HYSTERESIS EFFECTS IN COUNTERCURRENT GAS-LIQUID FLOW LIMITATIONS IN AVERTICAL TUBE

New experiments on air-water countercurrent flow limitations in a vert ical pipe are presented. The experiments were carried out to investiga te the effect of test procedure on the occurrence of the two countercu rrent flow limitations; namely the onset of flooding and complete carr y-up limits. The results revealed the existence of significant hystere sis effects at both limits particularly for high liquid feed rate. For low liquid feed rate, hysteresis effects were only observed at the co mplete carry-up limit. Some associated visual observations are reporte d and the results were empirically correlated and compared with recent data obtained by others.