Production apparatus and production method

Abstract

To provide a production apparatus capable of producing a granular material having a required particle size without increasing excess dust.SOLUTION: A production apparatus of the present invention includes a first production passage 10 for producing a fifth processed material having a size equal to or larger than a fourth particle diameter d2 and a sixth processed material having a size smaller than the fourth particle diameter d4 from a first processed material having a size exceeding the second particle diameter d4, and a second production passage 30A for producing the fifth processed material having a size equal to or larger than the fourth particle diameter d2 and the sixth processed material having a size smaller than the fourth particle diameter d4 from a second processed material having a size equal to or smaller than the second particle diameter d4. d3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a production apparatus and a production method suitable for producing granular materials of a required particle size. [Background technology]

[0002] For example, according to JIS A 5005, the particle size of crushed sand for concrete is 5 mm (5000 μm) or less, and the particle size range of crushed sand is standardized. For example, the amount of fine powder (dust) that passes through a 0.075 mm (75 μm) sieve in the product is standardized to be 9.0% or less. In order to keep the particle size of crushed sand within the standard range, crushed sand is sometimes produced using raw materials separated by particle size.

[0003] Patent Document 1 discloses a crushed sand plant that includes two raw material hoppers that store the raw material for crushed sand by particle size, large diameter raw material and small diameter raw material, a feeder that supplies the stored raw material from one of the two raw material hoppers to a crusher, and a crusher that crushes the supplied raw material. In the crushed sand plant of Patent Document 1, all of the raw material in the two raw material hoppers that are stored by particle size is crushed by the crusher. In other words, since small diameter raw material is also crushed by the crusher, the amount of dust contained in the product may increase. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 08-173835 Summary of the Invention [Problem to be solved by the invention]

[0005] In the crushed sand plant of Patent Document 1, small diameter raw materials are also crushed by the crusher, so depending on the particle size of the small diameter raw materials, the amount of dust contained in the product may not be within the standard.

[0006] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a production apparatus that can produce granular materials of a required particle size without increasing excess dust. [Means for solving the problem]

[0007] The production apparatus of the present invention comprises: a first production line for producing a fifth processed product having a size equal to or larger than the fourth particle diameter d4 and a sixth processed product having a size smaller than the fourth particle diameter d4 from a first processed product having a size greater than the second particle diameter d2; a second production line for producing a fifth processed product having a fourth particle size d4 or more and a sixth processed product having a size smaller than the fourth particle size d4 from a second processed product having a size equal to or smaller than the second particle size d2, The first production route is a crusher for crushing the first processed material to obtain a crushed processed material; a first classifier that classifies the crushed material to obtain a third processed material having a size of a third particle size d3 or less; and a second classifier that classifies the third processed material into a fifth processed material and a sixth processed material.

[0008] The production apparatus of the present invention comprises: The second production route merges with the first production route, It is preferable that the second processed product is classified in the first classifier and the second classifier in this order to produce a fifth processed product and a sixth processed product.

[0009] The production apparatus of the present invention comprises: The second production line joins the first production line It is preferable that the second processed product is classified by a second classifier to produce a fifth processed product and a sixth processed product.

[0010] The production apparatus of the present invention comprises: In the second production line, It is preferable that the second processed product is classified by a third classifier to produce a fifth processed product and a sixth processed product.

[0011] The production apparatus of the present invention comprises: The first classifier is The crushed material and the second processed material can be classified using the third particle size d3 as a boundary, and are divided into a third processed material having a size equal to or smaller than the third particle size d3 and a fourth processed material having a size exceeding the third particle size d3; It is preferable to provide a circulation path for supplying the fourth processed material to the crusher.

[0012] The production apparatus of the present invention comprises: The first classifier is The crushed material can be classified using the third particle size d3 as a boundary, and is divided into a third processed material having a size equal to or smaller than the third particle size d3 and a fourth processed material having a size exceeding the third particle size d3; It is preferable to provide a circulation path for supplying the fourth processed material to the crusher.

[0013] The production apparatus of the present invention comprises: The first production route is a first silo in which the first treated material is stored; a first feeder that discharges the first processed material from the first silo toward the crusher; The second production route is a second silo in which the second treated material is stored; It is preferable to further include a second feeder that discharges the second processed material from the second silo toward the first classifier.

[0014] The production apparatus of the present invention comprises: the first feeder is a vibratory feeder capable of adjusting the frequency of vibration; the second feeder is a vibratory feeder capable of adjusting the frequency of vibration; The first classifier is a vibrating sieve having a mesh that allows granular matter having a size equal to or smaller than a third particle size d3 to pass through, The second classifier is preferably an air separator that classifies by a circulating swirling air current.

[0015] The production apparatus of the present invention comprises: A particle size measuring means for measuring the particle size distribution of the fifth processed product; a supply amount adjusting unit that adjusts the supply amount of the second processed material; It is preferable to further include a control unit that controls the supply amount adjusting unit based on the particle size distribution.

[0016] The production apparatus of the present invention comprises: The third classifier is preferably an air separator that classifies by a circulating swirling air current.

[0017] The production method of the present invention comprises: Classifying the crushed processed material obtained by crushing the first processed material having a size exceeding the second particle size d2; The second processed material having a size equal to or smaller than the second particle size d2 is classified. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a production apparatus that can produce granular materials of a required particle size without increasing excess dust. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing a production device according to a first embodiment of the present invention. [Figure 2] FIG. 3 is a diagram showing a control procedure of the control device of the present invention. [Figure 3] FIG. 10 is a diagram showing the distribution volume of processed products from the production apparatus of the present invention. [Figure 4] FIG. 1 is a graph showing the standards for crushed sand and the threshold values ​​to be set according to the present invention. [Figure 5] FIG. 10 is a diagram showing the particle size history of a product produced by a production device according to an embodiment of the present invention. [Figure 6] FIG. 4 is a diagram showing a production device according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a diagram showing a production device according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The present embodiment includes at least a first embodiment, a second embodiment, and a third embodiment. In the following, the first embodiment will be described, followed by the second and third embodiments. <First embodiment: see Figs. 1 to 5> The production apparatus 1 of this embodiment produces crushed sand for concrete as granular material, as an example. This production apparatus 1 can produce granular material of a required particle size without increasing excess dust.

[0021] [Production equipment 1: See Figure 1] As shown in Figure 1, the production device 1 includes a first production path 10 that produces crushed sand CS5 as a fifth processed product having a size equal to or larger than the fourth particle size d4 and dust PW1 as a sixth processed product having a size smaller than the fourth particle size d4 from raw crushed stone RM as a first processed product having a size larger than the second particle size d2, and a second production path 30A that produces crushed sand CS5 as a fourth particle size d4 or larger and dust PW1 as a sixth processed product having a size smaller than the fourth particle size d4 from crushed sand CS1 as a second processed product having a size equal to or smaller than the second particle size d2.

