scholarly journals Electrical Resistance Tomography for Control Applications: Quantitative Study of the Gas-Liquid Distribution inside A Cyclone

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6069
Author(s):  
Muhammad Awais Sattar ◽  
Matheus Martinez Garcia ◽  
Robert Banasiak ◽  
Luis M. Portela ◽  
Laurent Babout
Keyword(s):  
Electrical Resistance ◽  
High Speed ◽  
Correction Method ◽  
Electrical Resistance Tomography ◽  
Separation Processes ◽  
Liquid Distribution ◽  
Core Diameter ◽  
Ill Posed ◽  
Inlet Conditions ◽  
And Control

Phase separation based centrifugal forces is effective, and thus widely explored by the process industry. In an inline swirl separator, a core of the light phase is formed in the center of the device and captured further downstream. Given the inlet conditions, this gas core created varies in shape and size. To predict the separation behavior and control the process in an optimal way, the gas core diameter should be measured with the minimum possible intrusiveness. Process tomography techniques such as electrical resistance tomography (ERT) allows us to measure the gas core diameter in a fast and non-intrusive way. Due to the soft-field nature and ill-posed problem in solving the inverse problem, especially in the area of low spatial resolution, the reconstructed images often overestimate the diameter of the object under consideration leading to unreliable measurements. To use ERT measurements as an input for the controller, the estimated diameters should be corrected based on secondary measurements, e.g., optical techniques such as high-speed cameras. In this context, image processing and image analysis techniques were adapted to compare the diameter calculated by an ERT system and a fast camera. In this paper, a correction method is introduced to correct the diameter obtained by ERT based on static measurements. The proposed method reduced the ERT error of dynamic measurements of the gas core size from over 300% to below 20%, making it a reliable sensing technique for controlled separation processes.

A NOVEL TWO-STAGE GENETIC ALGORITHM FOR IMAGE RECONSTRUCTION OF ELECTRICAL RESISTANCE TOMOGRAPHY

2010 ◽  
Vol 01 (04) ◽  
pp. 523-542
Author(s):  
SANAZ ASGARIFAR ◽  
JAVAD FROUNCHI ◽  
MOHAMMAD HOSSIEN ZARIFI ◽  
AMIN MAHDIZADEH
Keyword(s):  
Genetic Algorithm ◽  
Image Reconstruction ◽  
Electrical Resistance ◽  
Process Time ◽  
Initial Population ◽  
Two Stage ◽  
Electrical Resistance Tomography ◽  
Random Group ◽  
Ill Posed ◽  
Resistivity Inversion

In this paper, we present a combined GA-ERT method based on two-stage genetic algorithm for image reconstruction in electrical resistance tomography (ERT). Image reconstruction in ERT is an ill-posed inverse problem and we have replaced the reverse solver by a two-stage optimization algorithm. The first stage of GA-ERT is reach to an approximate shape and location of the object. Also in this stage, we proposed a new electrode arrangement for ERT forward solver to reduce the process time of the forward problem. In the second stage, the GA employs result of the first stage as an initial population instead of a random group. Therefore with the local zoom, the GA can be employed to obtain the shape and location of the object more precisely. Experimental results of numerically solved ERT by the GA are also presented and compared to those obtained by other more established inversion methods such as modified Newton–Raphson (mNR) and RES2DINV program which is a standard 2-D resistivity inversion program. Results show that the proposed method can efficiently improve the ill-posed condition of ERT image reconstruction problem and can superiorly enhance the quality of ERT images.

Experimental Investigation of Volume Fraction in an Annulus Using Electrical Resistance Tomography

SPE Journal ◽  
2019 ◽  
Vol 24 (05) ◽  
pp. 1947-1956 ◽  
Author(s):  
Syed Raza Rehman ◽  
Alap Ali Zahid ◽  
Anwarul Hasan ◽  
Ibrahim Hassan ◽  
Mohammad A. Rahman ◽  
...  
Keyword(s):  
Multiphase Flow ◽  
Electrical Resistance ◽  
High Speed ◽  
Volume Fraction ◽  
Flow Behavior ◽  
Complex Flow ◽  
Flow Loop ◽  
Electrical Resistance Tomography ◽  
Horizontal Drilling ◽  
Hole Cleaning

Summary Horizontal drilling technology has shown to improve the production and cost–effectiveness of the well by generating multiple extraction points from a single vertical well. The efficiency of hole cleaning is reduced because of the solid–cuttings accumulation in the annulus in cases of extended–reach drilling. It is difficult to study the complex flow behavior in a drilling annulus using the existing visualization techniques. In this study, experiments were carried out in the multiphase flow–loop system consisting of a simulated drilling annulus using electrical resistance tomography (ERT) and a high–speed camera. Real–time tomographic images (quantitative visualization) of multiphase flow from ERT were compared to the actual photographs of the flow conditions in a drilling annulus. The quantitative analysis demonstrates that ERT has a wide potential application in studying the hole–cleaning issues in the drilling industry.

scholarly journals Visualisation of flow pattern and measurement of liquid distribution in a random packed column using electrical resistance tomography (ERT)

2021 ◽  
Author(s):  
Nazar Aoda
Keyword(s):  
Flow Pattern ◽  
Flow Rate ◽  
Electrical Resistance ◽  
Packed Column ◽  
Operating Conditions ◽  
Flow Mode ◽  
Electrical Resistance Tomography ◽  
Liquid Distribution ◽  
Flow Rates ◽  
Good Agreement

The aim of this research is to use Electrical Resistance Tomography technique (ERT) to measure factors that affect local mass transfer at various axial locations in a random packed column with diameter 0.3m and bed height 150cm filled with 2 cm plastic spheres. These factors are: liquid maldistribution, velocity profiles, and flow pattern. The system was designed to run in a trickling down-flow mode and a full liquid up-flow mode. Experiments were performed at flow rates of 3, 6, and 9 gpm (or 0.27 x 10⁻², 0.54 x 10⁻² and 0.8 x 10⁻² m³/m² s) and under normal operating conditions of 25C° and atmospheric pressure. The liquid maldistribution factors were measured via ERT technique and the conventional liquid collection method. Both measurements were conducted at various fluid flow rates at different bed heights. The results of ERT were in very good agreement with the conventional method. The standard deviation values were 17% and 21% at flow rates 3 and 6 gpm respectively. The numerical values of velocity for full liquid up flow at 3 gpm were 0.83cm/s, 1.2cm/s, 1.2 cm/s and 1.11 cm/s for different heights of 30, 60 and 90 cm respectively and the numerical values of velocity for trickle down flow at 3 gpm were 16.5 cm/s, 22.5 cm/s and 24 cm/ for different heights of 30, 60 and 90 cm respectively. The values of the liquid maldistribution factor for flow rate 3 gpm were 0.43 (30cm), 0.33(60cm) and 0.30 (90cm) and for flow rate 6 gpm were 0.33(30cm), 0.27(60cm) and 0.22 (90cm). By comparison with findings of many studies conducted on liquid distribution in packed bed column, a good agreement was observed on the relation of Mf and flow rates and bed heights.

Investigation of Transition Boundary and Nature of Pulsating Flow in the Trickle Bed Reactors by Electrical Resistance Tomography

2013 ◽  
Author(s):  
Takeshi Eda ◽  
Achyut Sapkota ◽  
Jun Haruta ◽  
Masayuki Nishio ◽  
Masahiro Takei
Keyword(s):  
Liquid Flow ◽  
Electrical Resistance ◽  
Flow Condition ◽  
Pulsating Flow ◽  
Fixed Bed Reactor ◽  
Electrical Resistance Tomography ◽  
Liquid Distribution ◽  
Cross Sectional ◽  
Transition Boundary ◽  
Trickle Bed

A fixed bed reactor that operates in gas-liquid co-current down flow is called Trickle Bed Reactor (TBR). It is widely used in chemical engineering. And, recently used in purification of radioactive contamination from contaminated water generated in the Fukushima Daiichi nuclear power plant. There are several flow conditions that occur in the TBR due to gas and liquid flow rate. Since mass and heat transfer rate and particles wetting depend on flow condition, it is necessary to establish the visualization techniques to understand flow condition, transition boundary and properties of gas liquid flow in TBR. In this study, authors employed the lab-scale TBR, made of 100mm inner diameter acrylic column, packed with particles of two sizes (3, 5 mm) that are used in the actual reactor. Water and air were injected from the top of the column and cross-sectional liquid distribution was captured at the bottom of the column by electrical resistance tomography (ERT). ERT is a tomographic technique that provides the cross-sectional conductivity distribution at the rate of about 50 frames per second by injecting current and measuring voltages between the 16 electrodes that are attached around the column. By analyzing the spatial and temporal characteristics of the liquid distribution obtained by ERT, it was found that particle size has only little impact on induction of pulsating flow and larger particle causes distinct pulses. Smaller particle causes blurred tiny pulses due to higher flow resistance. Larger particle (5 mm) is advantageous for pulsating flow.

A High Speed Current Pulse Electrical Resistance Tomography System for Dynamic Process Monitoring

Volume 1 ◽  
2004 ◽  
Author(s):  
E. W. Randall ◽  
A. J. Wilkinson ◽  
T. M. Long ◽  
A. Sutherland
Keyword(s):  
Current Pulse ◽  
Electrical Resistance ◽  
High Speed ◽  
Industrial Applications ◽  
Electrode System ◽  
Frame Rate ◽  
Manufacturing Cost ◽  
Electrical Resistance Tomography ◽  
Single Plane ◽  
Pulse Technique

This paper describes an instrument for Electrical Resistance Tomography (ERT) measurements based on a current pulse technique which has been shown by the authors to be a viable and easily implemented alternative to conventional AC excited systems. This system enables data to be acquired and recorded at 1000 frames/second on a single plane 16 electrode system and every 50th frame to be reconstructed and displayed to provide a real time display. The high frame rate enables transient phenomena to be investigated. The design incorporates a multiplexor allowing 8 rings of 16 electrodes to be sampled sequentially and thus provide data sets from all planes at 125 frames/second. This data can be processed to provide 3-D reconstructions and for velocity measurements using cross-correlation techniques. The system is primarily intended for use in minerals processing applications and data is presented from electrode systems used in slurry pipeline monitoring. It is suggested that simplified design and low manufacturing cost of the current pulse ERT systems will open the way for wide scale industrial applications.

scholarly journals Visualisation of flow pattern and measurement of liquid distribution in a random packed column using electrical resistance tomography (ERT)

2021 ◽  
Author(s):  
Nazar Aoda
Keyword(s):  
Flow Pattern ◽  
Flow Rate ◽  
Electrical Resistance ◽  
Packed Column ◽  
Operating Conditions ◽  
Flow Mode ◽  
Electrical Resistance Tomography ◽  
Liquid Distribution ◽  
Flow Rates ◽  
Good Agreement

The aim of this research is to use Electrical Resistance Tomography technique (ERT) to measure factors that affect local mass transfer at various axial locations in a random packed column with diameter 0.3m and bed height 150cm filled with 2 cm plastic spheres. These factors are: liquid maldistribution, velocity profiles, and flow pattern. The system was designed to run in a trickling down-flow mode and a full liquid up-flow mode. Experiments were performed at flow rates of 3, 6, and 9 gpm (or 0.27 x 10⁻², 0.54 x 10⁻² and 0.8 x 10⁻² m³/m² s) and under normal operating conditions of 25C° and atmospheric pressure. The liquid maldistribution factors were measured via ERT technique and the conventional liquid collection method. Both measurements were conducted at various fluid flow rates at different bed heights. The results of ERT were in very good agreement with the conventional method. The standard deviation values were 17% and 21% at flow rates 3 and 6 gpm respectively. The numerical values of velocity for full liquid up flow at 3 gpm were 0.83cm/s, 1.2cm/s, 1.2 cm/s and 1.11 cm/s for different heights of 30, 60 and 90 cm respectively and the numerical values of velocity for trickle down flow at 3 gpm were 16.5 cm/s, 22.5 cm/s and 24 cm/ for different heights of 30, 60 and 90 cm respectively. The values of the liquid maldistribution factor for flow rate 3 gpm were 0.43 (30cm), 0.33(60cm) and 0.30 (90cm) and for flow rate 6 gpm were 0.33(30cm), 0.27(60cm) and 0.22 (90cm). By comparison with findings of many studies conducted on liquid distribution in packed bed column, a good agreement was observed on the relation of Mf and flow rates and bed heights.

scholarly journals Limited Angle Electrical Resistance Tomography in Wastewater Monitoring

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1899 ◽  
Author(s):  
Chenning Wu ◽  
Martin Hutton ◽  
Manuchehr Soleimani
Keyword(s):  
Electrical Resistance ◽  
High Speed ◽  
Low Cost ◽  
Radiation Hazard ◽  
Reconstruction Method ◽  
Limited Data ◽  
Electrical Resistance Tomography ◽  
Limited Region ◽  
Image Reconstruction Method ◽  
High Speed Design

Electrical resistance tomography (ERT) has been investigated in monitoring conductive flows due to its high speed, non-intrusive and no radiation hazard advantages. Recently, we have developed an ERT system for the novel application of smart wastewater metering. The dedicated low cost and high-speed design of the reported ERT device allows for imaging pipes with different flow constituents and monitoring the sewer networks. This work extends the capability of such a system to work with partially filled lateral pipes where the incomplete data issue arises due to the electrodes losing contact with the conductive medium. Although the ERT for such a limited region has been developed for many years, there is no study on imaging content within these limited regions. For wastewater monitoring, this means imaging the wastewater and solid inclusions at the same time. This paper has presented a modified ERT system that has the capacity to image inclusions within the conductive region using limited data. We have adjusted the ERT hardware to register the information of the non-contact electrodes and hence the valid measurements. A limited region image reconstruction method based on Jacobian reformulation is applied to gain robustness when it comes to inclusion recovery in limited data ERT. Both simulation and experimental results have demonstrated an enhanced performance brought by the limited region method in comparison to the global reconstruction.

Front-End Circuit in Electrical Resistance Tomography (ERT) for Two-Phase Liquid and Gas Imaging

2014 ◽  
Vol 70 (3) ◽  
Author(s):  
F. R. Mohd Yunus ◽  
R. Abdul Rahim ◽  
Suzanna Ridzuan Aw ◽  
N. M. Nor Ayob ◽  
M. P. Jayasuman ◽  
...  
Keyword(s):  
Electrical Resistance ◽  
High Speed ◽  
Low Cost ◽  
Bubble Radius ◽  
Current Source ◽  
Electrical Resistance Tomography ◽  
Two Phase ◽  
2D Simulation ◽  
Phase Liquid ◽  
Frequency Changes

A steady and precise Voltage Control Current Source (VCCS ) with broad bandwidth plays a very important role in the quality of final images for the Electrical Resistance Tomography (ERT) system. Therefore, a model of current source is proposed in the paper which implement advanced Howland current pump as VCCS. The model are simulated through a software named multisim, and the simulation results show the proposed high-speed operational amplifier (op-amp) LM7171 is capable to produce constant output current at 10 mA (peak) when the frequency changes between 1 kHz to 500 kHz with load varies from 10 Ω to 1 kΩ. A two-dimensional (2D) simulation was performed using COMSOL and the results showed that the model is capable to detect air bubble (radius=10 mm) in a two-phase liquid and gas. The result presented with opposite excitation method with 150 kHz current at 10 mA. The measurement of boundary potentials are significantly influenced by bubble positions particularly towards the boundary. They are hoped to provide useful approaches for the design of practical and low-cost VCCS in ERT system.

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