Abstract: An alkali metal heat engine. A thermoelectric generator which circulates alkali metal through a cationic barrier to produce electricity. The device is capable of operating in a reduced gravity or gravity-free environment and without mechanical pumps because it collects and recirculates the liquid alkali metal with capillary wick structures. One capillary wick moves the alkali metal from the cooler side of the barrier to the hotter side, and another wick is used as a bypass structure to recirculate the undiffused alkali metal back to the heat source.

Abstract: A vapor block resistant liquid artery structure for heat pipes. A solid tube artery with openings is encased in the sintered material of a heat pipe wick. The openings are limited to that side of the artery which is most remote from the heat source. The liquid in the artery can thus exit the artery through the openings and wet the sintered sheath, but vapor generated at the heat source is unlikely to move around the solid wall of the artery and reverse its direction in order to penetrate the artery through the openings. An alternate embodiment uses finer pore size wick material to resist vapor entry.

Abstract: A vapor block resistant liquid artery structure for heat pipes. A solid tube artery with openings is encased in the sintered material of a heat pipe wick. The openings are limited to that side of the artery which is most remote from the heat source. The liquid in the artery can thus exit the artery through the openings and wet the sintered sheath, but vapor generated at the heat source is unlikely to move around the solid wall of the artery and reverse its direction in order to penetrate the artery through the openings. An alternate embodiment uses finer pore size wick material to resist vapor entry.

Abstract: An improved heat pipe with an external artery. The longitudinal slot in the heat pipe wall which interconnects the heat pipe vapor space with the external artery is completely filled with sintered wick material and the wall of the external artery is also covered with sintered wick material. This added wick structure assures that the external artery will continue to feed liquid to the heat pipe evaporator even if a vapor bubble forms within and would otherwise block the liquid transport function of the external artery.

Abstract: A structure for more accurately automatically controlling the heat transfer characteristics of a heat pipe with a non-condensible gas. The gas, intermixed with the heat transfer vapor, is largely contained by an expanding and contracting bladder. This permits the vapor pressure of the heat transfer fluid to control the position of the non-condensible gas to vapor front with less back pressure from the gas which is being compressed. The bladder is contained within a structure which is itself enclosed within the interior of the heat pipe evaporator so that the non-condensible gas is held at a constant temperature.

Abstract: Capillary grooves in a heat pipe which are specifically constructed to suppress boiling. Conventionally shaped grooves are constructed with highly polished surfaces. The high polish discourages vapor bubbles which otherwise interfere with the liqud transport function of the arteries. A method of constructing the highly polished grooves by vapor deposition onto matching mandrels is also disclosed.

Abstract: A semiconductor circuit construction in which the semiconductor junction is constructed as an integral part of a heat pipe to eliminate the casing which interferes with heat flow. The semiconductor chip material directly forms one wall of the casing of a heat pipe which is constructed as a hollow wafer-like configuration. A special material formed from a mixture of glass and the semiconductor material and which is directly adjacent to the backside of the semiconductor chip is used as the heat pipe wick.

Abstract: A support structure for a gas laser cavity in which the longitudinal support members are constructed as identical heat pipes with a common thermal interconnection. With this common thermal system, thermal effects and, therefore, thermal expansions are equalized for all members and the laser cavity maintains alignment despite changes in operating temperatures.

Abstract: A heat pipe with limited heat transfer capabilities in one direction. The heat pipe, which transfers heat in one direction in normal fashion, also transfers heat in the reverse direction, but only up to a prescribed point, beyond which the reverse heat flow cuts off. It operates because of the use of a limited liquid filling and at least one artery which is closed at the normal evaporator end and open ended at the normal condenser end.

Abstract: A heat pipe constructed to be bent to conform to a particular mechanical configuration after is is constructed. The wick in the evaporator region is constructed from sintered metal powder; while the wick in another region of the heat pipe is constructed with a screen wick to permit bending the pipe without destruction of the wick. Arteries wound from flexible screen material are continuous through both the sintered wick, into which they are inserted, and the screen wick, to which they are also attached.

