Conveyor belt tear monitoring and protection device and method, and belt conveyor

Abstract

The present invention relates to the technical field of conveyor belt protection, and discloses a conveyor belt tear monitoring and protection device and method, and a belt conveyor. The conveyor belt tear monitoring and protection device includes: a material collector for gathering materials scattered on the non-working surface of the return belt; the material collector includes two scrapers that are tilted and tightly attached to the non-working surface of the return belt, and the two scrapers form a wide feed opening and a narrow discharge opening; a photoelectric switch includes a signal transmitting end and a signal receiving end, and the signal transmitting end and the signal receiving end are relatively arranged on both sides of the narrow discharge opening; two groups of straight sweepers are arranged on both sides of the material collector and tightly attached to the non-working surface of the return belt; a buffer bed is arranged below the material collector and close to the working surface of the return belt. Through this technical solution, the possibility of the belt being scratched by foreign objects is greatly reduced, which is of great help to safe production, energy saving and environmental protection.

Description

Technical Field

[0001] The present invention relates to the technical field of conveyor belt protection, and in particular to a conveyor belt tear monitoring and protection device and method, and a belt conveyor. Background Art

[0002] Belt conveyors use continuous or intermittent motion of conveyor belts to transport lightweight items or powdered or granular items. They are widely used in mining, electronic plastics, food and light industry, chemical and pharmaceutical industries, and are most commonly used in mining sites, storage yards, and thermal power plants.

[0003] During conveyor belt operation, sharp objects, especially iron plates and rebar, in material handling equipment (such as material carts), hoppers, material yards, and the drop pipes along the conveyor are the primary cause of belt punctures. These punctures typically begin at the buffer bed below the drop pipe connecting the upper conveyor to the lower conveyor and at the belt tensioning device. Once a belt is punctured, by the time workers discover the anomaly, over 90% of the time, the entire belt has been punctured, resulting in significant losses.

[0004] At present, there are many kinds of anti-tear devices for belt conveyors, but their reliability is extremely poor and they cannot truly prevent the belt from being torn by foreign objects. Summary of the Invention

[0005] The inventors found that in enterprises that use conveyor belts for material transportation, there are many cases of belt scratching. Therefore, it is necessary to conduct in-depth research on the problem of belt scratching. After reviewing many belt scratching incidents, it was found that the belt has the following characteristics after being scratched by hard objects: (1) There is no obvious change in the belt conveyor current, and even if there is a sudden change, it is easy to misjudge; (2) The starting point of the scratch is hidden and difficult to detect in the surveillance video; (3) There is a serious accumulation of coal at the tail guard of the belt conveyor; (4) The original anti-tearing device is completely ineffective.

[0006] Because the belt often punctures the buffer bed at the exit of the tail coal drop pipe, hard objects often get stuck in the buffer bed after puncturing the belt, causing the hard object to repeatedly scratch the belt, eventually puncturing the entire belt. Under the influence of the belt's motion characteristics and the weight of the coal, the belt, which has been split into two sections, will gradually separate during its forward movement, and the coal will fall onto the non-working surface of the return belt (return belt), and then flow along the return belt to the tail redirection drum. This is also the reason why excessive coal accumulates in the tail shield in each belt puncture incident.

[0007] To this end, the purpose of the present invention is to provide a belt conveyor tearing monitoring and protection device, which has a reasonable structure, high sensitivity and strong reliability, and can effectively solve the problem of foreign matter in the material tearing the belt.

[0008] In order to achieve the above-mentioned object, the first aspect of the present invention provides a conveyor belt tear monitoring and protection device, comprising:

[0009] A material collector is used to gather materials scattered on the non-working surface of the return belt; the material collector includes two scrapers arranged obliquely and closely attached to the non-working surface of the return belt, the two scrapers forming a wide feeding opening and a narrow discharging opening;

[0010] A photoelectric switch, comprising a signal transmitting end and a signal receiving end, wherein the signal transmitting end and the signal receiving end are arranged opposite to each other on both sides of the narrow discharge opening;

[0011] Two groups of straight sweepers are arranged on both sides of the material collector and close to the non-working surface of the return belt;

[0012] The buffer bed is arranged below the material collector and close to the working surface of the return belt.

[0013] Furthermore, the two scrapers form an angle of 70°.

[0014] Furthermore, the width of the narrow discharge opening is 80mm-100mm.

[0015] Furthermore, the buffer bed is arranged 10 mm away from the working surface of the return belt.

