The U.S. Bureau of Mines has undertaken a program to evaluate the value of energy recovery from incoming cooling and/or service water into deep mine shafts. Through its contractor, Foster-Miller, Inc., The Bureau is proceeding with the design, installation, and operation of a demonstration energy recovery system to be operated in the Hecla Mining Company's Lucky Friday Mine, Mullan, Idaho. The objectives of the program are to verify the predicted energy savings resulting from the use of a turbine generator system to recover the available potential energy of the incoming water, to demonstrate the viability of the system hardware, and to promote the use of this technology throughout the U.S. mining industry. Various types of energy recovery devices were considered including turbines, reverse running pumps, hydrotransformers, and high-pressure heat exchangers. The demonstration system will consist of an impulse turbine directly coupled to a 300-kw induction generator. The turbine is designed to operate over a range of flow between 16 and 47 l/s at a net head of 850 m. This paper discusses energy recovery principles in generic terms and indicates how they were applied to the Lucky Friday installation.
Paper in Proc. Asme 3D Symp. on Small Hydropow. Mach., New Orleans, Louisiana, Dec. 1984, PP. 165-170