The Experts below are selected from a list of 11511 Experts worldwide ranked by ideXlab platform
Rachel Smith - One of the best experts on this subject based on the ideXlab platform.
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a review of pulsed flow Fluidisation the effects of intermittent gas flow on fluidised gas solid bed behaviour
Powder Technology, 2016Co-Authors: Emma Ireland, Kate Pitt, Rachel SmithAbstract:Abstract Pulsed flow Fluidisation involves the use of either a relocating or intermittent gas stream flowing through a bed of particles, and produces a range of Fluidisation effects dependent on the type and frequency of the pulsation. Pulsed flow has been shown in a range of studies to improve mixing and heat transfer, and reduce agglomeration. However these effects are dependent on the pulsation frequency, particle characteristics and other process conditions. Research into pulsed flow fluidised beds has demonstrated a pattern for an improvement in heat and mass transfer rates, specifically in Group A and B particles, reduced slugging and channelling in wet or cohesive particles, and an improvement in the Fluidisation of hard to fluidise materials such as Group C powders. In addition, reduced energy consumption from lower minimum Fluidisation rates under pulsed flow further indicates a potentially significant efficiency improvement. These findings, however, highlight needs for correlations to be drawn between the effects studied and the pulsation method and frequencies applied. Here, we present a comparison of continuous and pulsed flow Fluidisation, and discuss effects such as minimum Fluidisation velocity, bubble characteristics and bed expansion. Areas for future research have been identified in order to build a better picture of how pulsed flow frequencies and particle characteristics interact, aiding the development of this technology within industry.
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A review of pulsed flow Fluidisation; the effects of intermittent gas flow on fluidised gas–solid bed behaviour
Powder Technology, 2016Co-Authors: Emma Ireland, Kate Pitt, Rachel SmithAbstract:Abstract Pulsed flow Fluidisation involves the use of either a relocating or intermittent gas stream flowing through a bed of particles, and produces a range of Fluidisation effects dependent on the type and frequency of the pulsation. Pulsed flow has been shown in a range of studies to improve mixing and heat transfer, and reduce agglomeration. However these effects are dependent on the pulsation frequency, particle characteristics and other process conditions. Research into pulsed flow fluidised beds has demonstrated a pattern for an improvement in heat and mass transfer rates, specifically in Group A and B particles, reduced slugging and channelling in wet or cohesive particles, and an improvement in the Fluidisation of hard to fluidise materials such as Group C powders. In addition, reduced energy consumption from lower minimum Fluidisation rates under pulsed flow further indicates a potentially significant efficiency improvement. These findings, however, highlight needs for correlations to be drawn between the effects studied and the pulsation method and frequencies applied. Here, we present a comparison of continuous and pulsed flow Fluidisation, and discuss effects such as minimum Fluidisation velocity, bubble characteristics and bed expansion. Areas for future research have been identified in order to build a better picture of how pulsed flow frequencies and particle characteristics interact, aiding the development of this technology within industry.
Emma Ireland - One of the best experts on this subject based on the ideXlab platform.
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a review of pulsed flow Fluidisation the effects of intermittent gas flow on fluidised gas solid bed behaviour
Powder Technology, 2016Co-Authors: Emma Ireland, Kate Pitt, Rachel SmithAbstract:Abstract Pulsed flow Fluidisation involves the use of either a relocating or intermittent gas stream flowing through a bed of particles, and produces a range of Fluidisation effects dependent on the type and frequency of the pulsation. Pulsed flow has been shown in a range of studies to improve mixing and heat transfer, and reduce agglomeration. However these effects are dependent on the pulsation frequency, particle characteristics and other process conditions. Research into pulsed flow fluidised beds has demonstrated a pattern for an improvement in heat and mass transfer rates, specifically in Group A and B particles, reduced slugging and channelling in wet or cohesive particles, and an improvement in the Fluidisation of hard to fluidise materials such as Group C powders. In addition, reduced energy consumption from lower minimum Fluidisation rates under pulsed flow further indicates a potentially significant efficiency improvement. These findings, however, highlight needs for correlations to be drawn between the effects studied and the pulsation method and frequencies applied. Here, we present a comparison of continuous and pulsed flow Fluidisation, and discuss effects such as minimum Fluidisation velocity, bubble characteristics and bed expansion. Areas for future research have been identified in order to build a better picture of how pulsed flow frequencies and particle characteristics interact, aiding the development of this technology within industry.
