JP7380371B2 - belt feeder - Google Patents

Description

The present invention relates to a belt feeder that performs quantitative cutting of powder or granular material.

BACKGROUND ART Belt feeders are widely used, which include a powder feeding device and a belt conveyor for conveying the powder and granule, and cut out a fixed amount of the powder and granule (see Patent Documents 1 and 2).

Here, a plurality of return rollers are normally installed below the return path of the belt conveyor that constitutes the belt feeder in order to prevent the belt from flexing downward (p. 5 of Patent Document 1, (See Figure 3).

On the other hand, the belt running speed of a belt feeder that cuts out a fixed amount of powder or granules is significantly lower than the conveyance speed of a general belt conveyor.

Due to the above-mentioned structure and basic operation mode, in many belt feeders, even after cutting out a fixed amount, a part of the input powder is not discharged from the discharge port that performs the fixed cutting, and the surface of the belt is remains attached to the surface and reaches the return route as "residual powder". Most of these "residual particles" are returned without peeling or falling even when the adhering surface is facing down on the return route, and come into contact with the return roller installed on the return route. As a result, it peels off from the belt surface and falls to the area below the return roller. In this way, in many belt feeders, a pile of "residual powder" accumulates on the floor below the return roller on the return path, and cleaning is required to periodically collect it. The work had become mandatory. In addition, in this specification, among the "powder and granular materials" that are discharged from the belt feeder, particles that are not discharged from the original discharge port but are conveyed to the return path while remaining attached to the surface of the downward belt. The packed powder is called "residual powder".

The above-mentioned cleaning work, which is an essential work for many belt feeders, has the risk of the worker's body, clothes, work tools, etc. getting caught in the rotating return roller. In order to avoid danger during this cleaning work, it is effective as a safety measure to surround the return roller on the return path side with, for example, a box-shaped safety fence made of a combination of an outer frame and a wire mesh. However, the "residual granules" that have fallen from the return roller often have a certain viscosity, and these "residual granules" often accumulate inside the safety fence.

If "residual powder and granules" accumulate inside the safety fence, it is necessary to remove the safety fence and perform complicated cleaning work on the safety fence itself, the floor, etc. In this case, it becomes necessary to temporarily stop the operation of the belt feeder and stop the rotation of the return roller. If such a situation occurs frequently, the operating efficiency of the belt feeder decreases, so there has been a need for countermeasures that can balance the safety of cleaning operations with the maintenance of operating efficiency of the device.

Utility Model Publication No. 51-70880 Japanese Patent Application Publication No. 2018-154412

An object of the present invention is to safely perform cleaning work in the area below the return roller on the return path side of a belt feeder that cuts out a fixed amount of powder or granular material without reducing the operational efficiency of the belt feeder. shall be.

The present inventors have discovered that the above problem can be solved by attaching a safety fence having the following configurations to the return roller on the return path side of the belt feeder, and have completed the present invention. Specifically, the present invention provides the following.

(1) It has a conveyor belt that is an endless belt that circulates between two rotating drums, and a return roller that supports the conveyor belt from below while being driven is disposed on the return path of the conveyor belt. The belt feeder has a box-shaped safety fence consisting of a side fence surrounding four sides of the return roller in a rectangular shape and a bottom fence installed in a lower opening surface formed by the side fences. The side fence is made of a mesh-like member at least in a portion excluding the outer frame, and the bottom fence is made of a plurality of rod-like members arranged side by side at intervals, and each of the side fences is made of a mesh-like member. An opening is formed between the rod-like members, and the cross-sectional shape of the rod-like member is circular or semicircular, and when the cross-sectional shape is semicircular, the rod-like member is opened with the curved side facing vertically upward. A belt feeder in which parts are arranged side by side.

According to the belt feeder (1), the area below the return roller on the return path side can be avoided while avoiding the accumulation of "residual powder and granules" inside the safety fence that would force the temporary suspension of belt feeder operation. The cleaning work can be carried out safely without reducing the operational efficiency of the belt feeder.

(2) The belt feeder according to (1), wherein the opening width between the rod-shaped members is 20 mm or more and 100 mm or less.

According to the belt feeder (2), the accumulation of "residual powder and granules" inside the safety fence, which would force the temporary suspension of the belt feeder operation, can be more reliably avoided while the above-mentioned cleaning work can be carried out. , it is possible to reliably prevent the occurrence of accidents in which workers' bodies, clothes, work tools, etc. are caught in the return roller, so the above-mentioned method can be implemented more safely and efficiently without reducing the operating efficiency of the belt feeder. Able to perform cleaning work.

(3) According to (1) or (2), a plurality of openings are formed in a lattice shape in the bottom fence by arranging the plurality of rod-shaped members along two orthogonal directions. belt feeder.

According to the belt feeder (3), the strength of the bottom fence is further improved, the safety of cleaning work in the area below the return roller on the return path side is further increased, and the operating efficiency of the belt feeder is reduced. The above cleaning work can be performed without any trouble.

