Belt conveyor sliding blockage control system and control method

Abstract

The invention relates to the technical field of belt conveyors, in particular to a belt conveyor sliding blockage control system and method.The belt sliding nozzle outer cover is sequentially provided with a first-stage leaking stoppage detection device and a second-stage leaking stoppage detection device from bottom to top; the detection door is opened towards the outer side through the rotating shaft under the extrusion action of ore; and if the first-stage leakage stoppage detection device does not detect the collected ore, the collected ore in the belt chute rises, and when the collected ore touches a turning plate of the second-stage leakage stoppage detection device, the turning plate turns over, the second rotating shaft rotates, the extension pipe rotates, and the steel wire pull rope is tensioned. The device has the advantages that two-stage detection is adopted, a first-stage leakage stoppage detection device is used for low-position detection, a detection door 4 + counterweight iron 8 is arranged below a belt sliding nozzle, triggering can be carried out in the initial stage of material blockage, and materials are prevented from being accumulated too high; a turning plate 9 and a second leaking stoppage switch 14 are arranged above a belt sliding nozzle to serve as redundancy protection, and it is guaranteed that the belt can still be reliably stopped when the first-stage leaking stoppage detection device fails.

Description

Technical Field

[0001] This invention relates to the field of belt conveyor technology, and in particular to a belt conveyor blockage control system and control method. Background Technology

[0002] In industries such as mining, metallurgy, and chemicals, belt conveyors are widely used for transporting minerals, raw materials, and finished products. However, during the conveying process, due to factors such as uneven ore particle size, changes in moisture content, foreign matter contamination, or unreasonable chute design, the conveyor's discharge chute (i.e., the unloading port) is prone to blockage. If blockage is not detected and addressed promptly, it may lead to the following serious consequences:

[0003] 1. Material overflow (overstocking):

[0004] When the chute becomes clogged, the material cannot be discharged smoothly and accumulates inside the chute, eventually overflowing from the equipment gaps, polluting the environment and increasing cleaning costs.

[0005] 2. Belt damage:

[0006] Accumulated material may scratch the belt, or even cause the belt to run off track or tear, affecting the life of the equipment;

[0007] 3. Production line shutdown chain:

[0008] If blockages are not addressed in a timely manner, they may force upstream equipment to shut down, affecting overall production efficiency.

[0009] Currently, belt conveyor blockage detection devices are mainly divided into two categories: contact type and non-contact type, but both have certain limitations:

[0010] 1. Contact detection (such as rotary paddle level switches) involves mechanical blades contacting the material. When material accumulates and obstructs the rotation of the blades, a switch signal is triggered. However, this method has several drawbacks: in mining environments, large pieces of ore or high-hardness materials can easily damage the mechanical parts, resulting in poor durability; dusty or humid environments can cause the mechanism to jam or malfunction; and frequent maintenance can negatively impact production efficiency.

[0011] 2. Non-contact detection (such as microwave level switches and ultrasonic sensors) uses microwaves, ultrasound, or lasers to detect the material height. When the material reaches a set threshold, a signal is output. However, there are some drawbacks in its use: in mining environments, dust, vibration, and large pieces of ore may interfere with the detection accuracy; the installation location is limited and it is difficult to adapt to complex working conditions. Summary of the Invention

[0012] The purpose of this invention is to provide a belt conveyor blockage control system and control method that can accurately detect blockage in the early stages and reduce malfunctions through logical judgment (such as time delay filtering) to ensure the stable operation of the belt conveyor system.

[0013] To achieve the above objectives, the present invention provides the following technical solution:

[0014] A belt conveyor clogging control system includes a belt 1, a belt 2, and a belt chute cover. The belt 1 is located above the belt 2 and the belt 2 is used to receive the material from the belt 1. The system also includes a primary leak detection device and a secondary leak detection device. The belt chute cover is provided with the primary leak detection device and the secondary leak detection device from bottom to top. The primary leak detection device includes a rotating shaft 5, a detection gate 4, and a leak-stop switch 7. The side arm of the belt chute cover has a square hole located between the drive wheel of the belt 1 and the tail pulley of the belt 2. The rotating shaft 5 is fixed on the outer side wall of the belt chute cover and located above the square hole. The detection gate 4 is hinged to the rotating shaft 5. The leak-stop switch 7 is fixedly connected to one side of the square hole. The leak-stop switch 7 is used to detect the position signal of the detection gate 4. The size of the detection gate 4 is larger than the size of the square hole.

