Coal drop pipe jamming detection device and detection method based on radio frequency admittance level controller

Abstract

The invention relates to a coal drop pipe jamming detection device and method based on a radio frequency admittance level controller, the device comprises a coal drop pipe body (3), the coal drop pipe body (3) comprises a plurality of sections of pipe bodies which are coaxially arranged and can be stretched and contracted, a lead part is arranged between every two adjacent pipe bodies, and when and only when every two adjacent pipe bodies are completely stretched or completely contracted, every two adjacent pipe bodies are conducted; the radio frequency admittance module is connected with the coal drop pipe body (3), the radio frequency admittance module comprises a receiving end (1) and a transmitting end (2) which are located on the outer surfaces of the two ends of the coal drop pipe body (3) respectively, and the radio frequency admittance module is used for transmitting and receiving radio frequency signals; the signal sensor is electrically connected with the receiving end (1) and is used for generating a switching value signal according to the received radio frequency signal; and the control system is in communication connection with the signal sensor and is used for judging whether the coal drop pipe body (3) is jammed or not based on the switching value signal.

Description

Technical Field

[0001] The present invention relates to the technical field of material conveying, and in particular to a coal drop pipe jam detection device and method based on a radio frequency admittance level controller. Background Art

[0002] A drop tube is a common device that uses gravity and kinetic energy to transport materials from high to low locations. Telescopic drop tubes, with their retractable and stretchable properties, can flexibly adjust the stacking height of materials and are widely used in conveying bulk materials such as coal and ore. These tubes typically consist of multiple sections that slide relative to each other, and their overall length can be adjusted by stretching or contracting to accommodate varying discharge height requirements.

[0003] However, in actual operation, telescopic drop tubes face significant technical challenges: Coal and other conveying materials often contain sticky components, which can easily adhere to the inner wall of the drop tube. This adhered material, especially during repeated stretching and contraction, increases frictional resistance within the tube, hindering the expansion and contraction movement and causing a jam. If jamming is not detected and addressed promptly, it can cause tube deformation, damage to mechanical components, or even shut down the entire conveyor line, severely impacting production efficiency and increasing maintenance costs.

[0004] Currently, traditional methods for detecting jams in telescopic drop tubes rely primarily on manual inspections or indirect monitoring using mechanical stress sensors. Manual inspections suffer from poor real-time performance and high labor intensity, making it difficult to detect early signs of jams under complex working conditions. Mechanical stress sensors, on the other hand, are complex to install and debug and are susceptible to interference from environmental vibrations and material impact, resulting in insufficient detection accuracy.

[0005] In summary, the existing technology lacks an effective means to directly and reliably judge the jamming state of the blanking tube. There is an urgent need for a detection device based on a new sensing principle to achieve accurate identification of the jamming phenomenon and real-time early warning, so as to avoid equipment damage and production interruption caused by jamming problems. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a coal drop pipe jam detection device and detection method based on a radio frequency admittance level controller. The jam state is accurately judged by the change of the conductivity coefficient, and real-time monitoring and early warning of coal drop pipe jams are realized, thereby avoiding equipment damage and production interruptions caused by jams and improving the safety and reliability of the coal transportation system.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] According to one aspect of the present invention, a device for detecting coal drop pipe jamming based on a radio frequency admittance level controller is provided, comprising:

[0009] The coal drop pipe body comprises a plurality of coaxially arranged and stretchable and contractible tubes, with a lead portion provided between adjacent tubes. When and only when two adjacent tubes are fully stretched or fully contracted, the two adjacent tubes are connected;

[0010] A radio frequency admittance module is connected to the coal drop pipe body, and the radio frequency admittance module includes a receiving end and a transmitting end respectively located on the outer surfaces of both ends of the coal drop pipe body, for transmitting and receiving radio frequency signals;

[0011] a signal sensor, electrically connected to the receiving end, and configured to generate a switching signal according to the received radio frequency signal;

[0012] The control system is in communication with the signal sensor and is used to determine whether the coal drop pipe body is stuck based on the switch signal.

[0013] As a preferred technical solution, a transmitter and receiver are paired and located on the outer walls of adjacent segments of a telescopic coal drop pipe. The detector transmits radio frequency signals, while the receiver receives RF signals transmitted through the segments and material. Adjacent segments are separated by insulating material, making them independent conductors in their partially extended or contracted states. Adherence to material or wear of the insulating material increases conductivity, allowing signal transmission.

[0014] As a preferred technical solution, it also includes:

[0015] The insulating material is arranged on the inner wall of each interrupted tube section and is used to achieve insulation between two adjacent tube sections in a non-fully stretched or fully contracted state.

