Pipe for providing fibres with a binding agent, and arrangement of pipes

Abstract

The invention relates to a pipe (1) for providing fibres with a binding agent, wherein the pipe (1) has an inlet opening (2) for blowing in the fibres and an outlet opening (3) for blowing out the fibres and an intermediate pipe section (4) having a plurality of feed openings (5) which open into the pipe section (4) and are provided in order to conduct a binding agent into the pipe section (4) and to provide fibres blown therein with the binding agent, wherein the pipe section (4) has, in the region of the feed openings (5), at least in some portions, a non-round guide cross-section (6) and / or in that at least two feed openings (5) are distributed around the circumference of the pipe section (4) and are arranged such that each of the opening cross sections (7) thereof at least partly overlap with respect to a longitudinal axis (8) of the pipe section (4).

Description

[0001] Pipe for applying a binding agent to fibers and arrangement of pipes

[0002] Description

[0003] The invention relates to a tube for providing fibers with a binding agent and an arrangement of at least two tubes.

[0004] In the industrial production of composite components, fibers are typically used, which must be coated with a binder. The fibers are then often further processed under pressure and heat to obtain the desired composite component. When coating the fibers with the binder, it is desirable that the binder is distributed as homogeneously as possible between the fibers, as this has a significant influence on the mechanical properties of the composite component.

[0005] A pipe of the type mentioned above is frequently used to coat the fibers with the binding agent. This pipe has an inlet opening for blowing in the fibers and an outlet opening for blowing out the fibers, as well as an intermediate pipe section. This pipe section has multiple feed openings that lead into it and are designed to direct the binding agent into the pipe section, thereby coating the fibers blown into it with the binding agent.

[0006] One disadvantage of conventional pipes is that fibers located in the outer cross-sectional area of ​​the pipe section are typically more heavily impregnated with binder than fibers located in the inner cross-sectional area. While it is possible to reduce the flow velocity of the fibers in the pipe section or increase the binder supply pressure to ensure better distribution of the binder within the fibers, this leads to increased energy consumption. This, in turn, negatively impacts the operating costs of the respective systems used.

[0007] It is an object of the present invention to propose a tube and an arrangement of tubes by means of which fibers can be uniformly supplied with binder and with which high plant productivity can be achieved at low cost.

[0008] The problem is solved by means of a pipe according to claim 1 and an arrangement of at least two pipes according to claim 15. Advantageous embodiments are the subject of dependent subclaims.

[0009] The tube according to the invention is suitable, in a manner known per se, for providing fibers with a binding agent. For this purpose, the tube has an inlet opening for blowing in the fibers and an outlet opening for blowing out the fibers. An intermediate tube section has a plurality of feed openings that open into the tube section and are designed to guide a binding agent into the tube section and to provide the fibers blown in therein with the binding agent.

[0010] It is within the scope of the invention that the pipe section in the area of ​​the feed openings has at least a section with a non-circular guide cross-section.

[0011] In addition to or as an alternative to the feature that the pipe section has at least a section of a non-circular guide cross-section in the area of ​​the feed openings, at least two feed openings are distributed circumferentially on the pipe section and arranged in such a way that their respective opening cross-sections overlap at least partially with respect to a longitudinal axis of the pipe section.

[0012] The invention is based on the finding that, through a suitable design of the tube and / or the positions of the feed openings, it is possible to uniformly coat fibers with binder, thereby achieving the desired fiber throughput while simultaneously keeping operating costs low. The invention provides at least two different measures for this purpose, which can be implemented in combination or alternatively.

[0013] According to the invention, the pipe can be designed with a non-circular guide cross-section. A non-circular guide cross-section is advantageous within the scope of the invention because the fibers blown into the pipe section can distribute themselves across the guide cross-section, allowing both the outer and inner fibers to be coated with binder, resulting in a homogeneous distribution of the binder. This is particularly effective with regard to the outer fibers because they are located near the feed openings when the binder is introduced and can therefore be easily coated and completely saturated with the binder.Regarding the internal fibers, good penetration can be achieved particularly well if the feed openings on the pipe section are arranged circumferentially in such a way that their distance to the geometric center of the guide cross-section is shorter compared to a circular guide cross-section. This means the binding agent has to travel a correspondingly shorter path to reach and penetrate the internal fibers.

[0014] In particular, the guide cross-section is not circular. The invention is not fundamentally limited to the geometric features used to create the non-circular guide cross-section. Rather, the guide cross-section can have varying distances from its geometric center point to an outer contour along its circumference. The guide cross-section can, in particular, have common shapes such as elliptical, rectangular, square, triangular, polygonal, or a combination thereof.

[0015] As explained above, in addition to or as an alternative to a non-circular guide cross-section, at least two feed openings can be distributed around the circumference of the pipe section and arranged such that their respective opening cross-sections overlap at least partially with respect to a longitudinal axis of the pipe section. It is advantageous that such a pipe design can also be implemented with a fundamentally arbitrary guide cross-section, in particular with both a circular and a non-circular guide cross-section, for example, an elliptical, rectangular, square, triangular, polygonal guide cross-section, or a combination thereof.

[0016] The design of the tube according to the invention, in which the feed openings are arranged such that they overlap with respect to the longitudinal axis of the tube section, is advantageous because fibers can be supplied with binding agent in a large quantity as required and from different directions.

[0017] Within the scope of the invention, the tube can be understood as a hollow body suitable for conveying liquids and / or gases and / or vapors and / or loose solids and / or a combination thereof. In particular, the tube is designed to convey wood fibers, plastic fibers, or glass fibers. The binder can be a resin, such as urea-formaldehyde (UF), an adhesive such as methylene diphenyl diisocyanate (MDI), a bio-adhesive, a melamine-reinforced urea-formaldehyde (MUF), a phenolic adhesive (PF), or a hybrid adhesive. The binder can also include hardeners, for example, polyols, which can be used with the aforementioned methylene diphenyl diisocyanate (MDI) or urea-formaldehyde (UF) adhesives. The use of ammonium compounds such as ammonium nitrate, ammonium sulfide, or ammonium chloride as binders is also conceivable.

[0018] Within the scope of the invention, the guide cross-section can be limited by the inner contour of the pipe section. The guide cross-section can lie in a plane that extends substantially orthogonally to the longitudinal axis of the pipe section.

[0019] Within the scope of the invention, a feed opening can be understood as a radially arranged recess in the pipe section. It is within the scope of the invention that such a recess, either directly or by means of an additional feed element, such as an inlet nozzle, is designed to guide the binding agent into the pipe section. Such a feed element can be detachably or permanently arranged in such a recess.

[0020] In an embodiment of the invention in which the opening cross-sections of the feed openings are arranged to overlap with respect to the longitudinal axis of the pipe section, it is within the scope of the invention that these overlap completely or only partially.

[0021] In particular, the pipe according to the invention has a preferred installation position in which none of the feed openings are open in the direction of gravity and, in particular, their respective opening axes are oriented outside an angular range of ±30°, preferably ±20°, and most preferably ±10°, relative to the direction of gravity. Specifically, the feed openings in the area specified above are oriented such that the direction of gravity through any of the feed openings is not directed from the interior of the pipe towards the surrounding area. This preferred installation position is based on the understanding that feed openings open in the direction of gravity, which may be located, for example, on the underside of a substantially horizontal pipe section, can become clogged with fibers relatively easily. The installation position described above easily avoids this disadvantage.The preferred installation position can be expressed on the pipe according to the invention by the design of a connection area which is intended for connecting the pipe to another system element, in particular another pipe. In particular, the invention thus also relates to a system for providing fibers with a binding agent, which includes a pipe according to the invention or an advantageous embodiment thereof.

[0022] In an advantageous embodiment, the pipe section has, at least in sections, a guide cross-section with an oval, in particular an elliptical, preferably superelliptical contour. Along a major axis, the guide cross-section has a larger dimension than along a minor axis.

[0023] Investigations by the applicant have shown that the aforementioned guide cross-sections lead to particular advantages with regard to the fluid dynamic interactions between the fibers and the binder and, in particular, promote a homogeneous penetration of the fibers with the binder.

[0024] An oval guide cross-section can generally be considered any rounded, elongated circumferential contour resembling a circle, whose cross-sectional dimensions differ along the major and minor axes. In other words, this includes geometries with rounded contours, without requiring a specific ratio between the dimensions along the major and minor axes.

[0025] An elliptical guide cross-section has a contour that can be defined by a closed curve, which is formed when a cone is intersected by a plane inclined to the cone's axis. The contour has its longest diameter along the major axis and its shortest along the minor axis. In particular, the ellipse is symmetrical with respect to its major and minor axes and represents a specific form of oval.

