CA2783126C

CA2783126C - Fibre-reinforced ceramic body

Info

Publication number: CA2783126C
Application number: CA2783126A
Authority: CA
Inventors: Marcus Franz
Original assignee: SGL Carbon SE
Current assignee: SGL Carbon SE
Priority date: 2009-12-17
Filing date: 2010-11-10
Publication date: 2015-01-13
Anticipated expiration: 2030-11-10
Also published as: RU2012130063A; KR101426631B1; JP2013514512A; CN102713493A; DE102009054910A1; CA2783126A1; BR112012014847A2; KR20120112552A; WO2011082866A1; US20120267087A1; EP2513589A1

Abstract

The invention relates to a body (1) comprising a ceramic material and which is suitable for use in a heat exchanger and for conducting fluids, characterized in that the outer side (15) of the body (3) is at least partially encompassed by at least two fiber bundles (9) in the longitudinal direction and/or circumferential direction and non-positively connected thereto, wherein the fiber bundles (9) are pre-tensioned and neighboring sections of the fiber bundles (9) are arranged at a predetermined distance. The present invention further relates to a method for producing a body (1) comprising the steps: a) providing a body (3) which comprises a ceramic material and is suitable for use in a heat exchanger and for conducting fluids; and b) encompassing at least sections of the outer side (15) of the body (3) by at least two fiber bundles (9) under a predetermined pre-tension forming a non-positive connection, wherein neighboring sections of the fiber bundle (9) are arranged at a predetermined distance. The invention further relates to the use of the body (1) according to the invention as a pipe or pipe bottom in a heat exchanger.

Description

FIBRE-REINFORCED CERAMIC BODY
The present invention relates to a fibre-reinforced body, a method for the production thereof and the use thereof as a pipe or a pipe bottom in a heat exchanger.
Components made from ceramic material, such as silicon carbide pipes, are often used in heat exchangers. Being of ceramic materials, leak-proof silicon carbide pipes are prone to brittle fracture. In the event of mechanical failure, the pipes fracture catastrophically, i.e. into fractured sections. The pipe loses its integrity. A heat exchanger that has been made from pipes of this kind may be destroyed by a fracture of this nature, as corrosive acids reach the heat exchanger's service compartment, which is not protected against corrosion. In addition, further damage may occur in the cooling system or the heating system to which the heat exchanger is connected.
The problem addressed by the present invention is that of providing a material that is immune to catastrophic brittle fracture.
According to one aspect of the invention, there is provided a body comprising a ceramic material which is suitable for use in a heat exchanger and for conducting fluids, wherein the body is a pipe-shaped body or a cover having a plurality of holes extending in a longitudinal direction thereof, and wherein the ceramic material is dense sintered silicon carbide and the outer side of the body is at least partially encompassed by at least two fibre bundles in either or both of the longitudinal direction and the circumferential direction and is non-positively connected thereto, wherein the fibre bundles are , 25861-94 - la -carbon fibre bundles, wherein the fibre bundles are pre-tensioned and neighbouring sections of the fibre bundles are arranged at a predetermined distance and form a network.
According to another aspect of the invention, there is provided a method for the production of a body comprising the steps a) providing a body which comprises a ceramic material and is suitable for use in a heat exchanger and for conducting fluids, wherein the ceramic material is dense sintered silicon carbide, and b) encompassing at least some sections of the outer side of the body by at least two fibre bundles under a predetermined pre-tension forming a non-positive connection, wherein the fibre bundles are carbon fibre bundles, wherein neighbouring sections of the fibre bundle are arranged at a predetermined distance, wherein the body is a pipe-shaped body or a cover having a plurality of holes extending in a longitudinal direction thereof.
The body according to the invention is a body comprising a ceramic material which is suitable for use in a heat exchanger and for conducting fluids. The outer side of the body is at least partially encompassed by at least two fibre bundles in the longitudinal direction and/or the circumferential direction and non-positively connected thereto. The fibre bundles are pre-tensioned. Neighbouring sections of the fibre bundles are arranged at a predetermined distance. Reinforcing the body by means of the fibre bundles means that it becomes more immune to brittle fracture and its pressure resistance and load-bearing capacity are increased.
The fibre reinforcement improves the properties of bodies as follows: Increase in bursting pressure, the body becomes more immune to brittle fracture, steam hammering and unpermitted exceeding of the operating pressure. Even if fluids are conducted through the fibre-reinforced body during routine operation and a longitudinal crack appears therein, as a result of its age, for example, improper use or overstress, this body does not exhibit any significant leaks up to a predetermined differential pressure. The pushing out or breaking out of fragments of the body is intercepted to a certain extent due to the encompassing of the body with fibre bundles, such that a piece pushing or breaking out of the original form of the body is retained in a predetermined form by the surrounding pre-tensioned fibre bundle. The breaking out of pieces from the body and therefore the emergence of large quantities or fluid are prevented. The heat exchanger in which the body is used can usually be further operated without interruption until there is a planned shutdown. The body according to the invention is therefore leak-proof to a certain extent, even in a defective state, by comparison with the unreinforced body.
The body is preferably a pipe-shaped body. Within the meaning of the present invention, a pipe-shaped body is particularly taken to mean a body which preferably has a circular cross-section and is open at the ends of its longitudinal extension, in order to be suitable for conducting fluids. Alternatively, however, the pipe-shaped body may also exhibit a square, oval or other shaped cross-section. The longitudinal extension of the pipe-shaped body is preferably greater than its cross-section. The pipe-shaped body is preferably a pipe with a circular cross-section.

