Pneumatic-based powder packaging system and method

Abstract

The invention relates to the technical field of powder material packaging, and particularly discloses a pneumatic-based powder packaging system and method. The system comprises a gas screen control module, a separation and purification module and a pressure regulation module. The air screen control module generates and generates an air curtain barrier with adjustable strength through an air screen device, and the controller dynamically adjusts the sealing strength according to an instruction; the separation and purification module realizes powder recovery and gas purification; the pressure adjusting module maintains system pressure balance. The system automatically switches operation modes according to the packaging stage: in the container positioning stage, the air curtain barrier prevents the powder from passing through, and the separation device recovers the powder in the airflow; and in the quantitative filling stage, the system maintains positive pressure, so that the powder smoothly passes through and dust is prevented from escaping. Non-contact type dynamic sealing replaces a mechanical valve, the problems of dust leakage, cross contamination, frequent maintenance and the like are solved, and the non-contact type dynamic sealing powder packaging machine is suitable for powder packaging scenes with high cleanliness requirements such as food, medicine and chemical engineering.

Description

Technical Field

[0001] This invention relates to the field of powder material packaging technology, and in particular to a pneumatic powder packaging system and method. Background Technology

[0002] Powder packaging technology is a core component of modern industrial production. In industries with high cleanliness and precision requirements, such as food, pharmaceuticals, and chemicals, the packaging of pipeline-transported powders (e.g., milk powder, pharmaceutical powders, fine chemical raw materials with particle sizes within 1mm) often requires: quantitative filling to ensure controllable weight deviation for each batch; pollution-free operation to prevent the powder from being affected by external impurities and mechanical contaminants; and adaptive control to dynamically adjust operating parameters according to changes in working conditions. Among these, pipeline opening and closing control is the key core of powder packaging, and its performance directly determines packaging accuracy, cleanliness, powder utilization rate, and production safety. In such applications, the packaging system places extremely stringent requirements on the pipeline opening and closing device: First, it must ensure extremely high sealing performance to prevent cross-contamination and powder loss caused by leakage; second, it must achieve rapid response to meet the precise cycle time matching between the automated packaging line and downstream equipment; and third, it must eliminate the risk of powder contamination, denaturation, or static electricity accumulation caused by mechanical contact, which is crucial for maintaining food, drug, and chemical safety and preventing dust explosions.

[0003] However, existing technologies face significant bottlenecks in pipeline opening and closing control. Currently, mainstream valve opening and closing technologies in the industrial field are mainly divided into two categories: traditional mechanical valves and pneumatic valves, both of which have obvious technical shortcomings. Traditional mechanical valves are the most widely used solution, including butterfly valves, ball valves, and gate valves. Typical examples include the discharge valve structure of a powder packaging machine (CN112249825A), the mechanical shut-off valve of a quantitative packaging machine (CN113233432A), and the powder delivery pipeline shut-off valve (CN222163606U). Pneumatic valves improve response speed through air pressure actuation, but still remain limited by mechanical contact. Typical technologies include the pneumatic stop valve of a powder packaging machine (CN114567891A) and the anti-jamming pneumatic valve (CN115678932A). The aforementioned valve technology exhibits significant drawbacks in actual powder packaging operations: First, relying on the physical movement of mechanical components such as valve cores and gates to achieve sealing results in an inertial delay in response, making it difficult to meet the frequency requirements of high-speed packaging lines. Furthermore, the direct contact between mechanical components and powder easily leads to powder shearing, fragmentation, crusting, and contamination by lubricating oil. Second, valve cores and seals are prone to wear under the scouring of high-speed powder, resulting in seal failure and leakage. This not only increases powder loss but also necessitates frequent shutdowns for maintenance. Third, existing packaging valve technologies generally lack adaptive adjustment capabilities. During powder packaging, changes in powder characteristics and flow fluctuations often cause system pressure changes, and traditional valves cannot dynamically adjust according to these pressure changes, easily leading to decreased packaging accuracy or dust escape.

[0004] Furthermore, while existing air curtain technologies include sealing solutions, they are primarily used for dust removal and isolation, not for controlling the opening and closing of powder packaging. For example, the dust removal air curtain device (CN118765432A) for powder packaging machines is only used for dust collection, and the packaging line air curtain isolation system (CN119876543A) achieves area isolation through the air curtain. The main problems with this type of technology are: the lack of dynamic opening and closing function, achieving only static sealing and unable to actively control the passage and interception of powder; and the lack of dynamic adjustment function, unable to adjust the air curtain parameters according to pressure changes during the packaging process.

