Venturi powder conveying control method based on material flow adaptively adjusting

Abstract

The present application belongs to the technical field of powder conveying, and discloses a Venturi powder conveying control method based on self-adaptive adjustment of material fluidity, which comprises the following steps: solving a parabolic relationship model of the negative pressure of a feeding port and a throat distance, and determining a reference throat distance; calculating an optimal throat distance according to the reference throat distance and material characteristics, and driving a gas inlet pipe to move to a position corresponding to the optimal throat distance; measuring the negative pressure of the feeding port in real time, and calculating a real-time material-gas ratio according to the negative pressure and a material repose angle; measuring the pressure difference of a pipeline in real time, and calculating a pressure difference change rate; determining whether a pre-blocking mode is triggered according to the pressure difference change rate and the real-time material-gas ratio; when the pre-blocking mode is triggered, calculating a backward displacement according to the pressure difference change rate and the real-time material-gas ratio, and driving the gas inlet pipe to retreat in the axial direction by the backward displacement. The present application can self-adaptively adjust the Venturi transmitter, and realizes efficient and stable material conveying.

Description

Technical Field

[0001] This invention belongs to the field of powder conveying technology, specifically relating to a Venturi powder conveying control method based on adaptive adjustment of material flowability. Background Technology

[0002] Pneumatic conveying is a technology that uses airflow within pipelines as the conveying power to achieve efficient transfer of powdery and granular materials. Due to its advantages such as good system sealing, low dust pollution, and flexible pipeline layout, it has been widely used in various industrial fields including new energy, chemical, building materials, food, and pharmaceuticals.

[0003] As the core power component of a pneumatic conveying system, the performance of the Venturi transmitter directly determines the stability and conveying efficiency of the entire system. Its working principle is as follows: High-pressure airflow from compressed air or a high-pressure blower is ejected at high speed through a nozzle, creating a negative pressure zone in the annular space between the nozzle and the throat. This negative pressure zone is connected to the feed inlet, and the pressure difference draws the material from the inlet into the mixing chamber. After thorough mixing with the high-speed airflow, the material, along with the airflow, passes through the Venturi diffuser section into the downstream material conveying pipeline, ultimately being transported to the target location.

[0004] In actual powder conveying processes, different types of materials exhibit significant differences in their physical properties. Among these, the flowability of the material (usually characterized by the angle of repose) has a decisive impact on the stability of the conveying process. Specifically, materials with excellent flowability (small angle of repose) are easily drawn in by negative pressure and are less prone to sedimentation within the pipeline, enabling stable conveying. Conversely, materials with poor flowability (larger angle of repose, such as titanium dioxide and nano-calcium carbonate) have strong interparticle adhesion and rapid settling speed, making them highly susceptible to accumulation on the inner wall of the pipeline during conveying, leading to pipe blockage. Pipe blockage not only causes production interruptions and increases manual cleaning costs but can also, in severe cases, cause pipeline wear and equipment damage, resulting in significant economic losses for enterprises.

[0005] Currently, the adjustment methods of existing Chinese chury transmitters are mostly manual or fixed-program adjustment, which have obvious technical defects: on the one hand, this type of adjustment method cannot sense the dynamic changes in material flow during the conveying process in real time and cannot adaptively adjust; on the other hand, the adjustment process usually takes "generating the maximum negative pressure" as the single objective, without combining the differences in material flow and conveying conditions for dynamic adaptation, resulting in insufficient adaptability of the conveying system to materials with poor flow, frequent pipe blockage failures, and difficulty in meeting the high-efficiency and stable conveying requirements in industrial production. Summary of the Invention

[0006] The purpose of this invention is to provide a Venturi powder conveying control method, device, equipment and storage medium based on adaptive adjustment of material flowability, which can adaptively adjust the Venturi transmitter to achieve efficient and stable material conveying.

[0007] The first aspect of this invention discloses a Venturi powder conveying control method based on adaptive adjustment of material flowability, comprising:

[0008] Solve the parabolic relationship model between the inlet negative pressure and the throat distance to determine the reference throat distance, which is the axial distance between the nozzle and the throat when the inlet negative pressure is at its maximum under no-load condition.

[0009] The optimal throat distance is calculated based on the reference throat distance and material characteristics, and the intake pipe is driven to move to the position corresponding to the optimal throat distance. The material characteristics include: material angle of repose, material particle density and material average particle size.

[0010] The negative pressure at the feed inlet is measured in real time, and the real-time material-to-air ratio is calculated based on the negative pressure at the feed inlet and the material's angle of repose.

[0011] Real-time measurement of pipeline differential pressure and calculation of pipeline differential pressure change rate; determination of whether to trigger pre-blocking mode based on pipeline differential pressure change rate and real-time material-to-air ratio; the pipeline differential pressure is the difference between pipeline pressures collected by pressure sensors installed at two target locations on the material conveying pipeline.

[0012] When the pre-blocking mode is triggered, the backward displacement is calculated based on the pipeline pressure difference change rate and the real-time material-to-gas ratio, and the air intake pipe is driven to move backward along the axial direction by the backward displacement.

