surface of the crushed product within a predetermined analysis range from the surface shape measurement data by image processing; defining those particles having dimensions of γ% or more of a predetermined OSS setting value of the crusher as large clumps, determining the average value of the dimensions of the large clumps as the large clump diameter, and outputting the large clump diameter, wherein γ is a predetermined value between 50 and 300.

[0013] According to this disclosure, it is possible to detect changes in the size of large chunks contained in the crushed product of a crusher.

[0014] Figure 1 is a diagram showing the overall configuration of a particle size measurement system according to one embodiment of the present disclosure. Figure 2 is a block diagram showing the schematic configuration of a particle size measurement device. Figure 3 is a functional block diagram of the particle size measurement device. Figure 4 is a diagram showing the processing flow of the particle size measurement device. Figure 5 is a diagram showing the processing flow of the size measurement unit. Figure 6 is a diagram showing the configuration of particle size data. Figure 7 is a diagram showing the schematic configuration of a crushing system according to one embodiment of the present disclosure. Figure 8 is a diagram showing the configuration of the crusher in the crushing system.

[0015] The embodiments will be described in detail below with reference to the drawings. In the following, the same or corresponding elements are denoted by the same reference numerals throughout all the drawings, and redundant explanations are omitted.

[0016] [Particle Dimension Measurement System 1] Figure 1 is a diagram showing the schematic configuration of a particle dimension measurement system 1 according to one embodiment of the present disclosure. The particle dimension measurement system 1 shown in Figure 1 can measure the particle dimensions of crushed product 10 being transported by a transport conveyor 2 in line. The transport conveyor 2 includes a conveyor belt 22, a motor 23 that moves the conveyor belt 22 in the transport direction, and a speed sensor 24 that detects the speed of the conveyor belt 22. The speed sensor 24 may be a rotation speed sensor that detects the rotation speed of the motor 23. The crushed product 10 supplied through a chute falls onto the conveyor belt 22 which is traveling in the transport direction by the operation of the motor 23. A deposit layer of crushed product 10 (hereinafter referred to as the "crushed product layer 9") is formed on the conveyor belt 22.

[0017] The particle size measurement system 1 comprises a surface shape measuring device 3 and a particle size measurement device 4.

[0018] 《Surface Shape Measurement Device 3》 The surface shape measurement device 3 generates surface shape measurement data that represents the surface shape of the crushed product layer 9. The type of data is not particularly limited as long as it represents the surface shape of the crushed product layer 9, i.e., the unevenness. The surface shape measurement data may be, for example, cross-sectional profile data of the crushed product layer 9. The surface shape measurement data may be, for example, area image data obtained by imaging the crushed product layer 9 from above with an area scan camera. Furthermore, the surface shape measurement device 3 is not particularly limited, and a surface shape measurement device 3 is adopted according to the type of surface shape measurement data.

[0019] In this embodiment, cross-sectional profile data of the crushed product layer 9 is used as surface shape measurement data. In this case, the surface shape measuring device 3 consists of, for example, a line scan camera 31, a layer thickness measuring device 5, and a control panel 32.

[0020] The layer thickness measuring device 5 measures the thickness of the crushed product layer 9. The thickness of the crushed product layer 9 is the height from the surface of the conveyor belt 22 to the top surface of the crushed product layer 9. The layer thickness measuring device 5 may be, for example, a non-contact type laser distance sensor. The layer thickness measuring device 5 measures the thickness of the crushed product layer 9 at the same location as or in front of the imaging location of the line scan camera 31 of the surface shape measuring device 3. The layer thickness measuring device 5 can measure the surface height of the conveyor belt 22, the surface height of the crushed product layer 9, and the thickness of the crushed product layer 9. In this embodiment, the line scan camera 31 and the layer thickness measuring device 5 are described as separate devices, but the line scan camera 31 may also have the functions of the layer thickness measuring device 5.

[0021] The control panel 32 acquires the transport speed of the crushed product 10 by the conveyor belt 22 based on the detection value of the speed sensor 24 of the transport conveyor 2, and causes the line scan camera 31 to take images in accordance with the transport speed of the crushed product 10. However, the transport speed of the transport conveyor 2 may be a constant value, in which case the control panel 32 causes the line scan camera 31 to take images in accordance with the transport speed of the transport conveyor 2 which has been set in advance. The control panel 32 monitors the thickness of the crushed product layer 9 measured by the layer thickness measuring device 5, and causes the line scan camera 31 to take images when the thickness of the crushed product layer 9 is equal to or greater than a predetermined minimum layer thickness.

