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 multi-tube air-lift loop reactor (MT-ALR) is presented in this paper. Based on the energy conservation, a mathematical model describing the liquid circulation flow rate was developed, which was determined by gas vel...A multi-tube air-lift loop reactor (MT-ALR) is presented in this paper. Based on the energy conservation, a mathematical model describing the liquid circulation flow rate was developed, which was determined by gas velocity, the cross areas of riser and downcomer, gas hold-up and the local frictional loss coefficient. The experimental data indicate that either increase of gas flow rate or reduction of the downcomer diameter contributes to higher liquid circulation rate. The correlation between total and the local frictional loss coefficients was also established.Effects of gas flowrate in two risers and diameter of downcomer on the liquid circulation rate were examined. The value of total frictional loss coefficient was measured as a function of the cross area of downcomer and independent of the gas flow rate. The calculated results of liquid circulation rates agreed well with the experimental data with an average relative error of 9.6%.展开更多
The present study is concerned with the lifting of seabed materials by a BJT （bubble-jet-type） air-lift pump patented by Sadatomi. The targets are methane-hydrate rich muds on the bed about 200 m in depth around Jap...The present study is concerned with the lifting of seabed materials by a BJT （bubble-jet-type） air-lift pump patented by Sadatomi. The targets are methane-hydrate rich muds on the bed about 200 m in depth around Japan islands and rare-earth rich muds on the bed deeper than 4,000 m around Minami-Torishima islands in the Pacific Ocean. Feasibility studies were conducted using 50 mm I. D. （inner diameter） and 5.0 m long vertical pipe as the pump upriser, VC （vinyl chloride） particles and natural sands mixture in the methane-hydrate case, and ceramics particles with 3,761 kg/m^3 in density in the rare-earth case as the deposits. From the methane-hydrate simulation experiments, an efficient operation condition with high VC particles to sands lifting ratio has been clarified. In the rare-earth case, the air supplies from two different midways in the upriser pipe have been tested together with the bottom supply because the air supply from the upriser bottom is very hard in deep sea. The effects of the air supply position on the pump performance have been clarified by the experiments and the simulations with a revised model applicable to the midway air supply type.展开更多
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.
基金Supported by Liaoning Provincial Natural Science Foundation(No.972050).
文摘A multi-tube air-lift loop reactor (MT-ALR) is presented in this paper. Based on the energy conservation, a mathematical model describing the liquid circulation flow rate was developed, which was determined by gas velocity, the cross areas of riser and downcomer, gas hold-up and the local frictional loss coefficient. The experimental data indicate that either increase of gas flow rate or reduction of the downcomer diameter contributes to higher liquid circulation rate. The correlation between total and the local frictional loss coefficients was also established.Effects of gas flowrate in two risers and diameter of downcomer on the liquid circulation rate were examined. The value of total frictional loss coefficient was measured as a function of the cross area of downcomer and independent of the gas flow rate. The calculated results of liquid circulation rates agreed well with the experimental data with an average relative error of 9.6%.
文摘The present study is concerned with the lifting of seabed materials by a BJT （bubble-jet-type） air-lift pump patented by Sadatomi. The targets are methane-hydrate rich muds on the bed about 200 m in depth around Japan islands and rare-earth rich muds on the bed deeper than 4,000 m around Minami-Torishima islands in the Pacific Ocean. Feasibility studies were conducted using 50 mm I. D. （inner diameter） and 5.0 m long vertical pipe as the pump upriser, VC （vinyl chloride） particles and natural sands mixture in the methane-hydrate case, and ceramics particles with 3,761 kg/m^3 in density in the rare-earth case as the deposits. From the methane-hydrate simulation experiments, an efficient operation condition with high VC particles to sands lifting ratio has been clarified. In the rare-earth case, the air supplies from two different midways in the upriser pipe have been tested together with the bottom supply because the air supply from the upriser bottom is very hard in deep sea. The effects of the air supply position on the pump performance have been clarified by the experiments and the simulations with a revised model applicable to the midway air supply type.
