A cold room in a meat processing industry has for handling products whose external wall is coated with thermal insulating material. Users have observed that the diffusion of vapor occurs through the wall and that the water vapor that diffuses condenses when it reaches the inner surface of the insulating layer, which can cause its rapid degradation. Under current conditions, the ambient air inside the room is maintained at an average temperature of 5°C with a relative humidity of 60%. The insulated wall is 3 m high and 2 m wide, its thickness is 12 mm. The following information is also known: - the solubility of water vapor in the wall material is equal to approximately 0.007 kmol/m3.bar. - the water vapor diffusion coefficient on the wall is equal to 0.2 x10-9 m2/s; - At the inner wall-insulation interface, the water vapor pressure can be considered negligible, since the moisture rapidly condenses upon reaching its surface. (a) Quantitatively analyze the effect of a reduction in moisture relative air in the diffusion rate. (b) Present possible alternatives if it is necessary to reduce condensation
A cold room in a meat processing industry has for handling products whose external wall is coated with thermal insulating material. Users have observed that the diffusion of vapor occurs through the wall and that the water vapor that diffuses condenses when it reaches the inner surface of the insulating layer, which can cause its rapid degradation.
Under current conditions, the ambient air inside the room is maintained at an average temperature of 5°C with a relative humidity of 60%. The insulated wall is 3 m high and 2 m wide, its thickness is 12 mm.
The following information is also known:
- the solubility of water vapor in the wall material is equal to
approximately 0.007 kmol/m3.bar.
- the water vapor diffusion coefficient on the wall is equal to 0.2 x10-9 m2/s;
- At the inner wall-insulation interface, the water vapor pressure can be considered negligible, since the moisture rapidly condenses upon reaching its surface.
(a) Quantitatively analyze the effect of a reduction in moisture relative air in the diffusion rate.
(b) Present possible alternatives if it is necessary to reduce condensation
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