JP2013514512A - Fiber reinforced articles - Google Patents

Abstract

  The invention comprises an article (1) comprising a ceramic material and suitable for use in a heat exchanger and for the passage of fluid, wherein the outer side (15) of the article (3) is at least partly at least two. It is surrounded by the fiber bundle (9) in the longitudinal direction and / or circumferential direction and is connected in a frictional connection with the fiber bundle (9), in which case a pretension is applied to the fiber bundle (9). The article (1) is characterized in that adjacent portions of the fiber bundle (9) are arranged at a predetermined interval. The present invention further comprises the following steps: a) providing an article (3) comprising a ceramic material and suitable for use in a heat exchanger and passage of fluid; and b) of the article (3) At least a portion of the outer side (15) is surrounded by the formation of a frictional connection with at least two fiber bundles (9) under a predetermined pretension, in which case the fiber bundles (9) are adjacent. The present invention relates to a method of manufacturing an article (1), including a step of arranging parts at predetermined intervals. The invention further relates to the use of the article (1) according to the invention as a tube or tube bottom in a heat exchanger.

Description

  The subject of the present invention is a fiber reinforced article, a process for its production and its use as a tube or tube bottom in a heat exchanger.

  In heat exchangers, members from ceramic materials, such as silicon carbide tubes, are often used. A dense silicon carbide tube is easily brittlely fractured as a ceramic material, and when mechanical failure occurs, the tube is catastrophicly broken, that is, broken. The tube loses its concentration. Heat exchangers made from such tubes can be destroyed by this progressive failure, because corrosive acids can enter the unprotected cab of the heat exchanger. To reach. Furthermore, further damage can occur in the cooling or heating system connected to the heat exchanger.

  The object of the present invention is to provide a material having resistance to catastrophic brittle fracture.

  The object is solved by an article having the feature of claim 1 and a method of manufacturing the article having the feature of claim 7.

  The article according to the invention is an article that contains a ceramic material and is suitable for use in a heat exchanger and for the passage of fluids. The outside of the article is at least partially surrounded in the longitudinal and / or circumferential direction by at least two fiber bundles and is frictionally connected to the fiber bundles. The fiber bundle is pretensioned. Adjacent portions of the fiber bundle are arranged at a predetermined interval. By reinforcing the article with the fiber bundle, the article becomes more difficult to brittle fracture, and its pressure resistance and durability are improved.

  This fiber reinforcement improves the properties of the article as follows: increased burst pressure, the article becomes more resistant to brittle fracture, steam impact and unacceptable excess of operating pressure. become. In the course of operation, even if fluid passes through the fiber reinforced article and there are longitudinal cracks in the article, for example due to its age, improper use, or excessive use, in the article There is no leakage to mention up to a certain differential pressure. Protrusion and detachment of the fragments of the article is based on the surrounding of the fiber bundle on the article, and the surrounding fiber bundle in which the fragments protruding or detaching from the original shape of the article are under a pre-tension of a predetermined shape Is inhibited within a predetermined range. Detachment of the debris from the article, and hence a large amount of fluid is prevented from flowing out. The heat exchanger in which the article is used can be further operated until scheduled shutdown, usually without interruption. Thus, the article according to the invention does not leak to a certain extent even in a defective state, in contrast to an article without reinforcement.

  Advantageously, the article is a tubular article. In the sense of the present invention, a tubular article is understood in particular as an article having an advantageously circular cross section and suitable for fluid guidance, with its longitudinally extending ends open. Is done. However, the tubular article may also have a square, oval or other shaped cross section. Advantageously, the longitudinal extension of the tubular article is larger than its cross section. Advantageously, the tubular article is a tube having a circular cross section.

  The article is a cover, and at that time, a number of holes extend in the longitudinal direction of the cover. A cover is understood in the sense of the invention as an article having a number of cavities rather than a single one, preferably having a circular cross section. The cover has a large number of holes so as to be suitable for the passage of fluid, and the holes extend in the longitudinal direction of the cover, which means hollow. In the meaning of the present invention, the cover is regarded as a tubular article, and its length dimension passes through a number of cavities rather than a single hollow, which collects inside the longitudinal extension of the cover. It may be the only hollow, or it may consistently extend separately along the length of the cover. The longitudinal extension of the cover is advantageously smaller than its cross section. The longitudinal extension of the cover may be so small that, for example, the cover has the shape of a circular disc or plate, and a hole extending in the longitudinal direction passes through the disc or plate. . The entire cross section of the cover can have a number of holes. It is also conceivable that only at least one partial area has a large number of holes.