[0022] Furthermore, the production apparatus 1 includes a particle size measuring means 80 that measures the particle size of the crushed sand CS5 classified by the first air separator 50, and a control device 70 that serves as a control unit that controls each device of the production apparatus 1. The arrows connecting the devices shown in Fig. 1 indicate the direction in which the processed material flows. Also, in Fig. 1, a horizontal direction H and a vertical direction V are defined.

[0023] The production device 1 includes a circulation path 62 that supplies crushed sand CS4 as the fourth processed material that does not pass through the mesh 42 of the vibrating screen 40 to the double roll crusher 20, and a fifth conveying path 65 that connects the first recovery area PA1 and the particle size measuring means 80.

[0024] Here, the raw material crushed stone RM is classified as "crushed stone" and has a particle size range of "20 to 5 mm" according to the provisions of "Table 1 - Classification by type and particle size" of JIS A 5005. Furthermore, crushed sand CS1 is classified as "crushed sand" and its particle size range is "5 mm or less" in the "Table 1 - Classification by type and particle size" of JIS A 5005, but its particle size composition falls outside the range specified in the "Table 4 - Particle size" standard of JIS A 5005. However, the particle size composition of the crushed sand CS1 stored in the second silo 31 is known, for example, by the operator operating the production apparatus 1. In this embodiment, for example, crushed sand is produced by crushing rocks excavated in a mine using a cone crusher, and the particle size distribution of the crushed sand CS1 is coarse.

[0025] A particle size composition outside the standard range means that it exceeds the range of the "mass fraction % of material passing through each sieve" specified for each dimension of the "nominal sieve dimensions (mm)" corresponding to crushed sand in "Table 4 - Particle Size" of JIS A 5005.

[0026] Specifically, in the graph of Figure 4, the upper limit UL of the standard range of "mass fraction % of material passing through each sieve" specified for each dimension of the "nominal sieve dimension mm" corresponding to crushed sand in "Table 4 - Grain size" of JIS A 5005 is plotted with square marks, and the lower limit LL of the standard range is plotted with round marks. If the grain size configuration does not fall within the range between the upper limit UL and the lower limit LL, it will be outside the standard range. In this embodiment, the mass fraction % of material passing through each sieve will be referred to as the "passing rate %."

[0027] [First production line 10: see Figure 1] As shown in Figure 1, the first production line 10 includes a double roll crusher 20 that crushes raw crushed stone RM to obtain crushed sand CS2 as a crushed processed product, a vibrating screen 40 that classifies the crushed sand CS2 to obtain crushed sand CS3 as a third processed product having a size equal to or smaller than a third particle size d3, and a first air separator 50 as a second classifier that classifies the crushed sand CS3 into crushed sand CS5 and dust PW1. The first production path 10 includes a first silo 11 for storing raw crushed stone RM having a size equal to or smaller than a first particle size d1 but larger than a second particle size d2 that is smaller than the first particle size d1, a first feeder 12 for discharging the raw crushed stone RM from the first silo 11 toward the double roll crusher 20, a first conveying path 13 for conveying the raw crushed stone RM discharged to the first feeder 12 to the double roll crusher 20, a third conveying path 14 for conveying crushed sand CS2 obtained from the double roll crusher 20 to the vibrating sieve 40, and a fourth conveying path 61 for conveying crushed sand CS3 classified by the vibrating sieve 40 to the first air separator 50. Here, the first particle size d1 is, for example, 20 mm, and the second particle size d2 is, for example, 5 mm.

[0028] The first production path 10 also includes a first collection area PA1 where crushed sand CS5 is collected, and a second collection area PA2 where dust PW1 is collected. The first production path 10 also includes a first collection path 63 that transports the crushed sand CS5 produced by the first air separator 50 to the first collection area PA1, and a second collection path 64 that transports the dust PW1 produced by the first air separator 50 to the second collection area PA2.

[0029] The raw crushed stone RM processed in the previous process is stored in the first silo 11. A first feeder 12 that discharges the raw crushed stone RM from the first silo 11 toward the double roll crusher 20 is provided below the first silo 11.

[0030] The first feeder 12 is configured as, for example, a vibrating feeder that can adjust the amount of raw crushed stone RM dispensed. The first feeder 12 is equipped with a controller (not shown) that can adjust the frequency of vibration, and adjusts the amount of raw crushed stone RM dispensed by adjusting the frequency of vibration with the controller. The first feeder 12 is controlled by a control device 70.

[0031] The first conveying path 13 connects the first feeder 12 and the double roll crusher 20 and supplies the raw crushed stone RM discharged from the first feeder 12 to the double roll crusher 20.

[0032] The third conveying path 14 connects the double roll crusher 20 and the vibrating screen 40, and supplies crushed sand CS2 produced by the double roll crusher 20 to the vibrating screen 40.

[0033] The fourth conveying path 61 connects the vibrating sieve 40 and the first air separator 50, and supplies the crushed sand CS3 classified by the vibrating sieve 40 to the first air separator 50.

[0034] [Double Roll Crusher 20: See Figure 1] The double roll crusher 20 crushes the raw crushed stone RM supplied from the first silo 11 to produce crushed sand CS2. This process corresponds to the first process of the present invention. The crushed sand CS2 is supplied to the vibrating screen 40 via the third conveying path 14. The double roll crusher 20 includes a casing 21 having a crushed stone inlet 22, a first roll 23 and a second roll 24 provided inside the casing 21, and a hydraulic cylinder 25.

[0035] The casing 21 receives the raw crushed stone RM supplied from the first silo 11 at a crushed stone inlet 22, and discharges the crushed crushed sand CS2 to the third conveying path 14. The first roll 23 and the second roll 24 are rotatable and adjacent to each other, and crush the supplied raw crushed stone RM to produce crushed sand CS2. The first roll 23 and the second roll 24 are arranged so that their rotation axes are parallel. The first roll 23 and the second roll 24 are each connected to a drive source, such as an electric motor (not shown).

[0036] In this embodiment, the diameters of the first roll 23 and the second roll 24 are, for example, approximately the same. The first roll 23 is rotated clockwise at a predetermined rotation speed by a drive source, and the second roll 24 is rotated counterclockwise at a predetermined rotation speed by a drive source. The drive source, which is an electric motor, is controlled by a control device 70. The raw material crushed stone RM supplied from the first silo 11 is crushed by passing between the first roll 23 and the second roll 24 which are rotated at a predetermined rotation speed.

