MASS TRANSFER STUDIES IN AN AGITATED VESSEL WITH RADIAL-AXIAL IMPELLER COMBINATION

Shwetha Karanth, B.S.Thirumalesh

Abstract: The effect of radial-axial impeller combination in dual configuration was tested for gas liquid mass transfer coefficient (KLa) and compared with that of dual axial impeller (30º Pitched blade) combination. The trials were conducted at gas rates of 2litre/min to 10litre/min and agitation rates of 180rpm to 360rpm.Good mass transfer coefficient was obtained by replacing the lower axial impeller with a radial impeller. Rushton Turbine and Curved blade (half pipe) impeller were used in replacing the lower axial impeller. Amongst the two radial impellers, curved blade resulted in higher KLa than Rushton Turbine at highest gassing rate tested. About 15-35% and 20-48% increase in KLa was observed by replacing lower pitched blade impeller with Rushton and Curved blade impeller each. The results from the present study shows the capability of replacing lower axial impeller with Radial impeller and retrofitting existing lower Rushton Turbine with Curved blade impeller.

Keywords: Mass transfer coefficient, Rushton, Axial, agitated vessel.

DOI: https://doi.org/10.15623/ijret.2015.0407003