EP2250457B1 - Plate-type heat exchanger, heat exchanger plate and method for producing the same - Google Patents

Description

The present invention relates to a heat exchanger plate according to the preamble of patent claim 1 for a plate heat exchanger with in the plate plane juxtaposed flow openings for fluid media, which is made of a first material, in particular steel or stainless steel. Such a heat exchanger plate is off GB 20 85 144 A known.

Furthermore, the present invention relates to a plate heat exchanger according to the preamble of claim 8 for fluid media with at least one inlet and at least one outlet for a first, especially less aggressive medium, with at least one inlet and at least one outlet for a second, more aggressive medium and with a A number of heat exchanger plates, which are arranged in fluid communication with the inlets and outlets in the plate heat exchanger.

Finally, the present invention relates to a method for producing a heat exchanger plate according to the invention.

Plate heat exchanger of the type mentioned are, for example, from the EP 0 252 275 A2 known and in the attached FIG. 1 exemplified.

FIG. 1 shows an exploded view of a known heat exchanger in which between end plates 1, 2 a package of substantially rectangular, mutually identical and alternately clamped against each other by 180 ° rotated heat exchanger plates 3 is clamped. In the corner regions of the plates 3 through openings flow openings 4-7 are formed, the result in clamped plate packs, as shown at reference numeral 8, channels 9-12, over the two fluid media for mutual heat exchange alternately formed spaces between the plates 3 be supplied.

The flow openings 4 - 7 may alternatively or additionally also be arranged in other plate areas, in particular the longitudinal sides of the plates.

The existing between the plates 3 spaces for the fluid media are sealed to the outside and alternately to the channels of a medium or the other medium in each case by seals 13, so that in each case one plate gap of the one medium, the following plate gap of the other Medium is flowed through.

The four attached to the end plate 2 outside pipe 14 serve the connection for the supply and discharge of the two media. In addition, the heat exchanger plates 3 are guided between the end plates 1 and 2 by engaging in recesses of the plates 3 rods, of which in FIG. 1 only the lower rod 15 is shown explicitly. Alternatively, the terminals can also be arranged on the other end plate 1.

The above functional description also applies to the present invention.

In the practical application of such plate heat exchangers or heat exchanger plates, it sometimes happens that one of the heat-exchanging media unfolds a particularly aggressive, in particular corrosive, effect with respect to the plate material. In this case, the heat exchanger plates must be made of a more corrosion-resistant material, which resists the aggressive properties of the medium. However, this is associated with considerable additional costs.

The DE 83 10 039 U1 discloses in this context, on at least one side of a heat exchanger plate over the entire surface to apply a higher-quality cover layer. As a result, the aforementioned additional costs are only partially avoided.

The invention has for its object to further develop heat exchanger plates of the type mentioned in that they are also suitable for very aggressive media without the aforementioned cost disadvantages result. At the same time, a method for producing corresponding heat exchanger plates should be specified.

The invention solves the problem with regard to the heat exchanger plate having the features of patent claim 1, with regard to the heat exchanger having the features of claim 8 and with regard to the production method having the features of patent claim 9.

Preferred embodiments of the present invention are the subject of subclaims, the wording of which is hereby incorporated by express reference into the description in order to avoid unnecessary text repetitions.

Furthermore, the present invention provides a method for producing a heat exchanger plate for a plate heat exchanger with in the plate plane juxtaposed flow openings for fluid media, wherein a first raw sheet, the heat exchanger plate in a first material, such as steel, in particular stainless steel is formed, and then the blank sheet his coming into contact with the media surfaces, at least in some areas with a second, in particular higher quality material is occupied. Subsequently, the forming then takes place to the finished heat exchanger plate.

In this way, it is possible according to the invention to specifically influence the created heat exchanger plate in the said subregions by the occupancy of the second material in their resistance, in particular to increase their corrosion resistance to aggressive media, without that to the entire plate would have to be formed in the higher-value, more expensive material.

