Belt material moisture detection device and detection method

Abstract

The application provides a belt material moisture detection device. The device comprises a swing sampling mechanism, a driving assembly, a transmission connecting rod and a material bucket. The driving assembly drives the material bucket to reciprocate vertically above the conveying belt. The two sides of the wave-transparent rubber mat and the metal framework of the material bucket jointly form a microwave measurement cavity A with a fixed boundary. The microwave moisture detection assembly comprises a microwave detection device and a moisture meter. The microwave emission end and the microwave receiving end of the microwave detection device respectively face the wave-transparent rubber mat on both sides of the material bucket when the material bucket is in the detection position. The positioning assembly is correspondingly arranged at the detection position of the material bucket. In the initial state of 0, the material bucket, the microwave detection device and the positioning assembly are at the same horizontal height. The control system is electrically connected with the swing sampling mechanism and the microwave moisture detection assembly. The application can accurately and quickly detect the material moisture, providing technical support for the subsequent process.

Description

Technical Field

[0001] This invention relates to the field of industrial material moisture detection and automated control technology, specifically to a moisture detection device and method for conveyor belt materials. Background Technology

[0002] The moisture content of the sintering mixture is a key process parameter affecting the yield and quality of sintered ore. Excessive moisture content leads to decreased permeability of the material bed, while insufficient moisture content affects the granulation effect and thermal conductivity of the mixture. Therefore, accurate and timely online detection and control of the moisture content of the mixture is an important guarantee for the stable operation of the sintering process.

[0003] Currently, moisture detection of conveyor belt materials mainly employs techniques such as infrared spectroscopy, neutron spectroscopy, and microwave spectroscopy. However, each of these methods has significant limitations: infrared spectroscopy can only detect surface moisture and cannot reflect the true internal moisture content; while neutron spectroscopy offers high accuracy and representativeness, its application in the field is severely restricted by strict radiation safety regulations; and although microwave spectroscopy can penetrate the entire material for detection, the results are significantly affected by material density and composition. In particular, the constantly changing thickness and bulk density of the material on the conveyor belt become the biggest source of error for both microwave and capacitance spectroscopy, and existing compensation methods often introduce new variables, failing to fundamentally solve the problem.

[0004] Existing technologies already include solutions for applying microwave moisture detection to the online detection of sintered mixtures. For example, Chinese patent application CN120870183A discloses a new process for moisture detection in sintered mixtures. This solution involves installing a transversely rotating cutting and sampling device with a hopper in the middle of a conveyor belt for sintered mixtures. The sample is then transported to a dedicated small conveyor belt for moisture detection. Above this small conveyor belt, an iron removal device, a demagnetizing device, a scraping device, and a microwave moisture meter receiver are installed sequentially. The microwave moisture meter transmitter is installed below the working layer of the small conveyor belt, corresponding to the receiver across the belt. This solution removes iron, demagnetizes, and scrapes the sample on the small conveyor belt before performing microwave penetration detection. Furthermore, this solution includes a mechanism for periodic calibration using a drying method, comprising a microcomputer, a robotic arm, a robotic hand, and an electronic scale with a drying device.

[0005] While the aforementioned existing technical solutions have improved the automation level of moisture detection to some extent, they still have the following shortcomings: First, the material taken out of the hopper needs to be transferred to a dedicated small conveyor belt before testing. During the transfer, falling, and re-laying process, the material is prone to segregation, and the scraping device's leveling treatment of the material layer changes the original accumulation state of the material, making it difficult to accurately reflect the actual moisture distribution of the material on the belt. Second, the material is in motion on the dedicated small conveyor belt, and the microwave signal penetrates the dynamically flowing material layer. The detection stability under motion is far inferior to that under static conditions. Third, the system requires additional configuration of a dedicated small conveyor belt, iron removal device, demagnetizing device, scraping device, and a complex drying and calibration mechanism consisting of a robotic arm, robotic hand, sampling plate, and rotating brush. The equipment is numerous and the transmission links are complex, significantly increasing the number of failure points and maintenance workload under the harsh working conditions of high dust and high humidity at the sintering site. Fourth, the entire process from sampling, transfer, laying, leveling to testing completion is time-consuming, and the moisture feedback signal lags behind the actual working conditions.

