Question: A hydrocooling unit can cool fruits and vegetables from 30 to 5 C at a rate of 20,000 kg/h under the following conditions: the channel is 3 m wide by 90 cm high. The water is circulated and cooled by the evaporator section of a refrigeration system. The refrigerant temperature inside the evaporator coils is to be -2 C, and the water temperature is not to drop below 1 C and not to exceed 6 C. Assuming reasonable values for the average product density, specific heats, and space taken up by the fruits, recommend reasonable values for
(a) how long the fruits and vegetables need to remain in the channel,
(b) the length of the channel,
(c) the water velocity through the channel,
(d) the velocity of the conveyor and thus the fruits and vegetable through the channel,
(e) the refrigeration capacity of refrigeration system, and
(f) the type of heat exchanger for the evaporator and the surface area on the water side.