Fours rotatifs: Modèle dynamique du mouvement du lit

Perron, Jean; Bui, R. T.

doi:10.1002/cjce.5450720104

Cited by 8 publications

(6 citation statements)

References 16 publications

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“…It can be seen that the rotational effect produces a significant influence over the range of 0 to 0.083 rps and that above this range the influence is negligible. This activity is associated with bed transverse dissipation potency and its behavior agrees with Perron's model (Perron and Bui, 1994). Table 1.…”

Section: Resultssupporting

confidence: 75%

Niobium carbide synthesis by solid-gas reaction using a rotating cylinder reactor

Fontes

Gomes

Oliveira

et al. 2004

Braz. J. Chem. Eng.

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-A rotating cylinder reactor was designed for the synthesis of niobium carbide powders at 1173 K. Niobium carbide, NbC, was prepared by carbothermal reduction starting from commercial niobium pentoxide powders. The reactor was heated using a custom-made, two-part, hinged, electric furnace with programmable temperature control. The design and operational details of the reactor are presented. The longitudinal temperature gradient inside the reactor was determined. Total reaction time was monitored by a gas chromatograph equipped with an FID detector for determination of methane concentrations. The results show that time of reaction depended on rotation speed. NbC was also prepared in a static-bed alumina reactor using the same conditions as in the previous case. The niobium carbide powders were characterized by X-ray diffraction and compared with commercially available products. Morphological, particle size distribution and surface area analyses were obtained using SEM, LDPS and BET, respectively. Therefore, the present study offers a significant technological contribution to the synthesis of NbC powders in a rotating cylinder reactor.

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Section: Resultssupporting

confidence: 75%

Niobium carbide synthesis by solid-gas reaction using a rotating cylinder reactor

Fontes

Gomes

Oliveira

et al. 2004

Braz. J. Chem. Eng.

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“…14 In the transient case, there is axial variation of Q. A material balance on an axial element gives 1,5 ∂A ∂t…”

Section: Modelingmentioning

confidence: 99%

“…Transient behavior of the solids motion can occur in a number of industrial situations such as startup, irregularities in the feed rate, and fluctuations in the feed material properties. Perron and Bui proposed a nonlinear model to predict the discharge rate following a step change in (i) the feed rate, (ii) the rotation speed, (iii) the discharge dam height, and (iv) the axis of inclination. The model was based on an analysis by Perron and Bui, as modified by Sai et al, of the axial velocity of the active layer and the bed as a whole; Perron and Bui used a semiempirical model with fitted parameters for solid transport based on dimensional analysis and on the determination of an apparent viscosity characterizing the flow behavior of the bed.…”

Section: Introductionmentioning

confidence: 99%

Transient Granular Flows in an Inclined Rotating Cylinder: Filling and Emptying

Scott

Davidson

Cheah

et al. 2008

Ind. Eng. Chem. Res.

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This paper reports the results of an experimental and theoretical study into transient granular flows in an inclined, slowly rotating cylinder. The granular materials used were sand, poppy seeds, and glass beads. The following situations have been studied: (i) feeding an initially empty cylinder, (ii) emptying a cylinder which is initially in steady state with equal feed and discharge flow rates, and (iii) the motion of a localized pile of granular material through the cylinder. Axial profiles of bed depth and discharge flow rates have been measured. The mechanistic model used here has previously been used to describe the transient response to large step changes in feed rate, rotation speed and angle of inclination; it has no free parameters. There is good agreement between theory and experiment for sand and poppy seeds, but there are discrepancies for glass beads, which under some conditions flow in a different way from sand and poppy seeds.

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“…Representing the solid phase as a fluid flowing through the rotary dryer has also been considered. In one case, the fluid conservation and movement equations were solved (Ferron and Singh, 1991), and in another case, it has been modeled with dimensional and rheological analysis where an apparent viscosity was defined (Perron and Bui, 1990Bui, , 1994. Bui et al (1995), in a thorough three-dimensional steady-state modeling of a rotary kiln, used three apparent viscosities to represent the granular bed motion.…”

Section: Introductionmentioning

confidence: 99%

Modeling of the Solids Transportation within an Industrial Rotary Dryer: A Simple Model

Duchesne

Thibault

Bazin

1996

Ind. Eng. Chem. Res.

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To better understand the underlying phenomena taking place in an industrial rotary dryer and to determine the optimum operating conditions, a simulator in which the solids transportation, the gas flow, and the heat and mass transfer are modeled is currently being developed. This paper describes the use of interactive perfect mixers in series to model the solids transportation within an industrial rotary dryer, on the basis of an experimental residence time distribution curve (RTD). Two simple models are proposed : a series of perfect well-mixed interacting tanks and a modified Cholette-Cloutier model. The first model is not able to account for the nonideal behavior of the solids transportation in the rotary dryer. To account for the characteristic extended tail of the RTD curves observed in industrial dryers, in a second model, the solid phase is divided between an active and a dead zone. This model, with 36 cells and 25% of the volume occupied by the dead zones, modeled very well the industrial RTD curve. In addition, the model produces bed depth and axial velocity profiles that are consistent with those reported in the literature.

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Fours rotatifs: Modèle dynamique du mouvement du lit

Cited by 8 publications

References 16 publications

Niobium carbide synthesis by solid-gas reaction using a rotating cylinder reactor

Niobium carbide synthesis by solid-gas reaction using a rotating cylinder reactor

Transient Granular Flows in an Inclined Rotating Cylinder: Filling and Emptying

Modeling of the Solids Transportation within an Industrial Rotary Dryer: A Simple Model

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