[0006] To address these issues, we propose a novel device and method for detecting moisture content in conveyor belt materials, thereby resolving the aforementioned technical problems in existing technologies. Summary of the Invention

[0007] The purpose of this invention is to provide a technical field for industrial material moisture detection and automated control, so as to solve the technical problems existing in the prior art.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a belt conveyor material moisture detection device, comprising: The oscillating sampling mechanism, located directly above the conveyor belt, includes a drive assembly, a transmission link, and a material bucket. The drive assembly is mechanically connected to the material bucket via the transmission link, driving the material bucket to oscillate vertically up and down in a circular arc above the conveyor belt. Both opposite side walls of the material bucket are provided with microwave-transparent rubber pads, and the microwave-transparent rubber pads on both sides, together with the metal frame of the material bucket, form a microwave measurement cavity A with a fixed boundary. A microwave moisture detection assembly is installed on both sides of the conveyor belt and at a height higher than the conveyor belt. It includes a microwave detection device and a moisture meter. When the material bucket is in the detection position, the microwave transmitter and microwave receiver of the microwave detection device are respectively facing the microwave-transparent rubber pads on both sides of the material bucket. The moisture meter is signal-connected to the microwave detection device and is used to receive and calculate the real-time moisture value of the material sample. A positioning component is correspondingly set at the detection position of the material bucket to accurately stop the material bucket at the detection position; the detection position and the 0° standby position are located in the same spatial position, and in the initial state of 0°, the limiting structure of the material bucket, the microwave detection device and the positioning component are all at the same horizontal height; The control system is electrically connected to the swing sampling mechanism and the microwave moisture detection component.

[0009] Furthermore, the microwave-transparent pad is a polytetrafluoroethylene pad; the inner walls of the two microwave-transparent pads are arranged parallel to each other, so that a fixed microwave penetration path length is formed between the inner walls of the two microwave-transparent pads.

[0010] Furthermore, the cross-sectional area of ​​the microwave measuring cavity A is determined by multiplying the inner width of the material bucket by the effective height of the microwave-transparent rubber pad, and the processing tolerance of the area of ​​the microwave-transparent rubber pads on both sides is controlled within ±0.2mm.

[0011] Furthermore, the scooping width of the material bucket covers the main material distribution area in the transverse direction of the conveyor belt, so as to realize spatial integral sampling of the transverse material distribution on the conveyor belt; the scooping opening of the material bucket is oriented in the opposite direction to the transport direction of the conveyor belt; when the material bucket is at the lowest sampling position, a safety gap is left between its bottom lower edge and the upper surface of the conveyor belt; the front end of the material bucket is provided with a toothed structure along its opening edge for cutting into the material layer on the conveyor belt.

[0012] Furthermore, the total swing stroke angle of the material bucket, which swings vertically downward from the 0° standby position to the lowest sampling position to scoop up material and then swings upward back to the detection position, is 120° to 150°.

[0013] Furthermore, the drive assembly includes a motor and a reducer. The motor is a three-phase asynchronous motor, and the reducer is a worm gear reducer. The power output end of the three-phase asynchronous motor is connected to the input end of the worm gear reducer, and the power output shaft of the worm gear reducer drives the transmission connecting rod to reciprocate.

[0014] Furthermore, the positioning component includes a mechanical hard limit structure and a proximity switch. The mechanical hard limit structure is fixedly installed at the detection position and is used to stop and limit the swing stroke end of the material bucket. The proximity switch is installed at the detection position and is used to output a positioning signal when the material bucket reaches the detection position. The mechanical hard limit structure and the proximity switch constitute a dual positioning structure.

