JP7139624B2 - Granule hopper and its control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a granular material hopper that continuously discharges granular materials such as coal and gypsum that are intermittently put into the hopper onto a belt conveyor arranged below the hopper, and a control device thereof.

A granular material hopper equipped with a belt conveyor at the bottom is used to continuously supply granular materials such as coal and gypsum to a predetermined location.
This granular material hopper is charged with granular material from a bucket crane, a vehicle, or the like through an upper opening of the hopper. Then, it is continuously discharged onto the belt conveyor under the hopper and supplied and transported to the next process.

In such a granular material hopper, when the granular material is charged into the hopper by a grab bucket or a wheel loader with a bucket, the amount of granular material received in the hopper is not constant and always fluctuates, and the belt at the bottom of the hopper The amount of granules thrown into the conveyor is also not constant. At this time, the cutout amount also varies due to the difference in the ease with which the powder is cut out from under the hopper due to the height of the accumulation in the hopper, the water content of the granular material, the particle size, and the like.
Therefore, a mechanical gate is attached under the hopper for the purpose of making the amount of cut out to the belt conveyor constant (gate structure disclosed in Patent Documents 1 and 2). Conventionally, the amount of waste discharged from the bottom of the hopper was limited by the degree of opening of this gate.

The amount of powder discharged from below the hopper is determined by the movement of the belt conveyor under the hopper to move the powder in contact with the belt conveyor, and the powder in the hopper descends and is discharged.
In the belt conveyor under the hopper, the hopper discharge resistance changes depending on the properties of the granular material (for example, in the case of coal, the type of coal, water content, etc. (varies depending on outdoor storage conditions)). At this time, the electric current value of the driving motor of the belt conveyor becomes high and may automatically trip (trip), which is inconvenient when the belt is conveyed.
For example, if the facility stops with a large amount of powder on the hopper and on the belt conveyor, it may be necessary to remove the powder remaining on the belt conveyor in order to restart the equipment. This work not only lowers productivity due to a decrease in operating time, but is also a complicated manual work, and should be avoided as much as possible in terms of ensuring safety and working environment.

Factors that cause the load on the belt conveyor to fluctuate include the amount of accumulation in the hopper and the properties of the granular material (particle size distribution, viscosity, moisture, etc.). As described above, gate 1 adjusts the amount to be cut out to belt conveyor 2, but the force of belt conveyor 2 movement acts on the granular material in contact with belt conveyor 2, and the maximum compression occurs before gate 1 ( See Figure 6). When the moving force of the belt conveyor exceeds the shear limit of the powder and granular material, the inside of the powder and granular material is sheared and part of the powder and granular material is separated, and the powder and granular material on the belt conveyor side is separated from the belt. It is discharged from below the hopper as the conveyor moves. Immediately after shearing, the compressive force inside the granular material is released temporarily, so the current value decreases. Then, the granular material inside the hopper is discharged while repeating pressurization and release inside the granular material. Next, when the granules are put into the hopper, the same operation as described above is repeated. As an example, after charging once into the hopper, after 7 to 8 times of compression and release, the next granular material is charged. This is repeated below. At this time, the change in compression acting on the inside of the granular material and the behavior of the granular material can be read from the change in the current value of the belt conveyor driving device.

FIG. 7 is a graph showing the relationship between the conventional conveyor drive current value at the bottom of the hopper and time. The vertical axis of the graph indicates current value (amperes), and the horizontal axis indicates time (seconds). When the hopper is empty, the belt conveyor drive current value is about 15 amperes. When the first granules are put into the hopper, the belt drive force compresses the granules in front of the bottom gate of the hopper, causing the current value to rise sharply and reach a peak in about 10 seconds. (A in FIG. 7). Next, the compressive force is temporarily released by shear separation inside the granular material, and the current value momentarily drops. In this way, compression and release are repeated in front of the gate under the hopper. At this time, since there is no sediment in the hopper at the time of initial charging, the load is small and the current value of the belt conveyor driving device is within the range of the rating (38 amperes).

