EDEM-based multi-package type packaging model design method

Abstract

The invention relates to the technical field of food packaging, in particular to a method for designing a plurality of packaging models based on an EDEM (Extended Digital Elevation Model). Comprising a centrifugal feeding mechanism, a conveying belt and a discharging port, a conical rotating disc is arranged in the middle of the centrifugal feeding mechanism, a discharging rotating disc surrounds the bottom face of the conical rotating disc, a brush is arranged above the discharging port, a baffle is arranged on the discharging rotating disc, and a plurality of grooves are formed in the discharging rotating disc. And establishing a brush position model, a conical turntable taper model, a conical turntable rotating speed model and a baffle size model. The position of the brush, the rotating speed and the taper of the conical turntable, the feed opening and the corresponding baffle plate are optimized, so that the comprehensive performance of a plurality of packaging lines is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of food packaging, and in particular to a method for designing a multi-piece packaging model based on EDEM. Background Art

[0002] Packaging machinery is growing rapidly and occupies a very important part in the machinery industry. It is often the last line of the production line. Automated packaging can automatically provide bags and packaging materials, and complete the processes of material adsorption, transportation, clamping, weighing, and sealing. Traditional packaging machines are mainly based on fixed volume or weighing. Fixed volume is often liquid or small particles, such as rice grains, mung beans, etc., and weighing is to divide the material pile and then obtain a certain weight of packaging through mathematical processing. As people's health awareness improves, the demand for nuts increases, and products such as daily nuts have emerged. People pay more and more attention to the daily nutrient absorption, and the packaging form with a fixed number of pieces can meet people's control over daily nutrient intake.

[0003] Defects and shortcomings of the existing technology:

[0004] 1. When there are too many nuts, multiple nuts may be dropped during the sorting process due to insufficient rotation speed of the feeding turntable, unreasonable density of the circular feeding ports, and unreasonable positions of the brush and baffle.

[0005] 2. Untimely feeding, mainly due to blockage caused by nut accumulation or nuts not being able to enter the empty bin of the feeding turntable due to high rotation speed, resulting in the omission of nut feeding. Figure 1 shown. Summary of the invention

[0006] The problem to be solved by the present invention is to avoid the traditional manual counting form and establish a more suitable counting and sorting line based on the vacuum nut packaging machine.

[0007] In view of the shortcomings of the prior art, the technical solution adopted by the present invention to solve the technical problems is: a method for designing a multi-piece packaging model based on EDEM, including a centrifugal feeding mechanism, a conveyor belt, and a discharge port. A conical turntable is arranged in the middle of the centrifugal feeding mechanism, and a discharge turntable is surrounded by the bottom surface of the conical turntable. A brush is arranged above the discharge port, and a baffle is arranged on the discharge turntable. The discharge turntable is provided with a plurality of grooves. The method is based on EDEM discrete element simulation software to establish a brush position model, a conical turntable taper model, a conical turntable rotation speed model and a baffle angle model.

[0008] Preferably, several material sorting line optimization metrics and simulation software settings are set in EDEM, and several material sorting line optimization metrics include the re-falling time interval t1, the missing time interval t interal And the rapidity k, the re-falling time interval t1, t1 satisfies the inequality:

[0009]

[0010] Where: n is the number of grooves of the unloading turntable; ω is the angular velocity of the unloading turntable, in rad / s;

[0011] When the front and rear particles leak, the time interval between them is t interal , the leakage time interval satisfies the inequality:

[0012] Fast n1 is the number of groups correctly counted per unit time t, and t is the time taken to correctly count n1 groups of groups.

[0013] Preferably, the simulation software settings include nut particle property settings, equipment property settings, conveyor belt property settings, particle factory settings and solid phase physical model selection; the nut particle property settings are to create a new material "particle" in EDEM and set the nut physical parameters; the steel density is set to 7930kg / m in the equipment property settings 3 , Poisson's ratio is 0.3, shear modulus is 7.423×1010Pa; according to the table, the equipment intersections are set, that is, the mechanical relationship between nuts and equipment, including the collision recovery coefficient, static friction coefficient and rolling friction coefficient between particles and steel plates. The conveyor belt property settings include the use of green rubber material for the conveyor belt of several material sorting lines, and the steel density is set to 1kg / m 3 , Poisson's ratio is 0.47, shear modulus is 2.667×106Pa, according to the intersections of the equipment set in the table, that is, the mechanical relationship between nuts and equipment, including the collision recovery coefficient, static friction coefficient and rolling friction coefficient between particles and belts; the setting of the particle factory needs to be set in the geometric model to avoid the simulation speed being slowed down. Inside the centrifugal material mechanism in EDEM, a particle generation factory is set on the upper part of the conical turntable, and the size of the particle factory generation surface is set to: 300mm×300mm; In the selection of solid phase physical model, the Hertz-Mindlin (no-slip) model is selected as the contact model between particles in the EDEM simulation setting, and the standard rolling friction model (Standard Rolling Friction) is used to calculate the collision of particles in the simulation.

[0014] Preferably, the conical turntable taper model is based on the shallow bin model, and the nut particles between the conical turntable and the outer wall conform to the shallow bin model:

[0015] F N2 -F l -F r =0

[0016]

[0017] Among them: F N2 F is the support force of the outer ring of the conical turntable on the nut particles; l is the pressure of the upper nut particles on the lower nuts along the y direction; Fr is the centrifugal force of the nut particles; F v is the vertical pressure of the upper nut particles on the lower nut particles along the direction of gravity, K is F l With F V The ratio of is the internal friction angle; γ is the gravity, the unit is kN / m 3 ;z h is the depth of the nut; m is the mass of a single nut; R is the radius of the cone base. Combining the centrifugal force and the above formula, we get:

[0018]

[0019] Preferably, the angles between the cone turntable generatrix and the ground in the cone turntable taper model are set to 20°, 25°, 35°, and 40°, respectively; when modeling the cone turntable speed model, the speeds are set to 0.25rad / s, 0.3rad / s, 0.35rad / s, 0.4rad / s, 0.45rad / s, and 0.5rad / s, respectively; when modeling the baffle angle model, the angles selected are initial, 25°, 20°, and 15°.

[0020] The beneficial effects of the present invention are as follows: 1. The structural form of the material sorting and packaging machine is determined in combination with the actual needs of packaging a large number of pieces, and has a good effect.

[0021] 2. The optimization of brush position, cone turntable speed and taper, feed port and corresponding baffle greatly improves the overall performance of several packaging lines.

[0022] 3. The model design method is divided into four modeling types: brush position model, conical turntable taper model, conical turntable speed model and baffle size model. Each model is simulated to obtain comparative data, and then the optimal choice for each structure is obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram involved in the background technology of the present invention.

[0024] Figure 2 It is a schematic diagram of the position of the brush involved in the present invention.

[0025] Figure 3 It is a histogram of material arrangement at different positions of the brush in the present invention.

[0026] Figure 4 It is a schematic diagram of nut force modeling involved in the present invention.

[0027] Figure 5 It is a schematic diagram of the taper of the conical turntable involved in the present invention.

[0028] Figure 6 It is a column chart of material sorting of a conical turntable with different tapers involved in the present invention.

[0029] Figure 7 It is a schematic diagram of the relative movement between the conical turntable and the unloading turntable in the present invention.

[0030] Figure 8 It is a bar graph of different rotation speeds of the conical turntable involved in the present invention.

[0031] Fig. 9 It is a schematic diagram of a feed opening and a baffle involved in the present invention.

[0032] Fig.10 It is a bar graph of baffles of different sizes involved in the present invention.

[0033] Fig.11 It is a schematic diagram of the centrifugal material mechanism and the conveyor belt in the present invention.

