Abstract: A compressed air energy storage system including a subterranean cavern, a ground level reservoir, a generally vertical shaft and a tunnel connecting the cavern and the lower end of the shaft is disclosed. Air bubbles which form in and rise through the water in the shaft are concentrated at the center of the shaft to thereby form a substantially air free water column in the shaft to insure a constant hydrostatic head in the cavern. The air bubbles are concentrated by imparting a spiral motion to the air bubble/water mixture, primarily with a number of nozzles which inject water into the shaft. Spiral vanes mounted along the interior surface of the shaft, but leaving the shaft substantially unobstructed, aid in imparting rotary motion to the mixture. The bubbles rise along the axis of the shaft and are discharged into the atmosphere. A number of bypass passages parallel the upper region of the shaft and fluidly connect the reservoir with openings in the shaft located a short distance above the nozzles.

Abstract: A system using a number of flash chambers for converting the heat energy of geothermal brine to useful work. The system uses steam from flashed brine to vaporize a portion of distilled water or distillate in one or more heat exchangers to produce steam to drive a turbine which, in turn, operates a generator or the like to produce useful work. Before the distillate reaches the heat exchanger, it is preheated as it flows through a series of flash chambers in countercurrent relationship to the flow of geothermal brine therethrough. The brine flashes in each flash chamber and the flashed vapor mixes with the distillate flowing through the flash chamber to pre-heat the distillate. The heat energy of the unvaporized part of the distillate in the heat exchanger can form additional steam which is also supplied to the turbine. The heat content of the unflashed part of the distillate can be used in several ways to heat a working fluid in a closed loop containing a second turbine.

Abstract: A method and apparatus is disclosed for freezing and subliming uranium hexafluoride (UF.sub.6) as part of a gaeous diffusion plant from which a quantity of the UF.sub.6 inventory is intermittently withdrawn and frozen to solidify it. A plurality of upright heat pipes holds a coolant and is arranged in a two compartment vessel, the lower compartment is exposed to UF.sub.6, the higher one serves for condensing the evaporated coolant by means of cooling water. In one embodiment, each pipe has a quantity of coolant such as freon, hermetically sealed therein. In the other embodiment, each pipe is sealed only at the lower end while the upper end communicates with a common vapor or cooling chamber which contains a water cooled condenser. The cooling water has a sufficiently low temperature to condense the evaporated coolant. The liquid coolant flows gravitationally downward to the lower end portion of the pipe. UF.sub.6 gas is flowed into the tank where it contacts the finned outside surface of the heat pipes.