Evaluation of flow regimes in a semi‐cylindrical spouted bed through statistical, mutual information, spectral and Hurst's analysis

Oliveira, Wanderley Pereira de; Souza, C. R. F.; Lim, C. Jim; Grace, John R.

doi:10.1002/cjce.20055

Cited by 17 publications

(13 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Autocorrelation and frequency analysis of PF signals have been used to characterize fluidization and spouting flow regimes by several previous authors (Karamavruc and Clark, 1997; Johnsson et al, 2000; Trnka et al, 2000; Wang et al, 2001; Xu et al, 2004a; Dahikar and Sonolikar, 2006; Piskova and Mörl, 2007; Oliveira et al, 2008). Figures 6 and 7 plot the autocorrelation function and power‐spectra density (PSD) calculated from PF signals recorded at several height for the dry bed (stable system) on the left, and for an unstable system where there was a 4.0 mL/min flow of a 5% sucrose solution on the right.…”

Section: Resultsmentioning

confidence: 99%

“…The appearance of characteristic frequencies in the wet spouted beds can also be seen in Figure 7b for the PSD for the PF signals at positions P 4 , P 5 , and P 6 , reflecting complex phenomena in the wet spouted beds, as depicted in Table 2 and Figure 3. The power spectra for the PF signals at positions P 4 , P 5 , and P 6 , indicate dominant peaks at low frequencies (∼1.0 Hz), characteristic of unstable systems (Oliveira et al, 2008). It can be observed in Figure 7b that the PSD at the P 6 position shows good strength and resolution.…”

Section: Resultsmentioning

confidence: 99%

“…Although time‐series analysis is now used extensively in characterizing flow regimes and fluidization quality, application of these methods to spouted beds is more recent (Wang et al, 2001; Xu et al, 2004a,b,c; Piskova and Mörl, 2007; Oliveira et al, 2008). Although these methods seem to be promising for regime identification, no previous work could be found regarding the use of these techniques to monitor the behaviour of wet spouted beds.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Identification of the state of a wet spouted bed through time‐frequency analysis of pressure fluctuation time series

et al. 2009

Self Cite

View full text Add to dashboard Cite

The feasibility of detecting instability in wet spouted beds via pressure fluctuation (PF) time-series analyses was investigated. Experiments were carried out in a cylindrical Plexiglas column of diameter 150 mm with a conical base of internal angle 60 • , an inlet orifice diameter of 25 mm and glass beads of diameter 2.4 mm. Transducers at several axial positions measured PF time series with incremental addition of aqueous sucrose solutions of different concentrations. Liquid addition affected the spouted bed dynamics, causing irregular spouting, increased voidage in the annulus, increased fountain height, irregular annulus height, channelling, agglomeration, and adhesion of particles to the column walls. Autocorrelations indicated the appearance of periodicities in the PF signals with increasing sucrose addition. Dominant peaks in power-spectral density developed at low frequencies with changing system dynamics. The results indicate that PF signals furnish relevant information on system dynamics, useful for monitoring and control of spouted bed operations such as particle coating and drying of paste-like materials.La faisabilité de déceler l'instabilité dans des lits jaillissants humides par l'analyse de séries chronologiques de fluctuations de pression a été étudiée. Des expériences ont été menées dans une colonne de Plexiglas cylindrique ayant un diamètre de 150 mm et une base conique ayant un angle interne de 60°, un orifice d'entrée d'un diamètre de 25 mm et des billes de verre d'un diamètre de 2,4 mm. Des transducteurs placés à diverses positions axiales mesuraient les séries chronologiques de fluctuations de pression avec ajout incrémentiel de solutions de saccharose aqueux à différentes concentrations. L'ajout de liquide a affecté la dynamique du lit jaillissant, causant un jet irrégulier, une augmentation du degré de vide dans l'espace annulaire, une augmentation de la hauteur de la fontaine, une hauteur irrégulière de l'espace annulaire, un cheminement préférentiel, une agglomération et l'adhésion des particules aux parois de la colonne. Les autocorrélations ont indiqué l'apparition de périodicités dans les signaux FP avec l'ajout additionnel de saccharose. Des pics dominants dans la densité spectrale de puissance sont apparus à basses fréquences avec le changement de la dynamique du système. Les résultats indiquent que les signaux FP donnent des renseignements pertinents sur la dynamique du système, utiles pour le suivi et le contrôle des opérations des lits jaillissants telles que l'enrobage des particules et le séchage de matériaux de type pâte.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Identification of the state of a wet spouted bed through time‐frequency analysis of pressure fluctuation time series

et al. 2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…The changes in the spouted bed flow regimes due to changes in operating conditions for the same experimental system were reported by Oliveira et al (2008). Thus, only a brief summary is provided here.…”

