Intelligent driving anti-sticking conveying system for rare earth powder

Abstract

The utility model relates to the technical field of conveying equipment, in particular to an intelligent driving anti-sticking conveying system for rare earth powder, which comprises a feeding device and a screw conveyer, piezoelectric films are respectively covered on the surfaces of a central shaft, a screw blade and the inner wall of a casing of the screw conveyer, and the piezoelectric films are connected with the feeding device. The accumulation and adhesion conditions of rare earth materials are sensed in real time through the piezoelectric film, mechanical stress is converted into voltage signals through the direct piezoelectric effect, the valve opening degree is dynamically adjusted to maintain the stable conveying amount, and the situation that the electrolysis efficiency is reduced due to excessive accumulation of rare earth in an electrolysis furnace is prevented; meanwhile, the piezoelectric films of the independent units are driven to vibrate through the inverse piezoelectric effect, rare earth materials adhering to the interior of the spiral conveyor are automatically cleaned, it is guaranteed that the conveying process is smooth, and the service life of equipment is prolonged. According to the rare earth conveying device, automation, precision and high efficiency of rare earth conveying are achieved, production efficiency is remarkably improved, manual intervention and maintenance cost are reduced, and the defects of existing equipment are overcome.

Description

Technical Field

[0001] This utility model relates to the field of conveying equipment technology, specifically to a rare earth powder intelligent drive anti-sticking conveying system. Background Technology

[0002] Rare earth molten salt electrolysis is a process that uses direct current to induce chemical changes in an electrolytic cell. Through a redox reaction between the cathode and anode, rare earth metal ions gain electrons at the cathode and are reduced to rare earth metals. This process is typically carried out at a high temperature of 1000-1200℃ to ensure that the rare earth fluoride melt is fully electrolyzed. Rare earth molten salt electrolysis equipment mainly consists of two parts: a conveying device and an electrolytic furnace. The conveying device is responsible for continuously and stably feeding the raw rare earth material into the electrolytic furnace, which is the core equipment for achieving the reduction of rare earth metals.

[0003] Traditional rare earth molten salt electrolysis equipment typically employs an intermittent feeding method, where a certain amount of raw rare earth material is added to the electrolysis furnace every five minutes. While this method is simple and easy to implement, it also has significant drawbacks. First, intermittent feeding causes the electrolysis furnace to receive a large amount of rare earth raw material in a short period, resulting in excessive accumulation of rare earth. Due to the limited reaction rate within the electrolysis furnace, the rapid addition of large amounts of rare earth prevents the electrolysis reaction from proceeding sufficiently, thus reducing the efficiency of rare earth molten salt electrolysis. Second, excessive accumulation of rare earth also leads to uneven temperature and current distribution within the electrolysis furnace, further affecting the stability of the electrolysis process and the quality of the rare earth metal produced.

[0004] Furthermore, during the traditional feeding process, rare earth raw materials, due to their inherent viscosity, tend to adhere inside the conveyor. This adhesion not only makes the conveying process difficult and reduces efficiency but also increases wear on the screw blades, shortening the conveyor's lifespan. Over time, the adhered rare earth material gradually accumulates, leading to increased conveyor resistance and potentially causing equipment failure, increasing maintenance costs and production downtime. Utility Model Content

[0005] The purpose of this utility model is to provide an intelligent driven anti-sticking conveying system for rare earth powder, which aims to solve the technical problem that existing rare earth materials are prone to accumulation due to the process and tend to adhere to the inside of the screw conveyor during the conveying process, affecting the smoothness of the conveying process and the service life of the equipment.

[0006] To achieve the above objectives, this utility model provides an intelligent driven anti-sticking conveying system for rare earth powder, including a feeding device and a screw conveyor, wherein the feeding device and the screw conveyor are connected in sequence.

[0007] The feeding device includes a split hopper, an upper valve, and a lower valve. The upper valve divides the split hopper into upper and lower parts, and the lower valve is located between the split hopper and the screw conveyor.

[0008] The screw conveyor includes a motor, a central shaft, helical blades, and a housing. The surfaces of the central shaft, helical blades, and the inner wall of the housing are all covered with a piezoelectric film, which is composed of multiple independent units spliced ​​together.