[0034] Fig.12 It is a schematic diagram of the centrifugal material mechanism and the conveyor belt from another angle in the present invention.

[0035] Explanation of the reference numerals: 1. centrifugal feeding mechanism; 11. feeding port; 12. brush; 13. conical turntable; 14. feeding turntable; 141. groove; 15. outer wall; 16. baffle; 2. conveyor belt; 3. discharge port. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0037] As shown in the figure, in the dried fruit food packaging process, a material sorting mechanism is used to pack nuts according to a certain weight or number of pieces. The present invention is applicable to the case of packaging according to the number of pieces, and involves a centrifugal material sorting mechanism 1, which is provided with a feeding port 11, and a conveyor belt 2 is arranged below the feeding port 11, and the conveyor belt 2 conveys the nuts to the discharge port 3. The centrifugal material sorting mechanism 1 also includes a brush 12, a conical turntable 13, a feeding turntable 14 and an outer wall 15. The feeding turntable 14 surrounds the bottom surface of the conical turntable 13, and the brush 12 is arranged on the outer wall 15 and is located above the feeding port 11. The feeding port 11 is opened at the bottom of the outer wall 15 and is located below the feeding turntable 14. The feeding turntable 14 is provided with a plurality of grooves 141, and the grooves 141 are used to accommodate single nuts; the baffle 16 is arranged on the feeding turntable 14 and is located above one side of the feeding port 11.

[0038] The key elements of the centrifugal feeding mechanism are the position of the brush 12, the design of the taper and rotation speed of the conical turntable 13, and the design of the size of the feeding port 11 and the corresponding baffle 16. For this design, the optimization design is combined with discrete element modeling to obtain the optimal placement of the brush 12, the taper and rotation speed of the conical turntable 13, and the angle of the feeding port 11 and the baffle 16.

[0039] 1. Brush 12 position model

[0040] In the process of sorting, the brush 12 can play the role of segmenting, blocking and re-planning the movement of nut particles. The position of the brush 12 of the nut particles mainly has three forms, such as Figure 2 As shown, Figure 2 (a) The brush 12 is located in a horizontal square (the length direction of the brush 12 is collinear with the bottom diameter of the conical turntable 13); Figure 2 (b) the brush 12 is located in the vertical direction (the length direction of the brush 12 is in line with the movement direction of the unloading turntable 14); Figure 2 (c) The brush 12 is located in the tangential direction (the length direction of the brush 12 is tangent to the circumference of the bottom surface of the conical turntable 13). Different placements of the brush 12 have obvious differences in the combing effect on the nut particles, so a placement of the brush 12 with better combing effect should be selected as much as possible.

[0041] First of all, the optimization measurement standard of the nut sorting line is established. The material flow of the nut sorting line is transmitted to the unloading point. Accurate counting of nuts and stable and fast feeding are two important design standards of the sorting line. Therefore, mathematical indicators for the optimization measurement of accurate counting are established.

[0042] Accurate number of particles index: Since the feeding turntable 14 rotates at a constant speed, the time difference between the front and back particles remains stable when feeding accurately. When the time difference between the front and back particles is large or small, it means that the feeding port leaks or multiple particles fall from the same feeding port. Therefore, when studying the accuracy of the material sorting line, it is necessary to calculate the time difference between the front and back particles. The front and back particles falling in the same groove 141 are called re-falling, that is, two nuts fall in the same groove 141 in a very short time, and the time interval between the two nuts is the re-falling time interval t1. t1 satisfies the inequality:

[0043]

[0044] Wherein: n is the number of grooves 141 of the unloading turntable 14; ω is the angular velocity of the unloading turntable 14, and the unit is rad / s.

[0045] When the front and rear particles leak, the time interval between them is t interal , the leakage time interval satisfies the inequality:

[0046] Fast counting index: Fast blanking is relatively simple. On the basis of accurate counting, the fastness k, n1 is the number of groups correctly counted per unit time t, and t is the time taken to correctly count n1 groups of groups.

