Atomization of viscous fluids using counterflow nozzle

Abstract

In the present work, we study the enhanced atomization of viscous liquids by using a novel twin-fluid atomizer. A two-phase mixing region is developed within the nozzle using counterflow configuration by supplying air and liquid streams in opposite directions. Detailed qualitative and quantitative measurements for droplet size were conducted using shadowgraph technique. Near-field spray images from the nozzle exit suggest that the spray emerges out as a fine droplets with little scope for further atomization. The performance of this nozzle is compared to that of ‘flow-blurring’ nozzle. Three test liquids (Water, Propylene Glycol & Glycerol 85% soln) are used to vary the liquid viscosity in the range from 1 to 133.5 mPa.s. The counterflow nozzle produces a spray whose characteristics are relatively insensitive to fluid viscosity over the range of gas-liquid mass flow ratios between 0.25 and 1.