Alternatively, the body is a cover, wherein a plurality of holes extends in the longitudinal direction of the cover. A
cover in the context of the present invention is taken to mean a body with a preferably circular cross-section, which does not exhibit a single cavity, but a plurality of cavities. In order for it to be suitable for conducting fluids, the cover has a plurality of holes, which extend in the longitudinal direction of the cover and therefore represent cavities. Within the meaning of the present invention, the cover is regarded as a pipe-shaped body, the length dimension of which is not crossed by a single cavity, but by a plurality of cavities, which may lead into a single cavity within the longitudinal g of the cover or may continuously extend separately along the longitudinal direction of the cover. The longitudinal extension of the cover is preferably smaller than its cross-section. It may be so small, for example, that the cover exhibits the shape of a round disc or plate, which is crossed by holes extending in the longitudinal direction. The entire cross-section of the cover may exhibit a plurality of holes.
Alternatively, it is also conceivable that only at least a partial section exhibits a plurality of holes.
In a preferred embodiment, the fibre bundles form a network. This means, for example, that the at least two fibre bundles are inclined towards one another, at + 80 for example, to the longitudinal axis of the body.
The density of the network depends on the nature of the body's application, the load to which the body is exposed and the strength and dimensions of the body. If it is expected that the body will break into smaller fragments in case of a fracture, a dense network of fibre bundles is desirable. On the other hand, the greater use of materials in fibre bundles also raises costs, so that the density of networked fibre bundles used should be individually adapted to the desired effects with regard to the resulting material costs.
In a preferred embodiment, the ratio of the distance between neighbouring fibre bundles/diameter of the fibre bundles is between 5 : 1 and 10 : 1. It is a function of the body's mechanical load. The body's thermal resistance in proportion to the ratio is essentially unchanged. In each direction at an angle to the longitudinal extension of the fibre bundles, comparatively thin fibre bundles and uncovered strips with a broad surface area alternate on the = outer side of the body.
The at least two fibre bundles may encompass or reinforce the body partially or completely. A complete reinforcement is desirable where bodies are subject to heavy loads.
Alternatively, it may also be expedient out of cost considerations for only those parts of the body that are subject to particularly heavy loads to be reinforced. In the case of pipes, for example, end sections, in particular, which are connected to other components, are areas in an apparatus such as a heat exchanger which are subject to a particular load or prone to fractures and may require particular protection in the form of reinforcement.
If the body is a temperature-loaded component, it should furthermore be taken into consideration that the body and fibre bundle may have different thermal expansion coefficients and the length and width of the fibre bundle arrangement should be adapted accordingly. The fibre bundles should therefore be arranged in such a manner on the at least one outer side of the body, that the body's thermal expansion can be compensated by the fibre bundles or can be allowed without leading to the destruction of said body.
The ceramic material is preferably dense sintered silicon carbide. It is chosen for its outstanding properties, such as, for example, high thermal conductivity, high strength, high corrosion resistance to acid and base media and high load-bearing capacity. The silicon carbide is preferably pressureless sintered silicon carbide, which exhibits extremely high corrosion resistance to acid and base media, which it can likewise withstand to very high temperatures, high temperature change resistance, high thermal conductivity, high wear resistance and a hardness resembling that of a diamond. As a further alternative, the silicon carbide may be a liquid phase-sintered silicon carbide, which is produced from silicon carbide and = different oxide ceramics and is characterised by its great strength.