[0037] It is preferable to control the respective drive sources so that the rotation speeds of the first roll 23 and the second roll 24 are approximately the same. In other words, it is preferable to control the respective drive sources so that the peripheral speeds of the first roll 23 and the second roll 24 are approximately the same. When the peripheral speeds of the first roll 23 and the second roll 24 are approximately the same, the supplied raw crushed stone RM does not easily slip on the roll surfaces, and the crushing efficiency of the double roll crusher 20 is improved.

[0038] The hydraulic cylinder 25 presses the second roll 24 in a direction that brings it closer to the first roll 23, thereby generating a crushing force that crushes the raw crushed stone RM that passes between the first roll 23 and the second roll 24.

[0039] The crushing capacity of the double roll crusher 20 can be changed by adjusting the gap between the first roll 23 and the second roll 24, adjusting the peripheral speed, and adjusting the set pressure of the oil supplied to the hydraulic cylinder 25. In addition, by adjusting the set pressure of the oil supplied to the hydraulic cylinder 25, the double roll crusher 20 can adjust the size distribution of the crushed sand CS2 crushed by the double roll crusher 20.

[0040] [Second production path 30A: see Figure 1] The second production path 30A merges with the first production path 10, and the crushed sand CS1 is classified in turn by the vibrating sieve 40 and the first air separator 50, thereby producing crushed sand CS5 and dust PW1. 1, the second production path 30A includes a second silo 31 that stores crushed sand CS1 as a second processed product having a size equal to or smaller than a second particle size d2, a second feeder 32 that serves as a supply amount adjustment unit that discharges the crushed sand CS1 from the second silo 31 toward the vibrating sieve 40, a second conveying path 33A that conveys the crushed sand CS1 discharged to the second feeder 32 to the vibrating sieve 40, and a first air separator 50 that serves as a second classifier that further classifies the crushed sand CS3 that has passed through the mesh 42 of the vibrating sieve 40. Here, the second production path 30A shares the vibrating sieve 40 and the first air separator 50 with the first production path 10.

[0041] The second production path 30A also includes a first collection area PA1 where crushed sand CS5 is collected, and a second collection area PA2 where dust PW1 is collected. The second production path 30A also includes a first collection path 63 that transports the crushed sand CS5 produced by the first air separator 50 to the first collection area PA1, and a second collection path 64 that transports the dust PW1 produced by the first air separator 50 to the second collection area PA2. Here, the second production path 30A shares the first collection area PA1, the second collection area PA2, the first collection path 63, and the second collection path 64 with the first production path 10.

[0042] The crushed sand CS1 processed in the previous process is stored in the second silo 31. A second feeder 32 that discharges the crushed sand CS1 from the second silo 31 toward the vibrating screen 40 is provided below the second silo 31.

[0043] The second feeder 32 is configured as, for example, a vibrating feeder that can adjust the amount of crushed sand CS1 dispensed. Like the first feeder, the second feeder 32 is equipped with a controller (not shown) that can adjust the frequency of vibration, and the amount of crushed sand CS1 dispensed is adjusted by adjusting the frequency of vibration with the controller. The second feeder 32 is controlled by the control device 70.

[0044] The second conveying path 33A connects the second feeder 32 and the vibrating sieve 40, and the crushed sand CS1 discharged from the second feeder 32 is supplied to the vibrating sieve 40 via the second conveying path 33A.

[0045] The fourth particle size d4 is 75 μm, and the amount of dust PW1 with a size of d4 or less, which is standardized to be contained in crushed sand for concrete products at 9.0% or less, is preferably not increased during the production of crushed sand. In other words, it is preferable to refrain from further crushing granular material that meets the particle size standard for crushed sand. This production device 1 has a second production path 30A, and by not allowing crushed sand CS1, which has a particle size of 5 mm or less and meets the crushed sand particle size standard, to be crushed by the double roll crusher 20, the generation of dust PW1 having a size of less than the fourth particle size d4 can be reduced.

[0046] Furthermore, in the particle size distribution GD of crushed sand CS5 measured by the particle size measuring means 80 described later, if the passing rate % is lower than the lower threshold value LT, the second feeder 32 is controlled to reduce the amount of material dispensed, and if the passing rate % is higher than the upper threshold value UT, the second feeder 32 is controlled to increase the amount of material dispensed.

[0047] The reason for controlling the discharge amount of the second feeder 32 to be reduced when the passing rate % is lower than the lower threshold LT is that by increasing the proportion of crushed sand CS2 with a high passing rate % produced when the raw crushed stone RM is crushed by the double roll crusher 20, and decreasing the proportion of crushed sand CS1 with a coarse particle size distribution and a low passing rate %, the passing rate % of the crushed sand CS5 that becomes the final product can be adjusted to a high particle size distribution.

[0048] In addition, when the passing rate % is higher than the upper threshold value UT, the discharge amount of the second feeder 32 is controlled to be increased because by reducing the proportion of crushed sand CS2 with a high passing rate % produced when the raw crushed stone RM is crushed by the double roll crusher 20 and increasing the proportion of crushed sand CS1 with a coarse particle size distribution and a low passing rate %, the passing rate % of the crushed sand CS5 that becomes the final product can be adjusted to a low particle size distribution.

[0049] In this embodiment, the above-described adjustments are made to supply crushed sand CS1 having a coarse particle size distribution to the vibrating sieve 40. However, when supplying crushed sand CS1 having a fine particle size distribution to the vibrating sieve 40, the opposite adjustments to those described above may be made. In other words, the passing rate % can be adjusted by adjusting the supply amount based on the particle size distribution of the crushed sand CS1.

[0050] [Vibrating sieve 40: Classification at third particle size d3 (5 mm)] The vibrating sieve 40 classifies a mixture of crushed sand CS1 discharged from the second silo 31 by the second feeder 32 and crushed sand CS2 produced by crushing raw crushed stone RM by the double roll crusher 20, using the third particle size d3 as a boundary, into crushed sand CS3 having a size equal to or smaller than the third particle size d3 and crushed sand CS4 having a size larger than the third particle size d3. This step corresponds to the second step of the present invention. The vibrating screen 40 includes a casing 41 and a mesh 42 provided inside the casing 41. The casing 41 includes an inlet 43 through which crushed sand CS1 discharged from the second silo 31 by the second feeder 32 and crushed sand CS2 produced by the double roll crusher 20 are input, a first outlet 44 through which crushed sand CS3 is discharged, and a second outlet 45 through which crushed sand CS4 is discharged. The mesh 42 is provided over the entire opening of the casing 41 when the casing 41 is viewed from above. The mesh 42 is also provided at a predetermined angle with respect to the horizontal direction H.

[0051] The mixture of crushed sand CS1 and crushed sand CS2 supplied to the upper side of the mesh 42 of the casing 41 is classified into crushed sand CS3, which passes through the mesh 42 downward in the vertical direction V, and crushed sand CS4, which remains above the mesh 42 without passing through it, as the vibrating sieve 40 vibrates.