[0013] In some implementations, the expression for calculating the optimal throat-mouth distance is:

[0014]

[0015] in, The optimal throat-to-mouth distance; The reference throat-mouth distance; Angle of repose for the material; The density of the material particles; To convey gas density; The average particle size of the material; The diameter of the larynx; This is a fluidity correction factor, with a value range of 0.3 to 1.5 mm / °; This is the inertia correction factor, with a value range of 5~30mm.

[0016] In some embodiments, after driving the air intake pipe to retract the specified retraction displacement along the axial direction, the method further includes: when the number of consecutive retractions of the pre-blocking mode triggered and the air intake pipe retracts exceeds a preset number, closing the discharge valve, driving the air intake pipe to move to the position corresponding to the maximum throat distance, performing pulse clearing of the air source direct blowing pipe, and after clearing the blockage, moving the air intake pipe to the position corresponding to the optimal throat distance, and restoring material conveying.

[0017] In some implementations, the expression for calculating the real-time material-to-air ratio based on the inlet negative pressure and the material's angle of repose is as follows:

[0018]

[0019] in, This refers to the real-time material-to-gas ratio. These are calibration coefficients; The feed inlet is under negative pressure; Angle of repose for the material.

[0020] In some implementations, determining the calibration coefficients includes:

[0021] Several representative materials were selected, and weighing calibration experiments were conducted on each of them to obtain the calibration coefficients of each representative material.

[0022] Based on the calibration coefficients of all representative materials, the pre-constructed relational model based on the calibration coefficients, material particle density, material average particle size, and angle of repose is solved.

[0023] Input the current material particle density, average particle size, and angle of repose into the relationship model to obtain the calibration coefficients.

[0024] In some implementations, determining whether to trigger a pre-blocking mode based on the pipeline pressure differential change rate and the real-time material-to-gas ratio includes:

[0025] Based on the real-time material-to-air ratio, airflow velocity at the throat, and material settling velocity, the dynamic threshold corresponding to the current operating condition is calculated. The expression for calculating the dynamic threshold is: ,in, For safety factors, the value ranges from 0.6 to 0.9. For real-time gas-to-material ratio, For the maximum allowable gas-to-material ratio, The airflow velocity at the throat. This refers to the settling velocity of the material.

[0026] When the rate of change of the pipeline pressure difference is greater than or equal to the dynamic threshold, the pre-blocking mode is determined to be triggered.

[0027] A second aspect of this invention discloses a Venturi powder conveying control device based on adaptive adjustment of material flowability, comprising:

[0028] The reference throat distance module is used to solve the parabolic relationship model between the feed inlet negative pressure and the throat distance to determine the reference throat distance, which is the axial distance between the nozzle and the throat when the feed inlet has the maximum negative pressure under no-load conditions.

[0029] The optimal throat distance module is used to calculate the optimal throat distance based on the reference throat distance and material characteristics, and drive the air intake pipe to move to the position corresponding to the optimal throat distance. The material characteristics include: material angle of repose, material particle density and material average particle size.

[0030] The real-time material-to-air ratio module is used to measure the negative pressure at the feed inlet in real time and calculate the real-time material-to-air ratio based on the negative pressure at the feed inlet and the angle of repose of the material.

[0031] The pre-blocking mode determination module is used to measure the pipeline pressure difference in real time and calculate the pipeline pressure difference change rate. Based on the pipeline pressure difference change rate and the real-time material-gas ratio, it determines whether to trigger the pre-blocking mode. The pipeline pressure difference is the difference between the pipeline pressure collected by pressure sensors installed at two target locations on the material conveying pipeline.

[0032] An adaptive adjustment module is used to calculate the backward displacement based on the pipeline pressure difference change rate and the real-time material-gas ratio when the pre-blocking mode is triggered, and drive the air intake pipe to move backward along the axial direction by the backward displacement.

[0033] In some embodiments, the pre-blocking mode determination module includes a dynamic threshold calculation unit. This dynamic threshold calculation unit calculates the dynamic threshold corresponding to the current operating condition based on the real-time material-to-gas ratio, the airflow velocity at the throat, and the material settling velocity. The expression for calculating the dynamic threshold is: ,in, For safety factors, the value ranges from 0.6 to 0.9. For real-time gas-to-material ratio, For the maximum allowable gas-to-material ratio, The airflow velocity at the throat. This refers to the settling velocity of the material.

[0034] A third aspect of the present invention discloses an electronic device, including a memory storing executable program code and a processor coupled to the memory; the processor calls the executable program code stored in the memory to execute the Venturi powder conveying control method based on adaptive adjustment of material flowability disclosed in the first aspect.

[0035] The fourth aspect of the present invention discloses a computer-readable storage medium storing a computer program, wherein the computer program causes a computer to execute the Venturi powder conveying control method based on adaptive adjustment of material flowability disclosed in the first aspect.

