The invention relates generally to thermosyphon coolers, and more particularly, to thermosyphon coolers for use in cooling systems that employ cooling towers. 
Cooling towers are often used to remove heat from heating, ventilating, and air conditioning (HVAC) systems, power plants, and industrial processes.  In general, cooling towers may include nozzles that direct water down through the tower, while a fan, or free circulation, directs air up through the tower.  The interaction between the air and water may promote evaporation of a portion of the water, thereby cooling the remaining water.  In open loop cooling towers, the cooling tower water may be circulated directly through the cooling system, while in closed loop cooling towers, the cooling tower water may be directed over a heat exchanger coil that cools a separate flow of cooling fluid that in turn circulates through the cooling system. 
During evaporation, water may be lost from the cooling tower and impurities, such as salts or other dissolved solids, may be concentrated within the cooling tower.  A portion of the cooling tower water containing concentrated impurities may be removed as blowdown.  To account for water losses due to evaporation and blowdown, makeup water may be added to the cooling towers.  Accordingly, cooling towers may consume very substantial quantities of water, in some cases millions of gallons of water each year, and may be one of the largest consumers of water within a process.