Foreign matter detection and discharge system for head of belt conveyor and signal processing method thereof

Abstract

The present application relates to a kind of foreign matter detection, discharge system and its signal processing method for belt conveyor head.The present application includes head protection cover, belt conveyor head, with coal chute or coal chute, belt conveyor controller, magnetic flux sensing element and cross support bar, to fill the gap in the prior art, opposite vertical sliding groove is opened on the both sides of head protection cover respectively, vertical sliding groove outside side plate is fixed support frame, upper slide block, lower slide block and position sensor are arranged in support frame, between them there is helical support spring, adjusting screw is arranged on the bottom edge of support frame, the upper end of adjusting screw is abutted on lower slide block, upper slide block is respectively sleeved on the outer end of two cross support bars, magnetic flux sensing element is fixed in protection cover, position sensor and magnetic flux sensing element are connected with the signal input end of the PLC of belt conveyor controller respectively by signal line, window is opened on back plate.The present application is simple, reliable, suitable for processing with coal flow movement not out head ferromagnetic foreign matter.

Description

TECHNICAL FIELD

[0001] The present application relates to a foreign matter detection and discharge system for a belt conveyor head and a signal processing method thereof. BACKGROUND

[0002] Long foreign matter is a difficult problem for coal mine raw coal lifting system, which is easy to cause belt tearing production accidents and safety accidents during personnel handling process. In the transportation process of the field belt, long foreign matter is easy to mix in, and at the belt head position, the long foreign matter is easy to be stuck at the head part due to the change of the material running direction, causing the belt damage or falling into the stock bin to block the discharge port.

[0003] A single prop catcher is disclosed in the Chinese Utility Model Patent with the publication number CN 205805592 U published on December 14, 2016. The single prop is easy to be knocked down and lost during the blasting process. The single prop catcher includes a belt conveyor, a belt conveyor drive circuit, a belt conveyor emergency stop switch, a hanging frame, and a high-strength permanent magnet. The hanging frame includes two props and a crossbeam fixed at the top of the props. The two props are fixed on the two sides of the belt conveyor or the frame of the belt conveyor. A longitudinal fixing rod is fixed in the middle of the crossbeam. One end of the longitudinal fixing rod is provided with a pull switch connected to the emergency stop circuit of the belt conveyor. The other end of the longitudinal fixing rod is provided with a pulley. The pull switch is provided with a return spring. The pull rope of the pull switch passes over the pulley and is suspended above the belt conveyor. The high-strength permanent magnet is tied to the end of the pull rope. When the single prop is on the upper belt of the belt conveyor, the high-strength permanent magnet attracts the prop, drives the pull switch, and starts the emergency stop program of the belt conveyor. When the single prop is detected in the coal flow, the belt conveyor emergency stop program is automatically started, and the staff is waiting for processing, but the single prop or other anchors, anchor cables, steel belts, and other ironware in the coal flow cannot be automatically removed.

[0004] A belt conveyor preventing foreign matter from extending outward is disclosed in the Chinese Utility Model Patent with the publication number CN 215796383 U published on February 11, 2022. The belt conveyor includes a rod limiting rod and a roll and pull roller set on the tail frame of the belt conveyor. The rod limiting rod includes a base connected to the tail frame and a vertical rod fixed on the base. The roll and pull roller set includes a roller frame and upper and lower rollers arranged on the roller frame. The roller frame is installed on the tail frame. The rotation shaft of the roller is parallel to the belt conveying direction. The roller is covered with a rubber roller skin. The roller includes a cylindrical body and an integrally connected conical tip. The tip points to the belt inflow direction. The bodies of the upper and lower rollers are close together. The upper and lower rollers are connected to a torque input element.

[0005] Hard rod such as anchor rod on the belt conveyor is blocked and collided by the rod limiting rod, and the anchor rod will be retracted into the belt obediently. For the foreign matter such as anchor cable and steel belt, since it has a certain elasticity, it will be folded back when touching the rod limiting rod, and will be bounced out immediately after passing through the rod limiting rod. For such elastic foreign matter, a winding and pulling roller group is arranged on the tail frame, and the foreign matter such as anchor cable and steel belt exceeding the length enters between the upper and lower rollers of the winding and pulling roller group, and moves along with the belt, while the two rollers also rotate to apply force, so as to drag the anchor cable and steel belt out of the coal pile, and the dropped anchor cable and steel belt are collected in the falling collection groove.