[0026] A superelliptical guide cross-section, also called a superellipse or lame curve, extends the elliptical geometry of the ellipse described above by introducing a shape parameter that influences the curvature of the contour. The equation of a superellipse is I ” | n + | | n= 1 where a and b are the semi-axes and n is an exponent. For n = 2, a perfect ellipse is obtained. If n is chosen greater than 2, the guide cross-section has an increasingly rectangular contour with rounded corners. If n is chosen less than 2, the guide cross-section has an increasingly rounded contour compared to an ellipse. It is within the scope of advantageous further development that n is less than or greater than 2, or equals 2.

[0027] The contours described here can be completely closed, at least in sections, or they can be interrupted in sections by the opening cross-section of one of the feed openings. Therefore, it is advantageous for the guide cross-section to only partially exhibit one of the contours mentioned here. In an advantageous embodiment, at least one of the feed openings and / or an inlet nozzle arranged thereon has an opening axis that runs parallel to, or at an angle of no more than 45 degrees to, the secondary axis of the guide cross-section.

[0028] Investigations by the applicant have shown that the aforementioned orientations of the opening axis can lead to advantages in the penetration of the fibers with the binder. In particular, the orientation of the feed opening can optionally be substantially 0°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, or 45°. Such an orientation of the feed opening is particularly conceivable if the guide cross-section is oval, elliptical, or superelliptical. In particular, the orientations of the feed openings and their opening axes are selected such that they are substantially orthogonal to the outer surface of the tube section or are oriented independently of the outer surface.

[0029] In an advantageous embodiment, at least two feed openings and / or an inlet nozzle arranged thereon are arranged on opposite sides of the pipe section, preferably symmetrically with respect to the main axis and / or secondary axis of the guide cross-section.

[0030] According to the aforementioned refinement, it is advantageous for the feed openings to be arranged opposite each other. This makes it possible, in particular, to introduce binder into the fiber material from two different sides, thus achieving homogeneous penetration of the fibers with the binder. It is within the scope of this advantageous refinement that the feed openings, with their opening axes, are each arranged essentially parallel to the main or secondary axis of the guide cross-section. It is also conceivable that the feed openings, with their opening axes, are oriented non-parallel to each other.

[0031] In an advantageous embodiment, the at least two feed openings and / or inlet nozzles arranged thereon are offset from each other with their respective opening axes along the main axis of the oval contour and / or inclined about the longitudinal axis of the pipe section, the opening axes preferably running parallel to each other.

[0032] According to the embodiment described above, the feed openings can be arranged and / or oriented essentially symmetrically to each other with respect to a surface center of the guide cross-section. It is advantageous for the opening axes to each run essentially parallel to the secondary axis, but offset along the primary axis parallel to the secondary axis. It is also conceivable that the opening axes are not oriented parallel to the secondary axis, but are each inclined at an angle between 0° and 45° inclusive relative to the secondary axis, while remaining parallel to each other.These design measures prevent the feed openings from being directly and completely opposite each other, thus preventing the binding agent from one feed opening from being introduced into the pipe section directly opposite the conveying direction of an immediately opposite feed opening. This improves the efficiency of coating the fibers with the binding agent.

[0033] In an advantageous embodiment, the feed openings are distributed circumferentially around the pipe section and arranged such that their respective opening cross-sections are arranged without overlap with respect to a longitudinal axis of the pipe section. The at least two feed openings, and in particular more than two feed openings, are arranged in pairs at an angle to each other around the longitudinal axis of the pipe section.

[0034] In other words, the feed openings can be arranged along a spiral or curved path on the pipe section. It is conceivable that the feed openings are angularly offset from each other in pairs by an angle around the longitudinal axis, for example, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90°. Such a pipe configuration can be provided, in particular, if the pipe section has a non-circular guide cross-section, at least partially, in the area of ​​the feed openings. This configuration can also be provided in combination with an arrangement of feed openings that have overlapping cross-sections with respect to the longitudinal axis of the pipe section.

[0035] In an advantageous embodiment, the guide cross-section has at least a section with a polygonal contour with at least three, in particular four, preferably five, most preferably more than five essentially straight sides, on which the at least two feed openings are arranged, wherein in particular one of the straight sides is provided with one of the feed openings.

