WO2012000769A1

WO2012000769A1 - Heat exchanging element for a heat exchanger, method for producing a heat exchanging element for a heat exchanger, heat exchanger, and retrofitting method for a heat exchanger

Info

Publication number: WO2012000769A1
Application number: PCT/EP2011/059649
Authority: WO
Inventors: Marcus Franz; Klaus-Peter Brehler
Original assignee: Sgl Carbon Se
Priority date: 2010-06-30
Filing date: 2011-06-10
Publication date: 2012-01-05
Also published as: BR112012033620A2; DE102010030780A1; CN103038598A; US20130118720A1; EP2588829A1

Abstract

The invention relates to a heat exchanging element (10, 20) for a heat exchanger (100, 200), to a method for producing a heat exchanging element (10, 20) for a heat exchanger (100, 200), to a heat exchanger (100, 200) per se, and to a method for retrofitting an existing heat exchanger, wherein the occurrence of impurities caused by abrasion in one or more heat exchanging media (M1, M2) and/or corrosion is prevented or at least reduced by providing a coating (30).

Description

HEAT TRANSFER ELEMENT FOR A HEAT TRANSMITTER, METHOD FOR CREATING A HEAT TRANSFER ELEMENT FOR A HEAT TRANSFER, THERMAL TRANSMITTER, AND AFTER REFRIGERATION METHOD FOR A HEAT TRANSFER

FIELD OF THE INVENTION

The present invention relates to a heat transfer element for a heat exchanger, a method for producing a heat transfer element for a heat exchanger, a heat exchanger itself, namely using the heat transfer element according to the invention, and a retrofitting method for a heat exchanger. The present invention also relates in particular to CVD-coated and impregnated graphite which is used in particular for a heat transfer element or heat exchanger element, in particular in a core for a block heat exchanger.

INTERGRUN D OF THE INVENTORY

In many areas of chemical and / or physical process engineering, quantities of heat have to be transferred between at least two fluid media, be they liquids, gases, gels, pasty media or the like, in order, for example, to cool or heat an intended process medium. In this case, heat exchangers or heat exchangers are used, which have at least one heat transfer element or heat exchanger element, which in turn is the actual process medium to be heated or cooled and at least one further medium which provides or dissipates the amount of heat and which is often referred to as a service medium is flown, at respective contact surfaces or contact areas, with heat introduced into one of the contact areas or in one of the contact surfaces, via a heat conduction mechanism of the heat transfer element to another contact surface or transferred to another contact area and then released from this to the other medium.

Frequently, heat transfer elements are used which consist essentially of a graphite material which is impregnated with a resin material at the contact surface in contact with a respective medium, e.g. to restrict or even prevent penetration of the respective medium into the porous complex of the material underlying the heat transfer element.

It often happens that when flowing through the respective medium, in particular through the process medium, particles of the resin impregnation and / or the material underlying the heat transfer element, e.g. of the graphite material, physically and / or chemically removed, remain in the actual process medium and thereby contaminate it. Often this can not be done.

Also, corrosion on the material of the heat transfer member and / or peeling off corroded material and contaminating the heat transfer fluid (s) with corroded material of the heat transfer member can often not be tolerated.

SUMMARY OF THE INVENTORY

The invention is based on the object of specifying a heat transfer element for a heat exchanger, a production method for a heat transfer element for a heat exchanger, a heat exchanger itself and a retrofitting method for a heat exchanger, in which a contamination of or in a particularly simple yet reliable manner the heat transfer media by material of the underlying heat transfer element and corrosion of the material or the heat transfer elements and a contamination of the or the heat transfer fluids can be reduced or even prevented with corroded material.

The object underlying the invention is a heat transfer element according to the invention with the features of claim 1, in a method for producing a heat transfer element according to the invention with the features of claim 1 1, in a heat exchanger according to the invention with the features of claim 21 and in a method for retrofitting a heat exchanger according to the invention with the features of claim 22 solved. Advantageous developments are defined in the subclaims.

