JPH089097B2 - Laminated brazing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for brazing a laminated body used for manufacturing a plate fin type heat exchanger.

[Prior Art] A plate fin type heat exchanger has a structure in which fluid passages having corrugated fins are laminated in a plurality of stages, and is manufactured by brazing. A method of manufacturing the plate fin type heat exchanger by brazing will be described with reference to the heat exchangers of FIGS. 4 and 5. FIG. 4 is a plan view of the heat exchanger, and FIG. 5 is a sectional view taken along the line BB of FIG.

The heat exchanger has a large number of tube plates 2, 2 which are stacked between the upper and lower end plates 1, 1 with a space therebetween. The tube plates 2, 2 ... Are made up of two adjacent plates 2, 2 as a set, and both sides of the plates 2, 2 are closed so that a fluid passage is formed between the plates 2, 2. A first corrugated fin 3a is disposed between the two plates 2 and 2 in each set, and a second fluid passage formed between each set has a second corrugated fin 2a.
The corrugated fins 3b of FIG.

The heat exchanger also has a flow path 5 formed by penetrating the tube plates 2, 2, ... In the stacking direction at two corners located on the diagonal of the end plates 1, 1. Around the flow path 5, a pair of tube plates 2 and 2 are bent toward the opposite side and come into contact with each other, so that the tube plates 2 and 2 are closed. At the edge of the tube plate located outside the flow path 5, in order to close the gap between each set, two tube plates facing each other in the adjacent set are bent and contact to the opposite side, and Accordingly, an arc-shaped space 6 that surrounds the flow path 5 is formed between the pair of tube plates 2, 2.

One of the fluids A, which is heat-exchanged, flows into the fluid passage in which the first corrugated fins 3a are arranged from one side surface of the heat exchanger, and flows out to the outside from the other side surface. The other fluid B flows into the heat exchanger from the header pipe 4 which is erected on one side of the upper end plate 1 on the diagonal line. The fluid B that has flowed into the heat exchanger flows into the fluid passage provided with the second corrugated fins 3b from the flow passage 5 that penetrates the tube plates 2, 2, ... After passing through the passage in the diagonal direction, it flows out to the outside via the flow path 5 and the header pipe 4 which are also provided at the other end portion on the diagonal line.

In the plate fin type heat exchanger having such a structure, the tube plates 2, 2 ... And the corrugated fins 3a, 3b ... are laminated between the upper and lower end plates 1, 1 through the brazing material, and the lamination direction is formed in the laminated body. It is manufactured by heating the laminate above the melting point of the brazing material in a vacuum while applying a compressive load. When the heat exchanger is used for high temperature and high pressure, the heat exchanger is made of stainless steel, and a high melting point brazing material is used for the heat exchanger made of stainless steel, so the heating temperature is 1200 ~ 1300
℃ and high.

[Problems to be Solved by the Invention]

In the production of the heat exchanger by such brazing, a compressive load is applied in the laminating direction of the laminated body, so that the portions where the corrugated fins 3a, 3b ... Are interposed between the tube plates 2, 2, Since a sufficient compressive load is transmitted in the stacking direction via the corrugated fins 3a, 3b ..., The tube plates 2, 2 ... And the corrugated fins 3a, 3b ... Are brazed to each other with a predetermined strength.

However, in the outer edge portion of the flow path 5 in which the corrugated fins 3a, 3b ... Are not interposed between the tube plates 2, 2 ,.
Since a set of tube plates 2, 2 joined to each other are stacked in a plurality of stages with a space 6 formed between each set, a compressive load applied in the stacking direction is applied to the tube plates 2, 2. Not fully transmitted between the two. For this reason, there is a high risk that the tube plates 2, 2 ... Will have poor joints at this portion.

In order to solve this problem, it is conceivable to interpose a spacer in the space 6, but the spacer is formed by the corrugated fins 3a, 3
In the case of a metal such as b, the spacer may be bonded to the tube plates 2, 2 by the brazing material. Also,
When the heat exchanger is made of stainless steel, since the heating temperature is high, softening deformation may occur depending on the type of metal forming the spacer, and the function as the spacer may not be achieved.