Preferred developments of the heat exchanger plate according to the invention provide that the second material of higher quality, d. H. in particular corrosion-resistant than the first material, wherein the second material is preferably high-alloy stainless steels, titanium, tantalum or the like. A possible combination of materials for the heat exchanger plate according to the invention thus provides that this is basically made of the usual material, such as steel or stainless steel, and placed on it, at least in some areas with a higher quality material occupied.

Preferably, the second material in the said subregions is applied to the first material by alitizing, anodizing, sherardizing, inchromizing, phosphating, enameling, plating, spraying, hot dipping, galvanically, but in particular by soldering, brazing or welding.

In general, the heat exchanger plate in a large-area, the heat-transferring serving area and the flow-connected terminal portions of the one medium is applied, whereas it is acted upon in two or more adjacent terminal portions, which serve the passage of the other medium from this other medium. At the back of the plate, the conditions are then reversed. The acted upon by different media areas are each separated by seals. Depending on which side of the plate, the aggressive medium flows, the plate is either occupied only in the two relatively small connection areas for the aggressive medium with the more corrosion-resistant material or additionally in the heat exchanging area connected thereto.

The main saving results on that side of the plate, which is acted upon by the less aggressive medium, because there only the relatively small connection areas for the passage of the aggressive medium with the more corrosion-resistant material to be occupied.

It is within the scope of the invention, the plate on the side where it is applied over a large area of the aggressive medium to produce continuously from the higher quality material. But it is particularly advantageous to save the two connection areas for the passage of the less aggressive medium and to occupy with the less expensive, less corrosion-resistant material.

The wall thickness of the higher-grade material occupancy as well as the less high-quality material occupancy should preferably be the same for cost reasons, so that no material offset must be bridged with additional effort to the circumferentially circumferential edge seals the plates.

Most of the different media acted upon areas of the plate are separated by two seals. Then it is recommended that the transitions between adjacent, differently corrosion-resistant material occupancies in the non-flow areas between the two said seals run.

In summary, it can be stated that a heat exchanger plate according to the invention is advantageously only in such sub-areas on its front and / or back with the second, especially higher-grade material is occupied, where this is actually required due to a given media contact, so as to achieve the desired cost advantages ,

Due to the different embodiments of the front and back, it is necessary in a consistent development of the present invention to provide two different types of heat exchanger plates, each of which can be used alternately in the generic plate heat exchanger. This results in a plate design in particular just by mirroring each other on the plate center longitudinal axis.

Figur 1

eine perspektivische Explosionsdarstellung eines bekannten Plattenwärmetauschers;

Figur 2

eine schematische Vorderansicht einer erfindungsgemäßen Wärmetauscherplattefür einen großflächigen Kontakt mit einem aggressivenMedium;

Figur 3

eine schematische Vorderansicht einer erfindungsgemäßen Wärmetauscherplattefür einen großflächigen Kontakt mit einem wenigeraggressiven Medium;

Figur 4

in schematischer Darstellung die Oberseite eines Rohblechs zur Herstellung der erfindungsgemäßen Wärmetauscherplatte in Figur 2;

Figur 4a

eine Schnittansicht entlang der Linie A-A in Figur 4;

Figur 4b

eine Schnittansicht entlang der Linie B-B in Figur 4;

Figur 5

die Rohblechoberseite für die erfindungsgemäße Wärmetauscherplattein Figur 3;

Figur 5a

eine Schnittansicht entlang der Linie C-C in Figur 6a;

Figur 5b

eine Schnittansicht entlang der Linie D-D in Figur 6a; und

Further features and advantages of the present invention will become apparent from the following description of exemplary embodiments and from the drawing. It shows:

FIG. 1

an exploded perspective view of a known plate heat exchanger;

FIG. 2

a schematic front view of a heat exchanger plate according to the invention for a large-area contact with an aggressive medium;

FIG. 3

a schematic front view of a heat exchanger plate according to the invention for a large-area contact with a less aggressive medium;

FIG. 4

in a schematic representation of the top of a blank sheet for producing the heat exchanger plate according to the invention in FIG. 2 ;

