JPS5915794A - Heat exchanger - Google Patents

Abstract

PURPOSE:To increase the degree of adherence between a heat exchanger tube and fins, by inserting a heat exchanger tube having a thin film of a nonmetallic material into fins, and melting the nonmetallic material constituting the thin film through the application of heat. CONSTITUTION:A heat exchanger tube 3 having a thin film 7 of a nonmetallic material having a melting point sufficiently lower than those of the heat exchanger tube 3 and fins 1 over the outer surface of the same is inserted into the fins 1 and heated to a temperature higher than the melting point of the nonmetallic material constituting the thin film 7 over the outer surface of the tube 3 in a heating furnace or the like. Resultantly the nonmetallic material constituting the thin film 7 over the outer surface of the tube 3 is melted, so that the fins 1 and the heat exchanger tube 3 are bonded tightly together. Therefore, it is enabled to increase the degree of adherence between the heat exchanger tube 3 and the fins 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cross-fin tube heat exchanger, and particularly to an improvement in closely fixing the fins and heat transfer tubes.

This invention relates to improving the adhesion workability between fins and heat exchanger tubes.

A conventional cross-fin tube heat exchanger is as shown in FIG. That is, (1) is the fin, (2
) is the burring part, and (3) is the heat exchanger tube. Fin (1
) are arranged in parallel, a heat transfer tube (3) is inserted, the tube is expanded, and the heat transfer tube (3) and the fin bar ring portion (2) are brought into close contact with each other.

Since the conventional cross-fin tube heat exchanger is constructed as described above, the bent portion of the flange portion at the end of the burring portion of the fin (1) is bent in order to ensure close contact with the heat transfer tube (3). When the diameter is made smaller, cracks occur and the burring part (2) breaks during tube expansion, and recently, to improve the performance of heat exchangers.

There is an increasing demand to reduce the fin spacing as much as possible,
If the distance between the fins is too small, there are problems such as cracks occurring in the flange portions, making it impossible to process them, and insufficient contact between the fins (1) and the heat transfer tubes (3).

The present invention was made in order to eliminate the drawbacks of the conventional ones as described above, and the heat transfer tube which has a thin film on the outer circumferential surface of a non-metallic material with a sufficiently low melting point is inserted into the fins and heated. The purpose of the present invention is to provide a heat exchanger that has high adhesion between the fins and heat transfer tubes and has good workability by not melting the thin nonmetallic material on the peripheral surface.

An embodiment of the present invention will be described below with reference to FIG. Second
In the figure, (7JH Fin (+1) is a thin film non-metallic material with a sufficiently lower melting point than that of +1.

In this case, fins (1) are placed on the outer peripheral surface of the conventional heat transfer tube (3).
A thin film (
Insert the heat transfer tube (3) held as 7) into the fin.

By heating in a heating furnace or the like to a temperature higher than the melting point of the thin nonmetallic material on the outer circumferential surface of the heat exchanger tube, the thin nonmetallic material (3) on the surface of the outer heat exchanger tube (3) melts, and the fins (1) and the heat exchanger tube (
3) Closely adhere. Unlike buried soil, the adhesion between the fins and the heat transfer tube (3) is maintained without expanding, and even if the interval between the fins becomes narrow, the adhesion can be maintained without fear of cracking at the burring part.

In this way, the adhesion of the two inventive systems can significantly improve the adhesion rate with the fins compared to the conventional method, contributing to improving the performance of the heat exchanger, and also reducing the spacing between the fins compared to the conventional method. Since it can be made even smaller, the performance as a heat exchanger can be easily improved.

In addition, since the tube expansion process for heat transfer tubes can be eliminated, there is no cracking or cracking in the burring part of the fins, stable quality can be obtained, and the fins and heat transfer tubes can be easily bonded together by simply heating them. Therefore, the effects of this invention are significant, such as greatly improved workability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a conventional heat exchanger, and FIG. 2 is an enlarged sectional view of a main part of a heat exchanger according to the present invention. (1) is a fin, (2) is a burring part, (3) is a heat exchanger tube 2 (7) is a thin film non-metallic material. Note that the same reference numerals in the two figures indicate the same or corresponding parts. Agent Makoto Kuzuno

Claims (1)

[Claims] A heat exchanger tube having a thin film of a non-metallic material having a melting point sufficiently lower than that of the fins and the heat exchanger tube on its outer circumferential surface, and this heat exchanger tube is inserted into the burring part of a plurality of fins, and
A heat exchanger characterized in that fins and heat transfer tubes are brought into close contact by heating the entire heat exchanger and melting a thin nonmetallic material.