[0036] The embodiments described above are advantageous because the fibers blown into the pipe section can distribute themselves across the guide cross-section, allowing both the outer and inner fibers to be coated with binding agent. With regard to the outer fibers, this is achieved because they are located near the feed openings when the binding agent is introduced and can therefore be easily coated and completely saturated with the agent. With regard to the inner fibers, good penetration is achieved because the feed openings on the straight sides are located at a shorter distance from the geometric center of the guide cross-section compared to a circular cross-section.This means that the binder has to travel a shorter distance to reach the inner fibers, thus enabling a homogeneous distribution of the binder across the guide cross-section.

[0037] In an advantageous further development, the inlet opening and / or the outlet opening are each essentially circular. Between the inlet opening and the pipe section with the non-circular guide cross-section, and / or between the outlet opening and the pipe section with the non-circular guide cross-section, at least one compensating section with a continuous cross-sectional transition is formed.

[0038] The circular cross-sections of the inlet and / or outlet openings allow the pipe to be connected to standard industrial fittings and enable the insertion and removal of fibers. This results in excellent compatibility with other system components. Specifically, the cross-sectional area of ​​the inlet and / or outlet opening can be larger or smaller than the cross-sectional area of ​​the pipe section.

[0039] In an advantageous embodiment, the pipe has at least one auxiliary opening, which is provided for the installation of a pressure and / or flow measuring device or for the introduction of an auxiliary substance. In particular, the auxiliary opening can be located in the pipe section in which the feed openings are also located, or in an upstream and / or downstream section, for example, in the equalization section between the pipe section and the inlet opening and / or the outlet opening. In an advantageous embodiment, a flow-guiding structure is arranged in the pipe section. The flow-guiding structure can, in principle, be any fluid-technical element, component, or assembly, each of which is suitable for guiding the fibers and / or the binder within the pipe section, in particular along the longitudinal axis of the pipe section or transversely thereto.The flow-guiding structure can be detachably integrated within the pipe section, i.e., structurally separate from the pipe. It is also conceivable that the flow-guiding structure is permanently, preferably integrally, connected to the pipe, particularly the pipe section.

[0040] In an advantageous embodiment, the flow-guiding structure comprises a swirl generator and / or flow guide and / or vortex generator. The aforementioned swirl generators and / or flow guides and / or vortex generators can be designed and arranged within the pipe section to influence the distribution of the fibers and / or the binder within that section. In particular, this can be achieved by means of such a flow-guiding structure by affecting the flow characteristics, especially the flow direction and / or flow velocity, of the injected fibers and / or the binder.

[0041] In an advantageous embodiment, the flow-guiding structure can at least partially define the non-circular guide cross-section. In particular, it is conceivable that the pipe has a circular cross-section in the pipe section itself, but the flow-guiding structure subdivides the pipe section in such a way that the guide cross-section is partially bounded by the flow-guiding structure itself and partially by the inner wall of the pipe. For this purpose, the flow-guiding structure can, in particular, comprise an elongated web arranged in the pipe section, as well as a plurality of walls, in particular at least three, arranged between the web and an inner surface of the pipe section. These walls spatially subdivide the pipe section into several, in particular at least three, guide chambers, at least one of which has the non-circular guide cross-section.

[0042] Additionally or alternatively, the flow-guiding structure can comprise at least one profile body arranged on the inside of the pipe section and having at least one surface oriented, at least partially, parallel to the opening axis of one of the feed openings and / or an inlet nozzle arranged thereon, and designed to guide the binder into the pipe section. In particular, it is conceivable that two such profile bodies are arranged circumferentially next to a feed opening and define a channel extending substantially radially from the feed opening into the pipe section.

[0043] In an advantageous embodiment, the pipe section has a varying guide cross-section along its longitudinal axis. In particular, the guide cross-section can vary such that the pipe section has at least two areas, each of which has an oval, elliptical, or superelliptical cross-section or a polygonal cross-section with at least three, in particular four, preferably five, and most preferably more than five substantially straight sides.

[0044] In an advantageous embodiment, the tube has more than two, preferably three, in particular four, preferably more than four, and most preferably eight feed openings arranged circumferentially on the tube. It is advantageous in this embodiment that the feed openings are arranged in a common area with respect to the longitudinal axis of the tube section, in particular such that their opening cross-sections overlap with respect to the longitudinal axis. In an advantageous embodiment, the tube is manufactured by forming, in particular internal high-pressure forming or primary forming, in particular casting and / or 3D printing, or in the manner of a tailored tube.Investigations by the applicant have shown that the aforementioned manufacturing processes offer surprising advantages with regard to the advantageous geometries and dimensions of the tube, particularly concerning mechanical stiffness and abrasion resistance of the tube's inner surface. Specifically, the tube is made of manganese steel or duplex steel.

