Device and method for cleaning accumulated coal below rack of belt conveyor

Abstract

The invention relates to a device and method for cleaning accumulated coal below a rack of a belt conveyor, the device comprises a first gear and a second gear which are oppositely arranged, the first gear is located on the outer side of the rack below a pressing roller, and the second gear is located on the inner side of the rack and connected with the outer wall face of a coal falling pipe. A chain is in transmission connection between the first gear and the second gear, a scraper blade and a photoelectric reflection sensor are mounted on the chain, and the photoelectric reflection sensor is in communication connection with the controller and used for collecting distance signals between the photoelectric reflection sensor and the surface of the coal pile and transmitting the distance signals to the controller; the controller is connected with the driving motor, the first gear is connected with an output shaft of the driving motor, and the controller is used for calculating the height of the coal pile and correspondingly controlling the working state of the driving motor. Compared with the prior art, accumulated coal below the rack of the belt conveyor can be automatically, conveniently and effectively cleaned, so that stable and reliable operation of the belt conveyor is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of power plant conveying equipment, and in particular to a device and method for cleaning coal accumulation under the frame of a belt conveyor. Background Art

[0002] In the fuel system of a coal-fired power plant, a belt conveyor is usually used to convey coal, and its main structure is as Figure 1 shown, including a belt, a head roller, a tensioning roller, a frame, and a coal dropping pipe. Among them, the belt bypasses the head roller and the tensioning roller in sequence. The head roller is located at the opening position of the coal dropping pipe, and the coal carried on the belt is discharged and collected into the coal dropping pipe through the driving belt. The tensioning roller is inclinedly installed on the frame and is used to drive the belt after conveying the coal to the initial position.

[0003] In the prior art, considering that coal fragments are likely to adhere to the belt for carrying coal, which is likely to cause wear to the belt itself and the rollers, a cleaning device is usually provided at the position of the head roller. However, in actual application, due to limited cleaning effect, the coal adhered to the surface of the belt cannot be effectively cleaned and fallen into the coal dropping pipe. With the operation of the belt, coal accumulation often occurs under the belt conveyor. When the coal accumulation is serious, it will inevitably cause the tensioning roller to be stuck and not rotate, resulting in an operation risk of the belt conveyor. In order to avoid the influence of coal accumulation on the normal and stable operation of the belt conveyor, the traditional method is to organize personnel to carry out cleaning work after the production task is completed, which is undoubtedly time-consuming and laborious. Moreover, due to the existence of the tensioning roller, the manual cleaning work is relatively difficult.

[0004] Some studies have designed to further clean the return belt passing through the tensioning roller. For example, Chinese Patent CN207312514U proposes a cleaning device for the coal-carrying surface of a belt conveyor, which sets a cleaning frame along the belt direction, closely fits with the bottom of the return belt of the belt conveyor through a spring bracket, and peels off the coal fragments on the surface of the return belt through the cleaning plate on the cleaning frame. However, due to the complex steel structure under the head of the belt conveyor, the installation space of this cleaning device is limited (it can only be installed on one side of the tensioning roller), so this cleaning device can only solve part of the coal accumulation problem and is powerless for the coal accumulation between the frame below, that is, between the tensioning roller and the coal dropping pipe. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art and provide a device and method for cleaning coal accumulation under the frame of a belt conveyor, which can automatically, conveniently and effectively clean the coal accumulation under the frame of the belt conveyor, so as to ensure the stable and reliable operation of the belt conveyor.

[0006] The object of the present invention can be achieved by the following technical solutions: A device for cleaning accumulated coal under the frame of a belt conveyor, including a first gear and a second gear arranged oppositely. The first gear is located outside the frame below the pressing roller, and the second gear is located inside the frame and connected to the outer wall surface of the coal dropping pipe. A chain is drivingly connected between the first gear and the second gear, and a scraper and a photoelectric reflection sensor are installed on the chain. The photoelectric reflection sensor is communicatively connected to a controller, and is used for collecting the distance signal between the photoelectric reflection sensor and the surface of the coal pile and transmitting it to the controller;

[0007] The controller is connected to a driving motor, the first gear is connected to the output shaft of the driving motor, and the controller is used for calculating the height of the coal pile and correspondingly controlling the working state of the driving motor.

[0008] Further, the driving motor and the first gear are installed on a fixing seat, and the bottom of the fixing seat is connected to the coal accumulation platform.

[0009] Further, a connecting shaft is provided on the outer wall surface of the coal dropping pipe, and the second gear is sleeved on the connecting shaft.

[0010] Further, the connecting shaft and the output shaft of the driving motor are at the same horizontal height.

[0011] Further, an opening is formed on the outer wall surface of the coal dropping pipe, and the opening communicates with the end of the coal accumulation platform.

