IN rnrs note we report an extension of an experimental investigation [l] of the maximum stable drop size in the flow of two immiscible liquids in turbulent pipe flow.
In the original investigation the main variables studied were flow rate, inter-facial tension, and dispersed phase viscosity, although dispersed phase density and continuous phase viscosity were varied slightly. Most runs were made at such low volume fraction of dispersed phase (< 05 per cent) that drop interaction was not a consideration, and this variable remains unexplored. The experiments were performed in a 14 in. dia. pipe. Thus pipe diameter is another variable that was not studied, although it was tentatively suggested on theoretical grounds that influence of pipe diameter at a given average velocity, V, might be very small. The present investigation is an attempt to test this suggestion by performing drop breakup experiments in a 14 in. dia. pipe.
The continuous phase in the experiments was tap water, and the dispersed phases were three organic mixtures prepared from technical and reagent grade chemicals. The mixtures were: (1) carbon tetrachloride-isooctane for high interfacial tension and low viscosity, (2) nitrobenzenebenzene for low interfacial tension and low viscosity, (3) carbon tetrachloride-mineral oil for high interfacial tension and high viscosity. The density of each mixture was adjusted to about I to 2 per cent less than that of the continuous phase. The mixtures were equilibrated with water after which relevant properties were measured to within 0.5 per cent except interfacial tension, which is believed accurate to 5 per cent. The properties are given in Table 1.