Countercurrent flooding in vertical-to-inclined pipes

Journal Article · Mon Dec 31 23:00:00 EST 1990 · Experimental Heat Transfer; (United States)

DOI:https://doi.org/10.1080/08916159108946408· OSTI ID:5116550

Kawaji, M; Thomson, L A ^[1]; Krishnan, V S ^[2]

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1. Dept. of Chemical Engineering and Applied Chemistry, Univ. of Toronto, Toronto, Ontario M5S 1A4 (CA)
2. Thermalhydraulics Branch, Whiteshell Nuclear Research Establishment, Atomic Energy of Canada Ltd., Pinawa, Manitoba R0E 1L0 (CA)

This paper reports on countercurrent flooding data obtained using air and water for vertical-to- downwardly inclined pipes containing elbows of varying angles. Experiments were performed with six different test sections, all having an inner diameter of 51 mm and a 1-m- long vertical tube connected to an inclined or horizontal tube. The flooding data for 112.5{degrees} and 135{degrees} elbow angles were almost identical and showed that these geometries required the largest gas flow rates for flooding among all the geometries tested. The flooding gas velocities for the 157.5{degrees} elbow were slightly less than those of the 112.5{degrees} and 135{degrees} elbows but greater than those of the vertical pipe without any elbow and vertical-to- horizontal pipes at low to moderate liquid flow rates. In all vertical-to-inclined pipes, flooding was initiated in the inclined section at about 15 to 50 cm downstream of the elbow. Due to the countercurrent flow of gas, the liquid stream just downstream of the elbow became highly agitated and a frothy mixture was carried upstream by gas at flooding. At moderate to high liquid flow rates, the liquid was deflected off at the elbow to form a turbulent, jetlike stream that partially broke up into droplets. These droplets were, at the onset of flooding, entrained and carried over by the gas stream.

• OSTI ID: 5116550
• Journal Information: Experimental Heat Transfer; (United States), Journal Name: Experimental Heat Transfer; (United States) Vol. 4:2; ISSN 0891-6152; ISSN EXHTE
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
AIR FLOW
COUNTER CURRENT
FLUID FLOW
GAS FLOW
INCIDENCE ANGLE
LIQUID FLOW
PIPES
TWO-PHASE FLOW