Rotational feeding combined with shift feeding electrochemical trepanning(RF-SF ECTr)is an effective method for machining aeroengine blisks.However,given the variable relative motion of the electrodes and the complex ...Rotational feeding combined with shift feeding electrochemical trepanning(RF-SF ECTr)is an effective method for machining aeroengine blisks.However,given the variable relative motion of the electrodes and the complex flow channels around the bending and twisting blades,the accessibility and uniformity of the flow field are poor in blisk RF-SF ECTr using the traditional electrolyte supply(TES)mode,resulting in poor machining stability and low machining efficiency.To improve the distribution of the flow field,a new multi-channel electrolyte supply(MCES)mode is proposed for blisk RF-SF ECTr,in which the position and volume of the electrolyte supply are controlled effectively by setting multiple inlet channels in the liquid inlet area.A flow-field simulation comparison between TES and MCES shows that better accessibility and uniformity of the flow-field distribution are achieved under MCES.To clarify further the flow-field distribution characteristics under RF-SF ECTr,a series of flow-field simulations was conducted at different machining depths.Based on the obtained dynamic change law for the flow field,to enhance further its uniformity and accessibility,a global coverage strategy for the electrolyte supply and a flow-field structure optimization method for MCES are proposed,which involve optimizing the number,diameter,and location of the inlet channels.After many simulations,the optimal MCES structure was achieved whereby the electrolyte covers all positions effectively in the processing area.To verify the proposed method as effective and correct,a series of RF-SF ECTr experiments was carried out.Under the optimized MCES mode,the feeding rate was increased from 0.8 mm/min with the TES mode to 2.0 mm/min,and the processing stability and efficiency were improved significantly.The methods presented here offer an effective guide for flow-field optimization when machining other components with complex spatial structures.展开更多
This paper presents experimental results from physical and mathematical simulation of liquid steel flow in the tundish adopting gas bubbling curtain substituting dam and industrial trials have been investigated based ...This paper presents experimental results from physical and mathematical simulation of liquid steel flow in the tundish adopting gas bubbling curtain substituting dam and industrial trials have been investigated based the experimental results. Physical and mathematical simulation results show the gas bubbling curtain can improve pattern of liquid flow in the tundish , accelerate inclusions flotation,and simultaneity metallurgy effect has been further improved when combining weir and turbulence inhibitor. The industrial trial results confirm that content of oxygen , nitrogen and inclusions in continuous casting billets have been reduced when gas bubbling curtain combining weir and turbulence inhibitor.展开更多
Aiming at the problems of high heat and large temperature difference in the sub flow of tundish in the two flow channel type induction heating steelmaking plant of Delong iron and Steel Co., Ltd., the effects of diffe...Aiming at the problems of high heat and large temperature difference in the sub flow of tundish in the two flow channel type induction heating steelmaking plant of Delong iron and Steel Co., Ltd., the effects of different flow channels on the flow field and temperature field of tundish were simulated and optimized. This paper analyzes the influencing factors of ladle heat preservation technology, and puts forward the optimal structure of split flow channel with variable diameter. After the optimization, the temperature difference between each flow of the intermediate ladle is only 1-2 ℃, which not only ensures the heat preservation effect of the molten steel in the ladle, but also realizes the uniformity of the molten steel between each flow. At the same time, the transformation control of the ladle is conducive to the floating removal of inclusions and improves the quality of the ladle. The smelting effect of tundish in steelmaking plant is analyzed.展开更多
A vortex electrostatic precipitator （VEP） forms a vortex flow field within a precipitator by means of the vertical staggered layout of the double-vortex collecting plate facing the direction of the gas flow. The ion...A vortex electrostatic precipitator （VEP） forms a vortex flow field within a precipitator by means of the vertical staggered layout of the double-vortex collecting plate facing the direction of the gas flow. The ion concentrations within the precipitator can be significantly increased. Correspondingly, the charging and coagulation rates of fine particles and particle migration velocity are significantly improved within the VEP. Since it can effectively collect fine particles and reduce precipitator size, VEPs represent a new type of electrostatic precipitator with great application potential. In this work the change curve of the external voltage, gas velocity, row spacing and effective collecting area influencing the precipitation efficiency were acquired through a single-factor experiment. Using an orthogonal regression design, attempts were made to analyze the major operating parameters influencing the collecting efficiency of fine particles, establish a multiple linear regression model and analyze the weights of factors and then acquire quantitative rules relating experimental indicators and factors. The regression model was optimized by MATLAB programming, and we then obtained the optimal factor combination which can enhance the efficiency of fine particle collection. The final optimized result is that： when gas velocity is 3.4 m s-1, the external voltage is 18 kV, row spacing is 100 mm and the effective collecting area is 1.13 m2, the rate of fine particle collection is 89.8867%. After determining and analyzing the state of the internal flow field within the VEP by particle image velocimetry （PIV）, the results show that, for a particular gas velocity, a vortex zone and laminar zone are distinctly formed within the VEP, which increases the ion transport ratio as well as the charging, coagulation and collection rates of fine particles within the precipitator, thus making further improvements in the efficiency of fine particle collection.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.52275435,52075465,52375519)Open Fund Project of Jiangsu Key Laboratory of Precision and Micro-manufacturing Technology(Grant No.JSKL2324K03)Key Research and Development Program of Hunan Province of China(Grant No.2023GK2026)。