[0016] Furthermore, the photoelectric switch is installed 30 mm away from the non-working surface of the return belt.

[0017] Furthermore, the conveyor belt tear monitoring and protection device also includes a material guide trough installed near the working surface of the outbound belt; the outlet of the material guide trough faces the running direction of the outbound belt.

[0018] Furthermore, taking the photoelectric switch as the reference of 0m, the positions of the outlet of the guide trough and the two groups of straight-line sweepers are 10m, -1.4m, and 20.5m respectively.

[0019] Furthermore, the straight-line cleaner is distributed obliquely relative to the length direction of the return belt.

[0020] At present, most of the research in the field of belt tear prevention is carried out on the upper belt of the belt conveyor. The technical solution of the present invention is to determine whether the belt is scratched by continuously monitoring the amount of coal on the return belt. The technical solution of the present invention is no longer limited to the implementation of tear prevention measures for the upper belt of the belt conveyor. The sensitivity and reliability of tear prevention detection are significantly improved, and the belt conveyor can be stopped in a very short time after the belt is scratched, without causing very serious consequences. Moreover, this device effectively avoids the phenomenon of false operation and false alarm, and will not cause frequent false alarms and false trips of the belt conveyor, and the damage to the motor is relatively small. Through this technical solution, the possibility of the belt being scratched by foreign objects is reduced by more than 90%, which is of great help to safe production, energy conservation and environmental protection, and will produce great safety and economic benefits. It can be extended to the tear prevention of all belt conveyor belts.

[0021] A second aspect of the present invention provides a belt conveyor, which includes the conveyor belt tear monitoring and protection device.

[0022] The third aspect of the present invention provides a conveyor belt tear monitoring and protection method for executing the conveyor belt tear monitoring and protection device, which includes: if the duration of triggering the photoelectric switch is greater than or equal to t, it is regarded as a valid signal and the belt conveyor motor shutdown program is executed; if the duration of triggering the photoelectric switch is less than t, it is regarded as an invalid signal and the belt conveyor motor continues to run.

[0023] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of one embodiment of the conveyor belt tear monitoring and protection device of the present invention;

[0025] Figure 2 It is a structural schematic diagram of an implementation method of a material collector.

[0026] Description of Reference Numerals

[0027] 10 Material collector; 11 Scraper; 12 Wide feed opening; 13 Narrow discharge opening; 20 Return belt; 30 Straight sweeper; 40 Impact bed; 50 Outgoing belt; 60 Material guide chute; 70 Exit. DETAILED DESCRIPTION

[0028] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0029] In the present invention, unless otherwise specified, directional terms such as "upper" and "lower" generally refer to directions in the assembled state. "Inside" and "outside" refer to inside and outside relative to the outline of each component itself.

[0030] It should be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate for the embodiments of the present invention described herein. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or apparatuses.

[0031] The first aspect of the present invention provides a conveyor belt tear monitoring and protection device, such as Figure 1 and Figure 2 As shown, the conveyor belt tear monitoring and protection device includes:

[0032] like Figure 2 As shown, the material collector 10 is used to gather the materials scattered on the non-working surface of the return belt 20. The material collector 10 includes two scrapers 11 that are tilted and tightly attached to the non-working surface of the return belt 20. The two scrapers 11 form a wide feed opening 12 and a narrow discharge opening 13. It should be noted that the scraper 11 is tightly attached to the non-working surface of the return belt 20, but is not fixed to the return belt 20. Such an arrangement of supporting scrapers 11 can be achieved by adding a support frame. In an optional specific embodiment, the width of the narrow discharge opening 13 is set to 80mm-100mm, and the two scrapers 11 form an angle of 70°.

[0033] A photoelectric switch is a type of sensor that can convert changes in the intensity of light between a signal transmitting end and a signal receiving end into changes in current to achieve the purpose of detection. In an optional specific embodiment of the present invention, the photoelectric switch includes a signal transmitting end and a signal receiving end. The signal transmitting end and the signal receiving end are relatively arranged on both sides of the discharge narrow opening 13. Under normal circumstances, it is in a conductive state, and a warning signal is issued when it is blocked by the material. The power supply of the photoelectric switch is connected to the on-site control box of the belt conveyor, and the signal is returned to the on-site control box IO module. In an optional specific embodiment of the present invention, the photoelectric switch is installed 30 mm away from the non-working surface of the return belt 20.

