Crushed sand production device and crushed sand production method

Abstract

To provide a crushed sand production apparatus capable of crushing a material to be treated and increasing the production amount of crushed sand having a desired size with respect to the charging amount of a raw material into the apparatus.SOLUTION: A crushed sand production apparatus of the present invention includes a crusher configured to crush a first processed material to obtain a second processed material, a crusher 30A configured to crush the second processed material to obtain a third processed material, a first classifier configured to classify the third processed material with a second particle diameter d2 as a boundary to obtain a fourth processed material having a size equal to or smaller than the second particle diameter d2, and a second classifier configured to classify the fourth processed material with a third particle diameter d2 smaller than the second particle diameter d3 as a boundary.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a crushed sand producing apparatus and a crushed sand producing method. [Background technology]

[0002] For example, the particle size of crushed sand for concrete is 5 mm (5000 μm) or less according to JIS A 5005, and the range of particle size for crushed sand is standardized. For example, the amount of fine powder (dust) that passes through a 0.075 mm (75 μm) sieve contained in the product is standardized to be 9.0% or less.

[0003] Double roll crushers are known as crushers for crushing materials such as raw crushed stone, which is used to make crushed sand for concrete. A double roll crusher applies compressive force to crush materials passing between two rotating rolls. The crushed materials produced by a double roll crusher may contain not only crushed sand that meets the product specifications, but also cake-like materials, which are formed by the crushed materials being compressed into clumps. Some of these cake-like materials, if broken down into dust and crushed sand, would meet the product specifications and pass through a vibrating sieve. However, these cake-like materials cannot pass through the mesh of a vibrating sieve and do not meet the product specifications. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-256126 Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 1 discloses a double roll crusher that includes two inclined rolls, one end of which has the largest diameter and the other end of which has the smallest diameter, and an inlet for the material to be treated located above the rolls on the largest diameter side. In other words, the double roll crusher of Patent Document 1 makes it easier for slippery materials to be caught between the roll surfaces, allowing the material to be crushed by applying a compressive force. However, there is no mention of the occurrence of cake-like lumps in the material to be treated due to the compressive force, nor is there any mention of crushing the material to be treated.

[0006] SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a crushed sand production device that can crush materials to be processed and increase the production amount of crushed sand of a desired size relative to the amount of raw material input to the device. [Means for solving the problem]

[0007] The crushed sand production apparatus of the present invention is a crusher for crushing the first processed material to obtain a second processed material; a crusher that crushes the second processed material to obtain a third processed material; a first classifier that classifies the third processed product at the second particle size d2 to obtain a fourth processed product having a particle size equal to or smaller than the second particle size d2; and a second classifier that classifies the fourth processed material at a third particle size d3 that is smaller than the second particle size d2.

[0008] The crushed sand production apparatus of the present invention is The crusher is preferably a double roll crusher having two rolls.

[0009] The crushed sand production apparatus of the present invention is The crusher is a casing into which the second processed material is supplied; and a striking portion that is driven to rotate inside the casing.

[0010] The crushed sand production apparatus of the present invention is The striking part is a rotation shaft that is rotated by a drive source; a rotating body rotated by a rotation shaft; It is preferable that the rotary member further comprises a plurality of hammers provided on the rotary body at intervals in the circumferential direction of the rotary shaft.

[0011] The crushed sand production apparatus of the present invention is The hammer is preferably supported so as to be swingable relative to the rotating body.

[0012] The crushed sand production apparatus of the present invention is The striking part is a plurality of movable hammers provided at intervals on a first circumference centered on the rotation axis and movable in a circumferential direction of the first circumference; It is preferable that the rotary machine further comprises a plurality of fixed hammers provided at intervals on a second circumference at a radial position different from the first circumference and centered on the rotation axis.

[0013] The crushed sand production apparatus of the present invention is It is preferable to provide a return path for supplying a fifth processed product having a particle size exceeding the second particle size d2, which is obtained by classifying the third processed product by the first classifier, to the crusher.