[0015] The leak-stopping switch 1 and 7 are connected to the secondary leak-stopping detection device and the control unit.

[0016] The secondary leak detection device includes a flap 9, a second rotating shaft 11, an extension tube 12, and a second leak-stopping switch 14. Both sides of the belt chute cover have an opening 10. The second rotating shaft 11 passes through the opening 10. The flap 9 is fixedly connected to the second rotating shaft 11. One end of the extension tube 12 is fixedly connected to one end of the second rotating shaft 11. The extension tube 12 is located on the outside of the belt chute cover. The other end of the extension tube 12 is connected to one end of the steel wire rope 13. The other end of the steel wire rope 13 is connected to the second leak-stopping switch 14. The second leak-stopping switch 14 is fixedly connected to the foundation of the belt.

[0017] Leak-stopping switch 1 (7) and leak-stopping switch 2 (14) are connected to the control unit.

[0018] The primary leak detection device also includes a counterweight 8, and the lower part of the detection door 4 is fixed with a counterweight 8.

[0019] The belt spout cover above the square hole is fixed with two nuts, and the rotating shaft 5 passes through the two nuts, so that the detection gate 4 completely covers the square hole.

[0020] Leakage stop switch 17 is a door limit switch.

[0021] The two ends of the rotating shaft 11 are equipped with baffles to prevent the rotating shaft 11 from falling off.

[0022] Leakage-stopping switch 214 is a deviation switch.

[0023] The control unit includes a PLC, which includes a digital input module. The digital input module is connected to the leak-stopping switch 7 and the leak-stopping switch 14 via ports.

[0024] A method for controlling belt conveyor blockage includes:

[0025] S1. When there is no ore collection inside the belt conveyor chute:

[0026] Level 1 Leak Detection Device:

[0027] The detection door 4 is closed under the action of the counterweight 8, and does not contact the leak-stopping switch 7. The normally closed contact of the leak-stopping switch 7 is closed.

[0028] Two-stage leak detection device:

[0029] Flip plate 9 is vertical, rotating shaft 11 is not rotating, extension tube 12 is vertical, steel wire rope 13 is not tightened, and the normally closed contact of leak-stopping switch 14 is closed.

[0030] S2. When there is ore collected inside the conveyor chute:

[0031] Minerals will accumulate from the bottom up. When the height of the accumulated minerals exceeds the detection gate 4 of the first-level leak detection device, the detection gate 4 will open outward through the rotating shaft 5 due to the squeezing action of the minerals. The control unit receives the normally closed contact disconnection information of the leak-stopping switch 7 and sends a command to stop the belt.

[0032] If the primary leak detection device does not detect the ore collection information, the ore collection in the belt chute will rise. When the ore collection touches the flap 9 of the secondary leak detection device, the flap 9 will flip, the shaft 11 will rotate, the extension tube 12 will rotate, the steel wire rope 13 will tighten, and the control unit will receive the information that the normally closed contact of the leak-stopping switch 14 is open and send a command to stop the belt.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. Two-stage detection: The first-stage leak detection device is a low-level detection: a detection gate 4 and a counterweight 8 are installed below the belt chute, which can be triggered at the initial stage of material blockage to prevent material from accumulating too high; a flap 9 and a leak-stopping switch 2 14 are installed above the belt chute as redundant protection to ensure that the belt can still be reliably stopped if the first-stage leak detection device fails; 1.5-second delay filtering: short-term interference signals such as ore impact are filtered by PLC logic, and the belt is only triggered to stop when the blockage signal lasts for more than 1.5 seconds, which greatly reduces the probability of false stop.

[0035] 2. Mechanical structure anti-interference: It adopts a U-shaped threaded steel shaft + counterweight iron, which is resistant to ore impact and dust adhesion; the flip plate + pull rope mechanism has no precision electronic components, avoiding failure caused by vibration and moisture; compared with microwave / ultrasonic sensors, the mechanical structure is simple and maintenance only requires cleaning or replacing worn parts.