[0022] The line scan camera 31 images the surface of the crushed product layer 9 in a linear fashion, extending in the width direction perpendicular to the transport direction of the crushed product 10 (i.e., the depth direction of the paper in Figure 1). The line scan camera 31 images the surface of the crushed product layer 9, which is being transported in the transport direction by the conveyor belt 22, at predetermined time intervals corresponding to the transport speed of the crushed product 10. The control panel 32 outputs the linear image data obtained by the imaging to the particle size measuring device 4. By arranging and connecting the numerous linear image data (i.e., surface shape measurement data) obtained in this way in chronological order, area image data representing the surface shape of the crushed product layer 9 is obtained.

[0023] Alternatively, the surface shape measuring device 3 may consist of a three-dimensional profile measuring instrument, a layer thickness measuring device 5, and a control panel. The three-dimensional profile measuring instrument has a probe equipped with a light projector that irradiates the surface of the crushed product layer 9 with a laser in a linear manner extending in the width direction (i.e., the depth direction of the paper in Figure 1) perpendicular to the transport direction of the crushed product 10, and a light receiver that acquires reflected light. The profile measuring instrument obtains cross-sectional profile data perpendicular to the transport direction of the crushed product layer 9 by calculating the distance to the object to be measured based on the phase difference between the projected wavelength and the received wavelength. The control panel obtains the transport speed of the crushed product 10 by the conveyor belt 22 based on the detection value of the speed sensor 24 of the transport conveyor 2, and causes the profile measuring instrument to perform measurements in accordance with the transport speed of the crushed product 10. However, the transport speed of the transport conveyor 2 may be a constant value, in which case the control panel causes the profile measuring instrument to perform measurements in accordance with the transport speed of the transport conveyor 2 which has been given in advance. The profile measuring instrument measures the distance to the surface of the crushed product layer 9, which is being transported in the transport direction by the conveyor belt 22, at predetermined time intervals corresponding to the transport speed of the crushed product 10. The control panel outputs the cross-sectional profile data obtained by the measurement to the particle size measuring device 4. By arranging and connecting the numerous cross-sectional profile data (i.e., surface shape measurement data) obtained in this way in chronological order, area image data representing the surface shape of the crushed product layer 9 is obtained.

[0024] In the surface shape measuring device 3 illustrated above, the crushed product layer 9 moves in the conveying direction by the conveyor belt 2, so the camera or probe performs the measurement at a fixed position. However, the measurement may also be performed while the camera or probe moves while the crushed product layer 9 remains at a fixed position. In other words, the measurement can be performed in a manner in which the camera or probe moves relative to the crushed product layer 9.

[0025] Particle Dimension Measurement Device 4 The particle dimension measurement device 4 acquires surface shape measurement data generated by the surface shape measurement device 3 and measures the particle dimensions of the crushed product 10 based on the surface shape measurement data. The particle dimension measurement device 4 is connected to the surface shape measurement device 3 via wired or wireless communication. The particle dimension measurement device 4 may be located next to the surface shape measurement device 3, or it may be located in a remote location away from the surface shape measurement device 3. In addition, one particle dimension measurement device 4 may be provided for multiple surface shape measurement devices 3.

[0026] Figure 2 is a block diagram showing the schematic configuration of the particle size measuring device 4. As shown in Figure 2, the particle size measuring device 4 includes a calculator 400. Each of the functional units of the particle size measuring device 4, described later, may be composed of at least one calculator 400, or two or more of the multiple functional units may be composed of one calculator 400. The calculator 400 is a so-called computer that includes a processor 401, memory 402 such as ROM and RAM, and I / O 403. A memory 405, a display 407, and a surface shape measuring device 3 are connected to the calculator 400 via an interface 404.

[0027] Figure 3 is a functional block diagram of the particle size measuring device 4. As shown in Figure 3, the particle size measuring device 4 has functional units: a size measuring unit 41, a large clump diameter measuring unit 45, and a large clump diameter monitoring unit 46. The processing of these functional units will be explained below using the flowchart shown in Figure 4.

[0028] Dimensional Measurement Unit 41 The dimensional measurement unit 41 acquires surface shape measurement data generated by the surface shape measuring device 3 (step S1), and performs image processing of the surface shape measurement data to measure the dimensions of particles appearing in a target area on the surface of the crushed product layer 9 (step S2). The dimensions of the particles to be measured include, for example, the major axis diameter L and minor axis diameter W of the particle. The analysis method for measuring the major axis diameter L and minor axis diameter W of the particle from the image is not particularly limited and known methods can be used. Below, an example of the measurement method for the major axis diameter L and minor axis diameter W of the particle by the dimensional measurement unit 41 will be described, but the measurement method is not limited to this.

