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Effect of perforated ratios of distributor on the fluidization characteristics in a gas-solid fluidized bed / Shuqin Dong in Industrial & engineering chemistry research, Vol. 48 N°1 (Janvier 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°1 (Janvier 2009) . - P. 517-527 Titre : Effect of perforated ratios of distributor on the fluidization characteristics in a gas-solid fluidized bed Type de document : texte imprimé Auteurs : Shuqin Dong, Editeur scientifique ; Changqing Cao, Editeur scientifique ; Chongdian Si, Editeur scientifique Année de publication : 2009 Article en page(s) : P. 517-527 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Gas−Solid  Fluid  dynamics Résumé : A gas−solid fluidized bed, 0.14 m in diameter and 1.6 m in height, was employed to investigate systematically the effects of perforated ratios of distributor on fluidization characteristics with air as gas phase and fluid catalytic cracking particles as solid phase. The distributions of the distributor pressure drop, solid particle concentration, and bed pressure drop were obtained by means of different perforated ratios of distributors. The particle concentration distribution and bed pressure drop were measured by a PV-6A particles velocity measurer and a U-manometer, respectively. The parameters of bed pressure drop, distributor pressure drop, the instantaneous evolution of bubbles, and profile of radial solid holdups adopted three perforated ratios of distributors were simulated using computational fluid dynamics code Fluent 6.2. The results showed that the distributor pressure drop decreased with increasing perforated ratios and decreasing superficial gas velocity. The global solid holdup decreased from the wall to center region, and it had parabolic concentration profile under pressure-driven force for different perforated ratios of three distributors investigated. However, the distribution of radial solid holdup was more homogeneous, and it had a better agreement with experiment values for perforated ratio 0.46% of distributor than that for perforated ratio 0.86 or 1.10% of distributors. The bubble size at the region of distributor decreased with increasing perforated ratio of distributors, and it had more obvious circulation motion of solid particles for the perforated ratio 0.46% of distributor than that for perforated ratio 0.86 or 1.10% of distributor. The bed pressure drop and root mean square (rms) of bed pressure drop in gas−solid fluidized bed appeared differently for three perforated ratios of distributors. The rms of bed pressure drop for the perforated ratio 0.46% of distributor was larger than that for perforated ratio 0.86 or 1.10% of distributors, and the larger discrepancy occurred as the perforated ratio of distributor was 0.46%. The numerical simulation results agreed well with the experimental data at low superficial gas velocity for calculation of distributor pressure drop. However, larger error occurred at high superficial gas velocity. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801073r [article] Effect of perforated ratios of distributor on the fluidization characteristics in a gas-solid fluidized bed [texte imprimé] / Shuqin Dong, Editeur scientifique ; Changqing Cao, Editeur scientifique ; Chongdian Si, Editeur scientifique . - 2009 . - P. 517-527. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°1 (Janvier 2009) . - P. 517-527 Mots-clés : Gas−Solid  Fluid  dynamics Résumé : A gas−solid fluidized bed, 0.14 m in diameter and 1.6 m in height, was employed to investigate systematically the effects of perforated ratios of distributor on fluidization characteristics with air as gas phase and fluid catalytic cracking particles as solid phase. The distributions of the distributor pressure drop, solid particle concentration, and bed pressure drop were obtained by means of different perforated ratios of distributors. The particle concentration distribution and bed pressure drop were measured by a PV-6A particles velocity measurer and a U-manometer, respectively. The parameters of bed pressure drop, distributor pressure drop, the instantaneous evolution of bubbles, and profile of radial solid holdups adopted three perforated ratios of distributors were simulated using computational fluid dynamics code Fluent 6.2. The results showed that the distributor pressure drop decreased with increasing perforated ratios and decreasing superficial gas velocity. The global solid holdup decreased from the wall to center region, and it had parabolic concentration profile under pressure-driven force for different perforated ratios of three distributors investigated. However, the distribution of radial solid holdup was more homogeneous, and it had a better agreement with experiment values for perforated ratio 0.46% of distributor than that for perforated ratio 0.86 or 1.10% of distributors. The bubble size at the region of distributor decreased with increasing perforated ratio of distributors, and it had more obvious circulation motion of solid particles for the perforated ratio 0.46% of distributor than that for perforated ratio 0.86 or 1.10% of distributor. The bed pressure drop and root mean square (rms) of bed pressure drop in gas−solid fluidized bed appeared differently for three perforated ratios of distributors. The rms of bed pressure drop for the perforated ratio 0.46% of distributor was larger than that for perforated ratio 0.86 or 1.10% of distributors, and the larger discrepancy occurred as the perforated ratio of distributor was 0.46%. The numerical simulation results agreed well with the experimental data at low superficial gas velocity for calculation of distributor pressure drop. However, larger error occurred at high superficial gas velocity. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801073r

