Roller screen

Abstract

To improve capability for screening a treatment object including soil with strong viscosity.SOLUTION: A roller screen comprises: a plurality of rollers 1 disposed in parallel from one end to the other; a roller gap w set between adjacent rollers 1 and 1; a sifting out section 2 disposed below the roller gap w; an input section 3 for inputting treatment objects, disposed on the rollers 1; a collection section 4 for collecting the treatment objects, disposed at the other end in the parallel direction of the rollers 1; and a driving source 5 for rotating the rollers 1. Adopted is a method for operating the roller screen, in which the rotational speed of the rollers 1 is set as 150 or more rpm and the elevation angle relative to a horizontal direction from the other end to the one end in the parallel direction of the rollers 1 is set as 20° or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a roller screen for sorting various objects to be treated according to their size. [Background technology]

[0002] Conventionally, roller screens have been used to classify materials to be treated, such as soil and sand, crushed stone, ore, coke, and other stone materials, as well as various other lumpy and granular materials. A roller screen has multiple rotatably driven rollers arranged in parallel at a specified interval, and the materials to be treated move on the rollers in the direction in which the rollers are arranged in parallel. Materials to be treated that are smaller than the interval set between the rollers are sieved out from between the rollers, and larger materials pass over the rollers, making it possible to sieve them according to particle size (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-74056 A [Patent Document 2] JP 2002-210415 A Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, soil with a weight moisture content of 15% or more and less than 25% tends to be highly viscous and easily form lumps. For this reason, it was difficult to sift through materials containing such highly viscous soil using conventional roller screens.

[0005] In this regard, in Patent Document 1, the inclination angle of the sieve surface (screen) and the rotation direction and rotation speed of each roller are adjusted according to the properties of the clayey soil. Also, in Patent Document 2, the angle and position of the roller disks of the roller screen are adjusted according to the properties of the clayey soil. However, Patent Documents 1 and 2 do not disclose the combination of optimal operating conditions such as the inclination angle of the sieve surface (screen) and the rotation speed of each roller.

[0006] Therefore, an object of the present invention is to improve the screening ability for materials containing highly viscous soil. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention employs a roller screen comprising a plurality of rollers arranged in parallel from one end to the other end, a roller gap set between adjacent rollers, a screening section arranged below the roller gap, an input section for the material to be treated arranged on the rollers, a recovery section for the material to be treated arranged at the other end of the rollers in the parallel direction, and a drive source for rotating the rollers, and adopts an operating method for the roller screen in which the rotation speed of the rollers is 150 revolutions per minute or more and the elevation angle from the other end to one end in the parallel direction of the rollers is 20° or more with respect to the horizontal direction (configuration 1).

[0008] In the configuration 1, a configuration in which the rotation speed of the roller is set to 200 revolutions per minute or more can be adopted (configuration 2).

[0009] In the configuration 1 or 2, a configuration can be adopted in which the rotation direction of the roller is from the other end to the one end on the upper surface (configuration 3).

[0010] In any one of the configurations 1 to 3, the input section may be located at the center of the rollers in the parallel direction, or on one end side of the rollers in the parallel direction relative to the center (configuration 4).

[0011] In any one of configurations 1 to 4, a configuration in which a disk is attached to the roller can be adopted (configuration 5).

[0012] In any one of the configurations 1 to 5, the object to be treated may be a material containing soil having a weight moisture content of 15% or more and less than 25% (configuration 6).

[0013] A roller screen for use in the operating method of a roller screen according to any one of configurations 1 to 6 can be adopted, which includes a speed control section for adjusting the number of rotations of the rollers, a rotation direction control section for controlling the rotation direction of the rollers, and an angle control section for adjusting the elevation angle of the rollers from the other end to the one end in the parallel direction with respect to the horizontal direction, wherein the speed control section inverter-controls a motor which is the driving source, and the angle control section controls a hydraulic cylinder which supports a frame which supports the rollers so that the frame can be raised and lowered (configuration 7). Effect of the Invention

[0014] According to the present invention, it is possible to improve the screening ability for materials containing highly viscous soil. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a plan view showing an embodiment of the present invention; [Diagram 2] Longitudinal cross section of Fig. 1 [Diagram 3] Left side view of Figure 1 [Figure 4] Enlarged view of the main part of Figure 2 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] An embodiment of the present invention will be described with reference to the drawings. As shown in Figs. 1 to 3, the roller screen R has a plurality of rotatably driven rollers 1 arranged in parallel. A frame 6 supporting the rollers 1 is supported by an underframe 8 placed on the ground G, one end of which can be raised and lowered by a lifting device 7, and the other end of which can be rotated by a fulcrum support part 9 connected by a hinge.