The silicon carbide may contain at least one ceramic or mineral filler material, wherein the choice of filler materials is adapted to the application. Examples or filler materials are materials from the group of naturally occurring flake graphite, artificially produced electrographite, soot or carbon, graphite or carbon fibres or borocarbide. Furthermore, ceramic or mineral filler materials may be used in grain, platelet or fibre form, as silicates, carbonates, sulphates, oxides, glass or selected mixtures thereof.
In a preferred embodiment, the fibre bundles are carbon fibre bundles. A carbon fibre bundle has good tensile strength, corrosion resistance and stiffness, low breaking elongation and is resistant at the application temperatures of loaded bodies. The specific performance of the carbon fibre bundles means that the pre-tensioning of the reinforcement is retained, even if the pipe is subject to highly variable or dynamic loads. Due to the negative thermal longitudinal expansion coefficient of carbon fibre bundles, the reinforcement is further pre-tensioned in case of a temperature rise, the bursting and leak-tight pressure is greater at a higher temperature than at room temperature. The carbon fibre reinforcement improves the properties of bodies, particularly in the case of silicon carbide pipes, as follows: increase in bursting pressure, the body becomes more immune to steam hammering and unpermitted exceeding of the operating pressure, as the body's bursting pressure at room temperature is 30 to 40 %
greater depending on the dimensions compared with the non-reinforced body. Other examples of fibre bundles are glass fibre bundles or aramid fibre bundles.
In a preferred embodiment, the non-positive connection = between fibre bundles and the outer side of the body is an adhesive system. It is used to fix the fibre bundles to the body. The adhesive system is chosen from the group comprising adhesives which are made up of phenolic resin, epoxy resin or polysilazane-based resin. If necessary, the adhesive system may contain a silicon or silicon carbide filler material. It is also referred to as cement in the present invention. The adhesive system may comprise one or more of the adhesives mentioned earlier and/or cement. If necessary, the adhesive or cement may further contain a hardening catalyst and/or a plasticiser. Adhesives or cements of this kind are usually oxidation-resistant. These adhesives or cements also adhere well to both a ceramic material, such as silicon carbide, and also to fibre bundles, such as carbon fibre bundles, and are capable of wetting a fibre effectively.
The adhesive system is preferably a phenol resin. More preferably, the phenol resin is a resol. Alternatively, the phenol resin may also be a novolac. Resin systems containing bisphenol A-diglycidyl ether or bisphenol F-diglycidyl ether are also suitable as epoxy resin. In particular, resin systems which contain methyl hexahydrophthalic acid anhydride, particularly in a quantity of 25 to 50 % by weight, in addition to more than 50 % by weight bisphenol A-diglycidyl ether or bisphenol F-diglycidyl ether, based on the total weight in each case, are suitable as epoxy resin systems. A polysilazane resin system may also preferably be used as the adhesive system.
All the adhesives mentioned above may further contain silicon or silicon carbide as the filler material. The plasticity of the cement may be adjusted to the desired adhesive bond by means of the proportion of resin in the mixture or by adding plasticiser. The use of cement .
containing silicon or silicon carbide alongside the resin adhesive is particularly suitable when it is applied to the . fibre bundle. Through impregnation of the fibre bundle with the cement and subsequent burning, silicon with carbon fibres can form silicon carbide or with silicon carbide as the filler material the impregnated and burnt carbon fibre exhibits silicon carbide.