[0009] The piezoelectric film independent unit on the central axis is parallelogram in shape, while the piezoelectric film independent unit on the inner wall of the housing is rectangular in shape.

[0010] The shape of the piezoelectric film unit on the helical blade is determined by the side cross-sectional shape of the helical blade, dividing the ring into six parts to cover different areas on the side of each helical blade.

[0011] In each piezoelectric thin film unit, the two ends of the piezoelectric thin film are fixed, while there is a certain gap between the piezoelectric thin film and the surface in the middle.

[0012] This invention provides an intelligent driven anti-sticking conveying system for rare earth powder. The system includes a feeding device and a screw conveyor. Piezoelectric films are coated on the central shaft, screw blades, and inner wall of the screw conveyor. These films sense the accumulation and adhesion of rare earth materials in real time. Using the positive piezoelectric effect, mechanical stress is converted into a voltage signal, dynamically adjusting the valve opening to maintain a stable conveying volume and prevent excessive rare earth accumulation in the electrolysis furnace, which would reduce electrolysis efficiency. Simultaneously, the inverse piezoelectric effect drives the vibration of independent piezoelectric film units, automatically cleaning the rare earth materials adhering to the inside of the screw conveyor, ensuring smooth conveying and extending equipment lifespan. This invention achieves automation, precision, and high efficiency in rare earth conveying, significantly improving production efficiency, reducing manual intervention and maintenance costs, providing reliable technical support for rare earth molten salt electrolysis processes, and compensating for the shortcomings of existing equipment. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the structure of a rare earth powder intelligent drive anti-sticking conveying system according to this utility model.

[0015] Figure 2 This is a schematic diagram of the internal piezoelectric film arrangement of a rare earth powder intelligent drive anti-sticking conveying system according to this utility model.

[0016] Figure 3 This is a side view schematic diagram of a single spiral blade of a rare earth powder intelligent drive anti-sticking conveying system according to this utility model.

[0017] Figure 4 This is a schematic diagram of the vibration of a single piezoelectric thin film according to this utility model.

[0018] Figure 5 This is a schematic diagram illustrating the anti-sticking function of an intelligent driven anti-sticking conveying system for rare earth powders according to this utility model.

[0019] 1-Separate hopper, 2-Upper valve, 3-Lower valve, 4-Motor, 5-Central shaft, 6-Helical blade, 7-Casing. Detailed Implementation

[0020] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0021] Please see Figure 1 and Figure 2 This utility model provides an intelligent driven anti-sticking conveying system for rare earth powder, including a feeding device and a screw conveyor, wherein the feeding device and the screw conveyor are connected in sequence.

[0022] The feeding device includes a split silo 1, an upper valve 2 and a lower valve 3. The upper valve 2 divides the split silo 1 into upper and lower parts, and the lower valve 3 is located between the split silo and the screw conveyor.

[0023] The screw conveyor includes a motor 4, a central shaft 5, a screw blade 6, and a housing 7. The surfaces of the central shaft 5, the screw blade 6, and the inner wall of the housing 7 are all covered with a piezoelectric film, which is composed of multiple independent units spliced ​​together.

[0024] In this embodiment, the upper part of the split-type hopper 1 is the raw material accumulation area, and the lower part is the pre-feeding area. The electrodes of the piezoelectric film are introduced into the wires inside the central shaft 5 through the inside of the spiral blades 6, while the piezoelectric film on the inner wall of the conveyor housing 7 is directly introduced into the wires of the housing 7.

[0025] Furthermore, the piezoelectric film individual units on the central shaft 5 are parallelograms in shape, while the piezoelectric film individual units on the inner wall of the housing 7 are rectangular. The piezoelectric films on the central shaft 5 are interconnected parallelograms, and the piezoelectric films on the inner wall of the conveyor housing 7 are arranged in interconnected rectangles. Both arrangements utilize multiple individual units to improve control precision.

[0026] Please see Figure 3 The shape of the piezoelectric film unit on the helical blade is determined by the side cross-sectional shape of the helical blade, dividing the ring into six parts to cover different areas on the side of each helical blade.