Abstract: A condensation collector for accumulating liquid for input to a pump. The collector is a device which is independent of gravity for feeding a pump collecting condensate from a vapor system. A decreasing cross section condenser is cooled to the dew point of the vapor with which it is in contact, and the interior of the collector can be a highly wettable surface or be lined with a capillary material. The collector itself has a narrow region so that as it approaches the pump input it also acts as a capillary pump. Condensed liquid is therefore fed into the pump by the collector regardless of the absence of gravity.

Abstract: A specially constructed heat pipe for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

Abstract: A diaphragm pump for liquids operating by heating and vaporizing a part of the pumped liquid on the motive side of the diaphragm. A center spindle upon which the diaphragm slides is shaped to permit a limited amount of liquid to leak through into the vapor side while also permitting a release of pressure at the top end of the stroke. The spindle is also shaped to permit a suitable pressure buildup during the midportion of the stroke.

Abstract: A mass produced, easily assembled heat exchanger for use in cooling a cabinet or other enclosure by convection over both ends of fins which penetrate the wall of the enclosure. The configuration of the preferred embodiment has offset fins alternating in and out of the enclosure with the overlap at the enclosure wall and each fin acting as a spacer for the adjacent ones. An alternate embodiment uses a "U" shaped spacer to wrap around the overlapping edge of each fin, thus increasing the air flow space between fins without increasing the thickness of fins.

Abstract: A coal burning power plant which produces electricity at high efficiency and with very low levels of atmospheric contamination. A fluidized bed of limestone and coal is used to burn the coal with little air pollution, and a large quantity of specially constructed heat pipes transfer the heat to a closed cycle gas turbine with very low temperature loss. The preferred embodiments of the heat pipes are constructed with steel casing, have a thin aluminum oxide layer on their surfaces to prevent hydrogen permeation into the casing and have a plasma sprayed coating of ceramic on the portion within the fluidized bed to prevent erosion of the heat pipe casing by the solid particles within the bed.

Abstract: A mechanically assisted evaporator layer for use in both open and evacuated heat transfer systems, in which a pump and spray nozzle operate in conjunction with a sintered metal evaporator layer to reduce the temperature difference required to transfer heat across the thickness of the surface and to permit smaller temperature differences and higher power densities in transferring heat. Liquid is pumped to and sprayed from a nozzle onto the sintered metal layer to keep the entire surface wetted at all times so as to permit uniform thin film evaporation from the surface. The continual presence of liquid at the outer evaporative boundary reduces the likelihood of surface dryout while the thermal conductivity of the sintered metal promotes more effective vaporization.

Abstract: A multiple section heat pipe with swivel junctions between the sections. The individual sections are independent individual heat pipes configured to interlock with each other at rotatable joints filled with high heat conductivity liquid. The clearance between the sections is maintained small to establish capillary forces that maintain the conductive liquid in place and also to minimize the temperature differential across the rotating joint. When used in conjunction with several right angle heat pipes, the combination furnishes multiple possibilities for end to end relationship of a heat pipe system.

Abstract: A self-pumping solar liquid heating system which includes two solar collectors, a high temperature collector for generating vapor which expands and pumps fluid through the system, and a separate collector for collection of heat of utilization. A heat pipe transfers the heat from the high temperature collector to a vapor generator pump which moves the liquid in series through the second collector, a heat load and a liquid reservoir. Mechanical temperature controls are used to regulate the temperature of the heat load so no electrical power is required for the system.

Abstract: A heat pipe capillary wick constructed from a sintered metal cylinder formed in close contact with the inner diameter of the heat pipe casing, and containing longitudinal grooves on the wick's inner surface, adjacent to the vapor space. The grooves provide longitudinal capillary pumping while the high capillary pressure of the sintered wick provides liquid to fill the grooves and assure effective circumferential distribution of liquid in the heat pipe.

Abstract: An improved construction for a solar collector within a cylindrical container. The collector is a split cylindrical metal sleeve held inside another cylinder by the expansion action of a spring clip. The spring clip also expands the split sleeve so a pipe which is captured by a reentrant cavity on the outside of the sleeve is tightened within the cavity while the sleeve is tightened against the inside of the other cylinder.