[0029] Figure 5 shows the processing flow of the dimensional measurement unit 41. As shown in Figure 5, the dimensional measurement unit 41 acquires surface shape measurement data from the surface shape measuring device 3. The surface shape measurement data is data obtained by continuously measuring the surface shape of the crushed product 10 in the direction of transport of the crushed product 10, and the measurement range is, for example, 100 m or more in the transport direction. The dimensional measurement unit 41 divides the surface shape measurement data into appropriate analysis ranges according to the processing capacity of the particle dimension measuring device 4. For example, one analysis range is an area with a length of about 1 m to 10 m in the transport direction.

[0030] The dimensional measurement unit 41 performs the following series of processes for each analysis range to determine the major axis diameter L and minor axis diameter W for each particle included in the analysis range, and generates particle dimensional data for the analysis range (step S3).

[0031] The dimensional measurement unit 41 extracts the analysis range from the surface shape measurement data, performs preprocessing such as removing the conveyor surface, and then performs three-dimensional processing on the surface shape measurement data to obtain a three-dimensional image of the surface of the crushed product layer 9. The dimensional measurement unit 41 performs image segmentation on the three-dimensional image of the surface of the crushed product layer 9 to obtain a segmentation image in which the contours of each particle that appeared in the analysis range are projected. Furthermore, the dimensional measurement unit 41 removes outliers and noise from the segmentation image and then performs a minimum boxing process to obtain the major axis diameter L and minor axis diameter W of each particle. In the minimum boxing process, for each particle included in the segmentation image, the smallest box that contacts the contour of the particle is determined, the major axis length of the box is taken as the major axis diameter L of the particle, and the minor axis length of the box is taken as the minor axis diameter W of the particle. For example, the contour of a particle included in a segmentation image is enclosed by two first parallel lines that are in contact with the contour, and the minimum distance between the two first parallel lines is defined as the minor axis diameter W of the particle. The contour of the particle is then enclosed by two second parallel lines that are perpendicular to the two first parallel lines and are in contact with the contour of the particle, and the minimum distance between the two second parallel lines is defined as the major axis diameter L of the particle.

[0032] The particle dimension data of the analysis range generated by the dimension measurement unit 41 includes, as shown in Figure 7, the range identification number of the analysis range, the particle number of each particle included in the analysis range, the major axis diameter L, and the minor axis diameter W.

[0033] 《Large Bulk Diameter Measurement Unit 45》 The large bulk diameter measurement unit 45 determines the large bulk diameter of the analysis range from the particle dimension data of the analysis range. The large bulk diameter measurement unit 45 has α and β, which define large bulks, stored in advance. When the numerous particles included in the analysis range are sorted in descending order of size, those included in the top β% are defined as "large bulks," and the average size of the large bulks is called the "large bulk diameter." The above "dimensions" are the long axis diameter L or the short axis diameter W, and can be selected from the long axis diameter L and the short axis diameter W depending on the conditions under which the large bulk diameter is used and the type of crushed product. β is a predetermined value between 0.00001 and 30. When the particles are sorted in descending order of size, if the percentage is below 30%, the measurement values ​​of small particles with low measurement accuracy are included, so if β is greater than 30, the measurement accuracy of the large bulk diameter may decrease.

[0034] When a large number of particles included in the analysis range are sorted in descending order of size, the measured values ​​of those in the top α% may be false positives. To improve the accuracy of large clump diameter measurement, it is preferable to exclude the measured values ​​of those in the top α% when a large number of particles included in the analysis range are sorted in descending order of size from the calculation of large clump diameter. α is a predetermined value between 0.00001 and less than 30, and smaller than β. Furthermore, the difference between β and α is preferably between 5 and 20. If the range of large clumps is expanded too much, it becomes difficult to capture the dimensional characteristics of the particles in the analysis range. The optimal values ​​for α and β differ depending on the crushing raw material and crusher. It is preferable to set the values ​​of α and β based on the results of simulations and experiments so that the large clump diameter of the crushed product 10 and the OSS of the crusher are in an approximately proportional relationship. This allows the large clump diameter of the crushed product 10 to be used as an indicator of the OSS of the crusher.

[0035] Furthermore, large chunks may be defined based on the OSS setting value of the crusher. In this case, it becomes easier to correlate the measured large chunk diameter with the OSS setting value of the crusher. For example, among the many particles included in the analysis range, those with dimensions of γ% or more of the OSS setting value of the crusher may be defined as "large chunks." The above γ is a predetermined value between 50 and 300. Preferably, the particles included in the analysis range that have dimensions of γ% or more of the OSS setting value and those included in the top β% when the many particles included in the analysis range are sorted in descending order of size generally overlap. Moreover, when large chunks are defined as described above, it is preferable to calculate the large chunk diameter by excluding particles included in the analysis range that have dimensions of ε% or more of the OSS setting value from the large chunks. ε is a predetermined value between 80 and 500, preferably between 100 and 500, and greater than γ. Preferably, the particles included in the analysis range that have dimensions of ε% or more of the OSS setting value and those included in the top α% when the multiple particles are sorted in descending order of size generally overlap. The OSS setting value, the value of γ, and the value of ε are pre-stored in the large block diameter measurement unit 45.

