Annulus leakage and distribution of the fluid flow in a liquid spout–fluid bed with a draft tube

Erbil, Ayşe Çeçen

doi:10.1016/j.ces.2003.05.005

Cited by 11 publications

(6 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The effect of the particle size is rather interesting in that the calculated average shear stress in the draft tube system for the larger particles studied by Ceçen-Erbíl ( , ) is consistently higher than that for the smaller particles. The same trend is also observed for the fictive fluidized bed of identical materials, the smaller particle size results in lower shear stress values (Figure ).…”

Section: Resultsmentioning

confidence: 92%

“…Due to the scarcity of spout-fluid bed data permitting the calculation of shear stresses and velocity gradients, the analysis is restricted to the data of Grbavcic et al () and Çeçen Erbıl ( , ). The spout-fluid bed with the 1.94 mm glass particles has an Re t of 469; therefore, the flow of this system is assumed to result in transition flow conditions whereas the spout-fluid bed with the 3 mm glass particles has an Re t of 933 indicating turbulent flow ( , ).…”

Section: Resultsmentioning

confidence: 99%

“…All raw data necessary for the calculation of the energy dissipation parameters, including the draft tube voidage and the dynamic pressure gradient inside the draft tube, are those of Grbavcic et al () and Çeçen Erbıl ( , ). In both cases, the equipment used is a spout-fluid bed of semi-circular geometry.…”

Section: Methodsmentioning

confidence: 99%

“…The variables measured include the total flow rate into the spout-fluid bed alongside with the spouting and annulus inlet flow rates and the pressure profiles inside the draft tube. In the experiments conducted by Çeçen Erbıl ( , ), the spouting inlet flow and the annulus liquid inlet flow were introduced into the spouted bed by two independent lines connected to pumps and flow meters. Air was introduced into the annulus through the same flow distributor that was used for the annulus liquid.…”

Section: Methodsmentioning

confidence: 99%

“…The voidage and the particle velocity in the draft tube were calculated by the variational method of Grbavcic et al (). Table lists the voidage, particle velocity, and superficial flow rate ( U d ) inside the draft tube together with the experimental conditions used by Çeçen Erbıl ( , ).…”

Section: Methodsmentioning

confidence: 99%

See 4 more Smart Citations

Assessment of the Energy Dissipation Parameters Inside the Draft Tube of a Liquid Spout-Fluid Bed

Erbil

Turan

2005

Environ. Sci. Technol.

View full text Add to dashboard Cite

Spouted beds are fluid-particle contactors in which the fluid is introduced centrally through a nozzle instead of a distributor plate, resulting in a regular particle circulation pattern. To assess the suitability of such sytems to environmental engineering applications such as filter backwashing and biofilm systems, a priori knowledge of the energy dissipation parameters is essential. A new model is developed for evaluating the energy dissipation parameters inside the draft tube of spout-fluid beds. The shear stress, velocity gradient, and turbulence fluctuation parameters in the draft tube of a liquid spout-fluid bed are calculated with the help of an energy equation for flows carrying suspensions and the experimentally determined pressure losses inside the draft tube and compared with results for particulately fluidized beds. A spout-fluid bed with a draft tube provides higher shear stress inside the draft tube than a fluidized bed. The mean velocity gradient in the draft tube is comparable to and higher than in a fluidized bed and increases with solids fraction. The turbulence dissipation coefficient decreases very slightlywith increasing solids fraction for both systems. Consequently, according to the model calculations, a spout-fluid bed with a draft tube can be an alternative to the classical fluidized bed filter backwashing system.

show abstract

Section: Resultsmentioning

confidence: 92%