Patent ID: 12240030

DETAILED DESCRIPTION

FIG.1shows a schematic view of a method known from prior art for manufacturing a plate heat exchanger1.FIG.1shows a frontal view of the components of the plate heat exchanger1, looking at the flow channels A, B.

Accordingly, a plate stack2is formed from a plurality of individual plates3and a plurality of spacers4. Flow channels A, B for two different fluid media are formed alternately between the individual plates.

In this case, two flat individual plates3made for instance of sheet metal are welded together to form a flow channel A, B, with two spacers4interposed therebetween. According to this method, a total of four welding processesare required to form corresponding welds. Consequently, a large number of weldings are required at a large number of welding points marked with black arrows to form the plate stack.

Even though this structure has proven itself in principle, this method is comparatively complex due to the large number of welding processes that are needed, and it requires a comparatively large amount of energy.

The various embodiments of the method according to the disclosure now aim to reduce the number of welding processes required to form a plate stack2in order to simplify the method and reduce the energy requirement in this way.

According to the disclosure, this objective is achieved in all embodiments by a specific use of individual plates in the form of bent metal sheets.

To this end,FIG.2shows a schematic representation of part of the method of the disclosure for manufacturing a plate heat exchanger according to a first embodiment thereof.

A flat metal sheet5is shown in side view. By applying a force6acting in the direction of the surface normal to the edge region8adjacent to a longitudinal edge7of the metal sheet5, the edge region of the metal sheet5is bent by the bending angle α. In this case, the bending process is continued until the bending angle α of 90° is reached. The edge region8extends between the vertical dotted line and the longitudinal edge7.

The result of the bending process is the individual plate9as shown. The individual plate9has a remaining flat surface part10and a seam11, in this case a standing seam.

According to the first embodiment of the disclosure shown inFIG.3, plate pairs12,13are first formed from the individual plates9produced in accordance withFIG.2.

For this purpose, two individual plates9, each in the form of one of the previously bent metal sheets5, are arranged each above other in the stacking direction of the later plate stack14and welded together. With reference to the image plane, the stacking direction of the plate stack14corresponds to the height direction.

The two individual plates9are turned towards each other with their respective seams11, so that a seam11of one individual plate9is assigned to a free marginal edge15of the other individual plate9, the two individual plates9being welded together along their respective seams11and the free marginal edges15cooperating therewith.

It can be seen that due to the design and arrangement of the individual plates9according to the disclosure to form plate pairs12,13, only two weldingsare required per plate pair12,13at the points marked with black arrows to form a flow channel. In prior art as shown inFIG.1, at least four welds are required.

In the next step, as shown inFIG.3, the welded plate pairs12,13are joined together to form a plate stack14, with the interposition of two spacers16,17. In this case, at least two plate pairs12,13arranged on top of each other in the stacking direction of the later plate stack14and welded together. For this purpose, the two plate pairs12,13are arranged one on top of the other, with a first spacer16extending along a first longitudinal edge18and a second spacer17extending along a second longitudinal edge19interposed therebetween. The spacers16,17are then welded to their adjacent plate pairs12,13. In the present case, the longitudinal edges18,19are formed by the respective free marginal edges15.

In the present case, the spacers16,17are formed as rod-shaped profiles with a C-shaped cross-section. The spacers16,17are made of the same material as the metal sheets5. Preferably, the spacers16,17are formed beforehand from a metal sheet5by cutting and bending.

Compared to prior art, significantly fewer weldings are required when using the method according to the disclosure to form three flow channels A-B-A. The method of the disclosure according to the first embodiment only requires eight weldings, whereas a total of 12 (twelve) weldings are required in prior art. This corresponds to an approx. 33% reduction in weldings and the energy required therefor.

FIG.4shows a schematic representation of part of the method in accordance with the disclosure for manufacturing a plate heat exchanger according to a second embodiment.

A flat metal sheet105is shown in a side view. The metal sheet105can be identical to the metal sheet5.

By applying a force106acting in the direction of the surface normal to the edge region108adjacent to a longitudinal edge107of the metal sheet105at one end face, the edge region108of the metal sheet105is bent downwards by the bending angle α relative to the horizontally extending plane of the metal sheet shown inFIG.4. In this case, the bending process is continued until the bending angle α of 90° is reached.

