Flow Simulation in the Liquid Bath of a Iron Smelting Reduction and Its Water Model Experiments

• Main Authors: Wu, Shiu-Chia, 吳秀佳
• Other Authors: Weng-Sing Hwang
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/11419529040302629609

碩士 === 國立成功大學 === 材料科學(工程)學系 === 86 === In this thesis study, a mathematical model has been developed tosimulate the flow phenomena for gas stirring in the iron bath of the smelter for direct iron ore smelting reduction process. A corresponding water model has also been constructed to observe the flow pattern in the liquid bath system. The flow phenomena of concerns includes flow pattern and mixing time at various rate of gas injection for liquids of different viscosity. To assure the accuracy of the simulation model, the calculated results are also compared with the experimental observation from the water model.To develop the three dimensional fluid flow analysis system, a computational fluid dynamics technique; called SOLA-SURF, and the κ-εtwo equation turbulence model are used to analyze the fluid flow pattern in the smelter. The simulations are performed for liquids of under various rate of gas injection. A water model has also been constructed. Experiments are performed to observe the flow pattern and measure the mixing time under various conditions. To observe the flow pattern, a light page is generated from a laser beam to lighten a certain cross section of the water model. Tracer particles are added to the system and a camera is used to take the pictures of fluid pathlines. Mixing time is also measured by monitoring the change of conductivity with time. The measurements/observations are also used to verify the accuracy of the mathematical model. The mathematical model is tested on a smelter system with four tuyeres blowing gas into the liquid bath from the bottom with the conditions identical to the water model. The results reveal that the liquid flows faster with higher gas flow rate, which results in larger recirculation and higher surface liquid speed near the surface. This in turn has shorter mixing time. The flow fields for liquids with two different viscosities; 1cP and 2 cP respectively, look similar. However, the flow speed is slower and the dead zone is larger for liquid of higher viscosity. These in turn result in higher mixing time and thus less efficient for stirring. The results of the mathematical simulations are compared with the measurements and observations from the water model. They show good consistency. With the developed mathematical model, it can aid to evaluate the effects of processing conditions and viscosity of liquid on the flow conditions of the liquid in the direct iron smelter.