  In one advantageous embodiment, the fiber bundle forms a network. For this purpose, for example, at least two fiber bundles are inclined with respect to the longitudinal axis of the article by, for example, ± 80 °.

  The density of the mesh depends on the manner of use of the article, the load applied to the article, and the strength and dimensions of the article. A dense fiber bundle network is desirable if the article is expected to break into relatively small pieces upon failure. On the other hand, the cost increases as more material is used for the fiber bundles, so the density of the fiber bundles used and reticulated is individually adapted to the desired effect, taking into account the material costs that occur. It is desirable.

  In one advantageous embodiment, the ratio of the spacing between adjacent fiber bundles / diameter of the fiber bundles is 5-10. The ratio correlates with the mechanical load of the article. The thermal resistance of the article as a function of the ratio is substantially unchanged. In each direction inclined with respect to the longitudinal extension of the fiber bundle, there are alternating thin fiber bundles and uncoated strips with a large surface area on the outside of the article. .

  At least two fiber bundles can partially or completely surround or reinforce the article. Full reinforcement is desirable when the article is subjected to high loads. For cost reasons, it is also reasonable to reinforce only a particularly loaded partial range of the article. In the case of pipes, for example, the end range connected to other members in a device such as a heat exchanger is a range that is particularly loaded or prone to breakage, in such a range in the form of reinforcement. Special protection may be required. If the article is a temperature-loaded member, the article and the fiber bundle may further have different coefficients of thermal expansion, and the length and width of the fiber bundle arrangement are adapted accordingly. Should be taken into account. Accordingly, the fiber bundle is arranged outside at least one of the articles such that the thermal expansion of the article can be offset or allowed by the fiber bundle and does not cause its collapse. desirable.

  The ceramic material is preferably densely sintered silicon carbide. The choice is limited by outstanding properties such as high thermal conductivity, high strength, high corrosion resistance and high durability against acidic and basic media. Advantageously, the silicon carbide is silicon carbide sintered without pressure, the silicon carbide being significantly more corrosion resistant to acidic and basic media (which can also withstand very high temperatures), high temperature change endurance , High thermal conductivity, high wear resistance and hardness similar to diamond. Still further, the silicon carbide may be liquid phase sintered silicon carbide, which is produced from silicon carbide and various oxide ceramics, and has high strength.

  The silicon carbide can contain at least one ceramic filler or inorganic filler, in which case the choice of filler can be adapted to the application. Examples for fillers are materials from the group of naturally derived flake graphite, artificially produced electrographite, carbon black or carbon, graphite fiber or carbon fiber or borocarbide. In addition, ceramic fillers or inorganic fillers may be used in granular, platelet or fiber form, for example, silicates, carbonates, sulfates, oxides, glasses, or selected mixtures thereof.

  In one advantageous embodiment, the fiber bundle is a carbon fiber bundle. Carbon fiber bundles have good tensile strength, corrosion resistance and stiffness, slight elongation at break, and are durable at the service temperature of the loaded article. Due to the specific behavior of the carbon fiber bundle, the pretension of the reinforcement is maintained as it is even when the tube load changes or increases in strength. Since the linear thermal expansion coefficient of the carbon fiber bundle is negative, the reinforcement is further pretensioned when the temperature rises, and the burst pressure and the sealing pressure are higher than at room temperature at the elevated temperature. Carbon fiber reinforcement improves the properties of the article, particularly in the case of silicon carbide tubes, as follows: increased burst pressure, the article is more resistant to steam impact and unacceptable excess of operating pressure Because the burst pressure of the article at room temperature is increased by 30-40% depending on the measurement relative to the unstrengthened article. Other examples of fiber bundles are glass fiber bundles or aramid fiber bundles.

  In one advantageous embodiment, the frictional connection between the fiber bundle and the outside of the article is an adhesive system. The adhesive bundle secures the fiber bundle to the article. The adhesive system is selected from the group consisting of adhesives composed of phenolic resins, epoxy resins or polysilazane resin bases. Optionally, the adhesive system may contain a silicon filler and a silicon carbide filler. This is also referred to as a bonding agent in the present invention. The adhesive system can include one or more of the adhesives and / or bonding agents described above. If necessary, the adhesive or the bonding agent can further contain a curing catalyst and / or a plasticizer. Such adhesives or bonding agents are usually oxidation resistant. Further, these adhesives or bonding agents can adhere well to ceramic materials such as silicon carbide and to fiber bundles such as carbon fiber bundles, and to wet the fibers well.

