JPS5925150B2 - heat pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat pipe that is easy to manufacture and has good performance.

Conventional heat pipes employ, for example, a pipe (made of aluminum or copper) whose inner wall surface is sprayed with fine particles of dielectric material to form a wick.

However, with these heat pipes, it is difficult to uniformly form the wick on the inner wall surface of the pipe, or it is difficult to obtain a heat pipe with a desired heat transfer coefficient.

The present invention has been made in view of these drawbacks, and its feature lies in providing a heat pipe in which feather-like crystals of cupric oxide are formed as a wick on the hollow inner wall surface of a copper pipe.

That is, by making the wick into a feather shape, the liquid evaporates more easily than in the case of conventional spraying of fine particles, increases the capillary pressure, and provides a heat pipe with a good heat transfer coefficient.

An embodiment of the present invention will be described with reference to FIG. 1. Reference numeral 1 denotes a copper pipe, and feather-like crystals 3 (1 to 3 μm in length) of cupric oxide are formed as a wick on the hollow inner wall surface 2 of the pipe.

Here, in order to obtain the feather-like crystals 3 of cupric oxide, an oxidizing solution (for example, an aqueous solution of sodium chlorite and sodium hydroxide at 90° C.) may be passed through the hollow portion 4 of the copper pipe 1.

Here, since the feather-like wick has finer crystals of 1 μm or less than the fine granular wick, the liquid evaporates easily and increases the capillary pressure, resulting in a better heat transfer coefficient.

Here, a wick with a desired density is formed by adjusting the concentration, temperature, flow rate, etc. of the oxidizing liquid passed through the hollow portion 4, so that a heat pipe with a desired heat transfer coefficient can be manufactured.

Note that cuprous oxide crystals are not feather-like but fine-particle-like, which is not favorable.

As described above, according to the present invention, it is possible to easily obtain a heat pipe having a feather-like wick and having good heat transfer characteristics.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view for explaining the present invention in detail. In the figure, 2 is a copper pipe, 2 is a hollow inner wall surface of the copper pipe 1, and 3 is a crystal of cupric oxide.

Claims (1)

[Claims] 1 A heat pipe in which feather-like crystals of cupric oxide are formed on the hollow inner wall of a copper pipe.