JPH0989487A - Plate heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of a passage hole gasket at a gasket side passage hole and to stabilize the fluid sealing property thereof by providing a groove for exclusive use of a passage hole gasket at a location between a gasket side passage hole of plate and a heat transfer surface so as to be spaced apart from a welding line. SOLUTION: A groove 9 for exclusive use of a passage hole gasket is formed at a location between a gasket side passage hole 4 of a plate 5 forming a cassette 1 so as to be spaced apart from a weld line W and a passage hole gasket 8 for fluid seal of the hole 4 between the plate cassette 1 and a frame 7 is mounted to the groove 9. Since the passage hole gasket is mounted to the groove 9 having a flat bottom being free from welding beads, scratches or cracks are prevented from being produced due to welding beads on the surface of the passage hole gasket, and sealing property at the gasket side passage hole between the cassette and the frame can be stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to stacking a plurality of plate cassettes having two plates welded to each other via a gasket and tightening the plate cassettes from both sides with two thick plate frames. The present invention relates to a welding-type plate heat exchanger in which welding-side flow passages fluid-sealed by welding and gasket-side flow passages fluid-sealed by a gasket are alternately formed.

[0002]

2. Description of the Related Art Generally, a welding type plate heat exchanger is constructed by stacking a plurality of plate cassettes (1) as shown in FIG.

The plate cassette (1) is composed of a rectangular flat plate, and has a corrugated heat transfer surface (2) on the surface thereof, and welding side passage holes (3) serving as fluid inlets and outlets at four corners. ) And the gasket-side passage hole (4) are opened as a pair, respectively, and the heat transfer surface (2) and the gasket-side passage hole (4) communicate with each other around the substantially trapezoidal region and the welding-side passage hole (3). Plates (5) having gasket grooves (indicated by the one-dot chain line in FIG. 3) surrounding the periphery of the plate are polymerized as a set of two plates, which are along the welding line (W) shown in the dotted line in FIG. Such as laser welding so that the welding side passage hole (3) communicates with the heat transfer surface (2) and the gasket side passage hole (4) is doubly blocked from the heat transfer surface (2). It is welded airtightly with the plate (5) by the welding line (W). Forming a body seal weld side channel.

And, in this plate cassette (1),
The gasket-side passage hole (4) is communicated with the heat transfer surface (2) along the gasket line (G) indicated by the one-dot chain line in FIG. 3, and the welding-side passage hole (3) is transmitted. A gasket (6) made of a heat-resistant elastic material such as synthetic rubber is attached so as to double-shield the hot surface (2),
A plurality of this is laminated and two frames (7)
By tightening from both sides with the gaskets, the gasket-side flow passage that is fluid-sealed by the gasket (6) is formed between the plate cassettes (1), and the welding-side flow passage and the gasket-side flow passage are alternately formed. It constitutes a welded plate heat exchanger.

In the above-mentioned welded plate type heat exchanger, the welding side fluid and the gasket side fluid are alternately circulated in the welding side passage and the gasket side passage so that heat is exchanged between the two fluids. ing.

In this type of welded plate heat exchanger, the fluid seal of the gasket side passage hole (4) between the plate cassette (1) and the frame (7) is as shown in FIG. ) Is formed through a through hole gasket (8) fitted in a welding line groove surrounding the gasket side passage hole (4) of the plate (5).

By the way, the seal height between the plate cassette (1) and the frame (7) in the above-mentioned welding type plate heat exchanger is half the seal height between the plate cassettes (1) and the above-mentioned flow hole. The thickness of the gasket (8) is also about half that of the gasket (6) interposed between the plate cassettes (1) in order to obtain an appropriate compression rate.

[0008]

By the way, the through hole gasket (8) for fluid-sealing the gasket side passage hole (4) between the plate cassette (1) and the frame (7) in the welding type plate heat exchanger is provided. , A welding line groove surrounding the gasket-side passage hole (4) of the plate (5) forming the plate cassette (1), the welding line groove being formed when forming the plate cassette (1). The groove bottoms are welded together by laser welding or the like. Therefore, the groove bottom of the welding line groove surrounding the gasket-side passage hole (4) is formed with unevenness due to the welding bead.

Therefore, when the passage hole gasket (8) is mounted in the welding line groove surrounding the gasket side passage hole (4) in such a state, the plate heat exchanger is tightened or pressurized. By being heated, the surface of the passage hole gasket (8) is likely to be scratched or cracked due to the contact with the groove bottom of the welding line groove in which the unevenness due to the welding beat is formed. In particular, since the passage hole gasket (8) is as thin as about half of the gasket (6) interposed between the plate cassettes (1), the compression margin is small,
The conformability of the shape in the thickness direction due to the unevenness of the welding of the groove bottom of the welding line groove is poor. As a result, the life of the passage hole gasket (8) is extremely shortened, or the fluid sealability of the passage hole gasket (8) in the gasket side passage hole (4) is deteriorated, resulting in the plate cassette (1) and the frame (7). There was a problem of fluid leakage between the two.

An object of the present invention is to extend the service life of the passage hole gasket in the gasket side passage hole between the plate cassette and the frame and to stabilize the fluid sealability.