Next, when part of the powder remains in the hopper (current value is 26 amperes), a second bowl of powder is added (B in FIG. 7), and the current exceeds the rated value. The maximum value is 44 amperes. As in the first cup, the granules are discharged from the hopper while repeating the increase and decrease of the current value (repeated internal shearing and opening about 7 times in one cycle) due to shear separation inside the granules. Such behavior is the same in the third cup (C in FIG. 7).
The above current value is an example, and is affected by the amount of hopper deposits and the properties of the powder (particle size distribution, viscosity, moisture, etc.), and the viscosity and particle size that inhibit the fluidity inside the deposit. The relationship between the current value and the time is almost the same, although it is of course different depending on factors such as the particle size distribution.

JP 2017-193391 A Japanese Patent No. 4919381

As described above, conventionally, the conveyor drive current value frequently exceeded the rated value due to the compression resistance of the granular material. As a result, the automatic shutoff (trip) causes the facility to stop, resulting in a significant drop in productivity.
SUMMARY OF THE INVENTION In view of the above-described problems of the prior art, an object of the present invention is to provide a granule hopper and its control device that can continuously and stably dispense granules without overloading the drive section of a belt conveyor. and

As a first means for solving the above-mentioned problems, the present invention is a box-shaped hopper body having openings on the top and bottom surfaces . In the granule hopper that dispenses on the open belt conveyor,
A side wall of the hopper body on the downstream side with respect to the conveying direction of the powder discharged from the lower opening of the hopper body and flowing on the belt conveyor is fan -shaped with an axis centered in a direction perpendicular to the conveying direction . A gate that swings to adjust the discharge amount of the granular material between the lower part of the hopper body and the belt conveyor, and a piston and a cylinder that are connected to the outer surface of the gate are arranged to swing the gate. A cylinder mechanism is provided to apply a reaction force to the moving force of the belt conveyor received during the dispensing operation of the powder or granular material, and to apply the pressing force of the powder or granular material to the gate surface at an angle ,
Provided is a granular material hopper, wherein the main surface of the gate is curved along the conveying direction of the belt conveyor, and the lower end portion on the side of the belt conveyor is provided with continuous unevenness in a sawtooth shape. It is in.
According to the first means, it is possible to reduce the compression resistance of the tip of the gate that comes into contact with the granular material. As a result, the compression resistance of the granular material can be reduced, and a rapid increase in the driving current value of the belt conveyor can be suppressed.

As a third means for solving the above-mentioned problems, the present invention is the powder or granular material according to the first or second means, wherein the gate is provided with unevenness at the end on the belt conveyor side. It is to provide a hopper.
According to the third means, it is possible to avoid the reaction force peak occurring at the tip of the gate.

As a fourth means for solving the above problems, the present invention provides a granular material hopper according to any one of the first to third aspects,
a current measuring unit that measures the driving current of the belt conveyor;
an opening/closing control unit that is electrically connected to the gate and the current measurement unit and controls the degree of opening of the gate so that the measured value of the current measurement unit falls within a set range;
To provide a control device for a granular material hopper characterized by comprising
According to the fourth means, the amount of change in the load when compressing the powder before the gate can be determined from the amount of change in the current value. can promptly respond to

According to the present invention configured as described above, it is possible to reduce the compression resistance at the tip of the gate that comes into contact with the granular material.
In addition, the amount of change in the load during compaction of the powder before the gate can be determined from the amount of change in the current value, and changes in the conveyed material (granules) can be handled more quickly than in the conventional measurement of the discharge amount downstream of the hopper.

It is a structural schematic diagram of the granular material hopper of the present invention. FIG. 3 is a schematic configuration diagram of a granular material hopper of modification 1; FIG. 11 is an explanatory diagram of a granular material hopper of modification 2; 1 is a schematic diagram of the configuration of a control device for a granular material hopper according to the present invention; FIG. It is a graph which shows the relationship between the conveyor drive current value of the hopper lower part of this invention, and time. It is explanatory drawing of the conventional granular material hopper. It is a graph which shows the conventional conveyor drive current value of the lower part of a hopper, and the relationship of time.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a granular material hopper and its control device according to the present invention will be described in detail below with reference to the drawings.

