CH711385A2 - Method and device for producing a line, line and geothermal probe. - Google Patents

Abstract

The invention relates to a method for producing a line (12), the method comprising weaving a plurality of fibers (16 ', 16 ") into a conductive fabric (18), and conveying the conductive fabric (18) in a feed direction (V ). Further, the method comprises applying a liquid coating material to the inner surface and / or outer surface of the woven power fabric (18), and crosslinking the applied liquid coating material with the conductive fabric (18).

Description

The present invention relates to a method and apparatus for producing a conduit, a conduit and a geothermal probe according to the independent claims.

There are lines or hoses are known, which by weaving or braiding of fibers to a conductive fabric or wire mesh, often referred to as textile lines or textile tubes produced. The fibers used for this purpose include, for example, polyester, aramid or similar, especially tear-resistant materials. In a subsequent process, the wall of the conductive fabric is coated by applying a coating material.

Known methods for applying the liquid coating material on the wall of the conductive fabric have proven to be expensive and heavily tolerant. Thus, it is very common in the art for conventional conduits to have widely varying wall thicknesses, which is undesirable. Also, in the prior art, not always a complete connection of the liquid coating material with the fibers is ensured, so that conventional lines are often leaking and thus water leakage is caused. In particular, when using a line as a geothermal probe, a leak can prove to be very expensive. Another disadvantage in the prior art is that there is no possibility of endless production. In addition, hoses manufactured according to the prior art usually have a high weight and reduced flexibility due to high coating thicknesses.

It is an object of the present invention to provide a method and apparatus for producing a conduit, a conduit and a geothermal probe, in which the disadvantages of the prior art are solved.

According to the invention, the object is achieved by a method for producing a conduit, which comprises: weaving a plurality of fibers into a conductive fabric; Conveying the conductive fabric in a feed direction; Applying a liquid coating material to the inner surface and / or outer surface of the woven power fabric; and bonding the applied liquid coating material to the conductive fabric. Thus, a process with only a few steps for the production of a line with particularly reliable properties is created. In the method according to the invention, immediately after the weaving or braiding process, the liquid coating material is applied directly to the device for this purpose, that is to say a weaving or braiding machine, continuously on the inside and / or outside on the line which is being formed. Thus, the conductive fabric can be directly woven and coated in one operation, the feed of the loom is used at the same time for the stratification of the layer. Thus, an endless production of the line is advantageously made possible. In an unprecedented manner, this has created a considerably shortened process sequence in relation to the prior art. As a result, the extent of the manufacturing device is reduced overall, whereby space and thus costs are saved. Also, the production time is reduced. A further advantage of the method according to the invention is the improved penetration of the liquid coating material into intermediate spaces of the fibers from the conductive fabric. As a result, a high density of the line is achieved. The viscosity of the liquid coating material should be chosen such that unwanted draining or dripping of the material at the vertical portion of the conductive fabric caused, for example, by gravity or any forces or accelerations triggered by the production process, is avoided. Subsequent to the application of the liquid coating material, this reacts or combines with the fibers to form a completely covering, filling layer. This layer can be rubbery and seals particularly reliable. The layer reliably bonds to the fibers and also provides elastic properties. Thus, the line is very robust. The line produced according to the method according to the invention can then be folded, rolled up or folded.

Preferably, the liquid coating material is applied in an annular manner to the moving in the feed direction wire fabric. In this case, the corresponding device for applying the liquid coating material is statically fixed, while the conductive fabric moves along in the feed direction in relation thereto. This relative movement is dependent on the speed of the weaving process. By the word "annular application" it is meant that the liquid coating material is applied to at least one coating site substantially continuously along the inner surface and / or outer surface of the conductive fabric.

Preferably, the bonding of the applied liquid coating material with the conductive fabric comprises flowing around the fibers with the liquid coating material and then curing the same.

Preferably, the coating material comprises silicone, polyurethane or polyurea. These materials are particularly reliable for sealing, which permanently prevents leakage of the pipe. The coating material may also comprise other materials which contribute to the elastic sealing.