By applying a force106′ acting in the direction of the surface normal to the edge region108′ adjacent to a longitudinal edge107′ of the metal sheet105at the other end face, the edge region108′ of the metal sheet105is bent upwards by the bending angle α′ relative to the horizontally extending plane of the metal sheet shown inFIG.4. In this case, the bending process is continued until the bending angle α′ of 90° is reached. The edge regions108,108′ are therefore bent in the opposite direction relative to the sheet plane.

The result of the bending process is the individual plate109as shown. The individual plate109has a remaining flat surface part110that extends between two seams111,111′, in this case standing seams, extending on both sides. Starting from the flat surface part110, the seams111,111′ extend in the opposite direction from the surface part110, in each case at a right angle away from the latter.

A plate stack114according to the second embodiment shown inFIG.5is formed from the individual plates109produced according toFIG.4.

For this purpose, the individual plates109, each in the form of one of the previously bent metal sheets105, are arranged on top of each other in the stacking direction of the later plate stack114and welded together. With reference to the image plane, the stacking direction of the plate stack114corresponds to the height direction.

Preferably, in this method step, all the individual plates109forming the later plate stack114are arranged on top of each other in a positioning device not shown and then welded together. In this case, at least part of the welding points marked with a black arrow are welded at the same time. Preferably, all welding points in the plate stack114may be welded simultaneously, whereby the process is accelerated in an advantageous manner on the one hand. On the other hand, material stresses in the later plate stack114are avoided by the fact that part of the welding points or all welding points are exposed to the same temperatures at the same time.

The individual plates109are turned towards each other with their respective seams111,111′, so that a seam111of one individual plate109is assigned to a free bending edge120of the other individual plate109and that a seam111′ of one individual plate109is assigned to a free bending edge120′ of the other individual plate109. The individual plates109are then welded together along their respective seams111,111′ and the respective free bending edges120′ cooperating therewith.

It can be seen that due to the design and arrangement of the individual plates109according to the disclosure to form a plate stack114, only two weldingsare required for the connection of two individual plates at the points marked with black arrows to form a flow channel. In prior art according toFIG.1, at least four weldings are required for this.

With regard to the formation of a plate stack in prior art, significantly fewer weldings are required to form three flow channels A-B-A by using the method according to the disclosure. While a total of 12 (twelve) weldings are required for this in prior art, the method of the disclosure according to the second embodiment requires only six weldings. This corresponds to a 50% reduction in weldings and the energy required therefor.

FIG.6shows a third embodiment of the disclosure. Here, a lower part221of the plate stack214in the stacking direction of the plate stack214is first formed in accordance with the first embodiment of the method of the disclosure (FIGS.2and3). Subsequently, the upper part222of the plate stack214in the stacking direction of the plate stack214is formed in accordance with the second embodiment of the method of the disclosure (FIGS.4and5).

For this purpose, a connecting region223is created between the two parts221,222. A plate pair13formed in accordance with the first embodiment is welded, at the welding points marked with black arrows, to an individual plate109formed in accordance with the second embodiment and bent on two sides, with only one spacer16interposed.

In particular, the plate pair13and the single plate109bent on both sides are arranged one on top of the other in the stacking direction of the later plate stack214and welded together. The plate pair13and the individual plate109are arranged one on top of the other with the interposition of a spacer16extending along a first longitudinal edge and a seam111of the individual plate109extending along a second longitudinal edge. The spacer16is then welded to the plate pair13on the one hand and to the free bending edge120′ of the individual plate109on the other hand. Furthermore, the seam111of the individual plate109is welded together with the free bending edge20of the plate pair13.

Subsequently, the upper part222of the plate stack214is formed in accordance with the second embodiment of the method of the disclosure as illustrated inFIGS.4and5.

The lower part221of the plate stack214formed in this way has an increased mechanical strength. In contrast, the upper part222of the plate stack214in the stacking direction has a comparatively low weight. Overall, a particularly mechanically stable plate stack214is formed by this method. In the present case, the flat metal sheets5,105are dimensioned and bent in such a way that the remaining flat surface parts10,110of the individual plates9,109, which are bent on one and on both sides, have identical dimensions.

This embodiment also has a reduced number of required weldingscompared to the method known from prior art.

If the plate stack114,214is formed in accordance with the second or third embodiment of the method of the disclosure, a further method step consists in finalizing the plate stack114,214. In principle, this can be carried out in two different ways, which are shown schematically inFIGS.7and8.