[0006] The patent pursues "iron does not protrude, and safety is not worried", and only the iron foreign matter of the belt conveyor does not protrude, so that the target of "iron does not protrude, and safety is not worried" is achieved. However, some iron foreign matters do not protrude when falling on the upper belt of the belt conveyor, and the patent technology will pass them without any treatment. However, these iron foreign matters which do not protrude on the upper belt of the belt conveyor will fall into the coal chute or coal chute after passing through the head of the belt conveyor, and will form blockage in the coal chute or coal chute, which affects the coal chute, and the long anchor rod end may be arranged on the head of the belt conveyor, which may cause damage to the belt conveyor.

[0007] The prior art lacks a system and technology which can detect the non-protruding ferromagnetic foreign matter moving with the coal flow on the belt conveyor, and can automatically discharge most or part of the ferromagnetic foreign matter, and can also timely issue an alarm and urgently stop the belt conveyor and the associated transfer machine for the ferromagnetic foreign matter which cannot be discharged. SUMMARY

[0008] The technical problem to be solved by the present application is how to fill the gap in the prior art, and to provide a foreign matter detection and discharge system for the head of a belt conveyor and a signal processing method thereof, which can detect the non-protruding ferromagnetic foreign matter moving with the coal flow on the belt conveyor, and can automatically discharge most or part of the ferromagnetic foreign matter, and can also timely issue an alarm and urgently stop the belt conveyor and the associated transfer machine for the ferromagnetic foreign matter which cannot be discharged.

[0009] To solve the above technical problems, the foreign matter detection and discharge system for the head of the belt conveyor comprises a head protection cover, a belt conveyor head, a coal chute or a coal chute for use, and a belt conveyor controller, the coal chute or the coal chute for use is located below the coal flow falling point of the belt conveyor head, the head protection cover comprises a top plate, a back plate, and two side plates, the two side plates are respectively located on the two sides of the belt conveyor head, the two side edges of the top plate are respectively connected with the upper edges of the two side plates, the upper edge of the back plate is connected with the rear edge of the top plate, and the two side edges of the back plate are respectively connected with the rear edges of the two side plates, the belt conveyor controller comprises a PLC, and is characterized in that the belt conveyor controller further comprises a magnetic flux sensing element and a horizontal supporting rod, opposite vertical sliding grooves are formed in the two side plates of the head protection cover, a supporting frame is fixed on the side plates around the vertical sliding grooves, an upper sliding block and a lower sliding block are arranged in the supporting frame and can slide up and down in the supporting frame, a helical supporting spring is arranged between the upper sliding block and the lower sliding block, a position sensor for sensing the position of the upper sliding block is arranged on the top of the supporting frame, a vertical threaded hole is formed in the bottom edge of the supporting frame, an adjusting screw is rotatably arranged in the vertical threaded hole, the upper end of the adjusting screw abuts against the lower sliding block, a through hole is formed in the upper sliding block and the horizontal supporting rod is sleeved with the same side end of the upper sliding block through the through hole, the upper sliding block is arranged in the vertical sliding groove, the magnetic flux sensing element is fixed below the top plate of the head protection cover, the position sensor and the magnetic flux sensing element are respectively connected with the signal input end of the PLC of the belt conveyor controller through signal lines, and the back plate is provided with a window.

[0010] When a ferromagnetic foreign matter (iron or magnet) passes through, the magnetic flux sensing element can sense the change of the magnetic flux. When a heavy object presses on the horizontal supporting rod, the upper sliding block is pressed to descend, which can also be sensed by the position sensor.

[0011] The PLC comprehensively judges whether the head protection cover is blocked by a foreign matter, whether the foreign matter is a ferromagnetic metal object, a wooden stick, a large piece of gangue, or other foreign matters, and processes the foreign matter according to different situations.

[0012] The magnetic flux sensing element refers to the magnetic flux sensing coil in CN 105629313 B, and the belt conveyor controller refers to CN 212100722 U. The position sensor can be an infrared position sensor or other existing position sensors. Such a design is simple in structure and reliable in operation.

[0013] As an optimization, the window is provided with a curtain or a movable door, the upper edge of the curtain or the movable door is hinged to the upper edge of the window, and the curtain or the movable door can be lifted outward. Such a design can reduce the dust in the coal flow escaping from the head protection cover.

[0014] As optimization, the cross support rod is also sleeved with a roller. In this way, the foreign matter in the front paragraph is sleeved on the roller and moves forward, the roller rotates with it, changes the sliding friction into rolling friction, and the resistance is small.