[Particle hopper 10]
FIG. 1 is a schematic diagram of the configuration of the granular material hopper of the present invention. As illustrated, the granular material hopper 10 of the present invention has a hopper body 12, a belt conveyor 14, and a gate 20 as main basic components.
The hopper body 12 is a box-shaped container having openings on the upper and lower surfaces, and the upper opening is wider than the lower opening. Along with this, the hopper main body 12 has a side wall formed in a diameter-expanding shape from the bottom to the top to facilitate filling of the granules.
The belt conveyor 14 has a conveying surface facing the lower opening of the hopper main body 12 with a predetermined gap therebetween, and conveys the granular material falling from the hopper main body 12 to a predetermined location in the post-process.
The gate 20 is attached to the side wall on the downstream side of the hopper body 12 to adjust the discharge amount of the granules. The main surface of the gate 20 of this embodiment is curved along (toward) the conveying direction of the belt conveyor 14, in other words, it is formed in an arc shape extending outward from the side wall of the hopper body in a side view. The gate 20 is attached to the side wall on the downstream side of the hopper body 12 via a rotation support portion 22 . The rotation support part 22 has an axial center arranged in a direction perpendicular to the conveying direction of the belt conveyor, and supports the arc-shaped gate 20 so as to be rotatable in a fan shape (in a direction toward or away from the conveyor). A cylinder mechanism 50 is attached to the gate 20 to give a reaction force to the moving force of the belt conveyor 14 received during the work of discharging the granular material (the same applies to FIG. 2 described later).

In the granule hopper 10 having such a configuration, the granule conveying force of the belt conveyor acts at right angles to the flat plate-shaped gate (perpendicular to the conveyor surface) along the side wall of the hopper body of the conventional configuration. The edge of the gate serves as a shear (plane) line inside the compressed granular material, and compared to the concentration of stress inside the granular material that causes transport resistance, the compression concentration at the tip of the gate can be alleviated. In other words, by causing the pressing force of the granular material acting in the direction perpendicular to the gate to be applied with an inclination to the gate surface, a vector in the downward direction (diagonally downward direction) is generated and the gate reaction force is alleviated. . Therefore, while maintaining the original function of the gate to limit the amount of powder on the belt conveyor by scraping, the compression resistance at the tip of the gate in contact with the powder is reduced, and the powder at the tip of the gate is sheared. and the load current value of the belt conveyor can be reduced.

FIG. 2 is a schematic diagram of the configuration of the granular material hopper of Modification 1. As shown in FIG. As shown in the figure, the powdery or granular material hopper of Modification 1 has the downstream side wall of the hopper main body 12A curved along (toward) the conveying direction of the belt conveyor 14, in other words, formed into an arc shape that spreads outward when viewed from the side. is doing. The gate 20A is formed in a flat plate shape. The gate 20A is attached to the downstream side wall of the hopper main body 12 via the rotation support portion 22 similar to that shown in FIG.
The same effects as those of the configuration shown in FIG. 1 can be obtained by the granular material hopper of the first modification.

FIG. 3 is an explanatory diagram of a granular material hopper of Modification 2. FIG. As shown in the drawing, the granular material hopper of Modification 2 has unevennesses 24 at the end (lower end) of the gate 20 (20A) on the side of the belt conveyor. The unevenness 24 is continuously formed in a sawtooth shape at the lower end of the gate.
A gate with such unevenness can avoid a reaction force peak occurring at the tip.

[Control device 30 for granular material hopper]
FIG. 4 is a schematic diagram of the configuration of the granular material hopper control device of the present invention. As shown in the figure, the granular material hopper control device 30 of the present invention is mainly composed of the aforementioned granular material hopper 10, the drive current measuring section 40, the cylinder mechanism 50 of the gate, and the opening/closing control section 60. there is
The driving current measuring unit 40 is attached to the driving unit (electric motor) of the belt conveyor 14 and can measure the driving current value (amperes).
The gate cylinder mechanism 50 swings the gate 20, in other words, opens and closes the damper-like gate, and an electric, hydraulic, pneumatic, or electromagnetic drive source can be applied.