According to a first aspect of the present invention, a novel heat transfer element for a heat exchanger is provided, which for flow-separated heat transfer between a first heat transfer medium as a process medium and a second heat transfer medium as a service medium, a first contact area and a second contact area for fluidly separated contact with the first heat transfer medium or with the second heat transfer medium formed substantially with or from one or more materials from the group of materials comprising graphite materials, graphites, and open cell and non-sintered SiC or silicon carbide materials, and wherein at least one of the first and second contact regions are partially or completely coated with one or more materials from the group of materials as a coating comprising SiC or silicon carbide rubber erialia, Carbidoxidmaterialien, Silizidmate- materials, tungsten titanate ien and their derivatives and combinations. Here, as the first and second heat transfer media, fluids are possible, e.g. as liquids, gases, gelatinous or pasty media, foams, sludges and their combinations and mixtures.

It is thus a core idea of the present invention, the likelihood of detachment and / or corroding of material, which is at least at one of the first and second contact areas or contact surfaces of the heat transfer element, the heat transfer element underlying material with a particularly resistant or abrasion resistant coating is formed, even if that is the heat transfer element based LIEgende material of a graphite material or an open-pored and / or non-sintered SiC or Siliziumcarbidmaterial is formed.

An impregnation with an impregnating material may be formed with or from one or more materials from the group comprising resin materials, phenolic resin materials and their derivatives, and combinations. The impregnation with the impregnating material serves in particular to avoid too deep penetration and in particular penetration of the material lying on the heat transfer element with one of the heat transfer media whose remaining material is thereby mixed, even if only in the long term, with each other and / or to reduce or prevent contamination in a media change.

The impregnation with the impregnating material may be wholly or partly formed on and / or in the coating and / or completely or partially on and / or in the first contact region and the second contact region. Since the coating to avoid contamination, for example by abrasion or the like, the material underlying the heat transfer element anyway at least partially, if not completely, seals, there closes pores, it is particularly advantageous if an intended impregnation on or in the coating for Avoidance of contamination is or will be formed. This also offers procedural advantages, because in the processing of the coating on the material underlying the heat transfer material does not have to take into account thermal boundary conditions of the material of the impregnation. For example, in the production of high temperature steps be driven without damage or decomposition of the impregnating material is to be expected, since this can then be in retrospect, so after the high-temperature step or introduced.

For the coating with the coating material different structures and methods for their production are conceivable.

The coating may be formed as a CVD coating.

Alternatively or additionally, the coating may be formed as a chemical and / or physical conversion region, in particular via a process of wholly or partially chemical and / or physical conversion of the material of the first and / or second contact region.

The coating may also be alternatively or additionally formed via a process of plasma spraying and / or flame spraying. In addition, the formation of a solid layer on the so-called Flüssigigsil izierung, both in the dipping process as well as in the evaporation process and in the wicking process, has already been successfully tested.

Depending on the nature of the coating material or coating materials, different coating mechanisms and corresponding methods of production may be used, however, forming the coating as a chemical and / or physical conversion layer is particularly elegant, especially if none or in their amount only minor additional material components for coating must be provided.

Various manufacturing methods and structures may or may not be combined in building the coating. The heat transfer element according to the invention can be designed as a heat transfer plate or heat exchanger plate of a plate heat exchanger or plate heat exchanger.

The heat transfer element according to the invention can also be designed as a heat transfer core or block or as a heat exchanger core or block of a block heat exchanger or block heat exchanger.

Furthermore, the heat transfer element according to the invention can be designed as a heat exchanger tube or heat exchanger tube of a tube heat exchanger or tube heat exchanger.

The inventive concept can therefore be used in principle in all heat exchangers or heat exchangers, in which one or more heat transfer elements or heat exchanger elements are used, which follow the above-described principle, namely at least one contact area or at a contact surface of a medium for heat transfer, in particular To be flown to a process med ium and thus come into mechanical contact with this, which due to physical and / or chemical interaction abrasion on a surface of the contact region or the contact surface of the heat transfer element is conceivable.

According to another aspect of the present invention, there is provided a method of manufacturing a heat transfer element for a heat exchanger, wherein the heat transfer element for flow separated heat transfer between a first heat transfer medium as the process medium and a second heat transfer medium as a service medium with a first contact area and with a second contact area to the flow is formed with the first heat transfer medium or with the second heat transfer medium, wherein the heat transfer element substantially with or from one or more materials from the group p is formed of materials comprising graphite materials, graphites, and open-cell and non-sintered SiC or silicon carbide materials, and in which at least one of the first and second contact regions is wholly or partially coated with one or more materials from the group of materials as a coating SiC or Siliziumcarbidmaterial ien, pyrocarbon, oxide ceramics, such as chromium oxides, diamond, Carbidoxidmaterialien, silicide, tungsten titanate materials and their derivatives and combinations.

