In this work,the effects of injecting an evaporating liquid jet into solid–gas flow are experimentally investigated.A new model(SHED model) and a supplementary model(spray model) have also been proposed to investigat...In this work,the effects of injecting an evaporating liquid jet into solid–gas flow are experimentally investigated.A new model(SHED model) and a supplementary model(spray model) have also been proposed to investigate some flow-field characteristics in three-phase fluidized bed with the mean relative error 4.3% between model and measured results.Some experiments were conducted to study the influences of flow-field parameters such as liquid volumetric flow rate,injection velocity,jet angle and gas superficial velocity as well as solid mass flux on the jet penetration depth(JPD).In addition,independent variables were experimentally employed to propose two empirical correlations for JPD by using multiple regression method and spray cone angle(SCA) by using dimensional analysis technique.The mean relative errors between the JPD and SCA correlations versus experimental data were 7.5% and 3.9%,respectively.In addition,in order to identify the variable effect,a parametric study was carried out.Applying the proposed model can avoid direct use of expensive devices to measure JPD and to predict droplet size.展开更多
To investigate the gas-solid flow pattern of a combustor-style fluid catalytic cracking regenerator, a laboratory-scale regenerator was designed. In scaling down from an actual regenerator, large-diameter hydrodynamic...To investigate the gas-solid flow pattern of a combustor-style fluid catalytic cracking regenerator, a laboratory-scale regenerator was designed. In scaling down from an actual regenerator, large-diameter hydrodynamic effects were taken into consideration. These considerations are the novelties of the present study. Applying the Eulerian-Eulerian approach, a three-dimensional computational fluid dynamics （CFD） model of the regenerator was developed. Using this model, various aspects of the hydrodynamic behavior that are potentially effective in catalyst regeneration were investigated. The CFD simulation results show that at various sections the gas-solid flow patterns exhibit different behavior because of the asymmetric location of the catalyst inlets and the lift outlets. The ratio of the recirculated catalyst to spent catalyst determines the quality of the spent and recirculated catalyst mixing and distribution because the location and quality of vortices change in the lower part of the combustor. The simulation results show that recirculated catalyst considerably reduces the air bypass that disperses the catalyst particles widely over the cross section. Decreasing the velocity of superficial air produces a complex flow pattern whereas the variation in catalyst mass flux does not alter the flow pattern significantly as the flow is dilute.展开更多
文摘In this work,the effects of injecting an evaporating liquid jet into solid–gas flow are experimentally investigated.A new model(SHED model) and a supplementary model(spray model) have also been proposed to investigate some flow-field characteristics in three-phase fluidized bed with the mean relative error 4.3% between model and measured results.Some experiments were conducted to study the influences of flow-field parameters such as liquid volumetric flow rate,injection velocity,jet angle and gas superficial velocity as well as solid mass flux on the jet penetration depth(JPD).In addition,independent variables were experimentally employed to propose two empirical correlations for JPD by using multiple regression method and spray cone angle(SCA) by using dimensional analysis technique.The mean relative errors between the JPD and SCA correlations versus experimental data were 7.5% and 3.9%,respectively.In addition,in order to identify the variable effect,a parametric study was carried out.Applying the proposed model can avoid direct use of expensive devices to measure JPD and to predict droplet size.
文摘To investigate the gas-solid flow pattern of a combustor-style fluid catalytic cracking regenerator, a laboratory-scale regenerator was designed. In scaling down from an actual regenerator, large-diameter hydrodynamic effects were taken into consideration. These considerations are the novelties of the present study. Applying the Eulerian-Eulerian approach, a three-dimensional computational fluid dynamics （CFD） model of the regenerator was developed. Using this model, various aspects of the hydrodynamic behavior that are potentially effective in catalyst regeneration were investigated. The CFD simulation results show that at various sections the gas-solid flow patterns exhibit different behavior because of the asymmetric location of the catalyst inlets and the lift outlets. The ratio of the recirculated catalyst to spent catalyst determines the quality of the spent and recirculated catalyst mixing and distribution because the location and quality of vortices change in the lower part of the combustor. The simulation results show that recirculated catalyst considerably reduces the air bypass that disperses the catalyst particles widely over the cross section. Decreasing the velocity of superficial air produces a complex flow pattern whereas the variation in catalyst mass flux does not alter the flow pattern significantly as the flow is dilute.