FIG. 4a

a sectional view taken along the line AA in FIG. 4 ;

FIG. 4b

a sectional view taken along the line BB in FIG. 4 ;

FIG. 5

the raw sheet top for the heat exchanger plate according to the invention FIG. 3 ;

FIG. 5a

a sectional view taken along the line CC in Figure 6a;

FIG. 5b

a sectional view taken along the line DD in Figure 6a; and

A plate heat exchanger of in FIG. 1 shown and explained above type is known in the art as such. The present invention is particularly concerned with the problem that arises when one of the media supplied to the plate heat exchanger is a relatively aggressive medium capable of attacking the material of the heat exchanger plates 3, in particular by corrosion. In this context, the present invention provides to produce the heat exchanger plates 3 locally of a more corrosion resistant material.

In the figures, the different types of materials are represented by different hatching. In this case, a uniform hatching consisting of solid lines denotes a (relatively) low-grade material, and a hatching of solid and dashed lines denotes a relatively high quality, more corrosion resistant material. In the course of the present invention, the high-grade material is advantageously tantalum (Ta) and the low-grade material is stainless steel, but the present invention would not be limited to such material combinations.

FIG. 2 shows schematically a heat exchanger plate 3a with its designated for an aggressive or corrosive medium front; that is, this side faces a plate gap which is fed with the aggressive medium. For this purpose, it could be according to the invention occupied on its front side over its entire surface with the higher quality material. However, since the plate area effectively acted upon by the aggressive medium is limited by the conventional seal 13a defining the heat exchanging area, the areas of the plate face not coming into contact with the aggressive medium may be made of the conventional base material , These areas could begin immediately at the seal 13a, such as at the lowest point of the seal groove or externally adjacent. However, it is often recommended for reasons of symmetry, only the connection areas around the openings 5 and 7 around, ie to those openings, which are flowed through by the less aggressive medium and surrounded by the usual seals 5a and 7a, from the lower-cost base material or produce it occupy. These areas are marked by reference numerals 16a and 17a. They preferably extend to the middle of the narrow plate side. From there they run in the direction of the seal 13a and then bend into the intermediate region between the seals 5a, 7a and 13a until they reach the plate broadside.

The following on the heat exchanger plate 3a plate 3b is with its front in FIG. 3 shown. It has the same sealing configuration as the back of the plate 3a, that is, the intermediate space formed between the two plates is acted upon by the less aggressive medium supplied through the openings 5 and 7. Here, therefore, the area enclosed by the seal 13 b heat exchanging surface 18 b with the openings 5 and 7 surrounding connection areas 16b and 17b are made of the less expensive, less resistant material, whereas the connection areas 19b and 20b with the seals 4b and 6b surrounded openings 4 and 6 of the more resistant material or must be occupied, because in these openings the more aggressive medium flows.

As can be seen, all connection areas 16a, b; 17a, b; 19a, b; 20a, b the same size and contour, so that the plate gets a symmetrical structure so far.

Behind the plate 3b then again followed by a plate of the type 3a, so that the intervening space behind the plate 3b again flows through the more aggressive medium and so repeats the order of the heat exchanger plates with changing material and sealing configuration in a conventional manner.

Of course, the plates 3a and 3b may be profiled in a known manner by ribs, nubs or the like in order to improve the heat transfer.

The above-described relationships of the plate design according to the invention will be described below with reference to FIGS. 4 and 5 explained in more detail. These show in each case sectional views of unfinished sheet metal parts for the production of the heat exchanger plates 3a, 3b according to the invention according to FIGS. 2 and 3. The term "unfinished sheet" in the context of the present description means that the blank sheets already plated or occupied have not yet been further processed (for example, reshaped or provided with flow openings) to make the ready-to-use heat exchanger plates.

The blank sheet 3a 'according to FIG. 4 is for the preparation of the heat exchanger plate according to FIG. 2 provided and thus has at its illustrated front in right, upper and lower terminal portions 16a and 17a, the lower-grade material, while it is in the main, heat-exchanging region 18a and thus in flow connection areas 19a, 20a left top and bottom made of high quality material.