[0017] The lifting device 7 in the embodiment is composed of a hydraulic cylinder. A rod of the hydraulic cylinder is connected to one end of the frame 6, and when the rod extends, one end of the frame 6 rises, and the elevation angle α of the sieve surface direction of the roller screen R (the direction connecting the axes of the parallel rollers 1 in the cross section of FIG. 2 perpendicular to the axis of the roller 1) with respect to the horizontal direction increases, and when the rod shortens, the elevation angle α decreases, constituting an inclination angle adjustment means. If the frame 8 is mounted on a traveling device, it is possible to move the device to any location. The lifting device 7 may be an air cylinder, an electric cylinder, or the like, other than a hydraulic cylinder.

[0018] The parallel rollers 1 are rotated in the same direction around their axes by the driving force supplied from each driving source 5. In the embodiment, the driving source 5 is a motor, and the rotation of the motor is transmitted to the axis of the roller 1 via a transmission means consisting of a pulley and a belt. The rotation transmitted to the axis of one roller 1 is transmitted to the axis of the other adjacent roller 1 via an auxiliary transmission means provided on the opposite side of the transmission means across the roller 1. The rotation of the other roller 1 to which the driving force has been transmitted is further transmitted to the axis of the other roller 1 via the auxiliary transmission means. As the auxiliary transmission means, for example, a sprocket attached to the axis and a chain wound between the sprockets can be used. The configurations of the transmission means and the auxiliary transmission means are not limited to those described above, and other means may be used.

[0019] A predetermined gap (interval) is set between adjacent rollers 1, 1. This gap is called roller gap w. The dimension of the roller gap w is written as w (mm). As shown in FIG. 4, the roller gap w is the shortest distance between the closest points of the outer circumferences 1a of adjacent rollers 1, 1. The roller gap w can be adjusted to any dimension. This adjustment can be performed by moving the fixing point of the shaft to the frame 6 along the parallel direction of the rollers 1. The movement of the fixing point of the shaft is performed manually, but it can also be performed automatically using a driving force based on input information, for example.

[0020] As a fixing structure between the shaft of the roller 1 and the frame 6, for example, holes may be provided intermittently at a predetermined pitch along the longitudinal direction in the frame 6 on both sides of the roller in the width direction, and both ends of the shaft of the roller 1 may be inserted into either pair of holes and the shaft may be fixed with a fastening means such as a nut, thereby adjusting the roller gap w. Alternatively, long holes may be provided along the longitudinal direction in the frame 6 on both sides of the roller in the width direction, and the roller gap w may be adjusted by sliding both ends of the shaft of the roller 1 along the length of each of the long holes and fixing the shaft at any position with a fastening means such as a nut.

[0021] An input section 3 for the material C to be treated is provided above the rollers 1. The input section 3 is a hopper located at the center of the parallel direction of the rollers 1, or closer to one end of the parallel direction than the center (the right end in Figs. 1 and 2). The material C to be treated that has dropped from the input section 3 moves on the rollers 1 along the inclination direction of the sieve surface. The material C to be treated that has a small diameter smaller than the roller gap w passes between the rollers 1 and is sieved downward, while the material C to be treated that has a large diameter larger than the roller gap w passes over the rollers 1 and reaches the other end (the left end in Figs. 1 and 2). This allows sieving according to particle size.

[0022] The location where the objects C to be treated, located below the roller gap w (below the group of rollers 1), fall is referred to as the sieving section 2, and the location where the objects C to be treated, located at the other end of the parallel direction of the rollers 1, fall is referred to as the recovery section 4. Small-diameter objects C to be treated that fall into the sieving section 2 are conveyed to the next process by a belt conveyor or the like through the first induction section 2a. Large-diameter objects C to be treated that fall into the recovery section 4 are conveyed to another next process through the second induction section 4a. The roller gap w is set to a predetermined value between 50 and 100 mm depending on the particle size of the objects C to be sieved.

[0023] The roller screen R is adapted to have its functions and operations generally controlled by a control device 30. The rotation speed of the roller 1 (the number of rotations per unit time (rpm) (min -1) is controlled by a speed control unit 31 provided in the control device 30 (see FIG. 1), and the rotation direction of the roller 1 is controlled by a rotation direction control unit 32 provided in the control device 30. The speed control unit 31 and the rotation direction control unit 32 may control each roller 1 independently (controlling the rotation speed and rotation direction of each roller 1 differently), or may control all rollers 1 in conjunction with each other (controlling the rotation speed and rotation direction of all rollers 1 the same). For example, control is made easier by inverter-controlling the motor of the drive source 5. The rotation speed can be controlled steplessly.

