Abstract: The present invention relates to an improvement in a fixation roll consisting of several heat pipes embedded in the thick wall of the hollow cylindrical core in the axial direction, and features the fact that each of the heat pipes consisting of a copper tube and encapsulated water as the operating fluid is heated to allow the water as the operating fluid to evaporate to generate pressure and cause the heat pipe to expand and tightly fit onto the inner wall surface of the cylindrical bore in the core so as to form an integral and monolithic structure comprising the heat pipe and the core. Since the heat pipe is firmly fitted to the inner wall surface of the cylindrical bore in the core, a high quality fixation roll exhibiting a uniform surface temperature distribution is provided. Since the installation of the heat pipe is effected by means of the tube expansion, no strict dimensional control of the diameters of the bore for inserting the heat pipe as well as the heat pipe is required.

Abstract: In a boiler or an industrial furnace, a temperature detecting sensor is mounted at the heat absorbing side of a heat pipe of a waste heat recovery device which is disposed in part of the path of exhaust gas. With an output signal of the temperature detecting sensor, a flow rate control valve is controlled, and a liquid discharging shield is utilized to maintain the flow rate of the liquid to be supplied in correspondence with the flow rate of the liquid to be discharged. The effective area of the heat pipes coming in contact with the liquid is varied to maintain the temperature at a heat absorbing side higher than the dew point of sulfur oxide, thus preventing the heat pipes from corrosion, exhaust ducts and so on, and allowing heat absorbing operation to be performed in accordance with the exhaust gas discharge temperature.

Abstract: Heat pipes comprising an outer tubular material closed at both ends, a wick of metal fibers, an inner tubular material covered with the wick and inserted in the outer tubular material and a heat transfer volatile liquid confined in the closed outer tubular material. An evaporation region and a condensing region are respectively constituted in the end portions of the outer tubular material. The liquid in the evaporation region vaporizes when heated and the vapor is passed to the condensing region to condense while giving the heat of the vapor to other materials outside the heat pipe, and the condensed liquid is returned to the evaporation region by the capillary action of said wick, thus repeating a cycle of the evaporation and condensation.

Abstract: Heat pipes comprising an outer tubular material closed at both ends, a wick of metal fibers, an inner tubular material covered with the wick and inserted in the outer tubular material and a heat transfer volatile liquid confined in the closed outer tubular material. An evaporation region and a condensing region are respectively constituted in the end portions of the outer tubular material. The liquid in the evaporation region vaporizes when heated and the vapor is passed to the condensing region to condense while giving the heat of the vapor to other materials outside the heat pipe, and the condensed liquid is returned to the evaporation region by the capillary action of said wick, thus repeating a cycle of the evaporation and condensation.