Section: Visual Observation Of Spouted Bed Flow Regimesmentioning

confidence: 69%

“…Different methodologies have been applied for data analysis, including statistical or correlation methods, powerspectral density, and deterministic chaos (He et al, 1997;Bai et al, 1999;Briens, 2000;Van Ommen et al, 1999, 2000Van den Schaaf et al, 2004;Issangya et al, 2000;Wang et al, 2001;Xu et al, 2004a,b,c;Chaplin et al, 2005;Oliveira et al, 2008). Although such measurements are useful, they may present difficulties, including tap penetration of the vessel wall, plugging by particulates, and alteration of the dynamic signal by lines connecting the taps and pressure sensors.…”

mentioning

confidence: 97%

Investigation of acoustic signals as a tool for characterizing spouted bed dynamics

et al. 2009

Self Cite

View full text Add to dashboard Cite

The feasibility of characterizing the dynamics of a spouted bed based on acoustic emission (AE) signals is evaluated. Acoustic emission signals were measured in a semi-cylindrical Plexiglas column of diameter 150 mm and height 1000 mm with a conical base of internal angle 60 • and 25 mm inlet orifice diameter. Data were obtained for U/U ms from 0.3 to 2.0, static bed height from 250 to 500 mm, and glass beads of diameter 1.2 and 2.4 mm. AE signals reflected the effects of particle size and U/U ms , but in general were insensitive to bed depth, even when there were drastic changes in spouting flow patterns. The results indicate that the AE signals were insensitive to the spouted bed hydrodynamics for the conditions studied. Overall, it appears that the AE analysis is unlikely to be a suitable technique for discriminating spouted bed flow regimes, at least for the range of frequencies and operating conditions investigated.Onévalue ici la faisabilité de caractériser la dynamique d'un lit jaillissant en se basant sur les signaux d'émission acoustique (AE). Les signaux d'émission acoustique ontété mesurés dans une colonne de Plexiglas semi-cylindrique ayant un diamètre de 150 mm et une hauteur de 1000 mm, et une base conique ayant un angle interne de 60 • et un orifice d'entrée d'un diamètre de 25 mm. Des données ontété obtenues pour les U/U ms de 0,3à 2,0, une hauteur de lit statique de 250à 500 mm, et des billes de verre d'un diamètre de 1,2 et 2,4 mm. Les signaux AE reflétaient les effets de la taille des particules et des U/U ms , mais règle générale demeuraient insensiblesà la profondeur du lit, même en présence de changements radicaux des modèles d'écoulement du jaillissement. Les résultats indiquent que les signaux AEétaient insensiblesà l'hydrodynamique du lit jaillissant dans les conditionsà l'étude. Dans l'ensemble, il ressort que l'analyse des signaux d'émission acoustique n'est pas susceptible d'étre une technique adéquate de discrimination des régimes d'écoulement des lits jaillissants, du moins dans l'éventail des fréquences et des conditions de fonctionnementétudiées.

show abstract

Characterization and Development of Geldart’s Fluidizing Velocity Profile of Sand Particles for the Application in Fluidized Bed Combustor (FBC)

Shukrie

Anuar

Alias

2016

Regional Conference on Science, Technology and Social Sciences (RCSTSS 2014)

View full text Add to dashboard Cite

Evaluation of flow regimes in a semi‐cylindrical spouted bed through statistical, mutual information, spectral and Hurst's analysis

Cited by 17 publications

References 38 publications

Identification of the state of a wet spouted bed through time‐frequency analysis of pressure fluctuation time series

Identification of the state of a wet spouted bed through time‐frequency analysis of pressure fluctuation time series

Investigation of acoustic signals as a tool for characterizing spouted bed dynamics

Characterization and Development of Geldart’s Fluidizing Velocity Profile of Sand Particles for the Application in Fluidized Bed Combustor (FBC)

Contact Info

Product

Resources

About