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A review of pulsed flow Fluidisation; the effects of intermittent gas flow on fluidised gas–solid bed behaviour
Powder Technology, 2016Co-Authors: Emma Ireland, Kate Pitt, Rachel SmithAbstract:Abstract Pulsed flow Fluidisation involves the use of either a relocating or intermittent gas stream flowing through a bed of particles, and produces a range of Fluidisation effects dependent on the type and frequency of the pulsation. Pulsed flow has been shown in a range of studies to improve mixing and heat transfer, and reduce agglomeration. However these effects are dependent on the pulsation frequency, particle characteristics and other process conditions. Research into pulsed flow fluidised beds has demonstrated a pattern for an improvement in heat and mass transfer rates, specifically in Group A and B particles, reduced slugging and channelling in wet or cohesive particles, and an improvement in the Fluidisation of hard to fluidise materials such as Group C powders. In addition, reduced energy consumption from lower minimum Fluidisation rates under pulsed flow further indicates a potentially significant efficiency improvement. These findings, however, highlight needs for correlations to be drawn between the effects studied and the pulsation method and frequencies applied. Here, we present a comparison of continuous and pulsed flow Fluidisation, and discuss effects such as minimum Fluidisation velocity, bubble characteristics and bed expansion. Areas for future research have been identified in order to build a better picture of how pulsed flow frequencies and particle characteristics interact, aiding the development of this technology within industry.
Subrat Das - One of the best experts on this subject based on the ideXlab platform.
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Analytical model to locate the Fluidisation interface in a solid–gas vacuum fluidised bed
Powder Technology, 2014Co-Authors: Apurv Kumar, Weimin Gao, Peter Hodgson, Daniel Fabijanic, Subrat DasAbstract:Abstract Vacuum fluidised beds have a distinct advantage of being operated with reduced mass consumption of the fluidising media. However, a low quality of Fluidisation reduces the opportunity to utilise the bubbling regime in vacuum fluidised beds. Fluidisation maps are often used to depict the interface between the quiescent, bubbling and slugging regimes inside a fluidised bed. Such maps have been obtained by visual observations of the Fluidisation interface in transparent fluidised beds. For beds which are visually inaccessible Fluidisation maps are difficult to obtain. The present work therefore attempts to model the interface travel in a vacuum fluidised bed. The pressure gradient due to the bed weight has been determined to be a main contributor for Fluidisation/deFluidisation under vacuum. A simple analytical model based on the pressure gradient (PG model) is developed to predict the interface location in a vacuum fluidised bed. For a segregated bed, the Gibilaro–Rowe (GR) model is modified and used to predict the jetsam layer growth along with the Fluidisation interface. The predictions are compared with the experimental data for minimally and highly segregated particles and it is seen that for non-segregated powders the predictions are quite accurate. Lack of sufficient knowledge of bubble characteristics, however, impeded accurate prediction of the jetsam growth especially at high flow rates. However, an approximate complete Fluidisation interface is successfully predicted using the GR–PG model.
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analytical model to locate the Fluidisation interface in a solid gas vacuum fluidised bed
Powder Technology, 2014Co-Authors: Apurv Kumar, Weimin Gao, Peter Hodgson, Daniel Fabijanic, Subrat DasAbstract:Abstract Vacuum fluidised beds have a distinct advantage of being operated with reduced mass consumption of the fluidising media. However, a low quality of Fluidisation reduces the opportunity to utilise the bubbling regime in vacuum fluidised beds. Fluidisation maps are often used to depict the interface between the quiescent, bubbling and slugging regimes inside a fluidised bed. Such maps have been obtained by visual observations of the Fluidisation interface in transparent fluidised beds. For beds which are visually inaccessible Fluidisation maps are difficult to obtain. The present work therefore attempts to model the interface travel in a vacuum fluidised bed. The pressure gradient due to the bed weight has been determined to be a main contributor for Fluidisation/deFluidisation under vacuum. A simple analytical model based on the pressure gradient (PG model) is developed to predict the interface location in a vacuum fluidised bed. For a segregated bed, the Gibilaro–Rowe (GR) model is modified and used to predict the jetsam layer growth along with the Fluidisation interface. The predictions are compared with the experimental data for minimally and highly segregated particles and it is seen that for non-segregated powders the predictions are quite accurate. Lack of sufficient knowledge of bubble characteristics, however, impeded accurate prediction of the jetsam growth especially at high flow rates. However, an approximate complete Fluidisation interface is successfully predicted using the GR–PG model.
