Flow field analysis and inlet angle optimization of underwater pelletizer based on CFD⁃DPM

doi:10.19491/j.issn.1001-9278.2025.06.010

Abstract

Abstract:

Based on the simulation method of CFD⁃DPM， we analyzed the particle flow state and the number of particles escaping from the water chamber of the underwater pelletizer under different inlet angles， and studied the average number of particles escaping from the water chamber within the same time change at different inlet angles， and then determined the optimal inlet angle of the water chamber by using the curve fitting method of cubic spline interpolation. The results show that when the inlet of the water chamber of the underwater pelletizer is set at 80° （the inlet of the prototype is rotated counterclockwise by 10°）， the average number of particles escaping from the outlet of the water chamber is the largest within the same time change.

Key words: CFD?DPM, number of escapes, cubic spline interpolation, optimal inlet angle, pelletizer

CLC Number:

TQ320

GUAN Hongyan, YANG Wenqiang, ZHANG Guoqiang. Flow field analysis and inlet angle optimization of underwater pelletizer based on CFD⁃DPM[J]. China Plastics, 2025, 39(6): 48-53.

Figures/Tables 13

Fig.1. Geometric model of pelletizing water chamber

进口内直径/mm

出口内直径/mm

中室圆直径/mm

水室厚度/

内部凸起高度/

刀盘面直径/

刀盘轴径/

刀盘凸起高度/

刀刃尺寸

/mm

切刀数量

/个

×

×

进口内直径/mm

出口内直径/mm

中室圆直径/mm

水室厚度/

内部凸起高度/

刀盘面直径/

刀盘轴径/

刀盘凸起高度/

刀刃尺寸

/mm

切刀数量

/个

235

275

1050

380

540

140

×

×

Tab.1. Model size parameters

多面体网格

静止域/

旋转域/

Tab.2. Mesh size division

Fig.2. mesh independence verification

Fig.3. model computational domain mesh

Fig.4. Vector and particle trace map at Z=-192.5 mm

Fig.5. Water chamber model after outlet optimization

Fig.6. Water chamber model after outlet optimization

Fig.7. Plot of changes in the number of particles escaping

进口角度/（°）	0 °	15 °	30 °	45 °	60 °	75 °	90 °
颗粒平均数/颗	1 363	1 245	1 354	1 278	1 204	1 355	1 271

Tab.3. Mean values of the total number of particles escaping in 0.3 s at multiple inlet angles

Fig.8. Multiple ways to fit curves

Fig.9. 80° inlet water chamber model

Fig.10. 80° Import Comparison Verification Chart

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