A new dust removal technology used in hot rolling mills: Atomized spray with higher dedusting efficiency

摘要

In order to effectively remove the oxide scale dusts in the hot rolling strip steel, this study focuses on the principle of atomized spray and use it to develop a new dust removal technology used in the hot rolling mills. Through establishing a mathematic model of particle collision, 4 critical factors most affecting the dedusting efficiency are analysed: the diameter of nozzles, the diameter of water droplets, the diameter of dust particles, and the spray pressure. For further discovering the principles of the movements and concentration changes of the dust particles, a numerical model is established based on the gap space between the hot rolling mills. 2 scenarios of running the atomized dedusting or not are simulated to compute the dedusting efficiency so that the dedusting effect of the atomized spray can be confirmed for the hot rolling. The case study on the 1580 mm hot rolling line in WISCO plant demonstrates a successful dedusting efficiency of 93.50% on the R2 rough rolling mill. The spray pressure of 0.5 MPa and the nozzle diameter of 1.4 mm are appropriate to generating the proper water droplets with the diameter of 71.1 mu m in order to capture the dust particles with the mean diameter of 27 mu m. The study on the principles and simulations of the atomized spray facilitates more efficient dust removal for cleaner hot rolling mills.