Study on feeding performance of screw feeder based on discrete element simulation

doi:10.19491/j.issn.1001-9278.2024.09.011

Abstract

Abstract:

A series of screw structures with different screw leads， outer diameters， and head numbers were established by using a modeling software. After the particle model was established and the contact parameters were set in the discrete element numerical simulation software， the conveying process of screw under different structures was simulated. The post⁃treatment module was used to analyze the force of particles in the conveying process and the mass flow rate at the outlet of the feeder， and the effect of screw structure on the feeding quality was discussed. The results indicated that the screw lead was the main factor affecting the conveying efficiency of the screw feeder. The conveying efficiency of the screw with the 20 mm lead was about 15 times as high as that with the 14mm lead； however， the discharging accuracy was reduced. The screw clearance is the main factor affecting the force of particles. The decrease of the clearance can lead to an increase in the force of particles. The average force of the screw clearance is about 1.2×10^-2 N. The double⁃headed screw caused the surge of force in the particle conveying process， resulting in a peak value of about 15 N. Meanwhile， the discharge efficiency was reduced， but the discharge stability was improved.

Key words: feeding quality, screw structure, discrete element simulation, screw feeder

CLC Number:

TQ320.66⁺3

ZHOU Shengrong, WAN Zhou, WANG Yu, LI Guo, MA Yulu, XIE Linsheng. Study on feeding performance of screw feeder based on discrete element simulation[J]. China Plastics, 2024, 38(9): 60-65.

Figures/Tables 15

Fig.1. Main geometric discrete model of metering and feeding device

Fig.2. Particle prototype and fitting coordinate center

球标号	X/mm	Y/mm	Z/mm	半径/mm
0	-0.452 9	-0.018 0	-0.006 7	0.467 9
1	0.347 2	-0.034 1	-0.009 8	0.501 4
2	0.102 3	0.375 3	0.025 3	0.367 7
3	0.075 7	-0.460 6	0.056 7	0.281 5

Tab.1. Fitting spherical dimensions and positions

颗粒标号	与原型颗粒的尺寸比	在颗粒群中的质量占比
1	0.5	14
2	0.9	45
3	1.4	37
4	1.9	4

Tab.2. The size type and mass proportion of the simulated particles

材料	参数	参数值
物料	泊松比	0.215
	密度/kg·m^-3	1 500
	剪切模量/Pa	5×10⁶
45^#钢	泊松比	0.25
	密度/kg·m^-3	7 800
	剪切模量/Pa	7×10¹⁰
物料⁃物料	碰撞恢复系数	0.2
	静摩擦因数	0.3
	滚动摩擦因数	0.1
45^#钢⁃物料	碰撞恢复系数	0.2
	静摩擦因数	0.5
	滚动摩擦因数	0.1

Tab.3. Material parameter settings

变化参数	仿真编号	间隙/mm	头数	导程/mm
螺杆导程	1	2	1	20
螺杆导程	2	2	1	14
螺杆间隙	3（2）	2	1	14
	4	1.5	1	14
	5	1	1	14
螺杆头数	6（2）	2	1	20
螺杆头数	7	2	2	20

Tab.4. Screw dimension parameters

Fig.3. Influence of screw lead on force of material particles

Fig.4. Cloud picture of particle position of material with large contact force under different leads

Fig.5. Influence of the clearance between screw and cylinder on the force of particles

Fig.6. Cloud map of distribution of material particles with greater force under different gaps

Fig.7. Influence of the number of screw heads on the force of particles

Fig.8. Effect of the number of screw heads on the force distribution of particles

Fig.9. Influence of screw lead on particle outlet quality change

Fig.10. Influence of screw and barrel clearance on the change of material particle outlet quality

Fig.11. Effect of number of screw heads on quality change of material particles at outlet

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