Dissertation > Industrial Technology > Hydraulic Engineering > The basic science of water resources project > Hydraulics > Pipeline Flow Mechanics

Studies on Mechanism of Hydraulic Hoist of Coarse Particle in Vertical Pipe

Author LiPengCheng
Tutor ZhouJianJun;HanWenLiang
School Tsinghua University
Course Hydraulic Engineering
Keywords coarse particle vertical pipe hydraulic hoist
Type PhD thesis
Year 2007
Downloads 253
Quotes 4
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Hydraulic hoist of solid coarse particles in the vertical pipe is used in oil extraction, chemical engineering, ocean mining, coal mining and silt cleanup and so on. For the safety and efficiency of the pipe, the motion of coarse particles in hydraulic hoist should be studied. The velocity and concentration of particles and the resistance of the pipe are the main topics. As well as the relationship between these parameters and the operation condition is important.For investigations of the velocity and concentration of the natural coarse particle, the test pipe system and the CCD camera measurement were developed. By the image processing of particle video, in series matching and statistics of particle image, the velocity and concentration of particles were obtained. The experimental results are valuable for the research of hydraulic hoist of coarse particles. The influences of the hoist flow velocity, transportation concentration and particle density on the velocity and concentration of coarse particles were analyzed. The developed measurement is applicable in the particle-fluid flow.The two dimensional numerical model for the hydraulic hoist of coarse particles in the vertical pipe was improved on the discrete particle model. The model was improved in the inclusion of turbulent flow velocity, particle rotation, and two-way couple between particle and flow. For the more effective consideration of influences on coarse particles in the flow, there is a good agreement between the simulated velocity and concentration distribution of coarse particles and experimental results. The motion of manganese nodules in the hoist pipe for the deep sea mining was forecasted by the model. By the simulated results, the smaller nodules, the proper hoist flow velocity and the suitable transportation concentration will ensure the safety and efficiency of the hoist system.The recommendatory formulas of the critical hoist flow velocity and pipeline resistance were presented for the engineering by comparing the previous studies. Calculating with the holistic parameters of the two-phase flow, these formulas are convenient for the engineers. These formulas are also validated by the experimental results. The effects on the radial distribution of coarse particle concentration were studied by the two-fluid model. The radial concentration distribution was decided by the integrated diffusive effects of turbulent flow velocity, turbulent particle velocity, particle collisions and radial forces. The defective result of the radial concentration distribution of the coarse particles by the diffusion equation was analyzed. It will be better to forecast the concentration distribution by the numerical simulation.

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