# Design and Test of Disturbed Fertilizer Strip-Ejection Device with Vertical Pendulum Bar Based on Discrete Element Method

^{1}

^{2}

^{3}

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Materials and Methods

#### 2.1. Overall DFSD Structure and Working Principle

#### 2.1.1. Overall DFSD Structure

#### 2.1.2. Working Principle

_{10}to the left or right extreme position zone O

_{11}or O

_{12}, and it continuously swings (as shown in Figure 1b). On the one hand, under the action of the PMPB and the ends of APPs I and II in the SRC, the fertilizer is pushed out of the fertilizer discharge port to form a continuous fertilizer flow. On the other hand, the fertilizer is pushed away from the fertilizer-discharge port to form a material-free zone. Under the action of gravity, it is filled with the surrounding fertilizer, causing the fertilizer to self-flow and discharge. The two complement each other, forming a precise fertilizer-discharge process.

#### 2.2. Design and Analysis of Key Components

#### 2.2.1. Analysis of SRC Motion

- Motion Analysis of PMPB

_{1}and A

_{2}) of Motion Point A are connected through the rotation center [20,21], and there are constraints between the four bars of the main swing rod motion mechanism:

_{0}is the length of rocker arm, m; L

_{1}is the length of connecting rod, m; and L is the distance between the crank rotation center and the swing center, m.

_{1}= β + ξ, where β is the angular displacement of the main swing bar (swing angle) (°); β

_{1}is the angle between the main pendulum and the horizontal plane at motion point A (°); and ξ is the angle between the main pendulum and the horizontal at dead center A

_{2}(°).

_{1}A is solved:

_{1}= x

_{A}/L

_{2}, sinα

_{1}= y

_{A}/L

_{2}into Equation (4) and combining Equations (1) to (3), the following Equation (5) is obtained:

_{1},α) of Equation (7) as follows:

_{0}; the distance L between the crank rotation center and the swing center; and the crank rotation angle, α. When the structural parameters of the fertilizer-discharge device (r, r

_{0}, and L) are constant, angular displacement β and angular velocity ω are only related to crank rotation angle α. When the structural parameters of the fertilizer-discharge device (radius of the crank, r; length of the rocker arm, r

_{0}; and distance, L, between the crank rotation center and the swing center) are constant, γ and ξ are constant. Thus, angular velocity ω of the PMPB is only related to crank rotation angle α. As the rotational speed of the crank rocker mechanism increases, angular velocity ω of the PMPB significantly increases. Displacement K and velocity S of the K-point at the end of the PMPB are calculated:

- 2.
- Motion Analysis of APP

_{3}at the end of the main swing rod is satisfied.

_{0}, and angular displacement β of the PMPB. The PMPB and APPs I and II are the same rigid body, and β and ω of the APP are completely the same as the PMPB. The combination motion of the SRC, the displacement, velocity, and acceleration of the PMPB, as well as the ends of APPs I and II, are sine or cosine functions of time (i.e., crank rotation angle α), and the acceleration is always proportional to the displacement. Crank rotation angle α and crank radius r determine the operating frequency f of the SRC.

#### 2.2.2. Mechanical Analysis of SRC

- Mechanical Analysis of PMPB

_{1}. The amount of fertilizer discharged is affected by the following factors: the thrust F of the PMPB, the gravity mg of the fertilizer, the internal friction between the fertilizer particles, and the pressure P of the inclined plane BD. Due to the fact that a line or surface composed of any substance only generates normal pressure on external objects when there is no friction, the friction between the wedge surface and the fertilizer can be ignored when it is smooth. For the sake of analysis, the direction of pressure P is set to be perpendicular to the BD surface, and the force analysis of the PMPB is shown in Figure 3a. When the PMPB is pushed from dead center OB to center OA

_{3}, the force on the fertilizer satisfies the following formula:

_{1}is the normal angle between pressure P and the bottom of the fertilizer box (°), and ${\varphi}_{m}$ is the friction angle between the fertilizer and the bottom of the fertilizer box (°).