[0015] A method for detecting moisture content in conveyor belt materials based on the above-mentioned device includes the following steps: S1. Standby stage: When the conveyor belt is running continuously, the material bucket stays at the 0° standby position (i.e., the detection position) and waits for the sampling trigger signal from the control system. S2. Sampling and Transfer Stage: When the set sampling cycle is reached, the drive assembly starts and drives the material bucket to swing downward in an arc from the 0° standby position through the transmission linkage. During the downward swing, the toothed structure at the front end of the material bucket cuts into the material layer on the conveyor belt to scoop up the material sample. After the material bucket continues to move to the lowest sampling position, it swings upward in an arc back to the detection position with the material sample, and finally stops precisely through the positioning component. S3, Detection stage: The material bucket remains stationary at the detection position. The microwave detection device performs penetrating microwave detection on the material sample in the material bucket through the microwave-transparent rubber pad. The moisture meter calculates the real-time moisture value of the material sample based on the attenuation / phase change of the received microwave signal. S4. Reset Phase: After the detection is completed, the control system enters a delay countdown. After the countdown ends, the drive assembly drives the material bucket to swing downwards from the detection position, so that the residual material in the material bucket naturally falls back onto the conveyor belt under the action of gravity. Then the material bucket swings upwards to return to the 0° standby position, waiting for the next sampling cycle to be triggered.

[0016] Furthermore, an electric regulating valve for adjusting the water supply is installed downstream of the conveyor belt. The electric regulating valve is connected to the control system. The control system has a built-in PID calculation unit. After acquiring the real-time moisture value, it compares the real-time moisture value with the process target moisture value. If there is a deviation, it executes PID calculation and outputs a control signal to adjust the opening of the downstream electric regulating valve to achieve closed-loop control of the water supply.

[0017] Compared with existing technologies, the above technical solution has the following advantages: 1. The material bucket itself also serves as a microwave measurement cavity with fixed boundaries. After sampling, static penetration testing can be performed directly without transferring the material, thus avoiding the influence of material segregation and changes in the stacking state on the test results. The microwave penetration path length and the cross-sectional area of ​​the measurement cavity are both constant values, which fundamentally eliminates the measurement error introduced by the traditional microwave method due to changes in the thickness of the material layer. 2. The material bucket's scooping width covers the main material distribution area in the transverse direction of the conveyor belt. Each scoop is a spatial integral sampling, which effectively solves the problem of uneven transverse moisture distribution caused by belt misalignment and particle segregation in fixed-point detection. The detection lag time is greatly shortened, and the cycle from sampling to completing closed-loop adjustment is significantly shortened, fully meeting the real-time control requirements. 3. The device is simple and reliable. The pure mechanical transmission chain is not sensitive to dust and does not require an air source or hydraulic station. With modular design, it can achieve maintenance without downtime. The system has a low failure rate and the total life cycle maintenance cost is significantly reduced. In summary, this invention enables precise and rapid detection of material moisture through active quantitative sampling, static detection, full-layer penetration, stable wave transmission via adhesive pads, and precise mechanical positioning, providing technical support for subsequent processes. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a flowchart of the signal processing and closed-loop control of the present invention; Figure 3 This is a flowchart of the mechanical action and time cycle control of the present invention.

[0020] Explanation of reference numerals in the attached drawings: 1. Motor; 2. Reducer; 3. Microwave detection device; 4. Material bucket; 5. Wave-transparent rubber pad; 6. Moisture meter; 7. Transmission link; 8. Conveyor belt; A. Microwave measuring cavity. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0022] To address the problems existing in the prior art, the present invention provides a device and method for detecting moisture content in conveyor belt materials. The present invention will be described in detail below with reference to the accompanying drawings.

[0023] See Figures 1-3 As shown, the present invention provides a belt material moisture detection device, which mainly includes a swing sampling mechanism, a microwave moisture detection component, a positioning component and a control system.

[0024] The swing sampling mechanism is positioned directly above the conveyor belt 8 and includes a drive assembly, a transmission link 7, and a material bucket 4. The drive assembly includes a motor 1 and a reducer 2, with the power output end of the motor 1 connected to the input end of the reducer 2. Preferably, the motor 1 is a 1.5kW three-phase asynchronous motor with a rated output speed of 1450 r / min; the reducer 2 is a worm gear reducer with a reduction ratio set to 60, which can reduce the high output speed of the motor 1 to approximately 14 r / min while increasing the output torque to approximately 60 times the rated torque of the motor 1, thereby providing sufficient driving torque to overcome the cutting resistance when the bucket cuts into the material flow. The power output shaft of the reducer 2 is connected to one end of the transmission link 7, and the other end of the transmission link 7 is connected to the material bucket 4. The drive assembly drives the material bucket 4 to reciprocate in a circular arc above the conveyor belt 8 in a vertical direction via the transmission link 7, allowing the material bucket 4 to swing downwards from the 0° standby position to cut into the conveyor belt material flow, scoop up the material, and then swing upwards back to the detection position. Preferably, the total swing stroke angle of the material bucket 4, which swings downward from the 0° standby position to the lowest sampling position and then swings upward back to the detection position, is set to 120° to 150°.