[0014] The crushed sand production method of the present invention comprises: crushing a second processed material obtained by crushing the first processed material; The third processed material obtained by crushing the second processed material is classified in order using the second particle size d2 as a boundary, and then using a third particle size d3 smaller than the second particle size d2 as a boundary. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a crushed sand production device that can crush materials to be treated and can increase the production amount of crushed sand of a desired size relative to the amount of raw material input to the device. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram illustrating a production device according to an embodiment of the present invention. [Figure 2]FIG. 1 is a cross-sectional view of a crusher according to an embodiment of the present invention. [Figure 3] 1A to 1C are diagrams illustrating a crushing method of a spreader according to an embodiment of the present invention. [Figure 4] 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 5] FIG. 2 is a cross-sectional view of a first modified example of a crusher according to an embodiment of the present invention. [Figure 6] 10A and 10B are diagrams illustrating a crushing method of the first modified example of the spreader according to the embodiment of the present invention. [Figure 7] 1A is a cross-sectional view of a modified example 2 of a crusher according to an embodiment of the present invention, in which (a) shows the relationship between the movable hammer and the fixed hammer, (b) is a front view of the movable hammer, and (c) is a front view of the fixed hammer. [Figure 8] 10A and 10B are diagrams illustrating a crushing method of the second modified example of the spreader according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The production apparatus 1 of this embodiment is, for example, a crushed sand production apparatus that produces crushed sand for concrete as granular material. This production apparatus 1 can crush the material to be processed, and can increase the production amount of crushed sand of a desired size relative to the amount of raw material input to the apparatus.

[0018] [Production equipment 1: See Figure 1] 1, the production apparatus 1 includes a double roll crusher 10 as a crusher that applies a compressive force to raw crushed stone RM as a first processed material to crush it, and a belt conveyor 20 that transports crushed material CM as a second processed material obtained by crushing the raw crushed stone RM with the double roll crusher 10 to a crusher 30A. The production apparatus 1 also includes the crusher 30A that crushes the crushed material CM and supplies it to a vibrating sieve 60 as a first classifier, the vibrating sieve 60 that classifies the crushed material DM as a third processed material that is crushed by the crusher 30A and supplied, and an air separator 70 as a second classifier that further classifies crushed sand CS1 as a fourth processed material that has passed through the mesh 62 of the vibrating sieve 60.

[0019] The production apparatus 1 also includes a first collection area PA1 in which crushed sand CS4 obtained by classifying crushed sand CS1 by the air separator 70 is collected, and a second collection area PA2 in which dust PW1 is collected. The production apparatus 1 also includes a return path 81 that supplies large-diameter processing material CS2 as a fifth processing material that does not pass through the mesh 62 of the vibrating sieve 60 to the double roll crusher 10, a first conveying path 82 that conveys the crushed sand CS1 classified by the vibrating sieve 60 to the air separator 70, a first collection path 83 that conveys crushed sand CS4 obtained by the air separator 70 to the first collection area PA1, and a second collection path 84 that conveys dust PW1 produced by the air separator 70 to the second collection area PA2. In Fig. 1, arrows between devices indicate the direction in which the material to be processed flows. Also, in Fig. 1, the horizontal direction H and the vertical direction V are defined as shown in the figure.

[0020] [Double Roll Crusher 10: See Figure 1] The double roll crusher 10 applies a compressive force to the raw crushed stone RM supplied from, for example, a silo (not shown), thereby crushing the raw crushed stone RM and obtaining crushed material CM. This process corresponds to the first process of the present invention. Crushing refers to crushing the raw crushed stone RM to make it smaller than the size of the raw crushed stone RM when supplied to the double roll crusher 10. The raw crushed stone RM supplied from the silo has a particle size equal to or smaller than a first particle size d1, and as an example, the first particle size d1 is 20 mm. As shown in Figure 1, the double roll crusher 10 comprises a casing 11 with a crushed stone inlet 12, the crushed stone inlet 12 through which raw crushed stone RM is introduced from a silo, a first roll 13 and a second roll 14 provided inside the casing 11, and a discharge outlet 15 through which the crushed material CM produced by crushing by the first roll 13 and the second roll 14 is discharged.

[0021] The casing 11 receives raw crushed stone RM supplied from a silo at a crushed stone inlet 12, and discharges crushed material CM obtained by crushing the raw crushed stone RM from a discharge outlet 15 onto a belt conveyor 20.

[0022] The adjacent first roll 13 and second roll 14 are arranged so that their rotation axes are parallel, and the first roll 13 and the second roll 14 are each connected to a drive source, such as an electric motor (not shown), so that each can rotate at a predetermined rotation speed.

[0023] The first roll 13 and the second roll 14 are provided with a drive source that adjusts the minimum distance between them and applies a force to move at least one of them toward the other. For example, the drive source presses the second roll 14 toward the first roll 13, thereby generating a compressive force that crushes the raw crushed stone RM passing between the first roll 13 and the second roll 14. The raw crushed stone RM supplied to the double roll crusher 10 is crushed by the compressive force from the first roll 13 and the second roll 14 when passing between the first roll 13 and the second roll 14. The distance between the first roll 13 and the second roll 14, which is adjusted by the drive source, is adjusted, for example, based on the particle size of the raw crushed stone RM supplied to the double roll crusher 10. A hydraulic cylinder, for example, is used as this drive source.

