Holdup of fine particles in the fluidized dense bed of the multisolid pneumatic transport bed

Kitano, Kunihiro; Wisecarver, Keith; Satija, Sunil; Fan, Liang Shih

doi:10.1021/ie00079a028

Cited by 12 publications

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…February 1994 hancement of fine solids holdup because of the interactions between fine and coarse particles. According to Kitano et al (1988), who examined the fine particle holdup in a fluidized dense bed of a multisolid pneumatic transport bed, this interaction force is proportional to the size of the coarse particles and inversely proportional to the size of the fine particles. The critical solids circulation rates at the gas velocity of 2.3 m/s are about 12,4.5 and 8 kg/m2.s for the systems of FCC-CPE, FCC-GB and PE-CPE, respectively.…”

Section: Aiche Journalmentioning

confidence: 99%

Hydrodynamic behavior of circulating fluidized bed with polymeric particles

Jiang

Liang

et al. 1994

AIChE Journal

View full text Add to dashboard Cite

Section: Aiche Journalmentioning

confidence: 99%

Hydrodynamic behavior of circulating fluidized bed with polymeric particles

Jiang

Liang

et al. 1994

AIChE Journal

View full text Add to dashboard Cite

“…Therefore, it is not clear whether particle segregation is caused by the differences in particle densities or sizes, and/or their combination. In a binary particle system, it was observed that the solids holdup of fine particles in a riser can be enhanced by the addition of coarse particles (Liu et al, 1979;Kitano et al, 1988;and Bi et al, 1992). The terminal velocity and minimum fluidization velocity of coarse particles are smaller in systems with fine particles (Satija and Fan, 1985;Na et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Flow Characteristics of Coal Ash in a Circulating Fluidized Bed

Zhang

Jiang

Fan

1998

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Solids flow characteristics of coal ash are investigated with the measurement of the local solids flux, local solids concentration, and spatial distribution of particle size. Two sets of the solids sampling probe are used to quantify the local solids flux at different radial and axial locations. The macroscopic flow structure is presented by analyzing the radial profiles of solids flux and the local particle size distributions, while the mesoscale flow structure is illustrated on the basis of probability density function of instantaneous solids concentration, the intermittency index, and the cluster frequency. It is found that both macroscopic and mesoscopic structures of gas−solid flow of coal ash are different from those of commonly studied fluid catalytic cracking and sand particles. The differences include higher upward and downward solids fluxes in the lower dense region, significant particle segregation, and more uniform annular flow. Furthermore, a semiempirical model taking into consideration the higher slip velocity between gas and solids is developed to account for the radial profiles of the solids flux in the upper dilute region of the riser.

show abstract

The investigations of gas-powder two phase flow in packed bed

2000

View full text Add to dashboard Cite

Gas-powder two-phase flow in packed beds was investigated and the results are presented in this paper. The experimental system, in which the glass powder and air gas were injected into the lower part of the packed bed allowed the estimation of the influence of gas velocity, powder feed rate, powder and packed particles diameter on pressure loss and total hold up of powder in the packed bed. On the base of the experimental results, a one-dimensional mathematical model for gas-powder two-phase flow in the packed bed was developed. This model allows satisfactory prediction of the pressure loss and the hold ups of powders. The maximum deviation between calculated and measured values was less than ±15%. Futhermore, the conditions when the blockade of the flow occurs were defined. The additional pressure loss (expressed by Fk) due to the gravitional force of powders and the collision and the friction between powders and 1.8462 74.13packed particles, was correlated with Froude number as: Fk = -_ . + .._ -for the void fraction in the packed bed EO of between 1' ;.2 F)0.7309) 1.1670 0.36 to 0.410r Fk =--2-+ 8181.10 for EO =0.42. r; Untersuchungen zur zweiphasigen (Gas + Staub) Durchstromung einer Stoffschicht. Untersucht wurde die zweiphasige Durchstromung (Gas + Staub) einer Stoffschicht: die Ergebnisse werden vorgestellt. FOr ein Modellsystem (Stoffschicht aus Glaskugeln und Glasstaub) wurde der EinfluB der Gasgeschwindigkeit, Staubmenge im Gas, GroBe der Staubpartikel sowie der Stoffschichtpartikel auf den Stromungswiderstand und auf die Menge des eingeschlossenen Staubes in der Schicht bestimmt. Auf der Basis der Laboruntersuchungen wurde ein mathematisches eindimesionales Modell entwickelt, das die zweiphasige Durchstrornunq (Gas + Staub) der Stoffschicht beschreibt. Das Model berOcksichtigt den eingeschlossenen Staub und den Druckverlust in der Schicht. Mit diesem Modell konnen der Stromungswiderstand und die in der Schicht eingeschlossene Staubmenge mit einer Genauigkeit von ±15% berechnet werden. Weiterhin wurde die Abhangigkeit eines Koeffizienten, der den zusatzlichen Widerstand, der durch die Gravitation, den ZusammenstoB und die Reibung der Staubpartikel verursachten EinfluB zusammenfaBt, von der Froude-Zahl Fk = 1.84~2+ (~~713~9) berechnet: G{) liegt steel research 71 (2000) NO.8

show abstract

Holdup of fine particles in the fluidized dense bed of the multisolid pneumatic transport bed

Cited by 12 publications

References 3 publications

Hydrodynamic behavior of circulating fluidized bed with polymeric particles

Hydrodynamic behavior of circulating fluidized bed with polymeric particles

Flow Characteristics of Coal Ash in a Circulating Fluidized Bed

The investigations of gas-powder two phase flow in packed bed

Contact Info

Product

Resources

About