_{1}is 130°. The fertilizer moves along the bottom of the fertilizer box without self-locking [19] under pressure P. As shown in Figure 3b, the gravity of the fertilizer will cause fertilizer to self-lock, affecting the fertilizer discharge effect when the PMPB moves from OA

_{3}to dead center OC. As θ increases, the uniformity of fertilizer discharge becomes poor, so wedge angle α

_{1}should be smaller. In fact, to avoid particle fertilizer crushing or other debris blockage, there should be a certain gap between the tip of the guide needle and the fertilizer discharge port (swing rod flow gap). The analysis shows that the optimal wedge angle range is between 35° and 55°, and the specific values are determined later through an EDEM simulation.

- 2.
- Obliquity design of APP

_{1}B and O

_{1}C, which have a phase difference from the PMPB.

_{1}D or O

_{1}E to dead point O

_{1}A

_{3}(i.e., the fertilizer discharge port), resulting in continuous fertilizer discharge. During the stages of O

_{1}D to O

_{1}B or O

_{1}E to O

_{1}C, APPs I and II are disturbed by the PMPB being pushed to discharge fertilizer. The fertilizer pushed by the APP has little effect on fertilizer discharge, except for accelerating the supplement of the fertilizer-free zone formed by the PMPB. During the stages of O

_{1}B to O

_{1}A

_{3}or O

_{1}C to O

_{1}A

_{3}, the PMPB moves toward the dead center position, pushing the fertilizer away from the discharge port, and the fertilizer pushed by the APP is discharged through the discharge port.

#### 2.2.3. Guide Needle and FGPB

#### 2.2.4. The Amount of Fertilizer Discharged

_{1}is the fertilizer discharge per unit area required by agricultural technology, kg/hm

^{2}; B is the working width of the fertilizer applicator, m; v

_{m}is the operating speed of the fertilizer applicator, km/h; and m is the number of fertilizer discharge devices.

_{1}of the PMPB, the tilt angle δ of the APP, the FGPB of the PMPB, and the operation frequency f of the SRC.

#### 2.3. Simulation Test

#### 2.3.1. Simulation Model Establishment

_{k}is the equivalent diameter, m; φ

_{k}is the spherical index, %; and L

_{k}, W

_{k}, and H

_{k}are the three axis dimensions of the fertilizer, m.

_{a}, k, x

_{0,}and b are the coefficients of the normal distribution function. The particles had a fitting degree of R

^{2}= 0.98. Thus, it could be considered that the equivalent diameter of the particles followed the normal distribution law. Therefore, it was determined that the production law of the fertilizer particles in the particle factory followed a normal distribution, as shown in Figure 8.

#### 2.3.2. Analysis of Discrete Element Simulation Process

#### 2.3.3. Experimental Factors and Levels

#### 2.3.4. Calculation of Evaluation Indicators

_{1}and fertilizer discharge accuracy (FDA) Y

_{2}[24] were used to evaluate the uniformity of fertilizer discharge and stability during the process. The grid method was used to obtain data statistics on the uniformity of fertilizer discharge [4,25]. According to the forward speed of the fertilizer discharge device, the collected fertilizer strips were divided into five repeated test zones with a length of 1000 mm along the x-axis. Each zone was subdivided using eight statistical grids with a length and width of 125 mm and 100 mm, and the fertilizer quality within the eight grids was calculated. The statistical grid settings are shown in Figure 12.

_{1}of fertilizer uniformity were obtained in the grid unit [4,18].

_{i}represents the total mass of the fertilizer particles in grid i, g; n indicates the number of statistical grid cells, n = 8; $\overline{m}$ represents the average mass of the fertilizer particles in the statistical grid unit, g; S represents the standard deviation between each statistical grid unit in a single experiment, g; and Y

_{1}represents the CV of fertilizer uniformity between each statistical grid unit in a single experiment, %. The smaller the CV of the fertilizer-discharge uniformity between each statistical grid unit, the better the stability and uniformity of the fertilizer discharge of the fertilizer discharge device. Therefore, the CV of the fertilizer discharge uniformity between each statistical grid unit is used as an evaluation indicator to analyze the operational performance of the fertilizer discharge devices under different structural parameters.