[0024] Here, the crushed material CM obtained by applying a compressive force to the raw crushed stone RM by the double roll crusher 10 is divided into crushed sand CS1 that passes through the mesh 62 of the vibrating sieve 60, and large-diameter processed material CS2 that does not pass through the mesh 62 of the vibrating sieve 60. This large-diameter processed material CS2 is divided into crushed sand CS3 and cake C. Crushed sand CS3 has a particle size that does not pass through the mesh 62 even when used alone.

[0025] Crushed sand CS1 and crushed sand CS3 are produced by crushing raw material crushed stone RM while it passes between the first roll 13 and the second roll 14. Furthermore, cake C is produced when crushed sand CS1 and crushed sand CS3, which are produced by crushing raw material crushed stone RM, are compressed into lumps by the compressive force received from the first roll 13 and the second roll 14.

[0026] The crushed sand CS1 contains crushed sand CS4 and dust PW1 that are obtained by passing through the mesh 62 of the vibrating sieve 60 and then being classified by the air separator 70. In other words, the cake C is a mass of crushed sand CS3, crushed sand CS4, and dust PW1 compressed. The cake C is supplied to the belt conveyor 20 while maintaining its shape.

[0027] [Belt conveyor 20: See Figure 1] The belt conveyor 20 is supplied with the material to be crushed CM and transports the material to be crushed CM to the crusher 30A. As shown in Fig. 1, the belt conveyor 20 includes an endless conveyor belt 21 that carries the crushed material CM, including cakes C, and transports it to the crusher 30A, and a drive pulley 22 and a driven pulley 23 around which the conveyor belt 21 is wound. A drive source, such as an electric motor (not shown), is connected to the drive pulley 22. The drive pulley 22 is continuously rotated by the electric motor from the start of operation to the stop of operation of the production apparatus 1. The rotational drive force of the electric motor is transmitted from the drive pulley 22 to cause the conveyor belt 21 to run.

[0028] When the crushed material CM is placed on the conveyor belt 21, some of the cakes C may be crushed due to the impact, but the remaining cakes C maintain the shape they had before being transferred and are transported to the crusher 30A by the conveyor belt 21.

[0029] [Crusher 30A: see Figures 1 and 2] The crusher 30A crushes the crushed material CM supplied from the belt conveyor 20 to obtain crushed material DM. This step corresponds to the second step of the present invention. Crushing refers to applying an impact force or shear force to the cakes C contained in the crushed material CM to break up the aggregated form. Even when the crushed material CM is crushed by the crusher 30A, a small amount of the cakes C still retain their shape in the crushed material DM. 1, the crusher 30A includes a casing 31A into which the material to be crushed CM is supplied and which crushes the material to be crushed CM inside the casing 31A, and an impact unit 40A which is driven to rotate inside the casing 31A and applies an impact force or shear force to the material to be crushed CM. The method of crushing the material to be crushed CM by the crusher 30A will be described later.

[0030] 2, the casing 31A is provided with a hopper 32 that stores the shredded material CM to be fed in, and a discharge port 38A that discharges the shredded material DM obtained by shredding the shredded material CM. The hopper 32 is provided with an inlet 37A through which the shredded material CM is fed in. The casing 31A is also provided with a screw feeder 33 that connects the hopper 32 and the crushing area 35A, and the crushing area 35A where the material to be crushed CM is crushed by the impact unit 40A. A screw shaft 33A is installed inside the screw feeder 33 to send the input material to be crushed CM to the crushing area 35A.

[0031] [Striking section 40A: see Figure 2] The striking section 40A includes a rotary shaft 41A rotated by a drive source (not shown), and a plurality of hammers 42A provided at equal intervals around the circumference of the rotary shaft 41A. The rotary shaft 41A rotates clockwise on the page of FIG. 2, as indicated by arrow R1. A rotary disk 46A is provided radially outward of the rotary shaft 41A as a rotating body rotated by the rotary shaft 41A. The rotary disk 46A is fixed to the rotary shaft 41A by, for example, a key or a friction-type fastening joint, limiting rotation around the axis of the rotary shaft 41A.

[0032] The hammer 42A is composed of a head 43A that impacts the material to be crushed CM to crush the cakes C, an arm 44A on the tip side of which the head 43A is provided, and a pin 45A that connects the base end of the arm 44A to a rotating disk 46A that is rotated by a rotating shaft 41A and supports the arm 44A so that it can swing. The shape of the head 43A, which is triangular when viewed from the front of the hammer 42A, may be, for example, circular or another polygonal shape, and a head of a shape suitable for crushing the cakes C is used. The hammer 42A can swing around the pin 45A, as shown by arrow R2.

