| Popis: |
In this study, the dynamics of nitrogen bubbles were characterized in shallow pools of semi-processed sunflower oil at atmospheric pressure and temperatures in the range of 18 to 70°C, using sintered disc spargers with porosities of 5−15 and 20−30 μm. Nitrogen bubbles were mainly ellipsoidal in shape and did not coalesce in the oil. The Sauter mean diameters (SMD) of the nitrogen bubbles ranged from 0.90±0.08 mm to 2.30±0.45 mm; larger bubbles were observed mainly in the rise regions of the shallow oil pools. The SMD of nitrogen bubbles were shown to be highly dependent on the operating temperatures and it was shown that bubble sizes decreased significantly with increasing temperatures. The larger porosity sparger was found to give smaller bubbles in the size range of 0.90±0.08 mm to 1.90±0.42 mm. The time of sparging, over a period of 60 minutes, did not significantly affect the SMD values or the shapes of nitrogen bubbles. |
Full Text from ScienceDirect