[0016] As a preferred technical solution, the insulating material is arranged around the circumference of the adjacent pipe segments, and its thickness is not less than the expansion and contraction gap of the pipe body.

[0017] As a preferred technical solution, the insulating material is one of polytetrafluoroethylene, epoxy resin or silicone rubber, and its surface roughness is smaller than the surface roughness of the inner wall of the coal drop pipe.

[0018] As a preferred technical solution, the signal sensor is a radio frequency admittance level controller, which has a built-in frequency analysis module for detecting frequency changes of the radio frequency signal received by the receiving end.

[0019] As a preferred technical solution, the control system includes a signal processing unit and an alarm module. The signal processing unit pre-stores a standard electrical signal when the coal drop pipe is not stuck, and the alarm module is used to issue an early warning when it is determined to be stuck.

[0020] As a preferred technical solution, the detection device further includes a signal transmission module for transmitting the switch signal to the coal conveying program control system via wired or wireless means.

[0021] As a preferred technical solution, it includes multiple groups of receiving ends and transmitting ends.

[0022] According to another aspect of the present invention, a method for detecting a coal drop pipe jam based on a radio frequency admittance level controller is provided. The method is implemented based on the aforementioned coal drop pipe jam detection device based on a radio frequency admittance level controller. The method comprises the following steps:

[0023] When the coal drop pipe body is in a fully stretched or fully contracted state, an initial electrical signal is collected through the receiving end and the transmitting end of the radio frequency admittance module as a standard signal of a non-jamming state;

[0024] When the coal drop pipe body is in a non-fully stretched or fully contracted state, the radio frequency signal received by the receiving end is monitored in real time to generate a real-time electrical signal;

[0025] The real-time electrical signal is compared with the standard signal. If the conductivity of the real-time electrical signal exceeds a preset threshold, it is determined that the coal drop pipe body is stuck and an alarm is triggered.

[0026] As a preferred technical solution, the method for setting the preset threshold includes:

[0027] Record the conductivity of the coal drop pipe body in a normal expansion and contraction state without any sticking materials as a reference value;

[0028] According to the material properties and expansion and contraction frequency of the coal drop pipe body, 1.5-3 times of the reference value is set as the preset threshold;

[0029] The change in the conductivity coefficient is reflected by the attenuation amplitude of the frequency signal of the radio frequency admittance level controller.

[0030] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0031] (1) Improved detection principle: The present invention uses radio frequency admittance to directly monitor the changes in the conductive properties between pipe sections. Compared with traditional mechanical stress detection, it has stronger resistance to environmental interference and is more sensitive to the jamming caused by the adhesion of viscous materials.

[0032] (2) Real-time and reliability: The present invention realizes real-time judgment and early warning of jamming status through the coordination of signal sensors and control systems, avoids the lag of manual inspection, and significantly improves detection efficiency and accuracy.

[0033] (3) Simple structure and easy implementation: The combination design of the insulating material and the radio frequency admittance device of the present invention does not require major modifications to the coal drop pipe body, is easy to install and debug, and is compatible with the existing telescopic coal drop pipe structure.

[0034] (4) Significant fault prevention effect: The present invention can effectively avoid mechanical wear, deformation and even shutdown accidents caused by pipe jamming by timely detecting jamming and issuing early warning, thereby reducing equipment maintenance costs and ensuring stable operation of the coal transportation system.

[0035] (5) Monitoring of various risks: When the pipe body is stuck, the coal causes the conductivity coefficient of the middle section of the pipe body to change, thereby achieving monitoring. When the insulating material is damaged, the middle section of the pipe body is directly conductive, the conductivity coefficient changes, and monitoring can also be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of a coal drop pipe jam detection device based on a radio frequency admittance level controller in an embodiment;

[0037] Figure 2 Flowchart of a method for detecting coal pipe jamming based on a radio frequency admittance level controller in an embodiment;

[0038] Figure 3 is a schematic diagram of an electronic device in an embodiment,

[0039] Among them, 1. receiving end, 2. transmitting end, 3. coal drop pipe body. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0041] Example 1

[0042] In view of the problems existing in the above-mentioned prior art, this embodiment provides a coal drop pipe jam detection device based on radio frequency admittance level controller, which is applicable to multi-section telescopic coal drop pipes in coal conveying systems. Figure 1 It is a schematic diagram of the coal drop pipe body 3 in the device in a fully retracted state.

[0043] 1. Device hardware composition.

[0044] 1. RF admittance detection end and receiving end.