Preferably, the layer thickness of the applied liquid coating material is adjusted at least one point downstream of the application via a knife coating or calendering. In the case of knife coating, the liquid coating material is applied in front of a doctor blade or upstream of it. The doctor blade coating is particularly preferred over known methods with regard to the setting of thin layer thicknesses. By shearing under the doctor blade, the liquid coating material is homogeneously distributed and simultaneously penetrates into the conductive fabric, whereby a good bond is achieved. By appropriate choice of the distance between the doctor blade and the conductive fabric, the resulting thickness of the coating can be reliably defined as a whole. For very low application weights on the doctor blade, the doctor blade is pressed directly onto the fibers of the conductive fabric during the coating process (air knife). As a result, very thin application thicknesses of up to 10 μm can be achieved. As mentioned above, particularly thin layers can be achieved by the method according to the invention, wherein the use of a highly elastic coating material with a high elongation at break nevertheless nevertheless advantageously achieves a robust and sealing coating of the conductive fabric.

Preferably, the method further comprises penetrating the conduit tissue with the liquid coating material by applying a negative pressure to the conduit tissue at a location thereof that at least partially opposes the conduit tissue at the location for applying the liquid coating agent. The wording "oppression" refers to a negative pressure in relation to the atmospheric pressure. Due to the applied negative pressure, the liquid coating material stored on the opposite side of the conductive fabric is sucked into the conductive fabric. Thus, the liquid coating material is advantageously uniformly distributed between any interstices of the conductive fabric and bonds to each fiber. The resulting line will therefore have a particularly reliable density, and the coating is particularly robust by the connection of the overlying defined layer with the retracted into the tissue coating material. It may be provided an annular chamber in which the negative pressure is set to the atmospheric pressure, said annular chamber enclosing the conductive fabric substantially sealingly. Further, this annular chamber is disposed at a position opposite to the registration of the liquid coating material. The applied negative pressure is, for example, metered or adjusted to the viscosity of the liquid coating material such that the set negative pressure pulls the material through the mesh or interstices of the fabric or braid of the conduit until, for example, the side opposite the registration of the material of the conductive fabric (inner surface or outer surface) closes so opaque that all stitches or fibers are covered.

Preferably, the method further comprises tempering the fibers upstream of the coating and / or the coated conductive fabric downstream of the coating. By tempering the fibers prior to coating, i. cooled or heated, the retraction of the liquid coating material is supported in the tissue or the mesh of the conductive fabric. As a result, the coating quality can be further improved. By controlling the temperature of the coated conductive fabric at a location downstream of the coating, the bond between the liquid coating material and the fibers is further promoted. Depending on the particular chemical composition of the liquid coating material, this compound can be obtained by adding or removing heat (infrared or hot air), by irradiation with UV light or solely by the chemical reaction with a mixing of two components (in the case of a two-component coating , eg Polyurea).

Preferably, the method further comprises passing a separate inner conduit within the conduit tissue along its advancement direction. As a result, in contrast to currently known methods, a coaxial "double line" can be created, as used, for example, for a geothermal probe. The inner pipe has a smaller diameter in relation to the manufactured pipe and may be loosely inserted into the pipe or connected to the pipe of larger diameter. The wording "loose" means that the inner pipe comes to rest over the entire length of the double pipe to be produced without adhering to the coating material and, if necessary, can also be removed again. In an alternative example, instead of the inner line, only a rope, a string, a band, a cable, a line of some kind or the like can be inserted. The sealing coating of the produced outer line is independent of the inner line. An advantage of the embodiment described is that the inner conduit (or cord described above) can be embedded directly during the manufacture of the conduit. This avoids having to introduce the inner pipe at a later time, which is particularly important in the case of very long pipes, e.g. occur in geothermal probes, which are also often rolled up due to their length, is very tedious and time consuming. In order to avoid that the inner pipe comes into contact with sections thereof during the production process of the pipe to be produced, the inner pipe can be insulated from the outside environment by a cylindrical separating element. In this way it can be ensured that the inner pipe can be passed through separately without it coming into contact with the liquid coating material. Thus, the coating is not destroyed. The cylindrical separator may also ensure that the inner conduit is protected against prevailing process conditions, e.g., applied thermal radiation, UV radiation, etc. Thus, the inner pipe is passed through during the coating process protected by the manufacturing device. Alternatively or additionally, by applying suitable means, for example a powder, the inner pipe can be protected from sticking to the inner surface of the pipe to be produced or adhering to it, which would cause damage.

