Bulk grain anti-breaking and anti-classification device and method based on gas-solid coupling and elastic classification

Abstract

The application belongs to the technical field of grain storage equipment, and relates to a bulk grain anti-breaking and anti-classification device and method based on gas-solid coupling and elastic classification. The device comprises a static multi-stage flow divider, a pneumatic auxiliary unit and a dynamic adjustment system. The static multi-stage flow divider is arranged directly below the feed inlet of the warehouse top and is used for preliminarily dividing the bulk grain entering the warehouse body. The pneumatic auxiliary unit is arranged on the static multi-stage flow divider and outputs controlled airflow to form pneumatic disturbance to inhibit the classification trend of the bulk grain. The dynamic adjustment system is used for real-time monitoring of the bulk grain state and dynamic adjustment of the flow dividing parameters. The application reduces the wear of mechanical parts through static multi-stage flow dividing and pneumatic auxiliary control, and realizes buffer flow guiding by using the warehouse body structure, thereby significantly reducing the bulk grain breaking risk. The particle size sensor is introduced to dynamically optimize the flow dividing ratio and effectively inhibit the classification trend. Meanwhile, the elastic buffer coating is adopted to reduce the particle collision energy, thereby improving the uniformity and integrity of the bulk grain.

Description

Technical Field

[0001] This application belongs to the technical field of grain storage equipment, and in particular relates to a device and method for preventing breakage and grading of bulk grain based on gas-solid coupling and elastic grading. Background Technology

[0002] In grain storage and bulk grain receiving operations, common feeding methods mainly include rotary grain distributors, fixed chute feeding, and the central grain dropping method at the top of the silo. However, existing feeding technologies have gradually revealed a series of insurmountable problems in long-term application. First, traditional rotary grain distributors usually rely on mechanical rotating parts to achieve circumferential feeding. Their reverse feeding system also requires additional lifting or swinging mechanisms, which not only makes the structure complex and maintenance frequent, but also occupies a significant amount of space inside or on top of the silo, making it difficult to adapt to small or modified storage facilities. Second, these devices generally rely on fixed feeding paths; for example, the chute angle or trajectory is not adjustable, making it impossible to adaptively adjust to the differences in density, particle size, and aerodynamic behavior of different grain varieties, making grading phenomena more prominent under complex grain conditions.

[0003] Furthermore, traditional chutes are mostly made of metal, which can easily cause particle breakage during the high-speed impact of falling bulk grain. This reduces grain quality and increases dust content, affecting ventilation and subsequent processing within the silo. A more significant problem is that most existing silo top-feeding methods use a center-feeding model. During free fall, the bulk grain is affected by gas-solid separation, causing fine particles, dust, and broken material to accumulate in the center of the silo. Over time, this creates a high-impurity and high-moisture accumulation zone in the central area, significantly increasing the risk of mold, clumping, and poor storage conditions.

[0004] In summary, how to simultaneously reduce breakage rate, suppress grading, and improve impurity distribution during the bulk grain storage process, and enhance the adaptability and controllability of the distribution process, has become an urgent technical problem to be solved. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this application provides a device and method for preventing breakage and grading of bulk grain based on gas-solid coupling and elastic grading. By setting a static multi-stage diverter and a pneumatic auxiliary unit on the bulk grain falling path, the falling state of the bulk grain is actively controlled, making it difficult for fine particles to agglomerate and for coarse particles to impact at high speed. At the same time, by dynamically adjusting the particle size distribution in real time through a system, the operating parameters can be automatically adjusted, which can quickly complete the diversion, uniform distribution and grading suppression of bulk grain, and significantly improve the material integrity and uniformity of receiving materials during the falling process in the silo.

[0006] This application provides a bulk grain anti-breakage and anti-grading device based on gas-solid coupling and elastic grading, including a static multi-stage diverter, a pneumatic auxiliary unit, and a dynamic adjustment system.

[0007] A static multi-stage diverter is located directly below the feed inlet on the top of the silo and is used to initially divert the bulk grain entering the silo. The static multi-stage diverter includes multiple conical guide hoods, which are fixedly installed along the central axis of the feed inlet to initially guide the falling bulk grain and cause it to diffuse radially. Each conical guide hood is equipped with a diverting plate to further divide the radially diffused bulk grain flow into multiple independent flow streams. Each diverting plate is connected to a miniature electric push rod, which is used to drive the opening and closing of the diverting plate.

[0008] The pneumatic auxiliary unit is arranged on the static multi-stage distributor and outputs controlled airflow to form pneumatic disturbance to suppress the grading trend of bulk grain. The pneumatic auxiliary unit includes multiple adjustable airflow nozzles arranged at intervals on the conical guide shroud. The adjustable airflow nozzles are connected to the air source system through pipelines equipped with electromagnetic proportional valves.

[0009] The dynamic adjustment system is electrically connected to the static multi-stage diverter and the pneumatic auxiliary unit, respectively, for real-time monitoring of the bulk grain status and dynamic adjustment of the diversion parameters. The dynamic adjustment system includes a laser particle size analyzer and a controller. The laser particle size analyzer is installed on the inner side wall of the silo and is used to monitor the particle size distribution and position information of the falling bulk grain in real time. The controller is connected to the laser particle size analyzer, the electromagnetic proportional valve, and the micro electric push rod. The controller is configured to: adjust the opening of the electromagnetic proportional valve according to the particle size distribution and position information of the bulk grain to adjust the jet pressure of the adjustable airflow nozzle, and adjust the extension and retraction length of the micro electric push rod to adjust the opening and closing of the diverter plate.