[0005] In summary, existing powder packaging valve technologies generally suffer from drawbacks such as slow response speed, inaccurate control, mechanical contact contamination, high maintenance costs, and a lack of pressure feedback and adaptive control, failing to meet the demands of modern industry for high-precision, pollution-free, and adaptive powder packaging. Therefore, developing a powder packaging system and method based on an air curtain barrier, integrating gas-solid separation, and possessing intelligent pressure regulation is key to overcoming current technological bottlenecks. Summary of the Invention

[0006] The purpose of this application is to address the problems existing in the prior art by providing a pneumatic-based powder packaging system and method.

[0007] According to a first aspect of the embodiments of this application, a pneumatic-based powder packaging system is provided, including an air screen control module, a separation and purification module, and a pressure regulation module; The separation and purification module uses a separation device for gas-solid separation, which is provided with a feed inlet, a discharge outlet and an exhaust outlet, wherein the feed inlet is located at the outlet of the powder discharge pipe and the exhaust outlet is located between the feed inlet and the discharge outlet. The pressure regulation module includes a pressure sensor, a positive pressure device, an exhaust pipe, and a filter device. The inlet end of the exhaust pipe is connected to the exhaust port, and the outlet end is connected to the filter device. Gas is discharged to the outside through the filter device. The pressure sensor and the positive pressure device are installed on the exhaust pipe, which are used to detect pressure data and regulate air pressure, respectively. The air curtain control module includes a controller and two air curtain devices. The first air curtain device is coaxially disposed between the output end of the powder discharge pipe and the inlet, and the second air curtain device is coaxially disposed at the discharge port. It is used to generate an air curtain barrier with adjustable strength. The controller is used to receive instructions and generate corresponding control signals to dynamically adjust the sealing strength of the air curtain barrier.

[0008] In one possible implementation, a dustproof device is provided at the powder outlet below the second air shield device. The dustproof device is signal-connected to the controller and is configured to receive controller instructions and act during the quantitative filling stage to physically seal the opening of the packaging container.

[0009] In one possible implementation, the air shield device adopts an annular air knife, an annular air nozzle, or a fan-shaped nozzle structure, with its inner ring diameter adapted to the inner diameter of the pipe, and the air hole design ensuring that the airflow uniformly covers the entire pipe cross-section.

[0010] In one possible implementation, the separation and purification module employs a cyclone separator, a cartridge dust collector, or a bag filter.

[0011] In one possible implementation, the positive pressure device employs a centrifugal fan, a Roots blower, or a compressed air system.

[0012] In one possible implementation, at least one air shield device is also included, with the air shield devices connected to each other via the separation device, and the strength of each air shield device decreasing progressively from top to bottom.

[0013] According to a second aspect of the embodiments of this application, a pneumatically based powder packaging method is provided, employing the system described in the first aspect, the method comprising: S1: System initialization, the controller receives the packaging instruction and enters the working mode; S2: During the container positioning phase, the controller responds to the container positioning command by activating the first air shield device and the second air shield device to form a gradient sealing barrier, wherein the first air shield device generates the main barrier and the second air shield device provides auxiliary protection. At the same time, the separation and purification module is activated to separate the powder-containing airflow. S3: During the quantitative filling stage, the controller confirms that the container positioning is complete, switches to the quantitative filling mode, activates the dustproof device to seal the opening of the packaging container, adjusts the air shield device to a slightly positive pressure state, and activates the positive pressure device to maintain the positive pressure environment of the system, so that the powder passes through under pressure and achieves filling. S4: Real-time monitoring of system pressure parameters and adjustment of each module via controller; S5: The system resets after filling is complete.

[0014] In one possible implementation, the specific operations of the container positioning phase in step S2 include: Upon receiving the container positioning command, the controller immediately activates the first and second air shield devices. The first air shield device generates a high-intensity air curtain as the main barrier, while the second air shield device provides auxiliary protection. The separation and purification module starts simultaneously to efficiently separate the powder-containing airflow generated during the sealing process.