The open/close control unit 60 is electrically connected to the drive current measurement unit 40 and the cylinder mechanism 50 . The opening/closing control unit 60 feedback-controls the opening degree of the gate 20 according to the drive current value in order to perform stable operation so that the drive current value of the belt conveyor 14 does not exceed the rated value. That is, the gate 20 is temporarily opened when the reaction force generated in the gate 20, which is the reaction force of the belt conveying force, exceeds the limit value.

[Method for controlling powder hopper]
A control method using the granular material hopper control device of the present invention configured as described above will be described below.
FIG. 5 is a graph showing the relationship between the conveyor drive current value for the lower part of the hopper and time according to the present invention.
With the hopper body empty, the first granules are put in and the driving current value of the belt conveyor is measured. In the graph of FIG. 5, the current increases by 20 amperes from 15 amperes to 35 amperes in about 10 seconds (one-dot dashed line). Here, the opening degree of the gate is set in advance step by step as follows. If the drive current value rises by 5 amperes or more (within 3 seconds), the gate opening is set to 1. If the drive current value rises by 5 amperes or more (within 3 seconds), the gate opening is set to 2, and the drive current value rises by 5 amperes or more. (Within 3 seconds), the gate opening degree is set to 3.
On the other hand, when the gate is closed, it is set in three steps, which is the reverse of the case where the gate is opened step by step. It should be noted that the decision to close the gate is made in the closing direction in consideration of the state of the drive current value, since the conveying amount of the belt conveyor increases. As a result, it is possible to operate up to near the maximum conveying capacity of the belt conveyor.

The opening/closing control unit 60 arbitrarily sets the opening degree of the gate (such as the above-mentioned gate opening degree 1 to 3) from the transition of the driving current value for the first cup of the powder, and the measured value of the driving current measuring unit 40 is The opening of the gate is controlled via the cylinder mechanism 50 so that it falls within the set range (below the rated value). As shown by the solid line in the graph of FIG. 5, by setting the opening degree of the gate in this manner, the drive current peaks at about 30 amperes when the first bowl of powder is added, and the drive current value peaks at about 30 amperes when the second bowl is charged. The current value peaks at about 35 amperes, and the drive current value peaks at about 36 amperes after the third bowl is thrown, enabling control within the set range (below the rated value).
According to the granular material hopper control device of the present invention, the amount of change in the load at the time of compressing the granular material in front of the gate can be determined from the amount of change in the current value. It can respond quickly to changes in materials (granules).

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present invention.
Moreover, the present invention is not limited to the combinations shown in the embodiments, and can be implemented in various combinations.

10 …… Granular material hopper, 12, 12A …… Hopper body, 14 …… Belt conveyor,
20, 20A......gate, 22......rotation support part, 24......unevenness,
30 ...... Control device for granular material hopper,
40 …… drive current measuring unit,
50 …… Cylinder mechanism,
60: An opening/closing control section.

Claims (2)

In a powdery or granular material hopper that feeds powdery or granular material from the upper opening of a box-shaped hopper body having openings on the top and bottom surfaces and discharges it onto a belt conveyor arranged at a predetermined distance from the lower opening of the hopper body,
A side wall of the hopper body on the downstream side with respect to the conveying direction of the powder discharged from the lower opening of the hopper body and flowing on the belt conveyor is fan -shaped with an axis centered in a direction perpendicular to the conveying direction . A gate that swings to adjust the discharge amount of the granular material between the lower part of the hopper body and the belt conveyor, and a piston and a cylinder that are connected to the outer surface of the gate are arranged to swing the gate. A cylinder mechanism is provided to apply a reaction force to the moving force of the belt conveyor received during the dispensing operation of the powder or granular material, and to apply the pressing force of the powder or granular material to the gate surface at an angle ,
A granular material hopper, wherein the main surface of the gate is curved along the conveying direction of the belt conveyor, and a continuous serrated unevenness is provided at the lower end on the side of the belt conveyor. The granular material hopper according to claim 1;
a driving current measuring unit for measuring the driving current of the belt conveyor;
an opening/closing control unit electrically connected to the gate and the driving current measuring unit and controlling the opening degree of the gate so that the measured value of the driving current measuring unit falls within a set range;
A control device for a granular material hopper, comprising:

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