The above object is also achieved by a device for producing a line. This apparatus comprises weaving means for weaving a plurality of fibers into a conductive fabric; a conveyor for conveying the conductive fabric in a feed direction; an application device for applying a liquid coating material to at least the inner surface and / or outer surface of the conductive fabric; and a crosslinking device for crosslinking the applied liquid coating material, for example by means of heat or UV light. This device allows application of the liquid coating material at or in the immediate vicinity of the station where the conductive fabric is woven. Thus, these two process stations are hardly spaced apart, whereby advantageously the extent of the device can be reduced overall. In addition, the manufacturing device allows a particularly reliable connection between the liquid coating material and the individual fibers of the conductive fabric. This results in a manufactured line, which is particularly well sealed and thus will not cause leakage in later use.

Preferably, the device further comprises a vacuum device for applying a negative pressure to the conductive fabric at a position thereof, which at least partially opposite to the line fabric of the point for applying the liquid coating material. Thus, the liquid coating material is continuously passed through or pulled through all stitches of the fabric until it closes opaque on the opposite side of the entry, so that all mesh or fibers are covered. This results in a line that meets the highest tightness requirements.

Preferably, the coating material comprises silicone, polyurethane or polyurea. These materials are particularly reliable for sealing, which permanently prevents leakage of the pipe. There are other materials possible, which contribute to the elastic sealing.

The invention also relates to a conduit which is made by a method according to any one of claims 1 to 8. Furthermore, the invention relates to a geothermal probe with a line according to claim 12 for use in geothermal energy.

It is expressly understood that the above embodiments are arbitrarily combinable. Only those combinations of variants are excluded, which would lead to contradictions by the combination.

In the following, the present invention will be explained with reference to embodiments illustrated in the drawings. Showing: <Tb> FIG. 1: <SEP> is a schematic representation of a device for producing a line; <Tb> FIG. Fig. 2: <SEP> is a schematic detail view of the manufacturing apparatus in Fig. 1; and <Tb> FIG. FIG. 3: shows a further schematic detail view of the production device in FIG. 1. FIG.

Fig. 1 shows a schematic representation of an apparatus 10 for producing a line 12. Within a schematically illustrated weaving device 14 of the device 10 respectively supplied fibers 16, 16 are woven into a conductive fabric 18. The fibers can be unwound over a plurality of fiber drums 20, 20. As the weaving method, a known warp weft weaving method is used. In this case, a plurality of fiber webs (warp threads) are guided annularly to the point of use and the crowd of approximately parallel fibers is woven by means of at least one perpendicular to this (shot) weft yarn fiber.

On the resulting fabric, hereinafter referred to as conductive fabric 18, a coating material is then applied to the outside and / or inside, which is a liquid coating material. In this case, the liquid coating material combines with the fibers of the conductive fabric 18 and subsequently hardens, wherein the coating material can be selected such that it nevertheless remains elastic and flexible after curing. Thus, a conduit 12 is made with a water-impermeable wall, which can pass lossless water or other liquids. An exemplary application of such a conduit is to use it as a conduit from a geothermal probe. The conductive fabric 18 is advanced in a feed direction indicated by an arrow V. The feed rate depends on the weaving speed within the weaving device 14.

In the section of the weaving device 14, the manufacturing device 10 likewise comprises a coating head or a coating device 22, which is shown only schematically in FIG. 1. Within the coating device 22, a liquid coating material is applied to the conducted in the feed direction V conductive fabric 18 such that the conductive fabric 18 is hereby completely penetrated. The liquid coating material is supplied from a coating material storage means 24. Details of the coating are explained in more detail below. Simultaneously with the weaving and coating of the woven conductive fabric 18, an inner pipe 26 is passed substantially centrally through the weaving device 14 and the coating device 22. The inner pipe 26 is continuously supplied from an inner pipe supply device 28, for example a roller. The finished line 12 is led out of the device 10 at the feed rate and can then be rolled up, for example, onto a roll (not shown). Thus, an endless production is advantageously possible.

Although in the example shown in Fig. 1, the coating device 22 is displayed as disposed within the conductive fabric 18 (inner surface), the coating device 22 may also be arranged outside the conductive fabric 18 (outer surface). In other words, the coating can be performed from the inside to the outside or from the outside to the inside, while known methods usually work from the outside inwards.

