#Question id: 14229
#Section 5: Bioprocess Engineering and Process Biotechnology
A fermenter is maintained at 35⁰C by water circulating at a rate of 0.5 kg s^-1 in a cooling coil inside the vessel. The inlet and outlet temperatures of the water are 8⁰C and 15⁰C respectively. The length of the cooling coil is increased by 50%. In order to maintain the same fermentation temperature, the rate of heat removal must be kept the same. Determine the new cooling-water flow rate and outlet temperature by carrying out the following calculations. The heat capacity of the cooling water can be taken as 4.18 kJ kg^- 1 o C^- 1. By how much are the cooling-water requirements reduced after the new coil is installed?_____________
#Question id: 14230
#Section 5: Bioprocess Engineering and Process Biotechnology
In current service, 20 kg s^-1 cooling water at 12⁰C must be circulated through a coil inside a fermenter to maintain the temperature at 37⁰C The coil is 150 m long with pipe diameter 12 cm; the exit water temperature is 28⁰C After the inner and outer surfaces of the coil are cleaned it is found that only 13 kg s^-1 cooling water is required to control the fermentation temperature. Calculate the overall heat-transfer coefficient before cleaning. _____________
#Question id: 14231
#Section 5: Bioprocess Engineering and Process Biotechnology
In current service, 20 kg s^-1 cooling water at 12⁰C must be circulated through a coil inside a fermenter to maintain the temperature at 37⁰C The coil is 150 m long with pipe diameter 12 cm; the exit water temperature is 28⁰C After the inner and outer surfaces of the coil are cleaned it is found that only 13 kg s^-1 cooling water is required to control the fermentation temperature. Calculate the overall heat-transfer coefficient before cleaning. What fraction of the total resistance to heat transfer before cleaning was due to fouling deposits?____________
#Question id: 14232
#Section 5: Bioprocess Engineering and Process Biotechnology
#Question id: 14233
#Section 5: Bioprocess Engineering and Process Biotechnology
Nutrient medium is to be heated from 10⁰C to 28⁰C is a single-pass countercurrent shell-and-tube heat exchanger before being pumped into a fed-batch fermenter. Medium passes through the tubes of the exchanger; the shell-side fluid is water which enters with flow rate 3 x 10^4 kg h^- 1 and temperature 60⁰C pre-heated medium is required at a rate of 50 m^3 h^-1. The density, viscosity and heat capacity of the medium are the same as water; the thermal conductivity of the medium is 0.54 Wm^- 1 ⁰C ^- 1. It is proposed to use 30 steel tubes with inner diameter 5 cm; the tubes will be arranged in line. The pipe wall is 5-mm thick; the thermal conductivity of the metal is 50 Wm^- 1 ⁰C ^- 1. The maximum linear shell-side fluid velocity is estimated as 0.15 m s^-1. Calculate the overall heat-transfer coefficient._________
#Question id: 14234
#Section 5: Bioprocess Engineering and Process Biotechnology
Nutrient medium is to be heated from 10⁰C to 28⁰C is a single-pass countercurrent shell-and-tube heat exchanger before being pumped into a fed-batch fermenter. Medium passes through the tubes of the exchanger; the shell-side fluid is water which enters with flow rate 3 x 10^4 kg h^- 1 and temperature 60⁰C pre-heated medium is required at a rate of 50 m^3 h^-1. The density, viscosity and heat capacity of the medium are the same as water; the thermal conductivity of the medium is 0.54 Wm^- 1 ⁰C ^- 1. It is proposed to use 30 steel tubes with inner diameter 5 cm; the tubes will be arranged in line. The pipe wall is 5-mm thick; the thermal conductivity of the metal is 50 Wm^- 1 ⁰C ^- 1. The maximum linear shell-side fluid velocity is estimated as 0.15 m s^-1. Calculate the log-mean temperature difference _________