_{2}represents the difference between the theoretical and actual fertilization amounts. The higher the FDA, the smaller the deviation of the fertilizer discharge [26]. The fertilizer-discharge quality within a single fertilizer discharge cycle was measured, and it was compared with the theoretical value. This was repeated three times to calculate the FDA.

#### 2.4. Test Materials and Equipment

## 3. Results

#### 3.1. Results of Regression Model

#### 3.1.1. Scheme and Results of the Experiment

#### 3.1.2. Regression Model and Significance Test 2

_{1}and Y

_{2}with x

_{1}, x

_{2}, x

_{3}, and x

_{4}.

_{1}of fertilizer uniformity and the regression model of FDA Y

_{2}are extremely significant (p < 0.01). Specifically, the CV of fertilizer uniformity F is equal to 34.21, and p is less than 0.001; the FDA of F is equal to 36.12, and p is less than 0.001. The CV of fertilizer uniformity Y

_{1}and the loss of fit term in the regression model of FDA Y

_{2}are not significant (p > 0.05). Specifically, the CV of fertilizer uniformity F

_{2}is equal to 2.6, and P

_{2}is equal to 0.0606; the CV of vertical fertilizer uniformity F

_{2}is equal to 1.11, and P

_{2}is equal to 0.4358. This proves that the CV of uniformity Y

_{1}and FDA Y

_{2}have good fitting effects, and there are no other main factors affecting the indicators. For the CV of fertilizer uniformity Y

_{1}, x

_{1}, x

_{3}, x

_{4}, x

_{1}x

_{3}, x

_{2}x

_{3}, x

_{2}x

_{4}, x

_{2}

^{2}, x

_{3}

^{2}, and x

_{4}

^{2}have a very significant impact (p < 0.01), while x

_{2}and x

_{1}x

_{2}have a significant impact (0.01 < p < 0.05). For FDA Y

_{2}, x

_{1}, x

_{3}, x

_{4}, x

_{1}x

_{3}, x

_{2}x

_{3}, x

_{2}x

_{4}, x

_{2}

^{2}, x

_{3}

^{2}, and x

_{4}

^{2}have a significant impact (p < 0.01), while x

_{2}, x

_{1}x

_{2}, and x

_{1}

^{2}have a significant impact (0.01 < p < 0.05). The analysis shows that the sequence of factors affecting the CV and FDA is the operation frequency of the SRC, the FGPB, the wedge angle of the PMPB, and the inclination angle of the APP.

#### 3.2. Analysis of Simulation Results of Key Component

#### 3.2.1. Analysis of Factors Influencing Effects

_{1}of the PMPB, CV Y

_{1}first increases, then reaches a peak, and finally remains flat. When the wedge angle α

_{1}of the PMPB reaches 45°, CV Y

_{1}reaches a peak. With the increase in the inclination angle δ of the APP, the CV of uniformity first increases and then decreases. When the inclination angle of the APP is ~44.5–46.5°, the CV of uniformity reaches its optimal value.

#### 3.2.2. Optimization of Key Component Parameters

#### 3.3. Bench Test Results

#### 3.3.1. Test Results

#### 3.3.2. Results of Fertilizer Discharge Performance Tests at Different Frequencies

#### 3.3.3. Fertilizer Crushing Rate Test Results at Different Frequencies

#### 3.4. Adaptability Test Results

## 4. Discussion

_{1}, x

_{2}, x

_{3}, and x

_{4}were determined: the wedge angle x

_{1}of the PMPB was 45°, the tilt angle x

_{2}of the APP was 46°, the FGPB x

_{3}of the SRC was 4.5 mm, and the combined operation frequency x

_{4}of the SRC was 188 times/min. At this point, the model predicted that the CV of fertilizer uniformity would be 10.53%, and that the FDA would be 3.19%. Finally, bench tests were conducted using the optimal parameters to verify the working effect of the optimized fertilizer-discharge device. The CV of fertilizer uniformity in the bench test was 11.06%, with a fertilizer accuracy of 3.51%. The relative error between the CV of fertilizer uniformity in the simulation test and the bench test was 0.53%, and the relative error between the FDA was 0.32%.