[0010] In some embodiments, the conical fairing is arranged in an axisymmetric inverted conical structure; the multiple flow dividers are arranged in a spiral involute.

[0011] In some embodiments, the surfaces of the diverter and the conical guide vane are coated with an elastic buffer coating to reduce the impact velocity of the bulk grain and absorb some of the impact kinetic energy.

[0012] In some embodiments, the outlet direction of the adjustable airflow nozzle is inclined relative to the trajectory of the falling grain.

[0013] This application also provides a method for preventing breakage and grading of bulk grain based on gas-solid coupling and elastic grading, used in the bulk grain anti-breakage and anti-grading device described above, comprising the following steps:

[0014] The type of bulk grain to be processed and the preset processing flow rate are obtained. The corresponding grading and inhibition coefficients are retrieved from the preset grain parameter library, and the initial airflow pressure and the initial opening and closing angle of the diverter are set accordingly.

[0015] Adjust the diverter to the initial opening angle and spray the inclined airflow at the initial airflow pressure through the adjustable airflow nozzle to pre-form an air cushion resistance layer, so as to drive fine particles to diffuse in the circumferential direction when the loose grain falls and inhibit the centripetal aggregation of impurities.

[0016] The bulk grain is controlled to fall from the top feed inlet of the silo, and the conical guide hood diffuses the falling bulk grain radially, so that the bulk grain flow is distributed in an umbrella shape;

[0017] The diversion plate evenly divides the diffused bulk grain flow into multiple streams, completing the automatic circumferential diversion of the bulk grain and ensuring that the streams cover the preset coverage area of ​​the silo cross-section.

[0018] During the falling of the bulk grain, the laser particle size analyzer collects particle size distribution data and location information in real time. When it detects that the centripetal aggregation of fine particles exceeds the allowable range, it triggers a grading warning and calculates the current grading deviation value in combination with the grading inhibition coefficient.

[0019] Determine whether the deviation value exceeds the preset grading threshold: if it does not exceed the threshold, maintain the current operating parameters and continue to perform the bulk grain diversion operation; if it exceeds the threshold, adjust the airflow pressure of the airflow nozzle and the opening and closing angle of the diverter plate according to the degree of deviation, and verify the adjustment effect in real time until the grading deviation value drops below the grading threshold.

[0020] In some embodiments, the formula for calculating the hierarchical inhibition coefficient is:

[0021]

[0022] in, The hierarchical inhibition coefficient; Due to differences in particle settling velocity; This represents the normalized maximum value of the difference in particle settling velocity; This is the corrected critical airflow velocity; This is the normalized maximum value of the corrected critical airflow velocity; As the weight of the difference in particle settling velocity, The weight is the critical airflow velocity. The weight of the breakage sensitivity coefficient, , , Determined based on the characteristics of the grain variety, meeting the requirements + + =1; The crushing sensitivity coefficient, with a value range of 0–1, represents the degree of sensitivity to crushing of bulk grain.

[0023] In some embodiments, the method for determining whether the material flow covers a preset coverage area is as follows:

[0024] Multiple virtual monitoring points are set at equal angular intervals within the preset coverage area. The controller maps the material flow to each virtual monitoring point based on the data fed back by the laser particle size analyzer, and calculates the receiving intensity by combining the number of loose grain particles passing through each monitoring point per unit time and their particle size data.

[0025] The material receiving intensity of each virtual monitoring point is compared with the preset material receiving intensity threshold. When the proportion of virtual monitoring points that reach the preset threshold to all monitoring points is not less than the set proportion, the coverage condition is determined to be met.

[0026] The difference in material receiving intensity between virtual monitoring points that have reached the preset material receiving threshold is calculated. When the difference does not exceed the preset difference, the material receiving uniformity condition is determined to be met.

[0027] When both the coverage rate condition and the material receiving uniformity condition are met, it is determined that the material flow has covered the preset coverage area; otherwise, it is determined that it does not meet the standard.

[0028] In some embodiments, the method for calculating the strength of the material is as follows:

[0029] In time interval Inside, statistical monitoring points First Number of particles of different sizes passing through ,in: Indicates particle size level; Indicates the monitoring point number;

[0030] The monitoring points are calculated using the following formula. The strength of the material at the point : ,in, This refers to the bulk grain particle shape coefficient. The true density of bulk grain retrieved from the grain type parameter database; For the first batch of bulk grain The particle size of particles of different sizes; The total number of bulk grain particle size classes;

[0031] The total material intensity is obtained by summing the material intensity at all monitoring points.

[0032] In some embodiments, the method for calculating the grading deviation value is as follows:

[0033] The collected particle size distribution data were divided into fine, medium, and coarse particle sizes according to particle size.

[0034] The cross-section of the silo is divided into an inner ring area, a middle ring area, and an outer ring area.

[0035] Based on particle size distribution data, calculate the mass percentages of fine, medium, and coarse particles in the entire silo flow and use them as the ideal mass percentages for each zone.