(4) The belt feeder according to any one of (1) to (3), wherein the mesh member forming the side fence is made of expanded metal.

According to the belt feeder (4), due to the unique shape of expanded metal in which the cross section of the wires that make up the mesh stand up in a diamond shape, "residual powder and granules" are deposited on the side rails. can be suppressed, and the efficiency of the above-mentioned cleaning work can be maintained satisfactorily.

The present invention makes it possible to safely perform cleaning work in the area below the return roller on the return path side in a belt feeder that cuts out a fixed amount of powder or granular material without reducing the operating efficiency of the belt feeder. .

1 is a perspective view schematically showing the overall configuration of a belt feeder of the present invention. FIG. 2 is a side view schematically showing the overall configuration of the belt feeder of the present invention and the mode of cleaning work in the area below the return roller on the return path side. FIG. 2 is a side view schematically showing the structure of a safety fence included in the belt feeder of the present invention. FIG. 2 is a perspective view showing a safety fence installed in the belt feeder of the present invention, viewed diagonally from below. FIG. 2 is a drawing for explaining the structure of the bottom fence of the safety fence installed in the belt feeder of the present invention.

Hereinafter, preferred embodiments of the belt feeder of the present invention will be described. However, the present invention is not limited to the following embodiments. Belt feeders are widely used, for example, as equipment for charging zinc-containing ores such as steel dust and additives such as coke breeze into rotary kilns for reduction roasting in zinc oxide ore manufacturing plants using the Wertz process. ing. The belt feeder of the present invention can also be preferably applied to a zinc oxide ore production plant using the Wertz method. Furthermore, the belt feeder of the present invention is not limited to this, and can be used in various manufacturing plants that carry out a process of charging powder or fine particles.

<Belt feeder>
[overall structure]
FIG. 1 is a perspective view schematically showing the overall configuration of a belt feeder 10 of the present invention. The belt feeder 10 is provided with a conveyor belt 1 that conveys the powder m. Further, at a site where the belt feeder 10 is operated, a shooter 4 for feeding the powder m onto the conveyor belt 1 is often installed. For example, one specific example of such a belt feeder is one in which the conveying capacity is 72 t/h, the maximum running speed of the conveying belt is 5 m/min, the electric motor is 11 kW, and the width of the conveying belt is 700 mm. Note that the running speed of the conveyor belt of a general belt conveyor is about 20 m/min to 100 m/min.

The conveyor belt 1 is a belt-shaped endless belt that circulates between two rotating drums 21 and 22 arranged at the starting end and the terminal end of a conveying path. The conveyor belt 1 uses the rotating drums 21 and 22 as turning points, and travels in one predetermined direction along a circulation path consisting of an upper conveyor path 11 and a lower return path 12. The conveyor belt 1 transports the powder m to the end of the conveyance path 11 by running on the conveyance path 11 with the powder or granular material m, which is an object to be conveyed, placed on its surface. Generally, one of the rotating drums 21 and 22 (eg, rotating drum 21 in FIG. 1) is a driving drum, and the other drum (eg, rotating drum 22 in FIG. 1) is a driven drum.

In order to perform efficient and stable reduction roasting in a zinc oxide ore production plant using the Wertz process, it is necessary to reduce roasting of multiple types of zinc-containing ores such as steel dust, and additives such as coke powder and limestone powder. It is necessary to strictly control the amount charged into the rotary kiln for burning. When the belt feeder 10 is used in a manufacturing plant where strict adjustment of the charging amount is required, it is preferable that the belt conveyor has a drive drum whose rotational speed can be changed, and furthermore, the conveyance path should be More preferably, it is possible to perform feedback control to change the rotation speed of the drive drum based on a weighed value from a load cell type weigher 25 installed at the terminal end of the drive drum.

Below the return path 12 of the conveyor belt 1, a plurality of return rollers 23 and 24 are driven while contacting the lower surface of the conveyor belt 1 in order to support the conveyor belt 1 so as not to bend downward. It is installed in such a way that it rotates.

As shown in FIGS. 1 and 2, in the belt feeder 10 of the present invention, a safety fence 3 is installed surrounding the return rollers 23 and 24. Details of the configuration and functions of the safety fence 3 will be described later.

The shooter 4 is a feeding device for the powder m, which is an object to be transported, and is installed above the transport path 11 of the transport belt 1 . The shooter 4 consists of a hopper part which is a container for temporarily storing the powder m and a chute part which is connected to the lower part of the hopper and discharges the powder m towards the surface of the conveyor belt 1. . The bottom of the chute portion is open, and objects to be transported may spill out on both sides forming opposing long sides when viewed from above, and on the side at the start of the transport path that crosses the traveling direction of the transport belt. It is sealed to prevent it from happening. On the other hand, a discharge port is formed on the side surface of the chute portion at the end of the conveyance path, through which the powder or granular material m can be discharged at a desired discharge speed.