[0025] Specifically, both sides of the material bucket 4 are provided with microwave-transparent rubber pads 5, which, together with the metal frame of the material bucket 4, form a microwave measurement cavity A with fixed boundaries. Preferably, the microwave-transparent rubber pads 5 are made of polytetrafluoroethylene (PTFE), which has an extremely low dielectric constant (εᵣ = 2.0–2.2) and an extremely low loss tangent (tanδ = 2 × 10⁻⁻⁻⁴). 4 The material is almost transparent to microwave signals and has high and low temperature resistance (-180℃ to +260℃) and corrosion resistance, making it suitable for harsh industrial conditions. The inner walls of the two microwave-transparent pads 5 are arranged parallel to each other, forming a fixed microwave penetration path length between them, preferably 150mm. The cross-sectional area of ​​the microwave measuring cavity A is determined by multiplying the inner width of the material bucket 4 by the effective height of the microwave-transparent pads 5. Preferably, the inner width of the material bucket 4 is 30cm, and the effective height of the microwave-transparent pads 5 is 20cm, resulting in a measuring cavity cross-sectional area of ​​approximately 0.060m². To ensure that the areas of the two microwave-transparent pads 5 are consistent and their boundaries are absolutely fixed, the machining tolerance of the distance between the inner walls of the two microwave-transparent pads 5 is strictly controlled within ±0.2mm, thereby ensuring that the received signal after penetrating the material layer exhibits a highly stable characteristic in the time domain.

[0026] Furthermore, the scooping width of the material bucket 4 covers the main material distribution area in the transverse direction of the conveyor belt 8, preferably 30 cm, and each scooping action is a spatial integral sampling of the material within this width range. The scooping opening of the material bucket 4 faces the opposite direction of the conveyor belt 8 so as to actively intercept the material flow when swinging in. At the lowest sampling position, a safety gap, preferably 20 mm, is left between its bottom lower edge and the upper surface of the conveyor belt 8 to avoid direct contact between the bucket and the belt surface. The front end of the material bucket 4 is provided with a toothed structure along its opening edge for crushing and grabbing the material layer on the conveyor belt 8 during the swinging infeed. In addition, the swinging sampling mechanism adopts a modular design and is fixedly connected to the frame through detachable connectors. When maintenance is required, it can be completely disassembled and removed without affecting the normal operation of the conveyor belt 8.

[0027] It should be specifically noted that the microwave moisture detection assembly is located on both sides of the conveyor belt 8 and is higher than the conveyor belt 8. It includes a microwave detection device 3 and a moisture meter 6. The microwave detection device 3 has a microwave transmitter and a microwave receiver, respectively located on both sides of the conveyor belt 8. When the material bucket 4 is in the detection position, the microwave transmitter and microwave receiver are directly facing the microwave-transparent rubber pads 5 on both sides of the material bucket 4. The moisture meter 6 is signal-connected to the microwave detection device 3, used to receive electrical signals and calculate the real-time moisture value of the material sample based on the attenuation and phase change of the microwave signal.

[0028] It should be specifically noted that the positioning components are correspondingly installed at the detection position of the material bucket 4, including a mechanical hard limit structure and a proximity switch. The mechanical hard limit structure is fixedly installed at the detection position to stop and limit the swing stroke of the material bucket 4; the proximity switch is used to output a positioning signal when the material bucket 4 reaches the detection position; the two constitute a dual positioning structure to ensure that the material bucket 4 can accurately stop at the detection position every time. The detection position and the 0° standby position are located in the same spatial position. In the initial state of 0°, the material bucket 4, the microwave detection device 3, and the limiting structure of the positioning components are all at the same horizontal height.