[0015] The signal processing method of the foreign matter detection and discharge system for the head of the belt conveyor is as follows: the PLC receives the signal sent by the magnetic flux sensing element and processes as follows:

[0016] When the PLC finds that the magnetic flux detection signal changes instantaneously (the total change time is not more than 0.36 seconds, which is manifested as a sharp peak signal), and the upper slider position sensing signal does not change during this process, it is judged that a small ferromagnetic foreign matter (such as a screw or a nut) passes with the coal flow and falls into the coal chute or coal chute, and the PLC controls the belt conveyor controller to only count the small ferromagnetic foreign matter, which is processed by the downstream magnetic separation process or coal washing process.

[0017] When the PLC finds that the magnetic flux detection signal changes and returns to normal within 3 seconds, and the upper slider position sensing signal does not change during this process, it is judged that a medium-length ferromagnetic foreign matter (length not more than 1.2 meters) passes and has been discharged through the window, the PLC controls the belt conveyor controller to issue an alarm or count, and notifies the staff to collect the medium-length ferromagnetic foreign matter at the window.

[0018] When the PLC finds that the magnetic flux detection signal changes and does not return to normal within 3 seconds, and the PLC finds that the upper slider position is lowered through the position sensor, it is judged that a long ferromagnetic foreign matter (length more than 1.2 meters) or a special-shaped ferromagnetic foreign matter passes, but cannot be discharged through the window, and the long ferromagnetic foreign matter or the special-shaped ferromagnetic foreign matter is partially pressed on the cross support rod, the PLC controls the belt conveyor controller to issue a belt conveyor emergency stop signal and a transfer machine emergency stop signal, and performs emergency stop processing on the belt conveyor and the matched transfer machine, and issues an alarm to notify the staff to handle.

[0019] When the PLC finds that the magnetic flux detection signal does not change, but the PLC finds that the upper slider position is lowered through the position sensor, and cannot be restored within 3 seconds, it is judged that a non-ferromagnetic foreign matter (wooden stick, large gangue or other non-ferromagnetic foreign matter) is partially pressed on the cross support rod, the PLC controls the belt conveyor controller to issue a belt conveyor emergency stop signal and a transfer machine emergency stop signal, and performs emergency stop processing on the belt conveyor and the matched transfer machine, and issues an alarm to notify the staff to handle.

[0020] In this way, through the simple position sensor and magnetic flux sensing element, the PLC can automatically judge the nature of the foreign matter coming with the coal flow, and make different treatments.

[0021] The foreign matter detection and discharge system for the head of the belt conveyor and the signal processing method thereof have simple structure, reliable operation, and are suitable for processing non-ferromagnetic foreign matters moving with the coal flow on the belt conveyor. Attached Figure Description

[0022] The foreign object detection and removal system for the head of a belt conveyor and its signal processing method according to the present invention will be further described below with reference to the accompanying drawings:

[0023] Figure 1 This is a side view of the foreign object detection and removal system at the head of the belt conveyor.

[0024] Figure 2 yes Figure 1 Schematic diagram of the cross-sectional structure of the A-A belt (omitting the coal chute and the head frame of the belt conveyor).

[0025] In the diagram: 1 is the head cover, 11 is the top plate, 12 is the back plate, 13 is the side plate, 14 is the vertical chute, 2 is the head of the belt conveyor, 3 is the coal chute, 4 is the magnetic flux sensing element, 5 is the horizontal support rod, 6 is the support frame, 7 is the upper slider, 8 is the lower slider, 9 is the spiral support spring, 10 is the adjusting screw, 15 is the window, 16 is the movable door, 17 is the roller, 18 is the long ferromagnetic foreign object, 19 is the short column, and 20 is the position sensor. Detailed Implementation

[0026] Implementation method one: such as Figures 1-2 As shown, the foreign object detection and discharge system for the head of this belt conveyor includes a head protection cover 1, a belt conveyor head 2, a coal chute 3 (or coal chute, omitted), and a belt conveyor controller (not shown in the figure). The coal chute 3 is located below the coal drop point of the belt conveyor head 2. The head protection cover 1 includes a top plate 11, a back plate 12, and two side plates 13. The two side plates 13 are located on both sides of the belt conveyor head 2. The two sides of the top plate 11 are connected to the upper sides of the two side plates 13, the upper side of the back plate 12 is connected to the rear side of the top plate 11, and the two sides of the back plate 12 are connected to the rear sides of the two side plates 13. The belt conveyor controller includes a PLC (not shown in the figure).