[0012] Further, the driving direction of the chain is from the outside of the frame to the inside of the frame.

[0013] Further, a tension adjuster is installed at the position of the first gear for adjusting the tension of the chain.

[0014] A method for cleaning accumulated coal under the frame of a belt conveyor includes the following steps:

[0015] S1. The photoelectric reflection sensor collects the distance signal between itself and the surface of the coal pile and transmits it to the controller;

[0016] S2. The controller correspondingly calculates the current height of the coal pile. If the current height of the coal pile is greater than or equal to a preset threshold, step S3 is executed; otherwise, return to step S1;

[0017] S3. The controller outputs a signal to control the driving motor to start rotating, correspondingly driving the first gear to drive the second gear to rotate, and synchronously driving the chain, so that the scraper moves from the outside of the frame to the inside of the frame and sweeps the accumulated coal;

[0018] During this process, the photoelectric reflective sensor collects the distance signal between itself and the surface of the coal pile in real time, and the controller updates and calculates the current coal pile height in real time. If the current coal pile height is less than the preset threshold, the output signal controls the drive motor to stop rotating, and then returns to step S1.

[0019] Furthermore, in step S1, the photoelectric reflection sensor collects the distance signal between itself and the surface of the coal pile as follows:

[0020]

[0021] Where D is the distance between the photoelectric reflective sensor and the surface of the coal pile, f is the focal length of the lens, b is the transmitting and receiving distance, and θ is the divergence angle of the transmitting light beam.

[0022] Furthermore, the controller calculates the current coal pile height using the formula:

[0023] h=H0-D·cos(α)

[0024] Wherein, h is the height of the coal pile, H0 is the installation reference height of the photoelectric reflection sensor, and α is the inclination compensation coefficient of the photoelectric reflection sensor.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] The present invention provides a first gear on the outside of the frame below the compacting roller, and a second gear on the inside of the frame. The second gear is connected to the outer wall of the coal drop pipe. A chain is connected between the first and second gears, and a scraper and a photoelectric reflection sensor are installed on the chain. The photoelectric reflection sensor collects the distance signal between itself and the surface of the coal pile and transmits it to the controller. The controller calculates the height of the coal pile and controls the working state of the drive motor accordingly, thereby driving the first and second gears to rotate in sequence. The synchronous chain transmission enables the scraper to move from the outside of the frame to the inside of the frame for cleaning. In this way, the accumulated coal under the belt conveyor frame can be automatically, conveniently and effectively cleaned, thereby improving the operational stability of the belt conveyor.

[0027] The present invention provides a connecting shaft on the outer wall of the coal drop pipe, and sleeves the second gear on the connecting shaft. On the one hand, it can make full use of the installation space, and on the other hand, it can ensure that the scraper can effectively clean the accumulated coal between the inner side of the frame and the coal drop pipe below the frame.

[0028] The present invention has an opening on the outer wall of the coal drop pipe, and the opening is connected to the end of the coal accumulation platform under the frame, so that the coal fragments swept from the outside of the frame to the inside of the frame by the scraper can be directly collected into the coal drop pipe.

[0029] The present invention calculates the height of the coal pile by using the controller in combination with the inclination compensation coefficient of the photoelectric reflection sensor, which can ensure the accuracy of the detection of the coal pile height, is beneficial to timely and accurately controlling the working state of the driving motor subsequently. At the same time, during the scraper cleaning process, the photoelectric reflection sensor continuously collects the distance signal between itself and the surface of the coal pile in real time, and the controller updates and calculates the current coal pile height in real time. Once the coal pile height is less than the preset threshold, a signal is output to control the driving motor to stop rotating, which can improve the energy-saving reliability of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of an existing belt conveyor;

[0031] Figure 2 is a schematic diagram of a belt conveyor equipped with the device of the present invention;

[0032] Figure 3 is a schematic diagram of the working method process of the device of the present invention;

[0033] Description of the marks in the figure: 101, belt; 102, head roller; 103, pressing roller; 104, frame; 105, coal dropping pipe; 201, first gear; 202, second gear; 203, chain; 204, photoelectric reflection sensor; 205, scraper; 206, coal accumulation platform; 207, tension adjuster. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Embodiment 1

[0036] As Figure 2 shown, a device for cleaning coal accumulation under the frame of a belt conveyor is installed on the belt conveyor, and includes a first gear 201 and a second gear 202 which are oppositely arranged. The first gear 201 is located outside the frame 104 below the pressing roller 103, and the second gear 202 is located inside the frame and is connected to the outer wall surface of the coal dropping pipe 105. A chain 203 is drivingly connected between the first gear 201 and the second gear 202, and a scraper 205 and a photoelectric reflection sensor 204 are installed on the chain 203.