[0045] In an advantageous embodiment, the pipe is curved at least partially along its longitudinal axis. In particular, two adjacent pipe sections can have a curvature angle between them that lies between 0° and 90°. Specifically, the curvature angle can be 10°, 20°, 30°, 40°, 45°, 50°, 60°, 70°, or 80°. The curvature angle can be defined as the angle between the two central axes of two adjacent pipe sections. The curvature angle can have a continuous profile along the longitudinal axis of the pipe, particularly in the area of ​​the guide cross-section, so that blown-in fibers can be guided fluid-efficiently along the inner wall of such a curved pipe. Preferably, the pipe has a periodic curvature profile along its longitudinal axis, particularly in the form of a wave-like or S-shaped profile.

[0046] It is within the scope of the invention that several pipes can be connected to each other and in particular be identically designed and preferably be twisted relative to each other with respect to their respective longitudinal axes.

[0047] As mentioned above, the object of the invention is also achieved by an arrangement according to claim 16. This arrangement comprises at least two pipes which are connected to each other via an intermediate element in a flow-conducting manner, wherein the intermediate element is configured in particular with a deflection angle between 0 and 45° and / or with an S-shaped profile. The pipes are configured according to the invention or according to an advantageous embodiment of the invention.

[0048] Accordingly, the descriptions of the tube according to the invention and its advantageous further developments apply mutatis mutandis to the conceivable embodiments of the tubes and the associated advantages. If required, the at least two tubes can be rotated relative to each other with respect to their longitudinal axes and, in particular, can be identical in design.

[0049] Exemplary embodiments of the invention and the advantages achievable therewith are explained below with reference to exemplary embodiments and the figures. These show

[0050] Figure 1 shows a first embodiment of a tube in side view and sectional view AA;

[0051] Figure 2 shows a second embodiment of a tube in side view and sectional view AA;

[0052] Figure 3 shows a third embodiment of a tube in side view and sectional view AA;

[0053] Figure 4 shows a fourth embodiment of a tube in side view and sectional view AA;

[0054] Figure 5 shows a fifth embodiment of a tube in side view and sectional view AA;

[0055] Figure 6 shows a sixth embodiment of a tube in perspective view; Figure 7 shows the sixth embodiment of a tube in side view and sectional views AA, BB and CC.

[0056] In the industrial production and processing of composite materials, fibers are typically used, which must be bonded with a binder before being processed into the desired end component using force and heat. These fibers can be, for example, wood fibers, plastic fibers, or glass fibers. Suitable binders include urea-formaldehyde (UF), methylenediphenyl diisocyanate (MDI), or bio-based or hybrid adhesives. The binder can also include hardeners, such as polyols, which can be used with MDI or modified urea-formaldehyde (UF) adhesives. The use of ammonium compounds such as ammonium nitrate, ammonium sulfide, or ammonium chloride as binders is also conceivable.

[0057] It is desirable to distribute the binder as evenly as possible between the fibers, as this is crucial for the mechanical properties of the component being manufactured. Furthermore, it is desirable to achieve the highest possible fiber throughput while simultaneously minimizing energy consumption.

[0058] Figures 1 to 7 show different embodiments of tubes 1, each having an inlet opening 2 for blowing in the fibers and an outlet opening 3 for blowing out the fibers, as well as an intermediate tube section 4 with a plurality of feed openings 5. The feed openings 5 ​​open into the tube section 4 and are designed to guide the binding agent into the tube section and to coat the fibers blown in therein with the binding agent. As explained in detail below, the tube sections 4 of the tubes 1 have, at least partially, a non-circular guide cross-section 6 in the area of ​​the respective feed openings 5. Additionally or alternatively, at least two feed openings 5 ​​are distributed circumferentially around the tube section 4 and arranged such that their respective opening cross-sections 7 overlap at least partially with respect to a longitudinal axis 8 of the tube section 4.Studies have shown that at least one of these constructive measures leads to advantages in terms of the desired binder distribution in the fibers as well as in terms of process efficiency.

