Effect of Side Blowing on Fluid Flow and Mixing Phenomenon in Gas-Stirred Ladle

Rong Cheng,Liangjin Zhang,Jiongming Zhang,Yanbin Yin

doi:10.3390/met11020369

Rong Cheng, Liangjin Zhang + Show 2 more

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https://doi.org/10.3390/met11020369

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Abstract

To investigate the gas agitation characteristics of side blowing, the fluid flow and mixing phenomenon in a 1:3 scale model ladle of a 150 t industrial gas-stirred ladle with bottom and side plugs were studied by using physical and numerical modelings together. Side blowing enhanced the horizontal flow of water in the model ladle. Compared with bottom blowing, side blowing that is close to the ladle bottom with more than two plugs increases the average velocity of water, which represents the agitation power, improves the uniformity of water velocity distribution, reduces the stagnant region rate, and shortens the mixing time. The mixing time of dual bottom plugs is almost 1.5 times of that of four side plugs at 116 mm under the same flow rate. The mixing time is not only influenced by the agitation power but also by the uniformity of water velocity distribution. Although the agitation power of four side plugs at 450 mm under the flow rate of 1.8 m3/h is about 1.5 times of that at 116 mm with 0.6 m3/h. The mixing time of the 1.8 m3/h flow rate is about 1.2 times of that of the 0.6 m3/h because of the different water velocity distributions.

Highlights

The alloying process is an important target during the secondary refining process
A large number of studies show that the mixing time has commonly been used to represent the gas agitation power in gas-stirred ladles [9,10,11,12,13,14,15,16]
The analysis showed that large mean velocity and turbulent kinetic energy led to a short mixing time

Summary

Introduction

The alloying process is an important target during the secondary refining process. An alloying element could eliminate deleterious effects of other elements in molten steel and improve the physical and mechanical properties of steel products. In studies of Nakanishi [9] and Sinha [10], the relation between mixing time and agitation power were investigated by using a solution of 75% H2SO4 as a tracer in a water model ladle and derived as follows: τm = 800ε−m0.4 [9] and τm = 692ε−m0.89 [10] (where τm and εm correspond to the mixing time and agitation power, respectively). Some researchers [11,12,13,14] correlated the mixing time as simple functions of agitation power, liquid depth, and radius of the ladle with the experiment of tracer homogenization in a water modeling ladle. Zhu [15] and Amaro-Villeda [16] summarized mixing time correlations reported in the literature under different experimental conditions, such as gas flow rates, number of nozzles, nozzle radial position, and thickness of oil

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