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Agglomeration detection in horizontal stirred bed reactor based on autoregression model by acoustic emission signals / Yefeng Zhou in Industrial & engineering chemistry research, Vol. 51 N° 36 (Septembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11629-11635 Titre : Agglomeration detection in horizontal stirred bed reactor based on autoregression model by acoustic emission signals Type de document : texte imprimé Auteurs : Yefeng Zhou, Auteur ; Zhengliang Huang, Auteur ; Ren Congjing, Auteur Année de publication : 2012 Article en page(s) : pp. 11629-11635 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Acoustic  emission  Modeling  Stirred  tank  reactor  Agglomeration Résumé : Agglomeration occurring in horizontal stirred bed reactors (HSBR) for polyolefin production has negative impacts on the efficiency of the reactor operation and may sometimes lead to unscheduled shutdown of the plant. In this paper, an autoregression (AR) model based on acoustic emission (AE) technique has been proposed to establish the qualitative relationship between AE signals and agglomeration in the HSBR. In this method, the frequency of AE signal varies with particles of different sizes striking the reactor walls. From the cold model experiments, it was found that AR power spectrum became fluctuant after the addition of agglomerations into laboratorial scale HSBR, and meanwhile the low frequency band energy ratio and the variance of AE signals kept rising. Furthermore, this AE-based AR model was also successfully applied to detect the agglomeration in an industrial HSBR unit, showing that the method could monitor agglomerations in an environmentally friendly manner and with fairly good accuracy. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26350328 [article] Agglomeration detection in horizontal stirred bed reactor based on autoregression model by acoustic emission signals [texte imprimé] / Yefeng Zhou, Auteur ; Zhengliang Huang, Auteur ; Ren Congjing, Auteur . - 2012 . - pp. 11629-11635. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11629-11635 Mots-clés : Acoustic  emission  Modeling  Stirred  tank  reactor  Agglomeration Résumé : Agglomeration occurring in horizontal stirred bed reactors (HSBR) for polyolefin production has negative impacts on the efficiency of the reactor operation and may sometimes lead to unscheduled shutdown of the plant. In this paper, an autoregression (AR) model based on acoustic emission (AE) technique has been proposed to establish the qualitative relationship between AE signals and agglomeration in the HSBR. In this method, the frequency of AE signal varies with particles of different sizes striking the reactor walls. From the cold model experiments, it was found that AR power spectrum became fluctuant after the addition of agglomerations into laboratorial scale HSBR, and meanwhile the low frequency band energy ratio and the variance of AE signals kept rising. Furthermore, this AE-based AR model was also successfully applied to detect the agglomeration in an industrial HSBR unit, showing that the method could monitor agglomerations in an environmentally friendly manner and with fairly good accuracy. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26350328

Characterization of particle fluidization pattern in a gas solid fluidized bed based on acoustic emission (AE) measurement / Wang Jingdai in Industrial & engineering chemistry research, Vol. 48 N° 18 (Septembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8508–8514 Titre : Characterization of particle fluidization pattern in a gas solid fluidized bed based on acoustic emission (AE) measurement Type de document : texte imprimé Auteurs : Wang Jingdai, Auteur ; Ren Congjing, Auteur ; Yongrong Yang, Auteur Année de publication : 2010 Article en page(s) : pp. 8508–8514 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Fluidized  bed  Acoustic  emission  measurement Résumé : Flow pattern of the fluidized bed is a key factor for heat transfer and the design of a new reactor. It is important to comprehend the fluidization conditions because the complex correlation between particle−particle and particle−environment in the reactor. In this study, we applied acoustic emission (AE) measurement in monitoring the particle fluidization pattern in a gas−solid bed fluidized with different sorts of particles classified by Geldart. With AE axial time average energy analysis, the flow structure of polyethylene particles was investigated both in the laboratory and plant apparatus. The results showed that the fluidization pattern in the bed is multicirculation, including the main-circulation zone, subcirculation zone, and the stagnant zone. Moreover, the influence of operating variables, such as particle size, superficial gas velocity, static bed height, and particle sorts had also been considered. It was found that the particle size, gas velocity, and particle sorts have significant impacts to the fluidization pattern. In contrast, the height of the stagnant zone did not show direct relation to the static bed height. AE measurement was proved to be reliable for understanding the dynamical features that affect the behavior of the fluidized bed. This can be useful guidance for an industrial process and help improve the process operation and the design of the new reactor. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8018774 [article] Characterization of particle fluidization pattern in a gas solid fluidized bed based on acoustic emission (AE) measurement [texte imprimé] / Wang Jingdai, Auteur ; Ren Congjing, Auteur ; Yongrong Yang, Auteur . - 2010 . - pp. 8508–8514. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8508–8514 Mots-clés : Fluidized  bed  Acoustic  emission  measurement Résumé : Flow pattern of the fluidized bed is a key factor for heat transfer and the design of a new reactor. It is important to comprehend the fluidization conditions because the complex correlation between particle−particle and particle−environment in the reactor. In this study, we applied acoustic emission (AE) measurement in monitoring the particle fluidization pattern in a gas−solid bed fluidized with different sorts of particles classified by Geldart. With AE axial time average energy analysis, the flow structure of polyethylene particles was investigated both in the laboratory and plant apparatus. The results showed that the fluidization pattern in the bed is multicirculation, including the main-circulation zone, subcirculation zone, and the stagnant zone. Moreover, the influence of operating variables, such as particle size, superficial gas velocity, static bed height, and particle sorts had also been considered. It was found that the particle size, gas velocity, and particle sorts have significant impacts to the fluidization pattern. In contrast, the height of the stagnant zone did not show direct relation to the static bed height. AE measurement was proved to be reliable for understanding the dynamical features that affect the behavior of the fluidized bed. This can be useful guidance for an industrial process and help improve the process operation and the design of the new reactor. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8018774

Characterization of particle fluidization pattern in a gas solid fluidized bed based on acoustic emission (AE) measurement / Wang Jingdai in Industrial & engineering chemistry research, Vol. 48 N° 18 (Septembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8508–8514 Titre : Characterization of particle fluidization pattern in a gas solid fluidized bed based on acoustic emission (AE) measurement Type de document : texte imprimé Auteurs : Wang Jingdai, Auteur ; Ren Congjing, Auteur ; Yongrong Yang, Auteur Année de publication : 2010 Article en page(s) : pp. 8508–8514 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Fluidized  bed  Acoustic  emission  measurement Résumé : Flow pattern of the fluidized bed is a key factor for heat transfer and the design of a new reactor. It is important to comprehend the fluidization conditions because the complex correlation between particle−particle and particle−environment in the reactor. In this study, we applied acoustic emission (AE) measurement in monitoring the particle fluidization pattern in a gas−solid bed fluidized with different sorts of particles classified by Geldart. With AE axial time average energy analysis, the flow structure of polyethylene particles was investigated both in the laboratory and plant apparatus. The results showed that the fluidization pattern in the bed is multicirculation, including the main-circulation zone, subcirculation zone, and the stagnant zone. Moreover, the influence of operating variables, such as particle size, superficial gas velocity, static bed height, and particle sorts had also been considered. It was found that the particle size, gas velocity, and particle sorts have significant impacts to the fluidization pattern. In contrast, the height of the stagnant zone did not show direct relation to the static bed height. AE measurement was proved to be reliable for understanding the dynamical features that affect the behavior of the fluidized bed. This can be useful guidance for an industrial process and help improve the process operation and the design of the new reactor. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8018774 [article] Characterization of particle fluidization pattern in a gas solid fluidized bed based on acoustic emission (AE) measurement [texte imprimé] / Wang Jingdai, Auteur ; Ren Congjing, Auteur ; Yongrong Yang, Auteur . - 2010 . - pp. 8508–8514. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8508–8514 Mots-clés : Fluidized  bed  Acoustic  emission  measurement Résumé : Flow pattern of the fluidized bed is a key factor for heat transfer and the design of a new reactor. It is important to comprehend the fluidization conditions because the complex correlation between particle−particle and particle−environment in the reactor. In this study, we applied acoustic emission (AE) measurement in monitoring the particle fluidization pattern in a gas−solid bed fluidized with different sorts of particles classified by Geldart. With AE axial time average energy analysis, the flow structure of polyethylene particles was investigated both in the laboratory and plant apparatus. The results showed that the fluidization pattern in the bed is multicirculation, including the main-circulation zone, subcirculation zone, and the stagnant zone. Moreover, the influence of operating variables, such as particle size, superficial gas velocity, static bed height, and particle sorts had also been considered. It was found that the particle size, gas velocity, and particle sorts have significant impacts to the fluidization pattern. In contrast, the height of the stagnant zone did not show direct relation to the static bed height. AE measurement was proved to be reliable for understanding the dynamical features that affect the behavior of the fluidized bed. This can be useful guidance for an industrial process and help improve the process operation and the design of the new reactor. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8018774

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

Online estimation of coke in a circulating fluidized bed based on acoustic emission sensors and multivariate calibration / Ren Congjing in Industrial & engineering chemistry research, Vol. 50 N° 14 (Juillet 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 14 (Juillet 2011) . - pp. 8420-8429 Titre : Online estimation of coke in a circulating fluidized bed based on acoustic emission sensors and multivariate calibration Type de document : texte imprimé Auteurs : Ren Congjing, Auteur ; Tang Yueqi, Auteur ; Wang Jingdai, Auteur Année de publication : 2011 Article en page(s) : pp. 8420-8429 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Calibration  Acoustic  emission  Circulating  fluidized  bed  Fluidization Résumé : The aim of this work was to investigate the application of an acoustic monitoring system for production scale circulating fluidized bed processes. The relationship between acoustic signals and the coke amount deposited on the catalysts was investigated on both lab scale and production scale reactors. By using Power spectrum density analysis, the relationship between the coke amount and the frequency shift of the characteristic peak of acoustic signals was found to be linear. In addition, a model to detect the coke amount on catalyst was established based on partial least-squares regression. Comparing the model results with experimental data, the amount of deposited coke is determined with a correlation coefficient 0.947 and a root mean squares error of cross validation 0.948%, which means that this model is accurate and capable of monitoring the coke amount on catalyst. Furthermore, the results of the preliminary industrial tests are considered to be promising. This work provides valuable insights into the online monitoring of coke amounts in circulating fluidized beds based on an AE technique. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24346882 [article] Online estimation of coke in a circulating fluidized bed based on acoustic emission sensors and multivariate calibration [texte imprimé] / Ren Congjing, Auteur ; Tang Yueqi, Auteur ; Wang Jingdai, Auteur . - 2011 . - pp. 8420-8429. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 14 (Juillet 2011) . - pp. 8420-8429 Mots-clés : Calibration  Acoustic  emission  Circulating  fluidized  bed  Fluidization Résumé : The aim of this work was to investigate the application of an acoustic monitoring system for production scale circulating fluidized bed processes. The relationship between acoustic signals and the coke amount deposited on the catalysts was investigated on both lab scale and production scale reactors. By using Power spectrum density analysis, the relationship between the coke amount and the frequency shift of the characteristic peak of acoustic signals was found to be linear. In addition, a model to detect the coke amount on catalyst was established based on partial least-squares regression. Comparing the model results with experimental data, the amount of deposited coke is determined with a correlation coefficient 0.947 and a root mean squares error of cross validation 0.948%, which means that this model is accurate and capable of monitoring the coke amount on catalyst. Furthermore, the results of the preliminary industrial tests are considered to be promising. This work provides valuable insights into the online monitoring of coke amounts in circulating fluidized beds based on an AE technique. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24346882