[0033] For example, even if the material to be crushed CM becomes stuck between the head 43A and the inner wall 31AA of the casing 31A while the rotating shaft 41A is rotating, the hammer 42A can swing in the direction opposite to the direction of rotation of the rotating shaft 41A, thereby immediately releasing the jamming. This swinging action of the hammer 42A can reduce the shear force applied to the material to be crushed CM, preventing further crushing of the material to be crushed CM.

[0034] [Vibrating sieve 60: See Figure 1] The vibrating sieve 60 classifies the crushed material DM supplied from the crusher 30A at the second particle size d2 as a boundary, and separates it into crushed sand CS1 having a size equal to or smaller than the second particle size d2 and large-diameter material CS2 having a size exceeding the second particle size d2. This step corresponds to the third step of the present invention.

[0035] As shown in Fig. 1, the vibrating sieve 60 includes a casing 61 and a mesh 62 provided inside the casing 61. The casing 61 includes an inlet 63 through which the crushed material DM supplied from the crusher 30A is introduced, a first outlet 64 through which crushed sand CS1 is discharged, and a second outlet 65 through which large-diameter material CS2 is discharged. The mesh 62 is provided over the entire opening of the casing 61 when the casing 61 is viewed from above. In this embodiment, the mesh 62 is provided at an angle relative to the horizontal direction H, but this is not limiting and the mesh 62 may be provided in the horizontal direction H. The vibrating sieve 60 is vibrated by a vibration source (not shown).

[0036] In this embodiment, the mesh 62 has, as an example, a nominal sieve size of 5 mm as defined in JIS A 5005. Crushed sand CS1 that passes through the mesh 62 with a nominal sieve size of 5 mm satisfies the crushed sand particle size standard in JIS A 5005. The crushed material DM supplied from the crusher 30A is supplied to the upper side of the mesh 62, and as the vibrating sieve 60 vibrates, it is classified into crushed sand CS1 that passes through the mesh 62 downward in the vertical direction V, and large-diameter processed material CS2 that remains on the upper side without passing through the mesh 62.

[0037] The crushed sand CS1 that passes through the mesh 62 is discharged from a first discharge port 64 disposed in the lower part of the casing 61, and is supplied to the air separator 70 via a first conveying path . The large-diameter material CS2 to be treated rolls on the upper side of the mesh 62, which is inclined with respect to the horizontal direction H, by vibrating the casing 61 with a vibration source (not shown), and is discharged from the second discharge outlet 65, which is located above the mesh 62. The large-diameter material CS2 discharged from the second discharge outlet 65 is transported via a return path 81 connected to the crushed stone inlet 12 of the double roll crusher 10, and is fed into the double roll crusher 10 again.

[0038] Furthermore, the large-diameter material CS2 that does not pass through the 5 mm mesh 62 of the sieve is larger than the standard particle size for crushed sand and is therefore returned to the double roll crusher 10 for crushing. The size of the crushed sand CS1 that passes through the 5 mm sieve is equal to or smaller than the second particle size d2, while the size of the crushed sand CS3 and cake C contained in the large-diameter material CS2 that does not pass through the 5 mm sieve exceeds the second particle size d2. However, when classification is performed on an industrial production scale, it is difficult to clearly distinguish the particle sizes of the crushed sand CS1 and the large-diameter material CS2. Therefore, even crushed sand CS1 that is equal to or smaller than the second particle size d2 may contain a small amount of crushed sand with a particle size exceeding the second particle size d2. The same is true for the large-diameter material CS2 that is larger than the second particle size d2.

[0039] [Air separator 70: Classification by third particle size d3 (75 μm)] The air separator 70 classifies the crushed sand CS1, which has been classified by the vibrating sieve 60 into particles of the second particle size d2 or smaller, at a third particle size d3, which is smaller than the second particle size d2, and separates the crushed sand CS4, which has a particle size of the third particle size d3 or larger, from dust PW1, which has a particle size smaller than the third particle size d3. This step corresponds to the fourth step of the present invention. The air separator 70 performs dry classification using centrifugal force and a circulating swirling air current. As shown in Figure 1, the air separator 70 includes a casing 71 that generates a circulating swirling air current inside, a crushed sand inlet 72 into which crushed sand CS1 is introduced, a small diameter outlet 73 from which classified dust PW1 is discharged, and a large diameter outlet 74 from which classified crushed sand CS4 is discharged.

