Baby carrots with an average diameter of 1 cm and an initial temperature of 20^oC are blanched to give a center temperature of 80^oC prior to further canning process. Hot water at a temperature of 98^o C is used for blanching when a rotary blancher is used. Calculate how much of the time the rotary shaft needs to keep the carrots soaked in the hot water bath? Assume the rotary blancher has a surface heat transfer coefficient of 290 Wm^-2K^-1. The baby carrots have a specific heat of 3.5 kJ kg^-1 °C^-1, a thermal conductivity of 0.36 Wm^-1K^-1, and a density of 985 kg m^-3. 

sphere, (b) slab, (c) cylinder
 

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1.0 10.0 0.8 0.6 6.0 0.4 4.0 3.0 エ 2.0 1.5 0.2 kO 0 0.25 0.50 0.75 1.0 hr 0.10 (a) 1.0 4.0 2.0 0.8 0.6 1.0 1.5 '0.75 0.4 0.50 0.2 k 0.10 0.25, 0. hl (b) 1.0 10.0. 0.8 6.0 4.0 0.6 3.07 2.0 0.4 1.5 0.2 0.50 0.75 1.0. hr 0.25 (c) 1.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 k cp 82 to | 30 - He 1.0 10.0 0.8 0.6 6.0 0.4 4.0 3.0 エ 2.0 1.5 0.2 kO 0 0.25 0.50 0.75 1.0 hr 0.10 (a) 1.0 4.0 2.0 0.8 0.6 1.0 1.5 '0.75 0.4 0.50 0.2 k 0.10 0.25, 0. hl (b) 1.0 10.0. 0.8 6.0 4.0 0.6 3.07 2.0 0.4 1.5 0.2 0.50 0.75 1.0. hr 0.25 (c) 1.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 k cp 82 to | 30 - He