[0036] Calculate the deviation between the actual mass percentage and the ideal mass percentage for each particle size within each region, and use the weighted sum of squares of all deviations as the final classification deviation value.

[0037] In some embodiments, the above-mentioned method for preventing breakage and grading of bulk grain further includes:

[0038] After completing the bulk grain diversion operation for the current batch, the operating parameters and particle size distribution data are stored in the grain parameter database.

[0039] Based on the above solutions, the bulk grain anti-breakage and anti-grading device and method based on gas-solid coupling and elastic grading in this embodiment of the application reduces wear on mechanical parts through a combination of static multi-stage diversion and pneumatic-assisted regulation, and utilizes the silo structure to achieve buffering and guiding, significantly reducing the risk of bulk grain breakage; the introduction of particle size sensors for real-time feedback adjustment dynamically optimizes the diversion ratio, effectively suppressing grading trends; and the use of an elastic buffer coating reduces particle collision energy, improving the uniformity and integrity of bulk grain receiving. In summary, this embodiment not only improves the quality of bulk grain delivery and operational stability, but also possesses high applicability and safety. Attached Figure Description

[0040] Figure 1 This application provides a cross-sectional view of the overall structure and a schematic diagram of the grain discharge path for embodiments of the present application;

[0041] Figure 2 A schematic diagram of the conical fairing and the flow divider is provided for embodiments of this application;

[0042] Figure 3 A schematic diagram of the adjustable nozzle, laser particle size analyzer, and elastic buffer coating provided in the embodiments of this application;

[0043] Figure 4 A flowchart is provided for an embodiment of this application of a method for preventing breakage and grading of bulk grain based on gas-solid coupling and elastic grading.

[0044] In the diagram: 1. Conical flow guide; 2. Flow divider; 3. Adjustable airflow nozzle; 4. Laser particle size analyzer; 5. Controller; 6. Elastic buffer coating; 7. Chamber; 8. Feed inlet; 9. Electromagnetic proportional valve; 10. Miniature electric push rod. Detailed Implementation

[0045] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0046] In the description of this application, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0047] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0048] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0049] like Figures 1-3 As shown, in one embodiment of the bulk grain anti-breakage and anti-grading device and method based on gas-solid coupling and elastic grading in this application, the bulk grain anti-breakage and anti-grading device based on gas-solid coupling and elastic grading includes a static multi-stage diverter, a pneumatic auxiliary unit, and a dynamic adjustment system, wherein...

[0050] A static multi-stage diverter is located directly below the feed inlet 8 on the top of the silo, and is used to initially divert the bulk grain entering the silo body 7;

[0051] The pneumatic auxiliary unit is arranged on the static multi-stage diverter and outputs controlled airflow to form pneumatic disturbance in order to suppress the grading trend of bulk grain.

[0052] The dynamic adjustment system is electrically connected to the static multi-stage diverter and the pneumatic auxiliary unit, respectively, to monitor the state of the bulk grain in real time and dynamically adjust the diversion parameters to continuously suppress the generation of bulk grain grading.

[0053] In the above illustrative embodiment, a static multi-stage diverter initially diverts the falling bulk grain, ensuring uniform dispersion of the material upon entering the silo 7 and preventing breakage caused by concentrated impact at a single point. A controlled inclined airflow, output by a pneumatic auxiliary unit, actively disturbs the falling trajectory of the bulk grain, effectively weakening the centripetal aggregation tendency of fine particles and improving the material distribution within the silo. A dynamic adjustment system adjusts the airflow pressure and diversion parameters in real time based on sensor monitoring data, maintaining the diversion state within the optimal range and further enhancing the grading suppression effect. In summary, the bulk grain anti-breakage and anti-grading device provided in this embodiment not only reduces the risk of bulk grain breakage and grading but also improves the uniformity of material falling and operational stability, making it suitable for various bulk grain storage and conveying scenarios.

[0054] In some embodiments, the static multi-stage diverter includes multiple conical guide hoods 1, wherein the conical guide hoods 1 are fixedly installed along the central axis of the feed inlet 8 to provide initial guidance for the falling bulk grain so as to achieve radial diffusion; each conical guide hood 1 is provided with a diverting plate 2 arranged in a spiral involute to further divide the radially diffused bulk grain flow into multiple independent material flows.

[0055] It should be noted that the conical guide shroud 1 is fixed to the pre-embedded steel plate at the material discharge port on the top of the silo by welding.

[0056] In some embodiments, each diverter plate 2 is connected to a miniature electric push rod 10, which is used to drive the opening and closing of the diverter plate 2.

[0057] In some embodiments, the pneumatic auxiliary unit includes a plurality of adjustable airflow nozzles 3 spaced and embedded in a conical guide shroud 1. The outlet direction of the adjustable airflow nozzles 3 forms a 30° angle with respect to the trajectory of the falling grain, and they are connected to the air source system through a pipeline equipped with an electromagnetic proportional valve 9. The air source system provides adjustable airflow, forming an upwardly inclined air cushion resistance layer, which increases the circumferential diffusion distance of fine particles and breaks the tendency of impurities to aggregate centripetally.