[0015] In one possible implementation, the specific operations of the quantitative filling stage in step S3 include: Once the controller confirms that the container is positioned correctly, it switches the system to quantitative filling mode. Activate the dustproof device to form a physical seal by tightly fitting the opening of the packaging container; Adjust the air shield device to a slightly positive pressure state, and the airflow speed will be reduced to a low level; Activate the positive pressure device to maintain a positive pressure environment in the system at or slightly higher than the pipeline delivery pressure; The powder flows smoothly under pressure, achieving precise filling.

[0016] In one possible implementation, the packaging instruction may be derived from at least one of the following: a manual instruction issued by an operator, a linkage control signal issued by an upstream or downstream device, or a trigger instruction automatically generated by a controller based on preset conditions.

[0017] The technical solutions provided by the embodiments of this application may include the following beneficial effects: (1) The present invention uses air curtain dynamic sealing to replace mechanical valves, which completely avoids direct contact between mechanical parts and powder, fundamentally eliminating the problems of powder shearing and crushing, lubricating oil pollution and mechanical wear, and is particularly suitable for packaging scenarios with high cleanliness requirements.

[0018] (2) By integrating pressure sensors and adaptive algorithms, the system can monitor the working conditions in real time and dynamically adjust the air curtain barrier and system pressure, realizing the leap from fixed mode to intelligent adaptive control, and significantly improving packaging accuracy and stability.

[0019] (3) The present invention realizes the coordination between the separation and purification module and the air screen control, forming a complete gas-solid separation and powder recovery system, which improves the powder utilization rate, ensures clean emission, and reduces maintenance costs.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] Figure 1 This is a schematic diagram of the structure of the pneumatic powder packaging system of the present invention.

[0023] Figure 2 This is a schematic diagram of the container positioning stage of the pneumatic powder packaging system of the present invention.

[0024] Figure 3 This is a schematic diagram of the quantitative filling stage of the pneumatic powder packaging system of the present invention. Detailed Implementation

[0025] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application.

[0026] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0027] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0028] like Figure 1-3 As shown, this application provides a pneumatic powder packaging system, the core of which is to replace mechanical contact with an air curtain barrier to achieve dynamic sealing and precise control of the powder. It can be adapted to a variety of chemical / food / pharmaceutical powders and granular powders, including but not limited to powders with different properties such as PTFE, PVDC, PVDF, and polypropylene. The system includes an air curtain control module, a separation and purification module and a pressure regulation module. The separation and purification module uses a separation device for gas-solid separation, which is provided with a feed inlet, a discharge outlet and an exhaust outlet, wherein the feed inlet is located at the outlet of the powder discharge pipe and the exhaust outlet is located between the feed inlet and the discharge outlet. The pressure regulation module includes a pressure sensor, a positive pressure device, an exhaust pipe, and a filter device. The inlet end of the exhaust pipe is connected to the exhaust port, and the outlet end is connected to the filter device. Gas is discharged to the outside through the filter device. The pressure sensor and the positive pressure device are installed on the exhaust pipe, which are used to detect pressure data and regulate air pressure, respectively. The air curtain control module includes a controller and two air curtain devices. The first air curtain device is coaxially disposed between the output end of the powder discharge pipe and the inlet, and the second air curtain device is coaxially disposed at the discharge port. It is used to generate an air curtain barrier with adjustable strength. The controller is used to receive instructions and pressure data and generate corresponding control signals to dynamically adjust the sealing strength of the air curtain barrier and control the positive pressure device.

[0029] In one embodiment, the powder discharge pipe is made of 316L stainless steel, with a diameter of 200mm and a wall thickness of 5mm, and is vertically arranged. Polyethylene powder is conveyed at a flow rate of 1.5m / s, and the working pressure is stabilized at 2000Pa±200Pa. The air shield device of the air shield control module is coaxially installed in the outlet area of ​​the pipe and the interface area of ​​the separation device. The inlet of the separation and purification module is located below the first air shield device, and the exhaust pipe of the pressure regulating module is connected to the exhaust port of the separation device. All modules are connected via explosion-proof cables and are uniformly controlled by a controller, meeting the explosion-proof requirements of chemical workshops.

