The specifications of the second-hand fermenter are given in Table Q1.2 (a) Determine the liquid depth in the second-hand vessel and confirm that the vessel can be assumed to be of standard Rushton geometry. [4 Marks] (b) A colleague has determined that the impellor speed for the second-hand fermenter will be 70rpm. Using this information and assuming that the power number (Po=P/N3Di5, where P denotes power (W), the fluid density, N the impellor speed (rev s1 ) and Di the impellor diameter) in the fully turbulent region for the second-hand vessel is 6.2, show that the gassed power input (P) to the second-hand vessel should be 0.63kW. [5 Marks] (c) The oxygen transfer rate for this fermentation can be expressed by the correlation Kv=0.0635(VPg)0.95vs0.67 where Kv is the oxygen transfer rate (kmolO2h1m3atm1),Pg/V is the gassed power per unit volume of liquid (HPm3) and va is the superficial gas velocity (mh1). Assuming that the oxygen transfer correlation applies to both vessels, determine the required air supply rate for the second-hand vessel to achieve identical oxygen transfer characteristics to that in the existing vessel. [12 Marks] (d) Would you recommend purchasing the vessel? Explain your answer. [4 Marks] Table Q1.1 Details of existina fermenter Table Q1.2 Details of second-hand fermenter The specifications of the second-hand fermenter are given in Table Q1.2 (a) Determine the liquid depth in the second-hand vessel and confirm that the vessel can be assumed to be of standard Rushton geometry. [4 Marks] (b) A colleague has determined that the impellor speed for the second-hand fermenter will be 70rpm. Using this information and assuming that the power number (Po=P/N3Di5, where P denotes power (W), the fluid density, N the impellor speed (rev s1 ) and Di the impellor diameter) in the fully turbulent region for the second-hand vessel is 6.2, show that the gassed power input (P) to the second-hand vessel should be 0.63kW. [5 Marks] (c) The oxygen transfer rate for this fermentation can be expressed by the correlation Kv=0.0635(VPg)0.95vs0.67 where Kv is the oxygen transfer rate (kmolO2h1m3atm1),Pg/V is the gassed power per unit volume of liquid (HPm3) and va is the superficial gas velocity (mh1). Assuming that the oxygen transfer correlation applies to both vessels, determine the required air supply rate for the second-hand vessel to achieve identical oxygen transfer characteristics to that in the existing vessel. [12 Marks] (d) Would you recommend purchasing the vessel? Explain your answer. [4 Marks] Table Q1.1 Details of existina fermenter Table Q1.2 Details of second-hand fermenter