Q. To increase the oxygen transfer rate in a shake flask culture system, which of the following (s) is/are followed?

View solution

Q. What is/are the major difference(s) between disc and turbine type stirrer?

View solution

Q. Larger propellers turn at the speed of

View solution

Q. A microbial population in a suspension culture will only be limited by oxygen availability if the dissolved oxygen

View solution

Q. Which of the following model holds correct for the two-film theory? (where KL is the mass transfer coefficient, DAB diffusivity and Zf film thickness)

View solution

Q. Froude number is avoided in calculation of power requirements for low viscosity liquid mixing systems when

View solution

Q. A fermentation system has a KLa of 3 s­¹ and a C0* of 5 ppm of O₂. If the bulk liquid is completely depleted of oxygen, then the oxygen transfer rate will be equal to

View solution

Q. During fermentation, the saturation concentration of oxygen was reduced from 7 ppm. to 1 ppm. Which one of the following conclusions can be drawn?

View solution

Q. If the stirrer speed is too slow, bubbles will accumulate and coalescese under the impeller. This phenomenon is known as a

View solution

Q. The maximum solubility of the alkane in the medium is 5 ppm. If the actual dissolved concentration of the alkane in the medium is 1 ppm. what conclusion may be drawn?

View solution

Q. Reynolds (Rei) number for the impeller is given by (where Di, stirrer diameter; N, stirrer speed, ρ, density of fluid and μ, viscosity of fluid)

View solution

Q. The advantage of axial flow impellers over radial flow impellers is that axial flow impellers

View solution

Q. Pure oxygen, if used instead of air will increase oxygen transfer rates because

View solution

Q. For aerated mixing vessels in an aqueous solution, the mass transfer coefficient (kL) co-relating power consumption (Pm) and fermenter volume (V) can be expressed as

View solution

Q. Higher temperatures affect oxygen transfer rates by

View solution

Q. The Intermig impeller is

View solution

Q. Main reason for using baffles in stirred tank reactors are

View solution

Q. During aeration, a cylindrical reactor had a height of 10 m. Without aeration, the height was 7.5 m. Under these aeration and mixing conditions, the gas hold up in the reactor is

View solution

Q. A fermentation system has a KLa of 3 s­¹ and a C0* of 5 ppm of O₂. If the bulk liquid is saturated with oxygen then the oxygen transfer rate will be equal to

View solution

Q. Which of the following would be best described as a radial flow impeller?

View solution