[0030] In practical implementation, the air curtain control module is the core control unit of the system, integrating the controller and the air curtain device. Its core function is to receive operation commands, including manual commands issued by operators, linkage control signals issued by upstream or downstream equipment, or trigger commands automatically generated by the controller according to preset internal conditions. It then uses air pressure to drive the generation of an adjustable-strength air curtain barrier, replacing the physical contact seal of traditional mechanical valves. Simultaneously, it receives pressure data and outputs adjustment commands.

[0031] The controller can be a programmable logic controller (PLC), industrial computer, host system, cloud system, etc., connected to each module via signal lines, receiving instructions in real time. These instructions can be manual commands issued by operators, linkage control signals issued by upstream or downstream equipment, or trigger commands automatically generated by the controller based on preset internal conditions, and output precise control signals accordingly. Through built-in control algorithms (e.g., pressure analysis algorithms and adaptive adjustment logic based on PID control, fuzzy logic control, or model predictive control), the sealing strength of the air shield can be automatically adjusted according to the system operating status, achieving intelligent control. Specifically, taking the PID control algorithm as an example, its input is the deviation between the system pressure setpoint and the sensor's measured value. By linearly combining the proportional, integral, and derivative of the deviation, the output is a control signal that adjusts the airflow speed or air pressure of the air shield device, thus forming a closed-loop feedback control to quickly stabilize the system pressure. In the PID algorithm, the proportional term (P) is used to quickly respond to pressure deviation, the integral term (I) is used to accumulate and eliminate steady-state error, and the derivative term (D) is used to predict pressure change trends and suppress overshoot; the three work together to enable the system to smoothly and accurately reach and maintain the target pressure setpoint.

[0032] The air shield device forms a non-contact dynamic seal through the synergistic effect of two air shields. The strength of the first air shield is much greater than that of the second air shield. The first air shield provides the primary barrier function, while the second air shield provides auxiliary protection, creating a gradient sealing effect. The air shield device can adopt various structural forms such as annular air knives, annular air nozzles, and fan-shaped nozzles, and can be connected to an external air source. The materials of the air shield device and its fixing system should meet the requirements of the industry to which the pipeline belongs. Its inner ring diameter should be compatible with the inner diameter of the powder discharge pipeline, and it should be coaxially fixed to the pipeline end face. The airflow direction should be basically perpendicular to the powder conveying direction of the pipeline. The air hole design ensures that the airflow can evenly cover the entire cross-section of the pipeline opening, forming a gapless air curtain barrier. The first air shield device is coaxially installed at the outlet of the powder discharge pipeline, and the second air shield device is coaxially installed at the outlet of the separation device. During operation, the system automatically switches modes according to the packaging stage: such as... Figure 2 During the container positioning stage shown, an air curtain barrier prevents powder from passing through; as Figure 3 During the quantitative filling stage shown, the system maintains positive pressure to allow the powder to pass through smoothly.

[0033] In one embodiment, the air shield device uses a 316L stainless steel annular air knife with an inner ring diameter of 200mm, adapted to the pipe diameter. The outlet width is 1.2mm to ensure uniform airflow coverage of the pipe cross-section. It is fixed to the pipe via a DN200 flange, with an installation coaxiality error ≤1mm. The air source is connected to the workshop compressed air system (pressure 0.5-0.7MPa), equipped with a three-stage filtration and electrostatic elimination device. The controller is a Schneider M340 series explosion-proof PLC.

[0034] In practical implementation, the separation device of the separation and purification module can adopt different forms such as cyclone separators, cartridge dust collectors, and bag filters. Furthermore, multiple devices can be cascaded to effectively recover powder from the airflow through multi-stage separation technology. During system operation, the separation device works continuously to ensure full powder recovery while simultaneously purifying the gas. The separation and purification module is equipped with a dustproof device at the powder outlet below the second air shield device. During the quantitative filling stage, this device is driven by controller commands to physically seal the packaging container opening through downward movement, unfolding, or rotation. The dustproof device includes a flexible sealing cover and a movable lid connected from top to bottom, with its material and driving method adapted to the characteristics of the packaged material. The upper end of the flexible sealing cover is connected to the powder outlet of the second air shield device and is adapted to the pipe outer diameter. The lower end of the movable lid is connected to the container opening and is adapted to the container opening outer diameter, forming a complete physical seal.