[0036] The beneficial effects of this invention are as follows: First, the optimal throat distance is calculated based on the material characteristics. The air inlet pipe is then driven to move to the optimal throat distance position to begin conveying, which enables the formation of an optimal negative pressure field within the Venturi transmitter, improving conveying stability. During conveying, the risk of blockage is assessed based on the pipeline pressure difference change rate and the real-time material-to-air ratio, ensuring the accuracy of the triggering timing. Furthermore, a mapping relationship between material characteristics and adjustment parameters is established: the retraction displacement is calculated based on the pipeline pressure difference change rate and the real-time material-to-air ratio; the air inlet pipe is driven to retract axially by this retraction displacement to adjust the throat distance, reducing the negative pressure at the inlet and thus reducing the feed rate, nipping the risk of blockage in the bud. This invention enables adaptive adjustment of the Venturi transmitter based on material characteristics and pipeline conditions, achieving efficient and stable material conveying. Attached Figure Description

[0037] The accompanying drawings illustrate specific examples of the technical solutions described in this invention and, together with the detailed embodiments, form part of the specification, serving to explain the technical solutions, principles, and effects of this invention.

[0038] Unless otherwise specified or defined, the same reference numerals in different figures represent the same or similar technical features, and different reference numerals may be used to represent the same or similar technical features.

[0039] Figure 1 This is a perspective view of the pneumatic conveying system disclosed in an embodiment of the present invention;

[0040] Figure 2 yes Figure 1 A sectional view of the front-end section;

[0041] Figure 3 This is a flowchart of a Venturi powder conveying control method based on adaptive adjustment of material flowability disclosed in an embodiment of the present invention;

[0042] Figure 4 This is a flowchart of the process for determining whether a pre-blocking mode is triggered, as disclosed in an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the Venturi powder conveying control device based on adaptive adjustment of material flowability according to an embodiment of the present invention.

[0044] Figure 6 This is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention.

[0045] Explanation of reference numerals in the attached figures:

[0046] 100. Pneumatic conveying system; 10. Feeding hopper support; 11. Feeding hopper; 12. Venturi transmitter; 13. Discharge pneumatic butterfly valve; 14. Scanning pressure sensor; 15. Air source pipe nozzle; 16. Servo module; 17. Module support; 18. Flexible tube; 19. High-pressure blower; 20. Blower base; 21. Throat; 30. Material conveying pipeline; 31. First pipeline; 32. First bend; 33. Second pipeline; 34. Second bend; 35. Third pipeline; 40. Pressure sensor; 50. Mixer. Detailed Implementation

[0047] Unless otherwise specified or defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. When combined with the technical solutions of the invention in a real-world scenario, all technical and scientific terms used herein may also have meanings corresponding to the purpose of achieving the technical solutions of the invention. The terms "first," "second," etc., used herein are merely for distinguishing names and do not represent a specific number or order. The term "and / or," as used herein, includes any and all combinations of one or more of the associated listed items.

[0048] It should be noted that when a component is considered "fixed" to another component, it can be directly fixed to the other component or there can be an intervening component; when a component is considered "connected" to another component, it can be directly connected to the other component or there can be an intervening component; when a component is considered "mounted" on another component, it can be directly mounted on the other component or there can be an intervening component; when a component is considered "placed" on another component, it can be directly placed on the other component or there can be an intervening component.

[0049] Unless otherwise specified or defined, the terms "described" or "the" as used herein refer to the technical features or technical content mentioned or described prior to the relevant section, which may be the same as or similar to the technical features or technical content mentioned herein. Furthermore, the terms "comprising" and "having," and any variations thereof, as used herein, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or apparatus.

[0050] This invention discloses a Venturi powder conveying control method based on adaptive adjustment of material flowability, which can be implemented by computer programming. The execution subject of this method can be any electronic device with data processing, instruction output, and control functions, such as a computer, laptop, or tablet computer. Alternatively, a control chip or control module embedded in the aforementioned electronic device or pneumatic conveying system can be used; this invention does not limit this. The control method provided by this invention enables automated and adaptive adjustment of the Venturi transmitter in a pneumatic conveying system, solving the technical problems of poor adaptability and easy pipe blockage caused by existing manual or fixed-program adjustments, thus improving the stability and adaptability of the conveying system. Specifically, the pneumatic conveying system mainly uses several feeding hoppers, and different powders are sent to a mixer via Venturi transmitters for mixing to prepare a finished slurry.

[0051] To facilitate understanding of the present invention, specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

[0052] The pneumatic conveying system 100 of this invention embodiment is as follows: Figure 1 , Figure 2As shown, the system specifically includes: a feeding hopper bracket 10 installed on the ground, with a feeding hopper 11 fixed to the feeding hopper bracket 10. A Venturi transmitter 12 is installed below the feeding hopper 11, and a discharge pneumatic butterfly valve 13 is installed between the Venturi transmitter 12 and the feeding hopper 11. The discharge pneumatic butterfly valve 13 is used to control the feeding of material from the feeding hopper 11 to the Venturi transmitter 12. A scanning pressure sensor 14 is installed on the side of the Venturi transmitter 12. This scanning pressure sensor 14 is used to detect the negative pressure value at the inlet of the Venturi transmitter 12 in real time. An air supply pipe nozzle 15 is installed on the left side of the Venturi transmitter 12, and a sealing ring is installed on the air supply pipe nozzle 15 to ensure sealing performance. The air supply pipe nozzle 15 is installed on a servo module 16, and the servo module 16 and module bracket 17 are fixedly connected. The module bracket 17 is fixedly installed on the ground. The left side of the air source pipe nozzle 15 is sealed to one end of the elastic tube 18, and the other end of the elastic tube 18 is connected to the blower port of the high-pressure blower 19. The high-pressure blower 19 is fixedly assembled with the blower base 20, which is fixedly installed on the ground. The Venturi transmitter 12 has a throat 21, and the axial distance between the throat 21 and the nozzle orifice of the air source pipe nozzle 15 is the throat-nozzle distance. The right side of the Venturi transmitter 12 is connected to a material conveying pipe 30, which has two bends that divide the material conveying pipe 30 into: a first pipe 31, a first bend 32, a second pipe 33, a second bend 34, and a third pipe 35. Pressure sensors 40 are installed on the first pipe 31, the second pipe 33, and the third pipe 35. The difference between the pipe pressure detected by the pressure sensor 40 on the first pipe 31 and the pipe pressure detected by the pressure sensor 40 on the second pipe 33 or the third pipe 35 is the pipe pressure differential. The end of the material conveying pipe 30 is connected to the mixer 50 to send the conveyed material into the mixer 50 for further processing.