[0052] The crushed sand CS3 that passes through the mesh 42 is discharged from the first discharge port 44 located at the bottom of the casing 41 and supplied to the first air separator 50 via the fourth conveying path 61. The crushed sand CS4 rolls on the upper side of the mesh 42, which is inclined with respect to the horizontal direction H, by vibrating the casing 41 with a vibration source (not shown), and is discharged from the second discharge port 45 located above the mesh 42. The crushed sand CS4 discharged from the second discharge port 45 is transported via the circulation path 62 to the first conveying path 13 connected to the crushed stone inlet 22 of the double roll crusher 20, and is fed into the double roll crusher 20 again.

[0053] In this embodiment, the mesh 42 has, as an example, a nominal sieve size of 5 mm as defined in JIS A 5005. Crushed sand CS3 that passes through the mesh 42 with a nominal sieve size of 5 mm satisfies the crushed sand particle size standard in JIS A 5005.

[0054] Furthermore, crushed sand CS4 that does not pass through the 5 mm mesh 42 of the sieve is larger than the standard particle size for crushed sand and is therefore returned to the double roll crusher 20 for crushing. The size of crushed sand CS3 that passes through the 5 mm sieve is equal to or smaller than the third particle size d3, while the size of crushed sand CS4 that does not pass through the 5 mm sieve exceeds the third particle size d3. However, when classification is performed on an industrial production scale, it is difficult to clearly distinguish the particle sizes of crushed sand CS3 and crushed sand CS4. Therefore, even crushed sand CS3 that is considered to be equal to or smaller than the third particle size d3 may contain a small amount of crushed sand with a particle size exceeding the third particle size d3. The same is true for crushed sand CS4 that is considered to be larger than the third particle size d3.

[0055] [First air separator 50: Classification by fourth particle size d4 (75 μm)] The first air separator 50 classifies the crushed sand CS3, which has been classified by the vibrating sieve 40 to be equal to or smaller than the third particle size d3, at a fourth particle size d4, which is smaller than the third particle size d3, to separate it into crushed sand CS5, which has a particle size equal to or larger than the fourth particle size d4, and dust PW1, which has a particle size smaller than the fourth particle size d4. This step corresponds to the third step of the present invention. The first air separator 50 performs dry classification using centrifugal force and a circulating swirling air current. As shown in Figure 1, the first air separator 50 includes a casing 51 that generates a circulating swirling air current inside, a crushed sand inlet 52 into which crushed sand CS3 is introduced, a small diameter outlet 53 from which classified dust PW1 is discharged, and a large diameter outlet 54 from which classified crushed sand CS5 is discharged.

[0056] Crushed sand CS3 classified by the vibrating sieve 40 to a third particle size d3 or smaller is supplied to the casing 51 through the crushed sand inlet 52. Fan blades (not shown) are arranged inside the casing 51, and a drive source connected to the fan blades rotates the fan blades, generating centrifugal force and a circulating swirling airflow inside the casing 51. The centrifugal force and circulating swirling airflow generated inside the casing 51 dry classify the crushed sand CS3 supplied to the casing 51, with the boundary being the fourth particle size d4.

[0057] Relatively small-diameter dust PW1 carried along with the centrifugal force and circulating swirling airflow generated inside the casing 51 is discharged from the small-diameter outlet 53. Relatively large-diameter crushed sand CS5 that is not carried along by the centrifugal force and circulating swirling airflow generated inside the casing 51 is discharged from the large-diameter outlet 54. Note that by adjusting the strength of the centrifugal force and circulating swirling airflow generated inside the casing 51, it is possible to arbitrarily change the size of the fourth particle size d4 as a predetermined particle size.

[0058] Here, as an example, the first air separator 50 adjusts the centrifugal force and the strength of the circulating swirling airflow generated inside the casing 51 so that the crushed sand CS5 discharged from the large diameter outlet 54 will have a particle size that will not pass through a metal mesh sieve with a nominal mesh size of 75 μm as specified in JIS Z 8801-1. In this case, the particle size of the dust PW1 discharged from the small diameter outlet 53 will be a particle size that will pass through a metal mesh sieve with a nominal mesh size of 75 μm.

[0059] The crushed sand CS5 discharged from the large diameter outlet 54 is collected in the first collection area PA1 via the first collection path 63 and is commercialized as crushed sand for concrete, for example. The dust PW1 discharged from the small diameter outlet 53 is collected in the second collection area PA2 via the second collection path 64.

[0060] A vibrating sieve is used instead of an air separator to classify the crushed sand CS1 and crushed sand CS2 into sizes exceeding the third particle size d3 (5 mm) and sizes equal to or smaller than the third particle size d3 (5 mm). This is because a vibrating sieve, which classifies by sieving using vibrations, is more efficient at classifying large volumes of crushed sand CS1 and crushed sand CS2 at the third particle size d3 (5 mm) boundary than an air separator, which is a so-called air-powered gravity separator.

[0061] [Particle size measuring means 80: see Figure 1] The particle size measuring means 80 samples a portion of the crushed sand CS5 collected in the first collection area PA1 and measures the particle size of the crushed sand CS5. The particle size measuring means 80 measures the particle size distribution GD of the crushed sand CS5 and adjusts the amount of crushed sand CS1 to be supplied to the vibrating sieve 40 based on the measured particle size distribution GD. This step corresponds to the fourth step of the present invention. As shown in Figure 1, the particle size measuring means 80 includes a belt conveyor 81 that transports crushed sand CS5 supplied from the first recovery area PA1 via the fifth conveying path 65, a camera 82 that captures images of the crushed sand CS5 transported by the belt conveyor 81, and a computing device 83 that calculates the particle size distribution GD of the crushed sand CS5 from the image data captured by the camera 82.

[0062] The belt conveyor 81 transports the crushed sand CS5 supplied from the first recovery area PA1 via the fifth transport path 65 by running an endless belt wound around a head pulley and a tail pulley. The camera 82 is disposed above the belt conveyor 81 and continuously captures images of the crushed sand CS5 being transported by the belt conveyor 81.

[0063] The computing device 83 calculates the particle size distribution GD of the crushed sand CS5 based on the imaging data captured by the camera 82. Specifically, it detects the edges of each particle of the crushed sand CS5 in the imaging data, recognizes the shape of the particle from the detected edges, and calculates the particle size of the particle. The particle size distribution GD of the crushed sand CS5 is calculated by calculating the distribution of particle sizes calculated from the imaging data of the crushed sand CS5 that have been continuously captured.

