6.2-8. Evaporation Losses of Water in Irrigation Ditch. Water at 25°C is flowing in a covered irrigation ditch below ground. Every 100 ft there is a vent line 1.0 in. inside diameter and 1.0 ft long to the outside atmosphere at 25°C. There are 10 vents in the 1000-ft ditch. The outside air can be assumed to be dry. Calculate the total evaporation loss of water in lbm/d. Assume that the partial pressure of water vapor at the surface of the water is the vapor pressure, 23.76 mm Hg at 25°C. Use the diffusivity from Table 6.2-1.
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Calculate the surface area of the water in the ditch: The surface area of the water in the ditch can be calculated as the product of the width and depth of the ditch. Let's assume the width of the ditch is 5 ft and the depth is 2 ft. Therefore, the surface area of Show more…
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