According to a first option illustrated inFIG.7using the example of the plate stack114, the seams111,111′ of the two outermost individual plates109a,109bof the plate stack114extending away from the plate stack114in the stacking direction of the plate stack114are cut to the height of the adjacent free bending edge120,120′. In the present case, this is carried out with the uppermost individual plate109aand the lowermost individual plate109bin the stacking direction to completely finalize the plate stack114at both ends.

This ensures that the individual plates109a,109bdo not have any protruding seams, which reduces the risk of injury to the user and the installation height of the plate stack114. Preferably, the plates can be cut to length in various ways, preferably by means of cutting, milling, sawing and/or grinding.

According to one option illustrated inFIG.8using the example of the plate stack114, two additional individual plates109care first produced according to the example of the method step shown inFIG.2by bending metal sheets along only one edge running in the longitudinal direction. The individual plates109cserve as end plates in the present case.

Subsequently, the plate stack114is closed on both sides by the respective end plate109cwith the uppermost individual plate109ain the stacking direction of the plate stack114and the lowermost individual plate109bbeing turned towards each other with their respective seams111,111′, so that the seam111,111′ of an end plate109cis assigned to a free bending edge120,120′ of the respective individual plate109a,109band so that the seam111,111′ of the respective individual plate109a,109bis assigned to the free marginal edges115of the end plates109c, the end plates109cand the individual plates109a,109bbeing welded together along their respective seams111,111′ and the respective free bending edges120,120′ or free marginal edges115cooperating therewith. This ensures that the plate stack114does not have any protruding seams111,111′, which reduces the risk of injury to the user and the installation height of the plate stack114.

It is also possible to combine the two options shown inFIGS.7and8, for example by cutting the protruding seam111of the lowermost individual plate109bto length in accordance with the first embodiment and welding an end plate109cbent at one side onto the uppermost individual plate109bbent at both sides.

FIGS.9and10show a schematic representation of a further embodiment of the method according to the disclosure for manufacturing a plate heat exchanger according to the first embodiment.

FIG.9shows a flat metal sheet5in a side view. By applying a force6acting in the direction of the surface normal to the edge region8adjacent to a longitudinal edge7of the metal sheet5, the edge region of the metal sheet5is bent by the bending angle α. In this case, the bending process is continued until the bending angle α of 90° is reached.

The intermediate result of the bending process is a metal sheet5which is bent at one end. The metal sheet5has a remaining flat surface part10and a seam11, in this case a standing seam.

To improve the mechanical stability of the resulting plate stack14and to simplify welding, an edge region24of the seam11of the metal sheet5is bent along its free marginal edge25running in the longitudinal direction to create a contact surface26with at least one adjacent individual plate. The edge region24extends between the free marginal edge25and the dashed horizontal line.

In the present case, the seam is bent in the same direction as the first bend in relation to the respective surface normal with a force6′. Furthermore, in the present case, the seam is bent at a bending angle α′ of 90°. The bending angle α′ therefore corresponds to the bending angle α of the first bending. This results in an individual plate9with a flat surface part10and a seam11, the seam having a contact surface26that extends inwards parallel to the remaining flat surface part10.

Plate pairs12,13are first formed in accordance with the first embodiment of the disclosure shown inFIG.10from the individual plates9produced in accordance withFIG.9.

For this purpose, two individual plates9, each in the form of one of the previously bent metal sheets5, are arranged one on top of the other in the stacking direction of the later plate stack14and welded together. With reference to the image plane, the stacking direction of the plate stack14corresponds to the height direction.

The two individual plates9are turned towards each other with their respective contact surfaces26in such a way that a contact surface26of one individual plate9is assigned to a free marginal edge15of the other individual plate9, and the two individual plates9are welded together along their respective contact surfaces26and the free marginal edges15cooperating therewith.

In the next step, as shown inFIG.10, the welded plate pairs12,13are joined together to form a plate stack14with two spacers16,17interposed. In this case, at least two plate pairs12,13are arranged one on top of the other in the stacking direction of the later plate stack14and welded together. For this purpose, the two plate pairs12,13are arranged one on top of the other with the interposition of a first spacer16extending along a first longitudinal edge18and a second spacer17extending along a second longitudinal edge19. The spacers16,17are then welded to the respective adjacent plate pairs12,13. In the present case, the longitudinal edges18,19are formed by the respective free marginal edges15.