  Advantageously, the adhesive system is a phenolic resin. Advantageously, the phenolic resin is a resole. The phenolic resin may be a novolac. As the epoxy resin, a resin system containing bisphenol A-diglycidyl ether or bisphenol F-diglycidyl ether is suitable. In particular, as an epoxy resin, in addition to more than 50% by weight of bisphenol A-diglycidyl ether or bisphenol F-diglycidyl ether, methylhexahydrophthalic anhydride, Resin systems containing in amounts are preferred. Advantageously, polysilazane resin systems can also be used as adhesive systems.

  All of the above adhesives can further contain silicon or silicon carbide as a filler. The plasticity of the bonding agent can be adapted to the desired adhesive bond strength by the proportion of resin in the mixture or by the addition of a plasticizer. The use of a bonding agent containing silicon or silicon carbide as a filler in addition to the adhesive from the resin is particularly suitable when the bonding agent is applied to a fiber bundle. By impregnating the fiber bundle with a bonding agent and then firing, the silicon can form silicon carbide with the carbon fibers, and the carbon fibers impregnated and fired with silicon carbide as the filler are silicon carbide. Can have.

  The choice of adhesive system depends on the desired bond as well as the type of field of use of the article according to the invention. If an epoxy resin is selected as the adhesive system to be applied to the article or impregnated into the fiber bundle and cured, for example, the cured layer is brittle and a relatively significant reduction in tension is not possible. A firm bond between the fiber bundle and the article is obtained. The plasticity of this bond can be further increased by the addition of a plasticizer, thereby suppressing differences in expansion between the fiber bundle and the article, for example, due to potential shear stress or temperature changes.

  The article and the fiber bundle may be fixed by an adhesive system, wherein the adhesive system is applied to either the article, the fiber bundle or both, and then cured or fired. It is. The article and the fiber bundle may be provided with an adhesive system each time independently of each other and fixed together. The adhesive system applied in each case can be the same or different in this case. This choice depends on the desired adhesion and can be suitably selected and adapted by a person skilled in the art.

  The adhesive system may be arranged in a spot or part between the article and the fiber bundle, so that a predetermined number of locations of the fiber bundle are fixed to the article. The fiber bundle may be completely fixed to the article by adhesion. Advantageously, the fiber bundle is completely fixed to the article.

  The fiber bundle may be in the form of a yarn, especially when the fiber bundle is wrapped around the article and optionally fixed. A yarn is considered to be a bundle of fibers from a number of filaments. The yarn can have a straight, diagonal and / or arcuate portion. In order to form a mesh, at least one, preferably two, yarns intersect at a desired angle at a desired angle, preferably ± 80 °. The yarn portions may be knitted, entangled, or netted in other ways.

  The fiber bundle may also be present as a braid, raid web, weft knitted fabric, woven or warp knitted fabric, preferably woven fabric or warp knitted fabric, which is stretched under pretension on the article, And fixed in some cases. A braid is understood to be a planar structure that results from the intersection of braids / yarn systems that run diagonally in opposite directions, where the braids cross each other at an adjustable angle with respect to the edge of the fabric. ing. A raid web is understood to be a planar structure from one or more stretched and superposed yarn systems of various orientations with no or fixed intersections. A weft knitted fabric is a planar structure in which stitches are formed individually and continuously from yarns provided in a horizontal direction, and other yarn systems may be incorporated for reinforcement. . A woven fabric is a planar structure comprising at least two thread systems that intersect at right angles, usually at right angles. A warp knitted fabric is a planar structure manufactured by simultaneously forming longitudinal stitches from one or more yarns, and, of course, other yarns may be incorporated for reinforcement. . Here, the yarn is regarded as at least one fiber bundle having a predetermined length. A yarn system is understood as a plurality of yarns.

  Of course, when the fiber bundles are arranged in the form of a woven or warp knitted fabric, the woven or warp knitted fabric is longer than the article, so that the woven or warp knitted article is arranged on the article. In some cases, it is possible to protect the connection between the article and another member.

Articles according to the present invention can be manufactured by the following method comprising the following steps:
a) providing an article comprising a ceramic material and suitable for use in a heat exchanger and passing fluid; and b) at least a portion of the outside of the article being at least two under a predetermined pretension. The fiber bundle is surrounded by the formation of a frictional connection, and adjacent portions of the fiber bundle are arranged at a predetermined interval.

