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PERFORMANCE EVALUATION OF submergence ratio OF A RECTANGULAR SUBMERGED VANE WITH A COLLAR

International Journal of Sediment Research 2006年第1期21卷 42-49页

作者： Umesh P. GUPTA Nayan SHARMA C. S. P. OJHA Morphology Directorate Central Water Commission New Delhi (India) Dr. WRDTC Indian Institute of Technology Roorkee (India) Prof. Indian Institute of Technology Roorkee (India)Prof. Civil Engg. Dept.

The vane induced strength of secondary flow in terms of dimensionless moment of momentum is maximum in the case of a rectangular vane with a collar at angle of attack 400 at different degrees of submergence (T/d) such as 0.60, 0.67 and 0.75. The same value of optimal angle of attack was found by Marelius and Sinha (1998) in the case of a rectangular vane without a collar. The vane induced strength of a vortex is insensitive to the submergence ratio (T/d). The vane induced strength of a vortex in terms of moment of momentum (MOM) depends on a wide range of variables, such as angle of attack, vane height, vane length, vane thickness flow depth, water density, median sediment size, velocity vector, acceleration due to gravity, water dynamic viscosity, vane shape, taper angle, etc. The optimal angle of attack is very close to 400. A dimensionless moment of momentum parameter has also been identified. Vane induced secondary flow is also related to linear momentum. The graphical plot of moment of momentum vs. different angle of attack shows a similar trend as that of the plot of dimensionless MOM such as MOM made non- dimensional by flow depth or by vane height vs. angle of attack.

关键词： Vane Secondary flow Moment of momentum Optimal angle of attack submergence ratio Dimensionless moment of momentum Linear Momentum

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Performance characteristics of the airlift pump under vertical solid-water-gas flow conditions for conveying centimetric-sized coal particles

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International Journal of Coal Science & Technology 2024年第2期11卷 53-66页

作者： Parviz Enany Carsten Drebenshtedt Faculty of Mining and Special Civil Engineering Technische Universitat BergakademieGustav-Zeuner StraBe 1A09599FreibergGermany

In this study,the installation of an airlift pump with inner diameter of 102 mm and length of 5.64 m was utilized to consider the conveying process of non-spherical coal particles with density of 1340 kg/m3 and graining 25-44.5 *** test results revealed that the magnitude of increase in the solid transport rate due to the changes in the three tested parameters between compressed air velocity,submergence ratio,and feeding coal possibility was not the same,which are stand in range of 20%,75%,and 40%,***,creating the optimal airlift pump performance is highly dependent on submergence *** importantly,we measured the solid volume fraction using the method of one-way valves in order to minimize the disadvantages of conventional devices,such as fast speed camera and conductivity ring *** results confirmed that the volume fraction of the solid phase in the transfer process was always less than 12%.To validate present experimental data,the existing empirical correlations together with the theoretical equations related to the multiphase flow was *** overall agreement between the theory and experimental solid delivery results was particularly good instead of the first stage of conveying *** drawback can be corrected by omitting the role of friction and shear stress at low air income *** was also found that the model developed by Kalenik failed to predict the performance of our airlift operation in terms of the mass flow rate of the coal particles.

关键词： Vertical velocity Non-spherical particle submergence ratio Three-phase flow Churn flow Superficial velocity

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Evaluation of airlift pump performance for vertical conveying of coal particles

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International Journal of Coal Science & Technology 2023年第3期10卷 155-166页

作者： Parviz Enany Oleksandr Shevchenko Carsten Drebenshtedt Faculty of Mining and Special Civil Engineering Technische Universitat BergakademieGustav-Zeuner StraBe 1A09599 FreibergGermany UTF GmbH ErzstraBe 1509618 Brand-ErbisdorfGermany

One of the crucial aspects of reducing air consumption when conveying particles with an airlift pump is to know the factors that affect the process of particle motion at an initial velocity of *** determine the influence of submer-gence ratio and physical properties of particles(such as size,shape,and mass)on the onset of vertical particle motion,the airlift pump was taken as the research object,and spherical glass together with irregular shaped coal were used as experimental test *** results show that unlike the water-solid environment,the start of particle motion in the water-air mixture does not always occur at a certain value of superficial water velocity and this value also increases with increasing submergence *** the parameters considered,the role of submergence ratio is much more effective than the dimensions and the shape of the particle,because by increasing submergence from 0.3 to 0.8,it is possible to reduce air consumption by up to 8 *** on this study the corresponding theoretical model derived by Fujimoto et *** optimized,wherein the overall agreement between the modified theory and present experimental data is particularly *** to Fujimoto,the minimum superficial water velocity for lifting solids in the air-water mixture is not always smaller than water ambient which indicates on optimum submergence ratio higher than ***,a new criterion was introduced to describe the moment of onset of the particle motion as a function of the superficial fluid velocity ratio for each submergence value.

关键词： Air-water-solid flow Slurry- Coal submergence ratio Taylor bubble Superficial velocity

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Effect of Air Injector on the Performance of an Air-lift for Conveying River Sand

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Chinese Journal of Mechanical Engineering 2010年第1期23卷 122-128页

作者： TANG Chuanlin HU Dong PEI Jianghong YANG Lin College of Mechanical Engineering Hunan University of Technology Zhuzhou 412008 China Department of Mechanical Engineering Chongqing Jiaotong University Chongqing 400044 China

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.

关键词： air-lift submergence ratio air flow rate air injector lifting efficiency

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