A large coal bunker stock level detection system

Abstract

The application discloses a large coal bunker stock level detection system and relates to the technical field of stock level measurement. The system comprises a radar stock level meter group, a DCS control system and a central control monitoring interface. The radar stock level meter group is arranged on each coal bunker. Each coal bunker is provided with a conical feed inlet on each side. A radar stock level meter is arranged on each side of each feed inlet for collecting the stock level data of the coal bunker at the corresponding feed inlet. The DCS control system is connected with each radar stock level meter through a signal cable for receiving and processing the stock level data collected by each radar stock level meter, and performing comprehensive calculation on the double-side stock level data collected by the two radar stock level meters of the same coal bunker to obtain the comprehensive stock level value of the coal bunker. The radar stock level meters are arranged in pairs on the sides of the conical feed inlets, and the comprehensive calculation of the DCS system can effectively identify the uneven stock phenomenon caused by the conical feed, and the system is suitable for the stock level detection scene of the closed and connected large coal bunker.

Description

Technical Field

[0001] This invention relates to the field of material level measurement technology, and specifically to a material level detection system for a large coal bunker. Background Technology

[0002] In industrial settings such as semi-coke production and coal storage and transportation, large coal bunkers serve as key facilities for raw material storage, and the accuracy and reliability of their material level detection directly affect the continuity and safety of the production process.

[0003] Currently, single-point radar level gauges are commonly used for coal bunker level detection. This technology involves installing a radar level gauge at a fixed location on the top or wall of the coal bunker, measuring the level height at that point by emitting electromagnetic waves into the bunker and receiving the reflected echoes from the coal surface. However, in practical applications, single-point radar level gauges have the following technical problems: I. Single-point measurements are insufficient to characterize the overall material level within the coal bunker. After entering the bunker via conveyor equipment, materials naturally accumulate, forming one or more "small peaks" with an irregularly undulating surface. Single-point radar can only measure the material level at a single point or within a very small area, failing to reflect the overall distribution of materials within the bunker. When the single-point measurement location happens to be at the top of a peak or the bottom of a valley, the measured value may deviate significantly from the average material level within the bunker, easily leading to misjudgments of the coal quantity in the bunker.

[0004] Second, the underground and coal bunker operating environments severely interfere with radar measurements. In underground coal bunkers or enclosed raw coal bunkers, there are unfavorable factors such as high dust concentration, high moisture content, and coal adhering to the walls. Simultaneously, the bunker opening structure may deform after long-term impact from large material flows, and there are numerous obstacles such as I-beams at the opening, leading to severe material splashing and scattering. All of these factors interfere with the radar echo signal, resulting in low accuracy and poor reliability of single-point radar level gauges in actual use.

[0005] To address the aforementioned issues, patent number CN118623976A discloses an underground coal bunker level detection system and method based on multi-radar scanning technology. This solution involves installing a first radar level gauge and a second radar level gauge at the connection between the bunker roof and wall. The two radar level gauges perform multi-point and multi-point omnidirectional level height scans within the bunker. A data processing module calculates the real-time comprehensive height and volume of the material based on the scan data. This solution, through multi-point scanning data, can reflect the material distribution within the bunker to a certain extent.

[0006] However, the aforementioned multi-radar scanning scheme is mainly applicable to top-mounted scenarios in underground coal bunkers. For large, enclosed raw coal bunkers located on the ground, especially those with a double-sided conical feed inlet structure and a counterweight sealing valve at the feed inlet, the bunker structure, feeding method, and sealing requirements differ from those of underground coal bunkers. Furthermore, in the CN118623976A scheme, both radar level gauges are positioned at the junction of the bunker top and the bunker wall. For situations with a large bunker height and the feed inlet located on the side wall, the distance between the top-mounted position and the feed inlet's drop point is significant, making it difficult to effectively detect localized material deviations caused by the conical feeding method.

[0007] Therefore, for the material level detection requirements of sealed, interconnected large coal bunkers (with large bunker height, double-sided conical feed inlets, equipped with heavy-duty sealing valves, and only a small observation port), how to achieve accurate detection of material level in a single bunker while preserving the bunker's sealing structure, and how to solve the problem of uneven material measurement caused by the double-sided conical feed inlets, remain urgent technical problems to be solved in this field. Summary of the Invention

[0008] To overcome the shortcomings of existing technologies, the present invention aims to provide a material level detection system for large coal bunkers. The present invention effectively identifies material deviation caused by conical feeding by deploying radar level gauges in pairs on the side of the conical feed inlet and combining them with the comprehensive calculation of the DCS system. It is suitable for material level detection scenarios in closed and interconnected large coal bunkers.

