Blast furnace operation with hot burden charging was numerically simulated to preliminarily analyze its advantages and disadvantages. Multi-fluid blast furnace model was utilized to simulate hot burden charging operat...Blast furnace operation with hot burden charging was numerically simulated to preliminarily analyze its advantages and disadvantages. Multi-fluid blast furnace model was utilized to simulate hot burden charging operations under the conditions that the charging temperatures of pellet and coke were supposed separately or simultaneously as 800℃. The results showed that, with hot burden charging, the furnace top temperature significantly increased in comparison to the conventional operation with cold hurden charging. However, in-furnace temperature decreased, which decelerated the reduction rate of ferrous burdens. The concentrations of reducing gases were decreased in the furnace. The height of cohesive zone shifted downwards. When the charging temperatures of pellet and coke were simultaneously 800 ~C （PC800）, coke rate, fuel rate and carbon emission rate were decreased by 13.4, 22.1 and 19.25 kg ~ t-1 , respectively. The ratio of ore to coke, solid burden charging rate and hot metal productivity were increased by 4. 790%, 7.55 kg · s^- 1 and 6.38%, respectively. Heat taken away by top gas and energy consumption per ton hot metal were increased by 68.97% and 6.40%, respectively. Generally speaking, hot burden charging was ad verse to energy utilization of blast furnace.展开更多
Frequency and scale of the blasting events are increasing to boost limestone production. Mines areapproaching close to inhabited areas due to growing population and limited availability of land resourceswhich has chal...Frequency and scale of the blasting events are increasing to boost limestone production. Mines areapproaching close to inhabited areas due to growing population and limited availability of land resourceswhich has challenged the management to go for safe blasts with special reference to opencast mining.The study aims to predict the distance covered by the flyrock induced by blasting using artificial neuralnetwork （ANN） and multi-variate regression analysis （MVRA） for better assessment. Blast design andgeotechnical parameters, such as linear charge concentration, burden, stemming length, specific charge,unconfined compressive strength （UCS）, and rock quality designation （RQD）, have been selected as inputparameters and flyrock distance used as output parameter. ANN has been trained using 95 datasets ofexperimental blasts conducted in 4 opencast limestone mines in India. Thirty datasets have been used fortesting and validation of trained neural network. Flyrock distances have been predicted by ANN, MVRA,as well as further calculated using motion analysis of flyrock projectiles and compared with the observeddata. Back propagation neural network （BPNN） has been proven to be a superior predictive tool whencompared with MVRA. 2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.展开更多
The temperature distribution of COREX melter gasifier was studied by using a two-dimensional 1/30 scale thermal dynamic model.A set of operating conditions,such as radial distribution of direct reduction iron（DRI） t...The temperature distribution of COREX melter gasifier was studied by using a two-dimensional 1/30 scale thermal dynamic model.A set of operating conditions,such as radial distribution of direct reduction iron（DRI） to lump coal and coke volume ratio,coke charging location,coke charging amount and coke size,were taken into account.The results show that the temperature near the wall region decreases with the decrease of the radial distribution of DRI to lump coal and coke volume ratio.The temperature with central coke charging is higher than that without central coke column.Furthermore,the temperature significantly increases with the increase of central coke charging amount.With the increase of intermediate coke charging amount,the temperature near the wall region decreases while the temperature in the intermediate region increases.The temperature increases with the increase of coke size whether charging central coke or intermediate coke.展开更多
基金Item Sponsored by National Natural Science Foundation of China(50804008)Program for New Century Excellent Talents in University of China(NCET-08-0099)
文摘Blast furnace operation with hot burden charging was numerically simulated to preliminarily analyze its advantages and disadvantages. Multi-fluid blast furnace model was utilized to simulate hot burden charging operations under the conditions that the charging temperatures of pellet and coke were supposed separately or simultaneously as 800℃. The results showed that, with hot burden charging, the furnace top temperature significantly increased in comparison to the conventional operation with cold hurden charging. However, in-furnace temperature decreased, which decelerated the reduction rate of ferrous burdens. The concentrations of reducing gases were decreased in the furnace. The height of cohesive zone shifted downwards. When the charging temperatures of pellet and coke were simultaneously 800 ~C （PC800）, coke rate, fuel rate and carbon emission rate were decreased by 13.4, 22.1 and 19.25 kg ~ t-1 , respectively. The ratio of ore to coke, solid burden charging rate and hot metal productivity were increased by 4. 790%, 7.55 kg · s^- 1 and 6.38%, respectively. Heat taken away by top gas and energy consumption per ton hot metal were increased by 68.97% and 6.40%, respectively. Generally speaking, hot burden charging was ad verse to energy utilization of blast furnace.
文摘Frequency and scale of the blasting events are increasing to boost limestone production. Mines areapproaching close to inhabited areas due to growing population and limited availability of land resourceswhich has challenged the management to go for safe blasts with special reference to opencast mining.The study aims to predict the distance covered by the flyrock induced by blasting using artificial neuralnetwork （ANN） and multi-variate regression analysis （MVRA） for better assessment. Blast design andgeotechnical parameters, such as linear charge concentration, burden, stemming length, specific charge,unconfined compressive strength （UCS）, and rock quality designation （RQD）, have been selected as inputparameters and flyrock distance used as output parameter. ANN has been trained using 95 datasets ofexperimental blasts conducted in 4 opencast limestone mines in India. Thirty datasets have been used fortesting and validation of trained neural network. Flyrock distances have been predicted by ANN, MVRA,as well as further calculated using motion analysis of flyrock projectiles and compared with the observeddata. Back propagation neural network （BPNN） has been proven to be a superior predictive tool whencompared with MVRA. 2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.
基金Item Sponsored by Fundamental Research Funds for Central Universities of China(090402021)
文摘The temperature distribution of COREX melter gasifier was studied by using a two-dimensional 1/30 scale thermal dynamic model.A set of operating conditions,such as radial distribution of direct reduction iron（DRI） to lump coal and coke volume ratio,coke charging location,coke charging amount and coke size,were taken into account.The results show that the temperature near the wall region decreases with the decrease of the radial distribution of DRI to lump coal and coke volume ratio.The temperature with central coke charging is higher than that without central coke column.Furthermore,the temperature significantly increases with the increase of central coke charging amount.With the increase of intermediate coke charging amount,the temperature near the wall region decreases while the temperature in the intermediate region increases.The temperature increases with the increase of coke size whether charging central coke or intermediate coke.