Fig. 2 shows an enlarged view of the coating device 22 shown in Fig. 1 in a schematic view for explaining the basic principle. The previously woven conductive fabric 18 passes through the coating device 22 in the feed direction V, i. in the view shown in Fig. 2 from top to bottom. In this direction V, the conductive fabric 18 passes over a coating material applicator 30, which stores liquid coating material 32. In this case, the coating material 32 penetrates into the conductive fabric 18 guided past, thereby penetrating any meshes or interspaces of the braid. In order to achieve a uniform and continuous coating, the coating material applicator element 30 is arranged annularly around the inner surface of the conductive fabric 18.

The penetration of the coating material 32 into the conductive fabric 18 is further promoted by providing a vacuum chamber 34 on the opposite side (outer surface) of the conductive fabric 18 and at a corresponding location to the coating material applicator element 30. The vacuum chamber 34 is in direct contact with the outer surface of the conductive fabric 18 and is hereby substantially sealed. The vacuum chamber 34 applies (in relation to the atmospheric pressure) a negative pressure to the outer surface of the conductive fabric 18, whereby the liquid coating material 32 is further reliably pulled through the conductive fabric 18. Thus, the conductive fabric 18 is completely penetrated to the outer surface with the liquid coating material 32. The vacuum chamber 34 is, for example, annularly arranged around the outer surface of the conductive fabric 18 around. Although not shown, the coating can be applied using the same application principle in several stages or layers. In this case, it is possible first to apply a layer which promotes adhesion to the fabric or braid and then a further layer of the actual sealing material. For this purpose, an additional coating device (not shown) may be provided accordingly.

The downstream of the coating material applicator element 30 continuously advanced coated wire mesh 36 then passes through a crosslinking device 38, which performs the networking. The crosslinking occurs (depending on the chemical composition of the coating material) e.g. by the supply or removal of heat (infrared or hot air) or by the irradiation with UV light. In the example shown in FIG. 2, the cross-linking device 38 comprises four infrared radiators 40 - 40, which irradiate the outer surface and inner surface of the coated conductive fabric 36 with infrared rays. A plurality of infrared radiators may be arranged concentrically with respect to both the inner surface and the outer surface of the coated conductive fabric 36, thus ensuring the most uniform possible irradiation with infrared rays. The liquid coating material 32 is continuously supplied from the coating material storage device (see FIG. 1) through a supply line 42.

Simultaneously with the aforementioned process steps, the inner pipe 26 is passed through the coating head 22. Here, the inner pipe 26 is guided in the example shown in Fig. 2 by a cylindrical partition member 44, so as to prevent the inner pipe 26 with the conductive fabric 18 and in particular the coated conductive fabric 36 comes into contact. The cylindrical separator 44 also protects the internal duct 26 guided therein against adverse effects by the cross-linking device 38. In other words, the internal conduit 26 is replaced by the cylindrical separator 44, e.g. against increased heat input, against UV rays and / or other effects by the crosslinking device 38, which could affect the inner line 26 or even destroy protected. Although, in the example shown in FIG. 2, the coating material applicator 30 is shown as being located within the conduit fabric 18 (inner surface) and the vacuum chamber 34 is located outside the conduit fabric 18 (outer surface), this arrangement may also be reversed. Although not shown in the figures, it is also possible to operate with an overpressure (relative to ambient pressure) and thus to force the coating material through the tissue. For this purpose, the coating head is structurally adjusted accordingly, so that the overpressure can not escape. The coating of the tubular fabric 18 can in principle be applied "endlessly" by the coating device 22 allowing a switch between two separately replaceable tanks (not shown) for storing the liquid coating material 32.

Known methods usually work with thermoplastics as coating materials, which must be processed under very high pressure (> 100bar) and correspondingly high temperatures in extruders. On the other hand, the process according to the invention can be based decisively on the processing of silicone and PL1 or PUA formulations or similar materials which are liquid at room temperature, do not have to be extruded due to their low viscosity and are formulated chemically in such a way that, in comparison to known methods, in which supply at a low heat energy or a low UV light crosslink. Due to the thus possible processing at low temperatures, at most sensitive tissue can be spared. Furthermore, the energy consumption is advantageously reduced and is in relation to the plastic melts a more pleasant working environment allows.