An impregnation with an impregnating material may be formed with or from one or more of the group consisting of resin materials, phenolic resin materials and their derivatives and combinations.

The impregnation with the impregnating material may be wholly or partly formed on and / or in the coating and / or completely or partially on and / or in the first contact region and the second contact region.

The coating can be formed as a CVD coating.

The coating can also be formed as a CVI coating.

Alternatively or additionally, the coating may be formed as a chemical and / or physical conversion region, in particular via a process of wholly or partly chemical and / or physical conversion of the material of the first and / or second contact region.

The coating may also be additionally or alternatively formed via a process of plasma spraying and / or flame spraying. The heat transfer element may be formed as a heat exchanger plate or heat exchanger plate of a plate heat exchanger or Plattenarnarnnetauschers.

The heat transfer element can also be designed as a heat transfer core or block or as a heat exchanger core or block of a block heat exchanger or block heat exchanger.

Also, the heat transfer element according to the invention can be formed as a heat exchanger tube or heat exchanger tube of a Rohrwärmeübertragers or tube heat exchanger.

According to a further aspect of the present invention, a heat exchanger is provided in which one or more heat transfer elements according to the invention are or are formed.

In addition, according to a further aspect of the present invention, a method for retrofitting an existing heat exchanger is specified, in which one or more existing and in particular conventional heat transfer elements are replaced by one or more corresponding heat transfer elements according to the invention and / or in which one or more existing and In particular, conventional heat transfer elements are converted to heat transfer elements according to the invention, in particular according to the inventive method is used.

These and other aspects will be explained by way of example on the basis of the accompanying schematic drawings.

KU DESCRIPTION OF THE FIGURES

Fig. 1 is a schematic and exploded perspective view of one embodiment of a plate heat exchanger type heat exchanger according to the present invention using FIG an embodiment of the heat transfer element according to the invention in the manner of a heat exchanger plate.

Fig. FIG. 2 shows, in a schematic and perspective side view, a single heat transfer element of the arrangement from FIG. 1 .

Fig. 3A, B show a schematic and sectional side view of two

Intermediate states which are achieved in the embodiment of a production method according to the invention for a heat transfer element according to the invention.

Fig. 4 is a schematic and perspective side view of another embodiment of a heat exchanger according to the invention, in the manner of a block heat exchanger.

Fig. 5A, B show a schematic and sectional side view of two

Intermediate states that are achieved in another embodiment of a manufacturing method according to the invention for a heat transfer element according to the invention.

Fig. 6A, B show a schematic and sectional side view of two

Fig. 7A, B show, in a schematic and sectional plan view, two intermediate states which are achieved in a further embodiment of a production method according to the invention for a heat transfer element according to the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS Hereinafter, embodiments of the present invention will be described. All embodiments of the invention and also their technical features and properties can be individually isolated or optionally assembled together bel iebig and combined without restriction.

Structurally and / or functionally identical, similar or identically acting features or elements are referred to below in connection with the figures with the same reference numerals. Not always will a detailed description of these features or elements be repeated.

First of all, reference is made to the drawings in general.

The present invention relates to a heat transfer element 1 0, 20 for a heat exchanger 1 00, 200, a method for producing a heat transfer element 1 0, 20 for a heat exchanger 1 00, 200, a heat exchanger 1 00, 200 as such and a method for retrofitting a existing heat exchanger, in which by providing a coating 30, the occurrence by abrasion and / or corrosion of generated impurities in one or more heat transfer media M 1, M2 and / or corrosion is prevented or at least reduced or become.

In addition to the general principle described above, the present invention also relates to CVD-coated and impregnated graphite and in particular to its use for the design of heat transfer or heat exchanger elements 10, 20.

Especially in the fine chemicals and pharmaceutical industries, heat exchangers 100, 200 and heat exchangers 100, 200, often made of graphite impregnated with synthetic resin, are used to cool or heat media M1, M2. It happens that graphite particles or particles originating from the impregnation, ie resin particles, through which the heat exchanger 1 00, 200, in particular in the form of a block heat exchanger 200, flowing through Process medium M1 are detached from the surfaces 22v or from the walls 22v of the product bores 22 and / or corroded. These particles are to be regarded as foreign particles because they contaminate the end product, so that in the worst case the entire production batch must be discarded.

