Influence of flight structures and baffle dam on particle behaviors and gas-solid heat exchange enhancement in a rotary drum--颗粒学报PARTICUOLOGY

a School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
b Jiangxi Provincial Key Laboratory of Particle Technology, Jiangxi University of Science and Technology, Nanchang, 330013, China
c Research Centre for Intelligent Mineral Processing & Metallurgy, International Institute for Innovation, Jiangxi University of Science and Technology, Nanchang, 330013, China
d Beijing Key Laboratory for Energy Saving and Emission Reduction of Metallurgical Industry, University of Science and Technology Beijing, Beijing, 100083, China

10.1016/j.partic.2025.04.010

Volume 102, July 2025, Pages 104-117

Received 24 January 2025, Revised 22 March 2025, Accepted 11 April 2025, Available online 23 April 2025, Version of Record 3 May 2025.

E-mail: zyjiang@ustb.edu.cn

Highlights

• Separated segmented flights with baffle dam were designed for rotary drum.

• Particle motion was analyzed for various flighted drums with DEM.

• Changes in axial velocity and curtain were demonstrated with long drum model.

• Segmentation and damming for flights can improve heat exchange and its uniformity.

Abstract

In a waste heat recovery rotary drum with flights, particle lifting enhances gas-solid contact and introduces greater complexity to the particle motion. This study proposed strategies such as the segmentation and separation of flights (SSF) and the addition of baffle dams to establish a reasonable distribution of the particle curtain. A long drum model was developed, and DEM was employed to examine the effects of segment length, separation angle of flight, and position, height of baffle dam on particle motion and heat exchange capacity. The heat exchange efficiency of the system under the four special operating conditions was compared. The results showed that SSF enhanced the randomness of particle axial motion, while the development of the long drum model effectively identified the key factors influencing motion. The SSF formed a spiral-shaped particle curtain, exhibiting a high degree of particle distribution uniformity. The installation of the baffle dam enhanced the flight holding capacity and suppressed both transitional particle movement and backflow. With equivalent filling degree, compared to the uninterrupted flight, the SSF with bilateral baffle dam reduced the particle distribution non-uniformity by 61.72 %, while increasing the gas-solid contact area by 3.92 % and the bulk cooling temperature by 1.51 times.

Graphical abstract

Keywords

Waste heat recovery; Rotary drum; Discrete element method (DEM); Flight; Baffle dam; Heat exchange enhancement

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