[0036] The large clump diameter measurement unit 45 acquires particle dimension data within the analysis range, sorts the numerous particles included in the particle dimension data in descending order of size, and identifies multiple particles as large clumps according to the predetermined rules described above (step S4). Then, the large clump diameter measurement unit 45 calculates the average value of the dimensions of the large clumps as the "large clump diameter" of the analysis range (step S5). For example, if the dimensions are set to be the major axis diameter L, α is 5, and β is 10, the numerous particles included in the particle dimension data within the analysis range are sorted in descending order of major axis diameter L, multiple particles representing the top 5% to 10% are extracted, and the average value of the major axis diameter L of these extracted particles is taken as the large clump diameter of the analysis range.

[0037] The large chunk diameter measurement unit 45 determines the large chunk diameter for each analysis range as described above, generates large chunk diameter information by linking the large chunk diameter to the range identification number of the analysis range, and stores the large chunk diameter information in the memory unit 405 (step S6). The large chunk diameter measurement unit 45 outputs the large chunk diameter information to the display unit 407 or stores it in the memory unit 405. The large chunk diameter information may also be used to determine and control the soundness of the crusher.

[0038] 《Large Bulk Diameter Monitoring Unit 46》 The large bulk diameter monitoring unit 46 acquires large bulk diameter information and monitors the changes in large bulk diameters arranged in order of the analysis range. If the large bulk diameter is observed over a relatively short period, fluctuations in the values ​​will be noticeable, but if the large bulk diameter is observed over a relatively long period, the values ​​may converge. Since the dimensions of the largest chunks contained in the crushed product respond to the OSS (Open Side Set) of the crusher, theoretically, if the OSS increases due to wear of the crusher components, the large bulk diameter will also increase.

[0039] The large chunk diameter monitoring unit 46 has pre-stored tolerance values ​​for large chunk diameters and diagnostic ranges corresponding to the OSS setting value. The diagnostic range is preferably a range that has a length in the transport direction equal to or greater than one analysis range and includes multiple analysis ranges. Preferably, the diagnostic range may be any value between 100 and 1000 m in the transport direction of the crushed product 10. The large chunk diameter monitoring unit 46 calculates the average value of the large chunk diameters of the analysis ranges included in the diagnostic range, and if this average value exceeds the tolerance value, it notifies that the OSS of the crusher is expanding due to wear or the like.

[0040] Furthermore, the large chunk diameter monitoring unit 46 has a notification threshold for the large chunk diameter stored in advance. If the dimensions of the crushed product 10 on the conveyor belt 2 exceed the notification threshold, there is a risk of the crushed product 10 accumulating on the conveyor belt 2. The notification threshold for the large chunk diameter may be a value that is sufficiently larger than the allowable value of the large chunk diameter. Since the value of the notification threshold will vary depending on the properties of the crushed product 10 and the capacity of the conveyor belt 2, it is preferable to set a suitable value obtained through simulation or experimentation. The large chunk diameter monitoring unit 46 compares the large chunk diameter calculated by the large chunk diameter measuring unit 45 with the notification threshold, and if the large chunk diameter exceeds the notification threshold, it notifies that there is a large chunk on the conveyor belt 2 that may cause the crushed product 10 to accumulate. The notification threshold may be set in multiple stages, with a first stage notification threshold and a second stage notification threshold that is larger than the first stage. In this case, the large-block diameter monitoring unit 46 first issues a first-stage notification when the large-block diameter exceeds the first-stage notification threshold, and then issues a second-stage notification when the large-block diameter exceeds the second-stage notification threshold. Here, for example, the first-stage notification may be at an alert level, and the second-stage notification may be at a warning level.

[0041] Hereinafter, a crushing system 11 according to an application example of the particle size measurement system 1 having the above configuration will be described

[0042] [Schematic Configuration of Crushing System 11] Figure 7 is a diagram showing the schematic configuration of the crushing system 11 according to an embodiment of the present disclosure. The crushing system 11 shown in Figure 7 includes a primary crusher 100, a conveyor 2, a particle size measurement system 1, and a secondary crusher 200.

[0043] The primary crusher 100 exemplified below is a gyratory crusher, and the configuration of the primary crusher 100 itself is known. However, the primary crusher 100 included in the crushing system 11 according to the present disclosure is not limited to a gyratory crusher, and may be any crusher that controls the particle size of the crushed product by the size of the crushing gap, such as a jaw crusher, for example.

