It has long been recognized that the flow pattern,especially the velocity distribution of the fluid,is of great importance in determining the performance of the equipment using structured packing as its internals.By u...It has long been recognized that the flow pattern,especially the velocity distribution of the fluid,is of great importance in determining the performance of the equipment using structured packing as its internals.By using three-dimensional laser Doppler velocimetry(LDV),the liquid velocity distribution of the glycerol aqueous solution was measured in a typical unit of structured packing(Mellapak 350Y).Time averaged three-dimensional velocity distributions of the unit were measured at different flow rates.The experimental data showed that the liquid velocity profile of the single phase flow was complex because of the special geometry of the unit of structured packing.In the central region of the unit,the liquid was mixed strongly and re-distributed.It was the main cause generating the vortexes and secondary flow.展开更多
The velocity, phase fraction and fluctuation velocity of dense clusters are obtained by analysis of transient velocity signals from laser Doppler velocimeter The local velocity of dense clusters increased linearly wit...The velocity, phase fraction and fluctuation velocity of dense clusters are obtained by analysis of transient velocity signals from laser Doppler velocimeter The local velocity of dense clusters increased linearly with superficial gas velocity, while the cross sectional average solids fraction influence the velocity of dense clusters insignificantly A Boltzmann function is used to describe the velocity radial distribution of dense clusters The radial distribution of the phase fraction for dense clusters is described by using an exponential function With the increase of cross sectional average solids fraction, the local phase fraction of dense clusters increases and the area controlled by dense clusters is enlarged The turbulence intensity of dense clusters is highest in the center of the bed while decreases towards the展开更多
文摘It has long been recognized that the flow pattern,especially the velocity distribution of the fluid,is of great importance in determining the performance of the equipment using structured packing as its internals.By using three-dimensional laser Doppler velocimetry(LDV),the liquid velocity distribution of the glycerol aqueous solution was measured in a typical unit of structured packing(Mellapak 350Y).Time averaged three-dimensional velocity distributions of the unit were measured at different flow rates.The experimental data showed that the liquid velocity profile of the single phase flow was complex because of the special geometry of the unit of structured packing.In the central region of the unit,the liquid was mixed strongly and re-distributed.It was the main cause generating the vortexes and secondary flow.
文摘The velocity, phase fraction and fluctuation velocity of dense clusters are obtained by analysis of transient velocity signals from laser Doppler velocimeter The local velocity of dense clusters increased linearly with superficial gas velocity, while the cross sectional average solids fraction influence the velocity of dense clusters insignificantly A Boltzmann function is used to describe the velocity radial distribution of dense clusters The radial distribution of the phase fraction for dense clusters is described by using an exponential function With the increase of cross sectional average solids fraction, the local phase fraction of dense clusters increases and the area controlled by dense clusters is enlarged The turbulence intensity of dense clusters is highest in the center of the bed while decreases towards the
