The present invention relates to a method for executing the attachment of an inlet or outlet sleeve coupling to a supporting plate of a plate heat exchanger.

A plate heat exchanger of this kind is described in more detail in Swedish Patent Application No. 8501599-8, from which this Application is derived.

A plate heat exchanger comprises a number of preferably rectangular plates, of which the outer plates constitute the aforementioned supporting plates. The number of plates is selected having regard for the capacity of the heat exchanger and is joined together during manufacture, for instance by vacuum soldering. One of the supporting plates is provided with cut-outs for inlet and outlet sleeve couplings.

A problem associated with the previously disclosed design is the complex procedure for executing the attachment of the sleeve couplings to the supporting plate.

In accordance with the invention the procedure for executing the attachment of this kind of an inlet or outlet sleeve coupling to a supporting plate of a plate heat exchanger is simplified considerably by the aforementioned sleeve coupling, on the side which it is intended to attach to the supporting plate, first being provided with a section of thinner wall thickness than the rest of the sleeve coupling, by the aforementioned section being introduced into the cut-out intended for the sleeve coupling arranged in the supporting plate, by the outer end of the section being formed around the edge of the cut-out so as to produce a flange, thereby achieving a first fixing of the sleeve coupling, and by the sleeve coupling then being soldered in a previously disclosed fashion in conjunction with the soldering of the assembled heat exchanger.

The invention is described below in further detail with reference to the accompanying drawing, in which Fig. 1 provides a diagrammatic representation of a plate heat exchanger viewed from above without a supporting plate and sleeve couplings. Fig. 2 illustrates in the form of a. cross-section along the line A-A in Fig. 1 a plate heat exchanger with sleeve couplings in accordance with the invention. Fig. 3 illustrates a cross-section along the line B-B in Fig. 1 of the heat exchanger. Fig. 4 illustrates in the form of a detailed view taken from Fig. 3 an attachment of a sleeve coupling in the manner proposed in the invention.

The reference 1 is used in the drawing to designate a plate heat exchanger which comprises a number of plates 2a, 2b, 2c and 2d and inlet and outlet sleeve connections 3, 4, 5, 6. The plates 2a, 2b, 2c and 2d are essentially rectangular and have a relief pattern 7 and a border 8 running around its perimeter. This is off-set in two ledges 9, 10 by approximately one thickness of the plate so that the plates 2a, 2b, 2c and 2d are capable of being inserted into one another. This means that the border 8 can be divided up nto three steps 8a, 8b, 8c. The first step, the so-called pattern step, is so arranged as to enclose the relief pattern 7 of the plate. The second step, which is referred to as the screening step, is intended to integrate the flow area for the flow channel of the subsequent plate. The third step 8c is intended to constitute a joining and sealing element with the second step of the adjacent plate and is accordingly described as the joint step.

The first ledge shall be situated at a distance from the bend in the border 8 which is approximately equal to the depth of the pattern 7 in the plate 2. The second ledge 10 shall be situated at a distance from the bend in the border 8 which is approximately equal to twice the depth of the pattern.

By specifying the position of the two ledges 9, 10 in relation to the depth of the pattern, it is possible to join together plates 2 with different depths of pattern, in so doing enabling the heat exchanger to be given particular characteristics.

In the drawing in accordance with Fig. 3 the inlet and outlet sleeve couplings are designated respectively by 3 and 6 and are attached to the supporting plate 11a by the aforementioned sleeve couplings 3, 6, on the side which it is intended to attach to the supporting plate, being provided with a section 14 of thinner wall thickness than the rest of the sleeve coupling. This section is illustrated in Fig. 4 by a solid line and is shown to be introduced into a cut-out ^' intended for this purpose in the supporting plate. The outer end of the section with thinner wall thickness is then formed around the edge of the cut-out executed in the supporting plate so as to produce a flange 14a. A first fixing between the supporting plate and the sleeve coupling is achieved in this way.

The final fixing is achieved when the assembled heat exchanger 1 is soldered, with this procedure preferably being performed in a vacuum. In order to facilitate the soldering operation, and in order reliably to achieve tight soldered joints, the plates of the heat exchanger, including the supporting plates, are manufactured from a material which consists of, for example, stainless steel sheet with a thin layer of copper applied to it by rolling. The copper layer forms a solder on soldering and also produces a good soldered joint between the supporting plates and the sleeve couplings.