Multiphase Flow
Applications:
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Multiphase Flow Measurement
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Two phase/Three phase
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Soild/Liquid/Gas
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Lab/Pilot/Production
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Research/Process Monitoring
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Process Development
Key Benefits include:
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Determine flow conditions
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Monitor phase inversion
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Investigates flow rates of multi-component flow
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Characterise flow regimes
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Accurate measurement of multiphase flow
Introduction
Multiphase flow occurs when two or more phases are flowing along a closed or open pipe. The phases may be gas, liquid or solid and two and three phase flow are common (as well as multiple component flow due to immiscibility in the liquids more that one liquid phase may exist). Hence in the “fluid” flowing down the pipe the phases may be fully mixed, fully separated and anything in between depending on the nature and densities of the phases, the degree of turbulence induced in the mixture and the physical geometry of the pipe. Add to this the boundary layer effect at the pipe walls and it is a very complex measurement challenge.
Knowing process flow conditions can be used to manage downstream processes.
It would be highly beneficial to measure the flow of each phase in the pipe, ideally mass and volume, and the degree of mixing within the pipe. This is not possible from within the pipe as the very act of measurement disturbs the flow; hence it has to be from outside the pipe.
Solution
From the early 1980’s the petrochemical sector has invested in process tomography to provide information on multi-phase flows. As noted above, this is an extremely challenging measurement objective and it is only recently that significant advances in software, sensors and instrumentation technology have led to process benefits.
Multiple modalities (of capacitance and resistance tomography) have been fused to provide information on three phase flow. Resistance tomography provides data on water / oil-gas components and capacitance provides data on water-oil / gas components. By taking data contemporaneously, full three phase flow information can be provided, such as air/oil/water.
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At a simpler level of instrumentation, robust sensors have been deployed in marine applications (in deserts / beaches) to provide information on solids flowing during dredging applications
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In addition, advances in cross-correlation have combined with advances in very high speed data collection to provide the cornerstones for mass flow measurement.
The dual modality m3000 must be used in the study of 3 phase flows.
Right Click to zoom
The video above shows from top-left:
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An online measurement of water and air
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An online measurement of oil and air
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An online fusion of the three-phases
The three phase detection of air / water / oil with ITS m3000 multi-modal system
The above shows:
- ERT data (water at pixel height 1-4 out of 20) = 2cm (2.5cm actual)
- ECT data (oil-water phase at pixel height 1-19 out 32) = 6cm (6.5cm actual)
This provides a capability to investigate multiphase / multi-component flow on air / oil / water and similar systems.
References
Qiu, C, Hoyle, BS and Podd FJW (2007) Engineering and application of a dual-modality process tomography system, Flow Measurement and Instrumentation, Vol. 18, 247-254
Qiu, CH, Bagatin, R, Palmery, S and Bolton GT (2007) On-line visualization of asymmetric multi-phase flow in an industrial flow loop using electrical tomographic techniques, Proceedings of the 5th World Congress onIndustrial Process Tomography, Bergen, Norway, 3-6 September 2007
For more information on these papers, please contact ITS.