[0040] Crushed sand CS1 classified by the vibrating sieve 60 to a second particle size d2 or smaller is supplied to the casing 71 through a crushed sand inlet 72. Fan blades (not shown) are arranged inside the casing 71, and a drive source connected to the fan blades rotates the fan blades, generating centrifugal force and a circulating swirling airflow inside the casing 71. The centrifugal force and circulating swirling airflow generated inside the casing 71 dry classify the crushed sand CS1 supplied to the casing 71, with the third particle size d3 as the boundary.

[0041] Relatively small diameter dust PW1 carried along with the centrifugal force and circulating swirling airflow generated inside the casing 71 is discharged from the small diameter outlet 73. Relatively large diameter crushed sand CS4 that is not carried along by the centrifugal force and circulating swirling airflow generated inside the casing 71 is discharged from the large diameter outlet 74. Note that by adjusting the strength of the centrifugal force and circulating swirling airflow generated inside the casing 71, it is possible to arbitrarily change the size of the third particle size d3 as a predetermined particle size.

[0042] Here, as an example, the air separator 70 adjusts the centrifugal force and the strength of the circulating swirling airflow generated inside the casing 71 so that the crushed sand CS4 discharged from the large diameter outlet 74 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 73 will be such that it will pass through a metal mesh sieve with a nominal mesh size of 75 μm.

[0043] The crushed sand CS4 discharged from the large diameter outlet 74 is collected in the first collection area PA1 via the first collection path 83 and is commercialized as crushed sand for concrete, for example. The dust PW1 discharged from the small diameter outlet 73 is collected in the second collection area PA2 via the second collection path 84.

[0044] A vibrating sieve is used instead of an air separator to classify the crushed sand CS1 and the large-diameter material CS2 into particles exceeding the second particle size d2 (5 mm) and particles equal to or smaller than the second particle size d2 (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 large-diameter material CS2 at the boundary of the second particle size d2 (5 mm), than an air separator, which is a so-called air-powered gravity separator.

[0045] [Method of producing crushed sand using production equipment 1: see Figure 3] The crushed sand production method using the production device 1 involves crushing the crushed material CM obtained by crushing the raw crushed stone RM, and then classifying the crushed material DM obtained by crushing the crushed material CM, in order, using the second particle size d2 as a boundary, and then classifying it using a third particle size d3 smaller than the second particle size d2 as a boundary. 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. The arrows in Figure 3 indicate the flow of the processed material.

[0046] <1st process> Crushed material CM is obtained by crushing raw crushed stone RM having a size equal to or smaller than a first particle size d1 using a double roll crusher 10. The first particle size d1 is set to 20 mm, for example.

[0047] <Second process> The crushed material CM is crushed by a crusher 30A to obtain a crushed material DM.

[0048] <3rd process> The crushed material DM supplied to the vibrating sieve 60 is classified into crushed sand CS1 having a size equal to or smaller than the second particle size d2 and large-diameter material CS2 having a size greater than the second particle size d2. The second particle size d2 is, for example, 5 mm.

[0049] <4th process> The crushed sand CS1 supplied to the air separator 70 is classified into crushed sand CS4 having a size equal to or larger than the third particle size d3 and dust PW1 having a size smaller than the third particle size d3. The third particle size d3 is set to 75 μm, for example.

[0050] In the production method using the production apparatus 1 according to this embodiment, the crushed sand CS4 classified in the fourth step is commercialized as follows. Crushed sand CS4: Crushed sand for concrete (particle size range 75μm to 5000μm)

[0051] In the production method using the production apparatus 1 according to this embodiment, the large-diameter processed material CS2 of the classified product obtained in the third step is subjected to crushing in the first step together with the raw crushed stone RM. Second particle size d2<Large diameter processed material CS2 (third process) 3rd particle size d3 ≦ Crushed sand CS4 (4th step) ≦ 2nd particle size d2

[0052] [Method of crushing the crushed material CM using the crusher 30A: see Figure 4] A crushing method for crushing the cakes C included in the crushed material CM by the crusher 30A will be described with reference to FIG.

[0053] As shown in FIG. 4(a), the material to be crushed CM fed through the inlet 37A is stored in the hopper 32. The stored material to be crushed CM includes crushed sand CS1 and large-diameter material to be crushed CS2. The stored material to be crushed CM is sent toward the crushing area 35A by the rotation of the screw shaft 33A of the screw feeder 33 provided at the bottom of the hopper 32. When the cakes C move from the hopper 32 to the screw feeder 33, they are broken up by the blades of the screw shaft 33A. At this time, the cakes C become smaller than when they were fed through the inlet 37A, and are transported by the screw feeder 33.

