Agitator Design for Gas-Liquid Fermenters and Bioreactors. Gregory T. Benz

Chapters 5 and 17.

Summary of Chapter

      This chapter has presented the basics of power draw, flooding, and mechanical effects exhibited by impellers under gassed conditions. More specific information will be presented in Chapter 5, which is about impellers used in gas dispersion.

      List of Symbols

aInterfacial area/volumeklLiquid film coefficientklaOverall mass transfer coefficient (usually treated as one variable)DImpeller diameterHFractional gas holdupNShaft speedNaAeration NumberNCDShaft speed for complete dispersionNFlShaft speed for flooding emergenceNFrFroude numberNReReynolds numberOUROxygen uptake rate.PPower draw, generalPgGassed power drawPuUngassed power drawTTank diameterUsSuperficial gas velocityVgGas volumeVlLiquid VolumeZLiquid heightρLiquid density

References

      1 1 Private communication.

      2 2 Sensel, M.E., Myers, K.J., and Fasano, J.B. (1992). “Gas dispersion at high aeration rates in low to moderately viscous Newtonian liquids.” Paper 1071, AIChE 1992 Annual Meeting.