To avoid or circumvent this problem, e.g. be thought of using heat exchangers 1 00, 200, the heat transfer elements 1 0, 20 or heat exchanger elements 1 0, 20 are made entirely of silicon carbide or SiC. Compared to graphite heat exchanger elements or heat transfer elements silicon carbide has the advantage that a significantly higher abrasion and / or corrosion resistance is present and thus virtually no silicon carbide particles in the heat transfer medium M 1, M2, in particular in the product medium M 1 or in the product solution M 1 occur.

Disadvantage ig of a completely made of silicon carbide heat transfer element or heat exchanger element are compared to pure graphite many times higher material and manufacturing costs, so that usually can be made of this possibility only in exceptional cases use. In addition, the extremely brittle behavior of SiC ceramics is often disadvantageous due to the application.

The present invention also utilizes the knowledge that, in particular, graphite surfaces can be coated with silicon carbide or SiC by means of a CVD method, which is carried out in particular at temperatures of more than 1000 ° C., in order to reduce the abrasion and / or corrosion resistance of a Heat transfer element 1 0, 20 underlying material 1 0 ', 20', in particular so the underlying graphite material to increase. This also applies to substrates such as CSiC material. Here, the reduced corrosion resistance of free carbon is problematic and contrary to a use of above. It is advantageous that, on the one hand by using eg silicon carbide as coating material 30 ', a higher abrasion resistance is achieved, on the other hand, however, the production costs do not increase excessively, since the underlying material 1 0', 20 'unchanged be an inexpensive material can, in particular a graphite material, which is then refined on its surface by the coating 30 quasi.

In particular, in the case of so-called block heat exchangers 200, it may also be considered to precede the heat exchanger block 20, in particular with respect to the product bores 22, by a block element made entirely of an abrasion-resistant material, e.g. silicon carbide, but which does not include service holes 24 for the second heat transfer medium M2. In this way, it is ensured that the first contact with the process medium M 1 is taken over by an abrasion-resistant component.

Although this makes it possible to lower the extent of contamination, the provision of a bloc which is completely made of abrasion-resistant material is likewise cost-intensive and has the technical disadvantage that a dead volume is introduced before the actual heat exchanger process, thus reducing the overall effectiveness of such a system becomes .

In contrast, the invention proposes a more refined procedure, namely the coating of one or more heat transfer elements 10, 20 of a heat exchanger 100, 200 with an abrasion- and / or corrosion-resistant material 30 ', specifically at least in the areas or partial areas to which a contact done with the process medium M 1.

The invention thus provides a cost-effective and possibly a mechanical, compared to sprouting, more tolerant variant to heat exchanger elements 1 0, 20, for example, to block heat exchangers, which consists entirely of abrasions- and / or corrosion resistant material. It can thus be a cost-effective and hitherto conventional material 10 ', 20' are used for the heat transfer elements 1 0, 20, in which then all surfaces that come into contact with the abrasive and / or corrosive medium M 1, M2, for example, the two End surfaces 20e and the product bores 22 in a block heat exchanger 200, with a layer 30 of an abrasions- and / or corrosion-resistant material 30 ', for example of silicon carbide, are protected and its pores are then completely impregnated with a synthetic resin 40' to the tightness of Heat transfer element 10, 20, in particular to ensure the heat exchanger block 20.

An impregnation 40 or otherwise impregnation 40 based on synthetic resin 40 'is often necessary since it can often not be ensured that each surface of the heat transfer element 10, 20, in particular of the block heat exchanger 200, which comes into contact with the process medium M 1, completely through the used abrasions- and / or corrosion-resistant material 30 ', in particular by the silicon carbide is sealed.

An impregnation 40, in particular with synthetic resin 40 ', must take place after the process of coating with the abrasion- and / or corrosion-resistant material, since temperatures of more than 1000 ° C. during the coating process destroy the material 40' for the impregnation 40 can .

An embodiment of a production method according to the invention for a heat transfer element 10, 20, in particular for a heat exchanger block 200 or the like, may have the following structure:

A finished block 20, for example of graphite 20 'or the like, is coated with a silicon carbide coating 30 based on a CVD method, wherein, for example, the lateral surfaces 20m of the block with a graphite foil can be covered so that there is no coating.