The choice of adhesive system depends on the desired bond and crucially on the nature of the application of body according to the invention. When selecting an epoxy resin as the adhesive system, which is applied to the body or with which the fibre bundle is impregnated and hardened, a greater reduction in tension is not possible, due for example to the brittleness of the hardened layer, a rigid connection is retained between the fibre bundles and the body. By using plasticisers, this connection can be made deformable, in order to intercept possible shear stresses or different expansions of the fibre bundles and body during temperature changes, for example.
The body and the fibre bundles may be fixed by means of an adhesive system, wherein the adhesive system is either applied to the body, the fibre bundles or both and then hardened or burnt. Alternatively, the body and the fibre bundles may each be provided with an adhesive system independently of one another and fixed to one another. The adhesive systems applied in this case may be identical or different. The choice depends on the adhesive power required and may be appropriately chosen and adapted by the person skilled in the art.
The adhesive system may be arranged at points or in sections between the body and the fibre bundles, so that a number of predetermined points on the fibre bundle are fixed to the body. Alternatively, the fibre bundles may be completely fixed to the body by means of adhesion. The fibre bundles are preferably completely fixed to the body.
.
The fibre bundles may exist in the form of a yarn; this is particularly true when the fibre bundles are wound onto bodies and possibly fixed there. A yarn is taken to be a fibre bundle made up of a plurality of filaments. The yarn may exhibit sections running straight, diagonally and/or in a curved fashion. In order to create a network, at least one, preferably two, yarns intersect at predetermined points at a desired angle, preferably + 80 O. Yarn sections may also be intertwined, meshed or integrated in some other way.
Otherwise, the fibre bundles may also be in the form of braiding, laid webs, knitted fabric, woven fabrics or interlaced yarns, preferably woven fabrics or interlaced yarns, which are pulled onto the body in a pre-tensioned state and fixed where necessary. Braiding is taken to mean an area-measured fabric, which is produced through the intersection of braid/thread systems running diagonally in opposite directions, wherein the braided threads cross one another at an adjustable angle to the fabric edge. A laid web is regarded as an area-measured fabric made up of one or more stretched, superimposed thread systems with different orientation directions, with or without fixing of the points of intersection. A knitted fabric is an area-measured fabric, in which the meshes are formed individually and consecutively from a horizontally laid thread, in addition further thread systems can also be incorporated for reinforcement. An area-measured fabric containing at least two thread systems usually crossing one another at right angles is regarded as a woven fabric. An interlaced yarn is an area-measured fabric, which is produced from one or more threads through the simultaneous formation of meshes in a longitudinal direction; further threads may of course be incorporated for additional reinforcement. At least one fibre bundle of a predetermined length is regarded as the thread in this case. A thread system is taken to mean several threads.
It is of course also possible when the fibre bundles are arranged in the form of a woven fabric or interlaced yarn for the woven fabric or interlaced yarn to be longer than the body, so that where necessary the woven fabric or interlaced yarn protects the connection of the body to a further component through its arrangement on said body.
The body according to the invention can be produced using the following method comprising the steps a) providing a body which comprises a ceramic material and is suitable for use in a heat exchanger and for conducting fluids and b) encompassing at least sections of the outer side of the body by at least two fibre bundles under a predetermined pre-tension forming a non-positive connection, wherein neighbouring sections of the fibre bundle are arranged at a predetermined distance.
With this method, the body's pressure resistance usually required in equipment production is achieved by reinforcing the body with fibre bundles. The pre-tensioning used according to the invention may be adjusted by the person skilled in the art according to the fibre material and area of application of the body.

