Low-dust high-precision screw powder feeding device and using method thereof

Abstract

The invention relates to the technical field of powder conveying, and discloses a low-dust high-precision screw powder feeding device which comprises a mounting frame, two fixing hoops are fixedly connected to the top of the inner side of the mounting frame, a same conveying barrel is fixedly mounted between the two fixing hoops, and a discharging port is formed in one end of the conveying barrel; a driving motor is fixedly connected to the end, away from the discharging port, of the conveying barrel, the output end of the driving motor penetrates through the conveying barrel to be fixedly connected with an eccentric rod, the other end of the eccentric rod is fixedly connected with a screw, and the screw is matched with the inner wall of the conveying barrel. By means of the synergistic effect of multiple dustproof structures, dust pollution in the powder conveying process is remarkably reduced, meanwhile, the centrifugal fan is matched with the negative pressure cover to capture dust floating at the discharging port of the conveying barrel in real time, the dust is efficiently separated through the cyclone separator and then collected to the dust collecting frame, the dust recovery rate exceeds 99.5%, the explosion hidden danger caused by dust accumulation is avoided, and the dust collecting efficiency is improved. Powder waste is reduced, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of powder conveying technology, and in particular to a low-dust, high-precision screw powder conveying device and its usage method. Background Technology

[0002] In the field of powder conveying technology, traditional pneumatic conveying systems have many prominent drawbacks, making it difficult to meet the industrial demands for high-precision quantitative feeding and low dust pollution. These systems transport powder via airflow, which easily leads to powder leakage, causing not only severe dust pollution but also posing an explosion risk due to dust accumulation, failing to meet industry safety standards such as OSHA. Furthermore, the large fluctuations in the gas-solid two-phase flow result in low powder delivery accuracy, with errors often exceeding ±10%, failing to meet the precise requirements of scenarios such as 3D printing powder feeding and chemical additive dosing. In addition, pneumatic conveying systems require a continuous high-pressure air source, resulting in high energy consumption during operation and significantly increasing industrial production costs.

[0003] As an alternative to pneumatic conveying systems, traditional screw powder feeding devices also have significant limitations, restricting their application scope. During powder conveying, powder is prone to clogging at the hopper inlet, forming a "bridging" phenomenon that leads to powder feeding interruptions and affects production continuity. On the other hand, when conveying hard powders such as metal powders, traditional screws wear out quickly, which not only reduces powder feeding accuracy but also shortens equipment lifespan and increases maintenance costs. Therefore, a low-dust, high-precision screw powder feeding device was designed. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a low-dust, high-precision screw powder feeding device and its usage method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A low-dust, high-precision screw powder feeding device includes a mounting frame. Two fixing clamps are fixedly connected to the top inner side of the mounting frame. A common feeding cylinder is fixedly installed between the two fixing clamps, with one end of the feeding cylinder serving as a discharge port. A drive motor is fixedly connected to the end of the feeding cylinder furthest from the discharge port. An eccentric rod is fixedly connected to the output end of the drive motor through the feeding cylinder. A screw is fixedly connected to the other end of the eccentric rod, and the screw is adapted to fit the inner wall of the feeding cylinder. The screw is made of ceramic matrix composite material, and its surface is coated with a WC-Co coating. The nitrogen sealing hopper is fixedly embedded at one end of the mounting frame near the drive motor, and the mounting frame has a round hole that matches the bottom of the nitrogen sealing hopper. The nitrogen sealing hopper is connected to the conveying cylinder. The top of the nitrogen sealing hopper is fixedly connected to the top by a buckle. An inflation pipe is provided on the top of one side of the outer wall of the nitrogen sealing hopper. Ultrasonic vibrating pads are fixedly installed on both sides of the bottom of the outer wall of the nitrogen sealing hopper. The frequency of the ultrasonic vibrating pads is 20-40kHz. A reinforcing rod is also fixedly connected between the nitrogen sealing hopper and the mounting frame.

[0006] Furthermore, support legs are fixedly connected to the four corners at the bottom of the mounting frame, and reinforcing ribs are fixedly connected to the middle of the two support legs away from the drive motor. The top of the two reinforcing ribs is fixedly connected to the same positioning platform, and a weighing sensor is fixedly connected to the middle of the top of the positioning platform. A feeding frame is provided on the top of the positioning platform, and handles are provided on both sides of the outer wall of the feeding frame.