[0047] Stable number of particles index: In actual production, in order to ensure a fixed number of particles, photoelectric sensors are used to automatically count the particles. Establishing a stable number of particles index is conducive to reducing the frequency of adjusting the transmission belt speed of the production line. Stability is judged by the variance of the time interval difference between blanking. When the variance is large, repeated blanking or missing blanking is more frequent, and vice versa, repeated blanking or missing blanking is less frequent.

[0048] Secondly, the simulation software is set up, and the inter-particle contact parameters required for simulation are shown in Table 1;

[0049] Simulation settings: Nut particle property settings: Create a new material "particle" in EDEM and set the physical parameters of the nuts: for example, the density of walnuts is 470kg / m 3 , Poisson's ratio is 0.29, and the shear modulus is 5.08×109Pa; according to the intersections of the materials set in the table, that is, the mechanical relationship between nuts and nut particles, including the collision recovery coefficient between particles, the static friction coefficient, and the rolling friction coefficient between particles.

[0050] Equipment property setting: Several material handling lines are made of stainless steel, and the steel density is set to 7930kg / m 3, Poisson's ratio is 0.3, and the shear modulus is 7.423×1010Pa; according to the intersections of the equipment set in the table, that is, the mechanical relationship between the nut and the equipment, including the collision recovery coefficient, static friction coefficient and rolling friction coefficient between the particles and the steel plate.

[0051] Conveyor belt property settings: Since the conveyed material is food nuts, the conveyor belts of several material handling lines use green rubber material and set the steel density to 1kg / m 3 , Poisson's ratio is 0.47, shear modulus is 2.667×106Pa, according to the table set the intersections of the equipment, that is, the mechanical relationship between nuts and equipment, including the collision recovery coefficient, static friction coefficient and rolling friction coefficient between particles and belts. EDEM can import external models, which makes up for EDEM's ability to build models. Use SolidWorks step format files to correctly import, check the origin coordinates, etc., and set equipment properties for models such as centrifugal feeding mechanism 1, baffle 16, conical turntable 13, unloading turntable 14, and conveyor belt 2.

[0052] In actual production, nut particles are dropped directly in batches. The setting of the particle factory: In order to avoid the motion trajectory of the generated particles appearing outside the simulation area, resulting in a waste of EDEM computing resources, the location of the particle factory needs to be set in the geometric model to avoid the simulation speed being slowed down. Inside the centrifugal feeding mechanism 1 in EDEM, a particle generation factory is set on the upper part of the conical turntable 13. The size of the particle factory generation surface is set to: 300mm×300mm. The nut mass related to time is selected in the setting. The relationship between the generated particles and time is f(t)=2-t(kg), kg is the unit of the quantity represented by this formula, 2 is the total mass of the particle factory, and t represents time; in the simulation, particles of different sizes are mixed according to the actual working conditions. Among the nut particles actually fed, standard size particles account for 90%, 1.1 times the size accounts for 5%, and 0.9 times the size accounts for 5%.

[0053] Selection of solid phase physical model: Considering the surface characteristics of nut particles, the Hertz-Mindlin (no-slip) model was selected as the contact model between particles in the EDEM simulation settings, and the standard rolling friction model (Standard Rolling Friction) was used to calculate the collision of particles in the simulation.

[0054] Set the gravity direction relative to the model to ensure the real falling of particles. The gravity acceleration is set to g = 9.83m / s 2 . Set the total calculation time to 60s and the data writing frequency to 0.01s.

[0055] The optimization metric standards of the material discharge conditions of different structures of the centrifugal material feeding mechanism 1 are compared. This paper mainly simulates and models the material discharge conditions by changing the position of the brush 12, the taper of the conical turntable 13, the rotation speed of the conical turntable 13, the size of the material discharge port 11 and the angle of the baffle 16.

