Belt conveyor belt longitudinal tear early detection system

Abstract

This system provides a detection system for longitudinal belt tearing in a belt conveyor that can provide early information, immediately stop operation, and minimize belt tearing. [Solution] A detection wire 2 is stretched directly below the belt B along the carrier-side roller C of the downstream belt conveyor A2 of the loading section of the belt conveyor, and connecting wires 3 and 4 are stretched near the side of the belt B. The detection wire 2 and the connecting wires 3 and 4 are connected by a detachable connector 1 that detaches when tension is applied, forming a single loop closed circuit, a first circuit X, and a second circuit Y that supplies power to the first circuit X. The system is configured such that the second circuit Y detects that the first circuit X has been cut when the detection wire 2 is cut or the detachable connector 1 comes off due to contaminants T in the conveyed material S, and then issues an appropriate alarm.

Description

Technical Field

[0001] This invention relates to a detection system capable of early detecting a longitudinal tear of a conveyor belt for conveyance.

Background Art

[0002] For example, in a loading section where transfer is made from an upstream conveyor belt to a downstream conveyor belt, sharp contaminants such as sharp metal pieces or ores may fall while being mixed in the conveyed material.

[0003] And even if the downstream conveyor belt is penetrated by such sharp contaminants as metal pieces or ores, it will move in the belt traveling direction together with the conveyed material and the belt as it is.

[0004] Then, the piercing sharp contaminant tries to stay when it hits the front carrier roller by further advancing with the belt, but since it is pushed by the belt, as a result, it will tear the belt in the traveling direction, that is, vertically.

[0005] Due to the longitudinal tear of the belt caused thereby, the operation of many facilities including the conveyor belt has to be stopped, resulting in a large cost for belt repair or replacement, or causing great damage to the operation.

[0006] Various methods have been proposed to prevent this. Many of the known longitudinal tear detection methods were to remove the causes and factors of longitudinal tearing. For example, regardless of the presence or absence of sharp contaminants such as metal pieces or ores in the conveyed material, either detection or removal is performed by strong magnetic force during all conveyance or during transfer from the upstream side to the downstream conveyor.

[0007] Generally, iron fragment separators or metal fragment detectors are used, but in both cases, the fragments may move downstream without being detected. Furthermore, this method has the drawback of not being applicable to hard, sharp ores other than inclusions with properties such as metals that are attracted by magnetism.

[0008] Separately, there is also a known method for detecting a longitudinal tear in a conveyor belt by detecting when a sharp metal fragment or ore falling along with the conveyed material penetrates and cuts a liquid or wire sealed inside a glass tube attached near the underside of the downstream conveyor belt (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Public Gazette No. 52-51432 [Patent Document 2] Japanese Public Gazette No. 53-34718 [Overview of the project] [Problems that the invention aims to solve]

[0010] Incidentally, the detection system described in Patent Document 1 is a longitudinal crack detection device that uses a glass tube and employs a method of electrically activating the conveyor drive based on changes in the level of the liquid sealed inside the glass tube.

[0011] However, because the factors that stop the belt's movement include not only the breakage of the glass tube but also the flow of the liquid filled in the glass tube, the structure becomes complicated, inevitably leading to a significant increase in costs, as well as problems such as the considerable effort required for equipment damage and subsequent repair.

[0012] Furthermore, as described in Patent Document 2, in the case of a wire sealed inside a glass tube, even if a sharp object that pierces the conveyor belt penetrates and shatters the glass tube, and then cuts the internal wire, it is easy to imagine that the subsequent conditions near the site would become extremely dangerous, and that restoring the system would require considerable time and effort.

[0013] Furthermore, the handling of the glass tube itself, the storage of spare parts, and the delicate nature of installation made it a potentially dangerous piece of equipment, which is likely why it never reached practical use.