[0007] Furthermore, a cyclone separator is fixedly connected to the top of the mounting frame near the feeding frame, and a centrifugal fan is fixedly connected to the air inlet of the cyclone separator through a pipe. The centrifugal fan is fixedly connected to the top of the mounting frame, and a negative pressure hood is fixedly connected to the input end of the centrifugal fan near the discharge port of the conveying cylinder.

[0008] Preferably, a dust collection frame is slidably inserted into the side of the mounting frame near the cyclone separator, a handle is fixedly connected to the outside of the dust collection frame, and the mounting frame has an opening adapted to the dust collection frame and an opening adapted to the bottom discharge end of the cyclone separator.

[0009] Preferably, a PLC control panel is fixedly connected to the outside of the mounting frame, and the PLC control panel is electrically connected to the weighing sensor, centrifugal fan, ultrasonic vibrator and drive motor respectively.

[0010] A method for using a low-dust, high-precision screw powder feeding device includes the following steps: S1: Initialize the device, check the sealing of the nitrogen-sealed silo, connect the inflation pipe to the nitrogen inflation equipment, and set the target powder feeding amount and powder feeding rate parameters through the PLC control panel. S2: Powder filling and sealing: Open the top cover of the nitrogen-sealed silo, load the powder to be conveyed into the silo, close the top cover and fasten the buckle, and fill the silo with nitrogen through the air filling pipe to create a slightly positive pressure inert gas environment inside the silo. S3: Powder feeding start-up and dynamic adjustment. The drive motor, ultrasonic vibrator and centrifugal fan are started through the PLC control panel. The drive motor drives the eccentric rod and screw to rotate. The ultrasonic vibrator generates vibration to promote the powder to fall into the conveying cylinder. The screw conveys the powder to the discharge port and falls into the feeding frame. The weighing sensor detects the weight of the powder in the feeding frame in real time and feeds the data back to the PID controller of the PLC control panel to calculate the deviation ΔW between the actual powder feeding amount and the target value. S4: Parameter adaptive adjustment, the PID controller dynamically updates the control parameters according to the deviation ΔW, and outputs the speed adjustment command to the drive motor to realize closed-loop control of the powder feeding rate; at the same time, according to the difference in powder flowability, the PLC control panel adaptively adjusts the vibration frequency of the ultrasonic vibrator to ensure stable powder falling and avoid bridging. S5: Dust Recovery and Equipment Shutdown. The centrifugal fan draws in floating dust from the outlet through a negative pressure hood, which is then separated by a cyclone separator and collected in a dust collection frame. When the dust delivery rate reaches the target value, the PLC control panel sequentially shuts down the drive motor, ultrasonic vibrator, and centrifugal fan, shuts down the nitrogen charging equipment, and opens the dust collection frame to recover the dust, completing the dust delivery operation.

[0011] The beneficial effects of this invention are as follows: 1. This invention significantly reduces dust pollution during powder conveying through the synergistic effect of multiple dustproof structures. At the same time, the centrifugal fan, in conjunction with the negative pressure hood, can capture the dust floating at the discharge port of the conveying cylinder in real time. After being efficiently separated by the cyclone separator, the dust is collected in the dust collection frame, with a dust recovery rate of over 99.5%. This not only meets industry safety standards such as OSHA and avoids the explosion hazard caused by dust accumulation, but also reduces powder waste and lowers production costs.

[0012] 2. The device constructs a dual closed-loop control system of "weighing feedback - dynamic adjustment". The weighing sensor detects the weight of the powder in the feeding frame in real time and transmits the data to the PLC control panel. The PID controller calculates the deviation ΔW between the actual powder feeding amount and the target value, and dynamically adjusts the speed of the drive motor to control the powder feeding rate of the screw, so that the powder feeding error is controlled within ±1%. In addition, the ultrasonic vibrating plate at the bottom of the nitrogen-sealed hopper can generate high-frequency vibration, which, together with the asymmetrical rotation of the screw driven by the eccentric rod, can effectively destroy the powder agglomeration structure and completely solve the problem of powder "bridging" and clogging at the hopper opening in traditional devices, ensuring that the powder falls stably into the conveying cylinder and meeting the needs of high-precision scenarios.

