Erosion analysis and improvement of curved-tee in pneumatic conveying system

doi:10.11949/0438-1157.20250127

Abstract

Abstract:

The curved-tee in the pneumatic conveying system of a petrochemical enterprise is composed of a tee and a 45° elbow. It had leakage failure problems many times during operation. The CFD-DPM numerical simulation method was used to study the erosion law of the curved-tee and to analyze the influence of the flow field on the particle trajectory, which resulted in the erosion behavior of the particles on the target material. The results show that there is a coupling between the influence of tee and elbow on the particle trajectory. The severe erosion zone is mainly distributed in the front wall of the elbow and has a distinctive curved feature. The branch gas has a “gathering” effect on the particles, which aggravates the erosion damage of the curved-tee. Finally, it is suggested that significant erosion relief can be achieved by moving the branch pipe downwards or using a small angle elbow.

Key words: pneumatic conveying, particle, curved-tee, CFD, erosion

摘要：

某石化企业气力输送系统弯管三通由三通和45°弯头连接组成，在运行过程中多次出现泄漏失效问题。采用CFD-DPM数值模拟方法研究了弯管三通的冲蚀规律，分析了流场对颗粒轨迹的影响及颗粒对靶材的冲蚀行为。结果表明，三通和弯头对颗粒轨迹的影响存在耦合。严重冲蚀区主要分布在弯头前壁，而且具有鲜明的弧形特征。支管气体对颗粒具有“聚集”效应，加剧了弯管三通的冲蚀损伤。最后，提出通过下移支管或采用小角度弯头，可以显著缓解冲蚀。

关键词: 气力输送, 粒子, 弯管三通, 计算流体力学, 冲蚀

CLC Number:

TE 986

Guoqing SU, Xuemei TIAN, Yan LI, Jianwen ZHANG, Zhijun ZHANG. Erosion analysis and improvement of curved-tee in pneumatic conveying system[J]. CIESC Journal, 2025, 76(8): 3894-3904.

苏国庆, 田学梅, 李彦, 张建文, 张志军. 气力输送系统弯管三通的冲蚀分析及改进[J]. 化工学报, 2025, 76(8): 3894-3904.

Figures/Tables 15

Table 1 Impact angle function

角度/(°)	f(α)
0	0
20	0.8
30	1.0
45	0.5
90	0.4

Fig.1 Physical photograph of the curved-tee

Fig.2 3D model of the curved-tee

Fig.3 Mesh division result

Fig.4 Mesh independence verification

Table 2 Physical parameters of gas and solid phases

入口	物料	速度/(m/s)	质量流量/(kg/s)	密度/(kg/m³)	黏度/cP	直径/μm
入口 1	N₂	8	—	1.85	0.28	—
入口 1	吸附剂	8	0.144	1500	—	75
入口 2	N₂	8	—	1.85	0.28	—
入口 2	吸附剂	8	0.025	1500	—	75