[0027] Specifically, such as Figure 4 As shown, in each independent piezoelectric film unit, the two ends of the piezoelectric film are fixed, while there is a certain gap between the piezoelectric film and the surface in the middle. When a voltage is applied to the piezoelectric film, it will generate continuous up-and-down vibration, thereby achieving the purpose of shaking off rare earth elements.

[0028] This utility model relates to an intelligent drive anti-sticking conveying control method for rare earth powders, comprising the following steps:

[0029] Step 1: Control the upper valve to stockpile rare earth raw materials;

[0030] Step 2: Upon receiving the feeding signal or the piezoelectric feedback value from the previous feeding, adjust the opening of the lower valve and open the upper valve to feed the material;

[0031] Step 3: Start the motor to enter the conveying stage;

[0032] Step 4: Real-time acquisition of voltage signals from each independent unit of the piezoelectric film. When the detected voltage in the spiral blade area increases, the valve opening is adjusted using a PID algorithm to maintain the conveying volume within ±2% of the set value.

[0033] Step 5: After completing a single delivery, switch to anti-stick detection mode;

[0034] Step 6: After the anti-sticking test is completed, complete the feeding or return to Step 1.

[0035] During the execution of the anti-adhesion detection mode, there are two working modes: full unit vibration and partial unit vibration. In the full unit vibration mode, all independent piezoelectric film units will vibrate continuously during transportation to prevent rare earth adhesion. In the partial unit vibration mode, the control module outputs an alternating voltage to the independent piezoelectric film units with attached rare earth to shake off the adhered rare earth.

[0036] Different working modes have the following effects:

[0037] 1. Full Unit Vibration Mode: In this mode, when delivery begins, the control module directly outputs an alternating voltage, causing all piezoelectric film units to vibrate continuously, preventing rare earth adhesion. The advantage of full unit vibration mode is that it eliminates the need for detection modules and some control modules, reducing costs.

[0038] 2. Local Unit Vibration Mode: This refers to the operational mode mentioned in the technical solution. After the conveying process ends, the system enters the detection phase. The control module then outputs an alternating voltage to the piezoelectric film unit with attached rare earth elements, causing the adhering rare earth to be shaken off. The advantages of local unit vibration mode are energy saving and precise control.

[0039] The process of conveying and cleaning integrated materials consists of the following two stages:

[0040] 1. Conveying Stage: The amount of rare earth material conveyed each time is fed into the pre-feeding area through the upper valve at the raw material accumulation point. The lower valve at the pre-feeding area controls the opening size of the rare earth material into the screw conveyor through a feedback mechanism. Specific feedback control method: When the rare earth material enters the screw conveyor, it exerts pressure and friction on the piezoelectric film covering the screw blades during propulsion. These forces cause the piezoelectric film to deform, thereby generating a voltage. According to the piezoelectric effect, the more rare earth material accumulates, the greater the pressure applied to the piezoelectric film. Therefore, the valve opening decreases as the voltage increases, allowing the propulsion equipment to maintain a stable conveying volume.

[0041] 2. Rare Earth Adhesion Prevention Stage: After each conveying cycle, the system enters a detection mode. The system consists of a voltage detection module, a control module, and a power supply module. The voltage detection module collects voltage signals generated by the piezoelectric film on each unit of the spiral blades, central shaft, and inner wall of the conveyor housing in real time. When rare earth adheres to the piezoelectric film, it deforms and generates voltage. If the voltage received by the control module exceeds a preset threshold, it controls the power supply module to output alternating voltage, driving the piezoelectric film of that unit to vibrate and shake off the rare earth. The system's detection mode detects the voltage of each independent unit. Units with voltage signals exceeding the preset threshold receive the alternating voltage output by the power supply module, while units with voltage signals below the preset threshold do not receive voltage. During vibration, the detection module continuously monitors the voltage signal of the piezoelectric film. When the piezoelectric film voltage falls below the preset threshold, it is determined that the adhered rare earth has been cleaned up. The control module stops outputting alternating voltage and simultaneously sends a signal to the upper valve at the raw material accumulation point to initiate a new round of feeding.