[0013] 3. The screw uses ceramic matrix composite material as the base and is coated with a high-hardness WC-Co coating with a hardness ≥1400HV. Compared with traditional metal screws, its wear resistance is improved by 5-8 times. When conveying hard powders such as metal powders, it can effectively reduce the wear between the screw and the powder and avoid the decrease in powder feeding accuracy caused by screw wear. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of a low-dust, high-precision screw powder feeding device proposed in this invention. Figure 2 This is a cross-sectional view of the conveying cylinder of a low-dust, high-precision screw powder feeding device proposed in this invention. Figure 3 This is a schematic diagram of the disassembled structure of the positioning table of a low-dust, high-precision screw powder feeding device proposed in this invention. Figure 4 This is a schematic diagram of the structure on one side of the mounting frame of a low-dust, high-precision screw powder feeding device proposed in this invention.

[0015] In the diagram: 1. Mounting frame; 101. PLC control panel; 102. Fixing clamp; 2. Nitrogen-sealed hopper; 201. Inflation pipe; 202. Ultrasonic vibrating plate; 3. Reinforcing rib; 301. Positioning platform; 302. Weighing sensor; 303. Feeding frame; 4. Conveying cylinder; 401. Drive motor; 402. Eccentric rod; 403. Screw; 5. Cyclone separator; 501. Centrifugal fan; 502. Negative pressure hood; 503. Dust collection frame. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] Reference Figure 1-4A low-dust, high-precision screw powder feeding device includes a mounting frame 1. Two fixing clamps 102 are fixedly connected to the top inner side of the mounting frame 1. A common feeding cylinder 4 is fixedly installed between the two fixing clamps 102, with one end of the feeding cylinder 4 serving as a discharge port. A drive motor 401 is fixedly connected to the end of the feeding cylinder 4 furthest from the discharge port. An eccentric rod 402 is fixedly connected to the output end of the drive motor 401 through the feeding cylinder 4. A screw 403 is fixedly connected to the other end of the eccentric rod 402, and the screw 403 is adapted to fit the inner wall of the feeding cylinder 4. The screw 403 is made of ceramic matrix composite material, and its surface is coated with WC-C. The coating has a hardness ≥1400HV. A nitrogen-sealed hopper 2 is fixedly embedded at one end of the mounting frame 1 near the drive motor 401. A round hole adapted to the bottom of the nitrogen-sealed hopper 2 is opened on the mounting frame 1. The nitrogen-sealed hopper 2 is connected to the conveying cylinder 4. A top cover is fixedly connected to the top of the nitrogen-sealed hopper 2 by a buckle. An inflation pipe 201 is provided on the top of one side of the outer wall of the nitrogen-sealed hopper 2. Ultrasonic vibrating plates 202 are fixedly installed on both sides of the bottom of the outer wall of the nitrogen-sealed hopper 2. The frequency of the ultrasonic vibrating plates 202 is 20-40kHz. A reinforcing rod is also fixedly connected between the nitrogen-sealed hopper 2 and the mounting frame 1.

[0019] Furthermore, support legs are fixedly connected to the four corners at the bottom of the mounting frame 1, and reinforcing ribs 3 are fixedly connected to the middle of the two support legs away from the drive motor 401. The same positioning platform 301 is fixedly connected to the top of the two reinforcing ribs 3, and a weighing sensor 302 is fixedly connected to the middle of the top of the positioning platform 301. A feeding frame 303 is provided on the top of the positioning platform 301, and handles are provided on both sides of the outer wall of the feeding frame 303.

[0020] Preferably, a cyclone separator 5 is fixedly connected to the top of the mounting frame 1 near the feeding frame 303, and a centrifugal fan 501 is fixedly connected to the air inlet end of the cyclone separator 5 through a pipe. The centrifugal fan 501 is fixedly connected to the top of the mounting frame 1, and a negative pressure hood 502 is fixedly connected to the input end of the centrifugal fan 501. The negative pressure hood 502 is close to the discharge port of the conveying cylinder 4.

[0021] In this embodiment, a dust collection frame 503 is slidably inserted into the side of the mounting frame 1 near the cyclone separator 5. A handle is fixedly connected to the outside of the dust collection frame 503. The mounting frame 1 has an opening adapted to the dust collection frame 503 and an opening adapted to the bottom discharge end of the cyclone separator 5.

[0022] Furthermore, a PLC control panel 101 is fixedly connected to the outside of the mounting frame 1, and the PLC control panel 101 is electrically connected to the weighing sensor 302, the centrifugal fan 501, the ultrasonic vibrating plate 202 and the drive motor 401 respectively.