  With this method, the pressure resistance of the article generally required in the device structure is achieved by reinforcing the article with fiber bundles. The pretension used according to the invention can be adjusted by the person skilled in the art according to the field of use of the fiber material and the article.

  Advantageously, step b) may comprise surrounding at least a part of the outside of the article with at least two fiber bundles, so that the fiber bundles are in the form of a network. To that end, the fiber bundle may be suitably wrapped around the article. It is also conceivable that the fiber bundle surrounds the article in the form of a planar structure. Advantageously, step b) is carried out such that the ratio of the spacing between adjacent fiber bundles / diameter of the fiber bundles is 5-10. An increase in the strength of the article is thus achieved by a relatively small coating on the outside of the article.

  In one advantageous embodiment, prior to step b), an adhesive system is applied at least partly to the fiber bundle and / or the article and then cured or fired. Thereby, the arrangement of the fiber bundle is fixed to the outside of the article. The adhesive system used for this fixing is advantageously composed of a phenolic resin, an epoxy resin or a polysilazane resin base and an adhesive optionally mixed with a silicon filler and a silicon carbide filler. Is selected from the group consisting of Such adhesive systems have sufficient plasticity and are adaptable to the shape of the article or are suitable for fiber impregnation, and after thermosetting or firing, ceramic materials such as silicon carbide and many Good adhesion to various fiber types, particularly carbon fibers.

  The article and the fiber bundle can be secured by an adhesive system, wherein the adhesive system is applied to the article, one or both of the fiber bundles, and then cured or fired Is done. An adhesive system that does not include silicon or silicon carbide as a filler is cured while an adhesive system that includes silicon or silicon carbide as a filler is fired. Curing is preferably carried out at a temperature of 120 to 180 ° C. within 2 hours, without pressure or at a pressure of 0.5 to 1.5 bar. At high temperatures, i.e. 170-180 [deg.] C., a curing time of up to 15 minutes is generally sufficient. The higher the temperature, the shorter the curing time. If the adhesive system contains a curing catalyst, the curing can occur at room temperature. The calcination is preferably carried out at a temperature above 1500 ° C. within 2 hours without pressure or at a pressure of 0.5 to 1.5 bar. After curing of the adhesive or firing of the bonding agent, the fiber bundle is placed outside the article.

  The article and the fiber bundle can each be applied with an adhesive or a bonding agent independently of each other and then fixed. In this case, the adhesive or bonding agent applied in each case may be the same or different. One skilled in the art can select suitable adhesives or bonding agents that adhere well to each other.

  In a preferred embodiment of the method according to the invention, the fiber bundle is impregnated with an adhesive or bonding agent, then cured or fired and then applied onto the article.

  The adhesive system may be arranged in a spot or part between the article and the fiber bundle, so that a predetermined number of locations of the fiber bundle are fixed to the article. The fiber bundle may be completely fixed to the article with an adhesive or a bonding agent. Advantageously, the fiber bundle is completely fixed to the article.

  Advantageously, the article used in the method according to the invention is a tubular article or a cover, with a number of holes extending in the longitudinal direction of the cover.

  Advantageously, the ceramic material used in the process according to the invention is sintered silicon carbide, which silicon carbide optionally contains at least one ceramic filler or inorganic filler.

  In the process according to the invention, the fiber bundle is preferably a carbon fiber bundle. The carbon fiber bundle may be wound around the article in the form of a yarn under a predetermined pretension. The carbon fiber bundles are also present in the form of braids, raid webs, weft knitted fabrics, woven fabrics or warp knitted fabrics, preferably woven fabrics or warp knitted fabrics, and optionally cured adhesives or fired At least one outer side of the article to which the bonding agent has been applied is surrounded. Furthermore, it is also conceivable to use the carbon fiber bundle as a fiber bundle provided with a cured adhesive or a fired bonding agent in the method according to the invention. In particular, in the case of carbon fiber bundles, it is preferable to use a bonding agent containing silicon as a filler, because silicon and carbon fibers can react to form silicon carbide by a firing process. This is because a firmer bond between the carbon fiber and the bonding agent is thus achieved.