[0014] This invention provides a system for detecting longitudinal tearing of a belt conveyor that solves the above-mentioned problems, enables early and timely information provision to maintenance personnel on the machine side and remote operation management offices, allows for immediate operation stoppage, and minimizes longitudinal tearing of the belt. [Means for solving the problem]

[0015] To solve the above problems, this invention provides a belt conveyor belt longitudinal tear early detection system characterized by the following: in a loading section where a transfer from an upstream belt conveyor to a downstream belt conveyor takes place, carrier-side rollers are provided at the tail portion of the transfer section of the downstream belt conveyor to support the underside of multiple rows of carrier-side belts arranged in parallel in the upstream direction; a detection wire is stretched along each of these carrier-side rollers directly beneath the belt; a connecting wire is stretched near the side of the belt along the direction of belt flow; the detection wire and the connecting wire are connected by a detachable connector that detaches when tension is applied to form a first circuit which forms a single loop closed circuit; a second circuit is provided to supply electricity to this first circuit; and when the detection wire is cut or the detachable connector comes off due to contaminants in the conveyed material in the loading section, thereby interrupting the loop closed circuit of the first circuit, the second circuit is configured to detect the break in the first circuit and issue an appropriate alarm. [Effects of the Invention]

[0016] As described above, according to the belt longitudinal crack early detection system of the belt conveyor of this invention, when a sharp foreign object pierces the conveying side belt and causes a longitudinal crack in the belt, timely and leak-free information can be provided to maintenance personnel on the machine side, operation management offices at remote locations, etc., and an immediate operation stop is possible, providing a system that minimizes belt longitudinal cracks.

[0017] Also, this invention detects whether a plurality of installed detection conductors are energized based on two-stage judgment criteria, and determines whether a longitudinal crack has occurred in the belt conveyor, enabling early detection of belt longitudinal cracks without discovery omissions.

[0018] Furthermore, it is only necessary to lay a conductor (detection conductor) along the carrier roller directly under the belt, and since members that require delicate handling such as glass tubes are not used, inspection, replacement work of members, and storage of spare parts are also facilitated.

Brief Description of the Drawings

[0019] [Figure 1] Schematic diagram of the belt longitudinal crack early detection system of the belt conveyor of this invention. [Figure 2] Front view of the belt longitudinal crack early detection system of the belt conveyor of this invention. [Figure 3] Plan view of the belt longitudinal crack early detection system of the belt conveyor of this invention. [Figure 4] Plan view of the belt longitudinal crack early detection system of the belt conveyor of this invention. [Figure 5] Chart diagram of the longitudinal crack early detection system of the belt conveyor of this invention. [Figure 6] Side view of the belt conveyor using this invention. [Figure 7] Exploded side view of the belt conveyor using this invention. [Figure 8] Side view of the belt conveyor using this invention. [Figure 9]Plan view of the belt conveyor using this invention. [Figure 10] Plan view of other embodiments.

Embodiments for Carrying out the Invention

[0020] Hereinafter, embodiments of this invention will be described based on the accompanying drawings. Although the outline of the embodiment will be described, it is merely a basic concept, and the equipment and methods used do not have to be limited to those of the embodiment.

[0021] The concept of the belt longitudinal splitting early detection system of this invention is generally composed of an energization circuit of a first circuit X and a second circuit Y, as shown in FIG. 1. Although the figure shows the case where the main power supply 6 serving as the supply power source is an AC power source, a DC power source may also be directly used.

[0022] It is composed of a plurality of small loop units with two sets of existing carrier idlers (a general term for stands with carrier side rollers C) as one set. For each of these carrier side rollers C, a detection wire 2 along the carrier side roller C is stretched directly below the belt B, and a connecting wire 3 along the flow direction of the belt B is stretched near the side of the belt B. The detection wire 2 and the connecting wire 3 are connected by a detachable connector 1.

[0023] As the detachable connector 1, one that can hold the connection of both wires but naturally detaches when a certain amount of tension is applied is used. For example, a member that fits in a linear manner with non-return irregularities, etc. for connection can be considered.

