Hydrodynamics of a spouted bed with a porous draft tube containing a small amount of finer particles

Ishikura, Toshifumi; Nagashima, Hiroshi; Ide, Mitsuharu

doi:10.1016/s0032-5910(02)00321-2

Cited by 96 publications

(97 citation statements)

References 25 publications

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“…However, plain spouted beds are rarely used in industry due to scaling-up difficulties, but the insertion of a draft tube is the way of overcoming this limitation. In fact, the use of a draft tube has several advantages, such as the possibility of operating with deeper beds, a lower gas flow rate and pressure drop required for the operation, higher stability, and a better control of solid circulation [8,[19][20][21][22][23][24]. Furthermore, draft tubes are simple low-cost devices that allow attaining several gas-solid contact regimes in the bed.…”

Section: Introductionmentioning

confidence: 99%

“…The simplest one is the nonporous draft tube, whose main advantages are the low gas flow rate and pressure drop required for operation and the high bed stability under any operating condition. However, the gassolid contact achieved is poor due to gas bypassing through the annulus [20]. The most influential parameter on the operation with nonporous draft tubes is the height of the entrainment zone.…”

Section: Introductionmentioning

confidence: 99%

“…This tube is an interesting option in those processes in which the gas plays an active role, such as chemical reactions or drying. Apart from a better gas-solid contact, an additional advantage of porous draft tubes over nonporous ones lies in the higher circulation rates achieved [20,29,30].…”

Section: Introductionmentioning

confidence: 99%

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Effect of Temperature on Fine Particle Drying in a Draft‐Tube Conical Spouted Bed

et al. 2011

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The performance of a draft-tube conical spouted bed for drying fine particles under batch operating conditions has been assessed at several temperatures using nonporous and open-sided draft tubes, and the results have been compared with those obtained when operating without a draft tube. In order to ascertain the influence of temperature on drying, experimental runs have been carried out in the 25-300°C temperature range. The open-sided draft tube provides the best performance due to the excellent gas-solid contact attained with this device, which enables shorter drying times. A maximum air temperature of 200°C is recommended for energy optimization. An open-sided tube protruding above the stagnant bed by at least 2/3 of the latter's height produces much lower and denser fountains than a tube flush with the upper surface of the bed.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Effect of Temperature on Fine Particle Drying in a Draft‐Tube Conical Spouted Bed

et al. 2011

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“…Those existing studies mainly focused on the dependence of solid circulation rate on operating variables such as draft tube diameter, particle size, length of entrainment region, gas velocity, etc. [22][23][24][25][26][27]. It is also impossible to extend empirical correlations and theoretical analyses developed from the experiments of conventional systems to the applications of DTSBs.…”

Section: Introductionmentioning

confidence: 99%

Effects of Draft Tubes on Particle Velocity Profiles in Spouted Beds

Zhao

Yao

2006

Chem Eng & Technol

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The vertical particle velocity profiles in a full-column cylindrical conical spouted bed, with or without a draft tube, are measured using a fibre optic probe system. The profiles have different characteristics for a draft tube spouted bed (DTSB) than for a conventional spouted bed (CSB). The spout of a CSB consists of a central flow where particle velocities fit exponential distributions, and a boundary layer where particle velocities are nearly uniform. The spout of a DTSB has no boundary layer and its radial particle velocity profiles are approximately linear. The particle velocities in the spout of a DTSB increase when superficial gas velocity increases, draft tube diameter decreases, or when entrainment height decreases. A kinematic model has been used to simulate the granular flow in the annulus of a CSB and DTSB, and they are compared with the experiments. The particle velocities in the annulus of a DTSB are much lower than that of a CSB. Their radial profiles are also different with a CSB. The dependence of particle velocities in the annulus of a DTSB on superficial gas velocity, draft tube diameter, and entrainment height are also discussed. One concludes that the draft tube diameter and entrainment height are two key factors for the solid circulation rate of a DTSB.

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“…Wang Shuyan et al [44] Simulated the gas and particle's behavior in a porous draft tube spouted bed dryer with Fluent 6.5 software in 2010; and validated their results by the Ishikura et al [45] empirical data. DEM simulation on particle mixing in dry and wet particles spouted bed was reported in reference number [46].…”

Section: Introductionmentioning

confidence: 96%

Transport phenomena study in a solar spouted bed dryer within a draft tube

Esmailie

Ghadamian

Aminy

2017

Env Prog and Sustain Energy

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This research investigated a high drying rate solar dryer with low-intensity energy consumption. In a brief issue, the solar spouted bed dryer was designed, fabricated and tested through this study. To cover this purpose, a 1D dynamic model was developed for this dryer's bed section. The mentioned accurate model is able to predict this type of solar dryer behavior which includes mass, momentum and energy transfer phenomena. The mentioned model solves the governing equations-mass, momentum, and energy balance equations-simultaneously using MATLAB software. By this system test pilot modeling and experiments, Design and manufacture of a high drying rate solar dryer with low energy intensity are achieved. Comparison between the model and experimental results shows that the maximum error percentage related to output profiles were approximately less than 3.6% that consider an appropriate band of errors. Based on experiments, the system is able to eliminate 85,500 mg water from 150 g corn grains during 90 min test interval. The considerable achievement contributed to the energy consumption intensity is equal to 93.3 kJ/g of corn, which can be a valuable energy heat rate.

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Hydrodynamics of a spouted bed with a porous draft tube containing a small amount of finer particles

Cited by 96 publications

References 25 publications

Effect of Temperature on Fine Particle Drying in a Draft‐Tube Conical Spouted Bed

Effect of Temperature on Fine Particle Drying in a Draft‐Tube Conical Spouted Bed

Effects of Draft Tubes on Particle Velocity Profiles in Spouted Beds

Transport phenomena study in a solar spouted bed dryer within a draft tube

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