[0058] In some embodiments, the dynamic adjustment system includes a laser particle size analyzer 4 and a controller 5. The laser particle size analyzer 4 is located on the inner wall of the silo 7 and is used to monitor the particle size distribution and position information of the falling bulk grain in real time. The controller 5 is connected to the laser particle size analyzer 4 and controls the electromagnetic proportional valve 9 and the micro electric push rod 10 respectively according to the monitoring data.

[0059] Specifically, a PID control algorithm is used to calculate the deviation between the monitored value and the set value, and a 4-20mA control current is output to the electromagnetic proportional valve 9 to adjust its opening (0-100%). A PWM signal is output to the miniature electric push rod 10 to control its stroke position, thereby realizing closed-loop automatic adjustment.

[0060] In some embodiments, the diverter plate 2 uses 316L stainless steel as the substrate, and a polyurethane-silicon carbide composite coating is applied to the surface of the substrate as an elastic buffer coating 6 to reduce the impact velocity of the bulk grain and absorb some of the impact kinetic energy. In addition, the surface of the conical guide shroud 1 is also coated with a polyurethane-silicon carbide composite coating as an elastic buffer coating 6.

[0061] like Figure 4 As shown, this application also provides a method for preventing breakage and grading of bulk grain based on gas-solid coupling and elastic grading. This method is applied to the aforementioned bulk grain anti-breakage and anti-grading device and includes the following steps:

[0062] Step 1: Obtain the grain type and preset processing flow rate of the bulk grain to be processed, retrieve the corresponding grading inhibition coefficient from the preset grain type parameter library, and set the initial airflow pressure and the initial opening and closing angle of the diverter 2 accordingly.

[0063] Specifically, the initial airflow pressure is calculated as follows:

[0064] First, calculate the flow rate and density correction coefficients. :

[0065]

[0066] in, Preset processing flow rate; For reference flow rate, the value is taken as 50 t / h; The true density of bulk grain retrieved from the grain type parameter database; For reference density, a value of 1200 kg / m³ is used. 3 .

[0067] Secondly, calculate the target critical airflow velocity. :

[0068]

[0069] in, The hierarchical inhibition coefficient; The maximum critical airflow velocity for this grain variety is retrieved from the grain variety parameter database.

[0070] Finally, calculate the required initial airflow pressure. :

[0071]

[0072] in, For air density, take the value as 1.2 kg / m³. 3 .

[0073] The initial airflow pressure The relationship between the opening percentage of the electromagnetic proportional valve 9 and the airflow pressure is achieved by adjusting the opening degree of the electromagnetic proportional valve 9. The calibration method is as follows: during the commissioning phase, the electromagnetic proportional valve 9 is adjusted to different opening degrees (0%, 25%, 50%, 75%, 100%), and the corresponding outlet airflow pressure is measured. An opening degree-pressure mapping table is then established and stored in the controller 5.

[0074] Specifically, the preset grain parameter database is managed using an SQL structured database to store the physical property parameters of different grains and their optimal parameter combinations under different processing flow rates. These physical property parameters include average particle size, true density, bulk density, angle of repose, and breakage sensitivity coefficient.

[0075] Specifically, the method for determining the graded inhibition coefficient is as follows:

[0076] Based on the settling velocity of different grain particles of different sizes under free fall, the difference in settling velocity between particles of different sizes is calculated.

[0077] Based on the force balance relationship of particles of different sizes under airflow, a force balance equation including gravity, drag and buoyancy terms is established. With the difference in settling velocity and particle physical property parameters as input, the critical airflow velocity corresponding to each particle size is obtained by solving.

[0078] Based on the grain's breakage sensitivity coefficient, the critical airflow velocity is modified to achieve a balance between the graded suppression effect and breakage control.

[0079] Based on the preset grading control targets, the differences in particle settling velocity, the corrected critical airflow velocity, and the crushing sensitivity coefficient are weighted and calculated to finally determine the grading inhibition coefficient for the corresponding grain type.

[0080] Specifically, the force balance equation is expressed as:

[0081]

[0082] in, It is the acceleration due to gravity; For the first batch of bulk grain Volume of particles of different sizes; The drag coefficient of bulk grain particles under airflow; For the first batch of bulk grain The settling velocity of particles of different sizes in air without external airflow; This represents the uncorrected critical airflow velocity. It represents the projected area of ​​the bulk grain particles perpendicular to the airflow direction.

[0083] Specifically, for near-spherical bulk grains, the windward area... The calculation formula is: ,in, For the first batch of bulk grain The particle size of particles of different sizes;

[0084] For non-spherical particles (such as loose grains with husks like rice), a particle shape factor is introduced for correction, and the calculation formula is as follows:

[0085]

[0086] in, The particle shape coefficient is 1.1-1.3 for ellipsoidal particles and 1.3-1.6 for flat particles. The particle shape is determined by physical measurement.

[0087] Specifically, the calculation method for the difference in settling velocity of particles of different sizes is as follows:

[0088] The settling velocity of bulk grain particles of various sizes in air under conditions of no external airflow is calculated using the following formulas: ,in, The aerodynamic viscosity is taken as 1.8 × 10⁻⁶. -5 Pa·s;

[0089] The sedimentation differences between particles are assessed by calculating the difference in sedimentation velocity between adjacent or any two particle sizes.

