APPARATUS FOR MANUFACTURING PIPE SECTIONS AND METHOD FOR MANUFACTURING PIPE SECTIONS - Patent application

Abstract

The present invention relates to an apparatus for producing an insulated pipe section, the apparatus comprising a rotatable longitudinal mandrel configured to receive uncured mineral wool and wind it around the mandrel to produce an insulated pipe section, a belt, preferably an endless belt, at least two longitudinal jaws engaging the belt, the longitudinal jaws configured to surround the mandrel by the belt, and a mandrel control element configured to actively control the lateral movement of the mandrel.

Description

[Technical field]

[0001] The present invention relates to an apparatus for manufacturing an insulated pipe section and to a method for manufacturing an insulated pipe section. Whenever the terms "pipe section" or "insulating pipe section" are used in this specification, they mean a tubular element made of thermal and / or acoustic insulation material. [Background technology]

[0002] As an insulating pipe conveying a fluid such as a liquid or gas having a temperature different from the temperature of the surroundings, a pipe section made of insulating material is a good solution. The pipe section will also prevent condensation in pipes conveying cold fluids. The insulating pipe section can be made from various insulating materials such as mineral wool (glass wool, stone wool), polymeric foam, foamed glass, etc. GB1503644 discloses a pipe section winding machine, in which the pipe section is produced by winding a web of uncured mineral wool around a mandrel placed in a loop of an endless belt, and then curing the wound mineral wool. The diameter of the loop is controlled by a movable member as a function of the linear speed of the belt and the length and weight per unit of the fibrous web. In this machine, as the diameter of the wound pipe section increases, the mandrel for the pipe section may move in a slot in an uncontrolled manner. Summary of the Invention [Problem to be solved by the invention]

[0003] In view of the above-mentioned prior art, it is the object of the present invention to present an apparatus for manufacturing pipe sections, the production of which can be controlled in greater detail and can even be varied during production in order to obtain a higher quality product. [Means for solving the problem]

[0004] This object may be achieved by an apparatus for producing an insulated pipe section, the apparatus comprising a rotatable longitudinal mandrel configured to receive uncured mineral wool and wind it around the mandrel to produce an insulated pipe section, a belt, preferably an endless belt, at least two longitudinal jaws engaging the belt and configured to move between an open position and a closed position in which the jaws are configured to substantially surround the mandrel by the belt, and a mandrel control element configured to actively control the lateral movement of the mandrel.

[0005] To begin the winding process, a web of uncured mineral wool is placed between the mandrel and the belt, and as the belt and mandrel are driven, the web is wound around the mandrel into a pipe section.

[0006] In one embodiment, the two jaws define a winding basket in the closed position for guiding the belt substantially 360° around the pipe section being wound around the mandrel, the winding basket being maintained in the closed position during the winding process.

[0007] Thus, by actively controlling the lateral movement of the mandrel inside the winding basket, a more homogenous density distribution and fiber structure can be obtained than with prior art processes.

[0008] Each of the two longitudinal jaws extends in a longitudinal direction transverse to the belt, the belt preferably having a width at least as large as the length of the pipe section to be produced.

[0009] The mandrel control elements are configured to actively control lateral movement of the mandrel by acting on both ends of the mandrel, the lateral movement being transverse to a longitudinal direction of the mandrel, and the mandrel control elements are configured to actively control lateral movement of the mandrel during production of the insulated pipe section between a first position substantially at an inner surface of the jaws and a second position further spaced from the jaws within the winding basket.

[0010] The apparatus may include a motor configured to drive the belt.

[0011] The mineral wool may be any insulating material having a fibrous structure, such as, for example, stone wool or glass wool.

[0012] At the start of production of the insulated pipe section, the jaws are preferably in a closed position with the mandrel close to the inner surface of the jaws, and as the mineral wool is wound around the mandrel, the insulated pipe section is given a substantially circular cross-section. As more and more mineral wool is wound around the mandrel, the mandrel is moved laterally away from the inner surface of the jaws, allowing the pipe section to become thicker while still maintaining a substantially circular cross-section.