[0054] As shown in Figure 4(b), the cakes C that reach the crushing area 35A are crushed by the impact force of the hammers 42A of the rotating impact unit 40A or by the shear force generated between the casing 31A and the head 43A. As the hammers 42A continue to rotate in the direction of arrow R1, the material CM to be crushed passes above the vertical direction V of the rotating shaft 41A while being crushed by the hammers 42A. Crushed sand CS1 and crushed sand CS3 obtained by crushing the cakes C contained in the material CM to be crushed also pass above the vertical direction V of the rotating shaft 41A.

[0055] 4(c), crushed sand CS1 and large-diameter material CS2 obtained when the crushed material CM is crushed by the impacting unit 40A pass above the vertical direction V of the rotating shaft 41A, move in the direction of rotation of the rotating shaft 41A, and are discharged from the discharge port 38A of the casing 31A. The discharged crushed material DM is supplied to a vibrating sieve 60 provided below the crusher 30A.

[0056] [effect] The production device 1 according to the present embodiment described above provides the following effects. [First effect] The production apparatus 1 includes a double roll crusher 10 that crushes raw crushed stone RM to obtain crushed material CM, a crusher 30A that crushes the crushed material CM to obtain crushed material DM, and a vibrating sieve 60 that classifies the material at a second particle size d2. The production apparatus 1 can crush the crushed material CM using the crusher 30A, and can increase the production amount of crushed sand of a desired size relative to the amount of raw crushed stone RM input to the production apparatus 1 as the raw material.

[0057] [Second effect] The production device 1 is equipped with a return path 81 that supplies large-diameter processing material CS2 that does not pass through the mesh 62 of the vibrating screen 60 to the double roll crusher 10, making it possible to consume all of the raw crushed stone RM supplied to the production device 1 in the production of crushed sand CS4 without any waste.

[0058] 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.

[0059] In addition to the crusher 30A, crusher 30B, in which the connection between the hammer and the rotating shaft is fixedly supported, or crusher 30C, in which a hammer fixed to a casing and a hammer that rotates together with the rotating shaft, may also be used to crush the crushed material CM.

[0060] [Crusher 30B: see Figure 5] The crusher 30B crushes the crushed material CM supplied from the belt conveyor 20, and supplies the crushed material DM to the vibrating sieve 60, similar to the crusher 30A. As shown in Figure 5, the crusher 30B comprises a casing 31B into which the material to be crushed CM is supplied and which crushes the material to be crushed CM inside the casing 31B, and an impact unit 40B which is rotated inside the casing 31B and applies an impact force or shear force to the material to be crushed CM.

[0061] 5, the casing 31B is provided with an inlet 37B through which the material to be crushed CM is fed, and an outlet 38B through which the crushed material DM obtained by crushing the material to be crushed CM is discharged. The casing 31B also has a crushing region 35B in which the material to be crushed CM is crushed by an impact section 40B.

[0062] Furthermore, a gap adjustment unit 36 ​​is provided on the side of the casing 31B opposite the open side of the inlet 37B in the horizontal direction H. The gap adjustment unit 36 ​​adjusts the gap between the striking unit 40B and the hammers 42B, thereby adjusting the size of the crushed material DM discharged from the crusher 30B. The gap adjustment unit 36 ​​includes a liner 36A whose gap LB between the liner 36A and the trajectory 42BA of the hammers 42B is adjustable, and a pin 36B that swingably supports the liner 36A near the upper end in the vertical direction V. The gap adjustment unit 36 ​​also includes a rod 36C attached near the lower end of the liner 36A in the vertical direction V, and an adjustment unit 36D that can adjust the gap LB between the liner 36A and the hammers 42B by changing the position of the rod 36C in the horizontal direction H.

[0063] [Striking part 40B: see Figure 5] The striking section 40B includes a rotary shaft 41B rotated by a drive source (not shown) and a plurality of hammers 42B arranged at equal intervals around the circumference of the rotary shaft 41B. The rotary shaft 41B rotates clockwise on the page of FIG. 5, as indicated by arrow R2. A rotary disk 46B is provided radially outward of the rotary shaft 41B as a rotating body rotated by the rotary shaft 41B. The rotary disk 46B is fixed to the rotary shaft 41B by, for example, a key or a friction-type fastening joint, limiting its rotation around the axis of the rotary shaft 41B. The hammers 42B extend from the inner to the outer radial direction of the rotary shaft 41B.