[0090] Specifically, the formula for calculating the graded inhibition coefficient is as follows:

[0091]

[0092] in, The hierarchical inhibition coefficient; Due to differences in particle settling velocity; This represents the normalized maximum value of the difference in particle settling velocity; This is the corrected critical airflow velocity; This is the normalized maximum value of the corrected critical airflow velocity; The weighting of the difference in particle settling velocity; The weight is the critical airflow velocity. The weight of the breakage sensitivity coefficient, , , Determined based on the characteristics of the grain variety, meeting the requirements + + =1; The crushing sensitivity coefficient, with a value range of 0–1, represents the degree of sensitivity to crushing of bulk grain.

[0093] Specifically, the weighting coefficients α, β, and γ are determined as follows:

[0094] 1) For grains that are easy to grade and not easily broken (such as corn and soybeans, the breakage sensitivity coefficient S < 0.5):

[0095] Since the main problem with this type of grain is the large difference in settling velocity between particles, which easily leads to grading, the weight of particle settling velocity differences should be increased, and the airflow velocity should be appropriately increased to enhance the disturbance. The weighting coefficients are: α=0.5, β=0.35, γ=0.15.

[0096] (2) For grains that are difficult to grade and easily broken (such as wheat and rice, the breakage sensitivity coefficient S > 0.6):

[0097] Because this type of grain has a high risk of breakage, the airflow velocity should not be too high. Therefore, the weight of the critical airflow velocity should be reduced, while the weight of the breakage sensitivity coefficient should be increased. The weighting coefficients are: α = 0.25, β = 0.25, γ = 0.5.

[0098] (3) For grains with moderate characteristics (breakage sensitivity coefficient 0.5 ≤ S ≤ 0.6):

[0099] A balanced weighting is used. The weighting coefficients are: α = 0.4, β = 0.35, γ = 0.25.

[0100] The aforementioned weighting coefficients were determined by performing multiple regression analysis on experimental data from over 100 different grain types and working conditions, combined with grey relational analysis, so that the calculated grading inhibition coefficient K can optimally reflect the actual grading control requirements.

[0101] Specifically, the calculation method for the initial opening and closing angle of the diverter 2 is as follows:

[0102] (1) Determine the effective coverage area requirement of the preset coverage area. :

[0103]

[0104] Where R is the radius of the chamber 7; the coefficient 0.222 is derived from the area π×[(0.85R) of the preset coverage area (annular area with a radius of 0.65R to 0.85R). 2 -(0.65R) 2 ]=0.296πR 2 Multiplying this by the minimum compliance rate of 75% gives 0.222.

[0105] (2) Calculate the coverage area distribution of a single splitter 2: ,in, This represents the total number of splitter plates 2.

[0106] (3) Based on the relationship between the geometric dimensions of the diverter 2 and its coverage area, a formula for calculating the opening and closing angle is established, specifically including: assuming the effective length of the diverter 2 is... The opening and closing angle of the diverter 2 The material flow coverage area formed under the angle relative to the vertical direction can be approximated as the projected area of ​​a fan shape within the preset coverage area. Considering that the diverter plates 2 are arranged in a spiral involute, the coverage area of ​​a single diverter plate 2 is related to its opening and closing angle. The mapping relationship between them is as follows: The coefficient 0.1 is an empirical correction coefficient, which comprehensively considers the actual projected area loss caused by the spiral involute arrangement, the diffusion of material flow in space, and the edge effect of the diverter plate 2. The theoretical opening and closing angle of the diverter plate 2 is obtained by inverse solving. This can be expressed as a formula: .

[0107] (4) Considering the enhancing effect of airflow on the coverage area, the theoretical opening and closing angle is corrected: Since the inclined airflow output by the adjustable airflow nozzle 3 will generate a lateral thrust on the bulk grain, enhancing the radial diffusion ability of the material flow, the actual coverage area of ​​the diverter plate 2 is greater than its geometric projection area. The larger the grading inhibition coefficient K, the higher the required airflow pressure, and the more significant the diffusion enhancement effect. Experiments have verified that the enhancement effect of airflow diffusion on the coverage area is linearly related to the grading inhibition coefficient K, and the correction coefficient is taken as (1-0.3K). Therefore, the initial opening and closing angle of the diverter plate 2 is... The calculation formula is:

[0108]

[0109] Wherein, the coefficient 0.3 represents the graded inhibition coefficient. For every 0.1 increase, the diffusion effect caused by the enhanced airflow can increase the actual coverage of the diverter plate 2 by about 3%, allowing the opening and closing angle of the diverter plate 2 to be appropriately narrowed, thus avoiding excessive dispersion of the material flow.

[0110] The initial opening and closing angle is achieved by driving the diverter plate 2 through the miniature electric actuator 10. The relationship between the stroke position of the miniature electric actuator 10 and the opening and closing angle of the diverter plate 2 is obtained through mechanical calibration. The controller 5 calculates the angle based on the angle. The corresponding PWM signal is output to control the push rod stroke.

[0111] Step 2: Adjust the diverter plate 2 to the initial opening angle, and spray the inclined airflow with the initial airflow pressure through the adjustable airflow nozzle 3 to pre-form an air cushion resistance layer, so as to drive the fine particles to diffuse in the circumferential direction when the loose grain falls, and inhibit the centripetal aggregation of impurities.