[0045] A pair of transmitting terminals T1 and receiving terminals R1 are symmetrically installed on the outer walls of the two sections at the end of the multi-section telescopic coal drop pipe. They include radio frequency admittance sensor probes fixed by epoxy resin insulating brackets. The height of the brackets ensures that the probe axes are relatively arranged in the same horizontal plane with a spacing of 5 cm.

[0046] The transmitting end T1 is connected to a high-frequency signal generator with an output frequency of 100kHz to transmit radio frequency signals to the pipe segment at one end. The receiving end R1 is electrically connected to the pipe segment at the other end to receive signals transmitted through the medium between the pipe segments.

[0047] 2. Insulation materials.

[0048] At the connection between adjacent pipe sections A and B, a 5mm thick polytetrafluoroethylene insulating ring is embedded circumferentially. The inner diameter matches the outer diameter of the pipe section and its thickness is greater than the 3mm expansion and contraction gap of the pipe section, ensuring that A and B are electrically isolated by the insulating ring when the pipe section is fully stretched or fully contracted, forming an independent conductor.

[0049] The inner surface roughness of the insulating ring is Ra≤0.8μm, which is lower than the inner wall roughness of the coal drop pipe Ra≤1.6μm, reducing material adhesion.

[0050] 3. Signal sensor and control system.

[0051] The receiving end R1 is connected to the RF admittance level controller through a shielded cable. The controller has a built-in frequency analysis module to detect the frequency attenuation amplitude of the received signal in real time, thereby reflecting the change of the conductivity coefficient.

[0052] The control system includes a PLC control unit and a local alarm:

[0053] The PLC stores the standard signal when the pipe joint is fully stretched and has no adhesion. At this time, the insulating ring isolates A and B, and the signal strength at the receiving end is S0.

[0054] When the real-time value of the signal strength S is greater than or equal to 1.5 times S0 (i.e., the preset threshold value, which is calibrated according to the conductivity of the coal), the PLC determines that it is stuck, triggers the alarm to sound, and lights up the indicator light.

[0055] 2. Workflow.

[0056] Step 1: Standard signal calibration: The coal drop pipe is unloaded and fully extended or retracted. The detection end T1 transmits a signal, and the receiving end R1 collects the initial signal S0 as the baseline value of the non-jamming state.

[0057] Step 2: Real-time monitoring and jam detection. When the coal drop pipe is in operation, the detection end continuously transmits signals. If the inner wall of the pipe section becomes adhered to conductive media such as coal, or if the gap between the insulating ring decreases due to friction and wear, the conductivity coefficient between pipe sections A and B increases, and the signal strength S at the receiving end increases.

[0058] When S exceeds the preset threshold, such as 1.5 times S0, the controller generates a high-level switch signal, and the PLC triggers an alarm, prompting the operator to clean the sticky material on the inner wall of the pipe joint.

[0059] Example 2

[0060] Based on Example 1, this example is optimized for the remote monitoring requirements of a large-scale coal transportation system.

[0061] On the one hand, a set of detection ends and receiving ends are installed at the upper, middle and lower positions of each pair of adjacent pipe sections of the coal drop pipe, with a total of 3 sets / pipe section pairs, forming a circular detection array to cover the circumferential adhesion situation of the pipe sections and avoid single-point detection blind spots.

[0062] On the other hand, a silicone rubber insulating sleeve is used instead of an insulating ring. It is 8mm thick and has a built-in metal skeleton to enhance wear resistance and adapt to high-frequency expansion and contraction, such as working conditions above 50 times per hour. The silicone rubber surface is coated with a polytetrafluoroethylene anti-stick coating to further reduce material adhesion.

[0063] In addition, an additional wireless transmission module is set up, and the signal sensor uploads the switch signal to the coal conveying programmable control system DCS in real time through the transmission module. The DCS interface displays the jamming status of each pipe section and links it to the coal drop pipe extension and retraction motor control circuit. When the alarm is first triggered, the DCS sends a shutdown command to prohibit the coal drop pipe from continuing to extend and retract. If the alarm continues for more than 5 minutes, the pipe section vibrator is linked to automatically clear the blockage.

[0064] Finally, the control system adds a historical data learning function. Based on the normal operating signals of the coal drop pipe in the past 30 days, that is, the signal fluctuation range when there is no jamming, the preset threshold is automatically corrected, and the baseline value is dynamically updated to the S0±5% fluctuation range to adapt to the conductivity differences of different coal qualities (such as bituminous coal and lignite).