[0059] Figure 1 shows a first embodiment of a tube 1 which has a non-circular guide cross-section 6 in the tube section 4. As shown in the sectional view AA of Figure 1, the guide cross-section 6 has a substantially elliptical contour with larger dimensions along a major axis 9 than along a minor axis 10. The contour of the guide cross-section 6 is essentially defined by the inside of the tube 1 in the tube section 4 and is interrupted section by the feed openings 5 ​​and their opening cross-sections 7.

[0060] As also shown in the sectional view AA of Figure 1, the feed openings 5 ​​are arranged in pairs opposite each other in the pipe section. In the embodiment shown here, the feed openings 5 ​​are formed by inlet nozzles whose respective opening axes (not shown) are oriented essentially parallel to the secondary axis 10.

[0061] The side view of the tube 1 according to Figure 1 shows that the feed openings 5 ​​with their respective opening cross-sections 7 are arranged along the longitudinal axis 8 of the tube 1 such that they overlap. For clarity, only one of the feed openings 5 ​​with its opening cross-section 7 is labeled. If fibers (not shown) are blown into the tube section 4 through the inlet opening 2, they can be supplied with binder (not shown) from different sides via the feed openings 5. The elliptical geometry of the tube section 4 enables particularly good penetration of the fibers by the binder. Compared to a circular guide cross-section, the embodiment shown in Figure 1 has the advantage that the path of the binder from the feed openings 5 ​​to the geometric center of the guide cross-section 6, where the main and secondary axes 9 and 10 intersect, respectively, is shortened.This makes it possible in particular to provide those fibers in pipe section 4 with binding agent that are located and compacted inside pipe section 4.

[0062] The inlet opening 2 and the outlet opening 3 each have a substantially circular cross-section, which gives the pipe 1 good compatibility for connection with other flow-conducting elements that also typically have circular cross-sections. The compensating sections 11 are arranged between the inlet and outlet openings 2 and 3, respectively, and each has a continuous cross-sectional transition between the inlet opening 2 and the outlet opening 3.

[0063] Figure 2 shows a second embodiment of a pipe 1, which serves the same purpose as explained at the outset with regard to the embodiments shown here. Similar to the first embodiment shown in Figure 1, the pipe 1 according to Figure 1 has a non-circular guide cross-section. This can be seen from sectional view AA of Figure 2. In contrast to the embodiment shown in Figure 1, however, the pipe 1 according to Figure 2 has a circular cross-section in the pipe section 4 itself. A flow-guiding structure 12 is arranged within the pipe section. The flow-guiding structure 12 comprises an elongated web 13 and three plurality of walls 14, which are arranged between the web 13 and an inner surface of the pipe section 4. The walls spatially divide the pipe section 4 into three guide chambers, at least one of which has the non-circular guide cross-section 6.The feed openings 5 ​​are distributed around the circumference of the pipe section 4 such that the opening cross-sections 7 do not overlap with respect to the longitudinal axis 8 of the pipe section. As can be seen from the side view of the pipe 1 in Figure 2, the web 13 is tapered at its ends. This facilitates the flow of fibers into and out of the guide chambers. Otherwise, the descriptions in Figure 1 apply accordingly.

[0064] Figure 3 shows a third embodiment of a tube 1, which also serves to coat fibers with a binding agent. According to the third embodiment as well, the tube 1 has a non-circular guide cross-section 6.

[0065] Similar to the second embodiment shown in Figure 2, the third embodiment of the pipe 2 has a flow-guiding structure 12 inside the pipe section. In contrast to the embodiment shown in Figure 2, the flow-guiding structure 12 comprises several profile bodies 15, each arranged on the inside of the pipe section 4. The profile bodies 15 each have surfaces that run parallel to the opening axes of the inlet nozzles of the feed openings 5. Thus, the profile bodies 15 define a channel 16 in pairs, which runs essentially radially and allows binders to be fed into the pipe section 4 via the feed openings 5.

[0066] As can be seen from the side view of the pipe 1 in Figure 3, the profile bodies 15 are designed at their end faces, which point towards the inlet opening 2 and the outlet opening 3 respectively, such that they narrow the guide cross-section 6 in the area of ​​the feed openings 5 ​​compared to an upstream section. This allows blown-in fibers to be compacted, which can have an advantageous effect on their impregnation with binder. The details shown in Figures 1 and 2 apply accordingly.