[0053] like Figure 3 As shown, the pneumatic conveying system implements a Venturi powder conveying control method based on adaptive adjustment of material flowability, and the specific steps for achieving automated and adaptive adjustment of the Venturi transmitter include:

[0054] Step S100: Solve the parabolic relationship model between the inlet negative pressure and the throat distance to determine the reference throat distance, where the reference throat distance is the axial distance between the nozzle and the throat corresponding to the maximum negative pressure value of the inlet under no-load conditions.

[0055] Under no-load conditions, by adjusting the relative distance between the nozzle and the throat, the negative pressure at the feed inlet changes in a parabolic pattern that first increases and then decreases with the change in the nozzle-throat distance. The peak of the curve corresponds to the position of the negative pressure peak, and the axial distance between the nozzle and the throat corresponding to this negative pressure peak is the reference nozzle-throat distance.

[0056] Specifically, the parabolic relationship between the inlet negative pressure and the throat distance can be expressed as:

[0057]

[0058] in, The distance between the larynx and the mouth is The negative pressure at the feed inlet at that time, in kPa; This is the maximum negative pressure value, in kPa. The distance between the nozzle and the point of maximum negative pressure is in mm. The curvature coefficient is expressed in kPa / mm. 2 For conventional powder conveying Venturi transmitters, the value of α ranges from 0.05 to 0.10 kPa / mm². The larger the α, the steeper the curve, the narrower the optimal operating point range, and the higher the requirement for adjustment precision; the smaller the α, the smoother the curve, and the better the adjustment tolerance.

[0059] The process of solving the parabolic relationship is as follows: The servo motor drives the intake pipe (which in turn drives the air source pipe nozzle) from the minimum throat distance. Initially, move gradually to the maximum throat-mouth distance using preset step distances. During the movement of the intake manifold, scanning pressure sensors installed on the side of the venturi transmitter collect and record the distance position of each nozzle in real time. The corresponding negative pressure value at the feed inlet Multiple sets of throat-mouth distance-negative pressure pair data were generated. , Based on the collected multiple sets ( , The data was used to fit a parabolic curve between the inlet negative pressure and the throat distance using a data fitting algorithm. This curve was then used to determine the parameter corresponding to the vertex of the parabola: the maximum negative pressure value at the inlet under no-load conditions. and the maximum negative pressure value Corresponding throat-mouth distance (i.e., the reference throat-mouth distance).

[0060] Step S200: Calculate the optimal throat distance based on the reference throat distance and material characteristics, and drive the air intake pipe to move to the position corresponding to the optimal throat distance. The material characteristics include: material angle of repose, material particle density, and material average particle size.

[0061] The root cause of blockages in Venturi conveyors is that the velocity of the material entering the pipe is lower than the minimum velocity required for conveying, leading to sedimentation. Two factors determine this minimum velocity: static factors (angle of repose)... This characterizes the material's viscosity, internal friction, and bridging ability. A larger angle of repose makes it more difficult for the material to smoothly enter the feed inlet from the hopper; dynamic factors ( This characterizes the distance a material needs to travel to reach the airflow velocity once it enters the airflow; the heavier and larger the material, the longer the acceleration distance. To ensure the material reaches sufficient velocity before entering the main duct, a sufficiently long mixing and acceleration zone must be provided. The length of this mixing and acceleration zone is the optimal throat distance. Therefore, the optimal throat-mouth distance By static correction ( ) and dynamic correction ( (To be decided jointly)

[0062] Specifically, the formula for calculating the optimal throat-mouth distance is:

[0063]

[0064] in, The optimal throat-to-mouth distance typically ranges from 10 to 80 mm. The reference throat-mouth distance typically ranges from 5 to 20 mm. The angle of repose of the material, typically ranging from 20° to 60°; This refers to the particle density of the material, typically ranging from 500 to 3000 kg / m³. To convey gas density; This represents the average particle size of the material, typically ranging from 0.001 to 3 mm. This refers to the diameter of the trachea, typically ranging from 20 to 80 mm. This is a flowability correction factor, typically ranging from 0.3 to 1.5 mm / °. This is the inertia correction factor, and its value range is usually 5~30mm.

