＜正＞So far, there are two widely used approaches to calculate different regions’ volume fraction for single-str...
PAN Hong-wei~1 CHENG Shu-sen~1 CHENG Zi-jian~(1,2) 1.School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083,China
The key to reduce shell breakout in the continuous casting process is to control shell thickness in the mold. A numerical simulation on the turbulent flow and heat transfer coupled with solidification in the slab mold using the volume of fluid(VOF) model and the enthalpy-porosity scheme was conducted and the emphasis was put upon the flow effect on the shell thickness profiles in longitudinal and transverse directions. The results show that the jet acts a stronger impingement on the shell of narrow face,which causes a zero-increase of shell thickness in a certain range near the impingement point. The thinnest shell on the slab cross-section locates primarily in the center of the narrow face,and secondly near the corner of the wide face. Nozzle optimization can obviously increase the shell thickness and make it more uniform.
The temperature of gas flow inside a blast furnace(BF) changes significantly when the blast furnace is under unstable operations,and the temperature and stress distributions of cooling staves(CS) for BF work the same pattern.The effect of gas temperature on the temperature,stress,and displacement distributions of the cooling stave were analyzed as the gas temperature inside the blast furnace rose from 1000 to 1600°C in 900 s.The results show that both the temperature and temperature gradient of the hot side of CS increase when the gas flow temperature inside BF rises.The temperature gradient of the hot side of CS is greater than that of the other area of CS and it can reach 65°C/mm.In the vertical direction of the hot side of CS,closer to the central part of CS,the stress intensity is greater than that of the other area of the hot side of CS,which causes cracks on the hot side of CS in the vertical direction.As the gas temperature increases,the stress intensity rate near the fixed pin increases and finally reaches 45 MPa/s.Fatigues near the fixed pin and bolts are caused by great stress intensity rate and the area around the pin can be damaged easily.The edge of CS bends toward the cold side and the central part of CS shifts toward the hot surface.