[0112] Step 3: Control the bulk grain to fall from the top feed inlet 8 of the silo, and the conical guide hood 1 radially diffuses the falling bulk grain so that the bulk grain flow is distributed in an umbrella shape.

[0113] Step 4: The diversion plate 2 evenly divides the diffused bulk grain flow into multiple streams, completing the automatic circumferential diversion of the bulk grain, so that the streams cover the preset coverage area of ​​the silo cross-section.

[0114] Specifically, the preset coverage area is defined as: an annular area formed with the central axis of the silo 7 as the center and a radius of 0.65 to 0.85 times the radius of the silo 7.

[0115] Specifically, the method for determining the material flow coverage of the preset coverage area is as follows:

[0116] Within the preset coverage area, 8 to 16 virtual monitoring points are set at equal angular intervals. The controller 5 maps the material flow to each virtual monitoring point based on the data fed back by the laser particle size analyzer 4, and calculates the receiving intensity by combining the number of loose grain particles passing through each monitoring point per unit time and their particle size data.

[0117] The material receiving intensity of each virtual monitoring point is compared with the preset material receiving intensity threshold. When the number of virtual monitoring points that reach the preset threshold accounts for no less than 75% of all monitoring points, the coverage condition is deemed to be met.

[0118] The difference in material receiving intensity between virtual monitoring points that have reached the preset material receiving threshold is calculated. When the difference does not exceed 30%, the material receiving distribution in the area is determined to be uniform.

[0119] When both the coverage rate condition and the material receiving uniformity condition are met, it is determined that the material flow has covered the preset coverage area; otherwise, it is determined that it does not meet the standard.

[0120] Specifically, the calculation method for material strength is as follows:

[0121] In time interval Inside, statistical monitoring points First Number of particles passing through ,in: Indicates the monitoring point number; Indicates particle size level;

[0122] The monitoring points are calculated using the following formula. The strength of the material at the point : ,in, This refers to the bulk grain particle shape coefficient. The total number of bulk grain particle size classes;

[0123] The total material intensity is obtained by summing the material intensity at all monitoring points.

[0124] Step 5: During the falling of the bulk grain, the laser particle size analyzer 4 collects particle size distribution data and location information in real time. When it detects that the centripetal aggregation of fine particles exceeds the allowable range, it triggers a grading warning and calculates the current grading deviation value in combination with the grading inhibition coefficient.

[0125] Specifically, the calculation method for the grading deviation value is as follows:

[0126] The collected particle size distribution data were divided into fine, medium, and coarse particles according to particle size. Fine particles have a particle size less than 70% of the standard particle size, medium particles have a particle size between 70% and 130% of the standard particle size, and coarse particles have a particle size greater than 130% of the standard particle size.

[0127] The cross-section of the silo is divided into an inner ring region, a middle ring region, and an outer ring region. The radius of the inner ring region is 0 to 0.35 times the radius of the silo 7, the radius of the middle ring region is 0.35 to 0.70 times the radius of the silo 7, and the radius of the outer ring region is 0.70 to 1.0 times the radius of the silo 7.

[0128] Based on particle size distribution data, calculate the mass percentage of fine, medium and coarse particles in the entire material flow, and use it as the ideal mass percentage of each layer.

[0129] Calculate the deviation between the actual mass percentage and the ideal mass percentage for each particle size within each sphere, and use the weighted sum of squares of all deviations as the final classification deviation value.

[0130] Specifically, the grading thresholds are set according to different grain types: for conventional bulk grain crops such as corn and wheat, the grading threshold is set at a grading deviation of no more than 12% to 18%; for oil crops such as soybeans and rapeseed, the grading deviation is set at a grading deviation of no more than 15% to 22%; and for bulk grains with husks such as rice, the grading deviation is set at a grading deviation of no more than 10% to 15%.

[0131] Step 6: If the grading deviation value does not exceed the preset grading threshold, maintain the current operating parameters and continue to perform the bulk grain diversion operation.

[0132] Step 7: If the grading deviation value exceeds the preset grading threshold, adjust the airflow pressure of the airflow nozzle and the opening and closing angle of the flow divider 2 according to the degree of deviation, and verify the adjustment effect in real time until the grading deviation value drops below the grading threshold.

[0133] In some embodiments, the real-time verification method for the adjustment effect is as follows:

[0134] During the adjustment of the target parameters, the grading deviation value is calculated every 200 to 500 milliseconds, and the material flow coverage information is recorded at the same time; the trend of the continuously calculated grading deviation value reflects the real-time impact of parameter adjustment on the bulk grain diversion effect.

[0135] After the parameters are adjusted and the system has been running stably for 20 to 40 seconds, a comprehensive data collection and analysis is performed to calculate the grading deviation value and compare it with the preset grading threshold.

[0136] If the graded deviation values ​​for three consecutive sampling periods are all below the threshold and show a stable or decreasing trend, the adjustment effect is deemed satisfactory, and the current parameters are locked to continue operation; if the graded deviation value rebounds after an initial decrease, the adjustment direction is deemed correct but the adjustment magnitude is insufficient, and the adjustment amount is further increased based on the current parameters; if the graded deviation value increases instead of decreasing, the adjustment direction is deemed incorrect, and the parameters are reverted to the previous set and adjusted in the opposite direction.