[0024] Also, the detection wires 2 of small units with two sets as one set are similarly connected to the connecting wire 3 and the detachable connector 1, and the detection wires 2 at distant positions of both sets are connected by a longer connecting wire 4, so that the two sets of units are connected to form a single loop closed circuit to constitute the first circuit X.

[0025] By connecting the wires 3 or 4 as described above to form a large loop unit, a wide detection area can be monitored with a single control panel.

[0026] Alternatively, even in a wide loading area, by wiring the system to form loops that appropriately divide each section so that it can detect when the electrical or information signal is interrupted for each group, it would be possible to instantly determine the approximate location on the belt where a sharp object has become lodged.

[0027] The second circuit Y, which is connected to the first circuit X by connection terminal 5, is supplied with AC power from the main power supply 6. However, the power supply is not limited to AC; a multi-power supply system including a battery system is also possible. If necessary, a power transformer (voltage transformer 7), an electromagnetic switch 12 including an AC / DC converter 11, or a frequency converter can be installed to separate the AC power supply that operates the electromagnet 8 from the DC power supply that only detects the disconnection of the detection conductor 2. This makes the system safer and easier to handle in terms of protection against electrical leakage, etc.

[0028] It is also possible to integrate the second circuit Y, which includes the changeover switch 9, into the machine-side control panel 17 housed within the control panel, but this is not required.

[0029] Furthermore, on the second circuit Y side, power is constantly supplied to the first circuit X side as long as the main power supply 6 is energized. When the first circuit X is disconnected, the electromagnet 8 built into the power supply circuit of the second circuit Y turns OFF, and the changeover switch 9 is activated by a coil spring, which in turn activates various alarm devices 10 housed in the control panel within the power supply circuit of the second circuit Y side.

[0030] Specifically, the alarm means 10 is used for signals for parts that warn by lighting or flashing, signals for parts that warn by sound, or signals that emit GPS location information so that the location can be determined from any position.

[0031] As described above, if there is a break in the power supply circuit on the first circuit X side, the coil spring of the changeover switch 9 acts, energizing the various alarm parts, which are the alarm means 10 in the power supply circuit on the second circuit Y side, and causing them to activate instantaneously. This sends out information to the external operation control unit and maintenance personnel that an abnormality has occurred, namely a vertical tear in the belt.

[0032] Next, we will explain what happens when a vertical tear actually occurs in the belt. As shown in Figure 2, in the loading section where the upstream belt conveyor A1 is transferred to the downstream belt conveyor A2, sharp metal fragments or pointed contaminants T, such as ore, may fall into the conveyed material S. Even if these pointed contaminants T penetrate the belt B of the downstream belt conveyor A2, they continue to move in the direction of belt travel along with the conveyed material S and belt B.

[0033] As a result, the contaminant T moves along the belt B and attempts to stop by hitting the roller C on the front carrier side, but because it is pushed by the belt B, it ends up cutting through the belt B in the direction of movement, that is, lengthwise.

[0034] As the first stage of the check, as shown in Figure 3, the detection wire 2 is bent by the contaminant T, and eventually the detection wire 2 breaks (cuts).

[0035] Then, within the second circuit Y, the changeover switch 9, which had been attracted by the electromagnet 8, is released by the coil spring, and the electrical contacts switch to the secondary energized circuit, causing the alarm device 10 to activate.

[0036] Next, the second stage check is an additional check mechanism in case the detection wire 2 passes through in the first stage without breaking (cutting).

[0037] As shown in Figure 4, when the detection wire 2 moves to its limit in the direction of belt travel along with the sharp object T, one of the detachable connectors 1 connecting each detection wire 2 to the connecting wires 3 or 4 is eventually pulled out and detached. This interrupts the power supply to the first circuit X, just as in the first stage when the detection wire 2 breaks, causing the coil spring type changeover switch 9 in the second circuit Y to activate, switching the power supply circuit and activating the alarm means 10.