[0024] As shown in Fig. 2, the direction of the sieve surface of the roller screen R is set to be inclined downward toward the feeding direction of the material C to be treated (from the right side to the left side in the figure). The elevation angle α of the inclination direction with respect to the horizontal direction can be appropriately changed according to the material and particle size distribution of the material C to be treated. This elevation angle α can be adjusted by controlling the lifting device 7 with the angle control unit 33 provided in the control device 30 (see Fig. 1). The angle can be controlled steplessly.

[0025] Information required for control of the speed control unit 31, the rotation direction control unit 32, and the angle control unit 33, as well as other information required for the sieving process of the workpieces C, can be input to a setting unit 34 included in the control device 30 (see FIG. 1). Based on the information input to the setting unit 34, the control device 30 issues a command for the required operation.

[0026] Each roller 1 is also provided with a disk 10. A plurality of disks 10 are provided intermittently along the axial direction of each roller 1. The disks 10 are made of a plate-like member, and their outer edges 11 protrude radially outward beyond the outer periphery 1a of the roller 1. By providing the disks 10, the clayey soil, which is the material to be treated C, can be easily crushed and decomposed, and the screening capacity can be improved.

[0027] The angle and arrangement of the disks 10 can be freely set. In this embodiment, as shown in FIG. 2, the disks 10 are arranged in a staggered manner between adjacent rollers 1, 1, with the positions of the disks 10 shifted along the axial direction, but the arrangement of the disks 10 is not limited and may be freely set according to the properties of the clayey soil. For example, the disks 10 may be arranged in a parallel manner in which all the disks 10 are aligned in a straight line between adjacent rollers 1, 1 (the positions of the disks 10 in the axial direction of the rollers 1 are the same). In addition, as shown in FIG. 2, FIG. 3, and FIG. 4 of Patent Document 2, the surface direction of the disks 10 may be inclined with respect to the direction perpendicular to the axial direction of the rollers 1, and the inclination direction may be opposite directions for each roller 1 (the inclination direction of the disks 10 is opposite to the direction perpendicular to the axial direction of the rollers 1). Furthermore, an embodiment in which the disks 10 are not provided on some or all of the rollers 1 is also conceivable.

[0028] The number of rollers 1 arranged in parallel is appropriately set based on the distance from the supply side to the discharge side, etc. Also, the number of disks 10 provided for one roller 1 is appropriately set according to the sorting content of the workpieces C, that is, the size of the workpieces C to be dropped downward and the amount of the workpieces C to be transferred to the discharge side without dropping.

[0029] The disk 10 has three maximum diameter vertices 11a in the axial direction, which correspond to the maximum distance R1 from the axis 1b of the roller 1 in the shape of a front view along the axis of the roller 1. The maximum diameter vertices 11a are equally spaced (equally divided azimuths) in the axial direction. The disk 10 also has three minimum diameter vertices 11b in the axial direction, which correspond to the minimum distance R2 from the axis 1b of the roller 1 on the outer edge of the disk 10. The maximum diameter vertices 11a and the minimum diameter vertices 11b are alternately arranged along the axial direction, and are connected by a smooth arc. As a result, the outer edge 11 of the disk 10 has a triangular shape (so-called "rice ball shape") as a whole.

[0030] However, the shape of the disk 10 is not limited to this embodiment, and may be, for example, a shape having four or more maximum diameter apexes 11a and minimum diameter apexes 11b alternately arranged around the axis, or a shape having a circular shape (perfect circle) whose distance from the axis center is the same all around.

[0031] The operating conditions (operating method) of the roller screen R are explained below. The material C to be treated is fed from the feeding section 3, which contains highly viscous soil and stones of various particle sizes. The feeding position is slightly toward the upper part along the inclination direction of the sieve surface.

[0032] In an embodiment, (1) Roller 1 rotation speed: 150 rpm (150 revolutions / min) (2) Rotation direction of roller 1: opposite to the discharge direction of the workpiece C on its upper surface side (3) Sieve surface inclination angle: 20° or more It states that:

[0033] Combining the operating conditions (1) and (3) above is expected to prevent the clay from getting caught and to shorten the discharge time (effect 1). In addition, by adopting the above (2), the clay can be efficiently broken down and decomposed by the interaction between the sliding of the clay due to its own gravity and the rotation of roller 1 in the opposite direction to the sliding direction, and the sieving capacity can be improved (effect 2). Effect 1 due to the above (1) and (3) and effect 2 due to the above (2) can be exerted independently of each other, and if both are provided simultaneously, a synergistic effect can be exerted.

[0034] The experimental results are shown in Table 1.