An object of the present invention is to reliably braze two tube plates brazed together, regardless of the heating temperature, even at the outer edge of the flow path in which a plurality of layers are stacked with a space between them. It is to provide a method for brazing a laminate that can be brazed.

[Means for solving the problem]

According to the brazing method of the present invention, ceramic-made spacers are press-fitted into each arc-shaped space formed at the outer edge of the flow path at intervals in the circumferential direction to perform brazing. Is to be removed.

The spacers may be a pair of wedge-shaped members having inclined surfaces on mutually opposing surfaces.

[Action]

The ceramic spacer has low adhesiveness to the brazing material, and does not melt even when given a high heating temperature such as when manufacturing a stainless steel heat exchanger, and a large load is applied in that case. Deformation does not occur even if it receives.

Therefore, a pair of tube plates to be brazed are stacked in a plurality of stages with a space between each pair, and at the outer end of the flow path, a spacer made of ceramics is interposed in each space to increase the temperature. Even under heating, sufficient adhesion is given between the stack of tube plates. as a result,
Good brazing with little deformation is performed.

Further, since the space is arcuate and has a small depth, the spacer can be easily removed from the space after brazing, and the spacer can be reused.

When the spacer is a set of wedge-shaped members, the spacer can be easily pushed into the space with a slight force.

〔Example〕

Hereinafter, the case where the embodiment of the method of the present invention is applied to the manufacture of the plate fin type heat exchanger will be described with reference to FIGS. 1 to 3.

FIG. 1 is a plan view showing a part of a plate fin type heat exchanger manufactured by the method of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is used for the method. It is a perspective view of the spacer to be.

The structure of the plate fin type heat exchanger is as described above, and at the outer edge of the flow path 5, a pair of tube plates 2, 2 brazed with each other forms an arc-shaped space 6 surrounding the flow path 5. It is laminated in multiple stages via.

In the production of the heat exchanger, the tube plates 2, 2 ... And the corrugated fins 3a, 3b ... are laminated between the upper and lower end plates 1, 1 with the brazing material interposed therebetween, and a compressive load in the laminating direction is applied to the laminated body. In this state, the laminate is constrained. As a result, the members are brought into close contact with each other with a sufficient load at the portions where the corrugated fins 3a, 3b ... Are interposed between the tube plates 2, 2. However, at the outer edge of the flow path 5 communicating with the header pipe 4, an arc-shaped space 6 is formed between each pair of tube plates 2, 2 which are brazed to each other. Therefore, the tube plate 2,2
Not enough adhesion is added between them.

Therefore, as shown in FIGS. 1 and 2, a plurality of arc-shaped spaces 6, 6 formed on the outer side of the flow path 5 are made of ceramics with a circumferential gap for each step. Insert the spacers 7, 7… from the outside.

Each spacer 7, as shown in FIGS. 2 and 3,
Two wedge-shaped members 7a, 7b are used one above the other, and one of the mutually opposing surfaces is an inclined surface 8a inclined so that the wall thickness gradually increases from one end to the other in the insertion direction. On the other hand, the other mutually opposing surface is an inclined surface 8b that is inclined so that the wall thickness gradually increases from the other end in the insertion direction to the one end.

When the spacer 7 is inserted into the space 6, the wedge-shaped members 7a and 7b are displaced in the direction in which the total thickness of the spacer 7 is reduced and then inserted into the space 6. Then, the wedge-shaped members 7a and 7b protruding outward are pushed inward. As a result, the total thickness of the spacer 7 is increased, and a sufficient adhesive force is given between the two tube plates 2 and 2.

When the spacers 7, 7 ... Are attached to the laminated body, the laminated body is heated in vacuum to a temperature equal to or higher than the melting point of the brazing material. When heating is completed and the laminate is cooled sufficiently, spacers are removed from the laminate.
Remove 7,7 ...

The ceramics forming the spacer 7 is, for example, Al ₂ O ₃ ,
Examples thereof include Si ₃ N ₄ and SiC.