  Articles according to the present invention can be used, for example, as tubes for heat exchangers in elevated mechanical stresses and / or extremely corrosive media and solvents, and as all other pressure- and temperature-loaded components. Is particularly suitable for use. The article is a particularly ideal material for the construction of heat exchangers because it has high thermal conductivity, pressure resistance, and is difficult to brittle fracture. Particularly advantageously, the article according to the invention is used as a tube in a heat exchanger, since the article is resistant to erosion and allows a high flow rate and is therefore optionally loaded with particles. This is because the self-cleaning action of the tube by the medium flowing in the can be realized. Additionally or alternatively, the article according to the invention is advantageously used as the tube bottom in a heat exchanger. A plurality of tubular articles and covers according to the present invention are assembled and used as a tube bundle heat exchanger.

  A heat exchanger comprising an article according to the invention has the following structure, for example according to DE 19714423: the heat exchanger comprises a casing, a bottom with a support, a spacer for providing a distributor space, inner and outer tube bottoms. A distributor bottom provided, and a tube disposed in a hole in the tube bottom and sealed with a sealant therein. The bottom and the casing are usually fastened with bolts, with a spacer inserted between them to provide a distributor chamber. The tube bottom inside the distributor bottom is formed so that the diameter is smaller than the casing inner diameter. The outer tube bottom is formed to have a larger diameter and therefore a sealing action occurs between the casing and the distributor chamber. The tube is an article according to the invention in the form of a tube from silicon carbide sintered without pressure, the outside of which is surrounded by a carbon fiber bundle under pretension. As the temperature rises, the pre-tension of the reinforcement is advantageously increased because the coefficient of thermal expansion of the carbon fiber bundle is negative. The heat exchanger is now more reliable and functions more safely. Additionally or alternatively, the outer and / or inner tube bottoms are made of silicon carbide sintered without pressure, surrounded by a carbon fiber bundle under pretension. Good. In addition to the silicon carbide tube and the net-like carbon fiber bundle for fixing both elements, the tube further has the adhesive system described above. If the adhesive system is oxidation resistant, an oxidizing medium can also be utilized for cooling or heating in the cab of the heat medium constructed therefrom.

  Other features and advantages of the present invention will now be described with reference to the following figures, but are not limited thereto.

FIG. 1 shows a schematic side view of an article according to the invention;
FIG. 2 shows another schematic side view of the article according to the invention shown in FIG. 1, in which a partial cross-section is shown;
FIG. 3 shows a magnified part from FIG. 2, which is surrounded by a broken line in FIG. 2 and indicated by III-III; and FIG. 4 is another partial range of an article according to the invention The cross section of is shown.

Fig. 2 shows a schematic side view of an article according to the invention. Figure 2 shows another schematic side view and partial cross-sectional view of the article according to the invention shown in Figure 1; FIG. 3 shows an enlarged view of a portion from FIG. 2, surrounded by a broken line and indicated by III-III in FIG. 2 shows a cross-section of another partial area of an article according to the invention.

  FIG. 1 shows a schematic side view of an article 1 according to the invention. Article 1 includes a tube 3 with smooth walls from silicon carbide sintered without pressure. At each of its ends 5, 7 the tube 3 has an opening which is suitable for the passage of fluid. The tube 3 is wrapped with yarn 9 from a carbon fiber bundle that is under high pretension and acts as a reinforcement of the tube 3. The yarn 9 has a phenolic resin layer (not shown) which acts as an adhesion layer. The yarns 9 are wound around the tube 3 so as to intersect at a predetermined position and thereby form a mesh.

  FIG. 2 shows another schematic side view of the article 1 according to the invention shown in FIG. 1, in which a partial cross-section is shown. In FIG. 2, the same reference numerals are used for the same elements as in FIG. FIG. 2 shows a tube 3 having a smooth wall portion having tube ends 5 and 7, in which a yarn 9 from a carbon fiber bundle having a phenolic resin layer is under pretension. It is wrapped around The section of the sectional view further shows the tube wall 13 of the tube 3, which has an inner side 14 and an outer side 15. The inner side 14 forms a boundary with the hollow portion 11 of the tube 3, and the hollow portion 11 does not have a boundary in the longitudinal direction and opens at the tube end portions 5 and 7, respectively. The fluid can pass through the hollow portion 11 delimited by the inner side 14. The yarn 9 is arranged on the outer side 15 of the tube wall 13.

  FIG. 3 shows an enlargement of a portion from FIG. 2, surrounded by a broken line in FIG. 2 and indicated by III-III. In FIG. 3, the same reference numerals are used for the same elements as in FIG. From this enlarged view, it can be seen that the yarn 9 is arranged on the outer side 15 of the tube wall 13 while the hollow part 11 is formed by the inner side 14 of the tube wall 13.

