Non-intrusive monitoring of bubbles in a gas–solid fluidized bed using vibration signature analysis

Abbasi, Mojgan; Sotudeh‐Gharebagh, Rahmat; Mostoufi, Navid; Mahjoob, M. J.

doi:10.1016/j.powtec.2009.08.012

Cited by 61 publications

(41 citation statements)

References 15 publications

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“…To conclude with the validation of the vibration induced by the pulse-type excitation test, figure 8 compares the results reported in Abbasi et al (2009). For the different fluidization conditions, the resulting PSD functions from the simulation runs exhibited a characteristic frequency peak close to the 1 kHz value (peak number one), which characterizes the measured spectra.…”

Section: Vibration Induced By Pulse-type Excitationmentioning

confidence: 75%

“…In addition, this approach disregards two important factors, such as the compression waves (van der Schaaf et al, 1998) and the structural vessel dynamics, which might affect the measurement of flow-induced vibration resulting from the fluidized bed dynamics, as discussed below. Consequently, the use of a theory based solely on "elastic waves" as the single source of "Acoustic Emissions ( AE)" cannot be easily extended to other FB systems and does not explain the most recent research results in the field (Abbasi et al, 2009;Cody et al, 1996;Cody et al, 2000;de Martin et al, 2010;de Martin et al, 2011;Li et al, 2011).…”

Section: Flow-induced Vibration In Fluidized Bedsmentioning

confidence: 99%

“…One of the main drawbacks of this approach results from the high computational cost of sampling at those high frequencies, as the great number of data in each sample complicates the measurement process, limiting the number of time series analysis techniques that can be used to handle the data. A more commercial low-cost measurement approach has been developed that uses sampling frequencies that are considerably reduced in the measurement ranges between 20 kHz to 50 kHz (Abbasi et al, 2010;Abbasi et al, 2009;Cody et al, 1996;Cody et al, 2008). With this low frequency approach, two very different interpretations of the measured accelerometer signals are used to understand the flow-dynamic information of the FB system.…”

Section: Introductionmentioning

confidence: 99%

“…In (Cody et al, 1996), the measured mechanical vibrations were also attributed to random particle impact. In contrast, (Abbasi et al, 2009) used the accelerometer measured signal to study bubble dynamics, assuming that the vibration signal recorded by the accelerometers "directly reflects the bubble characteristics". For the accelerometer signal collected at high or low frequencies, the results reported in the literature suggest that these AE methods can be useful in extracting information on the fluidized bed dynamics.…”

Section: Introductionmentioning

confidence: 99%

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Characterization of flow-induced vibrations in gas–solid fluidized beds: Elements of the theory

Briongos

Sobrino

Gómez-Hernández

et al. 2013

Chemical Engineering Science

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Abstract:This paper revisits the basic hypothesis underlying the measurement of flow-induced vibration in fluidized beds. A novel theoretical approach based on the standing pressure field characterizing the bed dynamics is proposed to link the pressure fluctuations to the measured accelerometer signals. The model provides a reliable prediction of the carrying frequency band and helps in designing the accelerometer measurement process.The model was tested with previous results reported in the literature as well as with piezoelectric accelerometer measurements collected from a lab-scale experimental facility. A study on accelerometer measurements was conducted to identify the main limitations expected for measuring flow-induced vibrations in a gas-solid fluidized bed.The structural response of the vessel to flow-induced vibration was mostly determined by the "bed acoustics" that can be dominated by either elastic or compression waves.Finally, the survival of an envelope process on the measured accelerometer signal guaranteed the quality of the flow dynamical information collected during the measurement process.

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Section: Vibration Induced By Pulse-type Excitationmentioning

confidence: 75%

Section: Flow-induced Vibration In Fluidized Bedsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Characterization of flow-induced vibrations in gas–solid fluidized beds: Elements of the theory

Briongos

Sobrino

Gómez-Hernández

et al. 2013

Chemical Engineering Science

View full text Add to dashboard Cite

show abstract

“…That fact leads to the use of different techniques focused on identifying and distin guishing those contributions from the measured signal. Thus, the multi scale nature of fluidized bed dynamics has drawn con siderable attention in the last years (Li and Kwauk, 2001;Lu and Li, 1999;Zhao and Yang, 2003;Briongos et al, 2006aBriongos et al, , 2007Abbasi et al, 2009). However, due that the causes and sources of accelerometer signals are not yet understood, the Coherent Output Power, COP, and the Incoherent Output Power, IOP, analysis used in van der Schaaf et al (2002) is applied here as a first approach to analyze the different dynamical components appearing in the envelope process, comparing the local and global information stored in both pressure and envelope accelerometer signals.…”

Section: Frequency Domainmentioning

confidence: 99%

Can low frequency accelerometry replace pressure measurements for monitoring gas-solid fluidized beds?

Martín

Briongos

Aragón

et al. 2010

Chemical Engineering Science

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a b s t r a c tThis paper is addressed to introduce a methodology based on low frequency accelerometry that can be used for gas solid fluidized bed monitoring, and for dynamic diagnosis purposes. The proposed methodology consists on extracting the low frequency information encoded within an accelerometry signal, by means of the Hilbert transform method. The time and the frequency domain analysis show how this low frequency information is directly related to the conventional pressure fluctuation measurements, providing useful information on bulk and bubble dynamics. The cross correlation and the coherence function analysis between the pressure and the envelope process of the measured accelerometer signals ''E'', exhibit values approaching unity for frequencies ranging between 2 and 4 Hz. This reveals that pressure signals and accelerometry envelope are related processes. The results from the Coherent Output Power, COP, and the Incoherent Output Power, IOP, analysis confirms that both pressure and envelope time series exhibit the same global and local features open the possibility of using low frequency accelerometers instead of conventional pressure transducers for monitoring and for dynamic diagnosis purposes.

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Characterization on hydrodynamic behavior in liquid‐containing gas‐solid fluidized bed reactor

et al. 2012

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in Wiley Online Library (wileyonlinelibrary.com).In many industrial processes involving gas-solid fluidized bed rectors, the addition of a liquid phase significantly alters the hydrodynamics. To fully characterize the hydrodynamics in the fluidized bed, pressure and acoustic measuring techniques were applied to study the behavior of gas bubbles and particles. A camera was used to take pictures to verify the pressure and acoustic results. During the liquid-addition process, the pressure technique captured the bubble size variation and bubble motion while the acoustic technique reflected particle motion and particle size growth. Hurst and V-statistics analyses of acoustic emission were used for the first time to detect periodic behavior during the injection process. The new break formation and change trend of V max were used as the criteria to judge occurrence of abnormal fluidization states, such as agglomeration and gas channeling formation. These measurement techniques are beneficial in the elimination of adverse effects caused by the addition of liquid.

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Non-intrusive monitoring of bubbles in a gas–solid fluidized bed using vibration signature analysis

Cited by 61 publications

References 15 publications

Characterization of flow-induced vibrations in gas–solid fluidized beds: Elements of the theory

Characterization of flow-induced vibrations in gas–solid fluidized beds: Elements of the theory

Can low frequency accelerometry replace pressure measurements for monitoring gas-solid fluidized beds?

Characterization on hydrodynamic behavior in liquid‐containing gas‐solid fluidized bed reactor

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