An experimental investigation of the effects of gas solubility on the properties of horizontal slug flow

The present work investigates the effects of gas solubility on the fluid dynamic properties of a horizontal two-phase slug flow. Measurements of the size distributions of the liquid slug and of the long bubbles are provided, as well as local measurements of the liquid velocity in the slug, the velocity in the liquid film, the velocity of propagation of the nose of the long bubbles and the pressure drop. These parameters were obtained through two optical techniques: Shadow Sizer (SS) and Particle Image Velocimetry (PIV). The experiments indicate that the solubility has a substantial influence on the flow properties resulting, in particular, in a significant reduction of the local pressure gradient over a relatively short distance (8 m). The data are compared with modified versions of the mechanistic models of Dukler and Hubbard (Dukler, A.E., Hubbard, M., 1975, A model for gas–liquid slug flow in horizontal and near horizontal tubes, Ind. Eng. Chem. Fund. 14(4), 337–347) and of Orell (Orell, A., 2005, Experimental validation of a simple model for gas–liquid slug flow in horizontal pipes, Chem. Eng. Sci. 60, 1371–1381) so that the solubility effects can be taken into account.

► Gas solubility effects on the properties of a horizontal slug flow are studied.
► Solubility reduces by 10% the local pressure gradient over the 4 m test section.
► Solubility of CO2 results in a volume reduction of 30% of the gas phase.
► A simplified model is proposed to account for the solubility effects.
► Model is based on the unit cell approach.