A solution of 0.1 mol/L to 1.0 mol/L H2SO4 can dissolve alkali metals and alkaline earth metals which weaken an active site of SCR catalyst. The waste catalyst washed with 0.5 mol/L H2SO4 regained the best catalytic a...A solution of 0.1 mol/L to 1.0 mol/L H2SO4 can dissolve alkali metals and alkaline earth metals which weaken an active site of SCR catalyst. The waste catalyst washed with 0.5 mol/L H2SO4 regained the best catalytic activity. When a concentration of the sulfuric acid is less than 0.5 mol/L, sufficient cleaning effects cannot be obtained. In contrast, when the concentration is greater than 1.0 tool/L, the active components, vanadium and tungsten are undesirably eluted. The total BET surface of the catalyst regenerated by air lift loop reactor showed almost the same as that of fresh catalyst due to the removal of insoluble compounds which may be penetrated into pores of catalyst. The addition of a solution of 0.075 mol/L ammonium vanadate （NHnVO3） and 0.075 mol/L ammonium paratungstate （5（NH4）20· 12WO3-5H20） to 0.1 mol/L H2SO4 significantly increases the activity of the waste catalyst.展开更多
An air-lift has been more recently applied in the dredging, deep-seated beach placer mining and underground mining engineering. However, the influence and mechanism of various parameters on the air-lift performance ar...An air-lift has been more recently applied in the dredging, deep-seated beach placer mining and underground mining engineering. However, the influence and mechanism of various parameters on the air-lift performance are not quite clear, especially the influence of flow pattern on lifting efficiency. Focusing on the problems mentioned above, the key part of the air-lift （namely, the air injector） was proposed aimed to reduce friction loss in the inner pipe according to improving flow field performance, thus increase the lifting efficiency. The study of relative factors of the performance of an air-lift is performed and the river sand is used as simulation of underground ore bed. The total lifting height of the experimental system is 3 m, the water flux, mass flow of solid particles, concentration of particles and lifting efficiency are measured under the same submergence ratios by changing the air injector, which is divided into nine specifications of air injection in this research. The experimental results indicate that the optimal air flow rate corresponding to excellent performance of the air-lift can be obtained in the range of 35-40 m3/h. The air injection method has a great effect on the performance of the air-lift, the air injector with three nozzles is better than that in the case of one or two nozzles. Further more, the air injection angle and arrangement of air injection pipes also have great effect on the performance of an air-lift. The proposed research results have guiding significance for engineering application.展开更多
A fluid flow model consisting of Bernoulli’s law in its normal form, the equation of state of air, and the cross-stream force balance between a downward pressure gradient and the upward centrifugal force on fluid par...A fluid flow model consisting of Bernoulli’s law in its normal form, the equation of state of air, and the cross-stream force balance between a downward pressure gradient and the upward centrifugal force on fluid particles moving along curved streamlines over the top circular wing surface involving three equations in three unknowns (pressure, density and velocity) are solved to show that both density and pressure decrease upward as the inverse square of the distance from the circle’s center, and the velocity is independent of that dis-tance. These derived characteristics are used to explain the lift force on the wing in what is believed to be a novel way.展开更多