[0009] The technical solution adopted in this invention is as follows: A material level detection system for a large coal bunker includes: A radar level gauge is provided. Each coal bunker has two feed inlets. The radar level gauge is installed next to each feed inlet and is used to collect the material level data in the bunker at the corresponding feed inlet. The DCS control system is connected to each of the radar level gauges via signal cables to receive and process the level data collected by each of the radar level gauges. The central control monitoring interface is connected to the DCS control system and is used to display the material level information of each coal bunker in real time. The feed inlets are conical feed inlets located on both sides of the silo body. Each coal silo is equipped with two radar level gauges, which are installed on the sides of the two feed inlets of the coal silo to synchronously collect material level data from both sides. The DCS control system performs comprehensive calculation on the material level data collected by the two radar level gauges in the same coal silo to obtain the comprehensive material level value of the coal silo.

[0010] The specific workflow is as follows: The specific workflow is as follows: This system is used for level detection in enclosed raw coal bunkers. Each bunker has conical inlets on both sides. Two radar level gauges are installed beside each of the two conical inlets in each bunker. The two radar level gauges synchronously transmit electromagnetic waves into the bunker and receive the echoes reflected from the coal surface. Based on the time difference between transmission and reception, the local level height below their respective installation positions is calculated, i.e., the left-side level data and the right-side level data.

[0011] Each radar level gauge transmits the collected level data to the DCS control system via signal cables. After receiving two sets of level data from the same coal bunker, the DCS control system performs a comprehensive calculation—specifically, it fuses the level data from both sides according to a preset algorithm to obtain the comprehensive level value of the coal bunker, which reflects the average storage height of the material in the bunker.

[0012] The combined material level value and raw data from both sides are pushed to the central control monitoring interface for real-time display, allowing operators to view the material level information of each coal bunker from the central control room. Based on this information, operators can remotely adjust the belt conveyor speed and the start / stop and feeding direction of the feeding trolley, thereby controlling the feeding rhythm of the coal bunker.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By installing radar level gauges next to the feed inlets on both sides of a single coal bunker, local material level data on both sides of the bunker can be obtained simultaneously. Compared with a single radar level gauge or manual observation, this provides a more comprehensive reflection of the material distribution within the bunker.

[0014] 2. The comprehensive material level value obtained by the DCS control system after comprehensive processing of the material level data on both sides reduces the impact of the measured data deviating from the actual average material level due to the skewness of the material pile on one side to a certain extent.

[0015] 3. The system's central control monitoring interface allows operators to remotely view the material levels of each coal bunker from the central control room, eliminating the need for on-site inspections and reducing the workload of on-site checks.

[0016] In a preferred embodiment of the present invention, the comprehensive calculation is as follows: When the difference between the two material level data is within the preset range, the average value of the two material level data is taken as the comprehensive material level value; when the difference between the two material level data exceeds the preset range, it is determined that there is a material deviation in the silo and a material deviation alarm signal is output.

[0017] Beneficial effects: By introducing the two-sided data difference judgment logic, the system can identify abnormal conditions such as material misalignment within the silo and issue a material misalignment alarm to the operator, facilitating the operator's timely understanding of the material distribution status within the silo. For normal conditions where the difference is within the preset range, taking the average value as the comprehensive material level value makes the detection results more representative; for material misalignment conditions where the difference exceeds the preset range, the material misalignment alarm information can prompt the operator to pay attention to the material accumulation situation in the coal silo, assisting the operator in making corresponding control decisions.

[0018] In a preferred embodiment of the present invention, the DCS control system is equipped with a high-level alarm threshold and a low-level alarm threshold. When the material level reaches the high-level alarm threshold, a full-bin warning signal is issued, and when the material level reaches the low-level alarm threshold, an empty-bin warning signal is issued. The high-level alarm threshold and the low-level alarm threshold correspond to the critical full-bin material level and the critical empty-bin material level of the coal bunker, respectively.

[0019] Working principle: In the DCS control system, high-level alarm thresholds and low-level alarm thresholds are preset for each coal bunker. The high-level alarm threshold corresponds to the critical full level of the coal bunker, that is, when the level reaches this value, the coal bunker is close to full; the low-level alarm threshold corresponds to the critical empty level, that is, when the level drops to this value, the amount of raw coal in the bunker is low.

[0020] The system continuously compares the real-time overall material level with the two thresholds mentioned above: when the real-time material level reaches or exceeds the high-level alarm threshold, the system issues a full-warehouse warning signal; when the real-time material level drops to or falls below the low-level alarm threshold, the system issues an empty-warehouse warning signal. Both alarm signals are displayed on the central control monitoring interface, prompting operators to take appropriate actions to stop feeding or initiate replenishment.

