Air and oxygen sparging is a commonly used strategy to maintain desirable dissolved oxygen (DO) and carbon dioxide (dCO2) levels in mammalian cell culture bioreactors. However, sparging can result in cell damage through high gas entrance velocity and bubble rupture as well as foam accumulation. As a result, sparger design and aeration strategies can be of critical importance for bioreactor operation since they directly affect bubble formation and bubble size distribution. In this study, a 2D bubble-liquid cold flow reactor with a high speed camera is used to capture the bubble formation patterns and dynamic behaviors (such as coalescence and breakup) using various drill-hole sparger designs under varying gas entrance velocities. Bubble size distribution and mass transfer capability are compared. The effect of sparger design and aeration scheme on gas entrance velocity distribution across axial positions of the sparger is also determined. The abovementioned information is then used in a second order moment (SOM) bubble-liquid two-phase turbulent model to determine the effect of sparger design on key hydrodynamic parameters of interest including stress, energy dissipation rate (EDR), and stress-induced-turbulent -energy-production (STEP) within a pilot scale sparged bioreactor. The experimental and simulation studies indicate that relatively uniform bubble size and gas entrance velocity can be obtained through carefully designed drill-hole spargers and aeration schemes. Pilot scale cell culture performance using new spargers will be presented.

Sparger design for improved bubble-liquid hydrodynamics in bioreactors

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.