HEAT EXCHANGER STAINLESS STEEL VACUUM CASTING BRAZING FILLER METAL WELDING PLANECONNECTOR AND MACHINING AND WELDING METHOD

Abstract

A stainless-steel heat-exchanger port with a braze joint interface formed from a brazing filler material by vacuum melting and molding, including: a stainless-steel port, an annular groove provided at a to-be-brazed end face of the stainless-steel port, a brazing filler material correspondingly arranged in the annular groove, and a sealing cover for preventing overflowing of the brazing filler material when melted, wherein the brazing filler material is one of copper, brass, phosphorus copper, and silver brazing filler materials. A processing method for the stainless-steel heat-exchanger port with a braze joint interface formed from the brazing filler material by vacuum melting and molding.

Claims

1. A stainless-steel heat-exchanger port with a braze joint interface formed from a brazing filler material by vacuum melting and molding, comprising: a stainless-steel port, an annular groove provided at a to-be-brazed end face of the stainless-steel port, a brazing filler material correspondingly arranged in the annular groove, and a sealing cover for preventing overflowing of the brazing filler material when melted, wherein the brazing filler material is one of copper, brass, phosphorus copper, and silver brazing filler materials.

2. The stainless-steel heat-exchanger port with a braze joint interface formed from a brazing filler material by vacuum melting and molding of claim 1, wherein a shape of a cross section of the annular groove is one of a rectangular shape, a V-shape, a semicircular shape and an oval shape.

3. The stainless-steel heat-exchanger port with a braze joint interface formed from a brazing filler material by vacuum melting and molding of claim 1, wherein the annular groove has a depth ranging from 1 mm to 5 mm.

4. The stainless-steel heat-exchanger port with a braze joint interface formed from a brazing filler material by vacuum melting and molding of claim 1, wherein two sides of the annular groove are each formed in a tapered shape for sealing.

5. The stainless-steel heat-exchanger port with a braze joint interface formed from a brazing filler material by vacuum melting and molding of claim 4, wherein the sealing cover is shaped to conform to the tapered shape of each of the two sides of the annular groove to achieve an effect of taper sealing.

6. The stainless-steel heat-exchanger port with a braze joint interface formed from a brazing filler material by vacuum melting and molding of claim 1, wherein the brazing filler material and the stainless-steel port are joined to each other by vacuum melting and molding.

7. A processing method for the stainless-steel heat-exchanger port with a braze joint interface formed from a brazing filler material by vacuum melting and molding of claim 1, comprising: providing an annular groove at a to-be-brazed end face of an stainless-steel port, and placing a brazing filler material in the annular groove; and placing a sealing cover over the brazing filler material and then heating the stainless-steel port together with the heat exchanger in a vacuum furnace to a high temperature above a melting point of the brazing filler material, so that the brazing filler material melts and fills a molding space between the annular groove and the sealing cover and is joined to the stainless-steel port heated to the high temperature, thus covering the to-be-brazed end face of the stainless-steel port with the brazing filler material.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0013] FIG. 1 is a three-dimensional view of a stainless-steel port, an annular groove and tapered sealing surfaces according to the present invention;

[0014] FIG. 2 is a sectional view of FIG. 1 according to the present invention;

[0015] FIG. 3 is a three-dimensional view of a sealing cover and tapered sealing surfaces according to the present invention;

[0016] FIG. 4 is a sectional view of FIG. 3 according to the present invention;

[0017] FIG. 5 is a schematic view of the stainless-steel port on a brazed plate heat exchanger according to the present invention;

[0018] FIG. 6 is a sectional view of an assembly of the stainless-steel port, a brazing filler material, and the sealing cover, which is going to be fed into a vacuum furnace, according to the present invention;

[0019] FIG. 7 is a sectional view of the stainless-steel port after being processed in the vacuum furnace according to the present invention;

[0020] FIG. 8 is a partial enlarged view B FIG. 6 according to the present invention;

[0021] FIG. 9 is a schematic view of the stainless-steel port with a braze joint interface formed from the brazing filler material by vacuum melting and molding after being brazed to a copper pipe according to the present invention; and

[0022] FIG. 10 is a sectional view of the stainless-steel port with the braze joint interface formed from the brazing filler material by vacuum melting and molding after being brazed to the copper pipe according to the present invention.

DETAILED DESCRIPTION

[0023] Features of the present invention and other related features are described in further detail below with an embodiment in conjunction with the accompanying drawings to facilitate understanding of the present invention by those skilled in the art:

[0024] As shown in FIGS. 1-10, reference numerals 1-11 in the figures denote the following elements, respectively: stainless-steel port 1, annular groove 2, sealing cover 3, brazed plate heat exchanger 4, brazing filler material for melting and molding 5, copper pipe 6, brazing filler material 7, inner and outer tapered sealing surfaces 8 and 9 on the stainless-steel port, and inner and outer tapered sealing surfaces 10 and 11 on the sealing cover.