[0021] Beneficial effects: By setting alarm thresholds at high and low levels, the system can automatically issue early warning signals when the material level reaches a critical state, replacing the manual periodic observation and subjective judgment of alarm methods. A full-bin warning allows operators to be promptly informed that the coal bin is nearing full, facilitating advance planning to stop feeding operations and reducing the risk of raw coal overflowing outside the bin due to overfeeding. An empty-bin warning allows operators to be promptly informed that the coal bin is low on stock, facilitating advance planning to replenish materials and reducing the risk of subsequent production processes being affected by raw material supply interruptions.

[0022] In a preferred embodiment of the present invention, the radar level gauge includes an antenna, a purge ring, and a conical cylinder. The antenna and the conical cylinder are coaxially arranged and spaced apart. The purge ring is disposed between the antenna and the conical cylinder and is located at the smaller end of the conical cylinder. The purge ring is connected to an external air source and has multiple air holes, forming an annular airflow between the antenna and the conical cylinder.

[0023] Beneficial effects: The purge ring is located at the smaller end of the conical cylinder (i.e., the side closer to the antenna) and is connected to an external compressed air source. The purge ring has multiple air holes; when air is supplied, the airflow is ejected from these holes, forming a ring-shaped airflow in the annular gap between the antenna and the conical cylinder. This airflow flows along the inner wall of the conical cylinder towards the larger end (i.e., the side facing the coal). This annular airflow forms a barrier in front of the radar antenna, preventing dust and moisture from the coal bunker from diffusing upwards and avoiding condensation or dust accumulation on the antenna surface.

[0024] In a preferred embodiment of the present invention, the plurality of air holes are all arranged obliquely to form a spiral airflow.

[0025] Beneficial effects: The multiple air holes on the purge ring are designed to be arranged obliquely (i.e., the axis of the air hole forms a certain angle with the antenna axis and deflects uniformly along the circumference). After compressed air is ejected from the oblique holes, it forms a spiral airflow that rotates and advances along the inner wall of the conical cylinder. Compared with the direct airflow, the spiral airflow has a longer sweeping path and a larger coverage area on the inner wall of the conical cylinder, which is beneficial for thoroughly removing the floating dust attached to the inner wall.

[0026] In a preferred embodiment of the present invention, a cover plate, a transmission mechanism, and a cylinder are also included. The external air source is connected to a branch air pipe, which is connected to the cylinder. The cover plate is hinged to the larger end of the conical cylinder. When the external air source supplies air, the cylinder can drive the cover plate to open through the transmission mechanism. When the external air source is closed, the cover plate seals the conical cylinder.

[0027] Beneficial effects: The opening and closing of the cover and the purging air supply share the same air source, eliminating the need for independent electrical or hydraulic control, thus simplifying the control system. As long as air is supplied, the cover opens and remains open; once the air supply stops, the cover automatically closes to prevent dust from entering due to accidental air interruption.

[0028] In a preferred embodiment of the present invention, a sealing ring is installed at the larger end of the conical cylinder.

[0029] Beneficial effect: The sealing ring fills the gap between the cover plate and the end face of the conical cylinder, improving the sealing performance.

[0030] In a preferred embodiment of the present invention, the transmission mechanism includes a housing, a gear, and a rack; the cylinder includes a cylinder body, a piston, a compression spring, and a rod; the housing and the cylinder body are fixedly connected and both are mounted on the outer wall of the conical cylinder; the gear is rotatably mounted inside the housing; the piston is slidably and sealed inside the cylinder body; one end of the cylinder body is connected to a branch air pipe; the other end of the cylinder body is provided with a sliding hole; the compression spring is mounted between the other end of the cylinder body and the piston; the rod is fixedly connected to the piston and can extend out of the sliding hole; the rack is fixedly connected to the rod and meshes with the gear; the outer wall of the housing is provided with an exhaust hole, and the gas at the other end of the cylinder body can be discharged into the housing through the sliding hole and discharged from the exhaust hole.

[0031] Beneficial effects: During air supply, compressed air enters from one end of the cylinder, pushing the piston to compress the spring and move forward. The rod drives the rack to move linearly, and the rack drives the gear to rotate, which in turn causes the cover to flip open. At this time, the gas at the other end of the cylinder (spring side) is discharged into the inner cavity of the housing through the sliding hole, and then discharged into the atmosphere through the exhaust hole on the housing. When air supply stops, the pressure inside the cylinder disappears, the compression spring releases its elasticity, pushes the piston back to its original position, the rack moves in the opposite direction, the gear reverses, and the cover closes. The single-acting spring reset cylinder can automatically reset in the event of air loss without external control signals, realizing power failure / air failure protection.