The FIGS. 4a and 4b show the cross sections AA and BB. You can see in the upper half of FIG. 4a the already designated material transition between highly corrosion-resistant and less corrosion-resistant material, whereas the lower portion of FIG. 4a the conditions at the back of the plate shows where the less high-grade material passes through.

The conditions are different in FIG. 4b , Here runs on the front of the plate of more corrosion-resistant material, whereas at the rear of the higher quality material is required only in the connection area 19b, but not in the adjacent large-area heat exchanging surface 18b.

Analog shows FIG. 5 a blank sheet 3b 'for heat exchanger plates, which are acted upon with their front primarily by the less aggressive medium. The FIGS. 5a and 5b show sectional views along the line CC and the line DD in FIG. 5 ,

Here is the front panel as in FIG. 3 in the large-area heat-exchanging region 18 'and in the two flow-connected connection areas 16b, 17b right above and below from the less corrosion-resistant material, whereas the connection areas 19a, 20b for the more corrosive medium upper left and bottom of the more corrosion resistant material. These connection areas are in fluid communication with the large-area heat exchange area on the plate rear side acted upon by the aggressive medium, so that the latter must be made continuously from the more corrosion-resistant material. You can see this in FIG. 5a where the lower half 18a depicts the back of the plate.

Accordingly one sees in FIG. 5b in that in the cutting region DD the plate front side 16b, 18b is made of the less corrosion-resistant material, whereas the plate back side only has this material in the connection region 16a for the less aggressive medium.

However, it is also within the scope of the invention to design individual connection areas only in one layer. For example, in FIG. 2 and the corresponding one Figures 4 and 4a be dispensed with in the front position on the terminal portions 16a and 17a, so that there only the backsheet 18b is present. The occurring halving in the panel wall thickness can be bridged by a correspondingly stronger seal 5a and 7a. This single-layer design is particularly advantageous in those connection regions which consist of the higher-grade, more corrosion-resistant material. Here could according to FIG. 3 and the corresponding one Figure 5 and 5a waived the connection areas 19b and 20b and the resulting halving of the plate thickness can be compensated by correspondingly thicker seals 4b and 6b.

There are various possibilities for connecting the individual panel layers and layer sections. So it is possible, for example, first a complete plate underside and then produce a complete top plate and then connect these two layers together. Alternatively, however, initially only parts of the top and bottom can be connected to each other and then the still missing connection areas are connected. It is particularly advantageous, however, to assemble the plate from all sections of the top and bottom together with a solder as a binder and then bring about by heating in an oven the connection of all parts simultaneously.

According to the invention heat exchanger plates are provided for a plate heat exchanger in this way, which are able to withstand the action of a relatively aggressive medium, without the entire plate would have to be formed in a high quality and correspondingly more expensive material.

Claims (15)

