Local phase holdups in an inverse three-phase turbulent bed of 150 mm i.d. and 4350 mm height were measured simultaneously by micro-electrical conductivity probe technique in this study.The experiments were carried ou...Local phase holdups in an inverse three-phase turbulent bed of 150 mm i.d. and 4350 mm height were measured simultaneously by micro-electrical conductivity probe technique in this study.The experiments were carried out with polyethylene particles （dp=4.01 mm, ρs=926 kg·m -3）,air, and water[0.05%（mass）SCMC, 0.20%（mass）SCMC] as solid phase,gas phase and liquid phase respectively.540 sets of experimental data of local phase holdups in radial direction were obtained under Ug=U g3. It was found that the distribution of local solid holdup showed a maximum peak at r/R=（0.75—0.90）. The range of maximum peaks was larger than that of conventional fluidized beds. The distribution of local gas holdup in radial direction showed a maximum value at the column center and a minimum value near the wall.Moreover,the non-homogeneous distribution of local gas holdup in radial directions was more evident than that of conventional fluidized beds.The different operation regimes as well as the corresponding three specific gas velocities （U g1 ,U g2 and U g3） were obtained on the basis of the axial distribution characteristics of cross-sectional average solid holdups.The effect of the operating conditions （liquid viscosity, initial volume fraction of solids H s0/H0, initial liquid height H l0 ） on the specific gas velocities was presented.展开更多
At present, the method of calculating the turbulent flow width around the bridge pier is not given in the ＂Standard for Inland River Navigation＂ （GB50139-2004） in China, and the bridge designer usually increases t...At present, the method of calculating the turbulent flow width around the bridge pier is not given in the ＂Standard for Inland River Navigation＂ （GB50139-2004） in China, and the bridge designer usually increases the bridge span in order to ensure the navigation safety, which increases both of the structural design difficulty and the project investments. Therefore, it is extremely essential to give a research on the turbulent flow width around the bridge pier. Through the experiments of the fixed bed and the mobile bed, the factors influencing the turbulent flow width around the bridge pier have been analyzed, such as the approaching flow speed, the water depth, the angles between the bridge pier and the flow direction, the sizes of bridge pier, the shapes of the bridge pier, and the scouting around the bridge pier, etc. Through applying the dimension analytic method to the measured data, the formula of calculating the turbulent flow width around the bridge pier is then inferred.展开更多
文摘Local phase holdups in an inverse three-phase turbulent bed of 150 mm i.d. and 4350 mm height were measured simultaneously by micro-electrical conductivity probe technique in this study.The experiments were carried out with polyethylene particles （dp=4.01 mm, ρs=926 kg·m -3）,air, and water[0.05%（mass）SCMC, 0.20%（mass）SCMC] as solid phase,gas phase and liquid phase respectively.540 sets of experimental data of local phase holdups in radial direction were obtained under Ug=U g3. It was found that the distribution of local solid holdup showed a maximum peak at r/R=（0.75—0.90）. The range of maximum peaks was larger than that of conventional fluidized beds. The distribution of local gas holdup in radial direction showed a maximum value at the column center and a minimum value near the wall.Moreover,the non-homogeneous distribution of local gas holdup in radial directions was more evident than that of conventional fluidized beds.The different operation regimes as well as the corresponding three specific gas velocities （U g1 ,U g2 and U g3） were obtained on the basis of the axial distribution characteristics of cross-sectional average solid holdups.The effect of the operating conditions （liquid viscosity, initial volume fraction of solids H s0/H0, initial liquid height H l0 ） on the specific gas velocities was presented.
基金Supported by the West Waterway Transportation Construction Foundation under Grant No.2004-328-000-40.
文摘At present, the method of calculating the turbulent flow width around the bridge pier is not given in the ＂Standard for Inland River Navigation＂ （GB50139-2004） in China, and the bridge designer usually increases the bridge span in order to ensure the navigation safety, which increases both of the structural design difficulty and the project investments. Therefore, it is extremely essential to give a research on the turbulent flow width around the bridge pier. Through the experiments of the fixed bed and the mobile bed, the factors influencing the turbulent flow width around the bridge pier have been analyzed, such as the approaching flow speed, the water depth, the angles between the bridge pier and the flow direction, the sizes of bridge pier, the shapes of the bridge pier, and the scouting around the bridge pier, etc. Through applying the dimension analytic method to the measured data, the formula of calculating the turbulent flow width around the bridge pier is then inferred.