[0037] Among them, the photoelectric reflection sensor 204 is communicatively connected to the controller, and is used for collecting the distance signal between the photoelectric reflection sensor 204 and the surface of the coal pile and transmitting it to the controller;

[0038] The controller is connected to the driving motor, the first gear 201 is connected to the output shaft of the driving motor, and the controller is used for calculating the height of the coal pile and correspondingly controlling the working state of the driving motor.

[0039] When the driving motor starts to rotate, the first gear 201 rotates as the driving wheel and the second gear 202 rotates as the driven wheel in sequence (in the counterclockwise direction shown in the figure), synchronously driving the chain 203 to move from the outside of the frame to the inside of the frame. At this time, the scraper 205 on the chain 203 sweeps the coal fragments along the moving direction.

[0040] It should be noted that in practical applications, multiple optoelectronic reflection sensors 204 can be set, and they are not limited to being installed on the chain 203, but can also be installed at corresponding positions below the frame.

[0041] Similarly, the number of scrapers 205 can also be set to multiple.

[0042] In this embodiment, the driving motor and the first gear 201 are installed on a fixed seat, and the bottom of the fixed seat is connected to the coal accumulation platform 206. In this embodiment, a connecting shaft is provided on the outer wall surface of the coal dropping pipe 105, and the second gear 202 is sleeved on the connecting shaft. The connecting shaft and the output shaft of the driving motor are at the same horizontal height. This can further make full use of the existing installation space and ensure that the moving cleaning range of the scraper 205 can fully cover the area from the inside of the frame to the coal dropping pipe.

[0043] In this embodiment, an opening is provided on the outer wall surface of the coal dropping pipe 105, and the opening is communicated with the end of the coal accumulation platform 206, so that the coal fragments swept by the scraper 205 can be directly collected and fall into the coal dropping pipe 105.

[0044] In addition, in this embodiment, a tension adjuster 207 is installed at the position of the first gear 201 to adjust the tension of the chain 203, so as to ensure that the chain 203 has an appropriate tension during the transmission process, prevent the chain from loosening and falling off, and reduce the wear of the gears and the chain.

[0045] Embodiment Two

[0046] Applying the device described in Embodiment One, this embodiment realizes a method for cleaning the coal accumulation under the frame of a belt conveyor, as Figure 3 shown, including the following steps:

[0047] S1. The optoelectronic reflection sensor collects the distance signal between itself and the surface of the coal pile and transmits it to the controller;

[0048] S2. The controller correspondingly calculates the current height of the coal pile. If the current height of the coal pile is greater than or equal to the preset threshold, step S3 is executed; otherwise, return to step S1;

[0049] S3. The controller outputs a signal to control the driving motor to start rotating, and correspondingly drives the first gear to drive the second gear to rotate. Through synchronous chain transmission, the scraper moves from the outside of the frame to the inside of the frame and sweeps the accumulated coal;

[0050] During this process, the optoelectronic reflection sensor real-time collects the distance signal between itself and the coal pile surface, and the controller real-time updates and calculates the current coal pile height. If the current coal pile height is less than the preset threshold, it outputs a signal to control the driving motor to stop rotating, and then returns to step S1.

[0051] Among them, the transmitting end of the optoelectronic reflection sensor emits modulated infrared light (wavelength 850 - 940nm). After being diffusely reflected by the coal pile surface, the receiving end detects the reflected light intensity through an avalanche photodiode (APD). According to the Lambert-Beer law, the reflected light intensity is inversely proportional to the square of the distance. Combining the triangulation method, the distance from the sensor to the coal pile surface is calculated as:

[0052]

[0053] In the formula, D is the distance between the optoelectronic reflection sensor and the coal pile surface, f is the lens focal length, b is the transmitting and receiving spacing, and θ is the divergence angle of the transmitting beam;

[0054] The formula for the controller to calculate the current coal pile height is:

[0055] h = H0 - D·cos(Δ)

[0056] In the formula, h is the coal pile height, H0 is the installation reference height of the optoelectronic reflection sensor, and α is the inclination compensation coefficient of the optoelectronic reflection sensor.

[0057] If multiple optoelectronic reflection sensors are installed in practical applications, then the D-S evidence theory can be used to fuse the multi-sensor data to construct the contour map of the coal pile surface and realize the fusion calculation of the thickness of the coal accumulation area.

[0058] In addition, when actually installing and arranging the optoelectronic reflection sensors, the sensor type can be selected according to different on-site scenarios. For example, for a small coal yard, the OPB704 type of optoelectronic reflection sensor can be selected; for a medium-sized coal storage bin, the KEYENCE GL-V21 type of optoelectronic reflection sensor can be selected; for a large open-air coal yard, the Sick WT270 - 2501 type of optoelectronic reflection sensor can be selected. This can improve the reliability of on-site data collection, which is beneficial for the subsequent controller to accurately calculate the coal pile height, and then timely and accurately control the working state of the driving motor, so that the coal accumulation under the belt conveyor frame can be effectively cleaned.