[0042] For information on the form of anti-stick action, please refer to [link / reference]. Figure 5 , Figure 5The diagram shows a section of the screw conveyor taken at the end of one conveying cycle. Each area, from 1 to 32, is an independent piezoelectric film unit. As shown in the diagram, rare earth elements adhere to areas 1, 2, 5, and 6 on the inner wall of the screw conveyor and areas 13, 17, 18, 21, and 22 on the central shaft. At this point, the system enters detection mode. Due to the rare earth adhesion, pressure is generated on the piezoelectric film areas on the inner wall and central shaft. Because of the piezoelectric effect, the piezoelectric film generates a voltage. If the voltage received by the control module exceeds a preset threshold, it controls the power module to output an alternating voltage, driving the piezoelectric films 1, 2, 5, 6, 13, 17, 18, 21, and 22 to vibrate, shaking off the rare earth elements. During this process, other piezoelectric film units are not driven, achieving precise control.

[0043] To clearly demonstrate the control role of piezoelectric thin films in rare earth molten salt electrolysis feeding devices, this invention also conducts a theoretical analysis based on the theoretical foundation of the piezoelectric effect and its specific application in the system. The detailed analysis process is as follows:

[0044] 1. Theoretical basis of piezoelectric effect

[0045] The piezoelectric effect is divided into the direct piezoelectric effect and the inverse piezoelectric effect, and their mathematical descriptions are as follows:

[0046] 1.1 Positive piezoelectric effect

[0047] When a piezoelectric thin film is subjected to mechanical stress T, it will generate a charge density D (or voltage V), and the relationship is as follows:

[0048] D=d·T (1)

[0049] in:

[0050] D is the charge density (unit: C / m³). 2 );

[0051] d is the piezoelectric constant (unit: C / N), which represents the material's ability to convert mechanical energy into electrical energy;

[0052] T is the mechanical stress (unit: N / m). 2 ).

[0053] 1.2 Inverse piezoelectric effect

[0054] When an electric field E is applied to a piezoelectric thin film, a mechanical strain S is generated, and the relationship is as follows:

[0055] S=d·E (2)

[0056] in:

[0057] S is mechanical strain (unit: m / m);

[0058] E is the electric field strength (unit: V / m).

[0059] 2. The role of piezoelectric films in valve regulation

[0060] 2.1 Relationship between rare earth accumulation and pressure

[0061] In a screw conveyor, the accumulation amount m of rare earth material will exert a pressure T on the screw blades:

[0062] According to the piezoelectric effect, the voltage signal V generated by the piezoelectric film is proportional to the pressure T:

[0063] V=k·T=k'·m (3)

[0064] Where k and k' are proportionality constants.

[0065] 2.2 Adjustment of valve opening

[0066] The relationship between valve opening θ and voltage signal V is as follows:

[0067] θ=θ max -k n ·V (4)

[0068] Where: θ max This represents the maximum valve opening.

[0069] K n This is the adjustment coefficient.

[0070] When the amount of rare earth accumulation m increases, the voltage signal V increases, the valve opening θ decreases, thereby reducing the amount of rare earth entering.

[0071] 2.3 Controlling effect

[0072] By monitoring the rare earth accumulation in real time with a piezoelectric thin film and dynamically adjusting the valve opening, the rare earth material is ensured to enter the electrolysis furnace at a stable flow rate.

[0073] This closed-loop control method avoids excessive accumulation of rare earth elements in the electrolytic furnace, thus improving electrolysis efficiency.

[0074] 3. The role of piezoelectric films in preventing rare earth adhesion

[0075] 3.1 Relationship between rare earth adhesion and pressure

[0076] When rare earth materials adhere to the screw conveyor, they apply pressure T to the piezoelectric film:

[0077] According to the positive piezoelectric effect, the piezoelectric thin film generates a voltage signal V:

[0078] V=k·T (5)

[0079] 3.2 Vibration Cleaning Mechanism

[0080] When the independent unit voltage signal V is detected to exceed a preset threshold, the system applies an alternating voltage Vac to the piezoelectric film:

[0081] V ac =V0·sin(2πft) (6)

[0082] in:

[0083] V0 is the amplitude of the alternating voltage;

[0084] f is the vibration frequency.

[0085] According to the inverse piezoelectric effect, the piezoelectric thin film generates mechanical vibration SS:

[0086]

[0087] Where t is the thickness of the piezoelectric film.