## 5. Conclusions

## Author Contributions

## Funding

## Institutional Review Board Statement

## Data Availability Statement

## Conflicts of Interest

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**Figure 1.**The structure and working process of disturbed fertilizer strip-ejection device with vertical pendulum bar: (

**a**) The structure of DFSD: 1 Fertilizer-discharge box; 2 Eccentric pin; 3 Housing; 4 Push-disturbance main pendulum bar; 5 Aided-stirring pendulum pick I; 6 Aided-stirring pendulum pick II; 7 Fertilizer-discharge port; 8 Guide pin; 9 Closed door; 10 Fastening bolt; 11 Shaft pad; 12 Washer; 13 Articulation bit; (

**b**) The working process of DFSD: 1 Fertilizer flow; 2 Fertilizer-discharge box; 3 Aided-stirring pendulum pick I; 4 Aided-stirring pendulum pick II; 5 The main pendulum bar; 6 Guide needle.

**Figure 2.**Schematic diagram of the combined motion analysis with swing rod combination and motion analysis of APP: (

**a**) Schematic diagram of SRC: r, the crank radius; L

_{1}, the length of connecting rod; L

_{2}the distance between the crank rotation center O and the movement point A; r

_{0}, the length of the rocker arm; r

_{1}, the length of main swing bar; β

_{0}, the swing angle; L is the distance between the crank rotation center O and the swing center O

_{1}; α, the crank rotation angle; ω

_{0}, the crank angle velocity; β, the angular displacement of main swing bar (swing angle); α

_{0}, the angle between L

_{2}and the horizontal plane; β

_{1}, the angle between the main pendulum and the horizontal plane at the point of motion A; γ, the angle between L and the horizonta; ξ, the angle between the main pendulum and the horizontal at dead center A

_{2}; ω, the angular velocity of main swing bar; S, displacement of main swing rod end; V, the speed at the end of main swing bar; (

**b**) Motion diagram of aided-stirring pendulum pick I and II. Note: B and C are the endpoint positions at the two wings of the aided-stirring pendulum pick.

**Figure 3.**Schematic analysis of the dynamics of the main pendulum for pushing disturbance: (

**a**) Schematic diagram for force analysis of main swing rod end swinging from dead point OB to center OA

_{3}; (

**b**) Schematic diagram of force analysis of main swing rod end moving from center OA

_{3}to dead point OC.

**Figure 4.**Variation of fertilizer discharge volume within the working stroke of the pendulum combination.

**Figure 6.**Schematic diagram of deflector pin structure (including FGPB): 1 Aided-stirring pendulum pick II; 2 Aided-stirring pendulum pick I; 3 Push-disturbing main pendulum bar; 4 Guide needle.

**Figure 9.**Discrete element-simulation process of disturbed fertilizer strip-ejection device with vertical pendulum bar: 1 Area I; 2 Push-disturbing main pendulum bar; 3 Aided-stirring pendulum pick I; 4 Aided-stirring pendulum pick II; 5 Area II; 6. Area III.

**Figure 10.**Simulation results of fertilizer particle movement: (

**a**) Swing rod combination is stationary; (

**b**) Swing rod assembly moves from center to left; (

**c**) The swing bar assembly moves from the left area to the center; (

**d**) The swing bar assembly moves from the center to the right; (

**e**) The swing bar assembly moves from the right area to the center; (

**f**) The fertilizer removal effect.

**Figure 11.**Analysis of fertilizer-particle simulation results: (

**a**) Discharge fertilizer tank force change curve; (

**b**) Velocity versus time curve of granular fertilizer movement.

**Figure 12.**Grid settings diagram. Note: The 8 statistical grids in each cell are numbered as a~h in the positive region.