[0056] The particles fall from the same position above the conical turntable 13, and contact the brush 12 after falling from the conical turntable 13. Under the action of the brush 12 rotating and pressing down, the nut particles pass through the grooves 141 of the feeding turntable 14 and the feeding port 11 and fall accurately onto the conveyor belt 2. Since the time of the first feeding is related to the feeding position, the measurement standard does not calculate the time before the first one. The feeding turntable 14 rotates at a counterclockwise speed of 0.4 rad / s, and the conical turntable 13 rotates at a clockwise speed of ω of 0.4 rad / s. n is the number of grooves 141. Here, n is 40 for research. The correct time interval between two adjacent nuts falling is calculated as follows:

[0057]

[0058] So the re-fall time interval here is t1≤0.2s, and the leakage time interval is t interal ≥0.6s. Use EDEM post-processing software to simulate several particles in the silo area at each moment for one minute, and then export the EXCEL table to calculate the time difference between the front and rear blanking. The correct blanking time difference is 0.2s to 0.6s.

[0059] Depend on Figure 3 It can be seen that within 1 minute, when the brush 12 is placed vertically, 38 groups of three nuts are successfully and accurately counted, which is the highest number, and the number of repeated dropping and missing dropping is the least, and the missing dropping is more concentrated, and its accuracy, speed and stability are the highest. The number of repeated dropping is large when placed horizontally and tangentially, which shows that the structure is not blocking enough for nuts, which will easily lead to more nuts in the packaging bag. When placed tangentially, the space at the discharge port is larger. When nuts are piled up, the nuts at the piled place are easy to drop at the same time. Therefore, the brush 12 should be placed vertically.

[0060] 2. Conical turntable 13 taper model

[0061] In the circular wall, material accumulation will be affected by the structure and motion state of the internal objects. In order to further model the influence of other structures on the accumulation of nut materials, a shallow warehouse model of the nut accumulation is established, and qualitative modeling is performed on the influence of the structure and motion state of the conical turntable 13 on the contacting nuts.

[0062] When the nuts fall into the silo, they first contact the side of the tapered conical turntable 13, and then move toward the lower feed port 11 under the action of gravity and the centrifugal force of the conical turntable 13. Figure 4To model the forces on the stacked nuts, the nut particles are subjected to a balanced force in the y-axis direction of the horizontal plane: F N2 -F l -F r =0

[0063] Among them: F N2 The outer ring of the conical turntable 13 supports the nut particles;

[0064] F l is the pressure of the upper nut particles on the lower nut along the y direction;

[0065] Fr is the centrifugal force of nut particles;

[0066] The nut particles between the conical turntable 13 and the outer wall 15 conform to the shallow warehouse model:

[0067]

[0068] Among them: F v is the vertical pressure of the upper nut particles on the lower nut particles along the direction of gravity, K is F l With F V The ratio of is the internal friction angle; γ is the gravity, the unit is kN / m 3 ;z h is the depth of the nut; m is the mass of a single nut; R is the radius of the cone base. Combining the centrifugal force and the above formula, we get:

[0069]

[0070] Theoretically, the force exerted on the nut by the outer wall 15 is positively correlated with the position and the radius R of the rotation center. Reducing the force on the nut in the y-axis direction can optimize the stacking of the nut material.

[0071] EDEM is used to simulate the angle between the generatrix and the bottom surface of the conical turntable 13. The angle of the conical turntable 13 is as follows: Figure 5 As shown in Figure 1, the angles of the conical turntable 13 are set to 20°, 25°, 35°, and 40° in SolidWorks for simulation. The simulation results of the conical turntable 13 at different angles are shown in Figure 1. Figure 6 It can be seen that within 1 minute, when the angle of the conical turntable 13 is 20° and 25°, 41 groups of three nuts are successfully and accurately counted, which is the highest, and the number of repeated dropping and missed dropping is the least, and the missed dropping is more concentrated, and its accuracy, speed and stability are the highest. The other angle structures have sufficient blocking properties for nuts, the accumulation effect is enhanced, and the total number of nuts decreases. In actual production, infrared sensors are used for identification. When repeated dropping occurs, it is not conducive to the belt speed regulation. Therefore, in order to avoid repeated dropping, the angle of the conical turntable 13 is selected to be 25°, but there will still be a certain degree of accumulation. The movement speed of the conical turntable 13 is further studied below.