[0065] Example 3

[0066] See also Figure 2 This embodiment provides a method for detecting a coal drop pipe jam based on a radio frequency admittance level controller, which is implemented based on the coal drop pipe jam detection device based on a radio frequency admittance level controller of the previous embodiment.

[0067] The method comprises the following steps:

[0068] Step S1, standard signal calibration, when the coal drop pipe body 3 is in a fully stretched or fully contracted state, the initial electrical signal is collected through the receiving end 1 and the transmitting end 2 of the radio frequency admittance module as a standard signal of the non-jamming state.

[0069] Specifically, before calibration, the coal drop pipe must be unloaded and in a fully extended or contracted state. Insulation rings must completely isolate adjacent pipe sections, ensuring electrical insulation between them. The RF admittance probe is controlled to transmit a 100kHz high-frequency signal. The receiver continuously collects the electrical signal between the pipe sections 10 times, with a voltage value of 2.0V±0.1V. The average value of 2.0V is taken as the standard signal S0 for a no-jam state. The conductivity reference value G0=0.5μS is also recorded at this time.

[0070] Step S2: Real-time signal monitoring and processing: When the coal drop pipe body 3 is in a partially stretched or fully contracted state, the radio frequency signal received by the receiving end 1 is monitored in real time to generate a real-time electrical signal.

[0071] Specifically, regarding the signal acquisition frequency, when the coal drop pipe is in operation, that is, when the material is extended or stationary, the detection end continuously transmits signals, and the receiving end collects real-time electrical signals S at a frequency of 10 times / second. i , and synchronously transmit it to the RF admittance level controller. The controller has a built-in filter to reduce the noise of the signal (remove abnormal values with ±10% fluctuations) and output the average signal value S after stabilization every 5 seconds. avg According to the formula Calculate the real-time conductivity coefficient G to reflect the strength of the conductive path formed between pipe sections due to material adhesion.

[0072] Step S3, jamming judgment and warning. Specifically, step S3 may include steps S301-S303:

[0073] Step S301: threshold setting. Preset jam warning threshold G th =1.5G0, that is, the conductivity coefficient exceeds 1.5 times the benchmark value. This threshold is calibrated based on the average conductivity of the coal material, resistivity ≤104Ω·m and the expansion and contraction frequency of the coal drop pipe 20 times / hour.

[0074] Step S302, judgment logic. When G≥G is detected three times in a certain period of time (within 15 seconds), th When the coal drop pipe is stuck, the control system determines that it is stuck, immediately triggers the local sound and light alarm, and sends a switch signal to the coal conveying program control system.

[0075] Step S303: Early warning response: After receiving the alarm, the operator remotely checks the location of the stuck pipe section through the coal conveying program control system, suspends the extension and retraction of the coal drop pipe, and arranges for manual cleaning.

[0076] Example 4

[0077] Based on Examples 2 and 3, this embodiment optimizes processing for coal quality fluctuations, such as complex working conditions of alternating transportation of lignite and bituminous coal, through adaptive threshold adjustment and multi-dimensional judgment.

[0078] Specifically, the process of adaptive threshold adjustment includes:

[0079] Step 1: Historical data collection. The system automatically records the standard signal S of the coal drop pipe in the no-load tension state every day. 0' , that is, collect the average value for three consecutive times to form a 7-day sliding window database, and calculate the fluctuation range of the benchmark value:

[0080]

[0081] ΔS=±5%×S 0_dyn

[0082] Among them, S 0_dyn is the baseline value, and ΔS is the fluctuation threshold.

[0083] Step 2: Adaptive calibration. When a new type of coal is detected by the coal quality sensor of the coal conveying system, it automatically switches to the corresponding reference value:

[0084] For lignite, considering its high moisture content and strong electrical conductivity, the reference value is corrected to S 0_dyn ×0.9;

[0085] For bituminous coal, considering its low moisture content and weak electrical conductivity, the reference value is corrected to S 0_dyn ×1.1.

[0086] The process of multi-signal fusion judgment includes:

[0087] Step 1: Using the layered detection layout in Example 2, install a set of detection end / receiving end at the upper, middle and lower positions of each pair of adjacent pipe sections of the coal drop pipe, for a total of 3 sets, to collect signal G respectively. up , G md , G dw .

[0088] Step 2: When any two groups of signals exceed the threshold G at the same time th =2.0×G 0_dy , or a single group of signals exceeds G for 5 consecutive times th =3.0×G 0_dyn When the vehicle is stuck, it is judged as stuck, thus avoiding single-point misjudgment.