[0064] For example, the calculation device 83 calculates the ratios AR1 (%) to AR6 (%) of the area occupied by grains in each of the grain size ranges divided into the following grain size ranges DR1 to DR6. Below, we will explain a method for calculating the particle size distribution GD of crushed sand CS5 by calculating the area ratio AR (%) of particles in each particle size range from one image data. Note that because the camera 82 continuously captures images of the crushed sand CS5 being transported on the belt conveyor 81, the particle size distribution GD of the crushed sand CS5 may be calculated from a predetermined number of image data. DR1: DR1 ≤ 0.15 mm DR2: 0.15 mm < DR2 ≤ 0.3 mm DR3: 0.3 mm < DR3 ≤ 0.6 mm DR4: 0.6 mm < DR4 ≤ 1.2 mm DR5: 1.2 mm < DR5 ≤ 2.5 mm DR6: 2.5 mm < DR6 ≤ 5.0 mm

[0065] The arithmetic unit 83 calculates the ratio AR1 (%) of the area occupied by the particles in the particle size range of DR1 (DR1 ≤ 0.15 mm) to the total area of the crushed sand CS5 displayed on the screen of the imaging data. The calculated ratio AR1 (%) becomes the passing rate % of 0.15 mm or less. The particles in the particle size range of DR1 pass through a metal sieve with a nominal aperture of 0.15 mm defined in JIS Z 8801-1.

[0066] The arithmetic unit 83 calculates the ratio AR2 (%) of the area occupied by the particles in the particle size range of DR2 (0.15 mm < DR2 ≤ 0.3 mm) to the total area of the crushed sand CS5 displayed on the screen of the imaging data when the ratio AR1 (%) is calculated. The result of adding the ratio AR1 (%) to the ratio AR2 (%) becomes the passing rate % of 0.3 mm or less. The reason that the ratio AR1 (%) of the particles in the particle size range of DR1 is included in the passing rate % of 0.3 mm or less is that the particles in the particle size range of DR1 smaller than the particle size range of GD2 also pass through a metal sieve with a nominal aperture of 0.3 mm defined in JIS Z 8801-1. Therefore, the ratio AR1 (%) of the area of DR1 in the particle size range smaller than DR2 is added to the ratio AR2 (%) of the area of DR2, and the passing rate % of 0.3 mm or less is calculated.

[0067] In addition, when the arithmetic unit 83 calculates the ratio AR1 (%), it calculates the ratio AR3 (%) of the area occupied by the grains in the particle size range of DR3 (0.3 mm < DR3 ≤ 0.6 mm) in the total area of the crushed sand CS5 displayed on the screen of the imaging data. The result of adding the ratio AR1 (%) and the ratio AR2 (%) to the ratio AR3 (%) becomes the passing rate % of 0.6 mm or less. The reason why the ratio AR1 (%) and the ratio AR2 (%) of the grains in the particle size ranges of DR1 and DR2 are included in the passing rate % of 0.6 mm or less is that the grains in the particle size ranges of DR1 and DR2 of 0.3 mm or less, which are smaller than the particle size range of DR3, also pass through a metal sieve with a nominal mesh size of 0.6 mm defined in JIS Z 8801-1. Therefore, the ratio AR1 (%) and the ratio AR2 (%) of the areas of DR1 and DR2 in the particle size ranges smaller than DR3 are added to the ratio AR3 (%) of the area of DR3, and the passing rate % of 0.6 mm or less is calculated. That is, when calculating the passing rate % corresponding to the maximum particle size value of a certain particle size range, the ratio AR (%) of the area of the particle size range smaller than that particle size range is accumulated.

[0068] Using the ratio AR4 (%), ratio AR5 (%) and ratio AR6 (%) of the areas of the particle size ranges of DR4, DR5 and DR6, the passing rate % of 1.2 mm or less, the passing rate % of 2.5 mm or less and the passing rate % of 5.0 mm are calculated in the same way as the passing rate % of 0.6 mm or less. For example, the following respective passing rate % results are calculated as the particle size distribution GD of the crushed sand CS5. Passing rate % of 0.15 mm or less: AR1% Passing rate % of 0.3 mm or less: (AR1 + AR2)% Passing rate % of 0.6 mm or less: (AR1 + AR2 + AR3)% Passing rate % of 1.2 mm or less: (AR1 + AR2 + AR3 + AR4)% Passing rate % of 2.5 mm or less: (AR1 + AR2 + AR3 + AR4 + AR5)% Passing rate % of 5.0 mm or less: (AR1 + AR2 + AR3 + AR4 + AR5 + AR6)%

[0069] The calculated particle size distribution GD is transmitted from the arithmetic unit 83 to the control unit 70, and the control unit 70 determines whether to issue an instruction to increase or decrease the amount of crushed sand CS1 dispensed by the second feeder 32.

[0070] [Control procedure by the control device 70: see Figure 2] The control procedure of the production device 1 by the control device 70 will be described with reference to the flowchart of Fig. 2. When the control of the flowchart of Fig. 2 starts, the control device 70 has already issued an instruction to start operation of each device, and each device has already started operation. The control procedure for the production device 1 by the control device 70 includes step S1 of measuring the particle size distribution of the crushed sand CS5, step S2 of determining whether the passing rate % in the particle size distribution GD of the crushed sand CS5 is lower than a lower threshold value LT, step S3 of reducing the amount of material dispensed by the second feeder 32 if the passing rate % in the particle size distribution GD is lower than the lower threshold value LT, step S4 of determining whether the passing rate % is higher than an upper threshold value UT if the passing rate % in the particle size distribution GD of the crushed sand CS5 is equal to or greater than the lower threshold value LT, and step S5 of increasing the amount of material dispensed by the second feeder 32 if the passing rate % is higher than the upper threshold value UT.

[0071] In step S4, if the passing rate % in the particle size distribution GD of the crushed sand CS5 is equal to or less than the upper threshold value UT, that is, if the passing rate % is within the threshold range, the process proceeds to step S1.

[0072] 3A and 3B are diagrams showing the circulation amount of the processed material by the width of the arrow line, and Fig. 3A is a diagram showing the circulation amount of the processed material during normal operation. In step S4, which instructs the second feeder 32 to reduce the amount of paper dispensed if the passing rate % is lower than the lower threshold LT, the amount of paper dispensed from the second feeder 32 is reduced. In other words, as shown in FIG. 3(b), the amount of paper circulating from the second feeder 32 to the vibrating sieve 40 is reduced. In step S5, which instructs the second feeder 32 to increase the amount of paper delivered if the passing rate % is higher than the upper limit threshold UT, the amount of paper delivered from the second feeder 32 is increased. In other words, as shown in FIG. 3(c), the amount of paper delivered from the second feeder 32 to the vibrating sieve 40 is increased.

[0073] By adjusting the amount of crushed sand CS1 discharged from the second silo 31 using this control procedure, the particle size distribution GD, which varies over time, can be kept within the standard range.

