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Agglomeration detection by acoustic emission (AE) sensors in fluidized beds / Wang Jingdai in Industrial & engineering chemistry research, Vol. 48 N° 7 (Avril 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 7 (Avril 2009) . - pp. 3466–3473 Titre : Agglomeration detection by acoustic emission (AE) sensors in fluidized beds Type de document : texte imprimé Auteurs : Wang Jingdai, Auteur ; Yijia Cao, Auteur ; Xiaojing Jiang, Auteur Année de publication : 2009 Article en page(s) : pp. 3466–3473 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Fluidized  beds  Polyolefin  Acoustic  emission  sensors  Chaos  analysis Résumé : The occurrence of agglomeration in fluidized-bed production of polyolefin can have negative impacts on the efficiency of the reactor operation and may lead to defluidization and unscheduled shutdown of the plant. A novel method by using acoustic emission (AE) sensors was developed to detect different types of agglomeration in fluidized bed. Chaos analysis was discussed, and coefficients of malfunction were defined to recognize agglomeration. AE signals we divided into micro-, meso-, and macroscales by wavelet transform, and on the basis of the energy of mesoscale fraction analysis of AE signals, a prediction model was developed to predict the size of moving chunks in the bed. The application effect of AE method was illustrated with experiments carried out both in laboratory and the plant. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800324m [article] Agglomeration detection by acoustic emission (AE) sensors in fluidized beds [texte imprimé] / Wang Jingdai, Auteur ; Yijia Cao, Auteur ; Xiaojing Jiang, Auteur . - 2009 . - pp. 3466–3473. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 7 (Avril 2009) . - pp. 3466–3473 Mots-clés : Fluidized  beds  Polyolefin  Acoustic  emission  sensors  Chaos  analysis Résumé : The occurrence of agglomeration in fluidized-bed production of polyolefin can have negative impacts on the efficiency of the reactor operation and may lead to defluidization and unscheduled shutdown of the plant. A novel method by using acoustic emission (AE) sensors was developed to detect different types of agglomeration in fluidized bed. Chaos analysis was discussed, and coefficients of malfunction were defined to recognize agglomeration. AE signals we divided into micro-, meso-, and macroscales by wavelet transform, and on the basis of the energy of mesoscale fraction analysis of AE signals, a prediction model was developed to predict the size of moving chunks in the bed. The application effect of AE method was illustrated with experiments carried out both in laboratory and the plant. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800324m

Determination of critical speed for complete solid suspension using acoustic emission method based on multiscale analysis in stirred tank / Ren Congjing in Industrial & engineering chemistry research, Vol. 47 n°15 (Août 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5323–5327 Titre : Determination of critical speed for complete solid suspension using acoustic emission method based on multiscale analysis in stirred tank Type de document : texte imprimé Auteurs : Ren Congjing, Auteur ; Xiaojing Jiang, Auteur ; Wang Jingdai, Auteur ; Yongrong Yang, Auteur Année de publication : 2008 Article en page(s) : p. 5323–5327 Note générale : Bibliogr. p. 5327 Langues : Anglais (eng) Mots-clés : Solid  suspension;  Acoustic  emission;  Stirred  tank;  Multiscale  analysis Résumé : According to the mechanism that acoustic emission (AE) signals with different frequency ranges were emitted when solid particles impacted the wall, a characteristic scale (S1) of the AE signals representing the movement of solid particles was obtained by using wavelet transform and Hurst analysis. A regular evolution behavior of energy fraction on each frequency with the increasing impeller speeds was observed. A new method to determine critical impeller speed was presented by analyzing the relationship between energy fraction in S1 scale and the impeller speed. The critical impeller speed was associated with the emergence of steady state in energy fractions in the S1 scale. The method was further verified with four groups of experiments with the particle sizes of 0.5 mm and 0.7 mm by comparing experimental results with that from the conventional visual method for a water and glass beads system. The average relative errors were no more than 4.28%. It is a fast, nonintrusive, and accurate method to investigate the Njs by multiscale analysis of acoustic energy. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0714347 [article] Determination of critical speed for complete solid suspension using acoustic emission method based on multiscale analysis in stirred tank [texte imprimé] / Ren Congjing, Auteur ; Xiaojing Jiang, Auteur ; Wang Jingdai, Auteur ; Yongrong Yang, Auteur . - 2008 . - p. 5323–5327. Bibliogr. p. 5327 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5323–5327 Mots-clés : Solid  suspension;  Acoustic  emission;  Stirred  tank;  Multiscale  analysis Résumé : According to the mechanism that acoustic emission (AE) signals with different frequency ranges were emitted when solid particles impacted the wall, a characteristic scale (S1) of the AE signals representing the movement of solid particles was obtained by using wavelet transform and Hurst analysis. A regular evolution behavior of energy fraction on each frequency with the increasing impeller speeds was observed. A new method to determine critical impeller speed was presented by analyzing the relationship between energy fraction in S1 scale and the impeller speed. The critical impeller speed was associated with the emergence of steady state in energy fractions in the S1 scale. The method was further verified with four groups of experiments with the particle sizes of 0.5 mm and 0.7 mm by comparing experimental results with that from the conventional visual method for a water and glass beads system. The average relative errors were no more than 4.28%. It is a fast, nonintrusive, and accurate method to investigate the Njs by multiscale analysis of acoustic energy. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0714347