JPH0780633A - Heat exchanger - Google Patents

Abstract

PURPOSE:To provide a heat exchanger in which a desired material for a tube and fin plate is selected, the low cost brazing with good workability is selected and a tube/fin plate is easily joined. CONSTITUTION:On both or one of a metal tube 4 and metal fin plate 6, the plating treatment, which is brazable as desired, is applied, both are assembled through joining by the desired brazing. Also, the treatment can be copper plating treatment, subjecting to copper brazing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a bath kettle, a water heater,
The present invention relates to a heat exchanger used for dishwashers, steamers and the like.

[0002]

2. Description of the Related Art For example, as a conventional heat exchanger for a bath kettle, a plurality of copper fin plates each having a tube insertion hole are arranged in parallel, and a tube using a copper tube is inserted into the tube insertion hole. Then, by further forming a holding hole above the tube insertion hole, inserting a welding rod into the holding hole and penetrating through a plurality of fin plates, the tube is heated in an electric reduction furnace. There is also a fin plate assembled by copper brazing all around.

[0003]

However, for example, in a conventional heat exchanger for a bathtub, since a copper tube is used as a tube, there is a problem in terms of corrosion resistance and strength. It is said that the use of copper pipes in the heat exchanger for hot water of food-related equipment has a problem in hygiene, and recently, improvements to these problems have been desired. On the other hand, it is possible to solve these problems by replacing the tube with a stainless steel tube. However, when silver brazing a tube of a stainless steel tube and a fin plate made of stainless steel or copper, for example, boric acid, Since it is necessary to perform silver brazing while applying a flux containing a to the outer surface of the tube, continuous automatic brazing cannot be performed in the electric reduction furnace, and it is necessary to perform brazing manually. Silver brazing increases the cost of the product, making it very difficult to put into practical use as a product.

Therefore, according to the present invention, although the desired material can be selected for the tube and the fin plate, it is possible to select brazing which has good workability and is inexpensive, so that the tube and the fin plate can be easily welded. The purpose is to provide a heat exchanger that can be operated.

[0005]

In order to achieve the above object, both or one of a metal tube and a metal fin plate is plated with a desired brazing material, and the desired brazing is performed. It is characterized by being assembled by welding at.

[0006] Among them, in particular, the fin-plate made of copper or copper-plated is welded to the outer surface of the stainless-steel pipe by copper-plating the outer surface of the tube by copper brazing and assembled. Can also be used.

Further, due to the effects to be described later, a holding hole for supporting the welding rod is provided in the vicinity of a supporting tube provided in parallel with the tubes plated with copper on the outer surface of the stainless steel tube so as to be spaced apart from each other and arranged in parallel. A plurality of parallel fin plates made of copper or plated with copper are packaged,
It is preferable that the tube and the fin plate are assembled by welding with copper brazing.

Particularly, it is desirable that a part of the holding hole of the fin plate is provided over the support cylinder.

[0009]

As described above, when the heat exchanger according to the present invention is used, desired brazing can be performed on one or both of the metallic tube and the metallic fin plate with good workability and at low cost. After performing various plating processes, the tube and the fin plate can be welded and assembled by desired brazing.

In particular, when the heat exchanger according to the second aspect is used, a tube plated with copper on the outer surface of the stainless steel pipe and a fin plate made of copper or plated with copper can be easily brazed. It can be assembled by welding.

Further, when the heat exchanger according to claim 3 is used, the copper-plated tubes on the outer surface of the stainless steel tube are spaced apart in parallel, and the support tube is fitted on the tubes. Alternatively, the fin plates plated with copper are packaged in parallel, the welding rods are inserted into the holding holes of the fin plates, and the whole is heated by putting it in an electric reduction furnace. Copper brazing is performed over the entire circumference in the gap between the outer surface of the tube and the inner surface of the support tube of the fin plate made of copper or copper-plated, and the fin plate is fixed to the tube. , The entire heat exchanger can be assembled.

When the heat exchanger according to claim 4 is used, when the welding rod supported by the holding hole melts, it flows into the entire inner surface of the supporting cylinder through the holding hole provided in the supporting cylinder and is brazed. Is done.

