Patent GB-368776-A (GB)
Abstract: 368,776. Heat -- storing apparatus heating by circulation of fluids. NORTH, N. E., 86, Strand, London. Dec. 4, 1930, No. 36623. [Class 64 (ii).] In a heat storage system, a body of liquid in contact with a heating element and serving as a heat storage medium is brought by relative displacement into heat-exchange relationship with another fluid, e.g. water or steam, when it is desired to transfer heat from the storage medium to said fluid. In one form, Fig. 2, a cylindrical container 1 which is preferably covered with insulating material is partly filled with a heat storage liquid in which is immersed electrical heating elements 5 formed by bare conductors wound on insulators and carried on supports 6. The elements 5 are connected to the electric supply by strips 8a and insulated conductors 8 which are led from the container 1 through insulated bushings 7. The fluid to which heat is to be imparted is passed through a coil 12 in the container, the heat storage liquid being displaced into contact with the coil 12 by a hollow cylinder 16 which has wheels 23 running on guide rails 27. The displacement is effected under control of a thermostat in the fluid circulating tubes which operates the switchgear of'an electric motor 32 rotating through gear 33 a screw 17 engaging a nut 19 attached to cylinder 16. The cylinder 16 may be partly filled with the same heat storage liquid as is in the container 1, and both may contain swarf, metal or other solids of high thermal capacity. The container 1 may be open to the atmosphere, or may be closed and have a low-pressure relief valve which, when glycerine is employed, allows the water vapour to be driven off, excluding air from the container ; the vent pipe from the valve may have a condenser for returning glycerine in the vapours to the container 1. In a modification, Fig. 7, an open bottomed cylinder 40 is provided in the container 1, the liquid in the container being raised into contact with the fluid circulating pipes 12 by displacing liquid from the cylinder 40 by forcing air by a pump 43 from the container into the cylinder. The pump 43 operates continuously, a return pipe 45 provided for the air being closed by a valve 46 operated by a thermostat in the fluid-circulating system when the displacement is required. The electric heating elements 70 are in a vessel 71 which contains liquid which may be of higher electrical resistance at the temperature of working than the liquid in the container. In a further form, Fig. 5 (not shown), the displacement of the heat storage liquid is effected by pumping liquid from a compartment in the container into the tank. Normally a continuous circulation of the liquid between the container and the compartments is provided, the pump operating continuously, a valve in the return pipe being closed by thermostatic control from the fluid-circulating system when displacement is required. Glycerine, ethylene glycol, mannitol, dulcitol, diphenyl, &c. may be used as heat-storage liquids. The Provisional Specification describes a construction in which the pipes of the fluid-circulating system are displaceable relatively to the heat storage liquid.