[0038] As described above, the system ensures complete detection of longitudinal tearing of the belt due to contaminants T through a first-stage check involving the cutting of the detection wire 2 and a second-stage check involving the detachment of the removable connector 1. The flow sheet for this system is shown in Figure 5.

[0039] Next, a specific example of installing the detection wire 2 of this invention will be described. Figure 6 is a side view of a trough-type carrier idler using a belt longitudinal tear early detection system, with a fixed trough angle.

[0040] In this case, the support frame 13, which is divided into three parts, is formed into a trough shape using the fixing devices 16 attached to the support columns on both sides of the carrier idler stand, and also using the inner support column, and is fixed with fasteners. By holding the detection wire 2 in this support frame 13, the detection wire 2 can be fixed to the back surface of the belt B in accordance with the arrangement shape of the carrier-side roller C, that is, the shape of the belt B.

[0041] Next, Figures 7 and 8 show an example of installation on a carrier idler in which the trough angle can be freely adjusted by changing the outer mounting position of the carrier-side rollers C on both sides. As shown in Figure 7, the fixing device 16a attached to the support columns on both sides has an arc-shaped elongated hole.

[0042] Furthermore, the support frame 13 is designed so that the mounting angle of the support frames 13 connected to both sides can be freely adjusted by making the lower part of the mounting holes on both sides of the central support frame 13 into arc-shaped elongated holes. The detection wire 2 is connected to the support frame 13 at multiple points via the support 15.

[0043] Figures 8 and 9 show the support frame 13 of Figure 7 connected to the carrier idler. This allows for variable adjustment to match the trough angle of the carrier-side roller group C, making it possible to maintain a constant gap between the belt B, which matches the belt shape, and the detection wire 2.

[0044] In the above embodiment, the first circuit X, consisting of the detection wire 2, is based on the first circuit X side, which consists of two rows as a set. In some cases, a combination of multiple rows, which is a combination of multiple units of two rows each, may also constitute the first circuit, and the number of rows should be determined according to the conditions of the installation location.

[0045] For example, Figure 10 shows an example where two rows are configured as a single first circuit, and these are connected to a second circuit via the machine-side control panel 17. While this narrows the detection range of a single circuit, it also has the advantage of allowing for more precise identification of the location where a longitudinal tear in the belt has been detected.

[0046] Although various embodiments of the belt conveyor belt longitudinal tear early detection system of this invention have been described above, this invention is not limited to the embodiments described above, and can be implemented with appropriate modifications within the scope of the objective of this invention. [Explanation of Symbols]

[0047] A1 Upstream belt conveyor A2 Downstream belt conveyor B Belt C Carrier side roller S Conveyed items T-contaminants X 1st circuit Y 2nd circuit 1. Detachable connector 2. Detection wire 3,4 Connecting conductor 5 Connection terminals 6 Main power supply 7 Transformer 8 Electromagnet 9. Changeover switch 10 Alarm means 11 AC / DC Converters 12 Electromagnetic switch 13. Support Frame 15 Support 16,16a Fixture 17. Machine-side control panel

Claims

[Claim 1] A belt conveyor belt longitudinal tear early detection system is characterized in that, in the loading section where a transfer takes place from an upstream belt conveyor to a downstream belt conveyor, carrier-side rollers are provided at the tail portion of the transfer section of the downstream belt conveyor to support the underside of multiple rows of carrier-side belts arranged in parallel in the upstream direction, a detection wire is stretched along each of these carrier-side rollers directly beneath the belt, and a connecting wire is stretched near the side of the belt along the direction of belt flow, and the detection wire and the connecting wire are connected with a detachable connector that detaches when tension is applied to form a first circuit that forms a single loop closed circuit, a second circuit is provided to supply electricity to this first circuit, and when the loop closed circuit of the first circuit is interrupted due to contamination in the conveyed material in the loading section, the second circuit is configured to detect the breakage of the first circuit and issue an appropriate alarm.

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