[0067] Figure 4 shows a fourth embodiment of the tube 1, whose guide cross-section 6 has a substantially circular contour. Circumferentially, the tube 1 is provided in the tube section 4 with a total of four feed openings 5, which are positioned along the longitudinal axis 8 such that their opening cross-sections overlap along the longitudinal axis 8. Up to eight feed openings can be provided, overlapping along the longitudinal axis 8. This allows fibers blown into the tube section 4 to be simultaneously coated with binding agent from several sides. Otherwise, the embodiments shown in Figures 1 to 3 apply accordingly.

[0068] Figure 5 shows a fifth embodiment of the tube 1, whose guide cross-section 4 has a substantially polygonal, rectangular contour with four straight sides 17, on each of which several feed openings 5 ​​are arranged. For clarity, only one of the straight sides 17 and only one of the feed openings are labeled. Four of the feed openings 5, each comprising an inlet nozzle, are distributed circumferentially around the tube section 4 such that their opening cross-sections overlap along the longitudinal axis 8. Otherwise, the descriptions in Figures 1 to 4 apply accordingly.

[0069] Figure 6 shows a sixth embodiment of the pipe 1. As explained in detail with reference to Figure 7, the pipe shown in Figure 6 has a guide cross-section 6 in pipe section 4, which has an elliptical contour. Pipe section 4 lies between the inlet opening 2 and the outlet opening 3 and is fluidically connected to them via the compensating sections 11. Several feed openings 5 ​​are arranged in pipe section 4. An auxiliary opening 18 is also arranged between the inlet opening 2 and pipe section 4, which is provided for the installation of a pressure and / or flow measuring device or can also serve for the introduction of an auxiliary substance. Such an auxiliary opening can also be implemented in all other embodiments of the pipe 1 shown in Figures 1 to 5.

[0070] Figure 7 shows the sixth embodiment of the tube 1 in a side view as well as in sectional views AA, BB, CC. The descriptions of Figure 6 apply accordingly to Figure 7.

[0071] Sectional view AA of Figure 7 corresponds to a frontal view of the tube 1 along the longitudinal axis 8, with the tube cut at the level of the auxiliary opening 18. Sectional view AA shows that the tube 1 has a guide cross-section 6 with a circular contour at the level of the auxiliary opening 18.

[0072] Sectional view BB of Figure 7 shows that the pipe 1 in pipe section 4 has a guide cross-section 6 with an elliptical contour. Analogous to the descriptions of the first embodiment shown in Figure 1, the guide cross-section 6 has a larger dimension along a major axis 9 than along a minor axis 10. The feed openings 5, with the inlet nozzle arranged thereon, each have an opening axis 19, which, in the sixth embodiment shown here, runs at an angle of approximately 15 degrees to the minor axis 10. Two of the feed openings 5 ​​are arranged on opposite sides of the pipe section 4. The opposite feed openings 5 ​​are aligned parallel to each other with respect to their 19 opening axes and offset from each other along the major axis 10.In this respect, there is symmetry with respect to the main axis 9 and the secondary axis 10 of the guide cross-section 6. Sectional view CC of Figure 7 shows another front view of the tube along the longitudinal axis 8, to which the same considerations apply as with respect to sectional view BB, wherein the arrangements of the opposing feed openings 5 ​​are reversed, in particular symmetrically mirrored on the secondary axis 10.

[0073] In a manner not shown here, the pipes 1 according to Figures 1 to 7 can be connected to each other in pairs via an intermediate element in a flow-conducting manner. Such an intermediate element can have a deflection angle between 0 and 45° and / or be S-shaped. It is also conceivable that at least two of the pipes 1 connected to each other via such an intermediate element are twisted relative to each other with respect to their longitudinal axes 8.

Claims

Claims 1. Pipe (1) for applying a binding agent to fibers, wherein the pipe (1) has an inlet opening (2) for blowing in the fibers and an outlet opening (3) for blowing out the fibers, and an intermediate pipe section (4) with a plurality of feed openings (5) which open into the pipe section (4) and are provided for guiding a binding agent into the pipe section (4) and for applying the binding agent to fibers blown in therein, characterized in that the pipe section (4) has at least a section of a non-circular guide cross-section (6) in the area of ​​the feed openings (5) and / or that at least two feed openings (5) are distributed circumferentially on the pipe section (4) and are arranged such that their respective opening cross-sections (7) overlap at least partially with respect to a longitudinal axis (8) of the pipe section (4).