[0072] 3. Conical turntable 13 speed model

[0073] The conical turntable 13 and the unloading turntable 14 rotate at opposite speeds of 0.4 rad / s. From the shallow warehouse effect, it can be seen that when the angular velocity of the conical turntable 13 is large, the centrifugal force of the nuts will increase. In order to meet the needs of production efficiency, the following model is built for the speed of the conical turntable 13. When the angular velocity of the conical turntable 13 and the speed of the unloading turntable 14 are large, the centrifugal force of the nuts will increase. In order to meet the needs of production efficiency, the following model is built only for the speed adjustment of the conical turntable 13.

[0074] Depend on Figure 8 It can be seen that within 1 minute, when the speed of the conical turntable 13 was 0.4rad / s, 41 groups of three were successfully and accurately counted, which was the highest, and the number of repeated dropping and missing dropping was the least, and the missing dropping was more concentrated, and its accuracy, speed and stability were the highest. At 0.5rad / s, due to the high speed, the material accumulated on the outermost wall and missed. Therefore, in actual production, in order to avoid repeated dropping, the conical turntable 13 should not be too fast. It is not conducive to the belt speed regulation, so in order to avoid repeated dropping, the cone turntable 13 speed of 0.4rad / s is selected as the best.

[0075] 4. Bezel 16 angle model

[0076] The size of the discharge port 11 and the corresponding baffle area are also important areas that come into contact with the nuts during the discharge process. The baffle 16 is used to block the nuts and prevent the nuts from piling up and causing multiple nuts to fall from multiple discharge ports 11. If it is too long, a large amount of nuts will easily accumulate and the nuts will not be able to follow the discharge turntable 14 to leave the accumulation area. If it is too small, the nuts will not be able to be discharged immediately.

[0077] First, the improved feed port model and the corresponding baffle model are remodeled in SolidWorks as follows: Fig. 9 As shown, EDEM is used to model the blanking, and the angles selected when modeling the baffle 16 angle model are initial, 25°, 20°, and 15°. Fig.10 It can be seen that when the opening angle of the baffle 16 is set to 25° ( Fig. 9 e part) and the feed opening angle is 20°( Fig. 9 In the middle d part), the initial repeated and missed material dropping is improved, and 44 groups can be divided into one minute, which meets the production requirements with the highest accuracy, speed and stability. When the opening angle of the baffle 16 is 15°, the baffle 16 is small and the material is not blocked enough, resulting in repeated material dropping, and the effect is poor.

[0078] The contact parameters of EDEM simulation are shown in the following table. The overall structure of the centrifugal feeder is as follows: Fig.11, the nuts fall correctly onto the conveyor belt 2 and are then transported to the packaging line outlet 3 via the conveyor belt.

[0079]

[0080] In summary, the position selection of the brush 12 Figure 2 (b) The vertical direction (the length direction of the brush 12 is in line with the movement direction of the discharge turntable 14) is optimal, the taper angle of the conical turntable 13 is 25°, the rotation speed of the conical turntable 13 is 0.4 rad / s, the opening angle of the baffle 16 is 25°, and the discharge port angle is 20°, which can achieve 100% discharge.

Claims

1. A method for designing a multi-piece packaging model based on EDEM, comprising a centrifugal feeding mechanism (1), a conveyor belt (2), and a discharge port (3), wherein a conical turntable (13) is arranged in the middle of the centrifugal feeding mechanism (1), a discharge turntable (14) surrounds the bottom surface of the conical turntable (13), a brush (12) is arranged above the discharge port (11), a baffle (16) is arranged on the discharge turntable (14), and a plurality of grooves (141) are provided on the discharge turntable (14), characterized in that: The method is based on EDEM discrete element simulation software to establish a brush (12) position model, a conical turntable (13) taper model, a conical turntable (13) rotation speed model and a baffle (16) angle model.

