Every phase. Every vessel. In real time.
Electrical Capacitance Volume Tomography applied to multiphase flow — gas, liquid, and solid distributions resolved inside operating vessels at four frames per second, without intrusion, radiation, or shutdown.
No conventional sensor resolves what is happening inside a pressurised, opaque, multiphase vessel.
Multiphase flow — gas bubbles rising through slurry in a pressurised vessel, liquid slugs forming in pipelines, solids cycling through a fluidised bed — poses a measurement challenge that no point sensor, optical method, or radiographic technique can answer from the outside. Intrusive probes perturb the flow they are meant to measure. Optical methods fail when the medium is opaque. Radiography cannot acquire volumetric data in real time.
As demonstrated in IEEE Sensors Journal (2007, vol. 7, no. 4, pp. 525–535), measuring capacitance between electrode pairs placed on the exterior of a vessel — with no wall penetration — encodes the full 3D permittivity distribution inside. Gas, liquid, and solid phases each carry distinct dielectric properties; their spatial arrangement emerges directly from the permittivity map.
The reconstruction algorithm — 3D Neural Network Multi-criterion Optimization Image Reconstruction Technique (3D-NN-MOIRT) — extends the earlier NN-MOIRT framework for 2D ECT by introducing a 3D sensitivity matrix and network constraints including a 3-to-2D image matching function. Subsequent research identified that most reconstruction algorithms neglect the non-linear relationship between permittivity distribution and measured capacitance, using a linearised sensitivity approach. His feed-forward neural network directly solves the non-linear forward problem — replacing the sensitivity matrix and substantially improving reconstruction accuracy. Configurable multi-channel arrays (8 to 64 channels, deployment-dependent), FPGA-based quadrature phase detection, CMOS T-configuration switching: 0.21–0.42 fF resolution at four frames per second.
From exterior electrode to volumetric image — in real time.
Phenomena previously invisible to any measurement technique.
Warsito and Fan studied the choking transition in a 0.1 m ID circulating fluidised bed using a three-layer 12-channel cylindrical 3D ECVT sensor — capturing real-time solids holdup during the sudden change from dilute solids flow to slugging flow. It was the first volumetric visualisation of the choking phenomenon. In the same research programme, spiral bubble motion dynamics in a gas-liquid bubble column (air and Norpar 15) were tracked across the full 3D volume — behaviour inaccessible to any 2D imaging method.
Wang, Marashdeh, Fan, and Warsito (Sensors, 2010) documented ECVT application to vessels from 1 to 60 inches with complex geometries, including horizontal gas jet penetration in a 12-inch gas-solid fluidised bed. Baidillah, Mukhlisin, and Taruno (Hydrology and Earth System Sciences, 2012) extended the measurement framework to soil water infiltration — demonstrating that the same sensor architecture resolves permittivity distributions beyond industrial fluid systems.
- Choking transition — first volumetric visualisation in a 0.1 m ID CFB
- Spiral bubble dynamics in gas-liquid columns across full 3D volume
- Simultaneous three-phase holdup without intrusive probes
- 1–60 inch vessels; complex geometries including right-angle bends and T-junctions
- Framework extended to geophysical media (soil water infiltration, 2012)
Proven across the hardest flow scenarios.
Each deployment validated in operating conditions that conventional sensors cannot access.
Circulating Fluidised Beds
Real-time solids holdup and choking transition visualisation. First 3D volumetric measurement of the choking phenomenon — previously unresolvable with 2D ECT or point sensors.
Bubble Columns
3D gas and liquid holdups, bubble plume trajectories, and spiral dynamics across the full column volume. Norpar 15 / air system studied by Warsito and Fan.
Three-Phase Systems
Simultaneous gas, liquid, and solid holdup measurement without any intrusive probe. No wall tapping, no optical window, no process interruption.
Gas-Solid Fluidised Beds
Horizontal gas jet penetration imaging in 12-inch beds. Phase distribution, jet shape development, and bubble dynamics resolved volumetrically.
Pipeline & Complex Geometry
Right-angle bend and T-junction sensor configurations. Slug flow, stratified flow, and slug-to-annular transitions in operating pipelines.
Geophysical & Environmental
ECVT applied to soil water infiltration in vessel experiments (Baidillah, Mukhlisin, Taruno, 2012) — demonstrating the framework's reach beyond industrial fluid systems.
ECVT Industrial
Field-deployable ECVT for continuous process monitoring — from large-diameter production columns to pipeline installations. Configurable multi-channel volumetric imaging core, portable data acquisition, real-time permittivity reconstruction. Built from the same measurement architecture proven in academic and industrial research since 2007 — and the platform that ECVT Welins was later developed from for weld and pipeline inspection.