**Figure 13.**Bench test: 1 Frame; 2 Fertilizer discharge device; 3 Electronic scale; 4 Motor 5 Power supply serial port; 6 Electronic speed controller; 7 Fertilizer; 8 Moisture content detector; 9 Data-acquisition interface; 10 Plastic basin.

**Figure 14.**The influence rule of each test factor on the CV of uniformity: (

**a**) Y

_{1}= f (X

_{1}, X

_{2}, 0, 0); (

**b**) Y

_{1}= f (X

_{1}, 0, X

_{3}, 0); (

**c**) Y

_{1}= f (0, X

_{2}, X

_{3}, 0); (

**d**) Y

_{1}= f (0, X

_{2}, 0, X

_{4}).

**Figure 15.**The influence rule of various experimental factors on fertilization accuracy: (

**a**) Y

_{2}= f (X

_{1}, X

_{2}, 0, 0); (

**b**) Y

_{2}= f (X

_{1}, 0, X

_{3}, 0); (

**c**) Y

_{2}= f (0, X

_{2}, X

_{3}, 0); (

**d**) Y

_{2}= f (0, X

_{2}, 0, X

_{4}).

Project | Parameter | Unit | Values |
---|---|---|---|

Fertilizer granules | Poisson’s ratio | / | 0.25 |

Shear modulus | pa | 2.6 × 10^{7} | |

Density | kg/m^{3} | 1861 | |

Fertilizer-discharge box and swing rod combination | Poisson’s ratio | / | 0.394 |

Shear modulus | pa | 1.3 × 10^{9} | |

Density | kg/m^{3} | 1240 | |

Fertilizer granules and fertilizer granules | Restitution | / | 0.11 |

Static friction coefficient | / | 0.30 | |

Rolling friction coefficient | / | 0.10 | |

Fertilizer granules, fertilizer-discharge box, and swing-rod combination | Restitution | / | 0.41 |

Static friction coefficient | / | 0.32 | |

Rolling friction coefficient | / | 0.18 |

Parameter | Unit | Value |
---|---|---|

Time step | s | 9.25 × 10^{−6} |

Acceleration | m·s^{−2} | 0 |

Stiffness and damping coefficient | / | 0 |

Local damping coefficient | / | 0 |

Levels | Wedge Angle of PMPB X _{1}/(°) | Inclination Angle of APP X _{2}/(°) | Operating Frequency of SRC X _{3}/(times/min) | FGPB X _{4}/mm |
---|---|---|---|---|