[0013]

The details of the present invention will be described with reference to the embodiments shown in the drawings. FIG. 1 is an explanatory sectional view showing an essential part of a bathtub using a heat exchanger of a representative embodiment, and FIGS. 2 to 6 are related to description of a heat exchanger of a representative embodiment.

As shown in FIG. 1, in the bath cauldron A, the cauldron body 1 has a double structure of an inner case 1a and an outer case 1b, the inlet tube 2 and the outlet tube 3 are connected to the bathtub, and the main body 1 Inner body 1a
The heat exchanger B is attached to the inside of the bath, and the heat in the bath is circulated and warmed by heating the entire heat exchanger B by the thermal power of the burner from below.

In the heat exchanger B, as shown in FIGS. 3 and 4, the tubes 4 are spaced apart and arranged in parallel, and a fin plate 6 having a plurality of tube insertion holes 5 is externally arranged in parallel.
The tube 4 and the fin plate 6 are assembled by brazing and welding the entire circumference.

The tube 4 is formed by immersing the stainless steel pipe 7 at both ends with caps fitted and closing it, immersing it in a copper plating tank for copper plating, and then removing the caps at both ends. As in No. 2, only the outer surface of the stainless steel pipe 7 is subjected to copper plating 8 treatment.

The fin plate 6 has a tube insertion hole 5 which is slightly larger than the outer diameter of the tube 4 in the plate body 9.
A support cylinder 10 having a. Is extended to the back side, and a holding hole 12 for supporting a welding rod 11 (generally also called a brazing material) is formed at the upper end of the tube insertion hole 5, for example, a stainless steel plate or the like. The copper plating 8 is applied to the entire surface including the inner surface of the support cylinder 10. The fin plate 6 is
It is possible to simply use a copper plate, and it is possible to provide a copper plate that is superior in heat transfer and inexpensive in cost. Further, in the illustrated fin plate 6, the holding hole 12 is formed in the plate body 9 as shown in FIG.
The lower end of the holding hole 12 is formed so as to cover a part 10a of the support cylinder 10. Therefore, when the welding rod 11 is melted, it flows into the entire inner surface of the supporting cylinder 10 through the holding hole 10a provided in a part of the supporting cylinder 10 for brazing, so that the fin plate 6 is securely welded to the tube 4. Is done.

Then, as shown in FIG. 5 (a), the tubes 4 are inserted into the tube insertion holes 5 so that the plurality of fin plates 6 are spaced apart and arranged in parallel, and the tubes are fixed by using a jig or the like. 4 is expanded to set the clearance between the inner surface of the support cylinder 10 and the tube 4 to about 0.025 to 0.1 mm, and then the welding rod 11 for copper brazing is further inserted into the holding hole 12 ... In the electric reduction furnace. When it is put into a heating rod and heated, as shown in Fig. 5 (b), the welding rod
11 is melted and only the outer surface of the stainless steel tube 7 is copper-plated 8 The outer surface of the tube 4 and the inner surface of the support tube 10 of the fin plate 6 which is copper-plated 8 processed on a stainless steel plate, etc. Copper brazing all around
11a is performed, and the tube 4
· The fin plate 6 is fixed to the heat exchanger B
The whole can be assembled. That is, copper brazing can be performed only by performing copper plating on the outer surface of the tube 4 and copper plating on the surface of the fin plate 6, or by using the fin plate 6 made of copper.

In the heat exchanger A described above, the outer surface of the stainless steel pipe or the stainless steel plate is plated, but various metals can be used depending on the application, and the surface is plated. It is also possible to weld by silver brazing using silver plating.Otherwise, by using brass brazing, nickel silver brazing, gold brazing, etc. and performing a plating treatment according to it, various different metals It is possible to easily perform brazing, or brazing metal to metal, which has not heretofore been easily possible. It is also possible to perform brazing by plating only one of the tube 4 and the fin plate 6.

In the heat exchanger A described above, the bath pot A
However, it is not particularly limited, and it can be used for heat exchangers for water heaters, dishwashers, steamers, etc., or heat exchangers in various fields. Further, to add to the above, by using the above-described technique, not only the heat exchanger but also various metals can be joined.

