Effect of baffle dimensions on liquid free surface in an agitated vessel with paddle impeller

The vortex depth in an agitated vessel with paddle impeller is measured und er various impeller dimensions and various baffle conditions. The vortex de pth in a nan-baffled vessel is correlated well by using the Froude number a nd the parameter n(p)(0.7)(b/H) which is defined for the power correlation by Kamei et al. The difference of the vortex depth in a baffled vessel from that in a non-baffled vessel is also correlated by using the baffle condit ion parameter n(b)(0.8)(B-w/D). The radius at the intersection of liquid fr ee surface and static level is only affected by the ratio of the paddle imp eller diameter to the vessel diameter. A new estimation method of the radiu s of cylindrically rotating zone from the vortex depth and the intersection radius was proposed. The radius of cylindrically rotating zone decreases w ith increasing baffle condition parameter (h(B)/H) n(b)(0.8)(B-w/D) and van ishes where the baffled condition parameter is 0.24. This condition is inde pendent of the impeller dimensions, and is weaker than the full baffle cond ition.