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Investigating the effect of segregation of particles and pressure gradient on the quality of Fluidisation at sub-atmospheric pressures
Powder Technology, 2014Co-Authors: Apurv Kumar, Weimin Gao, Peter Hodgson, Subrat Das, Daniel FabijanicAbstract:Abstract Degradation in quality of Fluidisation for Group B powders under vacuum conditions occurs due to an existence of a Fluidisation interface that separates the bubbling and static bed near the minimum Fluidisation conditions. The significant pressure gradient existing due to bed weight and the particle segregation mainly affects the quality. The aim of the present work is to investigate the relative contribution of the pressure gradient and the presence of the segregation on the quality of Fluidisation in vacuum conditions. Further, the effect of morphology of the particles on Fluidisation quality is also studied. In addition, Fluidisation maps are also obtained that reveal the optimal area of operation for enhanced heat and mass transfer processes. The results indicate that the travel of interface in the bed is affected only when the level of segregation in the bed is high. For intermediate and minimal disparity in size, the quality degradation is caused by the presence of sharp pressure gradient. Changing the morphology of the particle also altered the Fluidisation characteristics of the bed and improved the quality significantly.
Daniel Fabijanic - One of the best experts on this subject based on the ideXlab platform.
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Analytical model to locate the Fluidisation interface in a solid–gas vacuum fluidised bed
Powder Technology, 2014Co-Authors: Apurv Kumar, Weimin Gao, Peter Hodgson, Daniel Fabijanic, Subrat DasAbstract:Abstract Vacuum fluidised beds have a distinct advantage of being operated with reduced mass consumption of the fluidising media. However, a low quality of Fluidisation reduces the opportunity to utilise the bubbling regime in vacuum fluidised beds. Fluidisation maps are often used to depict the interface between the quiescent, bubbling and slugging regimes inside a fluidised bed. Such maps have been obtained by visual observations of the Fluidisation interface in transparent fluidised beds. For beds which are visually inaccessible Fluidisation maps are difficult to obtain. The present work therefore attempts to model the interface travel in a vacuum fluidised bed. The pressure gradient due to the bed weight has been determined to be a main contributor for Fluidisation/deFluidisation under vacuum. A simple analytical model based on the pressure gradient (PG model) is developed to predict the interface location in a vacuum fluidised bed. For a segregated bed, the Gibilaro–Rowe (GR) model is modified and used to predict the jetsam layer growth along with the Fluidisation interface. The predictions are compared with the experimental data for minimally and highly segregated particles and it is seen that for non-segregated powders the predictions are quite accurate. Lack of sufficient knowledge of bubble characteristics, however, impeded accurate prediction of the jetsam growth especially at high flow rates. However, an approximate complete Fluidisation interface is successfully predicted using the GR–PG model.
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analytical model to locate the Fluidisation interface in a solid gas vacuum fluidised bed
Powder Technology, 2014Co-Authors: Apurv Kumar, Weimin Gao, Peter Hodgson, Daniel Fabijanic, Subrat DasAbstract:Abstract Vacuum fluidised beds have a distinct advantage of being operated with reduced mass consumption of the fluidising media. However, a low quality of Fluidisation reduces the opportunity to utilise the bubbling regime in vacuum fluidised beds. Fluidisation maps are often used to depict the interface between the quiescent, bubbling and slugging regimes inside a fluidised bed. Such maps have been obtained by visual observations of the Fluidisation interface in transparent fluidised beds. For beds which are visually inaccessible Fluidisation maps are difficult to obtain. The present work therefore attempts to model the interface travel in a vacuum fluidised bed. The pressure gradient due to the bed weight has been determined to be a main contributor for Fluidisation/deFluidisation under vacuum. A simple analytical model based on the pressure gradient (PG model) is developed to predict the interface location in a vacuum fluidised bed. For a segregated bed, the Gibilaro–Rowe (GR) model is modified and used to predict the jetsam layer growth along with the Fluidisation interface. The predictions are compared with the experimental data for minimally and highly segregated particles and it is seen that for non-segregated powders the predictions are quite accurate. Lack of sufficient knowledge of bubble characteristics, however, impeded accurate prediction of the jetsam growth especially at high flow rates. However, an approximate complete Fluidisation interface is successfully predicted using the GR–PG model.
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Investigating the effect of segregation of particles and pressure gradient on the quality of Fluidisation at sub-atmospheric pressures
Powder Technology, 2014Co-Authors: Apurv Kumar, Weimin Gao, Peter Hodgson, Subrat Das, Daniel FabijanicAbstract:Abstract Degradation in quality of Fluidisation for Group B powders under vacuum conditions occurs due to an existence of a Fluidisation interface that separates the bubbling and static bed near the minimum Fluidisation conditions. The significant pressure gradient existing due to bed weight and the particle segregation mainly affects the quality. The aim of the present work is to investigate the relative contribution of the pressure gradient and the presence of the segregation on the quality of Fluidisation in vacuum conditions. Further, the effect of morphology of the particles on Fluidisation quality is also studied. In addition, Fluidisation maps are also obtained that reveal the optimal area of operation for enhanced heat and mass transfer processes. The results indicate that the travel of interface in the bed is affected only when the level of segregation in the bed is high. For intermediate and minimal disparity in size, the quality degradation is caused by the presence of sharp pressure gradient. Changing the morphology of the particle also altered the Fluidisation characteristics of the bed and improved the quality significantly.
