The insulation ability of an insulator with the presence of moisture would

Related MCQs

• 200 kg of solids (on dry basis) is subjected to a drying process for a period of 5000 seconds. The drying occurs in the constant rate period with the drying rate as, Nc = 0.5 × 10-3 kg/m2 .s. The initial moisture content of the solid is 0.2 kg moisture/kg dry solid. The interfacial area available for drying is 4 m2 /1000 kg of dry solid. The moisture content at the end of the drying period is (in kg moisture/kg dry solid).
• In a laboratory test run, the rate of drying was found to be 0.5 x 10-3 kg/m2 .s, when the moisture content reduced from 0.4 to 0.1 on dry basis. The critical moisture content of the material is 0.08 on a dry basis. A tray dryer is used to dry 100 kg (dry basis) of the same material under identical conditions. The surface area of the material is 0.04 m2 /kg of dry solid. The time required (in seconds) to reduce the moisture content of the solids from 0.3 to 0.2 (dry basis) is
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• A 10 cm dia steam pipe, carrying steam at 180°C, is covered with an insulation (conductivity = 0.6 W/m.°C). It losses heat to the surroundings at 30°C. Assume a heat transfer co-efficient of 0.8 W/m2 .°C for heat transfer from surface to the surroundings. Neglect wall resistance of the pipe and film resistance of steam. If the insulation thickness is 2 cms, the rate of heat loss from this insulated pipe will be
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