Agitation and Aeration Questions

• An aerated bioreactor will increase oxygen transfer rates with the addition of detergents because it
• The average fractional gas hold up (H) can be given as (where Zf and Zl are the level of aerated and clear liquid respectively)
• Vortexing in stirred tank reactors can be prevented by
• A typical ceiling fan would be best described as a(n)
• Which of the following is not considered among the three best-known theories of interphase mass transfer?
• Henry's law relates
• Transient flow range of mixing speed is obtained for
• A flooded impeller will lead to poor oxygen transfer rates because
• Turbine impeller consists of flat impeller blades with
• The power consumption in a stirring vessel can be assessed by using a
• 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
• Swirling and vortex formation can be prevented by
• Gas hold up, characterizing the hydrodynamics in a fermenter, mainly depends on the
• When liquid is pumped through cooling coil in a stirred tank reactor to cool. Which of the following is not correct?
• If liquid density and viscosity remains constant, then the Reynolds number in a stirred tank reactor will vary with the
• The oxygen uptake requirements of a microbial population is characterized by the following parameters: μm = 0.2 h-1, K0 = 0.2 mg O2.l-1, Y0 = 0.5 mg dry weight/mg O2 and C0,crit=0.8 mg.l-1 The required concentration of cells is 1000 mg.l-1 and the saturation oxygen concentration of the medium is 5.8 mg.l-1. The required KLa must be greater than
• Radial flow impellers
• What is the ratio of diameter of impeller to the diameter of tank (Da:Dt)?
• The volume of liquid (VL) in a cylindrical reactor can be calculated from the liquid height (HL) and tank diameter (Dt) using the following equation
• Which of the following impellers are used for wide range of viscosities?