[0029] It should be specifically noted that the control system is electrically connected to the swing sampling mechanism and the microwave moisture detection component. Downstream of the conveyor belt 8, an electrically operated regulating valve is installed to adjust the water supply. This valve is connected to the control system via a signal connection. The control system has a built-in PID calculation unit. After acquiring the real-time moisture value, it compares it with the preset process target moisture value. If a deviation exists, the PID calculation is executed, and a control signal is output to adjust the opening of the electrically operated regulating valve, thereby achieving closed-loop control of the water supply.

[0030] The present invention also provides a method for detecting moisture content in conveyor belt materials based on the above-mentioned device, specifically including the following steps: S1. Standby stage: When the conveyor belt 8 is running continuously, the material bucket 4 stays at the 0° standby position (i.e., the detection position) and waits for the sampling trigger signal issued by the control system.

[0031] S2. Sampling and Transfer Stage: When the set sampling cycle is reached, the drive assembly starts and drives the material bucket 4 to swing downward in an arc from the 0° standby position through the transmission link 7. During the downward swing, the toothed structure at the front end of the material bucket 4 cuts into the material layer on the conveyor belt 8 to scoop up the material sample. After the material bucket 4 continues to move to the lowest sampling position, it swings upward in an arc to return to the detection position, and finally stops precisely through the positioning component.

[0032] In step S2, the sampling period can be selected as 60 minutes. Of course, the sampling period can be adjusted within the range of 30 to 120 minutes according to the actual working conditions.

[0033] S3, Detection Stage: The material bucket 4 remains stationary at the detection position. The microwave detection device 3 performs penetrating microwave detection on the material sample inside the material bucket 4 through the microwave-transparent pad 5. Since the geometric boundaries and path length of the microwave measuring cavity A are strictly fixed, the microwave signal is stable. The moisture meter 6 calculates the real-time moisture value of the material sample based on the attenuation / phase change of the received microwave signal. Subsequently, the PID calculation unit built into the control system compares the real-time moisture value with the preset process target moisture value. If there is a deviation, the PID calculation is executed and a control signal is directly output to the downstream electric regulating valve. The closed-loop control of the water addition is achieved by adjusting the opening of the electric regulating valve.

[0034] S4. Reset Phase: After the detection is completed, the control system enters a delay countdown. After the countdown ends, the drive assembly drives the material bucket 4 to swing downwards from the detection position, so that the residual material in the material bucket 4 naturally falls back to the conveyor belt 8 under the action of gravity. Then the material bucket 4 swings upwards to return to the 0° standby position, waiting for the next sampling cycle to be triggered.

[0035] The delay countdown in step S4 can be set to 90 seconds.

[0036] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element 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 invention.

[0037] The above description is only used to illustrate the technical solution of the present invention and is not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention, as long as they do not depart from the spirit and scope of the technical solution of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A device for detecting moisture content in conveyor belt materials, characterized in that, include: The swing sampling mechanism is located directly above the conveyor belt (8) and includes a drive assembly, a transmission link (7) and a material bucket (4). The drive assembly is mechanically connected to the material bucket (4) through the transmission link (7) and drives the material bucket (4) to swing back and forth in a circular arc above the conveyor belt (8) in the vertical direction. Wave-transparent rubber pads (5) are provided on the opposite side walls of the material bucket (4). The wave-transparent rubber pads (5) on both sides and the metal frame of the material bucket (4) together form a microwave measurement cavity A with a fixed boundary. A microwave moisture detection assembly is installed on both sides of the conveyor belt (8) and is higher than the conveyor belt (8). It includes a microwave detection device (3) and a moisture meter (6). The microwave transmitting end and microwave receiving end of the microwave detection device (3) are respectively facing the microwave-transparent rubber pads (5) on both sides of the material bucket (4) when the material bucket (4) is in the detection position. The moisture meter (6) is connected to the microwave detection device (3) for receiving and calculating the real-time moisture value of the material sample. The positioning component is set at the detection position of the material bucket (4) to accurately stop the material bucket (4) at the detection position; the detection position and the 0° standby position are located in the same space. In the initial state of 0°, the limiting structure of the material bucket (4), the microwave detection device (3) and the positioning component are all at the same horizontal height. The control system is electrically connected to the swing sampling mechanism and the microwave moisture detection component.