[0035] In one embodiment, the separation device employs a combination design of a cyclone separator and a cartridge dust collector. The inlet is connected to the pipe below the first air shield device via a flange, and the outlet is located above the second air shield device. The separation efficiency is ≥99.5%, and the filter cartridges are made of PTFE membrane material with a filtration accuracy of 0.3μm. The dustproof device uses a wear-resistant, food-grade silicone flexible sealing cover driven by a cylinder, which is installed below the second air shield device via a bracket, and its inner diameter is adapted to the outer diameter of the container opening. After receiving the container positioning completion signal, the controller outputs a command to the drive unit, causing the sealing cover to form a tight seal with the container opening at a preset pressure. The exhaust pipe is made of 316L stainless steel with a diameter of 50mm, and is connected to the gas outlet of the separation device by a clamp to ensure sealing.

[0036] In practical implementation, the pressure regulation module includes a pressure sensor connected to the controller via a signal line, sending real-time pressure detection data. The positive pressure device can take various forms, such as a centrifugal fan, a Roots blower, or a compressed air system. It can be connected to an external air source and, via a signal line, connects to the controller to receive commands and intelligently regulate to maintain the required positive pressure state of the system. Pressure regulation methods include, but are not limited to, front-end flow control (such as adjusting the intake valve opening via a proportional valve, butterfly valve, or electric regulating valve), power source output regulation (such as using a frequency converter to adjust the fan speed or using closed-loop feedback control of the intake volume based on a flow meter), and system-level buffering and compensation (such as introducing a pressure buffer tank or adjusting the system volume). The exhaust pipeline is equipped with a high-efficiency filter to ensure that the emitted gas meets industry and site requirements.

[0037] In one embodiment, the positive pressure device uses an explosion-proof centrifugal fan with an adjustable air volume range of 10-100 m³ / h. 3 / h. Connected to the system via an explosion-proof hose, it is equipped with a pressure sensor to monitor system pressure in real time. The filtration system is a three-stage filtration system (pre-filter + medium-efficiency filter + HEPA filter) installed at the end of the exhaust pipe, ensuring that the cleanliness of the exhaust gas meets the ISO 8573-1:2010 standard.

[0038] The pneumatic powder packaging system operates on intelligent control logic, automatically switching between two main stages: container positioning and quantitative filling, triggered by operational commands and system status. The entire workflow revolves around the coordinated operation of the air shield control module, separation and purification module, and pressure regulation module. The workflow is described in detail below, stage by stage.

[0039] 1. Container positioning phase ( Figure 2 ) The core objective at this stage is to establish an effective non-contact sealing barrier to create conditions for precise alignment of packaging containers while preventing powder spillage.

[0040] (1) Phase Startup and System Initialization The process begins when the system receives a container positioning command. This command can originate from manual commands issued by the operator through the human-machine interface, linkage control signals from upstream conveying equipment or downstream packaging machines, or trigger commands automatically generated by the controller based on preset conditions (such as detecting a container positioning signal). The controller responds immediately and enters the container positioning working mode. The controller sends initialization commands to each module through signal lines and begins to collect operating parameters such as system pressure in real time.

[0041] (2) Formation and maintenance of dynamic sealing barriers The controller sends commands to the air curtain devices, activating both the first and second air curtains. The first air curtain acts as the primary barrier, generating a high-intensity air curtain to provide the main blocking effect; the second air curtain acts as an auxiliary barrier, providing supplementary protection with a lower air curtain. Together, they create a gradient sealing effect, effectively preventing powder from passing through the pipeline. Based on real-time pressure data, the controller dynamically adjusts the air pressure and flow rate of the air curtain using a built-in advanced control algorithm, precisely controlling the sealing strength to ensure the stability and effectiveness of the barrier.

[0042] While forming an air curtain barrier, the airflow carrying a small amount of powder enters the separation and purification module. The airflow enters the gas-solid separation device (such as a cyclone separator or cartridge dust collector) through the inlet located below the first air curtain device. Inside the separation device, efficient gas-solid separation is achieved using centrifugal force or filtration principles. The trapped powder particles settle through the outlet (located above the second air curtain device) under gravity and return to the system for recycling, preventing powder loss. The separated clean gas enters the connected exhaust pipe through the exhaust port, where it undergoes final purification by the filtration device in the pressure regulating module to ensure that the emitted gas meets requirements.

[0043] The pressure regulation module continuously monitors the internal pressure of the system.