[Safety fence]
As shown in FIGS. 3 and 4, the safety fence 3 is a protective fence having a box-shaped outer shape, and consists of a side fence 31 and a bottom fence 32 joined below the side fence 31. The side rails 31 are installed so as to surround the four sides of the return rollers 23 and 24 in a square shape, and the bottom rails 32 are installed so as to cover the lower opening surface formed by the side rails 31. .

The side fence 31 is constructed using a fence member consisting of a rectangular outer frame and a mesh-like member joined to the inner edge of the outer frame, in order to make the internal state of the safety fence 3 visible from the outside. do. As the mesh member, expanded metal, general wire mesh, punching board, or the like can be used. However, if a wire mesh is used that is coarse enough to be visible, there may be problems such as insufficient strength or time-consuming joining to the inner edge of the outer frame. On the other hand, punched metal has a limited aperture ratio and has a problem with visibility. Furthermore, the increased weight increases the workload during installation and replacement, which is a drawback. Therefore, among the above-mentioned materials, it is particularly preferable to use expanded metal as the mesh-like member constituting the fence member. Alternatively, as long as it has the necessary strength, expanded metal can be used alone as a fence member that also serves as the outer frame. Note that as the expanded metal, known members such as those made of materials and structures disclosed in JP-A No. 2001-47153 can be used as appropriate.

In addition, expanded metal is manufactured by making cuts in a staggered dotted line shape on a steel plate and stretching them, so the elements that make up the mesh are It has the characteristic that the cross section of the wire stands up in a diamond shape. That is, since the corners are sharp, it is difficult for spilled powder to get on it. Therefore, it is advantageous in that it is possible to further suppress the retention and accumulation of "residual powder and granular material" within the safety fence.

The bottom fence 32 installed on the lower opening surface formed by the side fence 31 has a plurality of rod-like members 321 juxtaposed at appropriate intervals, so that the opening width w1 is created between each rod-like member 321. An opening is formed. Further, as shown in FIG. 5, the rod-shaped member 321 is arranged in such a manner that the rod-shaped members 321 and 322 intersect along two directions perpendicular to the vertical and horizontal directions, thereby forming a rectangular opening with a width of w1×w2. may be formed in a grid pattern.

As the rod-shaped member 321 constituting the bottom fence 32, it is preferable to use a rod-shaped member having a circular or semicircular cross-sectional shape. In addition, when using a rod-shaped member having a semicircular cross-sectional shape, it is arranged with its curved surface facing vertically upward. Thereby, accumulation of retained substances on the rod-shaped member 321 can be further suppressed.

Further, the opening width of the opening formed between the rod-shaped members 321 is preferably 20 mm or more and 100 mm or less. If the opening width is less than 20 mm, the "residual powder" tends to stay and accumulate. If it exceeds 100 mm, there is a possibility that the cleaning worker's hands or the tip of the shovel may enter the safety fence and get caught in the return roller.

[Cleaning method]
Also in the belt feeder 10 of the present invention, as shown in FIG. 2, cleaning work by the cleaning worker h is performed in the area below the return rollers 23 and 24, as in the prior art. However, because the safety fence 3 is installed, even if the cleaning work is performed while the belt feeder 10 is in operation, the body, clothes, work tools, etc. of the cleaning worker h will be protected from the rotating return rollers 23, 24. You can eliminate the risk of getting caught. Furthermore, it is less likely that it will be necessary to clean the inside of the safety fence 3 due to retention and accumulation of "residual powder and granular material" inside the safety fence 3. Therefore, cleaning work can be performed efficiently while maintaining the operating rate of the belt feeder and ensuring the safety of the cleaning worker h.

1 Transport belt 11 Transport path 12 Return path 21, 22 Rotating drum 23, 24 Return roller 3 Safety fence 31 Side fence 32 Bottom fence 321, 322 Rod-shaped member 4 Shooter 10 Belt feeder m Powder h Cleaning worker

Claims (4)

The belt has a conveyor belt that is an endless belt that circulates between two rotating drums, and a return roller that supports the conveyor belt from below while being driven is disposed on the return path of the conveyor belt. A feeder,
A box-shaped safety fence is installed, which includes a side fence that surrounds four sides of the return roller in a rectangular shape, and a bottom fence that is installed in a lower opening surface formed by the side fences,
The side fence is made of a mesh-like member at least in a portion excluding the outer frame,
The bottom fence is made up of a plurality of rod-shaped members arranged side by side at intervals, and an opening is formed between each of the rod-shaped members,
The cross-sectional shape of the rod-shaped member is circular or semicircular, and when the cross-sectional shape is semicircular, the rod-shaped members are arranged side by side with their curved surfaces facing vertically upward.
belt feeder. The belt feeder according to claim 1, wherein the opening width between the rod-shaped members is 20 mm or more and 100 mm or less. The belt feeder according to claim 1 or 2, wherein a plurality of openings are formed in the bottom fence in a lattice shape by arranging the plurality of rod-shaped members along two orthogonal directions. The mesh-like member constituting the side fence is made of expanded metal.
The belt feeder according to any one of claims 1 to 3.

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