Solids Circulation Rate in Screen-Bottomed Spouted Bed with Draft-Tube.

Hattori, Hirotsugu; Nagai, Takashi; Ohshima, Yasutaka; Yoshida, Mana; Nagata, Atsushi

doi:10.1252/jcej.31.633

Cited by 16 publications

(8 citation statements)

References 2 publications

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“…The use of a draft tube causes changes in the hydrodynamics and solid circulation rate of spouted beds. − The performance of the lower conical section of the contactor is different when the draft tube is used, and largely depends on the bed geometry, draft tube diameter, length of the entrainment zone, and operating conditions. ,,− …”

Section: Introductionmentioning

confidence: 99%

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Particle Cycle Times and Solid Circulation Rates in Conical Spouted Beds with Draft Tubes of Different Configuration

Altzibar

López

Estiati

et al. 2013

Ind. Eng. Chem. Res.

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Particle cycle times (average, maximum, and minimum) have been measured in draft tube conical spouted beds for different geometric factors of the contactor (angle and gas inlet diameter), draft tubes (diameter, height of the entrainment zone, and width of the faces) and under different operating conditions (particle density). On the basis of the results, the effects of the type of draft tube and different factors of the contactor/draft tube/particle system have been studied, and those of greater influence have been determined. The results show that particle cycle times and solid circulation rates are highly dependent on the type of draft tube, solid density, and contactor angle. Open-sided draft tubes are the ones with the highest solid circulation rate with stable spouting performance. Therefore, this internal device is a suitable option for scaling up spouted beds with a hydrodynamic performance similar to those without tubes.

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Section: Introductionmentioning

confidence: 99%

“…The few papers dealing with the solid circulation rate in draft tube spouted beds report the influence on particle circulation of operating and geometric variables, such as draft tube diameter, particle size, height of entrainment zone, contactor angle, and gas velocity. ,,,,,− …”

Section: Introductionmentioning

confidence: 99%

Particle Cycle Times and Solid Circulation Rates in Conical Spouted Beds with Draft Tubes of Different Configuration

Altzibar

López

Estiati

et al. 2013

Ind. Eng. Chem. Res.

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show abstract

“…In fact, the inlet diameter should be smaller than 20–30 times the average particle diameter in order to avoid a slugging regime and achieve spouting status. Draft tubes are used to achieve stability out of this range, but they change the hydrodynamics and solid circulation rate of spouted beds. − The lower conical section of the contactor performs differently when the draft tube is used and depends largely on the bed geometry, draft tube diameter, length of the entrainment zone, and operating conditions. − ,− …”

Section: Introductionmentioning

confidence: 99%

Operating and Peak Pressure Drops in Conical Spouted Beds Equipped with Draft Tubes of Different Configuration

Altzibar

López

Bilbao

et al. 2013

Ind. Eng. Chem. Res.

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Operating and peak pressure drops have been studied in conical spouted beds equipped with draft tubes of different configuration using materials of different size. The draft tubes used are nonporous and open-sided ones. Based on an experimental design, the factors of greater influence on both pressure drops have been determined and general correlations valid for fine and coarse materials have been proposed for predicting the operating pressure drop and peak pressure drop with each type of draft tube. The results show that conical spouted beds equipped with draft tubes give way to lower operating and peak pressure drops than those without draft tube. A comparison of draft tube systems reveals that nonporous tubes give way to the lowest values of both pressure drops, but the solid circulation rates and the gas−solid contact efficiency are poorer than those with open-sided draft tube systems.

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“…From this point of view, Claflin and Fane (1983, l984) studied the permeability of gas from the inside of the tube to the annulus region by using a cylindrical sieve screen with a large opening ratio as the draft tube. Also, Hattori and Nagai (1996) and Hattori et al (1998) examined the characteristics of spouted bed with a draft tube at a uniform gas flow without using the gas inlet nozzle and the flow ratio of gas which passed through the annulus considerably increased. The authors also studied the flow characteristics of spouted bed (Ishikura et al, 1996, 2003) by using cylindrical porous draft tube, including the cases of binary particle mixtures with coarse and fine particles.…”

Section: Introductionmentioning

confidence: 99%

Effect of the tube shape on gas and particle flow in spouted beds with a porous draft tube

2009

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Flow characteristics of a spouted bed with a porous draft tube have been investigated experimentally. In this study, both a cylindrical tube and a conical–cylindrical tube were used as the draft tube. As a result, the efficiency of gas–solid contact and solids circulation rate in the bed were considerably improved by inserting a conical–cylindrical porous draft tube into the bed. Moreover, it was confirmed that the gas flow rate through the annulus reached nearly the level of a conventional spouted bed by using conical–cylindrical porous draft tube.

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Solids Circulation Rate in Screen-Bottomed Spouted Bed with Draft-Tube.

Cited by 16 publications

References 2 publications

Particle Cycle Times and Solid Circulation Rates in Conical Spouted Beds with Draft Tubes of Different Configuration

Particle Cycle Times and Solid Circulation Rates in Conical Spouted Beds with Draft Tubes of Different Configuration

Operating and Peak Pressure Drops in Conical Spouted Beds Equipped with Draft Tubes of Different Configuration

Effect of the tube shape on gas and particle flow in spouted beds with a porous draft tube

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