In the present case, the spacers16,17are formed as rod-shaped profiles with a C-shaped cross-section. The spacers16,17are formed from the same material as the metal sheets5. Preferably, the spacers16,17are previously formed from a metal sheet5by cutting and bending.

FIGS.11and12show a schematic representation of a further embodiment of the method according to the disclosure for manufacturing a plate heat exchanger according to the first embodiment.

FIG.11shows a flat metal sheet5in a side view. By applying a force6acting in the direction of the surface normal to the edge region8adjacent to a longitudinal edge7of the metal sheet5, the edge region of the metal sheet5is bent by the bending angle α. The bending process continued until the bending angle α of 90° is reached.

The intermediate result of the bending process is a metal sheet5which is bent at one end. The metal sheet5has a remaining flat surface part10and a seam11, in this case a standing seam.

To improve the mechanical stability of the resulting plate stack14and to simplify welding, an edge region24of the seam11of the metal sheet5is bent along its free marginal edge25running in the longitudinal direction to produce a contact surface26with at least one adjacent individual plate. The edge region24extends between the free marginal edge25and the dashed horizontal line.

In the present case, the seam is bent in the opposite direction to the first fold in relation to the respective surface normal. Furthermore, in the present case, bending is performed at a bending angle α′ of 90°. The bending angle α′ thus corresponds to the bending angle α of the first fold. This results in an individual plate9having a flat surface part10and a seam11, the seam having a contact surface26which extends away from the remaining flat surface part10in the same direction.

Plate pairs12,13according to the first embodiment are first formed a shown inFIG.12from the individual plates9according toFIG.11.

For this purpose, two individual plates9, each in the form of one of the previously bent metal sheets, are arranged one on top of the other in the stacking direction of the later plate stack14and welded together. With reference to the image plane, the stacking direction of the plate stack14corresponds to the height direction.

The two individual plates9are turned towards each other with their respective contact surfaces26, so that a contact surface26of one individual plate9is assigned to a free marginal edge15of the other individual plate9, and the two individual plates9are welded together along their respective contact surfaces26and the free marginal edges15cooperating therewith.

In the next step, as shown inFIG.12, the welded plate pairs12,13are joined together to form a plate stack14with two spacers16,17interposed. At least two plate pairs12,13are arranged one on top of the other in the stacking direction of the later plate stack14and welded together. For this purpose, the two plate pairs12,13are arranged one on top of the other with the interposition of a first spacer16extending along a first longitudinal edge18and a second spacer17extending along a second longitudinal edge19. The spacers16,17are then welded to the adjacent plate pairs12,13. In the present case, the longitudinal edges18,19are formed by the respective free marginal edges15.

The spacers16,17are formed as rod-shaped profiles with a C-shaped cross-section. The spacers16,17are formed from the same material as the metal sheets5. Preferably, the spacers16,17are previously formed from a metal sheet5by cutting and bending.

The shape of the individual plates9with the contact area26extending away from the flat surface part10and their special arrangement make welding much easier. This is because the connecting regions between the contact area26and the free marginal edge15for forming the plate pairs on the one hand and between the spacers16,17and the free marginal edge15on the other hand extend away from the plate stack and are therefore more easily accessible for welding tools.

FIGS.13and14show a schematic representation of a further embodiment of the method according to the disclosure for manufacturing a plate heat exchanger according to the first embodiment.

FIG.13shows a flat metal sheet5in a side view. By applying a force in the direction of the surface normal to the edge region8adjacent to a longitudinal edge7of the metal sheet5, the edge region of the metal sheet5is bent by the bending angle α. In the present case, the bending process is continued until the bending angle α of 30° to 50°, preferably 35°, 40°, 45° or 50°, in the present case 45°, is reached.

The intermediate result of the bending process is a metal sheet5which is bent at one end. The metal sheet5has a remaining flat surface part10and a seam11extending at an angle of 135° to the surface part10.

To improve the mechanical stability of the resulting plate stack14and to simplify welding, an edge region24of the seam11of the metal sheet5is bent along its free marginal edge25extending in the longitudinal direction in order to create a contact surface26with at least one adjacent individual plate. The edge region24extends between the free marginal edge25and the dotted line running perpendicular to the seam11.

In the present case, the seam11is bent in the opposite direction to the first seam in relation to the respective surface normal of the edge regions8or25. Furthermore, bending is carried out at an identical bending angle α′ between 30° and 50°, preferably 35°, 40°, 45° or 50°, in this case 45°. The bending angle α′ therefore corresponds to the bending angle α of the first fold. This results in an individual plate9with a flat surface part10and a seam11, the seam having a contact surface26that extends away from the remaining flat surface part10in the same direction.