[0044] Figure 8 is a schematic side cross-sectional view showing the configuration of the crusher 100 according to an embodiment of the present disclosure. The crusher 100 shown in Figure 8 includes an upper frame 111, a lower frame 113, a spider 114, a main shaft 104, a mantle 105, a concave liner 106, an eccentric sleeve 107, a power transmission mechanism 120, and the like. The main shaft 104, which performs conical motion around its upper end, is accommodated in a substantially cylindrical outer structure formed by connecting the upper frame 111 and the lower frame 113 vertically. The mantle 105 attached to the main shaft 104 and the concave liner 106 attached to the inner peripheral surface of the upper frame 111 act on the crushing raw material along with the conical motion of the main shaft 104, thereby crushing the raw material.

[0045] The upper end of the upper frame 111 is connected to the spider 114. The lower end of the upper frame 111 is connected to the upper end of the lower frame 113. The upper frame 111 is formed in a conical shape whose radial dimension decreases toward the lower side. The concave liner 106 is disposed on the inner peripheral surface of the upper frame 111.

[0046] An upper end portion of a lower frame 113 is connected to a lower end portion of an upper frame 111. The lower frame 113 is formed in a shape whose diameter increases as it extends downward. The lower end portion of the lower frame 113 is open, and crushed products can be collected from the open portion.

[0047] A main shaft 104 is housed inside the upper frame 111 and the lower frame 113. The main shaft 104 is arranged at the center in these frames 111 and 113 in a plan view and a side view, in a posture where an axis extends in the vertical direction. An upper end portion of the main shaft 104 is supported by an upper bearing 150 arranged at the center of a spider 114.

[0048] A midway portion of the main shaft 104 has a conical shape whose diameter increases as it extends downward. As approaching the lower end from the upper end of this conical portion, the gap between the outer peripheral surface of the conical portion and the inner peripheral surface of the upper frame 111 gradually narrows.

[0049] A mantle 105 is a hollow substantially conical member, and is attached to the outer peripheral surface of the conical portion of the main shaft 104. A concave bowl 106 is a plate-shaped member, and a plurality of the concave bowls are attached side by side to the inner peripheral surface of the upper frame 111. A space between the concave bowl 106 and the mantle 105 is a crushing chamber S where crushing raw material is crushed. The gap between the concave bowl 106 and the mantle 105 gradually narrows as it extends downward.

[0050] An eccentric sleeve 107 is rotationally driven by a power transmission mechanism 120 in a state where a lower end portion of the main shaft 104 is inserted into the through hole of the eccentric sleeve. The through hole of the eccentric sleeve 107 is formed in a circular shape, and is arranged eccentrically with respect to the rotational axis of the eccentric sleeve 107. A bush that enables relative rotation of the main shaft 104 with respect to the eccentric sleeve 107 is arranged between the main shaft 104 and the inner peripheral surface of the through hole of the eccentric sleeve 107.

[0051] The power transmission mechanism 120 transmits power from the drive source to the eccentric sleeve 107 to rotate the eccentric sleeve 107. The power transmission mechanism 120 includes a horizontal shaft 121, a bevel pinion 122, and a bevel gear 123, etc. The horizontal shaft 121 is supported by the lower frame 113 via a bearing 115 with its axis of rotation oriented horizontally. The bevel pinion 122 is fixed to one end of the horizontal shaft 121. The horizontal shaft 121 rotates when power is transmitted from the drive source via a V-belt and V-pulley, etc., and this also rotates the bevel pinion 122. The bevel gear 123 is fixed to the lower end of the eccentric sleeve 107. The bevel gear 123 is provided to mesh with the bevel pinion 122. As a result, the power transmitted to the horizontal shaft 121 is transmitted to the bevel gear 123, and the eccentric sleeve 107 rotates.

[0052] The rotation of the eccentric sleeve 107 causes the lower end of the main shaft 104 inserted into the eccentric sleeve 107 to pivot within a virtual horizontal plane. That is, the main shaft 104 pivots its lower end while sequentially changing the direction of its axis of rotation around the part supported by the upper bearing 150, performing a so-called pestle-like motion. As the pestle-like motion of the main shaft 104 causes the position of the mantle 105 in a plan view to fluctuate periodically, the distance between the concave 106 and the mantle 105 repeatedly increases and decreases. The rotation of the mantle 105 creates narrow and wide points in the crushing chamber S. The distance between the concave 106 and the mantle 105 at the widest point is called OSS (Open Side Set), and the distance between the concave 106 and the mantle 105 at the narrowest point is called CSS (Closed Side Set).