[0044] The controller continuously receives feedback signals from the conveying device (such as a container positioning sensor). Once it is confirmed that the packaging container has been accurately aligned and secured, the system is ready to wait for or automatically trigger the switch to the next stage.

[0045] In one embodiment, the controller activates the dual air shield device, increasing the airflow velocity to 4.0-4.5 m / s to form a gradient sealing barrier, and maintaining the air curtain pressure at 2300 Pa (300 Pa higher than the pipeline pressure). Simultaneously, the separation and purification module is activated to efficiently separate and recover the powder-containing airflow generated during the sealing process.

[0046] 2. Quantitative filling stage ( Figure 3 ) This stage is performed after the container is accurately positioned. The core objective is to achieve high-precision and pollution-free filling of powder into the packaging container under a controllable positive pressure environment.

[0047] (1) Phase switching and mode conversion Once the controller confirms that the container has been positioned, it immediately issues a command to switch the system's operating mode from container positioning to quantitative filling.

[0048] After receiving the instruction, the dustproof device moves down or unfolds to cover the opening of the packaging container, forming a physical barrier during filling and preventing the powder from escaping.

[0049] After receiving the command, the air curtain device significantly reduces the air curtain barrier strength of the first and second air curtains. The function of the air curtain barrier changes from "complete blockage" to "protection," that is, allowing the main flow of powder to pass smoothly while maintaining a weak barrier with slight positive pressure to prevent powder, dust, etc. from entering the air holes or nozzles of the air curtain device, causing blockage or contamination.

[0050] (2) Positive pressure filling The controller commands the positive pressure device (such as a centrifugal fan, compressed air system, etc.) in the pressure regulation module to start or increase the output, so as to establish and maintain a stable positive pressure environment inside the separation device and prevent the powder from being lost from the exhaust pipe.

[0051] Driven by positive pressure in the pipeline powder conveying system, the upstream powder begins to flow through the pipeline at a stable and controllable flow rate. The powder sequentially passes through the first air shield area, which has been adjusted to a slightly positive pressure state, the separation and purification module, and finally through the dustproof device below the second air shield device, before being poured into the packaging container below.

[0052] The controller adjusts the pressure of the positive pressure device according to the preset filling volume, and combines it with the weighing device in the conveying device to achieve precise control of the powder flow rate, ensuring the filling accuracy of each container.

[0053] In this embodiment, as Figure 3 As shown, after the container is positioned, the dustproof device covers the container opening, and the controller adjusts the air shield device to a slightly positive pressure state (airflow velocity ≤ 0.1m / s). The positive pressure device is activated to maintain a positive pressure environment (2100Pa) in the system, ensuring smooth powder passage while preventing dust escape, thus achieving accurate filling. The separation device continuously purifies the gas. The system is set with a pressure fluctuation threshold of ±100Pa, and automatically adjusts the air curtain intensity when an abnormal pressure is detected. In this embodiment, the input of the PID algorithm is the difference between the target pressure (e.g., 2300Pa or 2100Pa) and the measured value of the pressure sensor, and the output is the command signal driving the actuator of the air shield device (e.g., a proportional valve). By adjusting the weights of the three parameters P, I, and D, the system's response speed and stability are optimized.

[0054] When the controller detects that the filling volume has reached the set value, or receives a filling completion command from the conveyor, it determines that filling is complete. The controller issues a stop command, the positive pressure device lowers or stops output, the air shield device can be adjusted according to the needs of the next cycle (e.g., strengthening the barrier while waiting for the next container to be positioned), and the dustproof device moves up or retracts. The system resets, preparing for the next packaging cycle. If it is a continuous operation, the next container positioning stage is triggered directly, starting a new workflow.

[0055] The above system was tested on a chemical polyethylene powder packaging line for 30 days, and the results showed: Sealing performance: Zero powder escape can be achieved during the container positioning stage, and the sealing effect fully meets the design requirements.

[0056] Filling accuracy: The weight error during the quantitative filling stage is ≤ ±0.5%, meeting the requirements of high-precision packaging.

[0057] Adaptability: The system automatically adjusts under pressure fluctuations and operates stably.

[0058] Maintenance cost: The filter cartridge is replaced every 30 days, and the air shield device is not worn. The maintenance cost is reduced by 60% compared with traditional mechanical valves (based on statistics of filter cartridge replacement frequency and mechanical valve wear rate during 30-day trial operation).