[0032] In a preferred embodiment of the present invention, the transmission mechanism and the cylinder are in two sets, which together drive the cover plate to flip.

[0033] Beneficial effects: For larger and heavier cover plates, dual-side drive can avoid uneven force and torsional deformation caused by single-side drive, ensuring smooth cover plate flipping.

[0034] In a preferred embodiment of the present invention, a dust removal block is provided at one end of the cover plate near the hinge, a first through hole is provided on the side wall of the dust removal block, and a second through hole communicating with the first through hole is provided on the dust removal block facing the center of the cover plate. The first through hole is connected to the exhaust hole through a hose, and a filter screen is provided in the second through hole. When the external air source stops supplying air, the piston retracts, and the second through hole generates negative pressure, which collects the dust inside the cover plate onto the filter screen inside the second through hole. When an external air source supplies air, the cover opens and the gas inside the cylinder near the housing enters the dust removal block through a hose and is discharged from the second through hole, removing the dust from the filter screen.

[0035] Beneficial effects: By utilizing the existing exhaust and back suction actions during cylinder operation, automatic dust removal of the inside of the cover can be achieved without additional air circuits or electronic controls. The dust suction and exhaust actions occur synchronously with the opening and closing process of the cover; each time the door is closed, accumulated dust is collected, and each time the door is opened, the filter screen is cleaned. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the antenna section in the open state in Embodiment 2 of the large coal bunker material level detection system of the present invention; Figure 2 This is a schematic diagram of the antenna section in the closed state in Embodiment 2 of the large coal bunker material level detection system of the present invention; Figure 3 This is a three-dimensional sectional view of the transmission mechanism in Embodiment 2 of the large coal bunker material level detection system of the present invention; Figure 4 This is a schematic diagram of the position of the ash removal block in Embodiment 3 of the large coal bunker material level detection system of the present invention; Figure 5 This is a cross-sectional view of the ash removal block in Embodiment 3 of the coal bunker level detection system of the present invention.

[0037] The reference numerals in the attached drawings include: antenna 1, purge ring 2, air hole 21, conical cylinder 3, cover plate 4, transmission mechanism 5, housing 51, gear 52, rack 53, cylinder 6, cylinder body 61, piston 62, compression spring 63, rod body 64, sliding hole 65, branch air pipe 7, sealing ring 8, dust removal block 9, first through hole 91, second through hole 92, filter screen 93, and hose 94. Detailed Implementation

[0038] Typical embodiments embodying the features and advantages of the present invention will be specifically described in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0039] In the description of this application, the terms "first", "second", etc. are used only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the structure referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0040] Example 1 This embodiment provides a material level detection system for large coal silos, applied to the sealed large coal silos in the raw coal storage process of semi-coke production. In this application scenario, 15 large coal silos are set up, interconnected. Each silo has an overall height of 15 to 25 meters and a sealed structure. A conical inlet is located on each side of the silo. Raw coal is fed into the silo through the conical inlets via a belt conveyor and a mobile feeding trolley. Each inlet is equipped with a counterweight sealing valve to maintain the silo's seal after feeding. A small observation port is also provided on the silo.

[0041] The material level detection system for the large coal bunker in this embodiment includes a radar level gauge group, a DCS control system, and a central control monitoring interface.

[0042] Radar level gauge units are installed on each coal bunker. Specifically, each coal bunker has two conical feed inlets, and a radar level gauge is installed beside each feed inlet. That is, each coal bunker has two radar level gauges, one installed beside each of the two feed inlets, to collect local material level data below the corresponding feed inlet. The two radar level gauges operate synchronously to collect material level data on both sides of the coal bunker at the same time, i.e., the left and right material level data.

[0043] As an optional installation method in this embodiment, the radar level gauge is installed at the existing mounting points around the feed inlet, such as the steel structure support or flange connection surface next to the feed inlet. This installation method does not require additional holes to be drilled in the top or side wall of the coal bunker, does not damage the original sealing structure of the coal bunker, and does not affect the normal opening and closing operation of the feed inlet counterweight sealing valve. The radar level gauge's detection direction is towards the surface of the coal inside the bunker, and the electromagnetic waves it emits can penetrate the small amount of dust present in the bunker, generating a reflected echo after reaching the coal surface.

[0044] As an optional configuration in this embodiment, the radar level gauge is a frequency-modulated continuous wave radar level gauge with an operating frequency of 24GHz or 80GHz. The measuring range is selected to be 30 meters based on the height of the coal bunker, and the accuracy is ±3mm. The radar level gauge has explosion-proof certification to meet the dust explosion-proof requirements of the coal bunker area.

