Heat storage heat exchanger

1,146,424. Heat exchanger tubes; heat storing apparatus. COMSTOCK & WESCOTT Inc. 10 Jan., 1967 [7 Nov., 1966], No. 1358/67. Headings F4S and F4U. A heat exchanger or vaporizer apparatus for extracting heat from a heat storage mass in a container 1 comprises an ascending coiled conduit 10 disposed within the container 1 and having turnings of at least two different diameters, the turnings being interspersed to provide a distribution of larger and smaller diameter coils. In the particular heat storage unit shown, the coil conduit through which a heat exchange fluid, e.g. water, is passed has two different coil diameters formed between an inlet 2 and an outlet 3. Water, on passing through the conduit, extracts heat from the heat storage material (e.g. a molten anhydrous alkali metal hydroxide composition, which surrounds conduit 10 in the cylindrical container), forming superheated steam which can then be passed on into a condenser (not shown) submerged in a body of water in order to heat the water. Alternatively aromatic and aliphatic organic compounds may be used as heat exchange fluids. The shape of the coils of the conduit 10 are preferably made to conform to the shape of the heat storage container which can alternatively be, e.g. rectangular or elliptical.