[0027] Its characterized in that: it still includes magnetic flux induction element 4 and cross support pole 5, the both sides board 13 of head protection cover 1 is opened with opposite vertical sliding slot 14 respectively, and the side board of vertical sliding slot 14 periphery is fixed with a support frame 6, the support frame 6 is equipped with upper sliding block 7 and lower sliding block 8, both can slide in the support frame 6, and is equipped with helical support spring 9 between both, the support frame 6 top is equipped with position sensor 20 for sensing the position of upper sliding block 7, the vertical screw hole is opened in the bottom edge of support frame 6, the adjusting screw 10 is rotated in the vertical screw hole, the upper end of adjusting screw 10 is resisted on lower sliding block 8, the upper sliding block 7 is opened with through hole, and is set on the same side end of cross support pole 5 through the through hole, the magnetic flux induction element 4 is fixed below the top plate 11 of head protection cover 1, position sensor 20 and magnetic flux induction element 4 are connected with the signal input end of PLC of belt conveyor controller respectively through signal line, the window 15 is opened in back plate 12, and position sensor 20 and magnetic flux induction element 4 respectively send the position sensing signal and magnetic flux detection signal of upper sliding block 7 to PLC in real time.

[0028] As shown in Figure 2 The part of upper sliding block 7 is embedded in vertical sliding slot 14, and can move up and down in vertical sliding slot 14, and the other part of upper sliding block 7 is located in support frame 6, and can move up and down in support frame 6. Upper sliding block 7 and lower sliding block 8 are respectively provided with opposite short columns 19, and the helical support spring 9 is respectively sleeved in short column 19, which can effectively prevent helical support spring 9 from separating from upper sliding block 7 and lower sliding block 8.

[0029] The window 15 is provided with a hanging curtain or a movable door 16, the upper edge of the hanging curtain or the movable door 16 is hinged to the window 15 along the upper edge and can be lifted outward. The cross support pole 5 is also sleeved with a roller 17.

[0030] The two ends of the cross support pole 5 are elastically supported by the helical support springs 9. When a long ferromagnetic foreign matter 18 presses on the cross support pole 5 and fails to be completely discharged from the window, and is stuck in the cross support pole 5, the long ferromagnetic foreign matter 18 can be taken out by appropriately lowering the cross support pole 5. The upper edge of the roller 17 on the cross support pole 5 should be lower than the height of the upper belt of the head 2 of the belt conveyor, and the height of the cross support pole 5 can be adjusted by the adjusting screw 10.

[0031] The signal processing method of the foreign matter detection and discharge system for the head of the belt conveyor, the PLC receives the signal sent by the magnetic flux induction element 4, and processes as follows:

[0032] When the PLC finds that the magnetic flux detection signal changes instantaneously (the total change time is not more than 0.36 seconds, which is manifested as a sharp peak signal), and the position sensing signal of the upper slider 7 does not change during this process, it is determined that small ferromagnetic foreign matter (such as screws, nuts) passes with the coal flow and falls into the matching coal chute 3 along with the coal flow. The PLC control of the belt conveyor controller only counts, and the small ferromagnetic foreign matter is treated by the downstream magnetic separation process or the coal washing process;

[0033] When the PLC finds that the magnetic flux detection signal changes and returns to normal within 3 seconds, and the position sensing signal of the upper slider 7 does not change during this process, it is determined that a medium-length ferromagnetic foreign matter (length not more than 1.2 meters) passes and has been discharged through the window 15. The PLC control of the belt conveyor controller issues an alarm or count to notify the staff to collect the medium-length ferromagnetic foreign matter at the window 15;

[0034] When the PLC finds that the magnetic flux detection signal changes and does not return to normal within 3 seconds, and the PLC finds that the position of the upper slider 7 is lowered through the position sensor 20, it is determined that a long ferromagnetic foreign matter 18 (length more than 1.2 meters) or a special-shaped ferromagnetic foreign matter passes, but cannot be discharged through the window 15, and the long ferromagnetic foreign matter 18 or the special-shaped ferromagnetic foreign matter is partially pressed on the horizontal support rod 5. The PLC control of the belt conveyor controller issues a belt conveyor emergency stop signal and a transfer machine emergency stop signal to stop the belt conveyor and the matching transfer machine, and issues an alarm to notify the staff to handle;

[0035] When the PLC finds that the magnetic flux detection signal does not change, but the PLC finds that the position of the upper slider 7 is lowered through the position sensor 20, and cannot be restored within 3 seconds, it is determined that a non-ferromagnetic foreign matter (not shown in the figure) is partially pressed on the horizontal support rod 5. The PLC control of the belt conveyor controller issues a belt conveyor emergency stop signal and a transfer machine emergency stop signal to stop the belt conveyor and the matching transfer machine, and issues an alarm to notify the staff to handle.

