Electrical Capacitance Volume Tomography

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Abstract: A dynamic volume imaging based on the principle of electrical capacitance tomography (ECT), namely, electrical capacitance volume tomography (ECVT), has been developed in this study. The technique generates, from the measured capacitance, a whole volumetric image of the region enclosed by the geometrically three-dimensional capacitance sensor. This development enables a real-time, 3-D imaging of a moving object or a real-time volume imaging (4-D) to be realized. Moreover, it allows total interrogation of the whole volume within the domain (vessel or…

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A Multimodal Tomography System Based on ECT Sensors

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Abstract: A new noninvasive system for multimodal electrical tomography based on electrical capacitance tomography (ECT) sensor hardware is proposed. Quasistatic electromagnetic fields are produced by ECT sensors and used for interrogating the sensing domain. The new system is noninvasive and based on capacitance measurements for permittivity and power balance measurements for conductivity (impedance) imaging. A dual sensitivity map of perturbations in permittivity and conductivity is constructed. The measured data along with the sensitivity matrix are used for the actual image reconstruction….

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Adaptive Electrical Capacitance Volume Tomography

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Abstract—Electrical Capacitance Volume Tomography (ECVT) has shown to be an effective low-cost and high-speed imaging technique suitable for many applications, including 3D reconstruction of multiphase flow systems. In this paper, we introduce the concept of adaptive ECVT based upon the combination of a large number of small individual sensor segments to comprise synthetic capacitance “plates” of different (and possibly noncontiguous) shapes while still satisfying a minimum plate area criterion set by a given SNR. The response from different segments is…

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Electrical capacitance volume tomography for imaging of pulsating flows in a trickle bed

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Abstract: Experimental results of the air–water pulsating flows in a trickle bed column were obtained using the electrical capacitance volume tomography (ECVT) system. Detailed 3-D pulse structures in both the fully developed and the transient conditions were illustrated. Pulse frequency, pulse traveling velocity, average liquid holdup and liquid holdup inside the gas-rich and liquid-rich regions, respectively, were measured. Based on a simplified model, the linear liquid velocities inside the gas-rich and liquid-rich regions were estimated. The results revealed that the…

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ECVT IMAGING OF 3-D FLOW STRUCTURES AND SOLIDS CONCENTRATION DISTRIBUTIONS IN A RISER AND A BEND OF A GAS-SOLID CIRCULATING FLUIDIZED BED

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Abstract: Electrical Capacitance Volume Tomography (ECVT) is a newly developed imaging technique that can quantify 3-D multiphase flows in a complex, geometric flow field. In this study, the 3-D phase distribution images inside a gas-solid circulating fluidized bed (CFB) are obtained using the ECVT. Specifically, measurements are made at a riser section and a 90o bendshape riser exit section of the CFB. Inside the vertical riser, a symmetric core-annulus structure with a low solids holdup in the riser center along…

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Bubbling fluidized bed characterization using Electrical Capacitance Volume Tomography (ECVT)

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Abstract: Understanding the fundamentals of gas–solid fluidized beds and, in general, multiphase flows has been a significant task since the conception of gas–solid fluidization and fluid particle systems. Various measurement techniques have been applied in an attempt to better understand the fundamentals of the complex gas–solid flow structures that form in fluidized beds. This information may potentially provide a better design, scale-up, and operation of these systems as well as lead to accurate performance predictions of multiphase flow systems. Electrical…

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Electrical Capacitance Volume Tomography: Design and Applications

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Abstract: This article reports recent advances and progress in the field of electrical capacitance volume tomography (ECVT). ECVT, developed from the two-dimensional electrical capacitance tomography (ECT), is a promising non-intrusive imaging technology that can provide real-time three-dimensional images of the sensing domain. Images are reconstructed from capacitance measurements acquired by electrodes placed on the outside boundary of the testing vessel. In this article, a review of progress on capacitance sensor design and applications to multi-phase flows is presented. The sensor…

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Novel Sensor Provides Insight to Flow of Solids

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View the original Department of Energy article. Published in netlognews, NETL’s R&D newletter, October 2012, issue 27 Novel Sensor Provides Insight to Flow of Solids Our researchers are applying Electrical Capacitance Volume Tomography (ECVT), developed by Tech4Imaging, to quantify solids concentration and bubble dynamics in a fluidized bed. The ECVT sensors allow for a non-intrusive, three-dimensional measurement of solids concentrations in gas-solid, gas-liquid, and liquid-solid multiphase flow systems. Certain behaviors of fluidized beds, such as solids concentration distribution, bubble diameter,…

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Bubbling Fluidized Bed Characterization Using Electrical Capacitance Volume Tomography (ECVT)

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This article was published in Science Direct, Volume 242, July 2013, Pages 40–50 Selected Papers from the 2010 NETL Multiphase Flow Workshop DOI: 10.1016/j.powtec.2013.01.044 Publication Date (Web): 26 January 2013 Abstract: Understanding the fundamentals of gas–solid fluidized beds and, in general, multiphase flows has been a significant task since the conception of gas–solid fluidization and fluid particle systems. Various measurement techniques have been applied in an attempt to better understand the fundamentals of the complex gas–solid flow structures that form…

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