[0074] [Production method using production device 1: see Figure 5] In the production method using the production device 1, crushed sand CS2 obtained by crushing raw crushed stone RM having a size exceeding the second particle size d2 is classified, and crushed sand CS1 having a size equal to or smaller than the second particle size d2 is classified. Specifically, the method for producing crushed sand for concrete using the production apparatus 1 according to this embodiment includes the following steps: Step 1, Step 2, Step 3, and Step 4. In Fig. 5, solid arrows indicate the flow of the material to be treated, and dashed arrows indicate control instructions.

[0075] <1st process> Raw crushed stone RM as a first processed product having a size exceeding the second particle size d2 is crushed by a double roll crusher 20 as a crusher to produce crushed sand CS2 as a crushed processed product. The first particle size d1 is, for example, 20 mm, and the second particle size d2 is, for example, 5 mm.

[0076] <Second process> A mixture of crushed sand CS1 as the second processed material and crushed sand CS2 as the crushed processed material is supplied to a vibrating sieve 40 as the first classifier and is classified into crushed sand CS4 as the fourth processed material having a size exceeding the third particle size d3, and crushed sand CS3 as the third processed material having a size equal to or smaller than the third particle size d3. The third particle size d3 is set to 5 mm, for example.

[0077] <3rd process> Crushed sand CS3 supplied to the first air separator 50 as a second classifier is classified into crushed sand CS5 as a fifth processed product having a size exceeding the fourth particle size d4, and dust PW1 as a sixth processed product having a size equal to or smaller than the fourth particle size d4. The fourth particle size d4 is, for example, 75 μm.

[0078] <4th process> The particle size distribution GD of the crushed sand CS5 is measured, and the amount of crushed sand CS1 to be supplied to the vibrating sieve 40 is adjusted based on the particle size distribution GD.

[0079] In the production method according to this embodiment, the crushed sand CS5 classified in the third step is commercialized as follows. Crushed sand CS5: Crushed sand for concrete (grain size range: 75μm to 5000μm)

[0080] In the production method according to this embodiment, the crushed sand CS4 of the classified product obtained in the second step is subjected to crushing in the first step together with the raw crushed stone RM. 3rd particle size d3<crushed sand CS4 (2nd process) 4th particle size d4 ≦ Crushed sand CS5 (3rd process) ≦ 3rd particle size d3

[0081] [effect] The production device 1 according to the present embodiment described above provides the following effects. [First effect] The production device 1 includes a first production path 10 that produces crushed sand CS5 having a size equal to or larger than a fourth particle size d4 and dust PW1 having a size smaller than the fourth particle size d4 from raw crushed stone RM having a size greater than the second particle size d2; The second production path 30A produces crushed sand CS1 having a size equal to or smaller than the second particle size d2 to crushed sand CS5 having a size equal to or larger than the fourth particle size d4, and dust PW1 having a size smaller than the fourth particle size d4. The production device 1 is equipped with a double roll crusher 20 on a first production path 10 that crushes raw crushed stone RM to obtain crushed sand CS2, a vibrating screen 40 that classifies the crushed sand CS2 to obtain crushed sand CS3 having a size equal to or smaller than a third particle size d3, and a first air separator 50 that classifies the crushed sand CS3 into crushed sand CS5 and dust PW1. Furthermore, the production device 1 produces crushed sand CS5 and dust PW1 by having the second production path 30A merge with the first production path 10 and classifying the crushed sand CS1 in turn using the vibrating sieve 40 and the first air separator 50. In this way, crushed sand CS1 having a size equal to or smaller than the second particle size d2 is directly subjected to classification without being crushed, and crushed sand CS2 is also subjected to classification, thereby making it possible to produce granular material of the required particle size without increasing the amount of excess dust PW1.

[0082] [Second effect] The production device 1 is equipped with a circulation path 62 that supplies crushed sand CS4, which is the fourth processed material that does not pass through the mesh 42 of the vibrating sieve 40, to the double roll crusher 20, making it possible to consume all of the raw crushed stone RM supplied to the production device 1 in the production of crushed sand CS5 without any waste.

[0083] [Third effect] The production device 1 is equipped with a vibrating sieve 40 as a first classifier that receives crushed sand CS1 from the second production path 30A and classifies it into crushed sand CS3 having a size equal to or smaller than the third particle size d3 and crushed sand CS4 having a size greater than the third particle size d3, a first air separator 50 as a second classifier that further classifies the crushed sand CS3 as the third processed product classified by the vibrating sieve 40, a particle size measuring means 80 that measures the particle size distribution GD of a portion of the crushed sand CS5 as the fifth processed product classified by the first air separator 50, and a control device 70 that controls the second feeder 32 based on the measurement results of the particle size distribution of the crushed sand CS5, thereby maintaining an appropriate particle size distribution and producing crushed sand with a stable particle size distribution.

[0084] In addition to the above, the configurations given in the above embodiments can be selected or changed as appropriate to other configurations without departing from the spirit of the present invention.

[0085] In this embodiment, the vibrating sieve 40 employs mesh 42 with a nominal size of 5 mm. However, mesh 42 with a nominal size smaller than 5 mm may be employed as long as it satisfies the crushed sand particle size standard. For example, mesh 42 with a nominal size of 2.5 mm may be employed. With such mesh 42, even if the granular matter passing rate is 100%, the crushed sand particle size standard will be satisfied.

[0086] In this embodiment, the camera 82 of the particle size measuring means 80 is disposed above the belt conveyor 81, but the present invention is not limited to this. For example, the camera 82 of the particle size measuring means 80 may be disposed above the third conveying path 14, above the fourth conveying path 61, or above the first recovery path 63 to perform particle size measurements, and the amount of crushed sand CS1 supplied to the vibrating sieve 40 may be adjusted based on the measurement results of the particle size distribution GD of the crushed sand CS2, crushed sand CS3, or crushed sand CS5. Even when these particle size distributions GD are used, an appropriate particle size distribution can be maintained, and crushed sand with a stable particle size distribution can be produced.

[0087] <Second embodiment: see FIG. 6> In the production apparatus 1 according to the first embodiment, the second conveying path 33A is connected to the vibrating sieve 40, but the present invention is not limited to this. In the production apparatus 2 according to the second embodiment, as shown in Fig. 6, the second conveying path 33B can also be connected to the fourth conveying path 61. In Fig. 6, the same elements as in Fig. 1 are assigned the same reference numerals and their description will be omitted.

[0088] In the production device 2 of this embodiment, the second production path 30B merges with the first production path 10, and crushed sand CS1 is classified in the first air separator 50, thereby producing crushed sand CS5 and dust PW1.