[0023] Preferably, it includes the following steps: S1: Initialize the device, check the sealing performance of the nitrogen sealed silo 2, connect the inflation pipe 201 to the nitrogen inflation equipment, and set the target powder feeding amount and powder feeding rate parameters through the PLC control panel 101. S2: Powder filling and sealing: Open the top cover of the nitrogen-sealed silo 2, load the powder to be conveyed into the silo, close the top cover and fasten the buckle, and fill the silo with nitrogen through the air filling pipe 201 to create a slightly positive pressure inert gas environment inside the silo. S3: Powder feeding start-up and dynamic adjustment. The drive motor 401, ultrasonic vibrator 202 and centrifugal fan 501 are started through the PLC control panel 101. The drive motor 401 drives the eccentric rod 402 and screw 403 to rotate. The ultrasonic vibrator 202 generates vibration to promote the powder to fall into the conveying cylinder 4. The screw 403 conveys the powder to the discharge port and falls into the feeding frame 303. The weighing sensor 302 detects the weight of the powder in the feeding frame 303 in real time and feeds the data back to the PID controller of the PLC control panel 101 to calculate the deviation ΔW between the actual powder feeding amount and the target value. S4: Parameter adaptive adjustment, the PID controller dynamically updates the control parameters according to the deviation ΔW, and outputs the speed adjustment command to the drive motor 401 to realize closed-loop control of the powder feeding rate; at the same time, according to the difference in powder flowability, the PLC control panel 101 adaptively adjusts the vibration frequency of the ultrasonic vibrator 202 to ensure stable powder falling and avoid bridging phenomenon. S5: Dust recovery and device shutdown. Centrifugal fan 501 sucks in the floating dust at the outlet through negative pressure cover 502, and collects it into dust collection frame 503 after separation by cyclone separator 5. When the dust feeding amount reaches the target value, PLC control panel 101 sequentially shuts down drive motor 401, ultrasonic vibrator 202 and centrifugal fan 501, shuts down nitrogen charging equipment, and opens dust collection frame 503 to recover dust, completing the dust feeding operation.

[0024] Working Principle: When using this device, open the top cover of the nitrogen-sealed silo 2, add powder into the silo, and seal it. Then connect the outer end of the inflation pipe 201 to the nitrogen inflation pump to continuously supply gas to the inside of the nitrogen-sealed silo 2. Set the target powder feeding amount and feeding rate parameters through the PLC control panel 101, and turn on the drive motor 401. This causes the drive motor 401 to drive the eccentric rod 402 and the screw 403 to rotate. The eccentric rod 402 causes the screw 403 to rotate asymmetrically inside the conveying cylinder 4. The screw 403 can oscillate in a circular motion and rotate on its own axis within the inner wall of the conveying cylinder 4. The opening of the two ultrasonic vibrating plates 202 allows the powder inside the nitrogen-sealed silo 2 to enter... In the feeding cylinder 4, as the screw 403 conveys the powder to the feeding frame 303, the weighing sensor 302 detects the weight of the powder in the feeding frame 303 in real time and feeds the data back to the PID controller of the PLC control panel 101. The controller calculates the deviation ΔW between the actual powder feeding amount and the target value. In conjunction with the PLC control panel 101, the controller controls the rotation of the drive motor 401 in real time. The introduction of nitrogen gas can protect the powder conveying. The centrifugal fan 501 is turned on, so that a negative pressure is generated at the negative pressure hood 502. When the powder in the feeding cylinder 4 falls into the feeding frame 303, a small amount of powder floating can be conveyed to the cyclone separator 5 through the negative pressure hood 502 and the centrifugal fan 501. Through the separation of the cyclone separator 5, the powder is recovered into the dust collection frame 503.

