Abstract: Apparatus for heat transfer is disclosed. This apparatus is a closed container which is possessed of an input portion and an output portion for heat energy and is provided on the inside thereof with a wick extending throughout from the input portion to the output portion and disposed so that the resistance offered thereby to the flow of liquid gradually decreases from the input side to the output side. The heat medium which is vaporized on the input side is moved in the direction of the output side by virtue of the difference of pressure created inside the container. The heat medium which is deprived of heat and consequently liquefied on the output side is moved within the wick in the direction of the input side by virtue of capillary action coupled with the suction resulting from the vaporization of the heat medium in the input portion.

Abstract: In the system for accumulation of heat from solar radiant energy wherein the solar radiant energy is absorbed by heat-absorption means and transferred therefrom to a heat-transfer medium thereby to elevate the temperature of said heat-transfer medium an improvement is attained by using a plurality of heat-absorption members and arranging them in a series connection. These heat-absorption members are individually provided with selectively penetrating membranes capable of reflecting electromagnetic wave energies of the specific magnitudes of heat corresponding to the respective degrees of temperature of the heat-transfer medium. Since the heat-transfer medium is thus divided into a few different stages, the system disclosed herein permits highly efficient accumulation of high-temperature heat energies.