[0065] Material parameters: , , Reference throat distance Substituting these values ​​into the above formula, the optimal throat-mouth distance can be calculated. Then, the servo motor is started, and the servo motor drives the air intake pipe (which in turn moves the air source pipe nozzle) axially along the delivery pipeline until the air intake pipe moves the nozzle to the optimal throat distance. At the corresponding position, the throat distance is precisely adjusted, and then material conveying begins. The reason why this embodiment abandons the reference throat distance and chooses the position of the optimal throat distance is that the feed rate is the largest at the point of maximum negative pressure. For materials with poor flowability, this is precisely the working condition that is most prone to pipe blockage. The optimal throat distance is equivalent to the best value under the current material parameters, which can create the optimal negative pressure field in the Venturi transmitter, sacrificing some suction power in exchange for conveying stability.

[0066] Setting parameters: Pipe inner diameter =40mm, air density =1.2kg / m3, reference throat distance =20mm, coefficient , =15mm, experiments were conducted on various materials, and the experimental results are shown in Table 1.

[0067] Table 1. Results of the Optimal Throat-Mouth Distance Experiment

[0068]

[0069] As can be seen from Table 1, the relative error between the predicted and measured values ​​of the optimal throat distance for each material is controlled within ±3%. The calculation model has high fitting accuracy, can adapt to powder materials with different physical properties, and can accurately calculate the optimal throat distance corresponding to the working conditions, meeting the engineering application requirements of adaptive adjustment.

[0070] Step S300: Measure the negative pressure at the feed inlet in real time, and calculate the real-time material-to-air ratio based on the negative pressure at the feed inlet and the material's angle of repose;

[0071] During material conveying, the negative pressure at the feed inlet is measured in real time, and then the real-time material-to-air ratio is calculated based on the negative pressure at the feed inlet and the material's angle of repose. The real-time material-to-air ratio characterizes the airflow's ability to carry materials. If the real-time material-to-air ratio is too high, the airflow's carrying capacity is insufficient, which can easily lead to material settling.

[0072] The specific calculation expression is as follows:

[0073]

[0074] in, This is the real-time material-to-air ratio, expressed in kg (powder) / kg (air). This is the calibration factor, with units of kg·° / (kPa·kg). The negative pressure at the feed inlet is measured in real time, and the unit is kPa; Angle of repose of the material, in degrees.

[0075] Calibration using standard materials Real-time material-to-gas ratio experiments were conducted on various materials to verify the results, which are shown in Table 2.

[0076] Table 2. Results of Real-Time Material-to-Gas Ratio Experiment

[0077]

[0078] As can be seen from Table 2, the prediction error of the real-time material-to-gas ratio calculation formula is within ±8%, which meets the engineering requirements.

[0079] For calibration coefficients This embodiment does not require individual calibration for each material, but rather establishes material property parameters and... The mapping relationship enables one-time calibration and universal adaptation. The specific process for determining the calibration coefficients is as follows:

[0080] First, select several representative materials, such as 3-5 representative materials (covering low to high density, fine powder to granules, and small to large angle of repose), and conduct weighing calibration experiments on each to obtain the calibration coefficients for each representative material. Based on the calibration coefficients of all representative materials, solve the pre-constructed relationship model based on the calibration coefficients, material particle density, average particle size, and angle of repose. The expression of the relationship model is as follows: The solution method can be regression analysis. The parameters in the relational model are determined through the solution; then the particle density of the current material is calculated. Average particle size of materials And Anse Col By inputting the relational model, the calibration coefficients can be obtained by solving it. No recalibration is required.

[0081] Step S400: Measure the pipeline differential pressure in real time and calculate the pipeline differential pressure change rate. Determine whether to trigger the pre-blocking mode based on the pipeline differential pressure change rate and the real-time material-to-gas ratio. The pipeline differential pressure is the difference between the pipeline pressure collected by the pressure sensors installed at two target locations on the material conveying pipeline.

[0082] Pipeline pressure difference This is the difference between the pipe pressure detected by the pressure sensor on the first pipe and the pipe pressure detected by the pressure sensor on the second or third pipe. The rate of change of pressure difference is the rate of change of pipe pressure difference over time, which can be specifically expressed as... The differential pressure change rate reflects the tendency of material to accumulate in the pipeline; an increase in the differential pressure change rate indicates an increased risk of material accumulation. When the differential pressure change rate exceeds a preset threshold, it indicates that pipe blockage is imminent, and early intervention can be implemented to prevent pipe blockage failure.

[0083] This embodiment not only adaptively adjusts the throat distance based on material parameters, but also adaptively calculates a threshold for comparison with the differential pressure change rate based on the current operating conditions. That is, when determining whether to trigger the pre-blocking mode, the differential pressure change rate is compared with a dynamic threshold related to the current operating conditions to ensure the accuracy of the triggering timing.