[0025] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0026] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A low-dust, high-precision screw powder feeding device, comprising a mounting frame, characterized in that, Two fixing clamps are fixedly connected to the top inner side of the mounting frame. A common feeding cylinder is fixedly installed between the two fixing clamps, and one end of the feeding cylinder is a discharge port. A drive motor is fixedly connected to the end of the feeding cylinder away from the discharge port. An eccentric rod is fixedly connected to the output end of the drive motor through the feeding cylinder, and a screw is fixedly connected to the other end of the eccentric rod. The screw is adapted to the inner wall of the feeding cylinder. The screw is made of ceramic matrix composite material, and the surface of the screw is coated with WC-Co coating with a hardness ≥1400HV. A nitrogen-sealed hopper is fixedly embedded at one end of the mounting frame near the drive motor. The mounting frame has a circular hole that matches the bottom of the nitrogen-sealed hopper. The nitrogen-sealed hopper is connected to the conveying cylinder. A top cover is fixedly connected to the top of the nitrogen-sealed hopper by a buckle. An inflation pipe is provided on the top of one side of the outer wall of the nitrogen-sealed hopper. Ultrasonic vibrating pads are fixedly installed on both sides of the bottom of the outer wall of the nitrogen-sealed hopper. The frequency of the ultrasonic vibrating pads is 20-40kHz. A reinforcing rod is also fixedly connected between the nitrogen-sealed hopper and the mounting frame.

2. The low-dust, high-precision screw powder feeding device according to claim 1, characterized in that, Support legs are fixedly connected to the four corners at the bottom of the mounting frame, and reinforcing ribs are fixedly connected to the middle of the two support legs away from the drive motor. The top of the two reinforcing ribs is fixedly connected to the same positioning platform, and a weighing sensor is fixedly connected to the middle of the top of the positioning platform. A feeding frame is provided on the top of the positioning platform, and handles are provided on both sides of the outer wall of the feeding frame.

3. The low-dust, high-precision screw powder feeding device according to claim 1, characterized in that, A cyclone separator is fixedly connected to the top of the mounting frame near the feeding frame, and a centrifugal fan is fixedly connected to the air inlet of the cyclone separator through a pipe. The centrifugal fan is fixedly connected to the top of the mounting frame, and a negative pressure hood is fixedly connected to the input end of the centrifugal fan near the discharge port of the conveying cylinder.

4. The low-dust, high-precision screw powder feeding device according to claim 1, characterized in that, A dust collection frame is slidably inserted into the side of the mounting frame near the cyclone separator. A handle is fixedly connected to the outside of the dust collection frame. The mounting frame has openings that match the dust collection frame and openings that match the bottom discharge end of the cyclone separator.

5. The low-dust, high-precision screw powder feeding device according to claim 1, characterized in that, A PLC control panel is fixedly connected to the outside of the mounting frame, and the PLC control panel is electrically connected to the weighing sensor, centrifugal fan, ultrasonic vibrator and drive motor respectively.

6. A method of using a low-dust, high-precision screw powder feeding device, based on the device according to any one of claims 1, characterized in that, Includes the following steps: S1: Initialize the device, check the sealing of the nitrogen-sealed silo, connect the inflation pipe to the nitrogen inflation equipment, and set the target powder feeding amount and powder feeding rate parameters through the PLC control panel. S2: Powder filling and sealing: Open the top cover of the nitrogen-sealed silo, load the powder to be conveyed into the silo, close the top cover and fasten the buckle, and fill the silo with nitrogen through the air filling pipe to create a slightly positive pressure inert gas environment inside the silo. S3: Powder feeding start-up and dynamic adjustment. The drive motor, ultrasonic vibrator and centrifugal fan are started through the PLC control panel. The drive motor drives the eccentric rod and screw to rotate. The ultrasonic vibrator generates vibration to promote the powder to fall into the conveying cylinder. The screw conveys the powder to the discharge port and falls into the feeding frame. The weighing sensor detects the weight of the powder in the feeding frame in real time and feeds the data back to the PID controller of the PLC control panel to calculate the deviation ΔW between the actual powder feeding amount and the target value. S4: Parameter adaptive adjustment, the PID controller dynamically updates the control parameters according to the deviation ΔW, and outputs the speed adjustment command to the drive motor to realize closed-loop control of the powder feeding rate; at the same time, according to the difference in powder flowability, the PLC control panel adaptively adjusts the vibration frequency of the ultrasonic vibrator to ensure stable powder falling and avoid bridging. S5: Dust recovery and device shutdown. The centrifugal fan sucks in the floating dust at the outlet through the negative pressure hood, and after being separated by the cyclone separator, it is collected in the dust collection frame. When the dust feeding amount reaches the target value, the PLC control panel sequentially shuts down the drive motor, ultrasonic vibrator and centrifugal fan, shuts down the nitrogen charging equipment, and opens the dust collection frame to recover the dust, thus completing the dust feeding operation.

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