[0088] 3.3 Controlling effect

[0089] The vibration is transmitted to the piezoelectric thin film unit, shaking off the adhered rare earth material.

[0090] During the vibration process, the system continuously monitors the voltage signal V of the independent unit. When V is lower than the preset threshold, the vibration stops and the cleaning is completed.

[0091] Specifically, this utility model also provides specific embodiments for further explanation:

[0092] 1. System Structure Composition of the Implementation Example

[0093] This system comprises two core components: a feeding device and a screw conveyor. The feeding device consists of a split-type hopper and a valve mechanism: the upper part of the hopper is a raw material storage bin, and the lower part is a pre-feeding bin, connected by a pneumatic upper valve; the bottom of the pre-feeding bin has an electrically adjustable lower valve, whose opening degree can be continuously adjusted within the range of 0-100%. The screw conveyor includes an explosion-proof motor (7.5kW power), a central shaft (150mm diameter), and screw blades (200mm pitch). The central shaft, screw blades, and the inner wall surface of the conveyor casing are all coated with a piezoelectric film.

[0094] 2. Piezoelectric film arrangement scheme

[0095] The helical blade surface adopts a six-segment layout: each helical unit is radially divided into six independent piezoelectric units, using a 0.2mm thick PVDF piezoelectric film. Electrode leads are connected to the central shaft wires via internal channels within the blades. The central shaft surface is fitted with tightly connected rectangular piezoelectric film units (50×200mm in size), and corresponding piezoelectric film units are installed on the inner wall of the conveyor housing, mirroring the central shaft surface. All piezoelectric units are independently addressable via flexible wiring, achieving a control accuracy of ±5mm. 2 .

[0096] 3. Intelligent conveying control process

[0097] (1) The valve is initially open and then closed after the raw material falls into the pre-feeding bin;

[0098] (2) The lower valve adjusts its initial opening based on the piezoelectric feedback value from the previous delivery;

[0099] (3) Start the motor (speed adjustable from 30-60 rpm) and the material enters the conveying section;

[0100] (4) Real-time acquisition of voltage signals of each piezoelectric unit. When the detected voltage in the spiral blade area increases, the valve opening is adjusted by PID algorithm (adjustment rate ≤ 5% / s) to maintain the conveying capacity within the range of ±2% of the set value.

[0101] (5) After a single delivery is completed, the system automatically switches to the anti-stick detection mode.

[0102] 4. Self-cleaning and non-stick control methods

[0103] (1) After shutdown, start the self-test program to scan the residual voltage of all piezoelectric units: set the cleaning threshold voltage, and mark the units with voltage values ​​greater than the set threshold as adhesion areas.

[0104] (2) Apply alternating voltage to the marked area for 3-5 cycles;

[0105] (3) Monitor the voltage decay curve during vibration in real time, and determine that the cleaning is qualified when the voltage is less than the predetermined threshold.

[0106] (4) Complete cleaning and trigger the upper valve opening command to complete system reset.

[0107] 5. Power supply and control system

[0108] It adopts a three-level inverter power supply module with an adjustable output voltage range of ±150V and a maximum output current of 2A. The control module integrates an FPGA high-speed signal processor with a sampling frequency of 10kHz and is equipped with an industrial Ethernet communication interface. Abnormal state protection mechanisms include: piezoelectric unit overload protection (power-off triggered when current > 1.5A), valve jamming alarm (position feedback deviation > 3%), and vibration timeout protection (automatic termination when single cleaning time > 120s).

[0109] In summary, this utility model has the following advantages:

[0110] I. Its role in transportation:

[0111] 1. Real-time monitoring of rare earth accumulation

[0112] Piezoelectric films can sense the accumulation of rare earth materials on a screw conveyor in real time. The more rare earth materials accumulate, the greater the pressure and friction on the piezoelectric film, and the stronger the generated voltage signal. By monitoring changes in the voltage signal, the conveying status of the rare earth materials can be indirectly reflected.