[0025] Embodiment: As shown in FIGS. 1-8, this embodiment specifically relates to a stainless-steel heat-exchanger port with a braze joint interface formed from a brazing filler material by vacuum melting and molding and a processing method therefor. The port with the braze joint interface includes a stainless-steel port 1, an annular groove 2 provided on the stainless-steel port 1, a sealing cover 3, and a brazing filler material for melting and molding 5 correspondingly provided in the annular groove 2.

[0026] As shown in FIGS. 1-8, the stainless-steel port 1 in this embodiment is specifically provided on a brazed plate heat exchanger 4 and used as an inlet/outlet port. The annular groove 2 is arranged at a to-be-brazed end face of the stainless-steel port 1, and a depth of the annular groove 2 ranges from 2 mm to 5 mm. The annular groove is provided to increase a contact area between the stainless-steel port and the brazing filler material, so that a braze joint strength is enhanced. A shape of a cross section of the annular groove 2 may be one of a rectangular shape, a V-shape, a semicircular shape, and an oval shape. In this embodiment, specifically, a rectangular cross section is used. Two sides of the annular groove 2 of the stainless-steel port 1 each have a tapered shape for sealing, which conforms to a tapered shape of the sealing cover 3. Once the sealing cover 3 is placed over the annular groove 2, the brazing filler material 5 is in an enclosed state.

[0027] As shown in FIGS. 1-8, the brazing filler material for melting and molding 5 is correspondingly disposed in the annular groove 2, and the molten brazing filler material 5 fills a molding space between the annular groove 2 and the sealing cover 3, so that the to-be-brazed end face of the stainless-steel port 1, which is originally made of stainless steel, is changed to the melted and molded brazing filler material 5. The brazing filler material for melting and molding 5 in this embodiment may be made of one or more of copper, brass, phosphorus copper, and silver filler materials, which makes brazing with a copper pipe 6 to be joined subsequently very easy.

[0028] As shown in FIGS. 1-8, the processing method for the stainless-steel heat exchanger port with a braze joint interface formed from a brazing filler material by vacuum melting and molding in this embodiment specifically includes the following steps.

[0029] (1) As shown in FIGS. 1 and 2, the stainless-steel port 1 is provided with the annular groove 2, and for example, a groove with a rectangular cross section as shown in FIG. 1 is used in this embodiment.

[0030] (2) As shown in FIG. 6, it can be seen from the sectional view that assembly is done before introduction into a vacuum furnace, that is, the brazing filler material 5 is placed in the annular groove 2 of the stainless-steel port 1, and then the sealing cover 3 is placed over the annular groove 2, so that the brazing filler material 5 is placed in an enclosed molding space; and finally, the brazed plate heat exchanger 4 is put into the vacuum furnace together with the stainless-steel port 1, the sealing cover 3 and the brazing filler material 5 thereon for vacuum processing.

[0031] (3) As shown in FIG. 7, the brazing filler material 5 is heated in the vacuum furnace to a temperature above a melting point of the brazing filler material 5, so that the brazing filler material melts and fills a molding space in the annular groove, thus completing the whole processing of the stainless-steel port 1. As the entire melting and molding process is carried out in the vacuum furnace, there is no oxidation problem, which greatly improves braze joint strength, and in this way, a flat braze joint, interlace made of a brazing material or copper is formed on the to-be-brazed end face of the stainless-steel port 1.

[0032] (4) As shown in FIGS. 9 and 10, the copper pipe 6 is inserted into the stainless-steel port after being provided with the braze joint interface, and a silver brazing rod 7 is used for brazing. Brazing between two copper interfaces is very easy and provide a considerably strong braze joint strength.

[0033] This embodiment has the following beneficial effects. The brazing between a brazed plate heat exchanger and a copper pipeline becomes very easy, and the joint is firm and reliable; a brazing time can be shortened so that production efficiency can be improved; material costs can be greatly reduced; and no flux is used during processing, thus causing no air pollution. Prior brazing between two different metals (stainless steel and copper) is changed to brazing between the same metals (copper and copper), and brazing between two copper interfaces is very easy as surface adhesion force of copper is considerably strong. Or the prior brazing is changed to brazing between a brazing filler material and copper, that is, with a brazing filler material melted and molded in the groove, a user can use a brazing rod of the same brazing filler material during brazing, and as long as the temperature of copper reaches a melting point of the brazing rod, the welding rod will be melted and joined to the surface of copper and fused with the brazing filler material in the annular groove, so that the braze joint is strong, reliable and easy to achieve.