JPH06100434B2 - Plate type heat exchanger - Google Patents

Description

Description: FIELD OF THE INVENTION This invention relates to improvements in plate heat exchangers.

2. Description of the Related Art A plate-type heat exchanger is formed by stacking a plurality of plates to form a passage for a heat medium between the plates, and heat is exchanged between two heat mediums flowing through the plates.

Conventionally, in order to hold the plate in an appropriate position and overcome the force generated by the pressure of the heat medium, the plate group is usually clamped and clamped between a pair of frames. In view of the fact that the frame occupies a considerably large proportion in the whole heat exchanger in terms of weight and price, a plate heat exchanger in which the use of the frame is abolished or made thin has been proposed. That is, as shown in FIG. 3, adjacent plates (1a) and (1b) are permanently connected to each other at their outer peripheral edges (4) and around the entrances (2a) and (2b) of the heat medium (5). It is a united joint.

Problems to be Solved by the Invention Permanent joining of plates is performed by brazing, soldering or the like, but in any case, in order to secure desired rigidity, the joining portion needs to be tight and tight without gaps. The joint is not only required to be stable and reliable in terms of strength, but is also required to be watertight or airtight in terms of the function of the heat exchanger, and it is not allowed that there is a gap in the joint. For example, if there is a gap in the joint part of the peripheral edge of the plate, the heat medium leaks out of the device. Further, if there is a gap in the joint around the medium inlet / outlet, the medium passages that are adjacent to each other are communicated with each other via the plate, and the heat mediums inside are allowed to mix with each other.

For example, as shown by an imaginary line in FIG. 3, distortion is likely to occur particularly around the medium entrance and exit, so that it is difficult to perform good joining such as brazing. Moreover, since plates are usually manufactured by press molding, the generation of strains is inevitable.

The main object of the present invention is to eliminate the above-mentioned drawbacks in a plate heat exchanger of the type in which adjacent plates are permanently joined together. That is, the present invention provides a structure of a plate type heat exchanger of this kind which enables a reliable and leak-free joining, particularly at the joint around the medium inlet and outlet.

Means for Solving the Problems In order to solve the above problems, according to the present invention, in a plate heat exchanger in which adjacent plates are permanently joined to each other around an outer peripheral edge and a medium inlet / outlet port, A step surrounding the medium inlet / outlet is provided in the joint around the medium inlet / outlet, and the rising portion of one plate and the rising portion of the other plate are fitted in a nesting manner to form the upper end of the rising portion of the joint surface. It forms a puddle.

Action When joining adjacent plates, the molten brazing material spreads between the joining surfaces, and at the stepped portion where the joining surface rises, the brazing material rises due to the capillary phenomenon to form a brazing pool at the upper end. This braze reservoir serves to seal the joint and provide more complete media leakage protection after brazing.

Embodiment Referring to FIG. 1 and FIG. 2 showing an embodiment of the present invention, a plate heat exchanger has a plurality of switches (11a) (1).
1b) are laminated and heat medium passages (A) are placed between the plates.
It can be seen that it is a product of (B). Adjacent plates are permanently joined together at least at their perimeter edges (14) and around the perimeter of the medium entrance (15).

Medium entrance (12a) (12b) of each plate (11a) (11b)
Steps (17a) (17b) surrounding the medium entrances (12a) (12b) are provided around the. The steps may be concentrically provided in two or more steps, or may be circular (second
In addition to the above, it can be polygonal. Further, the cross-sectional shape may be stepwise as shown in FIG. 1 (FIG. 1) or may be corrugated.

By providing the steps (17a) and (17b), the adjacent plates (11a) and (11b) are separated from each other by the outer peripheral edge (14) and the steps (17a) (1).
7b) Nested with both parts. Therefore, higher rigidity can be imparted to the plate heat exchanger.

However, when joining the adjacent plates, the molten brazing filler metal spreads between the joint surfaces, and even at the part where the joint surface stands up, it rises due to the capillary phenomenon between the joint surfaces and the braze deposit (1
8) to form. The braze reservoir (18) helps to seal the joint and provide more complete media leakage protection after brazing. In particular, even if the plate is distorted, fitting of the adjacent plates is always ensured in the steps (17a) and (17b), so that leak-free and reliable joining can be performed in the parts.

EFFECTS OF THE INVENTION According to the present invention, since the step is provided around the medium entrance / exit where the strain is likely to occur, the adjacent plates are fitted in the step portion in a nested manner, and the rising portion of one plate in the step portion. At the joining surface portion that is erected between and the rising portion of the other plate, the brazing material rises due to the capillary phenomenon to form a brazing pool at the upper end. This braze reservoir seals the joints and makes media leakage prevention even more complete after brazing. Therefore, a leak-free and reliable joint can be obtained.

Further, since the step portion is provided and the adjacent plates are fitted in the step portion in a nested manner,
The positioning of the plates and the joining by brazing, etc. are made easy and reliable, and the strength of the plate itself is not only improved by the existence of the step, but also the adjacent plates are fitted in the stepped part in a nesting manner, so that the plate concerned This has a great effect such that the rigidity of the whole type heat exchanger is further increased.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a plate heat exchanger according to an embodiment of the present invention, which is taken along the line II of FIG. FIG. 2 is a plan view of the plate. FIG. 3 is a sectional view of an essential part similar to FIG. 1 showing a conventional example. (11a) (11b) ... plate, (12a) (12b) ... medium entrance / exit, (15a) (15b) ... joint, (17a) (17b) ...
… Step, (18) …… Wax pool.

Claims (1)

[Claims] 1. A plate-type heat exchanger in which adjacent plates are permanently joined to each other around an outer peripheral edge and a medium inlet / outlet, and a step surrounding the medium inlet / outlet at a joint portion around the medium inlet / outlet of each plate. And a rising part of one plate and a rising part of the other plate are fitted in a nested manner, and a brazing pool is formed at the upper end of the rising part of the joint surface. .