Effect of riser exit geometry on bed hydrodynamics and heat transfer in a circulating fluidized bed riser column

Evolution of mixing length empirical equation for recouping of heat from industrial waste flue gases using air‐quarry dust/iron ore

“…16 Therefore, the procedure was not standardized and could not be applied to other situations similar to ours. 17 Until now, there has not been a thorough investigation of the mechanics of heat transfer between particles and fluid in such a direct thermal contact as that provided in a suspension preheater system. 18 The riser portion of the suspension preheater system is believed to transfer approximately 75% of the heat.…”

“…In SP systems, there is a lack of evidence for the mechanism of heat transfer, and most of the research reports are proprietary 16 . Therefore, the procedure was not standardized and could not be applied to other situations similar to ours 17 . Until now, there has not been a thorough investigation of the mechanics of heat transfer between particles and fluid in such a direct thermal contact as that provided in a suspension preheater system 18 .…”

Evolution of mixing length empirical equation for recouping of heat from industrial waste flue gases using air‐quarry dust/iron ore

“…16 Therefore, the procedure was not standardized and could not be applied to other situations similar to ours. 17 Until now, there has not been a thorough investigation of the mechanics of heat transfer between particles and fluid in such a direct thermal contact as that provided in a suspension preheater system. 18 The riser portion of the suspension preheater system is believed to transfer approximately 75% of the heat.…”

“…In SP systems, there is a lack of evidence for the mechanism of heat transfer, and most of the research reports are proprietary 16 . Therefore, the procedure was not standardized and could not be applied to other situations similar to ours 17 . Until now, there has not been a thorough investigation of the mechanics of heat transfer between particles and fluid in such a direct thermal contact as that provided in a suspension preheater system 18 .…”

Development of Nusselt correlation for heat transfer studies in vertical transport duct using limestone and chalcopyrite for waste heat recovery

“…6 Necessary starting materials for cement are introduced into the transporting system, of the first stage cyclone, where they recover energy from hot gas coming out of the second cyclone. 7 The gas-solid suspension is separated in the first cyclone. Solids, at an improved temperature, are transported in to the duct between the second and third stages for further heat recovery.…”

CFD study of exit effect of high-density CFB risers with EMMS-based two-fluid model

“…In general, two types of exit can be distinguished (Grace, 1996): the "smooth" one, if there is a smooth and gentle transition via a moderate size radius bend from the riser to the cyclone entrance (Grace, 1996) and the "abrupt" one, where the exit is at a right angle to vertical direction of the flow in the riser (Lackermeier and Werther, 2002). The selection of the type of exit significantly affected the bed hydrodynamics: almost all particles were carried out by air with smooth exit, so time-averaged axial solids concentration decreased with increasing height (Chan et al, 2010;Harris et al, 2003;Pugsley et al, 1997;Reddy and Nag, 2001;Zheng and Zhang, 1994;Zheng et al, 1995). However, significant back-mixing can be observed in the riser with abrupt exit due to the collisions of solid particles with the projected roof and therefore their count-flow, this movement resulted in the fact that axial solids concentration profiles were presented as C-shaped, in other words, solids densification not only appeared in the bottom but also in the upper of bed.…”

Evolution of mixing length empirical equation for recouping of heat from industrial waste flue gases using air‐quarry dust/iron ore

“…16 Therefore, the procedure was not standardized and could not be applied to other situations similar to ours. 17 Until now, there has not been a thorough investigation of the mechanics of heat transfer between particles and fluid in such a direct thermal contact as that provided in a suspension preheater system. 18 The riser portion of the suspension preheater system is believed to transfer approximately 75% of the heat.…”

“…In SP systems, there is a lack of evidence for the mechanism of heat transfer, and most of the research reports are proprietary 16 . Therefore, the procedure was not standardized and could not be applied to other situations similar to ours 17 . Until now, there has not been a thorough investigation of the mechanics of heat transfer between particles and fluid in such a direct thermal contact as that provided in a suspension preheater system 18 .…”

Development of Nusselt correlation for heat transfer studies in vertical transport duct using limestone and chalcopyrite for waste heat recovery

“…6 Necessary starting materials for cement are introduced into the transporting system, of the first stage cyclone, where they recover energy from hot gas coming out of the second cyclone. 7 The gas-solid suspension is separated in the first cyclone. Solids, at an improved temperature, are transported in to the duct between the second and third stages for further heat recovery.…”

CFD study of exit effect of high-density CFB risers with EMMS-based two-fluid model

“…In general, two types of exit can be distinguished (Grace, 1996): the "smooth" one, if there is a smooth and gentle transition via a moderate size radius bend from the riser to the cyclone entrance (Grace, 1996) and the "abrupt" one, where the exit is at a right angle to vertical direction of the flow in the riser (Lackermeier and Werther, 2002). The selection of the type of exit significantly affected the bed hydrodynamics: almost all particles were carried out by air with smooth exit, so time-averaged axial solids concentration decreased with increasing height (Chan et al, 2010;Harris et al, 2003;Pugsley et al, 1997;Reddy and Nag, 2001;Zheng and Zhang, 1994;Zheng et al, 1995). However, significant back-mixing can be observed in the riser with abrupt exit due to the collisions of solid particles with the projected roof and therefore their count-flow, this movement resulted in the fact that axial solids concentration profiles were presented as C-shaped, in other words, solids densification not only appeared in the bottom but also in the upper of bed.…”

Evolution of mixing length empirical equation for recouping of heat from industrial waste flue gases using air‐quarry dust/iron ore

“…16 Therefore, the procedure was not standardized and could not be applied to other situations similar to ours. 17 Until now, there has not been a thorough investigation of the mechanics of heat transfer between particles and fluid in such a direct thermal contact as that provided in a suspension preheater system. 18 The riser portion of the suspension preheater system is believed to transfer approximately 75% of the heat.…”

“…In SP systems, there is a lack of evidence for the mechanism of heat transfer, and most of the research reports are proprietary 16 . Therefore, the procedure was not standardized and could not be applied to other situations similar to ours 17 . Until now, there has not been a thorough investigation of the mechanics of heat transfer between particles and fluid in such a direct thermal contact as that provided in a suspension preheater system 18 .…”

Development of Nusselt correlation for heat transfer studies in vertical transport duct using limestone and chalcopyrite for waste heat recovery

“…6 Necessary starting materials for cement are introduced into the transporting system, of the first stage cyclone, where they recover energy from hot gas coming out of the second cyclone. 7 The gas-solid suspension is separated in the first cyclone. Solids, at an improved temperature, are transported in to the duct between the second and third stages for further heat recovery.…”

CFD study of exit effect of high-density CFB risers with EMMS-based two-fluid model

“…In general, two types of exit can be distinguished (Grace, 1996): the "smooth" one, if there is a smooth and gentle transition via a moderate size radius bend from the riser to the cyclone entrance (Grace, 1996) and the "abrupt" one, where the exit is at a right angle to vertical direction of the flow in the riser (Lackermeier and Werther, 2002). The selection of the type of exit significantly affected the bed hydrodynamics: almost all particles were carried out by air with smooth exit, so time-averaged axial solids concentration decreased with increasing height (Chan et al, 2010;Harris et al, 2003;Pugsley et al, 1997;Reddy and Nag, 2001;Zheng and Zhang, 1994;Zheng et al, 1995). However, significant back-mixing can be observed in the riser with abrupt exit due to the collisions of solid particles with the projected roof and therefore their count-flow, this movement resulted in the fact that axial solids concentration profiles were presented as C-shaped, in other words, solids densification not only appeared in the bottom but also in the upper of bed.…”