Step b) may preferably comprise encompassing at least sections of the outer side of the body by at least two fibre bundles, so that the fibre bundles are in the form of a network. Alternatively, it is conceivable for the fibre bundles to be pulled around the body in the form of an area-measured fabric. Step b) is preferably carried out in such a way that the ratio of the distance between neighbouring fibre bundles/diameter of the fibre bundles is between 5 : 1 and 10 : 1. The increase in the strength of the body is thereby achieved with a relatively small covering of the outer side of the body.
In a preferred embodiment, before step b) an adhesive system is at least partially applied to the fibre bundle and/or the body and then hardened or burned. The fibre bundle arrangement is thereby fixed to the outer side of the body. The adhesive system used for fixing is preferably chosen from the group comprising adhesives, which are formed from phenol resin, epoxy resin or polysilazane-based resin and are possibly mixed with silicon and silicon carbide filler material. Adhesive systems of this kind are readily workable and can be adapted to the shape of the body or are well-suited to the impregnation of a fibre, they exhibit good adhesive strength to a ceramic material such as silicon carbide and many types of fibres and, in particular, to a carbon fibre, following thermal hardening or burning.
The body and the fibre bundles may be fixed by means of an adhesive system, wherein the adhesive system is applied either to the body, the fibre bundle or to both and then hardened or burned. An adhesive system which does not contain silicon or silicon carbide as the filler material is hardened, while an adhesive system containing silicon or silicon carbide as the filler material is burnt. Hardening is preferably carried out at temperatures between 120 and 180 C for one to up to two hours, in a pressureless environment or at pressures of between 0.5 and 1.5 bar. At high temperatures, i.e. around 170 to 180 C, a hardening time of up to 15 minutes is generally sufficient. The higher the temperature is, the shorter the hardening time.
If the adhesive system contains a hardening catalyst, the hardening may also take place at room temperature. Burning is preferably carried out at temperatures of over 1500 C
for up to 2 hours, in a pressureless environment or at pressures of 0.5 to 1.5 bar. Following the hardening of the adhesive or burning of the cement, the fibre bundles are arranged on the outer side of the body.
-*
The body and the fibre bundles may be each be provided with an adhesive or cement independently of one another and then fixed. The adhesives or cements applied may be identical or different in this case. The person skilled in the art may select suitable adhesives or cements, which adhere well to one another.
In a preferred embodiment of the method according to the invention, the fibre bundles are impregnated with an adhesive or cement, after which they are hardened or burned and finally arranged on the body.
The adhesive system may be arranged between the body and fibre bundles at points or in sections, so that a number of predetermined points of the fibre bundles are fixed to the body. Alternatively, the fibre bundles may be completely fixed to the body by means of adhesive or cement. The fibre bundles are preferably completely fixed to the body.
The body used in the method according to the invention is preferably a pipe-shaped body or cover, wherein a plurality of holes extends in the longitudinal direction of the cover.
The ceramic material used in the method according to the invention is preferably silicon carbide, which optionally contains at least one ceramic or mineral filler material.
In the method according to the invention, the fibre bundles are preferably carbon fibre bundles. The carbon fibre bundles may be wound around the body in a predetermined pre-tensioned state in the form of a yarn. Alternatively, the carbon fibre bundles exist in the form of braiding, laid webs, knitted fabric, woven fabric or interlaced yarns, preferably woven fabric or interlaced yarns, and are drawn over the at least one outer side of the body possibly provided with a hardened adhesive or burnt cement. On the .-other hand, it is conceivable for the carbon fibre bundle to be used in the method according to the invention as fibre bundles provided with hardened adhesive or burnt cement. Particularly in the case of carbon fibre bundles, the use of cement with silicon as the filler material is suitable, as silicon can react with the carbon fibre during the burning process to produce silicon carbide and a firmer bond between the carbon fibre and the cement can thereby be achieved.
The body according to the invention is particularly suitable for use as a pipe, for example for heat exchangers where there is increased mechanical stress and/or extremely corrosive media and solvents, and also for all other components subject to pressure and temperature loads. It is a particularly ideal material for the construction of heat exchangers, because it is highly thermally conductive, pressure-resistant and immune to brittle fracture. The body according to the invention is particularly preferably used as the pipe in a heat exchanger, because it is erosion-resistant and permits high flow velocities and a self-cleaning effect of the pipe is therefore achievable through fast-flowing media, which may be charged with particles. In addition or alternatively, the body according to the invention is preferably used as a pipe base in a heat exchanger. In assembled form, several pipe-shaped bodies and covers according to the invention are used as a pipe bundle heat exchanger.
