ATOMIZATION OF HIGH-VISCOSITY AND NON-NEWTONIAN FLUIDS BY PREMIXING

A novel concept of spray generator is described, which combines aerodynamic and mechanical liquid breakup to achieve liquid atomization. In particular, the concept of an air-blast (effervescent) atomizer is combined with the well-known stretch-and-fold mechanism commonly used in mixing high-viscosity fluids. The proposed technology is suitable to generate sprays of high-viscosity and non-Newtonian fluids, and in general enables liquid atomization at significantly lower pressures than conventional nozzles. A prototype spray generator based on this concept was designed, built, and tested with two fluids: an aqueous glycerol solution and a Carbopol polymer dispersion in water. For each fluid, the spray generator performance was studied changing the mass flow rates of fluid and air, and the rotation speed. Shadowgraph images of the spray were analyzed with a custom Matlab application to determine the cone angle and the drop size distribution.