EMERGENCY!!!!
Heat sterilization of lumber, timbers, and pallets is used to kill insects to prevent their transfer between countries in international trade. This is analogous to food sterilization by heat. A typical requirement here is that the slowest heating point of any wood configuration be held at 56 °C for 30 minutes. Consider hot air heating of
wooden boards that maintains their surface temperature at 70 °C. The boards are stacked outside and in the winter time they can be considered to be at 0 °C when they are brought in for heating. The thermal diffusivity of the wood is 9*10-8 m2/s.
Calculate the time from the start of heating for a 2.5 cm thick board to reach a sterilization temperature of 56 °C at its slowest heating point.
Calculate the heating time when four such boards are stacked together.
Calculate the ratio of the two heating times (for a single board versus when
they are stacked), and explain the ratio.
Note: You’re free to make assumptions regarding any value you think you need in order to solve the problem. Just explain your reasoning behind your assumption in a logical manner.Don’t use Heissler charts to answer this question.
ANSWER: 1) 23 min 2) 363 min 3) 16 explain the solution step by step
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