Blocks of filleted fish, 5 cm thick are to be frozen in a plate freezer (by contact with a cold surface on both sides). The temperature of the plates are -28C, with an average freezing temperature of -5C. The properties of the fish are: density = 1100 kg/m with the moisture content of 70% w/w and the thermal conductivity of frozen fish is 1.7 W/mk. Latent heat of freezing of water is 334 kJ/kg. The sensible heat effects and heat loss will be neglected and assume perfect contact between the fish blocks and the plate surface. Estimate: a. Estimate the time for complete freezing of the blocks (4 marks) b. What will be the freezing time if he blocks are packed in carton boxes? The thickness of the carton is 1.2 mm and its thermal conductivity is 0.08 W/mK. (6 marks)