文摘Rotational feeding combined with shift feeding electrochemical trepanning(RF-SF ECTr)is an effective method for machining aeroengine blisks.However,given the variable relative motion of the electrodes and the complex flow channels around the bending and twisting blades,the accessibility and uniformity of the flow field are poor in blisk RF-SF ECTr using the traditional electrolyte supply(TES)mode,resulting in poor machining stability and low machining efficiency.To improve the distribution of the flow field,a new multi-channel electrolyte supply(MCES)mode is proposed for blisk RF-SF ECTr,in which the position and volume of the electrolyte supply are controlled effectively by setting multiple inlet channels in the liquid inlet area.A flow-field simulation comparison between TES and MCES shows that better accessibility and uniformity of the flow-field distribution are achieved under MCES.To clarify further the flow-field distribution characteristics under RF-SF ECTr,a series of flow-field simulations was conducted at different machining depths.Based on the obtained dynamic change law for the flow field,to enhance further its uniformity and accessibility,a global coverage strategy for the electrolyte supply and a flow-field structure optimization method for MCES are proposed,which involve optimizing the number,diameter,and location of the inlet channels.After many simulations,the optimal MCES structure was achieved whereby the electrolyte covers all positions effectively in the processing area.To verify the proposed method as effective and correct,a series of RF-SF ECTr experiments was carried out.Under the optimized MCES mode,the feeding rate was increased from 0.8 mm/min with the TES mode to 2.0 mm/min,and the processing stability and efficiency were improved significantly.The methods presented here offer an effective guide for flow-field optimization when machining other components with complex spatial structures.
文摘This paper presents experimental results from physical and mathematical simulation of liquid steel flow in the tundish adopting gas bubbling curtain substituting dam and industrial trials have been investigated based the experimental results. Physical and mathematical simulation results show the gas bubbling curtain can improve pattern of liquid flow in the tundish , accelerate inclusions flotation,and simultaneity metallurgy effect has been further improved when combining weir and turbulence inhibitor. The industrial trial results confirm that content of oxygen , nitrogen and inclusions in continuous casting billets have been reduced when gas bubbling curtain combining weir and turbulence inhibitor.
文摘Aiming at the problems of high heat and large temperature difference in the sub flow of tundish in the two flow channel type induction heating steelmaking plant of Delong iron and Steel Co., Ltd., the effects of different flow channels on the flow field and temperature field of tundish were simulated and optimized. This paper analyzes the influencing factors of ladle heat preservation technology, and puts forward the optimal structure of split flow channel with variable diameter. After the optimization, the temperature difference between each flow of the intermediate ladle is only 1-2 ℃, which not only ensures the heat preservation effect of the molten steel in the ladle, but also realizes the uniformity of the molten steel between each flow. At the same time, the transformation control of the ladle is conducive to the floating removal of inclusions and improves the quality of the ladle. The smelting effect of tundish in steelmaking plant is analyzed.
基金sponsored by the National Natural Science Foundation of China(grant no.51278229)the Six Talent Peak Project of Jiangsu Province(grant no.JNHB-018)
文摘A vortex electrostatic precipitator （VEP） forms a vortex flow field within a precipitator by means of the vertical staggered layout of the double-vortex collecting plate facing the direction of the gas flow. The ion concentrations within the precipitator can be significantly increased. Correspondingly, the charging and coagulation rates of fine particles and particle migration velocity are significantly improved within the VEP. Since it can effectively collect fine particles and reduce precipitator size, VEPs represent a new type of electrostatic precipitator with great application potential. In this work the change curve of the external voltage, gas velocity, row spacing and effective collecting area influencing the precipitation efficiency were acquired through a single-factor experiment. Using an orthogonal regression design, attempts were made to analyze the major operating parameters influencing the collecting efficiency of fine particles, establish a multiple linear regression model and analyze the weights of factors and then acquire quantitative rules relating experimental indicators and factors. The regression model was optimized by MATLAB programming, and we then obtained the optimal factor combination which can enhance the efficiency of fine particle collection. The final optimized result is that： when gas velocity is 3.4 m s-1, the external voltage is 18 kV, row spacing is 100 mm and the effective collecting area is 1.13 m2, the rate of fine particle collection is 89.8867%. After determining and analyzing the state of the internal flow field within the VEP by particle image velocimetry （PIV）, the results show that, for a particular gas velocity, a vortex zone and laminar zone are distinctly formed within the VEP, which increases the ion transport ratio as well as the charging, coagulation and collection rates of fine particles within the precipitator, thus making further improvements in the efficiency of fine particle collection.