[0013] The mandrel control element controls the lateral position of the mandrel inside the jaws during the manufacturing process, meaning that the density of the wound mineral wool can be varied as a function of radius. Mineral wool has a density for optimal insulating properties. The same mineral wool will not insulate as well as mineral wool with optimal density in a denser or less dense state. However, a trade-off approach is often applied that balances cost and insulating value. By actively controlling the lateral movement of the mandrel, the density of the mineral wool can be precisely controlled and even provide a controlled density variation throughout the thickness of the pipe section. By controlling the lateral position of the mandrel during winding, pipe sections with varying densities can be easily made and different types of pipe sections can be used for different situations.

[0014] If the inside of the pipe section is made with low density, it can be applied to pipes with different diameters and the pipes can be placed in the cavity of the pipe section, because the insulation around the cavity for the pipe has such a low density that a pipe with a larger diameter will compress the insulation and make the necessary space. If the inside of the pipe section is made with high density, it can be perfectly fitted to a pipe with an outer diameter identical to the inner diameter of the pipe section.

[0015] In one embodiment, the belt may form a loop, with the mandrel being outside the loop.

[0016] The mandrel being outside the loop means that the mandrel with the produced pipe section can easily be removed from the production position between the jaws and a new mandrel can be inserted between the jaws.

[0017] In one embodiment, the mandrel control elements may be configured to rotate the mandrel by acting on both ends of the mandrel.

[0018] The mandrel may have a cylindrical surface with a base at each end. The mandrel typically has a circular cross-section, although other cross-sections are possible, such as a square, rectangular or other polygonal cross-section.

[0019] The mandrel may be a hollow cylinder, at least at the ends of the mandrel, and two other cylinders, preferably two tapered cylinders, may be inserted into the hollow cylinder to control the lateral position of the mandrel during production of the pipe section and to rotate the mandrel.

[0020] The fibrous insulation winding section of the mandrel is the section where the fibrous insulation is wound onto the mandrel. Of course, shorter pipe sections can also be produced, in which case a larger part of the mandrel is outside the fibrous insulation winding section.

[0021] In one embodiment, the belt engages the mandrel or the uncured mineral wool wound around the mandrel. By engaging, the mandrel is in direct contact, so that compression of the wound uncured mineral wool can be controlled by tension of the belt acting thereon. As discussed and illustrated herein, the belt engages at least the mandrel or the uncured mineral wool wound around the mandrel when the jaws are in a closed position.

[0022] In another embodiment, the mandrel is rotated by the belt by acting on the wound fibrous insulation. With this embodiment, the mandrel does not have to be rotated only through the wound fibrous insulation, but also by a mandrel control element acting directly on the mandrel. The advantage of this is that the mandrel can have a rotation speed such that the outer layer of the manufactured pipe section has the same surface speed as the belt, so that the wound fibrous insulation is not unwound or wound more than intended, which could make the pipe section denser than intended. Of course, the mandrel can also be rotated at a rotation speed such that the outer layer of the manufactured pipe section has a higher or lower surface speed than the belt, so that the wound fibrous insulation is intentionally tighter or looser.

[0023] In one embodiment, the apparatus may include a belt control element configured to control a moving speed of the belt, wherein during manufacturing of the pipe section, the belt control element is configured to keep the moving speed constant and the mandrel control element is configured to reduce the rotation speed.

[0024] If the rotational speed of the mandrel is kept constant, as the diameter of the pipe section increases, the speed at the outer layer of the pipe section increases, so that either the belt speed must increase or the mandrel rotational speed must decrease with increasing pipe section diameter to be able to keep the surface speed of the outer layer of the manufactured pipe section equal to the moving speed of the belt.

[0025] It is preferred to decrease the rotational speed of the mandrel as the diameter of the pipe section increases, because controlling the speed of the mandrel is technically less complicated than controlling the speed of the belt, since if the belt speed is increased, the feed rate of the uncured mineral wool must also increase, which is preferably constant.

[0026] In one embodiment, the at least two longitudinal jaws may be movable relative to one another to release the mandrel in the open position.