FIG. 3 shows an example of the coating device 22 in a further schematic view. In addition to the example shown in FIG. 2, the supplied fibers of the conductive fabric 18 are preheated by passing through a preheating station 46. This preheating station 46 comprises a plurality of preheating elements 48 - 48, which preheat the inner surface and outer surface of the conductive fabric 18, for example by means of infrared rays. By preheating the fibers of the conductive fabric 18, the subsequent connection with the liquid coating material 32 is supported. In addition, an air knife 50 is provided which is pressed directly onto the conductive fabric 18 during the coating, so that the coating thickness is thereby adjusted. Downstream of the air knife 50, a roller blade 52 is provided, which is pressed onto the coated conductive fabric 36 and thereby removes excess coating material. Thus, a desired coating thickness can be set just as reliably. The roller blade 52 is formed corresponding to the outer shape of a counterpart 54 arranged on the opposite side (outer side), which has a substantially circular outer surface. Therefore, to substantially conform to this outer surface, the squeegee 52 assumes a substantially J-shape ("J-squeegee").

For subsequent cross-linking, the conductive fabric 36, coated with an ideal layer thickness, passes through the cross-linking device 38 and is exposed to infrared radiation by infrared radiators 40 to 40 for cross-linking. In order to further reliably protect the inner line 26, which is guided in the cylindrical separating element 44, against heat input by the infrared radiators 40 to 40, the cylindrical separating element 44 flows through supply air 56 inside it (as indicated schematically by arrows 56). For this purpose, the separating element 44 is hollowed out in the longitudinal direction or double-layered. The direction of flow of the supply air 56 corresponds to the feed direction V. The supply air 56 emerging at the end of the cylindrical separating element 44 then passes through the cross-linking device 38 in the opposite direction and flows in sections along the coated conductor fabric 36, which additionally promotes cross-linking. The heated exhaust air 58 of this supply air 56 flow is then removed upward from the coating device 22.

Claims (13)

A method of manufacturing a conduit (12), comprising: Weaving a plurality of fibers (16, 16) into a conductive fabric (18); Conveying the conductive fabric (18) in a feed direction (V); Applying a liquid coating material (32) to the inner surface and / or outer surface of the woven power fabric (18); and Bonding the applied liquid coating material (32) to the conductive fabric (18). 2. The method of claim 1, wherein the liquid coating material (32) is annularly applied to the in the feed direction (V) moving conductive fabric (18). 3. The method of claim 1 or 2, wherein bonding the applied liquid coating material (32) to the conductive fabric (18) comprises flowing the fibers (16, 16) with the liquid coating material (32) and then curing it , 4. The method of claim 1, wherein the coating material comprises silicone, polyurethane or polyurea. A method according to any one of the preceding claims, wherein the layer thickness of the applied liquid coating material (32) is adjusted at at least one point downstream of the application via knife coating or calendering. The method of any one of the preceding claims, further comprising penetrating the conduit web (18) with the liquid coating material (32) by applying a vacuum to the conduit web (18) at a location thereof across the conduit web (18) of the site for applying the liquid coating agent (32) at least partially opposite. A method according to any one of the preceding claims, further comprising tempering the fibers (16, 16) upstream of the coating and / or the coated conductive fabric (36) downstream of the coating. 8. The method according to any one of the preceding claims, further comprising passing a separate inner line (26) within the line fabric (18) along its feed direction (V). 9. Apparatus (10) for producing a conduit (12), comprising: weaving means (14) for weaving a plurality of fibers (16, 16) into a conductive fabric (18); a conveyor for conveying the conductive fabric (18) in a feed direction (V); an applicator element (30) for applying a liquid coating material (32) to at least the inner surface and / or outer surface of the conductive fabric (18); and a crosslinking device (38) for crosslinking the applied liquid coating material (32) with the conductive fabric (18). The apparatus of claim 9, further comprising vacuum means (34) for applying a negative pressure to the conductive fabric (18) at a location thereof opposite at least in portions over the conductive fabric (18) to the liquid coating material application site (32). A device according to claim 9 or 10, wherein the coating material (32) comprises silicone, polyurethane or polyurea. 12. conduit (12) which is made by a method according to any one of claims 1 to 8. 13. geothermal probe with a line (12) according to claim 12 for use in geothermal energy.