[0053] In the primary crusher 100 with the above configuration, the crushing material fed into the crushing chamber S from above the upper frame 111 is crushed by the action of the mantle 105 and the concave 106 to become crushed product. The size of the crushed product will be according to the setting of the OSS. A conveyor belt 2 is provided below the lower frame 113. The crushed product 10 discharged from the primary crusher 100 falls onto the conveyor belt 2 and is transported to the secondary crusher 200 by the conveyor belt 2.

[0054] The particle size measurement system 1 measures and monitors the diameter of large chunks of crushed product 10 that is transported by the conveyor belt 2.

[0055] The particle size measurement system 1 compares the measured diameter of large clumps with a pre-set notification threshold and issues a notification if the measured diameter of large clumps exceeds the notification threshold. This notification indicates the presence of large clumps that may cause accumulation of crushed product 10 on the conveyor belt 2. The notification is output in a manner that can be recognized by the operator, such as through the display of the particle size measurement system 1, a buzzer, or a warning light. Based on the notification, the operator can remove the large clumps causing the accumulation from the conveyor belt 2. The particle size measurement system 1 may also be configured to stop or slow down the conveyor belt 2 when it outputs the notification.

[0056] Furthermore, the particle size measurement system 1 monitors the change in the diameter of the largest chunks of crushed product 10 that is transported to the secondary crusher 200 by the conveyor belt 2. For example, the particle size measurement system 1 calculates the average value of the large chunk diameters within a predetermined diagnostic range, including the newly measured analysis range, and monitors the change in the average value of the large chunk diameters. The OSS gradually expands from the set value due to wear of the crusher 100's components. In response to the expansion of the OSS, the dimensions of the largest chunks contained in the crushed product 10 increase. The particle size measurement system 1 notifies when the average value of the large chunk diameters exceeds a predetermined tolerance value. This notification indicates that the OSS of the crusher 100 has expanded excessively beyond the set value due to wear, etc. The tolerance value is a value corresponding to the OSS set value and is proportional to the OSS set value. The notification is output in a manner that can be recognized by the operator, such as on the display of the particle size measurement system 1, or by a buzzer or warning light. Based on the notification, the operator can adjust the OSS during the next maintenance by changing the relative positions of the mantle 105 and concave 106 of the crusher 100.

[0057] [Summary] The particle size measurement system 1 relating to the first item of this disclosure is equipped with a calculator 400, which acquires surface shape measurement data representing the surface shape of the crushed product 10 of the crusher 100, uses image processing to determine the dimensions of multiple particles appearing on the surface of the crushed product 10 within a predetermined analysis range from the surface shape measurement data, sorts the multiple particles in descending order of size and defines those included in the top β% as large clumps, calculates the average value of the dimensions of the large clumps as the large clump diameter, and outputs the large clump diameter, where β is a predetermined value between 0.00001 and 30.

[0058] The particle size measurement system 1 with the above configuration can measure the diameter of large chunks in the crushed product 10. The measured diameter of large chunks can be used as an indicator of the actual OSS of the crusher 100. Therefore, by monitoring the change in the diameter of large chunks in the crushed product 10, it is possible to infer and detect changes in the OSS of the crusher 100.

[0059] The particle size measurement system 1 relating to the second item of this disclosure is configured such that, in the particle size measurement system 1 relating to the first item, the calculator 400 sorts a plurality of particles in descending order of size, excludes those included in the top α% from the large clumps, and determines the diameter of the large clumps, where α is a predetermined value between 0.00001 and less than 30, and smaller than β.

[0060] By sorting multiple particles within the analysis range in descending order of size, measurements of those in the top α% may be false positives. Excluding these values ​​and calculating the large particle diameter can improve the accuracy of the large particle diameter.

[0061] The particle size measurement system 1 according to the third item of this disclosure is configured such that, in the particle size measurement system 1 according to the first or second item, the calculator 400 compares the diameter of large chunks with a pre-given notification threshold and outputs a notification when the diameter of large chunks exceeds the notification threshold. Here, the notification threshold is, for example, the size of large chunks that may cause the crushed product 10 to accumulate on the conveyor belt 2.

[0062] According to the particle size measurement system 1 with the above configuration, the presence of large chunks exceeding a notification threshold in the crushed product 10 can be detected. Upon receiving the notification, the system can take action before the crushed product 10 accumulates on the conveyor belt 2, thereby ensuring the stable operation of the crushing system 11.

[0063] The particle size measurement system 1 relating to the fourth item of this disclosure is configured such that, in the particle size measurement system 1 relating to any of the first to third items, the calculator 400 calculates the average value of the large clump diameters within the analysis range included in a predetermined diagnostic range, and outputs a notification if the average value exceeds a predetermined tolerance value.