针对压缩空气储能(Compressed Air Energy Storage,CAES)电站地下人工洞室设计时计算洞室埋深未充分考虑围岩承载力的问题,参考国内外相关计算方法,基于极限平衡分析法提出一种CAES电站地下人工洞室埋深的计算方法,在考虑上覆岩体重力...针对压缩空气储能(Compressed Air Energy Storage,CAES)电站地下人工洞室设计时计算洞室埋深未充分考虑围岩承载力的问题,参考国内外相关计算方法,基于极限平衡分析法提出一种CAES电站地下人工洞室埋深的计算方法,在考虑上覆岩体重力作用、破坏面上抗剪力的情况下通过假定极限状态下的岩体破坏面建立极限平衡模型进行力学分析。同时,讨论破裂角、侧压力系数、埋深、洞径等参数对抗抬安全系数的影响。结果显示:破裂角对抗抬安全系数的影响规律与岩层侧压力系数相关,当侧压力系数一定时,抗抬安全系数随着破裂角的增大而增大;当破裂角一定时,抗抬安全系数随着侧压力系数的增大而增大。此外,抗抬安全系数随着洞室直径的增大而减小,随着洞室埋深的增大而增大。展开更多
基金Project(2009T100100602) supported by the Korea Institute of Energy Technology Evaluation and Planning,Korea
文摘A solution of 0.1 mol/L to 1.0 mol/L H2SO4 can dissolve alkali metals and alkaline earth metals which weaken an active site of SCR catalyst. The waste catalyst washed with 0.5 mol/L H2SO4 regained the best catalytic activity. When a concentration of the sulfuric acid is less than 0.5 mol/L, sufficient cleaning effects cannot be obtained. In contrast, when the concentration is greater than 1.0 tool/L, the active components, vanadium and tungsten are undesirably eluted. The total BET surface of the catalyst regenerated by air lift loop reactor showed almost the same as that of fresh catalyst due to the removal of insoluble compounds which may be penetrated into pores of catalyst. The addition of a solution of 0.075 mol/L ammonium vanadate （NHnVO3） and 0.075 mol/L ammonium paratungstate （5（NH4）20· 12WO3-5H20） to 0.1 mol/L H2SO4 significantly increases the activity of the waste catalyst.
基金supported by Ministry of Science and Technology of China (Grant No. 2008DFA70300)
文摘An air-lift has been more recently applied in the dredging, deep-seated beach placer mining and underground mining engineering. However, the influence and mechanism of various parameters on the air-lift performance are not quite clear, especially the influence of flow pattern on lifting efficiency. Focusing on the problems mentioned above, the key part of the air-lift （namely, the air injector） was proposed aimed to reduce friction loss in the inner pipe according to improving flow field performance, thus increase the lifting efficiency. The study of relative factors of the performance of an air-lift is performed and the river sand is used as simulation of underground ore bed. The total lifting height of the experimental system is 3 m, the water flux, mass flow of solid particles, concentration of particles and lifting efficiency are measured under the same submergence ratios by changing the air injector, which is divided into nine specifications of air injection in this research. The experimental results indicate that the optimal air flow rate corresponding to excellent performance of the air-lift can be obtained in the range of 35-40 m3/h. The air injection method has a great effect on the performance of the air-lift, the air injector with three nozzles is better than that in the case of one or two nozzles. Further more, the air injection angle and arrangement of air injection pipes also have great effect on the performance of an air-lift. The proposed research results have guiding significance for engineering application.
文摘A fluid flow model consisting of Bernoulli’s law in its normal form, the equation of state of air, and the cross-stream force balance between a downward pressure gradient and the upward centrifugal force on fluid particles moving along curved streamlines over the top circular wing surface involving three equations in three unknowns (pressure, density and velocity) are solved to show that both density and pressure decrease upward as the inverse square of the distance from the circle’s center, and the velocity is independent of that dis-tance. These derived characteristics are used to explain the lift force on the wing in what is believed to be a novel way.
文摘针对压缩空气储能(Compressed Air Energy Storage,CAES)电站地下人工洞室设计时计算洞室埋深未充分考虑围岩承载力的问题,参考国内外相关计算方法,基于极限平衡分析法提出一种CAES电站地下人工洞室埋深的计算方法,在考虑上覆岩体重力作用、破坏面上抗剪力的情况下通过假定极限状态下的岩体破坏面建立极限平衡模型进行力学分析。同时,讨论破裂角、侧压力系数、埋深、洞径等参数对抗抬安全系数的影响。结果显示:破裂角对抗抬安全系数的影响规律与岩层侧压力系数相关,当侧压力系数一定时,抗抬安全系数随着破裂角的增大而增大;当破裂角一定时,抗抬安全系数随着侧压力系数的增大而增大。此外,抗抬安全系数随着洞室直径的增大而减小,随着洞室埋深的增大而增大。