Alternatively, the service bores 24 may be introduced into the block 20 after being coated with the silicon carbide material 30 '.

Subsequently, the silicon carbide 30 'coated block 20 is formed analogous to the preparation of conventional heat exchanger blocks with an impregnation 40, e.g. impregnated with a synthetic resin 40 '. Prior to impregnation 40, the two end faces 20e of the block 20 may be covered with two correspondingly large metal discs, with a seal between each block end face 20e and the metal disc preventing contact of the impregnating resin 40 'with the block end faces 20e and product bores 22. The resin 40 'for impregnation 40 can penetrate into the block 20 via the lateral surfaces 20m and the service bores 24. The jacket disks are e.g. by several tie rods that are passed through the product holes 22, fixed and braced. After the impregnation 40, the block 20 is placed with the strained metal plates in the curing oven. The resin 40 'is cured according to a standard procedure. The end product obtained is a product side coated with silicon carbide and in the product holes 22 resin film-free block 20th

Such and similar production methods according to the invention and heat transfer elements 10, 20 according to the invention have many advantages over known procedures:

The heat exchanger 1 00, 200 or heat exchanger 100, 200, in particular block heat exchanger 200, produced in the manner according to the invention is resistant to abrasive and / or corrosive media and, like a conventional heat exchanger, carries the heat exchange between a process medium M 1 and a service medium M2 completely in, that is without death volumes occur. Furthermore, the abrasion-resistant layer 30 or coating 30, in particular the SiC layer, prevents both the adsorption of media M 1, M2 and their subsequent desorption during a product change or when the service medium M2 is changed. In addition, the abrasion and / or corrosion-resistant layer 30 or the SiC layer 30 can prevent any abrasion or attack of graphite particles or resin particles in the process medium M 1 and thus in the product solution and / or corrosion.

Advantageously, substrate material 10 ', 20' - e.g. the graphite 1 0 ', 20' - and coating material 30 'are matched in terms of their coefficients of thermal expansion.

Namely, according to another aspect of the present invention, the ratio of the thermal expansion coefficients of the substrate material 1 0 ', 20', in particular of the graphite substrate 10 ', 20', and the coating material 30 'and / or impregnating material 40' - in particular the CVD SiC - eg be chosen and adjusted so that these - especially at the highest process temperature - as possible values in the range between about 1, 2 to about 0.8, preferably in the range between about 1, 1 and about 0.9 and more preferably in the range between about 1, 05 to 0.95. Ideally, the thermal expansion coefficients of the material pairings are identical.

Surprisingly, it has been found that layer thicknesses of less than 5 μm are already resistant to abrasion and corrosion. Particles are successfully retained, corrosion of the substrate is prevented, the surface hardness is extremely increased. Ideally, therefore layer thicknesses between 5 and 1000 μιτι applied, preferably between 20 and 400 μιτι and more preferably applied between 50 and 200 μιτι.

Preferred process temperatures are in particular in the range between about 1 .200 ° C and about 2400 ° C, depending on the applied coating process, in particular CVD process. Surprisingly, it is possible to achieve absolutely crack-free coatings by means of such skillfully selected material pairings with respect to their thermal expansion, so that, if necessary, it is entirely possible to do without a seal, for example by means of resins.

Such surfaces produced in addition to a high wear resistance on a high corrosion resistance, which is equivalent in particular to that of a SiC, alpha-SiC or α-SiC.

Now, reference will be made in detail to the drawings.

Fig. 1 shows a schematic and perspective exploded view of an embodiment of a heat exchanger 100 according to the invention in the form of a so-called plate heat exchanger 1 00 'or plate heat exchanger 1 00', which is formed by an arrangement 1 1 0 in the manner of a stack of a plurality of as heat exchanger plates 1 0 or Heat exchanger plates 1 0 formed inventive heat exchanger elements 1 0 or heat exchanger elements 1 0th

The arrows indicate the inflows and outflows of the first and second heat transfer media M 1 and M2, which flow alternately in the spaces R1, Rn as flow spaces, with corresponding sealing devices being provided between the consecutive heat transfer elements 10 (not explicitly shown here), to prevent mixing of the first and second heat transfer media M 1 and M2 together.