−2 | 35.00 | 40.00 | 100.00 | 3.00 |

−1 | 40.00 | 42.50 | 125.00 | 4.25 |

0 | 45.00 | 45.00 | 150.00 | 5.50 |

1 | 50.00 | 47.50 | 175.00 | 6.75 |

2 | 55.00 | 50.00 | 200.00 | 8.00 |

Test No. | Experimental Factors | Test Index | ||||
---|---|---|---|---|---|---|

x_{1}/(°) | x_{2}/(°) | x_{3}/(times/min) | x_{4}/mm | Y_{1}/% | Y_{2}/% | |

1 | −1 | −1 | −1 | −1 | 6.50 | 1.56 |

2 | 1 | −1 | −1 | −1 | 19.92 | 4.86 |

3 | −1 | 1 | −1 | −1 | 24.16 | 5.85 |

4 | 1 | 1 | −1 | −1 | 23.41 | 5.52 |

5 | −1 | −1 | 1 | −1 | 14.71 | 3.28 |

6 | 1 | −1 | 1 | −1 | 11.61 | 3.22 |

7 | −1 | 1 | 1 | −1 | 17.04 | 4.42 |

8 | 1 | 1 | 1 | −1 | 14.70 | 3.84 |

9 | −1 | −1 | −1 | 1 | 17.59 | 4.20 |

10 | 1 | −1 | −1 | 1 | 29.00 | 5.85 |

11 | −1 | 1 | −1 | 1 | 20.36 | 4.19 |

12 | 1 | 1 | −1 | 1 | 25.82 | 5.45 |

13 | −1 | −1 | 1 | 1 | 22.72 | 5.31 |

14 | 1 | −1 | 1 | 1 | 19.09 | 4.73 |

15 | −1 | 1 | 1 | 1 | 16.04 | 4.20 |

16 | 1 | 1 | 1 | 1 | 11.61 | 3.22 |

17 | −2 | 0 | 0 | 0 | 23.89 | 5.19 |

18 | 2 | 0 | 0 | 0 | 33.41 | 7.16 |

19 | 0 | −2 | 0 | 0 | 12.40 | 2.92 |

20 | 0 | 2 | 0 | 0 | 21.01 | 4.03 |

21 | 0 | 0 | −2 | 0 | 25.97 | 5.30 |

22 | 0 | 0 | 2 | 0 | 15.35 | 3.62 |

23 | 0 | 0 | 0 | −2 | 8.21 | 2.19 |

24 | 0 | 0 | 0 | 2 | 19.13 | 3.80 |

25 | 0 | 0 | 0 | 0 | 31.73 | 7.17 |

26 | 0 | 0 | 0 | 0 | 30.29 | 6.84 |

27 | 0 | 0 | 0 | 0 | 31.73 | 7.17 |

28 | 0 | 0 | 0 | 0 | 27.41 | 6.18 |

29 | 0 | 0 | 0 | 0 | 31.73 | 7.17 |

30 | 0 | 0 | 0 | 0 | 27.41 | 6.18 |

31 | 0 | 0 | 0 | 0 | 30.29 | 6.84 |

32 | 0 | 0 | 0 | 0 | 32.41 | 7.56 |

33 | 0 | 0 | 0 | 0 | 30.73 | 7.17 |

34 | 0 | 0 | 0 | 0 | 32.41 | 7.56 |

35 | 0 | 0 | 0 | 0 | 30.29 | 6.84 |

36 | 0 | 0 | 0 | 0 | 30.73 | 7.17 |

Index | Source | Sum of Squares | Freedom | F | p |
---|---|---|---|---|---|

Y_{1} | Model | 1982.12 | 11 | 34.21 | <0.0001 ** |

x_{1} | 51.28 | 1 | 9.74 | 0.0047 ** | |

x_{2} | 35.58 | 1 | 6.75 | 0.0157 * | |

x_{3} | 152.41 | 1 | 28.94 | <0.0001 ** | |

x_{4} | 112.75 | 1 | 21.41 | 0.0001 ** | |

x_{1}x_{2} | 25.4 | 1 | 4.82 | 0.038 * | |

x_{1}x_{3} | 115.78 | 1 | 21.98 | <0.0001 ** | |

x_{2}x_{3} | 54.32 | 1 | 10.31 | 0.0037 ** | |

x_{2}x_{4} | 105.78 | 1 | 20.08 | 0.0002 ** | |

x_{2}^{2} | 444.67 | 1 | 84.43 | <0.0001 ** | |

x_{3}^{2} | 240.06 | 1 | 45.58 | <0.0001 ** | |

x_{4}^{2} | 644.11 | 1 | 122.3 | <0.0001 ** | |

Residual | 126.4 | 24 | |||

Lack of fit | 95.35 | 13 | 2.6 | 0.0606 | |

Error | 31.06 | 11 | |||

Sum | 2108.53 | 35 | |||

Y_{2} | Model | 91.23 | 12 | 36.12 | <0.0001 ** |

x_{1} | 2.42 | 1 | 11.49 | 0.0025 ** | |

x_{2} | 1.45 | 1 | 6.89 | 0.0151 * | |

x_{3} | 3.1 | 1 | 14.71 | 0.0008 ** | |

x_{4} | 2.55 | 1 | 12.11 | 0.002 ** | |

x_{1}x_{2} | 1.53 | 1 | 7.25 | 0.013 * | |