[0084] Specifically, such as Figure 4 As shown, the steps for determining whether to trigger the pre-blocking mode based on the pipeline pressure difference change rate and the real-time material-to-gas ratio include:

[0085] Step S410: Calculate the dynamic threshold corresponding to the current working condition based on the real-time material-to-air ratio, airflow velocity at the throat, and material settling velocity;

[0086] The expression for calculating the dynamic threshold is: ,in, The safety factor ranges from 0.6 to 0.9. This is the real-time gas-to-material ratio, in kg / kg. The maximum permissible gas-to-material ratio is obtained from a table based on the angle of repose; The airflow velocity at the throat is measured in m / s and is calculated from the gas flow meter or the gas source pressure. The settling velocity of the material is expressed in m / s, using an empirical formula. Calculations show that This is the drag coefficient.

[0087] Step S420: When the pipeline pressure difference change rate is greater than or equal to the dynamic threshold, the pre-blocking mode is triggered.

[0088] The formula for comparing the pipeline differential pressure change rate with the dynamic threshold is:

[0089]

[0090] in, The pipeline pressure differential change rate is expressed in kPa / s, measured in real time and calculated every 0.2s. This is a dynamic threshold. When the rate of change of pipeline pressure difference exceeds the dynamic threshold, the pre-blocking mode is triggered, which means the pipeline will be blocked, and an adjustment action needs to be triggered immediately.

[0091] / The larger the value, the closer the current material-to-gas ratio is to its limit, the easier it is to clog, and the lower the dynamic threshold. / The smaller the value, the slower the airflow velocity relative to the settling velocity, the weaker the anti-blockage ability, and the lower the dynamic threshold.

[0092] Setting parameters: =0.75, airflow velocity in the pipeline Experimental tests were conducted on different powders, and the results of the pre-blocking mode triggering are shown in Table 3. The experimental results show that when the measured differential pressure change rate in the pipeline is less than the dynamic threshold, the system does not trigger the pre-blocking mode; when the measured differential pressure change rate is greater than or equal to the dynamic threshold, the system can accurately identify the material accumulation trend and reliably trigger the pre-blocking mode. The experiments covered a variety of typical powder materials in the new energy and chemical fields, and the judgment logic showed good consistency, effectively verifying the rationality and engineering practical value of the pre-blocking judgment formula.

[0093] Table 3: Experimental Results of Triggered Pre-blocking Mode

[0094]

[0095]

[0096] Step S500: When the pre-blocking mode is triggered, the backward displacement is calculated based on the pipeline pressure difference change rate and the real-time material-to-gas ratio, and the air intake pipe is driven to move backward along the axial direction by the backward displacement.

[0097] When the pre-blocking mode is triggered, based on the real-time collected pipeline pressure difference change rate and real-time material-to-air ratio, the required backward displacement of the air inlet pipe is calculated. This is determined by the servo motor driving the air inlet pipe (which in turn drives the air source pipe nozzle) to retract axially along the conveying pipeline by the required backward displacement distance, achieving dynamic adjustment during the conveying process. (Calculation of backward displacement amount) The specific formula is: ,in, For adjustment coefficients, The value range is 0.5 to 3.0 mm·s / kPa.

[0098] This adjustment effectively increases the throat distance, reduces the material-to-air ratio, optimizes the negative pressure field distribution inside the Venturi transmitter, and enhances the airflow ejection velocity and carrying capacity. This, in turn, accelerates the material conveying speed within the pipeline, inhibits material settling and accumulation on the pipeline wall, proactively prevents pipe blockage, and ensures the continuity and stability of the powder conveying process. Existing conveying systems, however, cannot establish a mapping relationship between material characteristics and adjustment parameters. Operators must repeatedly try and fail when changing materials, resulting in low efficiency and difficulty in guaranteeing effectiveness.

[0099] In existing conveying systems, when the pipeline is blocked or about to be blocked, the existing Venturi device cannot actively intervene. Usually, the only solution is to manually clean the blockage or use external purging after stopping the machine, which affects production efficiency. Therefore, this embodiment, after driving the air inlet pipe to retract the specified retraction displacement along the axial direction, also includes: if it is determined that the pre-blocking mode has not been triggered after the air inlet pipe retraction, then normal conveying is resumed; if it is determined that the pre-blocking mode has been triggered and the number of consecutive retractions of the air inlet pipe exceeds a preset number, for example, if the pre-blocking mode is still triggered after driving the air inlet pipe to retract 3 times, then the unblocking mode is entered: the discharge valve is closed, the servo motor drives the air inlet pipe to move to the position corresponding to the maximum throat distance, and the air source is directly blown into the pipeline for pulse unblocking. After unblocking is completed, the air inlet pipe moves to the position corresponding to the optimal throat distance, and material conveying is resumed.