2. Tube (1) according to claim 1, wherein the guide cross-section (6) has an oval, in particular elliptical, preferably superelliptical contour and the guide cross-section (6) has a larger dimension along a principal axis (9) than along a minor axis (10).

3. Tube (1) according to claim 2, wherein at least one of the feed openings (5) and / or an inlet nozzle arranged thereon has an opening axis (19) which runs parallel or at an angle of at most 45 degrees to the secondary axis (10) of the guide cross-section (6).

4. Pipe (1) according to claim 3, wherein at least two feed openings (5) and / or an inlet nozzle arranged thereon are arranged on opposite sides of the pipe section (4), preferably symmetrically with respect to the main axis (9) and / or secondary axis (9) of the guide cross-section (6).

5. Tube (1) at least according to claim 4, wherein the at least two feed openings (5) and / or inlet nozzles arranged thereon are offset from each other with their respective opening axes (19) along the main axis (9) of the oval contour, wherein the opening axes (19) preferably run parallel to each other.

6. Pipe (1) according to one of the preceding claims, wherein the feed openings (5) are distributed circumferentially on the pipe section (4) and are arranged such that their respective opening cross-sections are arranged without overlap with respect to a longitudinal axis (8) of the pipe section (4), wherein the feed openings (5), in particular more than two feed openings (5), are arranged in pairs at an angle to each other about the longitudinal axis (8) of the pipe section (4).

7. Tube (1) according to one of the preceding claims, wherein the guide cross-section (6) has at least partially a polygonal contour with at least three, in particular four, preferably five, most preferably more than five substantially straight sides (17) on which the at least two feed openings (5) are arranged, wherein in particular one of the straight sides (17) is provided with one of the feed openings (5).

8. Pipe (1) according to one of the preceding claims, wherein the inlet opening (2) and / or the outlet opening (3) are each substantially circular and at least one compensating section (11) with a continuous cross-sectional transition is formed between the inlet opening (2) and the pipe section with the non-circular guide cross-section (6) and / or between the outlet opening and the pipe section (4) with the non-circular guide cross-section (6).

9. Pipe (1) according to claim 8, wherein the pipe (1) has at least one auxiliary opening (18) which is provided for the arrangement of a pressure and / or flow measuring device or for the introduction of an auxiliary substance.

10. Pipe (1) according to one of the preceding claims, wherein a flow-guiding structure (12) is arranged in the pipe section (4), wherein preferably the flow-guiding structure (12) comprises a swirl generator and / or flow guide and / or vortex generator, and / or wherein preferably the flow-guiding structure (12) defines at least partially the non-circular guide cross-section (6).

11. Pipe (1) at least according to claim 10, wherein the flow-guiding structure (12) comprises an elongated web (13) which is arranged in the pipe section (4), and a plurality of walls (14), in particular at least three, which are arranged between the web (9) and an inner side of the pipe section (4) and the walls (14) spatially divide the pipe section (4) into several, in particular at least three, guide chambers, at least one of which has the non-circular guide cross-section (6).

12. Pipe (1) at least according to claim 10, wherein the flow-guiding structure (12) comprises at least one profile body (15) which is arranged on an inside of the pipe section and has at least one surface which is oriented at least partially parallel to the opening axis (19) of one of the feed openings (5) and / or an inlet nozzle arranged thereon and is provided to guide the binder into the pipe section (4).

13. Pipe (1) according to one of the preceding claims, wherein the pipe section (4) has a varying guide cross-section along the longitudinal axis and / or wherein more than two, preferably three, in particular four, preferably more than four, most preferably eight feed openings (5) are arranged circumferentially on the pipe (1).

14. Tube (1) according to one of the preceding claims, which is manufactured at least partially by forming, in particular internal high-pressure forming or primary forming, in particular casting and / or 3D printing or in the manner of a tailored tube, and / or which is manufactured at least partially from manganese steel or duplex steel, and / or which is curved along the longitudinal axis.

15. Arrangement of at least two tubes (1), each configured according to one of the preceding claims and connected to each other via an intermediate element in a flow-conducting manner, wherein the intermediate element is in particular configured with a deflection angle between 0 and 45° and / or with an S-shaped profile.

16. Arrangement according to claim 15, wherein the at least two tubes (1) are twisted relative to each other with respect to their longitudinal axes.

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