above the clouds
http://farm3.static.flickr.com/2233/...a455a7_b_d.jpg
flight Vienna->Frankfurt, approaching FRA
It's just steam, folks.
Cooling towers are heat rejection devices used to transfer process waste heat to the atmosphere. Cooling towers may either use the evaporation of water to reject process heat and cool the working fluid to near the wet-bulb air temperature or rely solely on air to cool the working fluid to near the dry-bulb air temperature.