[0064] The base of the hammer 42B is fixedly supported on a rotating disc 46B that is rotated by the rotating shaft 41B. As the rotating shaft 41B rotates, the fixedly supported hammer 42B also rotates in the direction of arrow R2. The trajectory 42BA of the hammer 42B as it rotates together with the rotating shaft 41B is shown by a two-dot chain line. When viewed from the front, the hammer 42B has a generally rectangular shape. The shape of the hammer 42B may be an arc shape or another polygonal shape, and a shape suitable for crushing the cakes C is used.

[0065] [Method of crushing the crushed material CM using the crusher 30B: see FIG. 6] A crushing method for crushing the cakes C included in the crushed material CM by the crusher 30B will be described with reference to FIG.

[0066] As shown in FIG. 6(a), the material to be crushed CM fed through the feed opening 37B falls until it reaches the rotating striking unit 40B. Cakes C of the material to be crushed CM that reach the hammers 42B of the striking unit 40B are subjected to an impact force when they collide with the rotating hammers 42B. The cakes C are also bounced by the hammers 42B to the inner wall 31BA of the casing 31B, where they are subjected to an impact force when they collide with the inner wall 31BA. These impact forces cause the cakes C to break down.

[0067] As shown in Figure 6(b), crushed sand CS1 and crushed sand CS3 obtained by crushing cake C move in the direction of rotation of the rotating shaft 41B while being bounced off by hammer 42B. Crushed sand CS1 and crushed sand CS3 that have moved in the direction of rotation of the rotating shaft 41B pass through the gap LB between the gap adjustment part 36 and liner 36A and are discharged from the discharge port 38B of the casing 31B. The discharged crushed material DM is supplied to a vibrating sieve 60 provided below the crusher 30B.

[0068] [Crusher 30C: see Figure 7] The crusher 30C crushes the crushed material CM supplied from the belt conveyor 20, and supplies the crushed material DM to the vibrating sieve 60, similar to the crushers 30A and 30B. As shown in Figure 7(a), the crusher 30C comprises a casing 31C into which the crushed material CM is supplied and which crushes the crushed material CM inside, and an impact unit 40C which is rotated inside the casing 31C and applies an impact force or shear force to the crushed material CM.

[0069] 7(a), the casing 31C is provided with an inlet 37C through which the material to be crushed CM is fed, and an outlet 38C through which the crushed material DM obtained by crushing the material to be crushed CM is discharged. The casing 31C also has a crushing region 35C in which the material to be crushed CM is crushed by an impacting section 40C.

[0070] [Striking part 40C: see Figure 7] 7(b) and 7(c), the striking section 40C includes a plurality of movable hammers 42C provided at intervals on a first circumference C1 centered on a rotation axis 41D, which is the rotation center of the rotating disk 41C, and moving in the circumferential direction of the first circumference C1, and a plurality of fixed hammers 46C provided at intervals on a second circumference C2 centered on the rotation axis 41D and at a different radial position from the first circumference C1. The striking section 40C further includes a plurality of movable hammers 42C provided at intervals on a third circumference C3 centered on the rotation axis 41D and at a different radial position from the first circumference C1 and the second circumference C2, and moving in the circumferential direction of the third circumference C3, and a plurality of fixed hammers 46C provided at intervals on a fourth circumference C4 centered on the rotation axis 41D and at a different radial position from the first circumference C1, the second circumference C2, and the third circumference C3.

[0071] In this embodiment, the rotary disk 41C is provided on the rear side surface 31CB of the casing 31C. The movable hammer 42C is a cylindrical pin extending from the rotary disk 41C toward the front side surface 31CC opposite the rear side surface 31CB. The fixed hammer 46C is a cylindrical pin extending from the front side surface 31CC toward the rear side surface 31CB of the casing 31C.

[0072] The rows of movable hammers 42C and the rows of fixed hammers 46C are arranged alternately from the inside to the outside in the radial direction of the rotating disc 41C. By arranging the rows of movable hammers 42C and the rows of fixed hammers 46C alternately, a shear force can be applied to the material to be crushed CM that has gotten between the moving movable hammer 42C and the fixed hammer 46C that is fixed in position.

[0073] The movable hammer 42C rotates in the direction of arrow R3 together with the rotating disc 41C, which is rotated by the drive source. The shape of the movable hammer 42C is circular when viewed from the front, but it may be a polygonal shape such as a triangle or a square, and any shape suitable for crushing the cakes C is used.

[0074] [Method of crushing the crushed material CM using the crusher 30C: see Figure 8] A crushing method for crushing the cakes C included in the crushed material CM by the crusher 30C will be described with reference to FIG.

