Visualisation of Two-Phase Gas-Liquid Pipe Flows Using Electrical Capacitance Tomography

Volume 1 ◽  
2004 ◽  
Author(s):  
Andy Hunt ◽  
John Pendleton ◽  
Yves Ladam
Keyword(s):  
Velocity Distribution ◽  
Virtual Instrument ◽  
Gamma Ray ◽  
Electrical Capacitance Tomography ◽  
Electrical Capacitance ◽  
Flow Loop ◽  
Two Phase ◽  
Cross Sectional ◽  
Measure Concentration ◽  
Capacitance Tomography

Electrical Capacitance Tomography (ECT) has been used over a number of years to measure concentration distribution, and more recently velocity distribution, in two-phase flows. ECT is non-intrusive, and the reconstruction of the concentration and velocity distribution can be undertaken in real time and over an arbitrary number of zones in the flow cross-section. In this paper the concept of a ‘virtual instrument’ is introduced where zones of the image can be structured for comparison with other measurements. Numerical agreement with gamma-ray density measurements is shown to be excellent in slug and stratified flows. We present a series of measurements undertaken in complex oil/gas slug flows in a large flow loop. We present a variety of 2-D cross-sectional images, time series velocity and concentration graphs and 3-D contour plots. The good temporal and spatial resolution of ECT throws an extensive new light on these otherwise difficult to measure dynamic flow structures. In particular with bubbly-slug structures known as ‘ghosts’ ECT shows clearly that they are in fact bubbly waves which have extended ‘wings’ up and around the pipe.

Image Fusion of ECT/ERT for Oil-Gas-Water Three-Phase Flow

2011 ◽  
Vol 3 (2) ◽  
pp. 29-34 ◽  
Author(s):  
Lifeng Zhang
Keyword(s):  
Image Fusion ◽  
Electrical Capacitance Tomography ◽  
Phase Flow ◽  
Electrical Capacitance ◽  
Cross Sectional ◽  
Three Phase ◽  
Three Phase Flow ◽  
Capacitance Tomography ◽  
Oil Gas ◽  
Image Fusion Method

The tomographic imaging of process parameters for oil-gas-water three-phase flow can be obtained through different sensing modalities, such as electrical resistance tomography (ERT) and electrical capacitance tomography (ECT), both of which are sensitive to specific properties of the objects to be imaged. However, it is hard to discriminate oil, gas and water phases merely from reconstructed images of ERT or ECT. In this paper, the feasibility of image fusion based on ERT and ECT reconstructed images was investigated for oil-gas-water three-phase flow. Two cases were discussed and pixel-based image fusion method was presented. Simulation results showed that the cross-sectional reconstruction images of oil-gas-water three-phase flow can be obtained using the presented methods.

Electrical Capacitance Tomography Based Sorting Technique for Wasted Plastics

2015 ◽  
Author(s):  
Yusuke Hirose ◽  
Kazuaki Hata ◽  
Sapkota Achyut ◽  
Masahiro Takei
Keyword(s):  
Temperature Distribution ◽  
Relative Permittivity ◽  
Electrical Capacitance Tomography ◽  
Electrical Capacitance ◽  
Time Step ◽  
Cross Sectional ◽  
Sorting Technique ◽  
The Many ◽  
Capacitance Tomography ◽  
Temperature Equation

This study has launched a concept to measure real time two-dimensional temperature distribution non-invasively by a combination of electrical capacitance tomography (ECT) technique and a permittivity-temperature equation for plastic pellets. The concept has two steps which are the relative permittivity calculation from the measured capacitance among the many electrodes by ECT technique, and the temperature distribution calculation from the relative permittivity distribution by permittivity-temperature equation. ECT sensor with 12-electrode is designed to measure and visualize the cross sectional temperature distribution during polymethyl methacrylate (PMMA) pellets cooling process. The images of the normalized relative permittivity distribution are successfully reconstructed at every time step during the process. The images indicate that the normalized relative permittivity of PMMA pellets is decreased as the temperature is decreased.

scholarly journals Electrical Capacitance Tomography (ECT) Electrode Size Simulation Study for Cultured Cell

2021 ◽  
Vol 2071 (1) ◽  
pp. 012052
Author(s):  
N A Zulkiflli ◽  
M D Shahrulnizahani ◽  
X F Hor ◽  
F A Phang ◽  
M F Rahmat ◽  
...  
Keyword(s):  
Finite Element ◽  
Cultured Cells ◽  
Electrical Capacitance Tomography ◽  
Finite Element Models ◽  
Capacitive Sensing ◽  
Electrical Capacitance ◽  
Cross Sectional ◽  
Electrode Size ◽  
Cell Monitoring ◽  
Capacitance Tomography