2. The method for designing a multi-piece packaging based on EDEM as claimed in claim 1, characterized in that: In EDEM, several material sorting line optimization metrics and simulation software settings are set. Several material sorting line optimization metrics include the re-falling time interval t1 and the missing time interval t interal And the rapidity k, the re-falling time interval t1, t1 satisfies the inequality: Wherein: n is the number of grooves (141) of the unloading turntable (14); ω is the angular velocity of the unloading turntable (14), in rad / s; When the front and rear particles leak, the time interval between them is t interal , the leakage time interval satisfies the inequality: Fast n1 is the number of groups correctly counted per unit time t, and t is the time taken to correctly count n1 groups of groups.

3. The method for designing a multi-piece packaging based on EDEM as claimed in claim 2, characterized in that: The simulation software settings include nut particle property settings, equipment property settings, conveyor belt property settings, particle factory settings and solid phase physical model selection; the nut particle property settings are to create a new material "particle" in EDEM and set the nut physical parameters; in the equipment property settings, the steel density is set to 7930kg / m 3 , Poisson's ratio is 0.3, shear modulus is 7.423×1010Pa; according to the table, the equipment intersections are set, that is, the mechanical relationship between nuts and equipment, including the collision recovery coefficient, static friction coefficient and rolling friction coefficient between particles and steel plates. The conveyor belt property settings include the use of green rubber material for the conveyor belt of several material sorting lines, and the steel density is set to 1kg / m 3 , Poisson's ratio is 0.47, shear modulus is 2.667×106Pa, according to the intersections of the equipment set in the table, that is, the mechanical relationship between the nut and the equipment, including the collision recovery coefficient, static friction coefficient and rolling friction coefficient between the particles and the belt; the setting of the particle factory needs to be set in the geometric model to avoid the simulation speed being slowed down. Inside the centrifugal material mechanism (1) in EDEM, a particle generation factory is set on the top of the conical turntable (13), and the size of the particle factory generation surface is set to: 300mm×300mm; In the selection of solid phase physical model, the Hertz-Mindlin (no-slip) model is selected as the contact model between particles in the EDEM simulation setting, and the standard rolling friction model (Standard Rolling Friction) is used to calculate the collision of particles in the simulation.

4. The method for designing a multi-piece packaging based on EDEM as claimed in claim 3, characterized in that: The taper model of the conical turntable (13) is based on the shallow bin model. The nut particles between the conical turntable (13) and the outer wall (15) conform to the shallow bin model: F N2 -F l -F r =0 Among them: F N2 F is the support force of the outer ring of the conical turntable (13) on the nut particles; l is the pressure of the upper nut particles on the lower nuts along the y direction; Fr is the centrifugal force of the nut particles; F v is the vertical pressure of the upper nut particles on the lower nut particles along the direction of gravity, K is F l With F V The ratio of is the internal friction angle; γ is the gravity, the unit is kN / m 3 ; z h is the depth of the nut; m is the mass of a single nut; R is the radius of the cone base. Combining the centrifugal force and the above formula, we get:

5. The method for designing a multi-piece packaging based on EDEM as claimed in claim 3, characterized in that: In the taper model of the conical turntable (13), the angles between the generatrix of the conical turntable (13) and the ground are set to 20°, 25°, 35°, and 40° respectively; when the rotation speed model of the conical turntable 13 is modeled, the rotation speeds are set to 0.25 rad / s, 0.3 rad / s, 0.35 rad / s, 0.4 rad / s, 0.45 rad / s, and 0.5 rad / s respectively; when the angle model of the baffle (16) is modeled, the angles are selected as initial, 25°, 20°, and 15°.

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