Apurv Kumar - One of the best experts on this subject based on the ideXlab platform.
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Analytical model to locate the Fluidisation interface in a solid–gas vacuum fluidised bed
Powder Technology, 2014Co-Authors: Apurv Kumar, Weimin Gao, Peter Hodgson, Daniel Fabijanic, Subrat DasAbstract:Abstract Vacuum fluidised beds have a distinct advantage of being operated with reduced mass consumption of the fluidising media. However, a low quality of Fluidisation reduces the opportunity to utilise the bubbling regime in vacuum fluidised beds. Fluidisation maps are often used to depict the interface between the quiescent, bubbling and slugging regimes inside a fluidised bed. Such maps have been obtained by visual observations of the Fluidisation interface in transparent fluidised beds. For beds which are visually inaccessible Fluidisation maps are difficult to obtain. The present work therefore attempts to model the interface travel in a vacuum fluidised bed. The pressure gradient due to the bed weight has been determined to be a main contributor for Fluidisation/deFluidisation under vacuum. A simple analytical model based on the pressure gradient (PG model) is developed to predict the interface location in a vacuum fluidised bed. For a segregated bed, the Gibilaro–Rowe (GR) model is modified and used to predict the jetsam layer growth along with the Fluidisation interface. The predictions are compared with the experimental data for minimally and highly segregated particles and it is seen that for non-segregated powders the predictions are quite accurate. Lack of sufficient knowledge of bubble characteristics, however, impeded accurate prediction of the jetsam growth especially at high flow rates. However, an approximate complete Fluidisation interface is successfully predicted using the GR–PG model.
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analytical model to locate the Fluidisation interface in a solid gas vacuum fluidised bed
Powder Technology, 2014Co-Authors: Apurv Kumar, Weimin Gao, Peter Hodgson, Daniel Fabijanic, Subrat DasAbstract:Abstract Vacuum fluidised beds have a distinct advantage of being operated with reduced mass consumption of the fluidising media. However, a low quality of Fluidisation reduces the opportunity to utilise the bubbling regime in vacuum fluidised beds. Fluidisation maps are often used to depict the interface between the quiescent, bubbling and slugging regimes inside a fluidised bed. Such maps have been obtained by visual observations of the Fluidisation interface in transparent fluidised beds. For beds which are visually inaccessible Fluidisation maps are difficult to obtain. The present work therefore attempts to model the interface travel in a vacuum fluidised bed. The pressure gradient due to the bed weight has been determined to be a main contributor for Fluidisation/deFluidisation under vacuum. A simple analytical model based on the pressure gradient (PG model) is developed to predict the interface location in a vacuum fluidised bed. For a segregated bed, the Gibilaro–Rowe (GR) model is modified and used to predict the jetsam layer growth along with the Fluidisation interface. The predictions are compared with the experimental data for minimally and highly segregated particles and it is seen that for non-segregated powders the predictions are quite accurate. Lack of sufficient knowledge of bubble characteristics, however, impeded accurate prediction of the jetsam growth especially at high flow rates. However, an approximate complete Fluidisation interface is successfully predicted using the GR–PG model.
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Investigating the effect of segregation of particles and pressure gradient on the quality of Fluidisation at sub-atmospheric pressures
Powder Technology, 2014Co-Authors: Apurv Kumar, Weimin Gao, Peter Hodgson, Subrat Das, Daniel FabijanicAbstract:Abstract Degradation in quality of Fluidisation for Group B powders under vacuum conditions occurs due to an existence of a Fluidisation interface that separates the bubbling and static bed near the minimum Fluidisation conditions. The significant pressure gradient existing due to bed weight and the particle segregation mainly affects the quality. The aim of the present work is to investigate the relative contribution of the pressure gradient and the presence of the segregation on the quality of Fluidisation in vacuum conditions. Further, the effect of morphology of the particles on Fluidisation quality is also studied. In addition, Fluidisation maps are also obtained that reveal the optimal area of operation for enhanced heat and mass transfer processes. The results indicate that the travel of interface in the bed is affected only when the level of segregation in the bed is high. For intermediate and minimal disparity in size, the quality degradation is caused by the presence of sharp pressure gradient. Changing the morphology of the particle also altered the Fluidisation characteristics of the bed and improved the quality significantly.