Abstract Cell sensing and monitoring using capacitive sensors are widely used in cell monitoring because of the flexible and uncomplicated design and fabrication. Previous work from many different fields of applications has integrated capacitive sensing technique with tomography to produce cross-sectional images of the internal dielectric distribution. This paper carried an investigation on the capabilities of four 16-channel sensor electrodes with different electrode sizes to detect the change in the dielectric distribution of the cultured cells. All three 16-channel sensor electrodes are designed and simulate on COMSOL 6.3a Multiphysics. The pre-processing results obtained from three finite element models (FEM) of ECT sensor configurations in detecting the cell phantom shows that bigger electrodes size are more sensitive to permittivity distribution.

scholarly journals Modeling and Calibration of Electrical Capacitance Tomography Sensor for Medical Imaging

2018 ◽  
Vol 11 (3) ◽  
pp. 1471-1477 ◽  
Author(s):  
M. Ambika ◽  
S. Selva Kumar
Keyword(s):  
Imaging Techniques ◽  
Low Cost ◽  
Dielectric Medium ◽  
Capacitance Measurement ◽  
Electrical Capacitance Tomography ◽  
Electrical Capacitance ◽  
Cross Sectional ◽  
Capacitance Measurements ◽  
Electrode Capacitance ◽  
Capacitance Tomography

Electrical Capacitance Tomography (ECT) is an imaging technique which generates a cross-sectional image representing the internal permittivity distribution based on external capacitance measurements. It possesses the advantages of being non-radioactive, non-intrusive, non-invasive, high imaging speed and low cost over the conventional imaging techniques. Inter-electrode capacitance measurements are done by exciting electrodes placed around the non-conductive dielectric medium cylinder inside which, the material to be imaged is placed. This paper emphasizes on modelling and calibrating an electrical capacitance tomography sensor using ANSYS APDL with medium as air, water and extending the procedure for normal bone and cracked bone. ECT sensor is modelled by mounting 12 electrodes symmetrically outside the cylinder. The cylinder is made up of Polyvinyl Chloride (PVC) which is non-conductive dielectric medium while the electrodes are made up of Copper (Cu) which is conductive. The electrodes are excited in pairs and the potential distribution which is based on permittivity of the medium is analysed using ANSYS and the capacitance between the electrodes were calculated. The entire electrode modelling, calibration and capacitance measurement for the simulated bone model with and without crack is presented in this paper.

scholarly journals Investigating the Characteristics of Two-Phase Flow Using Electrical Capacitance Tomography (ECT) for Three Pipe Orientations

Processes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 51 ◽  
Author(s):  
Zeyad Almutairi ◽  
Fayez M. Al-Alweet ◽  
Yusif A. Alghamdi ◽  
Omar A. Almisned ◽  
Othman Y. Alothman
Keyword(s):  
High Speed ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Electrical Capacitance Tomography ◽  
Experimental Measurements ◽  
Phase Flow ◽  
Electrical Capacitance ◽  
Liquid Holdup ◽  
Two Phase ◽  
Capacitance Tomography

Experiments of gas–liquid flow in a circular pipe for horizontal and inclined positions (upward/downward) are reported. The characteristics of two-phase flow in terms of liquid holdup (ε(L)) and induced flow patterns are studied using three experimental techniques; time-averaged ε(L) from permittivity profiles using electrical capacitance tomography (ECT), instantaneous ε(L) using two fast-closing valves (TFCV), and high-speed camera images (HSCI) to capture/identify the formed flow patterns. Thus, this experimental setup enables the development of more well-defined flow patterns in gas–liquid two-phase flow and allows for multi-technique verification of the results. Taken from experimental measurements, a model is proposed to predict ε(L) for high and low situations. The correlations are a function of the hydrodynamic dimensionless quantities which provide hydrodynamic similarity. Regarding different pipe orientations, ε(L) predictions are comparable to ε(L) from experimental measurements with accepted accuracy: 88% of the predictions are within ±5–15% and 98% are below ±20%. The correlations also were validated by reported results and against correlations available in the literature and show higher prediction accuracy. It is confirmed that the kinematic similarity which is achieved by the gas–liquid velocity ratios and the inertial forces influence the flow pattern and the liquid holdup.

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