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COBEM 2017
24th ABCM International Congress of Mechanical Engineering
STUDY OF LOCAL PHASE FRACTION IN STRATIFIED DENSE-GAS-LIQUID PIPE FLOW USING GAMMA-RAY DENSITOMETRY
Submission Author:
Daniel Gregório Chagas , SP
Co-Authors:
Daniel Gregório Chagas, Tiago Bicudo, L. Enrique Ortiz-Vidal, MARLON MAURICIO HERNANDEZ CELY, Oscar Mauricio Hernandez Rodriguez
Presenter: Daniel Gregório Chagas
doi://10.26678/ABCM.COBEM2017.COB17-2569
Abstract
The gamma-ray technique is frequently used in multiphase-flow experiments and also in onshore and offshore pipelines for volumetric-fraction measurements. In this work we propose to study the gamma ray technique in a static situation and then discuss the necessary improvements for more precise application. The experiments were performed in a stainless steel pipe with 108.45 mm i.d., maintained in a horizontal position. The gamma densitometer system is composed by a radioactive isotope source of Cs-137 with intermediate emission energy (661.6 keV) and a scintillation detector of Sodium Iodide (Na). A high precision actuator for positioning was designed to allow accurate movements in the vertical direction. The first data was acquired to a static case using a tube with 50% of water and 50% of air. The results have shown a good agreement with the expected and a great potential for the next experiment s. We also realize that the commercial (standard) collimator has not a good enough resolution. We need a much more narrowed beam to achieve the precision in the results expected for the larger facilities which are going to study dense gas-liquid flow. We intend to use oil and SF6 (sulfur hexafluoride) as working fluids to allow mimicking the pre-salt production condition where a liquid-gas flow with density ratio smaller than 10 between the phases is observed.
Keywords
Gamma-ray densitometry, Two-phase Flow, Gas-Liquid Flow, dense gas, Stratified flow