Claims

1. A foreign matter detection and discharge method for a belt conveyor head, comprising a head protection cover, a belt conveyor head, a matched coal chute or coal chute and a belt conveyor controller, the matched coal chute or coal chute is located below the coal flow falling point of the belt conveyor head, the head protection cover comprises a top plate, a back plate and two side plates, the two side plates are respectively located on both sides of the belt conveyor head, the two side edges of the top plate are respectively connected with the upper edges of the two side plates, the upper edge of the back plate is connected with the rear edge of the top plate, and the two side edges of the back plate are respectively connected with the rear edges of the two side plates, the belt conveyor controller comprises a PLC, characterized in that: It also includes magnetic flux sensing element and cross support rod, the two side plates of the head protection cover are respectively provided with opposite vertical sliding grooves, a support frame is fixed on the side plate around the vertical sliding groove, the support frame is provided with an upper sliding block and a lower sliding block which can slide up and down in the support frame, and a spiral supporting spring is arranged between the two, the support frame top is provided with a position sensor for sensing the position of the upper sliding block, a vertical threaded hole is formed in the bottom edge of the support frame, and an adjusting screw is rotatably arranged in the vertical threaded hole, the upper end of the adjusting screw abuts against the lower sliding block, a through hole is formed in the upper sliding block and the same side end of the cross support rod is sleeved on the through hole, the upper sliding block is arranged in the vertical sliding groove, the magnetic flux sensing element is fixed below the top plate of the head protection cover, the position sensor and the magnetic flux sensing element are respectively connected with the signal input end of the PLC of the belt conveyor controller through signal lines, the back plate is provided with a window, the position sensor and the magnetic flux sensing element respectively send the upper sliding block position sensing signal and the magnetic flux detection signal to the PLC in real time, and the PLC receives the signal sent by the magnetic flux sensing element and processes as follows: When the PLC finds that the magnetic flux detection signal changes instantaneously and the upper sliding block position sensing signal does not change in the process, it is judged that small ferromagnetic foreign matters pass along with the coal flow and fall into the coal chute or the coal chute, and the PLC controls the belt conveyor controller to only count, and the small ferromagnetic foreign matters are treated by the downstream magnetic separation process or the coal washing process; When the PLC finds that the magnetic flux detection signal changes and returns to normal within 3 seconds, and the upper sliding block position sensing signal does not change in the process, it is judged that a medium-length ferromagnetic foreign matter passes and has been discharged through the window, the PLC controls the belt conveyor controller to issue an alarm or count, and notifies the staff to collect the medium-length ferromagnetic foreign matter at the window; When the PLC finds that the magnetic flux detection signal changes and does not return to normal within 3 seconds, and the PLC finds that the position of the upper sliding block is lowered through the position sensor, it is judged that a long ferromagnetic foreign matter or a special-shaped ferromagnetic foreign matter passes, but cannot be discharged through the window, and the long ferromagnetic foreign matter or the special-shaped ferromagnetic foreign matter is partially pressed on the cross support rod, the PLC controls the belt conveyor controller to issue a belt conveyor emergency stop signal and a matching transfer machine emergency stop signal, and the belt conveyor and the matching transfer machine are stopped, and an alarm is issued to notify the staff to handle; When the PLC finds that the magnetic flux detection signal does not change, but the position of the upper sliding block is lowered through the position sensor and cannot be restored within 3 seconds, it is judged that a non-ferromagnetic foreign matter is partially pressed on the cross support rod, the PLC controls the belt conveyor controller to issue a belt conveyor emergency stop signal and a matching transfer machine emergency stop signal, and the belt conveyor and the matching transfer machine are stopped, and an alarm is issued to notify the staff to handle.

2. The foreign matter detecting and discharging method for the head of a belt conveyor according to claim 1, characterized by: The window is provided with a hanging curtain or a movable door, and the upper edge of the hanging curtain or the movable door is hinged to the upper edge of the window and can be lifted outward.

3. The foreign matter detecting and discharging method for the head of a belt conveyor according to claim 1, characterized by: The cross support rod is further sleeved with a roller.

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