[0045] The DCS control system is connected to each radar level gauge via shielded signal cables. As an optional signal transmission method in this embodiment, each radar level gauge transmits the collected level data to the DCS control system's I / O card in real time via a 4-20mA analog current signal. Alternatively, each radar level gauge transmits the level data to the DCS control system digitally via the RS485 communication protocol.

[0046] After receiving the level data transmitted from each radar level gauge, the DCS control system performs comprehensive calculations on the two sets of data for each coal bunker. Specifically, the DCS control system is pre-configured with comprehensive calculation logic, which merges the dual-side level data collected by the two radar level gauges in the same coal bunker to obtain the comprehensive level value of the coal bunker. The comprehensive level value reflects the average storage height of the material in the coal bunker.

[0047] In this embodiment, the specific logic of the comprehensive calculation is as follows: The DCS control system first acquires the left-side material level data collected by the left-side radar level gauge and the right-side material level data collected by the right-side radar level gauge in the same coal bunker, and calculates the difference. When the difference ΔH is within a preset range (e.g., the preset range is 0 to 0.5 meters), the system determines that the material accumulation height on both sides of the bunker is basically similar, and takes the average value of the material level data on both sides as the comprehensive material level value of the coal bunker. When the difference ΔH exceeds the preset range (e.g., greater than 0.5 meters), the system determines that there is a significant difference in the material accumulation height on both sides of the bunker, that is, a material deviation occurs. At this time, the system still calculates and outputs the comprehensive material level value (average value), and at the same time generates an additional material deviation alarm signal.

[0048] The central control monitoring interface is connected to the DCS control system to display the material level information of each coal bunker in real time. The DCS control system pushes the overall material level value and raw data from both sides to the central control monitoring interface. The central control monitoring interface displays the material level data of each coal bunker in a graphical way, such as displaying the left material level, right material level and overall material level of each coal bunker simultaneously in a bar chart, or listing each data item in the form of a numerical table.

[0049] Operators can view the material level information of all 15 coal bunkers in real time through the central control monitoring interface in the control room. Based on this information, operators can remotely adjust the belt conveyor speed and the start / stop and feeding direction of the feeding trolley through the DCS control system to control the feeding rhythm of the coal bunkers.

[0050] The system workflow is as follows: Raw coal is conveyed by belt conveyor to a mobile feeding trolley. After the feeding trolley moves to the conical inlet of the target coal bunker, it opens the counterweight sealing valve, feeding the raw coal from the conical inlet into the sealed large coal bunker. During the feeding process and between feeding intervals, radar level gauges installed next to the inlets on both sides of the bunker continuously operate, emitting electromagnetic waves into the bunker and receiving the echoes reflected from the coal surface. Based on the time difference between transmission and reception, the local material level height below their respective installation positions is calculated.

[0051] Each radar level gauge transmits real-time level data to the DCS control system via signal cables. The DCS control system performs comprehensive calculations on the two sets of data from the same coal bunker to obtain the overall level value for that bunker. The overall level value and the original data from both sides are simultaneously displayed on the central control monitoring interface.

[0052] When the central control monitoring interface shows that the material level of a certain coal bunker is low, the operator remotely starts the feeding trolley to replenish the material to the coal bunker; when the central control monitoring interface shows that the material level of a certain coal bunker is close to full, the operator remotely stops the feeding of the coal bunker and switches the feeding trolley to other coal bunkers that need to be fed.

[0053] Throughout the entire detection and control process, operators do not need to go to the coal bunker site for on-site observation; the entire process is completed in the central control room.

[0054] Example 2 like Figure 1 and Figure 2 As shown, in a preferred embodiment of the present invention, the radar level gauge includes an antenna 1, a purge ring 2, and a conical cylinder 3.

[0055] The antenna 1 is coaxially arranged with the conical cylinder 3, and there is an annular gap between the antenna 1 and the inner wall of the conical cylinder 3. The conical cylinder 3 is inverted cone-shaped, with its smaller end closer to the antenna 1 and its larger end facing the coal side (i.e., towards the inside of the coal bunker). The purge ring 2 is disposed between the antenna 1 and the conical cylinder 3, and is located at the smaller end of the conical cylinder 3. The purge ring 2 is connected to an external air source through a main air supply pipeline, and multiple air holes 21 are evenly distributed around the circumference of the purge ring 2.

[0056] When an external air source supplies air, compressed air enters the purge ring 2 through the main air supply pipeline and is ejected from multiple air holes 21, forming an annular airflow in the annular gap between the antenna 1 and the conical cylinder 3. This annular airflow flows along the inner wall of the conical cylinder 3 towards the larger end, i.e., towards the coal side, forming an air curtain barrier in front of the radar antenna 1. This air curtain barrier can effectively prevent dust and water vapor in the coal bunker from diffusing upward along the inner wall of the conical cylinder 3, avoiding dust deposition on the surface of the radar antenna 1 or water vapor condensation on the surface of the antenna 1, thus ensuring the long-term stability and accuracy of radar measurements.

