Abstract
After defining recirculation, the paper shows it is a characteristic of the surroundings of a cooling-tower installation and must be considered by the user in his economic calculations and by the manufacturer for the proper selection of a cooling tower to reach a specified cold-water temperature. A knowledge of recirculation factors of installations can be obtained experimentally only by co-ordinated over-all tests on actual cooling-tower installations. The paper develops the methods and equations required for such tests to find the recirculation factor. It then shows how the cold-water temperature is affected by various degrees of recirculation, and how the size of a cooling tower would have to vary, if the cold-water temperature is fixed. Finally, the variation of cold-water temperatures with varying wet-bulb temperatures is studied for a series of fixed recirculation factors, and it is shown that if the recirculation factor increases with decreasing wet-bulb temperatures, a nearly constant cold-water temperature all year round may result.