[0036] 3. Early warning and low-level priority detection: The primary detection point is located below the belt drive pulley, which can be triggered at the initial stage of material blockage, preventing material from accumulating on the top of the belt or chute. It can not only stop the faulty belt, but also interlock to stop upstream equipment (such as the feeder) to prevent the blockage from spreading; real-time alarm through the SCADA system shortens the fault handling time.

[0037] 4. Compatible with multiple control modes, local / remote dual mode. Local mode: operated via on-site buttons, suitable for maintenance or debugging; Remote mode: integrated into SCADA system for centralized monitoring. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the belt conveyor blockage control system when there is no material blockage at the belt chute.

[0039] Figure 2 This is a schematic diagram of the belt conveyor blockage control system when material blockage occurs at the belt chute.

[0040] Figure 3 This is a schematic diagram of the state of the secondary leak detection device inside the belt conveyor when no material blockage occurs.

[0041] Figure 4 This is a schematic diagram of the status of the secondary leak detection device inside the belt conveyor when material blockage occurs.

[0042] Figure 5 This is the schematic diagram of the electrical control system for a belt conveyor.

[0043] Figure 6 This is a schematic diagram of PLC input and output.

[0044] Figure 7 Flowchart of belt conveyor blockage control method.

[0045] In the diagram: 1. Belt 1; 2. Belt spout cover; 3. Square hole; 4. Detection door; 5. Shaft 1; 6. Nut; 7. Leak-stopping switch 1; 8. Counterweight; 9. Flip plate; 10. Opening; 11. Shaft 2; 12. Extension tube; 13. Steel wire pull rope; 14. Leak-stopping switch 2; 15. Baffle; 16. Belt 2; 17. Drive wheel of Belt 1; 18. Rear pulley of Belt 1; 19. Drive wheel of Belt 2; 20. Rear pulley of Belt 2. Detailed Implementation

[0046] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0047] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.

[0048] Example 1

[0049] A factory has 31 belt conveyors in its large-scale process. The factory is upgrading the belt conveyors to prevent leaks and blockages. Taking one of the low-voltage motor-driven belt conveyors as an example... Figures 1-4 A belt conveyor clogging control system includes a belt 1, a belt 2 16, a belt chute cover 2, a primary leak detection device, and a secondary leak detection device. Belt 1 is positioned above belt 2 16 and receives material from belt 1. The belt chute cover 2 is equipped with a primary leak detection device and a secondary leak detection device, arranged sequentially from bottom to top. The primary leak detection device includes a rotating shaft 5, a detection gate 4, a leak-stopping switch 7, and a counterweight 8. The side arm of the belt chute cover has a square hole located between the drive wheel 17 of belt 1 and the rear tail pulley 20 of belt 2. Two 12mm diameter... Nut 6, two nuts 6 are set in parallel. The rotating shaft 5 is made of 8mm U-shaped threaded steel and passes through the two nuts 6. The rotating shaft 5 is located above the square hole 3. The detection door 4 is hinged to the rotating shaft 5. A leak-stopping switch 7 is fixedly connected to one side of the square hole 3. The leak-stopping switch 7 is used to detect the position signal of the detection door 4. The size of the detection door 4 is larger than the size of the square hole 3. The detection door 4 completely covers the square hole 3. A counterweight 8 is fixed at the bottom of the detection door 4. The detection door 4 is made of 4mm thick iron plate and the counterweight 8 is made of I-beam steel. The leak-stopping switch 7 is a door limit switch, model LX19 warehouse door limit switch, but other models can also be used.