x_{1}x_{3} | 4.08 | 1 | 19.39 | 0.0002 ** | |

x_{2}x_{3} | 1.82 | 1 | 8.66 | 0.0073 ** | |

x_{2}x_{4} | 5.93 | 1 | 28.17 | <0.0001 ** | |

x_{1}^{2} | 1.15 | 1 | 5.48 | 0.0283 * | |

x_{2}^{2} | 23.93 | 1 | 113.7 | <0.0001 ** | |

x_{3}^{2} | 12.24 | 1 | 58.17 | <0.0001 ** | |

x_{4}^{2} | 31.03 | 1 | 147.45 | <0.0001 ** | |

Residual | 4.84 | 23 | |||

Lack of fit | 2.65 | 12 | 1.11 | 0.4358 | |

Error | 2.19 | 11 | |||

Sum | 96.07 | 35 |

_{1}, x

_{2}, x

_{3}and x

_{4}are the level values of X

_{1}, X

_{2}, X

_{3}, X

_{4}. * indicates significant difference (p < 0.05), ** indicates highly significant difference (p < 0.01).

No. | Y_{1}/% | Y_{2}/% |
---|---|---|

1 | 10.71 | 3.45 |

2 | 11.89 | 3.77 |

3 | 11.42 | 4.18 |

4 | 10.53 | 2.98 |

5 | 10.77 | 3.17 |

average value | 11.06 | 3.51 |

Operating Frequency of SRC X _{3}/(times/min) | Y_{1}/% | Y_{2}/% |
---|---|---|

100 | 14.17 | 4.76 |

120 | 12.36 | 4.33 |

140 | 12.24 | 4.26 |

160 | 11.68 | 3.98 |

180 | 11.39 | 3.68 |

200 | 10.84 | 4.12 |

Fertilizer Types | Equivalent Diameter/mm | Density (kg·m^{−3}) | Sphericity/% | Angle of Repose/° |
---|---|---|---|---|

Lanjingling | 3.08 | 820.14 | 94 | 27.7 |

Changqingshu | 3.19 | 1122.5 | 92 | 29.3 |

Shidanli | 3.44 | 915.3 | 83 | 33.9 |

**Table 9.**Analysis of the adaptability of the fertilizer discharge device to three varieties of granular fertilizers.

Projects | Y_{1}/% | Y_{2}/% | |
---|---|---|---|

Lanjingling | 1 | 9.93 | 3.71 |

2 | 9.74 | 3.69 | |

3 | 9.94 | 3.64 | |

Average value | 9.87 | 3.68 | |

Changqingshu | 1 | 10.51 | 3.75 |

2 | 10.25 | 3.69 | |

3 | 10.77 | 3.27 | |

Average value | 10.51 | 3.57 | |

Shidanli | 1 | 10.87 | 3.52 |

2 | 10.77 | 3.51 | |

3 | 11.15 | 3.65 | |

Average value | 10.93 | 3.56 |

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## Share and Cite

**MDPI and ACS Style**

Chen, L.; Deng, X.; Liu, Z.; Mou, X.; Ma, X.; Chen, R.
Design and Test of Disturbed Fertilizer Strip-Ejection Device with Vertical Pendulum Bar Based on Discrete Element Method. *Agriculture* **2024**, *14*, 635.
https://doi.org/10.3390/agriculture14040635

**AMA Style**

Chen L, Deng X, Liu Z, Mou X, Ma X, Chen R.
Design and Test of Disturbed Fertilizer Strip-Ejection Device with Vertical Pendulum Bar Based on Discrete Element Method. *Agriculture*. 2024; 14(4):635.
https://doi.org/10.3390/agriculture14040635

**Chicago/Turabian Style**

Chen, Lintao, Xiangwu Deng, Zhaoxiang Liu, Xiangwei Mou, Xu Ma, and Rui Chen.
2024. "Design and Test of Disturbed Fertilizer Strip-Ejection Device with Vertical Pendulum Bar Based on Discrete Element Method" *Agriculture* 14, no. 4: 635.
https://doi.org/10.3390/agriculture14040635