A heat exchanger comprising a body according to the invention exhibits the following structure in accordance with DE 197 14 423, for example. The heat exchanger comprises a casing, a base with supports, a spacer to create a distributor space, a distributor base with the inner and outer pipe bases and pipes arranged in the bores of the pipe bases and sealed therein by means of a sealant.
The base and casing are customarily screw-fastened, wherein the spacer is inserted in between to create the distributor space. The inner pipe base of the distributor base is smaller in diameter than the inner casing diameter. The outer pipe base is greater in diameter and therefore assumes the sealing function between the casing and the distributor space. The pipes represent the body according to the invention in the form of a pipe made from pressureless sintered silicon carbide, the outer side of which is encompassed by pre-tensioned carbon fibre bundles.
If there is a temperature increase, the pre-tensioning of the reinforcement is advantageously increased by the negative thermal expansion coefficient of the carbon fibre.
The heat exchanger then works more reliably and safely. In addition or alternatively, the outer and/or inner pipe base may further comprise pressureless sintered silicon carbide, which is encompassed by pre-tensioned carbon fibre bundles.
Alternatively, in addition to the silicon carbide pipe and the network of carbon fibre bundles, the pipes further exhibit one of the adhesive systems described above for fixing the two elements. If the adhesive system is oxidation-resistant, oxidation media may also be used for cooling or heating in the service space of the heat exchanger constructed using this.
Further features and advantages of the invention are now explained with reference to the following figures, without being limited to these.
In the figures:
Figure 1 shows a schematic side view of a body according to the invention;
Figure 2 shows a further schematic side view of the body according to the invention shown in Figure 1, in which a = partial cross-section is shown;
Figure 3 shows an enlarged section from Figure 2, which is circled in Figure 2 using a dot-dash line and marked as and Figure 4 shows a cross-section through a partial area of a further body according to the invention.
A schematic side view of a body 1 according to the invention is shown in Figure 1. Body 1 comprises a smooth-walled pipe 3 made from pressureless sintered silicon carbide. The pipe 3 has an opening at both of its two ends 5, 7, so that it is suitable for conducting fluids. The pipe 3 has yarns 9 made from carbon fibre bundles wound round it, said bundles being highly pre-tensioned and acting as reinforcement for the pipe 3. The yarns 9 exhibit a phenol resin layer (not shown), which acts as an adhesive layer. The yarns 9 are wound around the pipe 3 in such a manner that they cross at predetermined points, so that they form a network.
A further schematic side view of the body 1 according to the invention shown in Figure 1 is depicted in Figure 2. In Figure 2 the same reference numbers are used for the same elements as in Figure 1. In Figure 2 the smooth-walled pipe 3 is likewise shown with the pipe ends 5, 7, said pipe having yarns 9 made from pre-tensioned carbon fibre bundles with a phenol resin layer wound round it. The part of the cross-sectional view further shows a pipe wall 13 of the pipe 3, which exhibits an inner side 14 and an outer side 15. The inner side 14 delimits the hollow cavity 11 of the pipe 3, which is unrestricted in the longitudinal direction and ends in an opening at each of the pipe ends 5, 7. A
fluid may be conducted through the cavity 11 limited by the inner side 14. The yarns 9 are arranged on the outer side 15 of the pipe wall 13.
Figure 3 shows an enlarged section from Figure 2, which is circled in Figure 2 by a dot-dash line and marked as 111-III. In Figure 3 the same reference numbers are used for the same elements as in Figure 2. It can be seen from the enlarged view that the yarns 9 are arranged on the outer side 15 of the pipe wall 13, while the cavity 11 is formed by the inner side 14 of the pipe wall 13.
Figure 4 shows a cross-section through a partial section of a further body 41 according to the invention. The body 41 according to the invention is a smooth-walled pipe 43 made from pressureless sintered silicon carbide. The pipe 43 exhibits a pipe wall 413, which has an inner side 414 and an outer side 415. An adhesive 417 made from phenol resin is disposed on the outer side 415 of the pipe wall 413, on which yarns 49 made from carbon fibres are arranged. The adhesive 417 is only located in those areas of the outer side 415 of the pipe 413 in which the yarns 49 are arranged. The adhesive 417 is used to fix the yarns 49 to the outside 415 of the pipe wall 413. The pipe has a cavity 411, which is limited by the inner side 414 of the pipe wall 413 of the pipe 43.