The size of the spacer 7 is appropriately determined according to the size of the space 6 to be inserted.

When the heat exchanger is made of stainless steel, powdered nickel or the like is used as the brazing material, and the brazing temperature is about 1200 to 1300 ° C.

When the plate fin type heat exchanger is manufactured by the brazing method as described above, the flow paths 5 in which the tube plates 2 to be brazed with each other are stacked in a plurality of stages through the mountain-shaped spaces 6 Even at the outer edge of the tube plate 2,
Similar to the portion where the corrugated fins 3a and 3b are interposed between the two members, the respective members are brought into close contact with each other with a sufficient load. Moreover, the spacer 7 inserted into the space 6 does not deform even when exposed to a high brazing temperature such as when manufacturing a heat exchanger made of stainless steel. Accordingly, the outer edge of the flow path 5 is brazed without deformation like the other portions.

Further, since the space 7 has a weak adhesive force to the brazing material, there is no possibility of being brazed to the heat exchanger, and the depth of the arc-shaped space 6 is small, which facilitates removal from the heat exchanger. is there. Spacer 7 removed
Can be reused repeatedly.

Although the spacer 7 is wedge-shaped in the above embodiment, it is needless to say that it is not limited to this.

〔The invention's effect〕

As is clear from the above description, the laminated body brazing method of the present invention uses a spacer made of ceramics at the outer edge of the flow path to which adhesion is hard to be applied. Also in the manufacture of the plate fin type heat exchanger, each part of the heat exchanger can be brazed reliably without deformation and the quality thereof is improved. Further, the spacer is not brazed and can be easily removed, and the spacer cost can be reduced by reuse.

When the spacers are a set of wedge-shaped members, the attachment and detachment thereof is particularly easy, and even when a large number of spacers are used, there is an advantage that the attachment and detachment does not require a long time.

[Brief description of drawings]

FIG. 1 is a plan view of an essential part of a plate fin type heat exchanger showing an example of the method of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is used for the method. A perspective view of the spacer,
FIG. 4 is a plan view of the plate fin type heat exchanger, and FIG. 5 is a sectional view taken along the line BB of FIG. 1: end plate, 2: tube plate, 3a, 3b: corrugated fins, 4: header pipe, 5: flow path, 6: space, 7: spacer, 7a, 7b: wedge-shaped member, 8a, 8b: inclined surface.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaaki Kuno 2-6, Nishi-Nagasumotodori, Amagasaki-shi, Hyogo Sumitomo Precision Industries Co., Ltd. (56) Reference JP-A-52-30247 (JP, A) Actual Kai 63-76367 (JP, U)

Claims (2)

[Claims] 1. A unit formed by sandwiching a first corrugated fin (3a) between two tube plates (2, 2) is a second unit.
And the flow path (5) penetrating in the stacking direction is formed at the corner of the unit while being stacked through the corrugated fins (3b) of
The two tube plates (2, 2) in the unit are bent around the flow path (5) toward the opposite side to make contact with each other, and the tube plates (2, 2) are closed.
Two tube plates (2, 2) in the unit are formed by bending and contacting two tube plates facing each other of an adjacent unit at the edge of the unit located outside the flow path (5) to the opposite side. A laminated body brazing method used for manufacturing a plate fin type heat exchanger in which an arcuate space (6) surrounding a flow path (5) is formed, the tube plate and the brazing material being interposed by a brazing material. The outer edge of the flow path (5) is used for brazing by heating the laminated body above the melting point of the brazing material while applying a compressive load in the laminating direction to the laminated body formed by alternately laminating the corrugated fins. A plurality of ceramic spacers (7) press-fitted at intervals in the circumferential direction are interposed in an arc-shaped space (6) formed in the portion, and the spacers (7) are removed from the space (6) after brazing. Product characterized by Layer brazing method. 2. The method for brazing a laminate according to claim 1, wherein the spacers (7) are a set of wedge-shaped members having inclined surfaces on mutually opposing surfaces.