[0113] 2. Automatically adjust valve opening

[0114] The output voltage signal of the piezoelectric film is directly used to control the valve opening, achieving automated regulation. A larger voltage signal results in a smaller valve opening, reducing the amount of rare earth elements entering the valve; conversely, a smaller voltage signal results in a larger valve opening, increasing the amount of rare earth elements entering the valve. This closed-loop control method requires no manual intervention, improving the system's automation level.

[0115] 3. Maintain a stable delivery volume

[0116] Dynamic adjustment of valve opening ensures a stable flow rate of rare earth materials into the electrolytic furnace. This prevents excessive accumulation of rare earth in the screw conveyor and avoids fluctuations in the conveying volume. It also ensures the amount of rare earth material in the electrolytic furnace remains within the optimal range, improving electrolysis efficiency. Stable conveying volume prevents excessive accumulation of rare earth material in the electrolytic furnace, which would reduce the electrolysis rate and affect production efficiency. Real-time monitoring by the piezoelectric film and valve adjustment effectively avoid this problem.

[0117] 4. Reduce manual intervention and maintenance costs

[0118] The application of piezoelectric films enables automated system operation, reducing reliance on manual monitoring and adjustment. It eliminates the need for real-time manual valve adjustments, reducing operator workload. It also reduces equipment malfunctions or production accidents caused by human error. By stabilizing conveying volume and preventing material accumulation, it reduces mechanical wear and overload risks. Screw conveyors and electrolytic furnaces operate more smoothly, reducing failure rates. Furthermore, the piezoelectric film itself possesses high durability, enabling long-term stable operation.

[0119] II. Its effect on preventing rare earth adhesion:

[0120] 1. Real-time monitoring and automatic cleaning

[0121] The piezoelectric film can monitor the rare earth adhesion on the screw conveyor in real time and automatically trigger the vibration cleaning function. Through the positive piezoelectric effect, the pressure generated by the adhered material is converted into a voltage signal; through the inverse piezoelectric effect, the piezoelectric film is driven to vibrate, efficiently cleaning the adhered material.

[0122] 2. Independent closed-loop control unit ensures efficient operation.

[0123] The system achieves closed-loop control by continuously monitoring the voltage signal of each individual unit, ensuring a precise and thorough cleaning process. Voltage signal changes are monitored in real time during vibration cleaning. Vibration automatically stops once the adhering material is completely removed, preventing energy waste.

[0124] 3. Improve equipment efficiency and lifespan

[0125] By promptly cleaning adhering materials, the screw conveyor maintains efficient operation and extends equipment lifespan. It prevents increased equipment resistance or mechanical damage caused by material buildup. This reduces manual intervention and maintenance costs, improving the overall efficiency of the production line.

[0126] The above description discloses only one or more preferred embodiments of the present utility model, and should not be construed as limiting the scope of the present utility model. Those skilled in the art can understand that implementing all or part of the above embodiments and making equivalent changes in accordance with the claims of the present utility model are still within the scope of the utility model.

Claims

1. A rare earth powder intelligent driven anti-sticking conveying system, characterized in that, It includes a feeding device and a screw conveyor, with the feeding device and the screw conveyor connected in sequence; The feeding device includes a split hopper, an upper valve, and a lower valve. The upper valve divides the split hopper into upper and lower parts, and the lower valve is located between the split hopper and the screw conveyor. The screw conveyor includes a motor, a central shaft, helical blades, and a housing. The surfaces of the central shaft, helical blades, and the inner wall of the housing are all covered with a piezoelectric film, which is composed of multiple independent units spliced ​​together.

2. The intelligent driven anti-sticking conveying system for rare earth powder as described in claim 1, characterized in that, The piezoelectric film independent unit on the central axis is parallelogram in shape, while the piezoelectric film independent unit on the inner wall of the housing is rectangular in shape.

3. The intelligent driven anti-sticking conveying system for rare earth powder as described in claim 2, characterized in that, The shape of the individual piezoelectric film units on the helical blades is determined by the side cross-sectional shape of the helical blades, dividing the ring into six parts to cover different areas on the side of each helical blade.

4. The intelligent driven anti-sticking conveying system for rare earth powder as described in claim 3, characterized in that, In each independent piezoelectric film unit, the two ends of the piezoelectric film are fixed, while there is a certain gap between the piezoelectric film and the surface in the middle.

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