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 th...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℃ 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℃/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 di- rection. 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.展开更多
The gas flow from tuyere to raceway zone by blasting involves three distributional zones, such as dripping, cohesive, and lumpy zone. The gas flow distribution in lumpy zone directly affects the gas utilization ration...The gas flow from tuyere to raceway zone by blasting involves three distributional zones, such as dripping, cohesive, and lumpy zone. The gas flow distribution in lumpy zone directly affects the gas utilization ration and smooth operation in the blast furnace. However, the furnace closeness brings about great difficulty in the study of high-temperature gas flow. The charging and blasting system affecting the gas flow and whether the top gas flow distribution could reflect its inner condition as well as the furnace state, such as hanging or scaffolding, which have become the main problems for the research on gas flow. Recently, several researches overseas studied gas flow distribution using the numerical simulation method; however, such a research was rare amongst the natives. In this study, the flow model of gas in cohesive and lumpy zone was established using the numerical simulation software and the gas flow distributions with uniform distribution of burden permeability, scaffolding of wall, and nonuniform charge level were analyzed. As a result, the effects of cohesive zone and lower parts on the gas flow are very limited and the charge level largely affects the distribution of top gas flow. Therefore, it was found that the distribution of top gas flow could hardly reflect the inner gas flow. The process is called ＂redistribution＂ effect, which means that the gas flow after passing through the raceway, dripping, and cohesive zone is distributed when it flows into the lumpy zone.展开更多
基金supported by the National Natural Science Foundation of China (No.60672145)
文摘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℃ 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℃/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 di- rection. 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.
基金Item Sponsored by National Natural Science Foundation of China (60472095)
文摘The gas flow from tuyere to raceway zone by blasting involves three distributional zones, such as dripping, cohesive, and lumpy zone. The gas flow distribution in lumpy zone directly affects the gas utilization ration and smooth operation in the blast furnace. However, the furnace closeness brings about great difficulty in the study of high-temperature gas flow. The charging and blasting system affecting the gas flow and whether the top gas flow distribution could reflect its inner condition as well as the furnace state, such as hanging or scaffolding, which have become the main problems for the research on gas flow. Recently, several researches overseas studied gas flow distribution using the numerical simulation method; however, such a research was rare amongst the natives. In this study, the flow model of gas in cohesive and lumpy zone was established using the numerical simulation software and the gas flow distributions with uniform distribution of burden permeability, scaffolding of wall, and nonuniform charge level were analyzed. As a result, the effects of cohesive zone and lower parts on the gas flow are very limited and the charge level largely affects the distribution of top gas flow. Therefore, it was found that the distribution of top gas flow could hardly reflect the inner gas flow. The process is called ＂redistribution＂ effect, which means that the gas flow after passing through the raceway, dripping, and cohesive zone is distributed when it flows into the lumpy zone.