[0059] To address the needs of different application scenarios, the following two implementation schemes are provided, including a simplified scheme and an advanced scheme, with detailed implementation specifications. It is important to emphasize that all schemes are implemented based on specific operating conditions.

[0060] 1. Simplified scheme design and application under stable operating conditions When the powder packaging system operates in a stable environment with minimal pressure fluctuations (≤±100Pa), minimal impact of airflow from the air shield on filling, and stable operating conditions (e.g., low-load continuous production, short-distance stable conveying, or scenarios with uniform powder characteristics), a simplified system configuration can be adopted. This solution retains the core air shield control module while omitting the separation purification module and pressure regulation module to reduce costs and maintenance complexity, while ensuring basic packaging functions. The simplified system structure is based on... Figure 1 The basic architecture shown is used, but only the core air shield components are retained. Implementation details of this solution are as follows: System Configuration: The simplified solution includes only the air shield control module, consisting of a controller and a single air shield device (such as a ring-shaped air knife). The air shield device is coaxially mounted at the pipe outlet, with its inner ring diameter adapted to the pipe's inner diameter (e.g., a 200mm pipe with a 200mm air knife), and the airflow direction is substantially perpendicular to the powder flow direction. The controller uses a basic PLC with preset fixed parameters, omitting pressure sensors and adaptive algorithms.

[0061] Workflow: During the container positioning stage, the controller activates the air curtain device to create an air curtain barrier of fixed strength (airflow velocity preset to 3.8-4.0 m / s) to prevent powder from passing through; during the quantitative filling stage, the air curtain strength is reduced to a lower fixed value (airflow velocity ≤ 0.1 m / s), allowing the powder to flow smoothly. Due to the stable operating conditions, the fixed parameters are sufficient to maintain the seal, and no real-time adjustment is required.

[0062] Applicable conditions: This solution is strictly applicable to scenarios with minimal pressure fluctuations (≤±100Pa) and negligible interference from the air shield outlet on powder flow. For example, when processing polypropylene powder with uniform density, if the system pressure is stable at 2000Pa±50Pa and the pipeline flow rate is constant, the simplified solution can work effectively.

[0063] Advantages and limitations: Simple structure and low cost, but lacks adaptability and is not suitable for scenarios with large pressure fluctuations or varied powder properties. Implementation requires prior testing to verify operational stability.

[0064] 2. Advanced multi-level air screen solutions for demanding scenarios For industries with high cleanliness requirements, such as food and pharmaceuticals, or when handling flammable, explosive, or high-value powders (such as pharmaceutical powders), where high cleanliness requirements, large pressure fluctuations, or complex operating conditions necessitate a multi-stage air shield advanced solution. This solution adds a third air shield device to the existing dual air shield system. This third air shield device is positioned below the second air shield device, and a separation device is installed between the second and third air shields. The strength of the first, second, and third air shields decreases progressively, and they work together to control the airflow, forming a three-stage gradient seal, thus improving system reliability and adaptability. The system layout of the advanced solution is referenced below. Figure 1 However, the air shield structure has been expanded to three levels, and the workflow can be combined with... Figure 2 and Figure 3 The stage shown. If necessary, this scheme can be further expanded into a four-, five-, or even more-stage air shield structure. Implementation details are as follows: System Configuration: The system includes an air shield control module, a separation and purification module, and a pressure regulation module, but the air shield device has been upgraded to a three-stage structure. The first air shield serves as the main barrier (high-intensity air curtain), the second air shield provides auxiliary protection, and the third air shield serves as the final guarantee. The controller uses a high-performance industrial computer, integrating multi-sensor data (pressure, flow, etc.) to achieve intelligent adjustment.

[0065] Workflow: During the container positioning stage, three levels of air shields are activated sequentially (airflow velocity of the first air shield 4.5 m / s, the second air shield 3.5 m / s, and the third air shield 2.5 m / s) to form a gradient seal. During the quantitative filling stage, the system dynamically adjusts the intensity of each air shield level based on real-time pressure data (if pressure fluctuations exceed ±100 Pa, the air shields are automatically strengthened or weakened to maintain pressure balance). The separation and purification module and the pressure regulation module work together to ensure gas-solid separation and pressure balance.

[0066] Advantages and limitations: High sealing reliability and strong adaptability, but higher cost and more complex maintenance. Implementation requires calibration of the controller's parameters to match the specific powder characteristics.