[0089] Example 5

[0090] This embodiment provides an electronic device, including: one or more processors and a memory, wherein the memory stores one or more programs, and the one or more programs include instructions for executing the coal drop pipe jam detection method based on the radio frequency admittance level controller as described in Example 3 or 4.

[0091] like Figure 3As mentioned above, at the hardware level, the electronic device includes a processor, an internal bus, a network interface, a memory and a non-volatile memory, and may also include other hardware required for the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 2 Of course, in addition to software implementation, the present invention does not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc., that is, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0092] Memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

[0093] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory media such as modulated data signals and carrier waves.

[0094] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A coal drop pipe jam detection device based on radio frequency admittance level controller, characterized in that: include: The coal drop pipe body (3) comprises a plurality of coaxially arranged and stretchable and contractible tubes, with a lead portion provided between adjacent tubes. When and only when the two adjacent tubes are fully stretched or fully contracted, the two adjacent tubes are connected; A radio frequency admittance module is connected to the coal drop pipe body (3), and the radio frequency admittance module comprises a receiving end (1) and a transmitting end (2) respectively located on the outer surfaces of both ends of the coal drop pipe body (3), and is used for transmitting and receiving radio frequency signals; A signal sensor is electrically connected to the receiving end (1) and is used to generate a switching signal according to the received radio frequency signal; A control system is communicatively connected to the signal sensor and is used to determine whether the coal drop pipe body (3) is stuck based on the switch signal.

2. The device for detecting coal drop pipe jamming based on radio frequency admittance level controller according to claim 1, characterized in that: Also includes: The insulating material is arranged on the inner wall of each interrupted tube section and is used to achieve insulation between two adjacent tube sections in a non-fully stretched or fully contracted state.

3. The device for detecting coal drop pipe jamming based on radio frequency admittance level controller according to claim 2, characterized in that: The insulating material is arranged around the circumference of the adjacent pipe sections, and its thickness is not less than the expansion gap of the pipe body.

4. The device for detecting coal drop pipe jamming based on radio frequency admittance level controller according to claim 2, characterized in that: The insulating material is one of polytetrafluoroethylene, epoxy resin or silicone rubber, and the surface roughness of the insulating material is smaller than the surface roughness of the inner wall of the coal drop pipe.

5. The device for detecting coal drop pipe jamming based on radio frequency admittance level controller according to claim 1, characterized in that: The signal sensor is a radio frequency admittance level controller, which has a built-in frequency analysis module for detecting frequency changes of the radio frequency signal received by the receiving end (1).

6. The device for detecting coal drop pipe jamming based on radio frequency admittance level controller according to claim 1, characterized in that: The control system includes a signal processing unit and an alarm module. The signal processing unit pre-stores a standard electrical signal when the coal drop pipe is not stuck. The alarm module is used to issue an early warning when it is determined that the coal drop pipe is stuck.

7. The device for detecting coal drop pipe jamming based on radio frequency admittance level controller according to claim 1, characterized in that: The detection device also includes a signal transmission module for transmitting the switch signal to the coal conveying program control system in a wired or wireless manner.

8. The device for detecting coal drop pipe jamming based on radio frequency admittance level controller according to claim 1, characterized in that: It includes multiple groups of receiving ends (1) and transmitting ends (2).

9. A method for detecting coal pipe jamming based on radio frequency admittance level controller, characterized in that: The coal drop pipe jam detection device based on the radio frequency admittance level controller according to any one of claims 1 to 8 is implemented, and the coal drop pipe jam detection method comprises the following steps: When the coal drop pipe body (3) is in a fully stretched or fully contracted state, an initial electrical signal is collected through the receiving end (1) and the transmitting end (2) of the radio frequency admittance module as a standard signal of a non-jamming state; When the coal drop pipe body (3) is in a non-fully stretched or fully contracted state, the radio frequency signal received by the receiving end (1) is monitored in real time to generate a real-time electrical signal; The real-time electrical signal is compared with the standard signal. If the conductivity of the real-time electrical signal exceeds a preset threshold, it is determined that the coal drop pipe body (3) is stuck, and an alarm is triggered.

10. The method for detecting coal drop pipe jamming based on radio frequency admittance level controller according to claim 9, characterized in that: The method for setting the preset threshold includes: Recording the conductivity of the coal drop pipe body (3) in a normal expansion and contraction state without any adhering materials as a reference value; According to the material properties and expansion and contraction frequency of the coal drop pipe body (3), 1.5-3 times of the reference value is set as the preset threshold value; The change in the conductivity coefficient is reflected by the attenuation amplitude of the frequency signal of the radio frequency admittance level controller.

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