Study of primary atomisation phenomenon of modified starch solution stream at elevated temperature

The objective of the work was to study the primary atomisation phenomenon of the starch-urea-borate complex solutions at elevated temperature. Firstly, the dynamic viscosity and surface tension of the solutions were studied as a function of temperature and applied shear rate. Secondly, using a high-speed camera (Phantom v91) and phase Doppler anemometry, the jet breakup dynamics, Sauter mean diameter and droplet velocity vectors were studied. A shearthinning behaviour followed by shear thickening was observed for all solution compositions. The surface tension was decreased concomitantly with an increase in solution temperature. However, an increasing trend in a spray cone angle was noticed when solution temperature was elevated up to 80°C. The phase Doppler anemometry studies revealed that at 80°C solution temperature and 15 bar load pressure, the spray droplets start getting uniform sizes and move in random directions at 120 cm downstream of the nozzle exit. © W. S. Maney &Son Ltd 2014.