[0067] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0068] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A pneumatic-based powder packaging system, characterized by, The gas screen control module, the separation and purification module, and the pressure regulating module are included. The separation and purification module is provided with a feeding port, a discharging port, and an exhaust port, wherein the feeding port is arranged at the outlet of the powder discharging pipeline, and the exhaust port is arranged between the feeding port and the discharging port. The pressure regulating module includes a pressure sensor, a positive pressure device, an exhaust pipe, and a filtering device, wherein the inlet end of the exhaust pipe is connected with the exhaust port, the outlet end is connected with the filtering device, the gas is discharged to the outside through the filtering device, and the pressure sensor and the positive pressure device are arranged on the exhaust pipe and are used for detecting pressure data and adjusting air pressure respectively. The gas screen control module includes a controller and two gas screen devices, wherein the first gas screen device is coaxially arranged between the output end of the powder discharging pipeline and the feeding port, and the second gas screen device is coaxially arranged at the discharging port and is used for generating a gas curtain barrier with adjustable strength; and the controller is used for receiving instructions and generating corresponding control signals to dynamically adjust the sealing strength of the gas curtain barrier.

2. The system of claim 1, wherein, A dustproof device is arranged at the powder outlet below the second gas screen device, and the dustproof device is connected with the controller and is configured to receive the instruction of the controller and act in the quantitative filling stage to physically seal the opening of the packaging container.

3. The system of claim 1, wherein, The gas screen device adopts a ring-shaped air knife, a ring-shaped air nozzle, or a fan-shaped nozzle structure, the inner ring diameter of which is matched with the inner diameter of the pipeline, and the gas hole is designed to ensure that the gas flow uniformly covers the entire pipeline section.

4. The system of claim 1, wherein, The separation and purification module adopts a cyclone separator, a filter cartridge dust collector, or a bag-type dust collector.

5. The system of claim 1, wherein, The positive pressure device adopts a centrifugal fan, a Roots blower, or a compressed air system.

6. The system of claim 1, wherein, At least one gas screen device is further included, and the gas screen devices are connected through the separation device, and the strength of each gas screen device gradually decreases from top to bottom.

7. A method for the pneumatic-based packaging of powders, using the system according to any one of claims 1-6, characterized in that, The method includes: S1: system initialization, the controller receives packaging instructions and enters the working mode; S2: in the container positioning stage, the controller starts the first gas screen device and the second gas screen device to form a gradient sealing barrier in response to the container positioning instruction, wherein the first gas screen device generates a main barrier, and the second gas screen device provides auxiliary protection, and the separation and purification module is started to separate the powder-containing gas flow at the same time; S3: in the quantitative filling stage, the controller confirms that the container positioning is completed, switches to the quantitative filling mode, starts the dustproof device to seal the opening of the packaging container, adjusts the gas screen device to a slightly positive pressure state, and starts the positive pressure device to maintain a positive pressure environment of the system, so that the powder is driven by the pressure and realizes filling; S4: the system pressure parameters are monitored in real time, and each module is adjusted through the controller; S5: the system is reset after the filling is completed.

8. The method of claim 7, wherein, The specific operation of the container positioning stage in step S2 includes: After the controller receives the container positioning instruction, the first gas screen device and the second gas screen device are started immediately; The first gas screen device generates a high-strength gas curtain as a main barrier, and the second gas screen device provides auxiliary protection; The separation and purification module is started synchronously to efficiently separate the powder-containing gas flow generated in the sealing process.

9. The method of claim 7, wherein, The specific operation of the quantitative filling stage in step S3 includes: After the controller confirms that the container positioning is completed, the system is switched to the quantitative filling mode; The dustproof device is started to tightly adhere to the mouth of the packaging container to form a physical seal; The air screen device is adjusted to a slightly positive pressure state, and the air flow rate is reduced to a lower level; The positive pressure device is started to maintain the system in a positive pressure environment at the pipeline conveying pressure or slightly higher; The powder flows smoothly under pressure driving to achieve accurate filling.

10. The method of claim 7, wherein, The source of the packaging instruction includes at least one of the following modes: manual instruction issued by an operator, linkage control signal issued by upstream or downstream equipment, and trigger instruction automatically generated by the controller according to preset conditions.

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