[0057] In other embodiments, the plurality of air holes 21 on the purge ring 2 may be arranged obliquely. Specifically, the axis of each air hole 21 forms a predetermined angle (e.g., 30°~60°) with the axis of the antenna 1, and each air hole 21 is uniformly deflected by the same angle along the circumference of the purge ring 2. When an external air source supplies air, compressed air is ejected from each oblique air hole 21 and forms a spiral airflow that rotates and advances along the inner wall of the conical cylinder 3. Compared with the direct airflow, the spiral airflow has a longer sweeping path and a larger coverage area on the inner wall of the conical cylinder 3, which can more comprehensively remove the floating dust attached to the inner wall of the conical cylinder 3 and effectively prevent dust from accumulating and caking on the inner wall of the conical cylinder 3.

[0058] The system also includes a cover plate 4, a transmission mechanism 5, and a cylinder 6. A branch air pipe 7 is connected to the main air supply pipeline of the external air source, and the branch air pipe 7 is connected to the air inlet of the cylinder 6. One side of the cover plate 4 is hinged to the edge of the larger end face of the conical cylinder 3, and the shape and size of the cover plate 4 are adapted to the shape and size of the port of the larger end of the conical cylinder 3.

[0059] There are two sets of transmission mechanism 5 and cylinder 6. The two sets of transmission mechanism 5 and cylinder 6 are respectively arranged on both sides of the cover plate 4 or at both ends of the rotating rod. The two sets of structures are symmetrically arranged and operate synchronously to jointly drive the cover plate 4 to flip.

[0060] When the external air source supplies air, compressed air simultaneously enters the purge ring 2 and the cylinder 6. The cylinder 6, through the transmission mechanism 5, drives the cover plate 4 to flip open around the hinge, opening the larger end port of the conical cylinder 3 for radar beam transmission and reception. When the external air source is shut off, the cylinder 6 loses its driving force, and the cover plate 4, under the action of the reset mechanism, flips in the opposite direction, resealing the larger end port of the conical cylinder 3.

[0061] The opening and closing of the cover plate 4 and the purging air supply of the purging ring 2 share the same air source, eliminating the need for independent electrical or hydraulic control and simplifying the control system structure. Since they operate synchronously, as long as the air source is supplied, the cover plate 4 opens and remains open, while the purging ring 2 continues to operate. If the air source is unexpectedly interrupted, the cover plate 4 automatically closes, physically isolating the interior of the conical cylinder 3 from the coal bunker environment and preventing dust backflow into the conical cylinder 3 due to accidental air supply interruption.

[0062] A sealing ring 8 is installed on the larger end face of the conical cylinder 3. The sealing ring 8 can be made of wear-resistant and aging-resistant rubber or polyurethane elastic material. When the cover plate 4 is closed, the inner surface of the cover plate 4 presses against the sealing ring 8, and the sealing ring 8 undergoes elastic deformation, filling any small gaps that may exist between the cover plate 4 and the end face of the conical cylinder 3, forming a reliable contact seal, and further improving the airtightness of the cover plate 4 in the closed state.

[0063] Among them, such as Figure 3 As shown, the transmission mechanism 5 includes a housing 51, a gear 52, and a rack 53. The cylinder 6 is a single-acting spring-return cylinder 6, including a cylinder body 61, a piston 62, a compression spring 63, and a rod 64. The housing 51 and the cylinder body 61 are fixedly connected as a single unit and are jointly fixedly mounted on the outer wall of the conical cylinder 3. The gear 52 is rotatably mounted inside the housing 51 via a rotating shaft, and the rotating shaft of the gear 52 is coaxially and fixedly connected to the hinge shaft of the cover plate 4.

[0064] The piston 62 is slidably and sealingly installed inside the cylinder 61, dividing the inner cavity of the cylinder 61 into a rod chamber and a rodless chamber. One end of the cylinder 61 (i.e., the rodless chamber end) is connected to an external air source through the branch air pipe 7. The other end of the cylinder 61 (i.e., the rod chamber end) is provided with a sliding hole 65 (the sliding hole 65 and the rod 64 have a certain gap in a local area to facilitate air flow). The compression spring 63 is installed between the inner wall of the rod chamber end of the cylinder 61 and the piston 62. The compression spring 63 is always in a compressed state, applying a thrust to the piston 62 towards the rodless chamber. One end of the rod 64 is fixedly connected to the piston 62, and the other end of the rod 64 passes through the sliding hole 65 and extends out of the cylinder 61. The rack 53 is fixed to the end of the rod 64 that extends out of the cylinder 61, and the rack 53 meshes with the gear 52.