[0034] Two sets of straight-line cleaners 30, commonly used on coal conveyor belts, are used to clean coal lumps from the return belt and prevent them from being drawn into the redirecting roller. The two sets of straight-line cleaners 30 are located on both sides of the material collector 10, close to the non-working surface of the return belt 20. It should be noted that the "two sides" in "two sets of straight-line cleaners 30 are located on both sides of the material collector 10" refer to both sides of the length of the return belt 20. Furthermore, the straight-line cleaners 30 are arranged at an angle relative to the length of the return belt 20 to guide the falling material off the belt.

[0035] The buffer bed 40 is positioned below the material collector 10 and near the working surface of the return belt 20. Its function is to prevent the return belt 20 from falling when a large amount of coal accumulates on the return belt 20. In one embodiment, the buffer bed 40 is positioned 10 mm from the working surface of the return belt 20.

[0036] In addition, the conveyor belt tear monitoring and protection device also includes a first coal drop pipe 81 and a second coal drop pipe 82, which are located above the outbound conveyor belt 50, and a material guide chute 60, which is installed near the working surface of the outbound conveyor belt 50. The outlet 70 of the material guide chute 60 faces the direction of travel of the outbound conveyor belt 50. The material guide chute 60 is also not fixed to the belt, but is located close to or near the outbound conveyor belt 50.

[0037] In an optional specific embodiment, with the photoelectric switch as a reference of 0 m, the positions of the outlet 70 of the guide trough 60 and the two groups of the straight-line cleaners 30 are 10 m, -1.4 m, and 20.5 m, respectively.

[0038] The action process of the tear monitoring protection device is analyzed by simulating that an iron piece pierces the belt and gets stuck on the impact bed at the tail end of the belt conveyor:

[0039] The conveyor belt is 240 meters long and operates at a speed of 3.15 m / s. Conservatively, under an average load of 2,500 t / h, if the belt is scratched for more than 5 meters, the burning coal will propel the crack and fall onto the return belt 20. This crack will then be collected by the material collector 10 and pass through the photoelectric switch, triggering a warning signal. Table 1 shows the time from when the iron material scratches the belt at the buffer bed 40 below the first coal drop pipe 81 and the buffer bed below the second coal drop pipe 82 until the photoelectric switch activates, as well as the length of the belt scratch.

[0040] Table 1 Belt parameters after scratching

[0041] Time(s) Slice length (m) At the buffer bed below the first coal drop pipe 5.448 17.16 At the buffer bed below the second coal drop pipe 3.175 10

[0042] It can be seen from the table that after this device is put into use, if the belt is scratched, the length will not exceed 20m, and the loss will be greatly reduced.

[0043] When installing the belt conveyor tear monitoring and protection device, we carefully considered all possible coal spillage scenarios and environmental impacts. Sweepers are installed at both ends of the device. The upper sweeper on the return belt is located at 20.5 meters to intercept coal flowing from the conveyor head. The lower sweeper, installed at -1.4 meters, intercepts coal spilled after a belt tear and prevents it from being drawn into the belt drum.

[0044] At the same time, a V-shaped roller group is installed at a certain distance from the entrance of the material collector 10 to prevent the coal that falls after the belt is scratched from scattering from the edge of the belt. All the coal is gathered at the material collector 10, making the tear monitoring protection device more sensitive.

[0045] The anti-false alarm adjustment of the tear monitoring protection device is mainly to prevent the photoelectric switch from being actuated by accidental coal particles.

[0046] It's important to note that the installation height of the photoelectric switch is crucial for signal acquisition. When simulating a belt-stripping coal spill, we found that the scattered coal, gathered by the material collector 10, reached a height of 30-40 mm when passing through the photoelectric switch. Therefore, the photoelectric switch should be installed 30 mm above the return belt surface to ensure that the coal flow can be detected.

[0047] Another key issue is how to determine a valid signal. If a coal particle or other foreign object accidentally passes through the device, or if a very small amount of burning coal from the upper belt quickly passes through the collector and triggers the photoelectric switch, it cannot be considered a valid signal of a belt tear. Therefore, after thorough research, the triggering logic of the tear monitoring protection function is set as follows: if a stream of coal ≥525mm long passes through the collector on the return belt, causing the photoelectric switch to continuously activate, it is considered a valid signal. In other words, if the photoelectric switch is continuously blocked for more than 1 / 6 second, it is considered a belt tear, and the belt conveyor motor is shut down. This setting can reduce false alarms by over 90%.