[0089] [Second production path 30B: see FIG. 6] 6, the second production path 30B includes a second silo 31 that stores crushed sand CS1 having a size equal to or smaller than the second particle size d2, a second feeder 32 that discharges the crushed sand CS1 from the second silo 31 toward the first air separator 50, a second conveying path 33B that conveys the crushed sand CS1 discharged to the second feeder 32 to the first air separator 50 via a fourth conveying path 61, and the first air separator 50 that further classifies the crushed sand CS3 that has passed through the mesh 42 of the vibrating sieve 40. Here, the first air separator 50 is shared with the first production path 10.

[0090] [Second conveying path 33B: see FIG. 6] The second conveying path 33B is connected to the fourth conveying path 61, and supplies the crushed sand CS1 discharged from the second feeder 32 directly to the first air separator 50 via the fourth conveying path 61. In the first embodiment, the second conveying path 33A is connected to the vibrating sieve 40, and supplies the crushed sand CS1 to the vibrating sieve 40 together with the crushed sand CS2 produced by the double roll crusher 20. The crushed sand CS1 supplied to the vibrating sieve 40 together with the crushed sand CS2 is classified by the vibrating sieve 40 at a third particle size d3, which is the particle size standard for crushed sand, as a boundary, so as to satisfy the particle size standard for crushed sand.

[0091] Here, only a portion of the crushed sand CS2 cannot pass through the mesh 42 of the vibrating sieve 40, while the crushed sand CS1, which meets the crushed sand particle size standard of the third particle size d3 or less, can pass through the mesh 42 of the vibrating sieve 40. In other words, the crushed sand CS1 does not need to be classified by the vibrating sieve 40, which classifies the crushed sand at the third particle size d3. Therefore, the crushed sand CS1 is supplied directly to the first air separator 50, where it is classified at the fourth particle size d4.

[0092] [Effects of the second embodiment] The production device 2 includes a first production path 10 that produces crushed sand CS5 having a size equal to or larger than the fourth particle size d4 and dust PW1 having a size smaller than the fourth particle size d4 from raw crushed stone RM having a size larger than the second particle size d2, and a second production path 30B that produces crushed sand CS5 having a size equal to or larger than the fourth particle size d4 and dust PW1 having a size smaller than the fourth particle size d4 from crushed sand CS1 having a size equal to or smaller than the second particle size d2. The production device 2 is equipped with a double roll crusher 20 on a first production path 10 that crushes raw crushed stone RM to obtain crushed sand CS2, a vibrating screen 40 that classifies the crushed sand CS2 to obtain crushed sand CS3 having a size equal to or smaller than a third particle size d3, and a first air separator 50 that classifies the crushed sand CS3 into crushed sand CS5 and dust PW1. Furthermore, the production device 2 produces crushed sand CS5 and dust PW1 by having the second production path 30B merge with the first production path 10 and classifying the crushed sand CS1 in the first air separator 50. In this way, crushed sand CS1 having a size equal to or smaller than the second particle size d2 is directly subjected to classification without being crushed, and crushed sand CS2 is also subjected to classification, thereby making it possible to produce granular material of the required particle size without increasing the amount of excess dust PW1.

[0093] <Third embodiment: see FIG. 7> In the production apparatus 1 according to the first embodiment, the second conveying path 33A is connected to the vibrating screen 40, and in the production apparatus 2 according to the second embodiment, the second conveying path 33B is connected to the fourth conveying path 61, but the present invention is not limited to this. In the production apparatus 3 according to the third embodiment, as shown in Fig. 7, the second conveying path 33C can also be connected to a second air separator 90 as a third classifier. In Fig. 7, the same elements as in Fig. 1 are assigned the same reference numerals and their description will be omitted.

[0094] In the production device 3 of this embodiment, crushed sand CS1 is classified by the second air separator 90 in the second production path 30C, thereby producing crushed sand CS5 and dust PW1.

[0095] [Second production path 30C: see Figure 7] 7, the second production path 30C includes a second silo 31 that stores crushed sand CS1 having a size equal to or smaller than a second particle size d2, a second feeder 32 that discharges the crushed sand CS1 from the second silo 31 toward a second air separator 90, a second conveyance path 33C that transports the crushed sand CS1 discharged to the second feeder 32 to the second air separator 90, and the second air separator 90 that classifies the crushed sand CS1 to produce crushed sand CS5 and dust PW1. The second production path 30C also includes a first collection area PA1 that collects the crushed sand CS5 and a second collection area PA2 that collects the dust PW1. The second production path 30C shares the first collection area PA1 and the second collection area PA2 with the first production path 10.

[0096] The second production path 30C also includes a third recovery path 67 that transports crushed sand CS5 produced by the second air separator 90 to the first recovery area PA1, and a fourth recovery path 68 that transports dust PW1 produced by the second air separator 90 to the second recovery area PA2. The third recovery path 67 merges with the first recovery path 63 and leads to the first recovery area PA1. The fourth recovery path 68 merges with the second recovery path 64 and leads to the second recovery area PA2.

[0097] [Second conveying path 33C: see FIG. 7] The second conveying path 33C is connected to the second air separator 90, and supplies the crushed sand CS1 discharged from the second feeder 32 directly to the second air separator 90. In the first embodiment, the second conveying path 33A is connected to the vibrating sieve 40, and supplies the crushed sand CS1 to the vibrating sieve 40 together with the crushed sand CS2 produced by the double roll crusher 20. The crushed sand CS1 supplied to the vibrating sieve 40 together with the crushed sand CS2 is classified by the vibrating sieve 40 at a third particle size d3, which is the particle size standard for crushed sand, so as to satisfy the particle size standard for crushed sand.

[0098] Here, only a portion of the crushed sand CS2 cannot pass through the mesh 42 of the vibrating sieve 40, while the crushed sand CS1, which meets the crushed sand particle size standard of the third particle size d3 or less, can pass through the mesh 42 of the vibrating sieve 40. In other words, the crushed sand CS1 does not need to be classified by the vibrating sieve 40, which classifies the crushed sand at the third particle size d3. Therefore, the crushed sand CS1 is supplied directly to the second air separator 90, where it is classified at the fourth particle size d4.

[0099] [Second air separator 90: Classification by fourth particle size d4 (75 μm)] The second air separator 90 classifies the crushed sand CS1 at a fourth particle size d4, which is smaller than the second particle size d2, and separates it into crushed sand CS5, which is equal to or larger than the fourth particle size d4, and dust PW1, which is smaller than the fourth particle size d4. Like the first air separator 50, the second air separator 90 performs dry classification using centrifugal force and a circulating swirling airflow. As shown in FIG. 7 , the second air separator 90 includes a casing 91 that generates a circulating swirling airflow inside, a crushed sand inlet 92 into which the crushed sand CS1 is introduced, a small-diameter outlet 93 from which the classified dust PW1 is discharged, and a large-diameter outlet 94 from which the classified crushed sand CS5 is discharged. A description of components that have the same functions as the first air separator 50 will be omitted, and only the destinations for collecting the crushed sand CS5 and dust PW1 will be described.