[0065] An exhaust port is provided on the outer wall of the housing 51. Gas in the rod chamber of the cylinder 61 can be discharged into the inner cavity of the housing 51 through the sliding hole 65 and discharged to the outside atmosphere through the exhaust port of the housing 51.

[0066] The working principle of this embodiment is as follows: When an external air source supplies air, compressed air enters the rodless chamber of the cylinder 61 through the branch air pipe 7, pushing the piston 62 to move towards the rod chamber against the elastic force of the compression spring 63. The piston 62 drives the rod 64 and the rack 53 to move synchronously in a straight line. The rack 53 drives the gear 52 to rotate, and the gear 52 drives the cover plate 4 to flip open via a rotating shaft or rotating rod. At this time, the gas in the rod chamber of the cylinder 61 is compressed by the piston 62, discharged into the inner cavity of the housing 51 through the sliding hole 65, and then discharged to the atmosphere through the exhaust hole of the housing 51.

[0067] When the external air source stops supplying air, the pressure in the rodless chamber of the cylinder 61 disappears, the compression spring 63 releases its elastic force, and pushes the piston 62 back to its original position towards the rodless chamber. The piston 62 drives the rod 64 and the rack 53 to move in opposite linear directions. The rack 53 drives the gear 52 to rotate in the opposite direction, and the cover plate 4 flips in the opposite direction to close.

[0068] This embodiment employs a single-acting spring-reset cylinder 6, which automatically resets upon gas loss without external control signals, achieving power / gas failure protection. Simultaneously, the gear 52 and rack 53 transmission offers advantages such as precise transmission ratio and no slippage loss. The flipping angle of the cover plate 4 strictly corresponds to the stroke of the piston 62, ensuring high repeatability. The design of the cylinder body 61, where gas in the rod chamber is discharged into the housing 51 via the sliding hole 65 and then discharged through the exhaust hole, ensures that the exhaust path passes through the interior of the housing 51, buffering exhaust noise and preventing high-speed airflow from directly expelling dust.

[0069] Example 3 like Figure 4 and Figure 5 As shown, in a preferred embodiment of the present invention, based on the above embodiment, a dust removal block 9 is provided at one end of the cover plate 4 near the hinge. The dust removal block 9 is fixedly installed on the inner surface of the cover plate 4 (i.e., the side facing the inside of the conical cylinder 3) near the hinge.

[0070] The dust removal block 9 has first through holes 91 on both sides and multiple second through holes 92 on the side of the dust removal block 9 facing the center of the cover plate 4. The second through holes 92 and the first through holes 91 are interconnected inside the dust removal block 9. The first through holes 91 are connected to the exhaust port of the housing 51 through a flexible hose 94. A filter screen 93 is installed inside the second through hole 92, which is used to intercept and collect dust particles in the airflow.

[0071] The working principle of this embodiment is as follows: When the external air source stops supplying air, the compression spring 63 pushes the piston 62 back towards the rodless chamber, increasing the volume of the rod chamber of the cylinder 61 (i.e., the side near the housing 51). This creates a certain negative pressure (i.e., suction effect) within the inner cavity of the housing 51 and the hose 94. This negative pressure is transmitted through the hose 94 to the first through hole 91 and the second through hole 92 of the dust removal block 9, creating suction at the second through hole 92. This suction draws the floating dust adhering to the inner surface of the cover plate 4 into the second through hole 92, where it is intercepted and collected by the filter screen 93. This process occurs synchronously with the closing action of the cover plate 4, automatically completing the collection of accumulated dust inside the cover plate 4 using the suction generated by the retraction of the piston 62.

[0072] When the external air source supplies air again, compressed air enters the rodless chamber of the cylinder 61, pushing the piston 62 towards the rod chamber. The gas in the rod chamber of the cylinder 61 is compressed and sequentially passes through the sliding hole 65, the inner cavity of the housing 51, the exhaust hole of the housing 51, the hose 94, and the first through hole 91 into the second through hole 92 of the dust removal block 9. The gas is then ejected outward from the second through hole 92, blowing off the dust collected on the filter screen 93, thus automatically cleaning the filter screen 93. This process occurs synchronously with the opening of the cover plate 4, and the exhaust generated by the piston 62 automatically clears the blockage of the filter screen 93.

[0073] This embodiment utilizes the existing exhaust and suction actions during the operation of cylinder 6 to achieve automatic dust removal from the inside of cover 4 without the need for additional independent air circuits or electronic control components. The dust suction and exhaust actions are synchronized with the opening and closing process of cover 4; each time the door is closed, accumulated dust is collected, and each time it is opened, the filter 93 is cleaned, achieving a certain degree of self-cleaning. The filter 93 effectively intercepts inhaled coarse dust particles, preventing them from entering the hose 94 and the inner cavity of the housing 51, thus protecting the transmission components from dust contamination.