[0137] Step 8: After completing the bulk grain diversion operation for the current batch, store the operating parameters and particle size distribution data in the grain parameter database.

[0138] In the above illustrative embodiment, the bulk grain anti-breakage and anti-grading method based on air-solid coupling and elastic grading achieves uniform distribution of bulk grain in the initial stage of descent by setting the initial airflow pressure and the opening angle of the diverter plate 2, thus suppressing particle concentration and breakage. An air cushion resistance layer is formed by the inclined airflow, guiding fine particles to diffuse circumferentially, preventing impurities from agglomerating and improving the uniformity of material flow coverage. A laser particle size analyzer 4 collects particle size and aggregation data in real time, and the dynamic adjustment system automatically adjusts the airflow pressure and the opening angle of the diverter plate 2 according to the deviation value, continuously optimizing the diversion state and maintaining the grading suppression effect. After batch operation is completed, the operating parameters and particle size data are stored in the grain parameter database, enabling continuous optimization of the control strategy. Therefore, the bulk grain anti-breakage and anti-grading method provided in this embodiment not only effectively reduces the risk of bulk grain breakage and grading, improves the uniformity and integrity of material falling, but also improves the system's operational stability and applicability, while reducing manual intervention, simplifying the operation process, and saving operating costs.

[0139] Through the description of several embodiments of the bulk grain anti-breakage and anti-grading device and method based on gas-solid coupling and elastic grading of this application, it can be seen that the embodiments of the bulk grain anti-breakage and anti-grading device and method based on gas-solid coupling and elastic grading of this application have at least one or more of the following advantages:

[0140] 1. This application achieves uniform distribution of bulk grain during the falling process by eliminating dynamic mechanical components and adopting a combination of static multi-stage diversion and pneumatic-assisted control, thereby reducing mechanical wear, minimizing the risk of breakage, and simplifying the equipment structure and maintenance process;

[0141] 2. This application utilizes the structure of the bin body 7 itself as a graded buffer medium to effectively absorb the impact energy of falling bulk grain, slow down the material flow speed, make the particles more stable during the falling process, and improve the integrity of bulk grain and the uniformity of receiving materials.

[0142] 3. This application introduces real-time feedback regulation, which dynamically monitors the particle size distribution and aggregation of bulk grain through particle size sensors, and adjusts the diversion ratio and pneumatic parameters in real time to continuously optimize the bulk grain diversion state, effectively suppress the grading trend, and improve the control accuracy and system stability of the feeding process.

[0143] 4. This application uses a biomimetic elastic composite material on the surface of the diversion plate 2 to reduce particle collision energy and buffer impact force, thereby further improving the uniformity and integrity of bulk grain receiving and enhancing the safety and applicability of the system operation.

[0144] 5. This application establishes a complete calculation system from grain type parameters to control parameters. By using the graded inhibition coefficient as an intermediate bridge, multi-dimensional parameters such as grain physical characteristics, processing flow rate, and silo structure 7 are mapped to initial airflow pressure and the opening angle of the diverter plate 2. This achieves the quantification, standardization, and repeatability of parameter settings, enabling those skilled in the art to directly calculate and implement them according to actual working conditions, thereby improving the operability and engineering application value of the technical solution.