1. Heat exchanger plate (3a, 3b) for a plate heat exchanger having throughflow openings (4-7) for fluid media arranged in the plane of the plate, which heat exchanger plate is formed in a first material, especially steel or special steel, wherein
   the heat exchanger plate (3a, 3b) is made from another material, or is covered therewith, substantially only in those sub-regions (18a; 19a, b; 20a, b) of the surface of its front and/or rear side(s) in which the heat exchanger plate (3a, 3b) comes into contact with a certain one of the fluid media, especially a relatively more aggressive of the fluid media,
   the heat exchanger plate (3a, 3b) having a heat-exchanging region (18a, 18b) of large surface area on its front side and on its rear side, and
   characterised in that
   the heat exchanger plate (3a, 3b), on its surface (18a, 19a, 20a) that, in the heat-exchanging region (18a), comes into contact with the one of the fluid media, especially a relatively more aggressive of the fluid media, is made from the other material, or is covered therewith, in the heat-exchanging region (18a) and in port regions (19a, 20a) in fluidic communication therewith, and that
   the heat exchanger plate (3a, 3b), on its surface (16b, 17b, 18b) that, in the heat-exchanging region (18b), comes into contact with the other of the fluid media, is made from the other material, or is covered therewith, only in port regions (19b, 20b) for the one medium.
2. Heat exchanger plate (3a, 3b) according to claim 1,
   characterised in that
   the heat exchanger plate (3a, 3b) has on its front side and on its rear side, in addition to the heat-exchanging region (18a, 18b) of large surface area, at least four port regions (16a, b; 17a, b; 19a, b; 20a, b) each containing a throughflow opening (4-7) for the heat-exchanging media, the port regions alternately opening into the heat-exchanging region and being separated therefrom by seals (5a, 7a, 4b, 6b).
3. Heat exchanger plate (3a, 3b) according to claim 1,
   characterised in that
   in the region of holes that form the throughflow openings (4-7), the surface of the heat exchanger plate (3a, 3b) that comes into contact with the one of the fluid media, especially a relatively more aggressive of the fluid media, is made entirely from the other material or is covered therewith.
4. Heat exchanger plate (3a, 3b) according to claim 1,
   characterised in that
   the other material consists of more corrosion-resistant material or is coated therewith.
5. Heat exchanger plate according to claim 4,
   characterised in that
   it is made of the higher grade material, or is covered therewith, both in the port regions (19a, 20a) for the aggressive medium and in the heat-exchanging region (18a) adjoining those port regions.
6. Heat exchanger plate according to claim 1,
   characterised in that,
   in the port regions (16a, 17a) adjacent to the port region(s) (19a, 20a) that are made of the higher grade material, the plate is formed by the lower grade material.
7. Heat exchanger plate according to claim 1,
   characterised in that
   the transitions between neighbouring material coverings of different corrosion resistance run in the regions of the plate that are not acted upon by flow.
8. Plate heat exchanger for fluid media having at least one inlet (9) and at least one outlet (11) for a first medium, especially a less aggressive medium, having at least one inlet (12) and at least one outlet (10) for a second, more aggressive medium and having a number of heat exchanger plates (3) which are arranged in operative fluidic communication with the inlets and outlets in the plate heat exchanger in such a way that the media flow in neighbouring inter-plate spaces,
   characterised in that
   at least some of the heat exchanger plates (3) are in the form of a heat exchanger plate (3a, 3b) in accordance with any one of the preceding claims.
9. Method of producing a heat exchanger plate (3a, 3b) for a plate heat exchanger, wherein the front side of the plate, which is associated with the less corrosive medium, is on its heat-exchanging surface (18b) and in the port regions (16b, 17b) in fluidic communication therewith produced from a less corrosion-resistant material, the port regions (19b, 20b) for the corrosive medium, which are made from a more corrosion-resistant material, being joined thereto, whereas on the rear side of the plate the heat-exchanging surface (18a) and the port regions (19a, 20a) in fluidic communication therewith for the more corrosive medium are produced from a more corrosion-resistant material and the remaining port regions (16a, 17a) from the less corrosion-resistant material and are suitably joined to one another, whereupon the multi-layer plate so formed is subjected to profiling.
10. Method according to claim 9,
    characterised in that
    the layers of a plate with their heat-exchanging regions (18a, 18b) and all port regions (19a, 19b, 20a, 20b) are fully assembled together with a bonding means and are then joined to one another simultaneously, a solder preferably being used as bonding means and the joining preferably taking place in an oven.
11. Method according to claim 9,
    characterised in that
    the different regions of the plate are joined by soldering, especially hard soldering.
12. Method according to claim 9,
    characterised in that
    the resulting multi-layered plate is perforated before and/or after profiling, or sheet metal blanks used to form the multi-layered plate are perforated prior to joining to form the multi-layered plate.
13. Method according to claim 9,
    characterised in that
    asymmetrically shaped continuous layers made of the same one material are produced and those layers are supplemented by port regions made from the other material.
14. Method according to claim 9,
    characterised in that
    only the core regions (18a, 18b) of the sheet metal layers without port regions are produced.
15. Method according to claim 9,
    characterised in that
    the port regions (16a, 17a, 19b, 20b) are of double wall thickness.

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