Fig.5 Comparison of different erosion models with actual thinning results

Fig.6 Erosion rate contour of the curved-tee

Fig.7 Velocity contour of different parts of the curved-tee

Fig.8 Surface streamlines of the curved-tee with different cross-sections

Fig.9 Particle concentration contour at different parts of the curved-tee

Fig.10 Particle trajectory in the curved-tee

Fig.11 Schematic diagram of particle movement in the curved-tee

Fig.12 Calculated erosion results for different branch movement distances

Fig.13 Calculation results of erosion under different angle elbows

References 30

[1]	禹言芳, 石博文, 孟辉波, 等. 基于CFD-DEM算法的气力输送气固两相流特性分析[J]. 化工进展, 2024, 43(3): 1133-1144.
	Yu Y F, Shi B W, Meng H B, et al. Characteristics analysis of gas solid two-phase flow in pneumatic conveying based on CFD-DEM algorithm[J]. Chemical Industry and Engineering Progress, 2024, 43(3): 1133-1144.
[2]	苏国庆, 张建文, 李彦. 蝶阀后管线腐蚀发生与发展机制研究[J]. 化工学报, 2022, 73(12): 5504-5516.
	Su G Q, Zhang J W, Li Y. Study on the occurrence and development mechanism of pipeline corrosion behind butterfly valve[J]. CIESC Journal, 2022, 73(12): 5504-5516.
[3]	王硕, 张亚新, 朱博韬. 基于灰色预测模型的水煤浆输送管道冲蚀磨损寿命预测[J]. 化工进展, 2023, 42(7): 3431-3442.
	Wang S, Zhang Y X, Zhu B T. Prediction of erosion life of coal water slurry pipeline based on grey prediction model[J]. Chemical Industry and Engineering Progress, 2023, 42(7): 3431-3442.
[4]	郭姿含, 张军, 黄金满, 等. 具有仿生内表面结构的弯管抗冲蚀特性数值分析[J]. 表面技术, 2023, 52(5): 90-100.
	Guo Z H, Zhang J, Huang J M, et al. Numerical analysis of erosion resistance of elbow with bionic inner surface structure[J]. Surface Technology, 2023, 52(5): 90-100.
[5]	邱福寿, 王国涛, 彭辉, 等. 含凹坑缺陷稠油热采井口用四通管的冲蚀数值模拟研究[J]. 压力容器, 2021, 38(2): 28-36, 54.
	Qiu F S, Wang G T, Peng H, et al. The erosion numerical simulation analysis of the four-way pipe with pit defect used in the heavy oil thermal production wellhead[J]. Pressure Vessel Technology, 2021, 38(2): 28-36, 54.
[6]	Wang C, Duan A Q, Xu J, et al. Cavitation failure analysis of 90-degree elbow of mixing point in ethylene glycol recovery and concentration system[J]. Engineering Failure Analysis, 2021, 125: 105400.
[7]	亢嘉妮, 何立东, 范文强, 等. 环氧乙烷装置T形三通管件故障原因分析与改进[J]. 化工进展, 2021, 40(S1): 32-42.
	Kang J N, He L D, Fan W Q, et al. Cause analysis and improvement of T-shaped tee fittings in ethylene oxide plant[J]. Chemical Industry and Engineering Progress, 2021, 40(S1): 32-42.
[8]	张建文, 苏国庆, 姜爱国. 液化气脱硫装置再生塔返塔管线弯头腐蚀失效机制分析[J]. 化工学报, 2018, 69(8): 3537-3547.
	Zhang J W, Su G Q, Jiang A G. Corrosion failure mechanism of return pipeline elbow of regeneration tower in LPG desulfurization unit[J]. CIESC Journal, 2018, 69(8): 3537-3547.
[9]	Finnie I. Erosion of surfaces by solid particles[J]. Wear, 1960, 3(2): 87-103.
[10]	Bitter J G A. A study of erosion phenomena(part Ⅰ)[J]. Wear, 1963, 6(1): 5-21.
[11]	Levy A V. The erosion of structural alloys, cermets and in situ oxide scales on steels[J]. Wear, 1988, 127(1): 31-52.
[12]	Sheldon G L. Effects of surface hardness and other material properties on erosive wear of metals by solid particles[J]. Journal of Engineering Materials and Technology, 1977, 99(2): 133-137.
[13]	Bilal F S, Sedrez T A, Shirazi S A. Experimental and CFD investigations of 45 and 90 degrees bends and various elbow curvature radii effects on solid particle erosion[J]. Wear, 2021, 476: 203646.
[14]	Zhu H J, Pan Q, Zhang W L, et al. CFD simulations of flow erosion and flow-induced deformation of needle valve: effects of operation, structure and fluid parameters[J]. Nuclear Engineering and Design, 2014, 273: 396-411.
[15]	Khan R, Petru J, Seikh A H. Erosion prediction due to micron-sized particles in the multiphase flow of T and Y pipes of oil and gas fields[J]. International Journal of Pressure Vessels and Piping, 2023, 206: 105041.
[16]	郑云萍, 王欢欢, 易昊林, 等. 天然气管道弯头冲蚀与防护仿真研究[J]. 计算机仿真, 2015, 32(8): 427-430.
	Zheng Y P, Wang H H, Yi H L, et al. Simulation of erosion-corrosion for different angles of gas pipeline elbows[J]. Computer Simulation, 2015, 32(8): 427-430.
[17]	Sommerfeld M, Huber N. Experimental analysis and modelling of particle-wall collisions[J]. International Journal of Multiphase Flow, 1999, 25(6/7): 1457-1489.
[18]	Zhang J X, Kang J, Fan J C, et al. Study on erosion wear of fracturing pipeline under the action of multiphase flow in oil & gas industry[J]. Journal of Natural Gas Science and Engineering, 2016, 32: 334-346.
[19]	Boroughani B, Shahi A, Ansari Arab M, et al. Failure investigation of a tee used in sour gas transmission piping service[J]. Engineering Failure Analysis, 2022, 140: 106401.
[20]	Farokhipour A, Mansoori Z, Rasoulian M A, et al. Study of particle mass loading effects on sand erosion in a series of fittings[J]. Powder Technology, 2020, 373: 118-141.
[21]	Xu L, Chen X C, Wu X K, et al. Coarse-grained CFD-DEM simulation of elbow erosion induced by dilute gas-solid flow: a multi-level study[J]. Powder Technology, 2024, 443: 119916.
[22]	杨利民. 两相流新型分离器: T形三通管的研究进展[J]. 化工进展, 2008, 27(1): 45-49.
	Yang L M. Research advances in a new phase separator of two-phase flows: T-junction[J]. Chemical Industry and Engineering Progress, 2008, 27(1): 45-49.
[23]	Zhao X Y, Cao X W, Zhang J N, et al. Experimental and numerical investigation of erosion in plugged tees for liquid-solid flow[J]. International Journal of Multiphase Flow, 2023, 160: 104348.
[24]	Yao L M, Liu Y X, Xiao Z M, et al. Investigation on tee junction erosion caused by sand-carrying fracturing fluid[J]. Tribology International, 2023, 179: 108157.
[25]	Zhao Y L, Tang C Y, Yao J, et al. Investigation of erosion behavior of 304 stainless steel under solid-liquid jet flow impinging at 30°[J]. Petroleum Science, 2020, 17(4): 1135-1150.
[26]	Cui B C, Chen P, Zhao Y Q. Numerical simulation of particle erosion in the vertical-upward-horizontal elbow under multiphase bubble flow[J]. Powder Technology, 2022, 404: 117437.
[27]	Sedrez T A, Shirazi S A. Erosion evaluation of elbows in series with different configurations[J]. Wear, 2021, 476: 203683.
[28]	Zhou H, Zhang Y, Bai Y, et al. Study on reducing elbow erosion with swirling flow[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2021, 630: 127537.
[29]	Banakermani M R, Naderan H, Saffar-Avval M. An investigation of erosion prediction for 15° to 90° elbows by numerical simulation of gas-solid flow[J]. Powder Technology, 2018, 334: 9-26.
[30]	Ajmal T S, Arya S B, Maurya P, et al. Effect of hydrodynamics and laser surface melting on erosion-corrosion of X70 steel pipe elbow in oilfield slurry[J]. International Journal of Pressure Vessels and Piping, 2022, 199: 104687.