As described above, according to the heat exchanger A, as the tube 4, a stainless steel tube 7 whose outer surface is copper-plated 8 only is used, and as the fin plate 6, a stainless steel plate or the like is copper-plated 8 treated. Since it is not necessary to perform brazing while applying the flux to the outer surface of the tube 4 by using the material, it is possible to easily weld and assemble the tube 4 by simply putting it in an electric reduction furnace and heating the whole. So with these new methods,
It becomes possible to use a stainless steel tube 7 for the tube 4 of the heat exchanger A in the bathtub A, which is superior in strength to the tube 4 that uses a conventional copper tube and also significantly in hygiene. It can be improved, and depending on the fluid inside, it also has excellent corrosion resistance.

[0022]

Since the present invention is configured as described above, it has the following effects. According to the heat exchanger of claim 1, both or one of the metal tubes and the fin plate made of metal are subjected to a plating process that allows a desired brazing process with good workability and at low cost, and then, Since the tube and fin plate can be assembled by welding with the desired brazing, for example, by performing a copper plating process that enables copper brazing, it is possible to easily braze without applying flux to the outer surface of the tube. be able to.

According to the heat exchanger of claim 2, the stainless steel tube and the fin plate made of copper or stainless steel plate are welded by copper brazing instead of silver brazing by plating. Because it can be done easily, in addition to being easy to do, the price can be significantly reduced. For example, as in the heat exchanger of a conventional bath kettle, a stainless steel tube can be used instead of a copper tube for the tube, which makes it excellent in strength and can significantly improve hygiene. Depending on the fluid inside, it also has excellent corrosion resistance.

According to the heat exchanger of the third aspect of the present invention, the outer surface of the stainless steel pipe is provided with the copper-plated tubes which are arranged in parallel with each other, and the support cylinder is externally fitted to the tubes to be made of copper or copper-plated. A fin plate that has been subjected to heat treatment is installed in parallel, the welding rod is inserted into the holding hole of the fin plate, put into the electric reduction furnace, and the whole is heated. The welding rod melts and the tube is plated with copper. Copper brazing is performed over the entire circumference in the gap between the outer surface and the inner surface of the support tube of the fin plate made of copper or plated with copper, the fin plate is fixed to the tube, and the heat exchanger is fixed. The whole can be assembled.

According to the heat exchanger of the fourth aspect, when the welding rod supported by the holding hole is melted, the welding rod flows into the entire inner surface of the supporting cylinder through the holding hole provided in the supporting cylinder for brazing. The fin plate is reliably welded to the tube.

[Brief description of drawings]

FIG. 1 is an explanatory cross-sectional view showing a main part of a bath cooker using a heat exchanger of a representative embodiment.

FIG. 2 is a conceptual explanatory view showing a disassembled state of the heat exchanger before assembly.

FIG. 3 is a plan view of the heat exchanger.

FIG. 4 is a front view of the heat exchanger.

5A is a vertical cross-sectional view showing a main part of the heat exchanger before brazing; FIG. 5B is a vertical cross-sectional view showing a main part of the heat exchanger after brazing.

FIG. 6 is an enlarged sectional view of an essential part showing a positional relationship between a tube and a fin plate.

[Explanation of symbols]

 A bath kettle B heat exchanger 1 kettle body 2 inlet pipe 3 outlet pipe 4 tube 5 tube insertion hole 6 fin plate 7 stainless steel pipe 8 copper plating 9 plate body 10 support cylinder 11 welding rod 12 holding hole 13 gap

Claims (4)

[Claims] 1. A metal tube and a metal fin plate, or one of them is subjected to a plating treatment capable of desired brazing, and is welded and assembled by desired brazing. Heat exchanger. 2. A heat exchanger characterized in that a fin plate made of copper or plated with copper is welded by copper brazing to the surface of a tube obtained by plating the outer surface of a stainless steel pipe with copper, and assembled. 3. A copper-made tube having copper-plated tubes on the outer surface of a stainless steel pipe, which are arranged in parallel at a distance from each other, and a holding hole for supporting a welding rod is formed in the vicinity of a support cylinder provided continuously to the tube insertion hole. Alternatively, a heat exchanger characterized in that a plurality of fin plates plated with copper are packaged in parallel and the tubes and the fin plates are welded and assembled by copper brazing. 4. The heat exchanger according to claim 3, wherein a part of the holding hole of the fin plate is provided over the support cylinder.