GB242690A - An improved means for the transfer of heat - Google Patents

Abstract

242,690. Dobbs, A. C. July 29, 1924. Refrigerating, special processes for.-Relates to means for transierring heat energy from a medium at a low temperature, e.g. sea water or the atmosphere, to a high temperature medium, of the type in which the heat is first absorbed by a process of endothermic solution, e.g. using potassium nitrate and water, and then delivered to the high temperature medium, e.g. the steam evolved by evaporation, by separation of the solute from the solvent. The vapour obtained by evaporation at the surface of the solution, which constitutes a cooling mixture, is drawn through an engine or other apparatus, in which its energy is utilised, and then passed through the cooling mixture itself so that any residual heat of the vapour, including its latent heat, is transferred back to the mixture simultaneously with the reintroduction in the opposite direction, on the counter-current principle, of the solvent into the mixture. In the apparatus shown the potassium nitrate or the like is disposed within an annular receptacle 1, which is immersed in sea-water 2 and to which water is supplied from a tank 5. The receptacle 1 communicates with a boiler 3 having a non-conducting covering 4, the lower part of the boiler also containing crystals of potassium nitrate. Steam-pipes or electric heating elements are arranged in a boiler near the surface of the solution, and the heat absorbed from the sea-water in the process of dissolving the potassium nitrate is recovered when the potassium nitrate is separated again from the water and deposited in the boiler. The steam evolved in the boiler may be employed for driving a turbine 8 and then condensed, preferably in a coil 10 located in the receptacle 1. The condensate may be re-circulated from the tank at a rate regulated through the medium of a valve 12 by the pressure in the boiler, or it may be discharged at a level 11 below the apparatus not less than the height of the water barometer. In warm countries, the absorption of heat resulting from the dissolving of the potassium nitrate or the like may be made effective for cooling purposes. Also, if sea-water is supplied for the tank 5, a separation of the salts contained therein is effected in the boiler 3, and these salts may be removed at intervals.