[0050] The secondary leak detection device includes a flap 9, a second rotating shaft 11, an extension tube 12, and a second leak-stopping switch 14. Both sides of the belt conveyor nozzle cover have an opening 10, with the two openings 10 located on the same horizontal plane. The second rotating shaft 11 passes through the opening 10. An iron plate is used as the flap 9 and is fixedly connected to the second rotating shaft 11. Baffles 15 are provided at both ends of the second rotating shaft 11 to prevent it from falling off. The extension tube 12 is located on the outside of the belt conveyor nozzle cover. One end of the extension tube 12 is welded to one end of the second rotating shaft 11, and the other end of the extension tube 12 is connected to one end of a steel wire rope 13. The other end of the steel wire rope 13 is connected to the second leak-stopping switch 14, which is fixedly connected to the foundation of the first belt. The second leak-stopping switch 14 is a belt misalignment switch.

[0051] See Figure 5 , Figure 6The control unit includes a Siemens S7-400 PLC, which includes a CPU module, a digital input module, and a digital output module. The digital input module is connected to the leak-stopping switch 7 and the leak-stopping switch 14 via ports. The digital output module outputs control circuits for the belt conveyor.

[0052] A method for controlling belt conveyor blockage includes:

[0053] S1. When there is no ore collection inside the belt conveyor chute, see Figure 1 , Figure 3 :

[0054] Level 1 Leak Detection Device:

[0055] The detection door 4 closes under the action of the counterweight 8, and does not contact the leak-stopping switch 7. Therefore, the normally closed contact of the leak-stopping switch 7 closes. Figure 6 The normally closed contact DL1 in the middle is closed;

[0056] Two-stage leak detection device:

[0057] Flip plate 9 is vertical, pivot 11 is not rotating, extension tube 12 is vertical, steel wire rope 13 is not taut, and the normally closed contact of leak-stopping switch 14 is closed. Figure 6 The normally closed contact DL2 in the middle is closed;

[0058] S2. When there is ore accumulation inside the conveyor belt chute, see Figure 2 , Figure 4 :

[0059] When large pieces or foreign objects in the ore cause blockage of the conveyor belt's chute, the minerals will accumulate from the bottom upwards. When the accumulated ore height exceeds the detection gate 4 of the primary leak-proof detection device, the ore's squeezing action causes the detection gate 4 to open outwards via the rotating shaft 5, which in turn rotates the shaft of the leak-proof switch 7. Figure 6 When the normally closed contact of DL1 in the middle is opened, the CPU receives the information that the normally closed contact of the leak-stopping switch 7 is open and sends a command to stop the belt.

[0060] If the primary leak detection device fails to detect ore accumulation, the ore accumulation inside the conveyor chute rises. When the ore accumulation touches the flap 9 of the secondary leak detection device, the flap 9 flips over, causing the second shaft 11 to rotate. This rotates the extension pipe 12, tightens the steel wire rope 13, and causes the second leak-stopping switch 14 to rotate, opening its normally closed contact. Figure 6 When the normally closed contact of DL2 in the middle is opened, the CPU receives the information that the normally closed contact of the leak-stopping switch 14 is open and sends a command to stop belt 1.

[0061] Example 2

[0062] In this embodiment, the belt conveyor blockage control system and method are the same as in Embodiment 1, except that a belt conveyor blockage control process is added. (See...) Figure 7 .

[0063] The large-scale process in the ore dressing plant uses a Siemens S7-400 PLC as the main control PLC, with over 5000 input / output points and over 800 backup points. The main control PLC is used for filtering, processing, and interlocking control of the blockage signal. The blockage signal is connected to the backup channel of the main control PLC, such as... Figure 6 In line -71, when the primary and secondary leak detection devices are not activated, DC24V+ is sent to the digital input module after being connected in series through the normally closed contacts DL1 and DL2. The line number is -65, and the corresponding address of the main control PLC is 1. The signal in the main control PLC is processed with reverse logic, so the leak signal is false and no leak occurs.

[0064] When the belt conveyor nozzle becomes clogged, the primary leak detection device will activate, such as... Figure 6 When the normally closed contact DL1 in the circuit opens, the DC24V+ of wire 65 disappears, and the blockage signal sampled by the main control PLC is true. If the secondary leak detection device activates, such as Figure 6 When the normally closed contact DL2 in the PLC is open, the blockage signal sampled by the main control PLC is also true.

