Question

A fermenter containing 40 m3 of medium (25°C) is going to be sterilized by
the direct injection of saturated steam. The typical bacterial count of the
medium is about 5×1012 m−3
, which needs to be reduced to such an extent
that the chance for a contaminant surviving the sterilization is 1 in 1,000.
The steam (345 kPa, absolute pressure) will be injected with a flow rate of
5,000 kg/hr, which will be stopped when the medium temperature reaches
122°C. During the holding time, the heat loss through the vessel is assumed
to be negligible. After a proper holding time, the fermenter will be cooled by
passing 100 m3
/hr of 20°C water through the cooling coil in the fermenter
until the medium reaches 30°C. The coil has a heat-transfer area of 40 m2
and for this operation the average overall heat-transfer coefficient (U) for
cooling is 2,500 kJ/hr m2 K. The heat-resistant bacterial spores in the
medium can be characterized by an Arrhenius coefficient kd0 of 5.7×10 39 hr
-1 and an activation energy (Ed
) of 2.834×105 kJ/kmol. The heat capacity and
density of the medium are 4.187 kJ/kg K and 1,000 kg/m3
, respectively.
Estimate the required holding time

Answer 1

Answer:

hii i am boy

zom=3015165034

ps=loveu