2. The belt conveyor material moisture detection device according to claim 1, characterized in that, The microwave-transparent pad (5) is a polytetrafluoroethylene pad; the inner walls of the microwave-transparent pads (5) on both sides are arranged in parallel opposite directions, so that a fixed microwave penetration path length is formed between the inner walls of the two microwave-transparent pads (5).

3. The belt conveyor material moisture detection device according to claim 1, characterized in that, The cross-sectional area of ​​the microwave measuring cavity A is determined by multiplying the inner width of the material bucket (4) by the effective height of the microwave-transparent rubber pad (5), and the area processing tolerance of the microwave-transparent rubber pad (5) on both sides is controlled within ±0.2mm.

4. The belt conveyor material moisture detection device according to claim 1, characterized in that, The scooping width of the material bucket (4) covers the main material distribution area in the transverse direction of the conveyor belt (8) to achieve spatial integral sampling of the transverse material distribution on the conveyor belt (8); the scooping opening of the material bucket (4) is oriented opposite to the transport direction of the conveyor belt (8); when the material bucket (4) is at the lowest sampling position, a safety gap is left between its bottom lower edge and the upper surface of the conveyor belt (8); the front end of the material bucket (4) is provided with a toothed structure along its opening edge for cutting into the material layer on the conveyor belt (8).

5. The belt conveyor material moisture detection device according to claim 1, characterized in that, The material bucket (4) swings vertically downward from the 0° standby position to the lowest sampling position to scoop up the material, and then swings upward back to the detection position. The total swing stroke angle is 120° to 150°.

6. The belt conveyor material moisture detection device according to claim 1, characterized in that, The drive assembly includes a motor (1) and a reducer (2). The motor (1) is a three-phase asynchronous motor, and the reducer (2) is a worm gear reducer. The power output end of the three-phase asynchronous motor is connected to the input end of the worm gear reducer, and the power output shaft of the worm gear reducer drives the transmission connecting rod (7) to reciprocate.

7. The belt conveyor material moisture detection device according to claim 1, characterized in that, The positioning component includes a mechanical hard limit structure and a proximity switch. The mechanical hard limit structure is fixedly set at the detection position and is used to stop and limit the swing stroke end of the material bucket (4). The proximity switch is set at the detection position and is used to output a positioning signal when the material bucket (4) reaches the detection position. The mechanical hard limit structure and the proximity switch constitute a dual positioning structure.

8. A method for detecting moisture content in conveyor belt materials based on the device according to any one of claims 1-7, characterized in that, Includes the following steps: S1, Standby stage: When the conveyor belt (8) is running continuously, the material bucket (4) stays at the 0° standby position (i.e., the detection position) and waits for the sampling trigger signal issued by the control system; S2, Sampling and Transfer Stage: When the set sampling cycle is reached, the drive assembly starts and drives the material bucket (4) to swing downward in an arc from the 0° standby position through the transmission link (7); during the downward swing, the toothed structure at the front end of the material bucket (4) cuts into the material layer on the conveyor belt (8) to scoop up the material sample; after the material bucket (4) continues to move to the lowest sampling position, it swings upward in an arc to return to the detection position, and finally stops precisely through the positioning component; S3, Detection stage: The material bucket (4) remains stationary at the detection position. The microwave detection device (3) performs penetrating microwave detection on the material sample in the material bucket (4) through the microwave-transparent rubber pad (5). The moisture meter (6) calculates the real-time moisture value of the material sample based on the attenuation / phase change of the received microwave signal. S4. Reset phase: After the detection is completed, the control system enters a delay waiting countdown; after the countdown ends, the drive assembly drives the material bucket (4) to swing downwards from the detection position, so that the residual material in the material bucket (4) naturally falls back to the conveyor belt (8) under the action of gravity. Then the material bucket (4) swings upwards again to return to the 0° standby position, waiting for the next sampling cycle to be triggered.

9. The method for detecting moisture content in conveyor belt materials according to claim 8, characterized in that, Downstream of the conveyor belt (8) is an electric regulating valve for adjusting the amount of water added. The electric regulating valve is connected to the control system. The control system has a built-in PID calculation unit. After obtaining the real-time moisture value, the real-time moisture value is compared with the process target moisture value. If there is a deviation, the PID calculation is executed and the control signal is output to adjust the opening of the downstream electric regulating valve so as to realize the closed-loop control of the amount of water added.

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