[0100] The pneumatic conveying system in this embodiment operates as follows: After system startup, the servo motor drives the nozzle of the air supply pipe to move back and forth, while simultaneously scanning the pressure sensor to collect the negative pressure at the feed inlet in real time. The controller automatically finds the position where the maximum negative pressure is generated as the reference throat distance. After the user inputs parameters such as the angle of repose, density, and particle size of the material, the controller automatically calculates the optimal throat distance based on these material parameters and drives the air inlet pipe to move to the optimal throat distance position to start conveying. During the conveying process, the system continuously monitors the values ​​of the pressure sensors on the first pipe and the second or third pipe, automatically calculates the pipe pressure difference, calculates the current material-to-air ratio in real time, and judges the risk of blockage by the rate of change of the pipe pressure difference. When the rate of increase of the pipe pressure difference exceeds the dynamic threshold related to the current operating conditions, it is determined that the pipe is about to be blocked. The controller immediately instructs the servo motor to retract the air inlet pipe a certain distance, reducing the negative pressure at the feed inlet and thus reducing the feed rate, nipping the risk of blockage in the bud. If the pressure differential continues to rise after repeated adjustments, it indicates a pipe blockage. The system automatically closes the discharge pneumatic butterfly valve and retracts the air inlet pipe to its limit position, using direct airflow for pulse clearing. After clearing the blockage, the system automatically resets and resumes conveying. Throughout the process, the system adaptively adjusts based on material characteristics and pipeline conditions, requiring no manual intervention.

[0101] In summary, this embodiment first automatically calculates the optimal throat distance based on material characteristics, driving the inlet pipe to the optimal throat distance position to begin conveying. This creates an optimal negative pressure field within the Venturi transmitter, improving conveying stability. During conveying, the risk of blockage is assessed based on the rate of change of pipeline pressure difference and the real-time material-to-air ratio, ensuring accurate triggering timing. Furthermore, the backward displacement is calculated based on the rate of change of pipeline pressure difference and the real-time material-to-air ratio, adjusting the throat distance to reduce the negative pressure at the inlet, decrease the feed rate, and nip the risk of blockage in the bud. Therefore, the Venturi transmitter can adaptively adjust based on material characteristics and pipeline conditions, achieving efficient and stable material conveying.

[0102] like Figure 5 As shown, based on the above-mentioned Venturi powder conveying control method based on adaptive adjustment of material flowability, this embodiment of the invention discloses a Venturi powder conveying control device based on adaptive adjustment of material flowability, comprising:

[0103] The reference throat distance module 600 is used to solve the parabolic relationship model between the feed inlet negative pressure and the throat distance, and to determine the reference throat distance, which is the axial distance between the nozzle and the throat when the feed inlet has the maximum negative pressure under no-load conditions.

[0104] The optimal throat distance module 610 is used to calculate the optimal throat distance based on the reference throat distance and material characteristics, including: material angle of repose, material particle density and material average particle size, and drive the air inlet pipe to move to the position corresponding to the optimal throat distance.

[0105] The real-time material-to-air ratio module 620 is used to measure the negative pressure at the feed inlet in real time and calculate the real-time material-to-air ratio based on the negative pressure at the feed inlet and the material's angle of repose.

[0106] The pre-blocking mode determination module 630 is used to measure the pipeline pressure difference in real time and calculate the pipeline pressure difference change rate. Based on the pipeline pressure difference change rate and the real-time material-gas ratio, it determines whether to trigger the pre-blocking mode. The pipeline pressure difference is the difference between the pipeline pressure collected by pressure sensors installed at two target locations on the material conveying pipeline.

[0107] The adaptive adjustment module 640 is used to calculate the backward displacement based on the pipeline pressure difference change rate and the real-time material-gas ratio when the pre-blocking mode is triggered, and drive the air intake pipe to move backward along the axial direction by the backward displacement.

[0108] In some embodiments, the pre-blocking mode determination module includes a dynamic threshold calculation unit. This dynamic threshold calculation unit calculates the dynamic threshold corresponding to the current operating condition based on the real-time material-to-gas ratio, the airflow velocity at the throat, and the material settling velocity. The expression for calculating the dynamic threshold is: ,in, For safety factors, the value ranges from 0.6 to 0.9. For real-time gas-to-material ratio, The maximum permissible gas-to-material ratio is obtained from a table based on the angle of repose. The airflow velocity at the throat. This refers to the settling velocity of the material.

[0109] like Figure 6 As shown, an embodiment of the present invention discloses an electronic device, including a memory 401 storing executable program code and a processor 402 coupled to the memory 401;

[0110] The processor 402 calls the executable program code stored in the memory 401 to execute the Venturi powder conveying control method based on adaptive adjustment of material flowability described in the above embodiments.

[0111] This invention also discloses a computer-readable storage medium storing a computer program that causes a computer to execute the Venturi powder conveying control method based on adaptive adjustment of material flowability described in the above embodiments.

[0112] The purpose of the above embodiments is to reproduce and derive the technical solution of the present invention by way of example, and to fully describe the technical solution, purpose and effect of the present invention. The purpose is to enable the public to have a more thorough and comprehensive understanding of the disclosure of the present invention, and not to limit the scope of protection of the present invention.