[0035] Here, the target material C is "clay soil and stones." This invention is particularly effective for materials containing highly viscous soil with a weight moisture content of 15% or more and less than 25%, but in the experiment, the weight moisture content was set to 20%. Also, for the target material C, 300 kg of clay soil was mixed with 5 or 6 stones with a particle size of over 100 mm. By appropriately adjusting the angle (°) of the sieve surface with respect to the horizontal direction (hereinafter simply referred to as the angle) and the number of rotations per minute (revolutions / min) of the roller 1 (hereinafter simply referred to as the rotation speed), tests were conducted to check the change in discharge time and the occurrence of jamming.

[0036] The gradient of the sieve surface is a downward gradient along the discharge direction A of the material C (see FIG. 4). The rotation direction of the roller 1 is a direction B (see FIG. 4) opposite to the discharge direction A of the material C on its upper surface side. The roller gap w is 100 mm. The disk 10 has a triangular shape as shown in FIG. 4, and the maximum distance R1 from the axis 1b of the outer edge of the disk 10 is 200 mm.

[0037] [Table 1]

[0038] As shown in test numbers 16 to 18 in Table 1, when the angle is set to 20° and the rotation speed is set to 150 rpm, sieving of the workpiece C is possible, but the workpiece C is jammed (see the "Yes" mark in the "Whether or Not the Jamming" column for test numbers 16 and 17). On the other hand, as shown in test numbers 13 to 15, when the angle is set to 20° and the rotation speed is set to 200 rpm, jamming does not occur (see the "No" mark in the "Whether or Not the Jamming" column for test numbers 13 to 15). For this reason, in order to enable sieving of the workpiece C containing clay, it is effective to set the rotation speed to 150 rpm or more, and further, in order to prevent jamming, it is effective to set the rotation speed to 200 rpm or more. Here, although not shown in the table, it has been found that jamming is more likely to occur when the angle is set to less than 20°.

[0039] Moreover, at angles of 20°, 25°, and 30°, the discharge time is shorter when the rotation speed is set to 200 rpm than when the rotation speed is set to 150 rpm.

[0040] Although not shown in the table, it is known that if the rotation direction B of the roller 1 is set to the same direction as the discharge direction A, the discharge time becomes longer.

[0041] From the above, it can be seen that by setting the rotation speed of roller 1 to 150 rpm or more, preferably 200 rpm or more, and further setting the angle of the sieve surface to 20° or more, jamming can be prevented and the discharge time can be shortened, and further, by making the rotation direction B of roller 1 opposite to the discharge direction A, the operating efficiency can be further improved.

[0042] The object C to be treated according to the present invention may be any material containing highly viscous soil, such as construction waste soil, aggregates (crushed stone), and mixtures of clay soil with various other lumpy materials and granular materials. In particular, high effectiveness can be expected for materials containing particularly viscous soil with a weight moisture content of 15% or more and less than 25%. [Explanation of symbols]

[0043] 1. Laura 2. Sieving section 3 Input section 4. Collection Section 5. Power Source 6 Frames 7 Lifting device 8 Frame 9 Fulcrum support part 10 Disc

Claims

1. A plurality of rollers (1) arranged in parallel from one end to the other end; A roller gap (w) set between adjacent rollers (1, 1); A sieving section (2) disposed below the roller gap (w); An input section (3) for an object to be treated that is placed on the roller (1); A recovery section (4) for the object to be treated, which is disposed at the other end of the rollers (1) in the parallel direction; A drive source (5) for rotating the roller (1), The rotation speed of the roller (1) is set to 150 revolutions / minute or more, A method for operating a roller screen, in which the elevation angle from one end to the other end of the rollers (1) relative to the horizontal is 20° or more.

2. 2. The method for operating a roller screen according to claim 1, wherein the number of revolutions of the roller (1) is 200 revolutions per minute or more.

3. 2. A method for operating a roller screen according to claim 1, wherein the direction of rotation of the roller (1) is from one end to the other end on the upper surface of the roller.

4. 2. The method for operating a roller screen according to claim 1, wherein the input portion (3) is located at a center portion in the parallel direction of the rollers (1) or on one end side in the parallel direction relative to the center portion.

5. 2. A method for operating a roller screen according to claim 1, characterized in that the roller (1) is fitted with a disc (10).

6. 2. The method for operating a roller screen according to claim 1, wherein the object to be treated is a material containing soil having a moisture content by weight of 15% or more and less than 25%.

7. A roller screen used in the method for operating a roller screen according to any one of claims 1 to 6, A speed control unit (31) for adjusting the number of rotations of the roller (1); A rotation direction control unit (32) for controlling the rotation direction of the roller (1); an angle control unit (33) for adjusting an elevation angle from the other end to the one end in the parallel direction of the rollers (1) with respect to the horizontal direction; Equipped with The speed control unit (31) inverter controls the motor that is the drive source (5), The angle control unit (33) controls a hydraulic cylinder that supports a frame (6) that supports the roller (1) so that the frame can be raised and lowered.

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