LEI Peng¹, SONG Jianfei¹, LI Qiang², WEI Yaodong¹, SUN Guogang¹

(1. College of Mechanical and Transportation Engineering, China University of Petroleum(Beijing), Beijing 102249, China;2. Beijing Aerospace Propulsion Institute, Beijing 100076, China)

Abstract

Objective Cascade-ring aerodynamic dust separator is a type of inertia dust collector that combines many advantages such as stable performance, small space occupation, various installation and arrangement methods and low operation cost. To improve the separation performance of the cascade-ring aerodynamic dust separator, it is necessary to study the effects of structural and operating parameters on the separation efficiency and pressure drop and to determine the optimal structural and operating parameters of the dust separator.

Methods Firstly, a simulation was performed by using RNG k-ε for the flow analysis, with the discrete phase models (DPM) employed to calculate the particle trajectories. The influence of ring displacement, ring height, ring numbers and ring interval distance on separation performance was investigated, and these structural parameters of the dust separator were optimised. Secondly,the dust separator was designed based on the optimised structural parameters, and the experimental platform was built. Finally,the effects of velocity, the ratio of exhausted gas to inlet gas and particle concentration on the separation efficiency and pressure drop of the dust separator were investigated to determine the optimal operating parameters of the dust separator.

Results and Discussion The gas flow passes through the ring seams at the tail of the dust separator at a high gas velocity, the particles escape at the last two ring seams. The highest air velocity at the last ring seam is 57. 88 m/ s, with the the escaped particles generally sized below 22 μm. Notably, the efficiency of the dust separator decreases as the ring displacement increases, and the ring displacement should be 1 mm. The separation efficiency reaches a maximum value of 77. 47% at a ring height of 5 mm, and the ring inclination is about 24°. The pressure drop exhibits an upward trend with increasing ring numbers, reaching a critical drop in the separation efficiency at ring numbers ≥30. Therefore, the recommended ring numbers should be 20. The highest separation efficiency of 79. 2% is achieved with a ring interval distance of 8 mm. However, to avoid the escape of particles from the ring seams of the last few stages, it is advisable to set the ring interval distance of the last few stages at 2 mm. The optimised structural parameters of the dust separator include a cylinder diameter of 150 mm, ring thickness of 20 mm, 20 ring numbers,8 mm ring interval distance of the first 16 rings, 2 mm ring interval distance of the last 4 rings, a ring height of 5 mm, and a ring displacement of 1 mm. Considering the operating parameters, the operating cascade-ring aerodynamic dust separator performs best with a ratio of exhausted gas to gas inlet gas set at 20%, and a gas velocity of 15 m/ s. Under these conditions, the experimental and simulated pressure drop are recorded at 1. 54, 1. 41 kPa, respectively, and the experimental and simulated separation efficiency are measured at 79. 15% and 92. 28%, affirming the efficacy of the optimized parameters.

Conclusion The effect of structural parameters and operation conditions on the separation performance of cascade-ring aerodynamic dust separators are investigated by numerical simulation and experimental research. The highest separation efficiency is achieved under the optimal structural and operating parameters, with simulated results closely aligning with experiment results.Moreover, the variation of particle concentration has little effect on the separation efficiency, indicating that the cascade-ring aerodynamic dust separator is suitable for separating dust particles of different concentrations.

Keywords: cascade-ring aerodynamic dust separator; separation efficiency; pressure drop; numerical simulation

Get Citation:LEI P, SONG J F, LI Q, et al. Numerical simulation and experiments on separation performance of cascade-ring aerodynamic dust separator[J]. China Powder Science and Technology, 2023, 30(1): 144-152.

Received: 2023-07-24,Revised:2023-11-30, Online:2023-12-13。

Funding Project:国家自然科学基金项目,编号:21776305。

First Author:雷鹏(1997—),男,硕士生,研究方向为石油化工过程设备。 E-mail: Leip221@126.com。

Corresponding Author:宋健斐(1979—),女,教授,博士,博士生导师,研究方向为多相流动理论与分离技术。 E-mail: songjf@cup.edu.cn。

CLC No: TB4; TQ051. 8         Type Code:A

Type Code:1008-5548(2024)01-0144-09