Fig. 2 shows a schematic and perspective side view of a single heat transfer element 10 in the form of a heat transfer plate 10 from the arrangement of FIG. 1 . This heat transfer element 10 in plate form essentially consists of a base material 10 ', for example of a graphite material, and has an upper side 10o or front side 10o and a rear side 10u or lower side 10u. The front 1 0o and the back 1 0u may be formed with corresponding flow channels in the surface of the underlying material 10 'of the plate 10 in order to intensify the mechanical contact and thus the heat transfer between the two sides 10o and 10u of the plate 10. These flow or flow channels are not explicitly shown here and form a kind of relief on the top 10o or bottom 1 0u of the plate 10.

The Fig. FIGS. 3A and 3B show different stages of production for the embodiment shown in FIG. 2 illustrated heat transfer element 1 0 in plate form.

In the Fig. 3A is practically the blank for the heat transfer element 1 0 indicated in plate form. This means that the plate 10 essentially consists of e.g. Conventional material 1 0 ', e.g. from a graphite material, as a disk substrate 1 0 'consists. Also indicated are the top 1 0o and the bottom 1 0u of the plate 1 0.

In the transition to the illustration of FIG. 3B, a coating 30 made of an abrasion-resistant material 30 'is then formed at least on the upper side 10o and the lower side 10u.

Often it is sufficient that the side - that is either the top 10o or bottom 1 0u - is formed with the abrasion-resistant material 30 'as a coating 30, which with the actual process med ium, e.g. the heat transfer medium M1, in contact, which must not be contaminated as a product. Whether the service medium, e.g. the second heat transfer medium M2, contaminated or not, is often secondary. Therefore, the page - in Figs. 3A and 3B, the bottom 1 0u - often only optionally form with the coating 30, this is shown in FIG. 3B indicated by dashed lines.

The Fig. 4 shows a schematic and perspective side view of another embodiment of a heat exchanger 200 or heat exchanger 200 according to the invention, namely in the form of a block heat exchanger 200 ' a kreiszyl indrisch trained heat exchanger core or heat exchanger core 20 of a material 20 ', which parallel to the axis of symmetry, ie in the Z direction first, vertical or vertical bores 22 or process bores 22 for the first heat transfer medium M1 or process medium M 1 and perpendicular thereto second or horizontal holes 24 or service bores 24 for the second heat transfer medium M2 o- the service medium M2 has.

The bores 22 and 24 do not communicate with each other, so that mixing of the first and second heat transfer media M 1 and M2 can not take place. For lateral and vertical limitation and for controlling the flows of the first and second heat transfer media M 1 and M2, a guide disk frame 50, 60 with an arrangement of a plurality of guide disks 50, which are clamped in corresponding strips 60, is provided. Shown are still the lateral surface 20m and the end faces 20e of the block formed as heat transfer element 20 and the surfaces 20v, 20h or inner surfaces 20v, 20h of the vertical or horizontal channels or holes 22 and 24th

According to the present invention, in the case of a block-shaped heat transfer element 20 according to FIG. 4 on the one hand, the end surfaces 20e, the lateral surface 20m, but also just the inner surfaces 20v and 20h of the first and second holes 22 and 24 for the process medium M1 and the service medium M2 with a corresponding coating 30 with an abrasion-resistant coating material 30 'be formed ,

This is shown in FIGS. 5A to 7B again in the context of two consecutive process steps in a schematic and sectional side view and in a schematic plan view.

The Fig. 5A and 5B show a section of the arrangement from FIG. 4 for a block-shaped heat transfer element 20, in which case only the vertical bores 22 are shown parallel to the Z direction are, for example, the transport of the process medium M 1 or first heat transfer medium M 1 are used and have inner surfaces 20v.

The base material 20 'of this heat transfer element 20 may be a conventional material 20'. In the transition to the in Fig. 5B, the end surfaces 20e of the block-formed heat transfer element 20 and the inner surfaces 20v or inner sides 20v of the vertical bores 22 or vertical flow channels 22 are then formed with a coating 30 with or from the coating material 30 '. If appropriate, a corresponding coating 30 also results on the end face 20e.

Optionally, the cross section of the vertical bores 22 is slightly restricted, but the illustration in FIGS. 5A to 7B is not to scale; the actual reduction of the clear width of the bores 22 and 24 with the inner surfaces 20v and 20h is only slightly limited.