[0027] When winding of the uncured mineral wool around the mandrel to form the pipe section is completed, the jaws are spread apart so that the mandrel with the pipe section can be removed from its position between the jaws. Preferably, the jaws can be spread apart so that the mandrel can be removed by a mandrel remover at the two ends of the mandrel, which is usually elongated. Before the jaws close again, a mandrel feeder can deliver a new mandrel between the jaws and wind mineral wool onto the new mandrel.

[0028] In one embodiment, the at least two longitudinal jaws may have two longitudinal edges of each, the at least two longitudinal jaws being rotatable about an axis at two adjacent longitudinal edges.

[0029] The two longitudinal jaws are rotatable around two axes at adjacent longitudinal edges so that, in the open position, the two jaws can be spread wide enough to easily remove even manufactured pipe sections with large diameters from the device, in particular from the winding basket.

[0030] In one embodiment, the apparatus may include a tensioner for tensioning the belt.

[0031] The tensioner keeps the belt under tension so that it can be rotated by the belt control element.

[0032] In one embodiment, the apparatus may include a tension sensor configured to sense tension in the belt.

[0033] By adjusting the tensioner, the belt can be adjusted to have the correct tension, i.e., the belt is not too loose so that the belt control elements cannot move / rotate it, and is not too stretched so that the belt control elements have to use too much force to move / rotate it and / or the pipe sections are clamped together and become too tight. As the diameter of the pipe sections increases, the tensioner must be adjusted during the overall manufacturing process.

[0034] Controlling the tension so that it is constant means that the pipe section can be made homogeneous. The tension in the belt increases as the diameter of the pipe section increases, unless the tensioner is adjusted to increase the diameter of the belt around the mandrel.

[0035] In one embodiment, the tensioner can be configured to receive a tension signal related to the tension from a tension sensor to control the tension.

[0036] As mentioned above, as the diameter of the pipe section increases, the tension in the belt increases unless the tensioner is adjusted to increase the diameter of the belt around the mandrel. To accommodate pipe sections with homogenous insulation, the tension in the belt must remain constant. A tension sensor can measure the tension in the belt and control the tensioner accordingly.

[0037] In one embodiment, the tensioner may be configured to adapt the tension of the belt based on the received tension signal and a pre-determined tension. In this way, a desired tension may be maintained during the entire manufacturing process. For example, by having a lower tension at the beginning of the manufacturing process than at the end, the inner portion of the pipe section may be made to have a lower density, and the same pipe section may fit pipes within a certain diameter range. It is also possible to have a higher tension at the beginning of the manufacturing process, so that the inner portion of the pipe section has a higher density than the rest of the pipe section.

[0038] In one embodiment, the mandrel control element may be configured to emit a position signal and the tensioner is configured to receive the position signal.

[0039] This provides a tensioner that takes into account the position of the mandrel, and in some embodiments also the diameter of the mandrel, when controlling the tension of the belt. Combining the position of the tensioner, the position of the mandrel, and the known length of the endless belt, the size of the pipe section currently wound on the mandrel can also be determined. Furthermore, coupled with information about the amount and type of uncured mineral wool used in the process, the density / compression of the pipe section can also be estimated. This can be derived, for example, continuously throughout the process and the tension adjusted accordingly, for example as previously described herein.

[0040] At the start of production of a pipe section, the belt is draped over the mandrel, which is positioned near the winding basket opening, and as the diameter of the pipe section increases, the mandrel is moved away from the winding basket opening in a controlled manner to provide space for the increasing pipe section.

[0041] In one embodiment, each jaw may include two jaw end sections between which a roller is rotatably held in position to guide the belt.

[0042] In one embodiment, the jaws in the closed position may form a substantially cylindrical shape.

[0043] In one embodiment, the apparatus may include two flange plates located at each base of the mandrel.

[0044] The flange plates prevent the wool from being squeezed out to the side during the rolling process. They also provide the manufactured pipe sections with straight and perpendicular end sections, so that when installed around the pipe, the ends of the two pipe sections are positioned against each other in a tight insulating manner. However, preferably, the ends of the hardened pipe sections are mechanically cut to ensure perfectly planar end faces. During the rolling process, the flange plates contact the base of the pipe section and can be rotated at the same speed as the mandrel, or are in a freewheeling condition so that the flange plates rotate when friction from the rotating pipe section tries to rotate them.