Claims

1. A body comprising a ceramic material which is suitable for use in a heat exchanger and for conducting fluids, wherein the body is a pipe-shaped body or a cover having a plurality of holes extending in a longitudinal direction thereof, and wherein the ceramic material is dense sintered silicon carbide and the outer side of the body is at least partially encompassed by at least two fibre bundles in either or both of the longitudinal direction and the circumferential direction and is non-positively connected thereto, wherein the fibre bundles are carbon fibre bundles, wherein the fibre bundles are pre-tensioned and neighbouring sections of the fibre bundles are arranged at a predetermined distance and form a network.

2. The body according to Claim 1 wherein the ratio of the distance between neighbouring fibre bundles and a diameter of the fibre bundles is between 5:1 and 10:1.

3. The body according to Claim 1 or 2 wherein the ceramic material contains at least one ceramic or mineral filler material.

4. The body according to any one of the preceding Claims 1 to 3, wherein the non-positive connection between the fibre bundles and the outer side is an adhesive system chosen from the group of adhesives consisting of phenolic resin, epoxy resin and polysilazane-based resin and mixed with silicon and silicon carbide filler material.

5. A method for the production of a body comprising the steps a) providing a body which comprises a ceramic material and is suitable for use in a heat exchanger and for conducting fluids, wherein the ceramic material is dense sintered silicon carbide, and b) encompassing at least some sections of the outer side of the body by at least two fibre'bundles under a predetermined pre-tension forming a non-positive connection, wherein the fibre bundles are carbon fibre bundles, wherein neighbouring sections of the fibre bundle are arranged at a predetermined distance, wherein the body is a pipe-shaped body or a cover having a plurality of holes extending in a longitudinal direction thereof.

6. The method according to Claim 5, wherein step b) comprises encompassing at least some sections of the outer side of the body by the at least two fibre bundles, so that the ratio of the distance between neighbouring fibre bundles and a diameter of the fibre bundles is between 5:1 and 10:1.

7. The method according to any one of the preceding Claims 5 or 6, wherein before step b) an adhesive system is at least partially applied to either or both of the body and the fibre bundles and then hardened or burned.

8. The method according to Claim 7, wherein the adhesive system applied to either or both of the body and the fibre bundles is chosen from the group of adhesives consisting of phenolic resin, epoxy resin and polysilazane-based resin and mixed with silicon and silicon carbide filler material.

9. The method according to any one of the preceding Claims 5 to 8, wherein the ceramic material as employed in step a) contains at least one ceramic or mineral filler material.

10. The use of a body according to any one of the preceding Claims 1 to 4 as the pipe or pipe base in a heat exchanger.