[0059] In summary, for the problem that there is often a large amount of accumulated coal under the frame of the belt conveyor that cannot be cleaned in time, this solution proposes a cleaning device that can automatically, conveniently and reliably clean the accumulated coal under the frame of the belt conveyor in time, effectively reduce the possibility of coal powder accumulation, increase the reliability of belt operation, improve the safety of equipment operation, reduce the risk of belt spontaneous combustion and damage, and at the same time reduce the workload of operating personnel and maintenance personnel.

Claims

1. A device for cleaning the coal accumulation under the frame of a belt conveyor, characterized in that, It includes a first gear (201) and a second gear (202) which are oppositely arranged. The first gear (201) is located outside the frame below the pressing roller. The second gear (202) is located inside the frame and is connected to the outer wall surface of the coal dropping pipe. A chain (203) is drivingly connected between the first gear (201) and the second gear (202). A scraper (205) and a photoelectric reflection sensor (204) are installed on the chain (203). The photoelectric reflection sensor (204) is communicatively connected to a controller, and is used for collecting the distance signal between the photoelectric reflection sensor (204) and the surface of the coal pile, and transmitting it to the controller; The controller is connected to a driving motor. The first gear (201) is connected to the output shaft of the driving motor. The controller is used for calculating the height of the coal pile and correspondingly controlling the working state of the driving motor.

2. The coal accumulation cleaning device under the frame for a belt conveyor according to claim 1, characterized in that, The driving motor and the first gear (201) are installed on a fixing seat. The bottom of the fixing seat is connected to the coal accumulation platform (206).

3. The coal accumulation cleaning device under the frame of a belt conveyor according to claim 1, characterized in that A connecting shaft is arranged on the outer wall surface of the coal dropping pipe. The second gear (202) is sleeved on the connecting shaft.

4. The coal accumulation cleaning device under the frame for a belt conveyor according to claim 3, characterized in that, The connecting shaft and the output shaft of the driving motor are at the same horizontal height.

5. The coal accumulation cleaning device under the frame of a belt conveyor according to claim 2, characterized in that, An opening is formed on the outer wall surface of the coal dropping pipe. The opening communicates with the end of the coal accumulation platform (206).

6. The coal accumulation cleaning device under the frame of a belt conveyor according to claim 1, characterized in that, The driving direction of the chain (203) is from the outside of the frame to the inside of the frame.

7. The coal accumulation cleaning device under the frame of a belt conveyor according to claim 1, characterized in that A tension regulator (207) is installed at the position of the first gear (201) for adjusting the tension of the chain (203).

8. A method for cleaning accumulated coal under the frame of a belt conveyor, which is applied to a device for cleaning accumulated coal under the frame of a belt conveyor according to any one of claims 1 to 7, characterized in that, It includes the following steps: S1. The photoelectric reflection sensor (204) collects the distance signal between itself and the surface of the coal pile, and transmits it to the controller; S2. The controller correspondingly calculates the current height of the coal pile. If the current height of the coal pile is greater than or equal to the preset threshold, then execute step S3, otherwise return to step S1; S3. The controller outputs a signal to control the driving motor to start rotating, correspondingly driving the first gear (201) to drive the second gear (202) to rotate, and synchronously driving the chain (203) to drive, so that the scraper (205) moves from the outside of the frame to the inside of the frame and sweeps the accumulated coal; During this process, the photoelectric reflection sensor (204) continuously collects the distance signal between itself and the surface of the coal pile, and the controller continuously updates and calculates the current height of the coal pile. If the current height of the coal pile is less than the preset threshold, then output a signal to control the driving motor to stop rotating, and then return to step S1.

9. A method for cleaning the coal accumulation under the frame of a belt conveyor according to claim 8, characterized in that, In step S1, the specific process of the photoelectric reflection sensor (204) collecting the distance signal between itself and the surface of the coal pile is: where D is the distance between the photoelectric reflection sensor (204) and the surface of the coal pile, f is the focal length of the lens, b is the emission-reception distance, and θ is the divergence angle of the emission beam.

10. A method for cleaning the coal accumulation under the frame of a belt conveyor according to claim 9, characterized in that, The formula for the controller to calculate the current height of the coal pile is: h = H0 - D·cos(α) where h is the height of the coal pile, H0 is the installation reference height of the photoelectric reflection sensor (204), and α is the inclination compensation coefficient of the photoelectric reflection sensor (204).

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