[0100] Relatively large-diameter crushed sand CS5 that is not affected by the centrifugal force and circulating swirling airflow generated inside the casing 91 is discharged from the large-diameter outlet 94. The crushed sand CS5 discharged from the large-diameter outlet 94 is collected in the first collection area PA1 via the third collection path 67 and is commercialized as crushed sand for concrete, for example. Relatively small diameter dust PW1 carried along with the centrifugal force and circulating swirling airflow generated inside the casing 91 is discharged from the small diameter outlet 93. The dust PW1 discharged from the small diameter outlet 93 is collected in the second collection area PA2 via the fourth collection path 68.

[0101] [Effects of the third embodiment] The production device 3 includes a first production path 10 that produces crushed sand CS5 having a size equal to or larger than the fourth particle size d4 and dust PW1 having a size smaller than the fourth particle size d4 from raw crushed stone RM having a size larger than the second particle size d2, and a second production path 30C that produces crushed sand CS5 having a size equal to or larger than the fourth particle size d4 and dust PW1 having a size smaller than the fourth particle size d4 from crushed sand CS1 having a size equal to or smaller than the second particle size d2. The production device 3 is equipped with a double roll crusher 20 on a first production path 10 that crushes raw crushed stone RM to obtain crushed sand CS2, a vibrating screen 40 that classifies the crushed sand CS2 to obtain crushed sand CS3 having a size equal to or smaller than a third particle size d3, and a first air separator 50 that classifies the crushed sand CS3 into crushed sand CS5 and dust PW1. Furthermore, in the production device 3, crushed sand CS1 is classified in the second air separator 90 in the second production path 30C, thereby producing crushed sand CS5 and dust PW1. In this way, crushed sand CS1 having a size equal to or smaller than the second particle size d2 is directly subjected to classification without being crushed, and crushed sand CS2 is also subjected to classification, thereby making it possible to produce granular material of the required particle size without increasing the amount of excess dust PW1. [Explanation of symbols]

[0102] 1, 2, 3 Production equipment 10 First Production Route 11 Silo No. 1 12 First Feeder 13 First conveying path 14 Third transport route 20 Double Roll Crusher 21 Casing 22 Crushed stone inlet 23 Roll 1 24 Roll 2 25 hydraulic cylinders 30A, 30B, 30C Second production line 31 Second Silo 32 Second Feeder 33A, 33B, 33C Second conveying path 40 Vibrating sieve 41 Casing 42 mesh 43 Inlet 44 1st outlet 45 2nd outlet 50 First Air Separator 51 Casing 52 Crushed sand inlet 53 Small diameter exit 54 Large diameter exit 61 4th Transport Route 62 Circulation path 63 First Recovery Route 64 Second Recovery Route 65 5th Transport Route 67 Third Recovery Route 68 4th Recovery Route 70 Control device 80 Particle size measurement means 81 Belt Conveyor 82 Camera 83 Arithmetic device 90 Second Air Separator 91 Casing 92 Crushed sand inlet 93 Small diameter exit 94 Large diameter exit AR,AR1,AR2,AR3,AR4,AR5,AR6 ratio CS1, CS2, CS3, CS4, CS5 crushed sand DR1, DR2, DR3, DR4, DR5, DR6 particle size range d1 1st particle size d2 2nd particle size d3 3rd particle size d4 4th particle size GD particle size distribution H horizontal direction LL Lower limit of specification LT Lower Threshold PA1 First Recovery Area PA2 Second Recovery Area PW1 Dust RM raw crushed stone UL standard upper limit UT upper threshold V vertical direction

Claims

1. a first production line for producing a fifth processed product having a size equal to or larger than the fourth particle diameter d4 and a sixth processed product having a size smaller than the fourth particle diameter d4 from a first processed product having a size greater than the second particle diameter d2; a second production line for producing a fifth processed product having a size equal to or larger than the fourth particle diameter d4 and a sixth processed product having a size smaller than the fourth particle diameter d4 from a second processed product having a size equal to or smaller than the second particle diameter d2, The first production path is a crusher for crushing the first processed material to obtain a crushed processed material; a first classifier that classifies the crushed material to obtain a third processed material having a size of a third particle size d3 or less; A second classifier that classifies the third processed material into the fifth processed material and the sixth processed material. Production equipment.

2. The second production path merges with the first production path, The second processed product is classified in the first classifier and the second classifier in order to produce the fifth processed product and the sixth processed product. The production device according to claim 1 .

3. The second production path merges with the first production path The second processed product is classified by the second classifier to produce the fifth processed product and the sixth processed product. The production device according to claim 1 .

4. In the second production path, The second processed product is classified by a third classifier to produce the fifth processed product and the sixth processed product. The production device according to claim 1 .

5. The first classifier is The crushed material and the second processed material are classifiable at a third particle size d3 as a boundary, and are divided into the third processed material having a size equal to or less than the third particle size d3 and the fourth processed material having a size exceeding the third particle size d3; A circulation path is provided for supplying the fourth processed material to the crusher. The production device according to claim 2 .

6. The first classifier is The crushed product can be classified using a third particle size d3 as a boundary, and is divided into a third processed product having a size equal to or smaller than the third particle size d3 and a fourth processed product having a size exceeding the third particle size d3; A circulation path is provided for supplying the fourth processed material to the crusher. The production device according to claim 3 or 4.

7. The first production path is a first silo in which the first processed material is stored; a first feeder that discharges the first processed material from the first silo toward the crusher, The second production path is a second silo in which the second processed material is stored; a second feeder that discharges the second processed material from the second silo toward the first classifier, The production device according to claim 1 or 2.

8. the first feeder is a vibrating feeder capable of adjusting a vibration frequency, the second feeder is a vibrating feeder capable of adjusting the frequency of vibration, The first classifier is a vibrating sieve having a mesh that allows granular matter having a size equal to or smaller than the third particle size d3 to pass through, The second classifier is an air separator that classifies the air by a circulating swirling airflow. The production device according to claim 7.

9. a particle size measuring means for measuring the particle size distribution of the fifth processed product; a supply amount adjusting unit that adjusts the supply amount of the second processed material; a control unit that controls the supply amount adjusting unit based on the particle size distribution, The production device according to any one of claims 2 to 4.

10. The third classifier is an air separator that classifies by a circulating swirling airflow. The production device according to claim 4.

11. classifying the crushed product obtained by crushing the first processed product having a particle size exceeding the second particle size d2; The second processed product having a size equal to or less than the second particle size d2 is classified. Production method.

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