The same applies to a coating which relates to the lateral surface 20m and the inner surfaces 20h or inner sides 20h of the horizontal bores 24, as shown in FIGS. 6A and 6B analogous to FIGS. 5A and 5B.

The Fig. 7A and 7B show a plan view of the arrangement of the block heat exchanger 200 'of FIG. 4 to 6B against the Z direction, ie directly to the upper end face 20e of the underlying cylinder.

Even with tube heat exchangers, which are not shown graphically here, such a coating 30 on the inside and / or on the outside of a respective heat exchanger tube is conceivable. LIST OF REFERENCE NUMBERS

1 0 Heat transfer element, heat exchanger element, heat transfer plate, heat exchanger plate

1 0 'material of the heat transfer element

1 0o top, front

1 0u bottom, back

20 heat transfer element, heat exchanger element, heat transfer core, heat exchanger core

20 'material of the heat transfer element

20e endface

20h area of horizontal or service hole 24

20m lateral surface

20v surface or inside of the vertical or process bore 22

22 vertical drilling, process drilling, drilling for the first heat transfer or process medium

24 horizontal hole, service hole, hole for the second heat transfer medium or service medium

30 coating

30 'coating material

40 impregnation

40 'impregnating material

50 guide plate for block heat exchanger 200 '

60 bar / frame for diffuser 50 for block heat exchanger 200 '1 00 heat exchanger, heat exchanger,

1 00 'plate heat exchanger, plate heat exchanger

1 1 0 arrangement / stack of a plurality of heat exchanger elements / heat exchanger plates 1 0

200 heat exchangers, heat exchangers

200 'block heat exchanger, block heat exchanger

M1 first heat transfer medium, process medium, product medium M2 second heat transfer medium, service medium Space, flow space, j = 1, n

Claims

1 . Heat transfer element (1 0, 20) for a heat exchanger (1 00, 200),

which for the flow-separated heat transfer between a first heat transfer medium (M1) as a process medium (M 1) and a second heat transfer medium (M2) as a service medium (M2) has a first contact region (10o, 20e, 20v) and a second contact region (10u; 20h, 20m) for flow-separated contact with the first heat transfer medium (M 1) and with the second heat transfer medium (M2),

which is formed substantially with or from one or more materials (10 ', 20') from the group of materials comprising graphite materials, graphites and open-pore and unsintered SiC or silicon carbide materials, and

in which at least one of the first and second contact regions (10o, 20e, 20v, 20u, 20h, 20m) is partially or completely coated with one or more materials from the group of materials (30 ') as coating (30), the SiC or silicon carbide materials, carbide oxide materials, silicide materials, tungsten titanate materials, oxide materials, pyrocarbon, diamond, and their derivatives and combinations.

2. Heat transfer element (1 0, 20) according to claim 1,

wherein an impregnation (40) with an impregnating material (40 ') is formed with or from one or more materials selected from the group consisting of resin materials, phenolic resin material and derivatives thereof, and combinations.

3. heat transfer element (1 0, 20) according to claim 2,

in which the impregnation (40) with the impregnating material (40 ') wholly or partially on and / or in the coating (30) and / or wholly or is partially formed on and / or in the first contact region (1 0o; 20e, 20v) and the second contact region (1 0u; 20h, 20m) is formed.

4. Heat transfer element (1 0, 20) according to one of the preceding claims,

in which the coating (30) is formed as a CVD coating.

5. Heat transfer element (1 0, 20) according to one of the preceding claims,

in which the coating (30) as a chemical and / or physical conversion region - in particular via a process of wholly or partially chemical and / or physical conversion of the material (1 0 ', 20') of the first and / or second contact region (1 0o , 1 0u; 20v, 20h, 20m) - is formed.

6. Heat transfer element (1 0, 20) according to one of the preceding claims,

wherein the coating (30) is formed via a process of plasma spraying and / or flame spraying.

7. Heat transfer element (1 0, 20) according to one of the preceding claims,

which is designed as a heat exchanger plate (1 0) or heat exchanger plate (1 0) of a plate heat exchanger (1 00) or plate heat exchanger (1 00).

8. Heat transfer element (1 0, 20) according to one of the preceding claims 1 to 6,

which is designed as a heat transfer core (20) or heat exchanger core (20) of a block heat exchanger (200) or block heat exchanger (200).

9. heat transfer element (1 0, 20) according to any one of the preceding claims 1 to 6,

which is designed as a heat exchanger tube or heat exchanger tube of a tube heat exchanger or tube heat exchanger.