[0065] In actual production, blockage detection devices often malfunction due to ore impact. If the blockage signal directly triggers the belt interlock to stop the conveyor belt, it causes unnecessary downtime and reduces production efficiency. These malfunctions share a common characteristic: they are short-lived. Because both the blockage switches DL1 and DL2 have feedback characteristics, the blockage signal caused by this malfunction disappears within 1.2 seconds. A 1.5-second delay filter is used to remove the malfunction signal.

[0066] If the blockage detection device's activation signal remains true for more than 1.5 seconds, it is considered that a real blockage has occurred. The device immediately interlocks and stops the conveyor belt, simultaneously shutting down all upstream conveyor belts and feeding devices for a protective shutdown. Figure 6 As shown, the PLC digital outputs K1 and K2 are disconnected.

[0067] See Figure 6 Part X is the main circuit of the control unit, which supplies power to the drive motor of the belt conveyor. When contactor KM is turned on, the motor of belt one rotates, and belt conveyor 1 runs. Figure 6 The Y section in the diagram represents the control circuit.

[0068] See Figure 6In section Y, when the pull rope and belt misalignment are in normal condition, KA4 and KA2 are closed. If there is no blockage, the main control PLC output K2 closes, energizing the intermediate relay KA3, and its contacts close. When the selector switch SA is turned to the local position, pressing the start button SF on the control box energizes the KA11 start relay. Pressing the stop button SS de-energizes the KA11 start relay. When the selector switch SA is turned to the remote position, the remote allow relay KA1 is energized, and its auxiliary contacts close. Pressing the belt start button on the SCADA interface in the control room triggers a PLC logic operation, closing the K1 contact and energizing the KA11 start relay. Pressing the stop button on the SCADA interface in the control room triggers a PLC logic operation, opening the K1 contact and de-energizing the KA11 start relay.

[0069] See Figure 6 In section Y, after the starting relay KA11 is energized, its auxiliary contact connects the time relay KT, and a warning bell rings before the vehicle turns over. After a 20-second warning, the auxiliary contact of KT closes, the contactor KM is energized, the main circuit contactor closes, the motor rotates, and the belt runs.

[0070] When belt conveyor clogging occurs, after PLC signal processing, the output control signal will cause the normally open contact of digital output K1 to open, the normally closed contact of K2 to open, KA11 to be de-energized, KT to be de-energized, KM to be de-energized, the main circuit contactor to be de-energized, and the belt conveyor to stop running. The normally closed contact of K2 to open, KA3 to be de-energized, and the auxiliary contact of KA3 to open, which is used for clogging and shutdown protection during manual control.

[0071] After a belt conveyor clogging occurs, the main control PLC system interlocks and shuts down. Simultaneously, the SCSAD system sends an audible and flashing alert to the operator's computer in the central control center, notifying monitoring personnel to handle the situation. After manually resolving the belt clogging fault, the SCSAD system resets the fault, removes the equipment start-up lockout, and the equipment can resume operation.

[0072] This invention features a two-stage detection system. The first-stage leak detection device is a low-level detection: a detection gate 4 and a counterweight 8 are installed below the belt conveyor nozzle, triggering the detection at the initial stage of blockage to prevent excessive material accumulation. Above the belt conveyor nozzle, a flap 9 and a second leak-stopping switch 14 are installed as redundant protection, ensuring reliable belt stop even if the first-stage leak detection device fails. A 1.5-second delay filtering: short-term interference signals such as ore impact are filtered through PLC logic, triggering belt stop only when the blockage signal lasts longer than 1.5 seconds, significantly reducing the probability of false stops. Mechanical anti-interference structure: a U-shaped threaded steel shaft and counterweight are used, resistant to ore impact and dust adhesion. The flap + rope mechanism has no precision electronic components. This design avoids failures caused by vibration and moisture; compared to microwave / ultrasonic sensors, it has a simpler mechanical structure, requiring only cleaning or replacement of worn parts for maintenance; it provides early warning and low-level priority detection: the primary detection point is located below the belt drive pulley, triggering the system at the initial stage of material blockage, preventing material from accumulating on the belt or top of the chute, stopping not only the faulty belt but also interlocking to stop upstream equipment (such as the feeder) to prevent the blockage from spreading; it provides real-time alarms through the SCADA system, shortening fault handling time; it is compatible with multiple control modes, including local / remote dual modes. Local mode: operated via on-site buttons, suitable for maintenance or debugging; Remote mode: integrated into the SCADA system for centralized monitoring.

