Experimental apparatus and flow instrumentation for the investigation of a quasi-real slug flows in vertical ducts

•Novel experimental techniques for the study of quase-real slug flows presented.•High inverse viscosity numbers and presence of dispersed bubbles in liquid stream.•Experimental apparatus to study the interactions of Taylor and dispersed bubbles.•Dynamic masking for removing the Taylor bubbles in PIV images.•Also allowing the study of Taylor bubbles interface oscillations.