[0011]

In order to achieve the above-mentioned object, the present invention has a heat transfer surface at the center and a welding-side passage hole and a gasket-side passage hole which serve as fluid inlets and outlets at four corners. Plates each having a pair of openings and forming gasket grooves surrounding the substantially trapezoidal region where the heat transfer surface communicates with the gasket-side passage hole and the periphery of the welding-side passage hole are superposed as one set. , The welding bottom passage is communicated with the heat transfer surface, and the groove bottoms of the plates are welded airtightly along a welding line that double-blocks the gasket side passage hole from the heat transfer surface to form a plate cassette. In the plate heat exchanger in which a plurality of plate cassettes are laminated with a gasket interposed therebetween, and two thick plate frames are tightened from both sides to alternately form welding side flow passages and gasket side flow passages, Pre The plate for forming the cassette is formed with a groove dedicated to the passage hole gasket at a position between the gasket side passage hole and the heat transfer surface, and a groove dedicated to the passage hole gasket is formed in the groove for exclusive use between the plate cassette and the frame. A gasket for fluid sealing of the side passage hole is attached.

According to the present invention, since the passage hole gasket for fluid sealing the gasket side passage hole between the plate cassette and the frame is mounted in the passage hole gasket exclusive groove having the flat groove bottom without the weld bead, Since it is possible to prevent the occurrence of scratches or cracks on the surface of the hole gasket due to weld beads, even a passage hole gasket with a thickness of about half that of the gaskets interposed between the plate cassettes can be used in the gasket side passage hole between the plate cassette and the frame. The fluid sealability can be stabilized.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The plate heat exchanger of the present invention will be described below with reference to the embodiments shown in FIGS. In the following description, in principle, the same components as those of FIGS. 3 and 4 showing the conventional technique are designated by the same reference numerals, and the description of the overlapping matters will be omitted.

FIG. 1 shows an essential part of a plate cassette (1) used in the welding type plate heat exchanger of the present invention, and FIG. 2 shows the present invention in the portion along the line AA of FIG. FIG. 3 is a cross-sectional view of essential parts of the plate heat exchanger of FIG.

In the plate heat exchanger of the present invention, a welding line (W) is provided at a portion between the gasket side passage hole (4) and the heat transfer surface (2) of the plate (5) forming the plate cassette (1). Groove (9) for the passage hole gasket only by shifting the position
And a passage hole gasket (8) for fluid-sealing the gasket side passage hole (4) between the plate cassette (1) and the frame (7) is mounted in the passage hole gasket dedicated groove (9). .

In the plate heat exchanger of the present invention,
The passage hole gasket (8) for fluid-sealing the gasket side passage hole (4) between the plate cassette (1) and the frame (7) has a flat groove bottom without welding beads, and a passage hole gasket dedicated groove (9) Since it is mounted on the gasket, it is possible to prevent the surface of the passage hole gasket (8) from being scratched or cracked due to the welding bead, and the gasket side passage hole (4) between the plate cassette (1) and the frame (7). It is possible to stabilize the fluid sealing property in (1).

[0017]

As described above, according to the present invention,
By forming a groove dedicated to the passage hole gasket at a position between the gasket side passage hole of the plate forming the plate cassette and the heat transfer surface, the gasket side passage hole between the plate cassette and the frame is formed. The passage hole gasket for fluid sealing can be attached to the passage hole gasket exclusive groove having a flat groove bottom without welding beads.

As a result, the plate type heat exchanger stabilizes the fluid sealability of the passage hole gasket in the gasket side passage hole between the plate cassette and the frame and does not cause scratches or cracks on the surface of the passage hole gasket. The present invention can also be applied to a gasket, such as a resin gasket, which requires smoothness of the surface of the plate.

[Brief description of drawings]

FIG. 1 is a plan view of an essential part of a plate cassette used in a plate heat exchanger of the present invention.

FIG. 2 is a cross-sectional view of an essential part of the plate heat exchanger of the present invention in a portion taken along the line AA in FIG.

FIG. 3 is a plan view of a plate cassette used in a conventional plate heat exchanger.

FIG. 4 is a cross-sectional view of a main part of a conventional plate heat exchanger in a portion along line BB in FIG.

[Explanation of symbols]

 1 plate cassette 2 heat transfer surface 3 welding side passage hole 4 gasket side passage hole 5 plate 6 gasket 7 frame 8 passage hole gasket 9 passage hole gasket dedicated groove W welding line G gasket line

Claims (1)

[Claims] 1. A heat transfer surface and a gasket side passage hole are formed while a welding side passage hole and a gasket side passage hole, which have a heat transfer surface at the center and serve as fluid inlets and outlets, are formed in pairs at four corners. A plate formed with a gasket groove that surrounds the periphery of the substantially trapezoidal region where the
Airtightly welded groove bottoms along a welding line that overlaps as a set of two and connects the welding side passage hole with the heat transfer surface and double blocks the gasket side passage hole from the heat transfer surface. A plate cassette is welded to the plate cassette, and a plurality of plate cassettes are laminated with a gasket interposed between them. Tighten the plate cassettes from both sides with two thick plate frames to alternate the welding side flow passage and the gasket side flow passage. In the plate heat exchanger thus formed, a groove for exclusive use of the passage hole gasket is formed at a position between the gasket side passage hole of the plate forming the plate cassette and the heat transfer surface, and the passage line gasket dedicated groove is formed. A plate-type heat exchanger characterized in that a gasket for fluid-sealing a gasket-side passage hole between a plate cassette and a frame is mounted in a dedicated groove.