A cooling bag is commonly used for storing water in hot, arid outdoor environments. The bag made
Question:
A “cooling bag” is commonly used for storing water in hot, arid outdoor environments. The bag made of a thin porous fabric that allows water vapor, but not liquid water, to pass through it. A small amount of water (species A) diffuses through the fabric and evaporates from the surface of the bag. The rate of evaporation is controlled by convective mass transfer from the outer surface of the fabric to the surrounding dry air. The energy for evaporation is supplied by the hot air surrounding the outer surface of the bag. The evaporation of the water cools the remaining liquid water within the bag and a steady-state temperature driving force is established. If the surface temperature of the bag is 293 K, determine the temperature of the surrounding hot air. It may be assumed that the surrounding arid air contains no moisture. At 293 K, the latent heat of vaporization of water is ΔHv,A = 2.45 kJ/g H2O, and the vapor pressure of water is PA = 2.34 × 103 Pa.
Step by Step Answer:
Fundamentals Of Momentum Heat And Mass Transfer
ISBN: 9781118947463
6th Edition
Authors: James Welty, Gregory L. Rorrer, David G. Foster