Combatting Frazil Ice in Hydroelectric Stations [includes discussion]

This paper reports on a method of precise water temperature measurements with an electric resistance thermometer and recorder and its application as a frazil ice warning system for hydroelectric stations. The fine needle-like ice that is often distributed throughout a volume of moving water or is formed in water cooled below the normal freezing point (32 degrees Fahrenheit or 0 degree centigrade) is called "frazil ice." It is the cause of considerable trouble in the operation of hydro power stations, water works, and other power stations that depend on an uninterrupted water supply. When reliable warning of the impending ice formation can be obtained, adequate steps may, in some instances, be taken to minimize its effect on station capacity. A graphic record of water temperature has been found a reliable means of predicting the formation.