Flow characteristics in a jetting fluidized bed with acoustic assistance / Qingjie Guo in Industrial & engineering chemistry research, Vol. 49 N° 16 (Août 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7638–7645 Titre : Flow characteristics in a jetting fluidized bed with acoustic assistance Type de document : texte imprimé Auteurs : Qingjie Guo, Auteur ; Chongdian Si, Auteur ; Zhang, Jian, Auteur Année de publication : 2010 Article en page(s) : pp. 7638–7645 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Acoustic  Fluidized  Bed Résumé : A jetting fluidized bed with acoustic assistance was employed to investigate the jet penetration depth and particle concentration profiles using an optical fiber probe. One type of FCC and two types of quartz sand particles were used as bed materials in this study. Experimental results indicated that the jet penetration depth is increased with increasing fluidizing number, jet nozzle diameter, and jet gas velocity, respectively. The jet penetration depth is decreased with an increase in particle diameter and in particle density. The semitheoretical correlations were developed to predict the jet penetration depth with and without the sound assistance. In the bubbling region, particle concentration increased with an increase in sound pressure level, which had a maximal value at a sound frequency of 150 Hz. The sound excitation had a slight influence on the particle concentration profiles in the jetting region and dense-phase particle compression region. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9016573 [article] Flow characteristics in a jetting fluidized bed with acoustic assistance [texte imprimé] / Qingjie Guo, Auteur ; Chongdian Si, Auteur ; Zhang, Jian, Auteur . - 2010 . - pp. 7638–7645. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7638–7645 Mots-clés : Acoustic  Fluidized  Bed Résumé : A jetting fluidized bed with acoustic assistance was employed to investigate the jet penetration depth and particle concentration profiles using an optical fiber probe. One type of FCC and two types of quartz sand particles were used as bed materials in this study. Experimental results indicated that the jet penetration depth is increased with increasing fluidizing number, jet nozzle diameter, and jet gas velocity, respectively. The jet penetration depth is decreased with an increase in particle diameter and in particle density. The semitheoretical correlations were developed to predict the jet penetration depth with and without the sound assistance. In the bubbling region, particle concentration increased with an increase in sound pressure level, which had a maximal value at a sound frequency of 150 Hz. The sound excitation had a slight influence on the particle concentration profiles in the jetting region and dense-phase particle compression region. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9016573

Fluidization characteristics of binary mixtures of biomass and quartz sand in an acoustic fluidized bed / Chongdian Si in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9773–9782 Titre : Fluidization characteristics of binary mixtures of biomass and quartz sand in an acoustic fluidized bed Type de document : texte imprimé Auteurs : Chongdian Si, Auteur ; Qingjie Guo, Auteur Année de publication : 2009 Article en page(s) : p. 9773–9782 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Fluidization  characteristics  Binary  mixtures  Biomass  Quartz  sand  Acoustic  fluidized  bed Résumé : The fluidization behaviors of binary mixtures of biomass and quartz sand were investigated in an acoustic bubbling fluidized bed. Two kinds of biomass particles, sawdust and wheat stalk, were employed in this test. The experiments indicated that the addition of quartz sand can improve the fluidization quality of biomass. The minimum fluidization velocity of the mixtures increased with increasing biomass content in the mixtures. A new correlation was developed for predicting the minimum fluidization velocity of different binary mixtures. The minimum fluidization velocity decreased with increasing sound pressure level and had a minimum value over the sound frequency range of 100−200 Hz. Such an acoustic fluidized bed operated in a stable or unstable fluidization regime depending on the operating conditions. According to the slope of a plot of standard deviations, unstable fluidization can be expected if the slope is greater than 50, and stable fluidization can be expected if the value is less than or equal to 50. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801070z [article] Fluidization characteristics of binary mixtures of biomass and quartz sand in an acoustic fluidized bed [texte imprimé] / Chongdian Si, Auteur ; Qingjie Guo, Auteur . - 2009 . - p. 9773–9782. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9773–9782 Mots-clés : Fluidization  characteristics  Binary  mixtures  Biomass  Quartz  sand  Acoustic  fluidized  bed Résumé : The fluidization behaviors of binary mixtures of biomass and quartz sand were investigated in an acoustic bubbling fluidized bed. Two kinds of biomass particles, sawdust and wheat stalk, were employed in this test. The experiments indicated that the addition of quartz sand can improve the fluidization quality of biomass. The minimum fluidization velocity of the mixtures increased with increasing biomass content in the mixtures. A new correlation was developed for predicting the minimum fluidization velocity of different binary mixtures. The minimum fluidization velocity decreased with increasing sound pressure level and had a minimum value over the sound frequency range of 100−200 Hz. Such an acoustic fluidized bed operated in a stable or unstable fluidization regime depending on the operating conditions. According to the slope of a plot of standard deviations, unstable fluidization can be expected if the slope is greater than 50, and stable fluidization can be expected if the value is less than or equal to 50. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801070z