Claims

1. A belt conveyor blockage control system, comprising a first belt, a second belt, and a belt chute cover, wherein the first belt is disposed above the second belt, and the second belt is used to receive material from the first belt, characterized in that, It also includes a primary leak detection device and a secondary leak detection device. The belt chute cover is equipped with a primary leak detection device and a secondary leak detection device from bottom to top. The primary leak detection device includes a rotating shaft, a detection door, and a leak-stopping switch. The side arm of the belt chute cover has a square hole, which is located between the drive wheel of belt one and the rear tail pulley of belt two. The rotating shaft is fixed on the outer wall of the belt chute cover and is located above the square hole. The detection door is hinged to the rotating shaft. A leak-stopping switch is fixedly connected to one side of the square hole. The leak-stopping switch is used to detect the position signal of the detection door. The size of the detection door is larger than the size of the square hole. The leak-stopping switch and the primary and secondary leak-stopping detection devices are connected to the control unit.

2. The belt conveyor blockage control system according to claim 1, characterized in that, The secondary leak detection device includes a flap, a second rotating shaft, an extension tube, and a second leak-stopping switch. Both sides of the belt chute cover have an opening. The second rotating shaft passes through the opening. The flap is fixedly connected to the second rotating shaft. One end of the extension tube is fixedly connected to one end of the second rotating shaft. The extension tube is located outside the belt chute cover. The other end of the extension tube is connected to one end of the steel wire rope. The other end of the steel wire rope is connected to the second leak-stopping switch. The second leak-stopping switch is fixedly connected to the foundation of the first belt. Leakage stopper 1 and leakage stopper 2 are connected to the control unit.

3. The belt conveyor blockage control system according to claim 1, characterized in that, The aforementioned primary leak detection device also includes a counterweight, with the lower part of the detection door fixed with a counterweight.

4. The belt conveyor blockage control system according to claim 1, characterized in that, The belt spout cover above the square hole is fixed with two nuts, and the rotating shaft passes through the two nuts, so that the detection door completely covers the square hole.

5. A belt conveyor blockage control system according to claim 1, characterized in that, The aforementioned leak-stopping switch is a door limit switch.

6. A belt conveyor blockage control system according to claim 1, characterized in that, The two ends of the rotating shaft are provided with baffles to prevent the rotating shaft from falling off.

7. A belt conveyor blockage control system according to claim 2, characterized in that, The second leak-stopping switch is a deviation switch.

8. A belt conveyor blockage control system according to claim 1, characterized in that, The control unit includes a PLC, which includes a digital input module. The digital input module is connected to the first leak-stopping switch and the second leak-stopping switch via a port.

9. A belt conveyor blockage control method for implementing the control system according to any one of claims 1-8, characterized in that, include: S1. When there is no ore collection inside the belt conveyor chute: Level 1 Leak Detection Device: The detection door closes under the action of the counterweight, and does not contact the first leak-stopping switch, so the normally closed contact of the first leak-stopping switch closes. Two-stage leak detection device: The flap is vertical, the second rotating shaft is not rotating, the extension tube is vertical, the steel wire rope is not taut, and the normally closed contact of the second leak-stopping switch is closed. S2. When there is ore collected inside the conveyor chute: Minerals will accumulate from the bottom up. When the height of the accumulated minerals exceeds the detection gate of the first-level leak-proof detection device, the detection gate will open outward through the rotating shaft due to the squeezing action of the minerals. The control unit receives the information that the normally closed contact of the leak-proof switch is disconnected and sends a command to stop the belt. If the primary leak detection device does not detect the ore collection information, the ore collection in the belt chute will rise. When the ore collection touches the flap of the secondary leak detection device, the flap will flip, the second shaft will rotate, the extension tube will rotate, the steel wire rope will tighten, and the control unit will receive the information that the normally closed contact of the leak-stopping switch two is open and send a command to stop belt one.

Images