Plate pairs12,13according to the first embodiment are first formed a shown inFIG.14from the individual plates9according toFIG.13.

For this purpose, two individual plates9, each in the form of one of the previously bent metal sheets, are arranged one on top of the other in the stacking direction of the later plate stack14and welded together. With reference to the image plane, the stacking direction of the plate stack14corresponds to the height direction.

The two individual plates9are turned towards each other with their respective contact surfaces26, so that a contact surface26of one individual plate9is assigned to a free marginal edge15of the other individual plate9and the two individual plates9are welded together along their respective contact surfaces26and the free marginal edges15cooperating therewith.

In the next step, as shown inFIG.14, the welded plate pairs12,13are joined together to form a plate stack14with two spacers16,17interposed. At least two plate pairs12,13are arranged one on top of the other in the stacking direction of the later plate stack14and welded together. For this purpose, the two plate pairs12,13are arranged one on top of the other with the interposition of a first spacer16extending along a first longitudinal edge18and a second spacer17extending along a second longitudinal edge19. The spacers16,17are then welded to the adjacent plate pairs12,13. In the present case, the longitudinal edges18,19are formed by the respective free marginal edges15.

In the present case, the spacers16,17are in the form of rod-shaped profiles with a complex cross-section. A spacer16,17is obtained by a three times bending in the same direction with reference to the respective surface normal. The spacers16,17are formed from the same material as the metal sheets5. Preferably, the spacers16,17are previously formed from a metal sheet5by cutting and bending. The metal sheet is first bent by 90°. The resulting first seam is bent by 45°. The resulting second seam is bent again by 45°. The bending edges of the spacer are spaced apart from each other and their position in the cross-section of the spacer is adapted to the cross-section of the plate pairs12,13that are intended to be directly adjacent in the plate stack. The adaptation is carried out in such a way that the spacers16,17have a contour corresponding to the cross-section of the parts of the respective plate pairs12,13to be welded, at least in sections.

The shape of the individual plates9with the contact area26extending away from the flat surface part10and their special arrangement make welding much easier. This is because the connecting regions between the contact area26and the free marginal edge15for forming the plate pairs on the one hand and between the spacers16,17and the free marginal edge15on the other hand extend away from the plate stack and are therefore more easily accessible for welding tools. In addition, by the selection of the angles α and α′, a comparatively low overall height per flow channel is obtained. As a result, the number of flow channels can be increased for a given plate stack height, which increases the efficiency of the plate heat exchanger.

FIG.15shows a schematic representation of a further embodiment of the method according to the disclosure for manufacturing a plate heat exchanger according to the first embodiment.

Individual plates9produced from metal sheets5in accordance withFIG.11are provided with conical metal elements27. The length of the metal elements27is chosen in the present case in such a way that it essentially corresponds to the distance between two adjacent individual plates9or two adjacent plate pairs12,13. In this way, arching of the respective flat surface part10can be completely prevented. The metal elements27therefore act as spacers.

In the present case, the conical metal elements27are designed in the form of a truncated cone. The metal elements27each have a base surface28at one end and a top surface29at the other end. Circumferentially, the conical metal elements have a circumferential lateral surface30which connects the base surface and the top surface.

The conical metal elements27are each welded with their base surface28onto the flat surface part10of an individual plate9. In the present case, the individual plates9are only fitted with conical metal elements27at one side of the surface part10, but may also be fitted with conical metal elements27at both sides. According to the process control of the first embodiment of the method of the disclosure, if the individual plates are fitted with metal elements at one side and if only identical individual plates are used, this will lead to that the metal elements27are only arranged in flow channels which are formed between individual plates or between plate pairs12,13. In contrast, if identical individual plates9are used, fitting the individual plates with metal elements at both sides makes it possible to realize an arrangement of metal elements27in flow channels which are formed between individual plates9and between plate pairs12,13. Welding the base surface28exclusively to the surface part10is generally sufficient, so that additional weldings of the top surface28can be omitted.

Furthermore, in this embodiment, a relative displacement between the individual plates9and/or the plate pairs12,13as a result of a temperature-induced material movement for instance is possible, so that material stresses are avoided in an advantageous manner.