| In the production of iron and steel, users also raise higher and higher requirements for the quality of steel, and reducing the sulfur content in steel has become principal means to ensure the quality of steel products and improve market competitiveness. That the hot metal pre-desulfurization technology has been widely used provides new opportunities for development, and reduces desulfurization task in BF and steelmaking load in BOF, and is conducive to continuous casting production. For improving the efficiency of pretreatment, the technology of magnesium desulfurization has great significance, but due to low utilization of magnesium, magnesium desulfurization can not play the standard expected in the existing magnesium desulfurization process. In magnesium desulfurization process, understanding and controlling fluid behavior in hot metal tank is the key to improve the utilization of magnesium, and the flow field behavior depends on the design of desulfurization lance nozzle, besides, the factors, such as lance nozzle openings direction, opening positional relationship, open-number of holes and opening changes in the cross-sectional area etc, has an important impact on the flow of hot metal tank. Therefore, that studying and optimizing the structures of desulfurization lance nozzle is very necessary.This paper, basing on the lance in the process of magnesium desulfurization, redesigned the different structures of the lance nozzle, and applied respectively physical simulation and mathematical simulation in researching the behavior of the fluid in hot metal tank, besides, optimized the structure of desulfurization lance nozzle.Using the stimulus-response method in physical simulation, this paper studied the impact of the different nozzle structures, such as lance nozzle openings direction, opening positional relationship, open-number of holes and opening changes in the cross-sectional area, on flow state in iron tank fluid. The results showed, the nozzle structure in which opening direction is 45°, and the hole location relationship is eccentric, and opening number is 2-hole, and the cross-sectional area of the hole is enlarged had the shortest mixing time, followed by 20.66s,20.58s,15.87s,15.79s under the gas flow of 1.5m3/h-3.0m3/h, and it shortened by 1.68s?9.25s compared with the mixing time of the original nozzle.Using numerical simulation methods, this paper analysed the properties of flow field which formed in optimal solution and the original proposal. The results showed that the average speed in flow field of the Optimal nozzle improved 0.0055-0.0070m/s than the original nozzle flow, and the average turbulent kinetic energy increased 0.00052?0.00147 m2/s2, and its dead zone area decreased 15.45%?18.34%, and the mixing time of numerical simulation were in good agreement with the results of physical simulation. This paper proceeded numerical simulation about gas-liquid two-phase flow in actual hot metal tank. The results showed that the two-phase flow model basis on the water model experiments could be applied to calculate the numerical model of a real iron tank. The average flow velocity and average turbulent kinetic energy in the original proposal, increased from 0.107m/s and 0.036m2/s2 to 0.124m/s and 0.077m2/s2, and its dead zone area decreased from 10.60% to 4.47%. |
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