Discussion
Home ‣ Biochemical Engineering ‣ Agitation and Aeration Comments
- Question
Turbine impeller consists of flat impeller blades with
Options- A. a vertical pitch welded directly to the shaft
- B. a angled pitch welded directly to the shaft
- C. a vertical pitch welded to a horizontal disk
- D. a angled pitch welded to a horizontal disk
- Correct Answer
- a vertical pitch welded to a horizontal disk
- 1. A flooded impeller will lead to poor oxygen transfer rates because
Options- A. bubbles tend to coalesce under the impeller
- B. bubbles tend to break down too rapidly under high shear conditions
- C. bubbles tend to move too quickly through the bulk liquid
- D. the cells clog up the surface of the bubble Discuss
- 2. Transient flow range of mixing speed is obtained for
Options- A. Rei<10
- B. 10<Rei<104
- C. Rei>104
- D. None of these Discuss
- 3. Henry's law relates
Options- A. the partial pressure of oxygen and the saturation concentration of oxygen in the liquid
- B. the oxygen transfer rate and the bubble size
- C. the oxygen transfer rate and the temperature
- D. the oxygen transfer rate to the partial pressure of oxygen in the liquid Discuss
- 4. Which of the following is not considered among the three best-known theories of interphase mass transfer?
Options- A. two-film theory
- B. penetration theory
- C. surface renewal theory
- D. Calderbank and Moo-Young theory Discuss
- 5. A typical ceiling fan would be best described as a(n)
Options- A. radial flow impeller
- B. axial flow impeller
- C. intermig impeller
- D. Rushton turbine Discuss
- 6. The power consumption in a stirring vessel can be assessed by using a
Options- A. dynamometer
- B. strain gauge attached to agitator shaft
- C. watt meter attached to agitator motor
- D. all of these Discuss
- 7. The rate limiting step in the movement of oxygen from the gas phase in a bubble to the cell is the movement of oxygen molecules through
Options- A. gas-liquid interface
- B. bubble boundary layer
- C. bulk liquid
- D. gas phase Discuss
- 8. Swirling and vortex formation can be prevented by
Options- A. using baffles
- B. using diffusion ring with turbines
- C. both (a) and (b)
- D. none of these Discuss
- 9. Gas hold up, characterizing the hydrodynamics in a fermenter, mainly depends on the
Options- A. superficial gas velocity
- B. power consumption
- C. Both (a) and (b)
- D. gas concentration Discuss
- 10. When liquid is pumped through cooling coil in a stirred tank reactor to cool. Which of the following is not correct?
Options- A. If the stirrer speed is increased, the rate will be faster
- B. Baffles in the tank will increase the rate of cooling
- C. Faster cooling rates at a slower rate of pumping
- D. Faster cooling rates at a faster rate of pumping Discuss
Agitation and Aeration problems
Search Results
Correct Answer: bubbles tend to coalesce under the impeller
Correct Answer: 10<Rei<104
Correct Answer: the partial pressure of oxygen and the saturation concentration of oxygen in the liquid
Correct Answer: Calderbank and Moo-Young theory
Correct Answer: axial flow impeller
Correct Answer: all of these
Correct Answer: bubble boundary layer
Correct Answer: both (a) and (b)
Correct Answer: Both (a) and (b)
Correct Answer: Faster cooling rates at a slower rate of pumping
Comments
There are no comments.Programming
Copyright ©CuriousTab. All rights reserved.