JP2000356491A - Plate heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce manufacturing cost significantly by pressing a stainless steel plate to produce a heat transfer plate of specified shape, and plating it with a metallic material suitable for soldering to form a metal film on the entire surface so that welding can be made in an ordinary continuous deoxygenation electric furnace. SOLUTION: A specified number of heat transfer plates 10 for exchanging heat by conducting two kinds of fluid through upper and lower layers separated by one layer sectioned by the upper and lower heat transfer plates 10 by fitting a protruding edge 17 in an upper stage opening 15 are stacked fixedly and welded in an ordinary continuous deoxygenation electric furnace. Since an alloy layer of stainless and metal coating can be formed by welding the metal coating at the part where the upper and lower heat transfer plates 10 touch in the furnace, rigid welding is realized. Furthermore, gastight joint can be realized because the circumferential fringe part is welded at the side edge part 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate heat exchanger formed by laminating a predetermined number of heat transfer plates each having a continuous uneven surface.

[0002]

2. Description of the Related Art In recent years, plate type heat exchangers have been used in heating, cooling and heat recovery processes in various types of chemical equipment and heat appliances. This plate type heat exchanger is composed of multiple layers of heat transfer plates with continuous irregular surfaces such as corrugated or hemispherical shells formed by pressing a metal plate, and a narrow space between the heat transfer plates. A fluid channel at intervals is formed, and two types of fluid such as liquid-liquid and liquid-gas are alternately circulated through this channel to perform heat exchange. High heat efficiency is achieved by a dramatic increase in heat transfer area. Is realized.

[0003]

In order to improve the durability, pressure resistance, chemical resistance, corrosion resistance and other properties of such a plate heat exchanger, a heat transfer plate is formed using a stainless steel plate. However, welding of this stainless steel heat transfer plate
It must be in a high-level deoxygenated atmosphere and must be performed in a furnace with a high vacuum. Therefore, a high-vacuum electric furnace facility capable of controlling the temperature to meet appropriate welding conditions is required, and the number of welds that can be simultaneously processed due to batch processing limited by the furnace volume is limited. However, the welding cost is very high, which has been a major barrier to the spread of the plate heat exchanger made of stainless steel.

An object of the present invention is to solve such a problem, and a heat transfer plate is usually formed by forming a heat transfer plate from stainless steel and plating it with a metal material which can be easily welded. It is an object of the present invention to make it possible to perform welding by a continuous deoxidation electric furnace and to significantly reduce manufacturing costs.

[0005]

In order to achieve the above object, a plate heat exchanger according to the present invention comprises a plate heat exchanger formed by laminating a predetermined number of heat transfer plates each having a continuous uneven surface. In the exchanger, the heat transfer plate is formed into a predetermined shape by pressing a stainless steel plate, and is plated with a metal material suitable for welding to form a metal coating on the entire surface. It is joined by fusion welding.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. In the embodiment shown in the drawings, the heat transfer plate 10 is formed by forming a continuous uneven surface 12 on one surface by pressing a stainless steel plate, and is formed of a metal material (e.g., copper, nickel, or the like) having excellent weldability. The plating process used is performed, and a metal film is formed on the entire surface.

The heat transfer plate 10 is formed in a dish shape in which the planar shape is formed substantially in a square, the uneven surface 12 is formed in a linear corrugated shape, and the side edge portion 11 raised on the peripheral edge is formed. . Two types of openings 15 and 16 are formed at adjacent corners of the heat transfer plate 10, and these openings 15 and 16 are located at radial positions separated from the center of the heat transfer plate 10 by 90 degrees. ing. In addition, one opening 16 is formed with a ridge 17 by burring the periphery thereof, and the other opening 15 is formed to have a size in which the projection 17 is fitted.

