Experimental Study On The Mechanism Of The Flooding In Narrow Rectangular Channels

In this paper, the author describes an experimental study on the flooding which produced by gas-liquid countercurrent flow in vertical narrow rectangular channels in the circulating loop, under the condition of ordinary temperature and pressure. Two-phase flow is developed in a 500mm high and 50mm wide rectangular channel with the space of 5mm between the two parallel plates. Three different entrances, namely bell-mouthed entrance, plane entrance and inclined entrance are used in order to determine the influence of entrance shapes upon the flooding phenomenon. On the basis of the recording of flooding phenomenon, the pressure of the test section, the onsets of the flooding, the completely carryout of the water, the reversal of the flow direction and the disappearance of the flooding, the onsets of flooding with different entrances and the characteristics of range of pressure change in the experimental passage under the circumstances of big flow and minor flow have been analyzed, compared with the characteristics in the flooding process of big passageway in round pipes. The down flow rate with the gas velocity has been plotted. The discussion of factors contributing to the completely carryout of the water and the reversal of the flow direction, leads to the different Wallis-type correlations to describe the onsets of flooding with different entrances, the effects of which on flooding phenomenon has been analyzed.