[0075] As shown in FIG. 8(a), the material CM to be crushed is fed through the feed opening 37C and falls until it reaches the rotating impact unit 40C. When the cakes C of the material CM to be crushed reach the movable hammer 42C of the impact unit 40C, they are subjected to an impact force when they collide with the rotating movable hammer 42C. The cakes C are also bounced by the movable hammer 42C towards the inner wall 31CA of the casing 31C, and are subjected to the impact force when they collide with the inner wall 31CA. These impact forces cause the cakes C to break down. Furthermore, cakes C that have fallen between the rotating movable hammer 42C and the fixed hammer 46C are crushed by the shearing force applied from the movable hammer 42C and the fixed hammer 46C.

[0076] 8(b), crushed sand CS1 and crushed sand CS3 obtained by crushing cake C are bounced off by movable hammer 42C, move in the direction of arrow R3, and are discharged from discharge port 38C of casing 31C. The discharged crushed material DM is supplied to a vibrating sieve 60 provided below crusher 30C. [Explanation of symbols]

[0077] 1. Production equipment 10 Double Roll Crusher 11 Casing 12 Crushed stone inlet 13 Roll 1 14 Roll 2 15 Outlet 20 Conveyor Belt 21 Conveyor Belt 22 Drive pulley 23 Driven pulley 30A,30B,30C crusher 31A, 31B, 31C Casing 31AA,31BA,31CA Inner wall 31CB rear side 31CC front side 32 Hopper 33 Screw feeder 33A screw shaft 35A,35B,35C Crushing area 36 Spacing adjustment section 36A Liner 36B pin 36C Rod 36D adjustment section 37A,37B,37C Inlet 38A, 38B, 38C outlet 40A, 40B, 40C striking section 41A, 41B Rotating shaft 41C Rotating disc 41D Rotation axis 42A, 42B Hammer 42BA locus 42C Movable Hammer 43A Head 44A Arm 45A pin 46C Fixed Hammer 60 vibrating sieve 61 Casing 62 mesh 63 Inlet 64 1st outlet 65 2nd outlet 70 Air Separator 71 Casing 72 Crushed sand inlet 73 Small diameter exit 74 Large diameter exit 81 Return Route 82 First conveying route 83 First Recovery Route 84 Second Recovery Route C Cake CM crushed material C1 First circumference C2 Second Circumference C3 Third Circumference C4 4th Circumference CS1 crushed sand CS2 Large diameter processing object CS3 crushed sand CS4 crushed sand d1 1st particle size d2 2nd particle size d3 3rd particle size DM crushed material H horizontal direction LB spacing PA1 First Recovery Area PA2 Second Recovery Area PW1 Dust R1 Arrow R2 Arrow R3 Arrow RM raw crushed stone V vertical direction

Claims

1. a crusher for crushing the first processed material to obtain a second processed material; a crusher that crushes the second processed material to obtain a third processed material; a first classifier that classifies the third processed product at a second particle size d2 to obtain a fourth processed product having a particle size equal to or smaller than the second particle size d2; A second classifier that classifies the fourth processed product at a third particle size d3 that is smaller than the second particle size d2. Crushed sand production equipment.

2. The crusher is a double roll crusher having two rolls. The crushed sand producing apparatus according to claim 1.

3. The crusher is a casing into which the second processed material is supplied; a striking section that is rotationally driven inside the casing, The crushed sand producing apparatus according to claim 1 or 2.

4. The hitting part is a rotation shaft that is rotated by a drive source; a rotating body that is rotated by the rotation shaft; a plurality of hammers provided on the rotating body at intervals in the circumferential direction of the rotating shaft, The crushed sand producing apparatus according to claim 3.

5. The hammer is supported so as to be swingable relative to the rotating body.

5. The crushed sand producing apparatus according to claim 4.

6. The hitting part is a plurality of movable hammers provided at intervals on a first circumference centered on the rotation axis and movable in a circumferential direction of the first circumference; a plurality of fixed hammers provided at intervals on a second circumference at a radial position different from the first circumference, the second circumference being centered on the rotation axis, The crushed sand producing apparatus according to claim 3.

7. A return path is provided for supplying a fifth processed product having a size exceeding the second particle size d2 obtained by classifying the third processed product by the first classifier to the crusher. The crushed sand producing apparatus according to claim 1 or 2.

8. crushing a second processed material obtained by crushing the first processed material; A third processed product obtained by crushing the second processed product is classified, in order, at a second particle size d2 as a boundary, and at a third particle size d3 smaller than the second particle size d2 as a boundary. Crushed sand production method.

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