HEAT PIPES

• US 3,700,028 A
• Filed: 12/10/1970
• Issued: 10/24/1972
• Est. Priority Date: 12/10/1970
• Status: Expired due to Term

• Current Assignee: Don W. Noren
• Original Assignee: Don W. Noren
• Inventors: Noren, Don W.
• Primary Examiner(s): Davis, Jr., Albert W.
• Application Number:
  US05/096,836
• Time in Patent Office: 684 Days
• Field of Search: 165/32,105
• US Class Current: 165/272
• CPC Class Codes: F28D 15/046 characterised by the material or the construction of the capillary structure

Abstract

The specification and drawings disclose two embodiments of heat pipe structures arranged to readily conduct heat in one direction and conduct only a limited amount of heat in the opposite direction. In both embodiments, the heat pipe is shown as comprising a hollow, sealed tube having wick material positioned in engagement with selected portions of the inner surface. A vaporizable fluid is placed in the tube in an amount sufficient to wet the wick. In one embodiment, the wick extends over and is in engagement with only those portions of the wall surface from which it is desired to transfer heat. The other portions of the wall surface are bare. Consequently, fluid in the wick can be vaporized and flow to the bare wall portion for condensation. However, if the bare wall portions are at a higher temperature, heat cannot be transferred to the wicked portion except by conduction through the tube wall. In the second embodiment, the entire inner surface is covered by a wick but in certain areas, the wick is spaced from the surface. The spaced areas function in the manner of the bare areas of the first embodiment but allow the unit to be used in any orientation since droplet formation in the spaced wick areas permit the droplets to engage the spaced wick for capillary flow to the heated wick portion.

Claims

1. A heat pipe assembly adapted to transmit heat primarily in one direction comprising:

a sealed, fluid imperviOus body having a hollow interior;

a wick member adapted to conduct fluid by capillary action positioned within said body with a portion of said wick in close engagement with the interior surfaces of said inner walls and the remaining portion being spaced from said wall a distance such that fluid condensing on the wall adjacent said spaced portion will not engage the spaced wick until it has formed substantial sized droplets.

2. The heat pipe as defined in claim 1 wherein said wick member is substantially continuous throughout the interior of said body and spaced from the inner wall of said body throughout an extent of greater than 10% of the internal wall surface.

3. A heat pipe as defined in claim 1 wherein said body comprises a first sealed tubular member and wherein said wick member comprises a second tubular member having portions of at least two different outer diameters including a first outer diameter to closely engage the interior surface of said body and a second outer diameter to be spaced from interior surface of said body.

4. A heat pipe as defined in claim 1 wherein said body is formed from metal having a relatively thin wall.