The assembly of the plate heat exchanger is performed as shown in FIG. Here, the heat transfer plate 10b superposed on the heat transfer plate 10a is rotated by 90 degrees, and the lower heat transfer plate 1 is inserted into the opening 15b.
The protruding edge 17a of Oa is inserted and overlapped. Similarly, the heat transfer plate 10c is rotated by 90 degrees with respect to the heat transfer plate 10b, the protruding edge 17b is inserted into the opening 15c, and the heat transfer plate 10c is rotated by 90 degrees with respect to the heat transfer plate 10c. Overlap. In this manner, the heat transfer plates 10 are sequentially rotated by 90 degrees, the protruding edges 17 of the lower heat transfer plate 10 are inserted into the openings 15, and a predetermined number of the heat transfer plates 10 are stacked and assembled. FIG. 4 shows a structure in which thirteen heat transfer plates 10 are stacked and formed. Fluid inlet pipes and outlet pipes 20, 21 and 22 are provided in the openings 15 and 16 of the uppermost and lowermost heat transfer plates 10, respectively. , 23 are joined to form a plate heat exchanger.

The flow of the fluid in the plate heat exchanger will be described. Referring to FIG. 3, the fluid flowing into the space between the heat transfer plate 10a and the heat transfer plate 10b from the opening 15a of the heat transfer plate 10a is paired. The heat is distributed in a square shape and guided from the opening 16b of the heat transfer plate 10b to the protruding edge 17b thereof.
d flows into the gap. Thus, the upper and lower heat transfer plates 10
Since the fluid flows through each of the layers partitioned by, and the protruding edge 17 is inserted into the upper hole 15, the respective layers communicate with the upper and lower layers. Therefore, two kinds of fluids, such as liquid-liquid and liquid-gas, are passed through these alternate layers to perform heat exchange. In each layer, the fluid flows in the diagonal direction, and the fluid flowing in the upper and lower layers via the heat transfer plate 10 becomes an intersecting flow, so that efficient heat exchange is performed.

FIG. 5 illustrates the means for welding the plate heat exchanger. As described above, a predetermined number of heat transfer plates 10 are stacked, fixed with a predetermined jig, and welded in a continuous deoxidizing electric furnace. In the furnace, the metal coatings at the portions where the upper and lower heat transfer plates 10 are in contact are fused and welded, and an alloy layer of stainless steel and the metal coatings is formed and welded firmly. Further, the peripheral edge portion is fusion-welded at the side edge portion 11 and is air-tightly joined.
Note that the metal coating is formed with a thickness sufficient for fusion welding.

[0011]

As described above, according to the present invention, the heat transfer plate 10 is formed into a predetermined shape by pressing a stainless steel plate, and the entire surface of the metal plate is plated with a metal material having excellent weldability. By forming the coating, the metal coatings of the stacked heat transfer plates 10 are welded and joined, thereby enabling welding in a normal continuous deoxidizing electric furnace, thereby improving productivity and significantly reducing manufacturing costs. Can be achieved.

Further, uniform and stable welding can be obtained by directly fusing the metal coating, eliminating the difficulty in brazing material placement in welding by the conventional brazing means, saving labor in man-hours for brazing material placement and stabilizing. Welding can be realized.

Further, according to the present invention, since the heat transfer plate 10 is made of stainless steel, the characteristics such as durability, pressure resistance, chemical resistance, and corrosion resistance are improved, and the plate type heat exchanger excellent in these various characteristics is provided. This makes it possible to mass produce containers at low cost.

[Brief description of the drawings]

FIG. 1 is a plan view of a heat transfer plate according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an exploded perspective view showing an assembling method.

FIG. 4 is a sectional view of an assembled state.

FIG. 5 is a sectional view of a main part showing a welding method.

[Explanation of symbols]

 10 Heat transfer plate 12 Uneven surface

Claims (1)

[Claims] 1. A plate type heat exchanger in which a predetermined number of heat transfer plates (10) each having a continuous uneven surface (12) are stacked and formed, wherein the heat transfer plates (10) are formed by pressing a stainless steel plate. A plate type heat exchanger in which a metal coating is formed on the entire surface by forming a predetermined shape with a metal material suitable for welding, forming a metal coating on the entire surface, and joining the metal coatings of the laminated heat transfer plate (10) by welding. .