#Question id: 14334
#Section 5: Bioprocess Engineering and Process Biotechnology
Laboratory-scale fermenters are usually mixed using small stirrers with electric motors rated between 100 and 500 W. One such motor is used to drive a 7cm turbine impeller in a small reactor containing fluid with the properties of water. The stirrer speed is 900 rpm. Estimate the power requirements for this process.
#Question id: 14335
#Section 5: Bioprocess Engineering and Process Biotechnology
A cylindrical stirred bioreactor of diameter and height 2 m has a Rushton turbine one-third the tank diameter in size. The bioreactor contains Newtonian culture broth with the same density as water and with viscosity 4 cP. If the specific power consumption must not exceed 1.5 kW m-3, determine the maximum allowable stirrer speed. What is the mixing time under these conditions? __________
#Question id: 14336
#Section 5: Bioprocess Engineering and Process Biotechnology
A cylindrical stirred bioreactor of diameter and height 2 m has a Rushton turbine one-third the tank diameter in size. The bioreactor contains Newtonian culture broth with the same density as water and with viscosity 4 cP. The tank is now aerated. In the presence of gas bubbles, the approximate relationship between ungassed power number (NP)0 and gassed power number (NP)g is: (NP)g =0.5 (NP)0. What maximum stirrer speed is now possible in the sparged reactor? Estimate the mixing time.
#Question id: 14337
#Section 5: Bioprocess Engineering and Process Biotechnology
#Question id: 14338
#Section 5: Bioprocess Engineering and Process Biotechnology
Quasi steady state condition is
#Question id: 14339
#Section 5: Bioprocess Engineering and Process Biotechnology
In continuous culture which phase is usually longer?