[0074] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A material level detection system for a large coal bunker, characterized in that... ,include: A radar level gauge is provided. Each coal bunker has two feed inlets. The radar level gauge is installed next to each feed inlet and is used to collect the material level data in the bunker at the corresponding feed inlet. The DCS control system is connected to each of the radar level gauges via signal cables to receive and process the level data collected by each of the radar level gauges. The central control monitoring interface is connected to the DCS control system and is used to display the material level information of each coal bunker in real time. The feed inlets are conical feed inlets located on both sides of the silo body. Each coal silo is equipped with two radar level gauges, which are installed on the sides of the two feed inlets of the coal silo to synchronously collect material level data from both sides. The DCS control system performs comprehensive calculation on the material level data collected by the two radar level gauges in the same coal silo to obtain the comprehensive material level value of the coal silo.

2. The material level detection system for large coal bunkers according to claim 1, characterized in that, The specific steps of the comprehensive calculation are as follows: When the difference between the two material level data is within the preset range, the average value of the two material level data is taken as the comprehensive material level value; when the difference between the two material level data exceeds the preset range, it is determined that there is a material deviation in the silo and a material deviation alarm signal is output.

3. The material level detection system for large coal bunkers according to claim 1, characterized in that: The DCS control system is equipped with a high-level alarm threshold and a low-level alarm threshold. When the material level reaches the high-level alarm threshold, a full-bin warning signal is issued, and when the material level reaches the low-level alarm threshold, an empty-bin warning signal is issued. The high-level alarm threshold and the low-level alarm threshold correspond to the critical full-bin material level and the critical empty-bin material level of the coal bunker, respectively.

4. The material level detection system for large coal bunkers according to claim 1, characterized in that: The radar level gauge includes an antenna, a purge ring, and a conical cylinder. The antenna and the conical cylinder are coaxially arranged and spaced apart. The purge ring is disposed between the antenna and the conical cylinder and is located at the smaller end of the conical cylinder. The purge ring is connected to an external air source and has multiple air holes, forming an annular airflow between the antenna and the conical cylinder.

5. The material level detection system for large coal bunkers according to claim 4, characterized in that: The multiple air holes are all arranged at an angle to form a spiral airflow.

6. The material level detection system for large coal bunkers according to claim 4, characterized in that: It also includes a cover plate, a transmission mechanism and a cylinder. The external air source is connected to a branch air pipe, which is connected to the cylinder. The cover plate is hinged to the larger end of the conical cylinder. When the external air source supplies air, the cylinder can drive the cover plate to open through the transmission mechanism. When the external air source is closed, the cover plate seals the conical cylinder.

7. The material level detection system for large coal bunkers according to claim 6, characterized in that: A sealing ring is installed at the larger end of the conical cylinder.

8. The material level detection system for large coal bunkers according to claim 6, characterized in that: The transmission mechanism includes a housing, gears and racks, and the cylinder includes a cylinder body, piston, compression spring and rod. The housing and cylinder are fixedly connected and both are mounted on the outer wall of the conical cylinder. The gear is rotatably mounted inside the housing, and the piston is slidably and sealed inside the cylinder. One end of the cylinder is connected to a branch gas pipe, and the other end of the cylinder is provided with a sliding hole. The compression spring is installed between the other end of the cylinder and the piston. The rod is fixedly connected to the piston and can extend out of the sliding hole. The rack is fixedly connected to the rod and meshes with the gear. The outer wall of the housing is provided with an exhaust hole, and the gas at the other end of the cylinder can be discharged into the housing through the sliding hole and discharged from the exhaust hole.

9. The material level detection system for large coal bunkers according to claim 6, characterized in that: The transmission mechanism and cylinders are in two sets, which together drive the cover plate to flip.

10. The material level detection system for large coal bunkers according to claim 8, characterized in that: The cover plate is provided with a dust removal block at one end near the hinge. The side wall of the dust removal block is provided with a first through hole. The dust removal block is provided with a second through hole that communicates with the first through hole facing the center of the cover plate. The first through hole is connected to the exhaust hole through a hose. The second through hole is provided with a filter screen. When the external air source stops supplying air, the piston retracts, and the second through hole generates negative pressure, which collects the dust inside the cover plate onto the filter screen inside the second through hole. When an external air source supplies air, the cover opens and the gas inside the cylinder near the housing enters the dust removal block through a hose and is discharged from the second through hole, removing the dust from the filter screen.

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