Abstract: An improved capillary pumped loop evaporator includes circumferential grooves formed in the outer heat exchanger portion of the evaporator. The grooves open to the interface existing between the heat exchanger and a centrally positioned tubular wick. Axially extending vapor channels are formed in the wick and also open onto the interface. The circumferential grooves continuously communicate with the interface and provide a vapor escape to the vapor channels which direct vapor passage from the evaporator. By shortening the vapor path from the interface, a thinner vapor barrier is possible at the interface which results in more efficient heat transfer.

Abstract: A monogroove high capacity heat pipe has compact evaporator section 30 formed of a plurality of parallel legs 32 which are in fluid communication with a manifold 36 which is in fluid communication with the condensor section 40 encased in a heat radiating fin 42.

Abstract: A sealed heat pipe of uniform cross sectional profile from evaporator to condenser which includes a plurality of capillary channels communicating with a central channel by means of narrow re-entrant groove openings having convergent entrances. A two step method of fabrication includes extruding the re-entrant grooves, then drawing a mandrel through the virgin extrusion.

Abstract: A screen mesh artery (50) supported concentrically within the evaporator section (20) of a heat pipe liquid channel (27) retains liquid (41) in the channel (27) and thereby assures continued and uniform liquid feed to the heat pipe evaporation section (20) during periods of excessive heat transfer.

Abstract: A heat pipe comprising an elongated sealed metallic envelope having at least a pair of longitudinal channels extending along the length thereof. One of the channels is for the circulation of the vapor phase of the working medium in operation and the other for the liquid phase and capillary means are provided to furnish fluid communication therebetween. Dedicated vapor and liquid channels result in low viscous pressure drops, the capillary communication means and circumferential grooving in the vapor channel provide high capillary pressure differences, and circumferential grooving is provided to furnish the high evaporation and condensation film coefficients required. To support higher heat fluxes, wicking can be used to augment the capillary flow from the liquid channel. To support higher evaporator heat flux without the need for wicking means, the heat pipe can be provided with more than one liquid channel, each communicating with the vapor channel by capillary means.

Abstract: A sealed heat pipe of uniform cross sectional profile from evaporator to condenser which includes a plurality of capillary channels communicating with a central channel by means of narrow re-entrant groove openings having convergent entrances. A two step method of fabrication includes extruding the re-entrant grooves, then drawing a mandrel through the virgin extrusion.