  FIG. 4 shows another partial section of an article 41 according to the invention. Article 41 according to the invention is a tube 43 with smooth walls from silicon carbide sintered without pressure. The tube 43 has a tube wall 413, and the tube wall 413 has an inner side 414 and an outer side 415. An adhesive 417 made of phenol resin is disposed on the outer side 415 of the tube wall 413, and a yarn 49 made of carbon fiber is disposed on the adhesive 417. The adhesive 417 exists only in the area of the outer side 415 of the tube 413, and the yarn 49 is disposed in the area. The yarn 49 is fixed to the outer side 415 of the tube wall 413 by the adhesive 417. The tube has a hollow portion 411, and the hollow portion 411 is partitioned by an inner side 414 of the tube wall 413 of the tube 43.

  1 article, 3 article, 5 tube end, 7 tube end, 9 fiber bundle, 11 hollow part, 13 tube wall, 14 inside, 15 outside, 41 article, 43 pipe, 49 fiber bundle, 411 hollow part, 413 pipe Wall, 414 inside, 415 outside, 417 adhesive system

Claims (15)

  In an article (1, 41) comprising a ceramic material and suitable for use in a heat exchanger and passage of fluid, the outside (15, 415) of the article (3, 43) is at least partly at least partially Are surrounded by the two fiber bundles (9, 49) in the longitudinal direction and / or the circumferential direction, and are connected in a frictional connection with the fiber bundles (9, 49). 49) is pre-tensioned, and adjacent parts of the fiber bundle (9, 49) are arranged at a predetermined interval, the article (1, 41).   The article (1, 41) according to claim 1 is a tubular article or a cover, in which a number of holes extend in the longitudinal direction of the cover, in which case a fiber bundle (9 49) The article (1, 41) of claim 1, wherein said article (49) forms a mesh.   The article (1, 41) according to claim 1 or 2, wherein the ratio of the distance between adjacent fiber bundles / diameter of the fiber bundles is 5-10.   The article (1, 41) according to any one of claims 1 to 3, wherein the fiber bundle (9, 49) is a carbon fiber bundle.   The article according to any one of claims 1 to 4, wherein the ceramic material is densely sintered silicon carbide, the silicon carbide optionally containing at least one ceramic filler or inorganic filler. (1, 41).   The frictional connection between the fiber bundle (49) and the outside (415) includes an adhesive system (417), which is from a phenolic resin, epoxy resin or polysilazane resin base. 6. Article (1, 41) according to any one of claims 1 to 5, selected from the group consisting of an adhesive that is configured and optionally mixed with a silicon filler and a silicon carbide filler. . The following steps:
a) providing an article (3, 43) comprising a ceramic material and suitable for use in a heat exchanger and passing fluid; and b) outside (15, 415) of the article (3, 43). At least two fiber bundles (9, 49) under a predetermined pretension in the form of a friction-connective bond, with the fiber bundles (9, 49) being adjacent to each other The manufacturing method of articles | goods (1, 41) including the process of arrange | positioning the part to do at predetermined spacing.   Step b) comprises surrounding at least part of the outside (15, 415) of the article (3, 43) with at least two fiber bundles (9, 49), so that the fiber bundles (9, 49) The method of claim 7, wherein 49) is present in the form of a mesh.   Step b) comprises surrounding at least a portion of the outside (15, 415) of the article (3, 43) with at least two fiber bundles (9, 49), so that the spacing of adjacent fiber bundles / The method according to claim 7 or 8, wherein the ratio of the diameters of the fiber bundles is 5 to 10.   The adhesive system (417) is at least partially applied to the article (43) and / or fiber bundle (49) prior to step b), followed by curing or firing. The method according to claim 1.   The adhesive system (417) is selected from the group consisting of an adhesive composed of a phenolic resin, an epoxy resin or a polysilazane resin base and optionally mixed with a silicon filler and a silicon carbide filler. Item 11. The method according to Item 10.   The article (1, 41) according to any one of claims 7 to 11, wherein the article (1, 41) is a tubular article or a cover, wherein a number of holes extend in the longitudinal direction of the cover. Method.   13. A method according to any one of claims 7 to 12, wherein the fiber bundle (9, 49) is a carbon fiber bundle.   14. A method according to any one of claims 7 to 13, wherein the ceramic material is densely sintered silicon carbide, the silicon carbide optionally containing at least one ceramic filler or inorganic filler. .   Use of the article (1, 41) according to any one of claims 1 to 6 as a tube or tube bottom in a heat exchanger.

Images