1 0. Heat transfer element (1 0, 20) according to any one of the preceding claims,

in which the material (10 ', 20') of the heat transfer element (10, 20) and the material (30 ') of the coating (30) are chosen to be coordinated with one another,

in that the ratio of the coefficients of thermal expansion of the material 10 ', 20') of the heat transfer element (10, 20), in particular of a graphite substrate (10 ', 20'), and of the material (30 ') of the coating (30) - in particular one CVD SiC material (30 ') and / or an impregnating material (40') has a value in the range between about 1.2 to about 0.8, preferably in the range between about 1.1 and about 0.9 and more preferably in the range between about 1.05 to about 0.95, in particular in a temperature range of about 1 .200 ° C to about 2400 ° C or a portion thereof.

1 1. Method for producing a heat transfer element (10, 20) for a heat exchanger (100, 200),

in which the heat transfer element (10, 20) for the flow-separated heat transfer between a first heat transfer medium (M 1) as the process medium (M 1) and a second heat transfer medium (M2) as the service medium (M2) with a first contact region (1 0o; 20v) and with a second contact region (1 0u; 20h, 20m) for communicating with the first heat transfer medium (M 1) and the second heat transfer medium (M2) in fluid communication, respectively;

wherein the heat transfer element (10, 20) is formed substantially with or from one or more materials (10 ', 20') from the group of materials comprising graphite materials, graphites, and open cell and non-sintered SiC or silicon carbide materials , and in which at least one of the first and second contact regions (10o, 20e, 20v, 20u, 20h, 20m) is completely or partially coated with one or more materials from the group of materials (30 ') as coating (30), which SiC or silicon carbide materials, carbide oxide materials, silicide materials, tungsten titanate materials and their derivatives and combinations.

1 2. A method according to claim 1 1,

wherein an impregnation (40) with an impregnating material (40 ') is formed with or from one or more materials from the group comprising resin materials, phenolic resin materials and their derivatives, and combinations.

1 3. The method according to any one of the preceding claims 1 1 or 12,

in which the impregnation (40) with the impregnating material (40 ') wholly or partially on and / or in the coating (30) and / or wholly or partly on and / or in the first contact area (1 0o; 20e, 20v) and the second contact region (1 0u; 20h, 20m) is formed.

14. The method according to any one of the preceding claims 1 1 to 1 3,

in which the coating (30) is formed as a CVD coating.

1 5. A method according to any one of the preceding claims 1 1 to 14,

in which the coating (30) as a chemical and / or physical conversion region - in particular via a process of wholly or partially chemical and / or physical conversion of the material (1 0 ', 20') of the first and / or second contact region (1 0o , 10 u; 20v, 20h, 20m) - is formed.

1 6. A method according to any one of the preceding claims 1 1 to 1 5,

1 7. A method according to any one of the preceding claims 1 1 to 1 6, wherein the heat transfer element (10, 20) as a heat exchanger plate (10) or heat exchanger plate (1 0) of a plate heat exchanger (1 00) or plate heat exchanger (1 00) is formed.

1 8. A method according to any one of the preceding claims 1 1 to 1 6,

in which the heat transfer element (1 0, 20) as a heat transfer core (20) or heat exchanger core (20) of a block heat exchanger (200) or block heat exchanger (200) is formed.

1 9. A method according to any one of the preceding claims 1 1 to 1 6,

in which the heat transfer element (10, 20) is designed as a heat exchanger tube or heat exchanger tube of a tube heat exchanger or tube heat exchanger.

20. The method according to any one of the preceding claims 1 1 to 1 9,

in which the material (10 ', 20') of the heat transfer element (10, 20) and the material (30 ') of the coating (30) are or are selected to be coordinated with one another,

21. Heat exchanger (1 00, 200),

in which one or more heat transfer elements (1 0, 20) are formed according to one of claims 1 to 1 0.

22. A method for retrofitting a heat exchanger (1 00, 200), in which one or more existing heat transfer elements by one or more corresponding heat transfer elements (10, 20) are replaced according to one of claims 1 to 1 0 and / or

in which one or more existing heat transfer elements are converted to heat transfer elements (10, 20) according to one of the preceding claims 1 to 10,

in particular according to a method according to one of the preceding claims 1 1 to 20.