A novel calibration procedure for a fiber optic solids concentration probe

Zhang, H.; Johnston, P.M.; Zhu, Jesse; Lasa, Hugo I. de; Bergougnou, M.A.

doi:10.1016/s0032-5910(98)00147-8

Cited by 172 publications

(100 citation statements)

References 11 publications

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“…This combination of the sampling rate and sampling length ensured that the full spectra of hydrodynamic signals of interest were captured from the fluidized bed. Using a calibration equation the voltage data were converted to solids concentrations and the calibration process was described in detail by Zhang et al 25 Since the reflective optical fiber probe was an intrusive measurement technique, the impacts of the two probes on the overall flow structure were tested under four operating conditions, listed in Table 2 the solids concentration was measured five times with just probe no. 1 at 10 radial positions.…”

Section: Methodsmentioning

confidence: 99%

Gas‐solids flow structures in a novel circulating‐turbulent fluidized bed

He-hua

Zhu

2008

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com).In this article a novel circulating-turbulent fluidized bed (C-TFB) featured by high solids holdup and high gross solids circulation has been introduced and tested. The purpose of the new design was to integrate conventional circulating and turbulent fluidized beds into a unique high-density fluidization system for more efficient gas-solid contact and significantly reduced solids backmixing. The hydrodynamic characteristics of the C-TFB were analyzed in terms of differential pressure, solids concentration, particle velocity, and local solids flux distributions. An axial homogeneous flow structure was easily obtained with cross-sectional average solids volume concentrations higher than 0.25 throughout the entire C-TFB. At all measuring positions there was no net downflow of solids and a good gas-solid mixing was observed.

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Section: Methodsmentioning

confidence: 99%

Gas‐solids flow structures in a novel circulating‐turbulent fluidized bed

He-hua

Zhu

2008

AIChE Journal

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“…The dimensions of the probe are shown in Figure 3. A calibration procedure proposed by Zhang et al 27 was carried out. The calibration apparatus which mainly consisted of a controllable solids feeding system, a 16.6 mm-i.d.30.4 m-long test pipe and a shutter valve, as shown in Figure 4, was used.…”

Section: Calibration Of Fiber Optic Probementioning

confidence: 99%

Multiresolution analysis on identification and dynamics of clusters in a circulating fluidized bed

Yang

Leu

2009

AIChE Journal

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). An appropriate level of approximation subsignal was systematically specified as a threshold for cluster identification, based on multiresolution analysis (MRA) of wavelet transformation. By the established threshold, the dynamic properties of clusters including the appearance time fraction of clusters F cl , average cluster duration time s cl , cluster frequency f cl , and local average solids holdup in clusters e sc , at different radial and axial positions were determined under the turbulent, transition and fast fluidization flow regimes. The results also describe the dynamic properties of clusters and flow patterns in the splash zone along with the dense bottom region of the circulating fluidized beds.

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“…During the past, a large research effort has been directed towards developing measurement techniques aimed to get knowledge on the dynamic phenomena that take place within the bed (Werther, 1999;Yates and Simons, 1994); some examples are the capacity and the inductance measurements (Brereton and Grace, 1993;Louge and Opie, 1990), techniques based on optic fiber probes (Amos et al, 1996;Zhang et al, 1998), and laser based measurements (Briongos and Guardiola, 2003;Solimene et al, 2007). However, among those techniques, the pressure fluctuations measurements remain as the most used technique (Johnsson et al, 2000;Sasic et al, 2007).…”

Section: Introductionmentioning

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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A novel calibration procedure for a fiber optic solids concentration probe

Cited by 172 publications

References 11 publications

Gas‐solids flow structures in a novel circulating‐turbulent fluidized bed

Gas‐solids flow structures in a novel circulating‐turbulent fluidized bed

Multiresolution analysis on identification and dynamics of clusters in a circulating fluidized bed

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

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