The Bach Impeller Solution
The Bach impeller operates in a fundamentally different manner than an axial flow impeller which is essentially a downward pumping device. Notably, with the Bach impeller the fluid does the mixing, not the impeller.
The Bach impeller draws fluid from the bottom of the vessel up into its conical structure and then expels the fluid to the sides of the structure, setting up a gentle uniform laminar flow of the liquid in the vessel, without damage associated with velocity differentials, hydrodynamic shear forces or differing mixing zones.
Increasing the size of the Bach impellers to accommodate larger bioreactor vessels, has absolutely no adverse effect on the process. Even the speed at which the Bach impeller operates can be increased to deal with larger volumes, without the high shear rates of axial flow impellers. The Bach impeller is fully scalable to large vessels, without the need to develop or adopt process optimization techniques to compensate for the laws of physics that plague conventionally equipped bioreactors.
Even in small bioreactors, the cell propagation efficiency of the Bach impeller is considerably better than in conventionally equipped bioreactors using normal concentrations of micro-carriers and can be increased significantly due to the ability of the Bach impeller to hold higher concentrations of micro-carriers in suspension. This enhanced degree of efficiency per unit volume can be maintained even when scaling to larger vessels.