Abstract: A heat pipe whose fluid can be repeatedly frozen and thawed without damage to the casing. An additional part is added to a conventional heat pipe. This addition is a simple porous structure, such as a cylinder, self-supporting and free standing, which is dimensioned with its diameter not spanning the inside transverse dimension of the casing, and with its length surpassing the depth of maximum liquid.

Abstract: A closely coupled two phase heat exchanger. The heat is transferred between gas streams by multiple intermediate fluid paths. Each of the several intermediate fluid paths passes alternately between the hot and the cold gas stream many times during its travel from the pump. The heat exchanger is designed so that the intermediate fluid vaporizes in the hot and condenses in the cold section each time, thereby minimizing the quantity of liquid necessary to transfer the heat. The pumping action for the intermediate fluid exchanger is accomplished by either mechanical or vapor pumps. An added feature of the heat exchanger is automatic control of the minimum temperature to which the hot gas is cooled. This is accomplished by shutting off one of several intermediate fluid paths at the cool end of the gas being cooled. The shutoff is accomplished either on the basis of temperature of the cooled gas or on the formation of condensates at the cool end of the gas flow path.

Abstract: A heat pipe which can be rolled up for storage and automatically deploys when heat is applied. Two highly flexible parallel sheets are bonded together at their edges, thus permitting compact rolled storage. The inside portions of the joined edges form creases which act as capillary channels to move the heat exchange liquid from the condenser to the evaporator. A further embodiment involves multiple longitudinal cells which yield many more capillary channels and increases the structural strength of the deployed heat pipe, while maintaining the large surface area for heat transfer.

Abstract: A high performance heat pipe and the method for constructing it. A unique wick structure of sintered metal is formed directly into the heat pipe casing and contains simultaneously formed tunnels which permit the flow of large quantities of liquid with low pressure loss. A method of constructing a hybrid structure with heat pipe sections at both ends of a section used to transport the internal liquid and vapor over long distances is also included.

Abstract: A heat pipe wick which can survive freezing of the heat transfer fluid within the heat pipe and return to full operation automatically. A flexible high lift wick is used with a limited liquid inventory to prevent damage from freezing. The limited amount of liquid is completely retained in the wick at all times by capillary forces preventing puddling at the lowest point in the heat pipe, thus avoiding damage to the casing by expansion.

Abstract: A process for producing liquid compatible metals and a heat pipe manufactured by that process. One example of the process comprises the formation of an aluminum oxide surface layer on an aluminum bearing steel alloy by heating the steel to a high temperature in an oxidizing environment.