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THERMAL SCIENCE
International Scientific Journal
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NUMERICAL SIMULATION OF BLOWING PROCESS IN THE OVERAGING SECTION OF A VERTICAL CONTINUOUS ANNEALING FURNACE USING CFD
ABSTRACT
The vertical continuous annealing furnace plays a pivotal role in the annealing treatment line of strip steel. Within this furnace, expelling the air by blowing protective gas is essential. This helps reduce the oxygen content, thereby preventing the formation of oxides and impurities on the surface of the strip steel. This study aims to investigate the influence of the structure of the overaging section of a vertical continuous annealing furnace on the blowing effect. The gas-flow characteristics during the blowing process have also been examined, revealing the location and distribution of stagnant zones. The CFD is used to solve a 3-D simulation model numerically, calculating the flow and velocity of gas within the furnace for blowing ranging from 0 to 100 seconds. The results indicate that the flow field in the furnace reaches a quasi-steady-state at a blowing of approximately 75 seconds. However, the issue of flow field voids and stagnant zones shows negligible improvement beyond this point. The blowing effect varies across different regions of the furnace, with a notable area of flow field void and stagnant zone in the lower part of the furnace, far from the bellows, resulting in a suboptimal blowing effect. The findings of this study can serve as valuable guidance for optimizing the internal structure of a vertical continuous annealing furnace and improving the efficiency of the blowing process.
KEYWORDS
Vertical continuous annealing furnace, Overaging section, velocity field, numerical simulation, Stagnant zone
PAPER SUBMITTED: 2024-11-24
PAPER REVISED: 2025-02-22
PAPER ACCEPTED: 2025-03-12
PUBLISHED ONLINE: 2025-04-05
DOI REFERENCE: https://doi.org/10.2298/TSCI241124067G
CITATION EXPORT: view in browser or download as text file
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© 2026 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence