Investigation of Liquid Dispersion in the Packed-Bed by Electrical Resistance Tomography

Volume 5: Fusion Engineering; Student Paper Competition; Design Basis and Beyond Design Basis Events; Simple and Combined Cycles ◽

10.1115/icone20-power2012-54841 ◽

2012 ◽

Author(s):

Takeshi Eda ◽

Achyut Sapkota ◽

Masahiro Takei

Keyword(s):

Liquid Flow ◽

Electrical Resistance ◽

Packed Bed ◽

Electrical Resistance Tomography ◽

Entire Cross Section ◽

Basic Model ◽

Liquid Dispersion ◽

Flow Phenomena ◽

Radial Dispersion ◽

Gas Liquid Flow

Revealing gas-liquid permeable flow phenomena in the porous media is helpful for the environmental impact assessment of geological disposal of radioactive waste and purification of radioactive contamination water. This paper aims to investigate the liquid phase dispersion inside co-current downward gas-liquid flow in the bed packed with spherical particle as basic model. Water and air are injected from the top center of column, and water is spreading to the entire cross-section flowing down along the column. Radial dispersion of water is captured by electrical resistance tomography on several axial positions. The results indicated that liquid flow rate have impact on radial dispersion of water.

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SIMULATION OF ELECTRODE FOR DUAL-MODALITY ELECTRICAL RESISTANCE TOMOGRAPHY AND ULTRASONIC TRANSMISSION TOMOGRAPHY FOR IMAGING TWO-PHASE LIQUID AND GAS

Jurnal Teknologi ◽

10.11113/jt.v77.6436 ◽

2015 ◽

Vol 77 (17) ◽

Author(s):

Fazlul Rahman Mohd Yunus ◽

Ruzairi Abdul Rahim ◽

Leow Pei Ling ◽

Nor Muzakkir Nor Ayob ◽

Yasmin Abdul Wahab ◽

...

Keyword(s):

Liquid Flow ◽

Electrical Resistance ◽

Region Of Interest ◽

Gas Bubble ◽

3D Numerical Modeling ◽

Electrical Resistance Tomography ◽

Two Phase ◽

Transmission Tomography ◽

Dual Modality ◽

Gas Liquid Flow

Accurate multiphase flow measurement of gas/liquid, liquid/solid and liquid/liquid flow is still challenging for researchers in process tomography. The reconstructed images are poor particularly in the center area because of ill-posed inverse problems and limited of measurements data. Dual-modality tomography has been introduced to overcome the problem by means each modality is sensitive to specific properties of materials to be imaged. This paper proposed combination of ultrasonic transmission tomography (UTT) and electrical resistance tomography (ERT) for imaging two phase gas/liquid. In the proposed combination, detection ability in the medium of interest improved because two different images in the same space can be obtained simultaneously. This paper presents 3D numerical modeling approach using COMSOL software for ERT excitation strategy and electrode pre-designed geometry. Electrical resistance tomography (ERT) can be implemented for gas/liquid flow if the liquid is conductive. The objectives of this work is to analyze the optimum electrode dimension and shape in order to improve the situation of: (1) gas bubble detection located in the centre of the medium, (2) potential distribution and current density in a conductive medium, the developed numerical model simulated the changes in resistivity of the conductive material, with variations of electrode sizes, with opposite current excitation implemented into the region of interest. Simulation results show that the electrode size of 12 mm (w) × 40 mm (h) is suitable, which gives a good detection of center gas bubble with diameter 10mm in 100-mm-diameter acrylic vessel. Finally the findings are verified with Image reconstruction using Linear Back Projection (LBP) which gives good indication of the 10mm gas bubble.

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