[0145] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

Claims

1. A method for preventing breakage and grading of bulk grain based on gas-solid coupling and elastic grading, applied to a device for preventing breakage and grading of bulk grain based on gas-solid coupling and elastic grading, characterized in that, The bulk grain anti-breakage and anti-grading device includes a static multi-stage diverter, a pneumatic auxiliary unit, and a dynamic adjustment system. A static multi-stage diverter is located directly below the feed inlet on the top of the silo and is used to initially divert the bulk grain entering the silo. The static multi-stage diverter includes multiple conical guide hoods, which are fixedly installed along the central axis of the feed inlet to initially guide the falling bulk grain and cause it to diffuse radially. Each conical guide hood is equipped with a diverting plate to further divide the radially diffused bulk grain flow into multiple independent flow streams. Each diverting plate is connected to a miniature electric push rod, which is used to drive the opening and closing of the diverting plate. The pneumatic auxiliary unit is arranged on the static multi-stage distributor and outputs controlled airflow to form pneumatic disturbance to suppress the grading trend of bulk grain. The pneumatic auxiliary unit includes multiple adjustable airflow nozzles arranged at intervals on the conical guide shroud. The adjustable airflow nozzles are connected to the air source system through pipelines equipped with electromagnetic proportional valves. The dynamic adjustment system is electrically connected to the static multi-stage diverter and the pneumatic auxiliary unit, respectively, for real-time monitoring of the bulk grain status and dynamic adjustment of the diversion parameters. The dynamic adjustment system includes a laser particle size analyzer and a controller. The laser particle size analyzer is installed on the inner wall of the bin and is used to monitor the particle size distribution and position information of the falling bulk grain in real time. The controller is connected to the laser particle size analyzer, the electromagnetic proportional valve, and the micro electric push rod. The controller is configured to: adjust the opening of the electromagnetic proportional valve according to the particle size distribution and position information of the bulk grain to adjust the jet pressure of the adjustable airflow nozzle, and adjust the extension and retraction length of the micro electric push rod to adjust the opening and closing of the diverter plate. The method for preventing breakage and grading of bulk grain includes the following steps: The type of bulk grain to be processed and the preset processing flow rate are obtained. The corresponding grading and inhibition coefficients are retrieved from the preset grain parameter library, and the initial airflow pressure and the initial opening and closing angle of the diverter are set accordingly. Adjust the diverter to the initial opening angle and spray the inclined airflow at the initial airflow pressure through the adjustable airflow nozzle to pre-form an air cushion resistance layer, so as to drive fine particles to diffuse in the circumferential direction when the loose grain falls and inhibit the centripetal aggregation of impurities. The bulk grain is controlled to fall from the top feed inlet of the silo, and the conical guide hood diffuses the falling bulk grain radially, so that the bulk grain flow is distributed in an umbrella shape; The diversion plate evenly divides the diffused bulk grain flow into multiple streams, completing the automatic circumferential diversion of the bulk grain and ensuring that the streams cover the preset coverage area of ​​the silo cross-section. During the falling of the bulk grain, the laser particle size analyzer collects particle size distribution data and location information in real time. When it detects that the centripetal aggregation of fine particles exceeds the allowable range, it triggers a grading warning and calculates the current grading deviation value in combination with the grading inhibition coefficient. Determine whether the deviation value exceeds the preset grading threshold: if it does not exceed the threshold, maintain the current operating parameters and continue to perform the bulk grain diversion operation; if it exceeds the threshold, adjust the airflow pressure of the airflow nozzle and the opening and closing angle of the diverter according to the degree of deviation, and verify the adjustment effect in real time until the grading deviation value drops below the grading threshold. The formula for calculating the graded inhibition coefficient is: in, The hierarchical inhibition coefficient; Due to differences in particle settling velocity; This represents the normalized maximum value of the difference in particle settling velocity; This is the corrected critical airflow velocity; This is the normalized maximum value of the corrected critical airflow velocity; As the weight of the difference in particle settling velocity, The weight is the critical airflow velocity. The weight of the breakage sensitivity coefficient, , , Determined based on the characteristics of the grain variety, meeting the requirements + + =1; The crushing sensitivity coefficient, with a value range of 0–1, represents the degree of sensitivity to crushing of bulk grain.

2. The method for preventing breakage and grading of bulk grain according to claim 1, characterized in that, The conical fairing is arranged in an axisymmetric inverted conical structure; multiple flow dividers are arranged in a spiral involute pattern.

3. The method for preventing breakage and grading of bulk grain according to claim 1, characterized in that, The surfaces of the conical deflector and the diverter are coated with an elastic buffer coating to reduce the impact speed of the bulk grain and absorb some of the impact kinetic energy.

4. The method for preventing breakage and grading of bulk grain according to claim 1, characterized in that, The outlet direction of the adjustable airflow nozzle is set at an angle relative to the trajectory of the falling grain.

5. The method for preventing breakage and grading of bulk grain according to claim 1, characterized in that, The method for determining the material flow coverage of the preset coverage area is as follows: Multiple virtual monitoring points are set at equal angular intervals within the preset coverage area. The controller maps the material flow to each virtual monitoring point based on the data fed back by the laser particle size analyzer, and calculates the receiving intensity by combining the number of loose grain particles passing through each monitoring point per unit time and their particle size data. The material receiving intensity of each virtual monitoring point is compared with the preset material receiving intensity threshold. When the proportion of virtual monitoring points that reach the preset threshold to all monitoring points is not less than the set proportion, the coverage condition is determined to be met. The difference in material receiving intensity between virtual monitoring points that have reached the preset material receiving threshold is calculated. When the difference does not exceed the preset difference, the material receiving uniformity condition is determined to be met. When both the coverage rate condition and the material receiving uniformity condition are met, it is determined that the material flow has covered the preset coverage area; otherwise, it is determined that it does not meet the standard.

6. The method for preventing breakage and grading of bulk grain according to claim 5, characterized in that, The method for calculating the strength of the material is as follows: In time interval Inside, statistical monitoring points First Number of particles of different sizes passing through ,in: Indicates particle size level; Indicates the monitoring point number; The monitoring points are calculated using the following formula. The strength of the material at the point : ,in, This refers to the bulk grain particle shape coefficient. The true density of bulk grain retrieved from the grain type parameter database; For the first batch of bulk grain The particle size of particles of different sizes; The total number of bulk grain particle size classes; The total material intensity is obtained by summing the material intensity at all monitoring points.

7. The method for preventing breakage and grading of bulk grain according to claim 1, characterized in that, The method for calculating the grading deviation value is as follows: The collected particle size distribution data were divided into fine, medium, and coarse particle sizes according to particle size. The cross-section of the silo is divided into an inner ring area, a middle ring area, and an outer ring area. Based on particle size distribution data, calculate the mass percentages of fine, medium, and coarse particles in the entire silo flow and use them as the ideal mass percentages for each zone. Calculate the deviation between the actual mass percentage and the ideal mass percentage for each particle size within each region, and use the weighted sum of squares of all deviations as the final classification deviation value.

8. The method for preventing breakage and grading of bulk grain according to claim 1, characterized in that, The method for preventing breakage and grading of bulk grain also includes: After completing the bulk grain diversion operation for the current batch, the operating parameters and particle size distribution data are stored in the grain parameter database.

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