[0064] According to the particle size measurement system 1 with the above configuration, a gradual change in the OSS of the crusher 100 can be detected based on the change in the diameter of the large chunks of crushed product 10. By adjusting the OSS of the crusher 100 upon receiving notification, it is possible to avoid the average particle size of the crushed product 10 becoming excessively large, and to prevent overload in the next stage crusher 200.

[0065] The particle size measurement system 1 according to item 5 of this disclosure further comprises a surface shape measuring device 3 that measures the surface shape of the layer of crushed product 10 on the conveyor 2 and generates surface shape measurement data, in addition to the particle size measurement system 1 according to any of items 1 to 4.

[0066] According to the particle size measurement system 1 with the above configuration, the diameter of large chunks of crushed product 10 can be measured in-line.

[0067] The particle size measurement system 1 relating to item 6 of this disclosure is a particle size measurement system 1 relating to item 5, wherein the surface shape measuring device 3 has a layer thickness measuring device 5 that measures the layer thickness of the crushed product 10 on the conveyor, and is configured to measure the surface shape when the measured layer thickness exceeds a predetermined minimum layer thickness.

[0068] According to the particle size measurement system 1 with the above configuration, measurement errors due to the amount of crushed product 10 on the conveyor belt 2 can be suppressed.

[0069] The particle size measurement system 1 relating to item 7 of this disclosure includes a calculator 400, which acquires surface shape measurement data representing the surface shape of the crushed product 10 of the crusher 100, determines the dimensions of multiple particles appearing on the surface of the crushed product 10 within a predetermined analysis range from the surface shape measurement data by image processing, defines those particles having a dimension of γ% or more of the predetermined OSS setting value of the crusher as large clumps, calculates the average value of the dimensions of the large clumps as the large clump diameter, and outputs the large clump diameter, where γ is a predetermined value between 50 and 300.

[0070] The particle size measurement system 1 with the above configuration can measure the diameter of large chunks in the crushed product 10. The measured diameter of large chunks can be used as an indicator of the actual OSS of the crusher 100. Therefore, by monitoring the change in the diameter of large chunks in the crushed product 10, it is possible to infer and detect changes in the OSS of the crusher 100.

[0071] The particle dimension measurement system 1 relating to item 8 of this disclosure is configured such that the calculator 400 excludes particles from the large clump that have dimensions of ε% or more of the OSS setting value from the large clump, and ε is a predetermined value that is 80 or more and 500 or less, and is greater than γ.

[0072] Among the numerous particles included in the analysis range, measurements of those with dimensions greater than or equal to ε% of the OSS setting value may be false detections. By excluding these values ​​and calculating the large particle diameter, the accuracy of the large particle diameter can be improved.

[0073] The crushing system 11 according to item 9 of this disclosure comprises a crusher 100, a conveyor 2 for transporting the crushed product 10 from the crusher 100, and a particle size measurement system 1 according to any of items 1 to 8 for determining the diameter of the large chunks of the crushed product 10 transported by the conveyor 2.

[0074] The particle size measurement method relating to item 10 of this disclosure is a particle size measurement method performed by a calculator 400, and includes: acquiring surface shape measurement data representing the surface shape of the crushed product 10 of the crusher 100; determining the dimensions of multiple particles appearing on the surface of the crushed product 10 within a predetermined analysis range from the surface shape measurement data by image processing; sorting the multiple particles in descending order of size and defining those included in the top β% as large clumps, determining the average value of the dimensions of the large clumps as the large clump diameter; and outputting the large clump diameter, wherein β is a predetermined value of 0.00001 or more and 30 or less.

[0075] Furthermore, the particle size measurement method relating to item 11 of this disclosure is a particle size measurement method performed by a calculator 400, and includes acquiring surface shape measurement data representing the surface shape of the crushed product 10 of the crusher 100, determining the dimensions of a plurality of particles appearing on the surface of the crushed product 10 within a predetermined analysis range from the surface shape measurement data by image processing, defining those particles among the plurality of particles having a dimension of γ% or more of the OSS setting value of a predetermined crusher as large clumps, determining the average value of the dimensions of the large clumps as the large clump diameter, and outputting the large clump diameter, wherein γ is a predetermined value between 50 and 300.

[0076] According to the particle size measurement method described in items 10 and 11, the diameter of large chunks in the crushed product 10 can be measured. The measured diameter of large chunks can be used as an indicator of the OSS of the crusher 100. Therefore, by monitoring the change in the diameter of large chunks in the crushed product 10, changes in the OSS of the crusher 100 can be inferred and detected.

[0077] The embodiments described above are presented for illustrative and explanatory purposes only and are not intended to limit the disclosure to the forms disclosed herein. For example, in the detailed description above, various features of the disclosure are grouped into one embodiment for the purpose of streamlining the disclosure, but some of the features may be combined. Also, some of the features included in the disclosure may be combined into alternative embodiments, configurations, or aspects other than those discussed above.