[0048] The above technical solution is different from the existing technology in that most of the research in the field of belt tear prevention is carried out on the upper belt of the belt conveyor. The technical solution of the present invention is to determine whether the belt is scratched by continuously monitoring the amount of coal on the return belt. This device takes a different approach and no longer only implements tear prevention measures on the upper belt of the belt conveyor. The sensitivity and reliability of tear prevention detection are significantly improved, and the belt conveyor can be stopped in a very short time after being scratched, without causing very serious consequences. Moreover, this device effectively avoids the phenomenon of false operation and false alarm, and will not cause frequent false alarms and false trips of the belt conveyor, and the damage to the motor is relatively small. Through this technical solution, the possibility of the belt conveyor being scratched by foreign objects is reduced by more than 90%, which is of great help to safe production, energy conservation and environmental protection, and will produce great safety and economic benefits. It can be extended to the tear prevention of all belt conveyor belts.

[0049] For example, at an inland coal-fired power plant, statistics show that from 2018 to 2022, 15 coal conveyor belts were punctured by foreign objects, an average of 3.75 punctures per year. The replacement cost of each puncture exceeded 100,000 yuan. The implementation of this belt conveyor tear monitoring and protection device is expected to generate approximately 400,000 yuan in economic benefits annually.

[0050] A second aspect of the present invention provides a belt conveyor, which includes the conveyor belt tear monitoring and protection device.

[0051] The third aspect of the present invention provides a conveyor belt tear monitoring and protection method for executing the conveyor belt tear monitoring and protection device, which includes: if the duration of triggering the photoelectric switch is greater than or equal to t, it is regarded as a valid signal and the belt conveyor motor shutdown program is executed; if the duration of triggering the photoelectric switch is less than t, it is regarded as an invalid signal and the belt conveyor motor continues to run.

[0052] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0053] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0054] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A conveyor belt tear monitoring and protection device, characterized in that: include: A material collector (10) is used to gather materials scattered on the non-working surface of the return belt; the material collector (10) comprises two scrapers (11) arranged obliquely and closely attached to the non-working surface of the return belt (20), the two scrapers (11) forming a wide feeding opening (12) and a narrow discharging opening (13); A photoelectric switch, comprising a signal transmitting end and a signal receiving end, wherein the signal transmitting end and the signal receiving end are arranged on both sides of the discharge narrow opening (13) relative to each other, and if the duration of triggering the photoelectric switch is greater than or equal to t, it is regarded as a valid signal; Two groups of straight sweepers (30) are arranged on both sides of the material collector (10) and are closely attached to the non-working surface of the return belt (20); A buffer bed (40) is arranged below the material collector (10) and close to the working surface of the return belt (20); The conveyor belt tear monitoring and protection device further comprises a material guide trough (60) installed near the working surface of the outgoing belt (50); an outlet (70) of the material guide trough (60) faces the running direction of the outgoing belt (50); The straight sweeper (30) is distributed obliquely relative to the length direction of the return belt (20).

2. The conveyor belt tear monitoring and protection device according to claim 1, characterized in that: The two scrapers (11) form an angle of 70°.

3. The conveyor belt tear monitoring and protection device according to claim 1, characterized in that: The width of the discharge narrow opening (13) is 80 mm to 100 mm.

4. The conveyor belt tear monitoring and protection device according to claim 1, characterized in that: The buffer bed (40) is arranged 10 mm away from the working surface of the return belt (20).

5. The conveyor belt tear monitoring and protection device according to claim 1, characterized in that: The photoelectric switch is installed 30 mm away from the non-working surface of the return belt (20).

6. The conveyor belt tear monitoring and protection device according to claim 1, characterized in that: Taking the photoelectric switch as the reference of 0m, the positions of the outlet (70) of the guide trough (60) and the two groups of the straight sweepers (30) are 10m, -1.4m, and 20.5m, respectively.

7. A belt conveyor, characterized in that: The belt conveyor includes the conveyor belt tear monitoring and protection device according to any one of claims 1 to 6.

8. A conveyor belt tear monitoring and protection method for implementing the conveyor belt tear monitoring and protection device according to any one of claims 1 to 6, characterized in that: The protection method includes: if the duration of triggering the photoelectric switch is greater than or equal to t, it is regarded as a valid signal and the belt conveyor motor shutdown program is executed; if the duration of triggering the photoelectric switch is less than t, it is regarded as an invalid signal and the belt conveyor motor continues to run.

Images