A company owns a refrigeration system whose
refrigeration capacity is 200 tons (1 ton of refrigeration = 211
kJ/min), and you are to design a forced-air cooling system for
fruits whose diameters do not exceed 7 cm under the following conditions: The fruits are to be cooled from 28°C to an
average temperature of 8°C. The air temperature is to remain
above -2°C and below 10°C at all times, and the velocity of
air approaching the fruits must remain under 2 m/s. The cooling section can be as wide as 3.5 m and as high as 2 m.
Assuming reasonable values for the average fruit density,
specific heat, and porosity (the fraction of air volume in a box),
recommend reasonable values for (a) the air velocity approaching the cooling section, (b) the product-cooling capacity of the
system, in kg·fruit/h, and (c) the volume flow rate of air.