[0113] The above embodiments are not an exhaustive list based on the present invention, and there may be many other embodiments not listed. Any substitutions and improvements made without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A Venturi powder conveying control method based on adaptive adjustment of material flowability, characterized in that, include: Solve the parabolic relationship model between the inlet negative pressure and the throat distance to determine the reference throat distance, which is the axial distance between the nozzle and the throat when the inlet negative pressure is at its maximum under no-load condition. The optimal throat distance is calculated based on the reference throat distance and material characteristics, and the intake pipe is driven to move to the position corresponding to the optimal throat distance. The material characteristics include: material angle of repose, material particle density and material average particle size. The negative pressure at the feed inlet is measured in real time, and the real-time material-to-air ratio is calculated based on the negative pressure at the feed inlet and the material's angle of repose. Real-time measurement of pipeline differential pressure and calculation of pipeline differential pressure change rate; determination of whether to trigger pre-blocking mode based on pipeline differential pressure change rate and real-time material-to-air ratio; the pipeline differential pressure is the difference between pipeline pressures collected by pressure sensors installed at two target locations on the material conveying pipeline. When the pre-blocking mode is triggered, the backward displacement is calculated based on the pipeline pressure difference change rate and the real-time material-to-gas ratio, and the air intake pipe is driven to move backward along the axial direction by the backward displacement. The expression for calculating the optimal throat-to-mouth distance is: in, The optimal throat-to-mouth distance; The reference throat-mouth distance; Angle of repose for the material; The density of the material particles; To convey gas density; The average particle size of the material; The diameter of the larynx; This is a fluidity correction factor, with a value range of 0.3 to 1.5 mm / °; This is the inertia correction factor, with a value range of 5~30mm; The expression for calculating the real-time material-to-air ratio based on the inlet negative pressure and the material's angle of repose is as follows: in, This refers to the real-time material-to-gas ratio. These are calibration coefficients; The feed inlet is under negative pressure; Determining whether to trigger the pre-blocking mode based on the pipeline pressure difference change rate and the real-time material-to-gas ratio includes: Based on the real-time material-to-air ratio, airflow velocity at the throat, and material settling velocity, the dynamic threshold corresponding to the current operating condition is calculated. The expression for calculating the dynamic threshold is: ,in, For safety factors, the value ranges from 0.6 to 0.

9. For the maximum allowable feed-to-gas ratio, The airflow velocity at the throat. This refers to the settling velocity of the material. When the rate of change of the pipeline pressure difference is greater than or equal to the dynamic threshold, the pre-blocking mode is determined to be triggered.

2. The Venturi powder conveying control method based on adaptive adjustment of material flowability as described in claim 1, characterized in that, After the intake pipe is driven to retract axially by the specified retraction displacement, the process further includes: when the number of consecutive retractions of the pre-blocking mode triggered and the intake pipe is driven to retract exceeds a preset number, the discharge valve is closed, the intake pipe is driven to move to the position corresponding to the maximum throat distance, the air source is directly blown into the pipeline for pulse clearing, and after the clearing is completed, the intake pipe is moved to the position corresponding to the optimal throat distance to restore material conveying.

3. The Venturi powder conveying control method based on adaptive adjustment of material flowability as described in claim 1, characterized in that, Determining the calibration coefficients includes: Several representative materials were selected, and weighing calibration experiments were conducted on each of them to obtain the calibration coefficients of each representative material. Based on the calibration coefficients of all representative materials, the pre-constructed relational model based on the calibration coefficients, material particle density, material average particle size, and angle of repose is solved. Input the current material particle density, average particle size, and angle of repose into the relationship model to obtain the calibration coefficients.

4. A Venturi powder conveying control device based on adaptive adjustment of material flowability, used to execute the Venturi powder conveying control method based on adaptive adjustment of material flowability as described in any one of claims 1-3, characterized in that, include: The reference throat distance module is used to solve the parabolic relationship model between the feed inlet negative pressure and the throat distance to determine the reference throat distance, which is the axial distance between the nozzle and the throat when the feed inlet has the maximum negative pressure under no-load conditions. The optimal throat distance module is used to calculate the optimal throat distance based on the reference throat distance and material characteristics, and drive the air intake pipe to move to the position corresponding to the optimal throat distance. The material characteristics include: material angle of repose, material particle density and material average particle size. The real-time material-to-air ratio module is used to measure the negative pressure at the feed inlet in real time and calculate the real-time material-to-air ratio based on the negative pressure at the feed inlet and the angle of repose of the material. The pre-blocking mode determination module is used to measure the pipeline pressure difference in real time and calculate the pipeline pressure difference change rate. Based on the pipeline pressure difference change rate and the real-time material-gas ratio, it determines whether to trigger the pre-blocking mode. The pipeline pressure difference is the difference between the pipeline pressure collected by pressure sensors installed at two target locations on the material conveying pipeline. An adaptive adjustment module is used to calculate the backward displacement based on the pipeline pressure difference change rate and the real-time material-gas ratio when the pre-blocking mode is triggered, and drive the air intake pipe to move backward along the axial direction by the backward displacement.

5. The Venturi powder conveying control device based on adaptive adjustment of material flowability as described in claim 4, characterized in that, The pre-blocking mode determination module includes a dynamic threshold calculation unit, which is used to calculate the dynamic threshold corresponding to the current working condition based on the real-time material-to-gas ratio, the airflow velocity at the throat, and the material settling velocity.

6. An electronic device, characterized in that, It includes a memory storing executable program code and a processor coupled to the memory; the processor calls the executable program code stored in the memory to execute the Venturi powder conveying control method based on adaptive adjustment of material flowability as described in any one of claims 1-3.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program causes a computer to perform the Venturi powder conveying control method based on adaptive adjustment of material flowability as described in any one of claims 1-3.

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