Abstrakt

Determination of void fraction in horizontal air-water two-phase flow using gamma ray attenuation technique

S.Y.Adzaklo, E.H.K.Akaho, K.A.Danso, A.Coleman, P.S.Adu, C.P.K.Dagadu,H.A.Affum1, I.I.Mumuni1, Godfred K.Appiah1, I.Lawson1

Gamma ray attenuation method is widely used non-intrusively for measuring void fraction in gas–liquid two-phase flow systems. In this study, singleenergy gamma rays of activity 30mCi fromcaesium-137 were used to measure void fraction in a horizontal air-water two-phase flow system at ambient temperature. The study was done on a test rig made of PVC pipe of diameter 2.54cm. The gamma ray counts for the static calibrations and airwater two-phase flow mixture at various water flow rates were measured using thallium-activated NaI scintillation detector and the void fraction calculated. The trends of the plots of the results obtained compared well with existing trends. When the water flow rate was varied from 6L/min to 16L/min, at a constant air flow rate, the void fraction varied from 0.141 to 0.102 respectively. The experimental results were compared with those obtained fromthe use of the model of Chisholmto obtain the mean deviations. The error marginswere in the range of 0.3%- 4.2%.