[0078] The functions realized by the particle size measuring device 4 described herein may be implemented in a circuit or processing circuitry, including a general-purpose processor, an application-specific processor, an integrated circuit, an ASIC (Application Specific Integrated Circuit), a CPU (Central Processing Unit), conventional circuits, and / or a combination thereof, programmed to realize the described functions. A processor, including transistors and other circuits, is considered a circuit or processing circuitry. A processor may be a programmed processor that executes a program stored in memory. In this specification, circuitry, unit, and means are hardware programmed to realize or perform the described functions. Such hardware may be any hardware disclosed herein, or any hardware known to be programmed to realize or perform the described functions. If such hardware is a processor that is considered a type of circuitry, then such circuitry, means, or unit is a combination of hardware and software used to constitute such hardware and / or processor.

[0079] 1: Particle size measurement system 2: Conveyor 3: Surface shape measuring device 5: Layer thickness measuring device 10: Crushed product 11: Crushing system 100: Crusher (primary crusher) 200: Crusher (secondary crusher) 400: Calculator

Claims

1. A particle dimension measurement system comprising a calculator, wherein the calculator acquires surface shape measurement data representing the surface shape of the crushed product of a crusher, determines the dimensions of multiple particles appearing on the surface of the crushed product within a predetermined analysis range from the surface shape measurement data by image processing, sorts the multiple particles in descending order of their dimensions and defines those included in the top β% as large clumps, determines the average value of the dimensions of the large clumps as the large clump diameter, and outputs the large clump diameter, where β is a predetermined value between 0.00001 and 30.

2. The particle size measurement system according to claim 1, wherein the calculator is configured to sort the plurality of particles in descending order of size, exclude those included in the top α%, and determine the diameter of the large clump, and α is a predetermined value between 0.00001 and less than 30, and smaller than β.

3. The particle size measurement system according to claim 1, wherein the calculator is configured to compare the large particle diameter with a pre-given notification threshold and output a notification when the large particle diameter exceeds the notification threshold.

4. The particle size measurement system according to claim 1, wherein the calculator is configured to determine the average value of the large chunk diameters within the analysis range included in a predetermined diagnostic range, and to notify if the average value exceeds a predetermined tolerance value.

5. The particle size measurement system according to claim 1, further comprising a surface shape measuring device that measures the surface shape of the layer of crushed product on a conveyor and generates surface shape measurement data.

6. The particle size measurement system according to claim 5, wherein the surface shape measuring device has a layer thickness measuring device for measuring the layer thickness of the crushed product on the conveyor, and is configured to measure the surface shape when the measured layer thickness exceeds a predetermined minimum layer thickness.

7. A particle dimension measurement system comprising a calculator, wherein the calculator acquires surface shape measurement data representing the surface shape of the crushed product of a crusher, determines the dimensions of a plurality of particles appearing on the surface of the crushed product within a predetermined analysis range from the surface shape measurement data by image processing, defines those particles having dimensions of γ% or more of a predetermined OSS setting value of the crusher as large clumps, determines the average value of the dimensions of the large clumps as the large clump diameter, and outputs the large clump diameter, wherein γ is a predetermined value between 50 and 300.

8. The particle dimension measurement system according to claim 7, wherein the calculator is configured to determine the diameter of the large mass by excluding from the large mass any particles among the plurality of particles that have dimensions of ε% or more of the OSS setting value, and ε is a predetermined value of 80 to 500 and greater than γ.

9. A crushing system comprising a crusher, a conveying conveyor for transporting the crushed product of the crusher, and a particle size measurement system according to any one of claims 1 to 8 for determining the large lump diameter of the crushed product transported by the conveying conveyor.

10. A particle size measurement method performed by a computing unit, comprising: acquiring surface shape measurement data representing the surface shape of a crushed product from a crusher; determining the dimensions of a plurality of particles appearing on the surface of the crushed product within a predetermined analysis range from the surface shape measurement data by image processing; sorting the plurality of particles in descending order of their dimensions, defining those included in the top β% as large clumps, determining the average value of the dimensions of the large clumps as the large clump diameter; and outputting the large clump diameter, wherein β is a predetermined value of 0.00001 or more and 30 or less.

11. A particle size measurement method performed by a computing unit, comprising: acquiring surface shape measurement data representing the surface shape of a crushed product of a crusher; determining the dimensions of a plurality of particles appearing on the surface of the crushed product within a predetermined analysis range from the surface shape measurement data by image processing; defining those particles having dimensions of γ% or more of a predetermined OSS setting value of the crusher as large clumps, determining the average value of the dimensions of the large clumps as the large clump diameter; and outputting the large clump diameter, wherein γ is a predetermined value between 50 and 300.

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