[0045] The invention also relates to a method for manufacturing an insulating pipe section, the method comprising the steps of providing a rotatable longitudinal mandrel, providing a belt, preferably an endless belt, providing at least two longitudinal jaws engaging with the belt and substantially surrounding the mandrel with the belt, winding uncured mineral wool onto the mandrel to produce a pipe section between the mandrel and the belt, and actively controlling the mandrel in the lateral direction by acting on both ends of the mandrel.

[0046] In one embodiment, the mandrel may be rotated by mandrel control elements acting on both ends of the mandrel.

[0047] In one embodiment, the mandrel may be rotated at a mandrel rotation speed that decreases as more fibrous insulation is wound onto the mandrel.

[0048] The invention is explained in more detail below with reference to the accompanying drawings. [Brief description of the drawings]

[0049] [Figure 1a] FIG. 1 is a schematic diagram of the device with the jaws open. [Figure 1b] FIG. 1 is a schematic diagram of the apparatus with an empty mandrel surrounded by the jaws. [Figure 1c] FIG. 1 is a schematic diagram of an apparatus with a semi-finished pipe section. [Figure 1d] FIG. 1 is a schematic diagram of the apparatus with the pipe section in the completed state. [Diagram 2] FIG. 2 is a schematic diagram of a jaw. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0050] FIG. 1a discloses an apparatus 2 for manufacturing pipe sections (not shown), the apparatus comprising two jaws 4, 6 in an open position. A mandrel 8 is engaged with and held by a linear motion mandrel drive 10. The apparatus also comprises a belt 12 looped around a first roller 13, a second roller 14, a third roller 15 and a fourth roller 16, a belt control element (not shown) driving the belt by one or more of the rollers 13, 14, 15, 16. The rollers may have at least the same width as the belt to support the entire width of the belt. The first roller 13 may be a tensioner 13 in the form of a so-called "dancer" movable vertically, preferably in a manner controlled by a position-controlled motor. When the jaws 4, 6 are in the open position, the tensioner has a lower position to keep the belt stretched. Each of the jaws 4, 6 comprises two jaw end sections 18 connected by a longitudinal roller 20 (only one of which is shown in Figs. 1a-1d). The roller 20 guides the belt around the jaws. The jaws 4, 6 are pivotable about pivot axes 22, 24, respectively, so that the jaws can be opened and closed. In the open position of the jaws 4, 6 shown, the mandrel with the manufactured pipe section (not shown) can be removed, for example by a robot (not shown), and a new empty mandrel can be received, for example by a robot. One of the rollers 13, 14, 15, 16 can be suspended by a spring (not shown) to provide elasticity to the otherwise inelastic belt 12. The spring-suspended roller can have a first force meter (not shown) to measure the force from the belt acting on the spring-suspended roller.

[0051] In FIG. 1a, the mandrel 8 has just been engaged with the mandrel drive 10 and the mandrel is empty.

[0052] Figure 1b discloses a device 2 with two jaws 4, 6 in the closed position forming a winding basket 25, which surrounds a mandrel 8. When the jaws 4, 6 are closed, the mandrel is surrounded by a belt 12. Since in the closed position the mandrel is surrounded by the belt, the length of the belt between the second roller 14 and the third roller 15 around the jaws is longer than when the jaws are open as in Figure 1a. For this reason the first roller 13, i.e. the tensioner 13, has been moved upwards in Figure 1b compared to Figure 1a.

[0053] A web of uncured mineral wool 26, such as stone wool or glass wool, is fed from the right hand side of Figure 1b. The uncured mineral wool may be received directly from an uncured mineral wool production line or a manufactured web of uncured mineral wool may be transported to a position on the right hand side of the apparatus in Figure 1b and fed into the apparatus. The uncured mineral wool is received between the jaws via a winding basket opening 28 and is wound around the mandrel between the mandrel and the belt as the mandrel and belt are rotated. The mandrel and belt are preferably driven in a controlled manner.

[0054] In Figure 1c, uncured mineral wool 26 is in the process of being wound around mandrel 8 to form pipe section 30. Due to the thickness of the pipe section, a longer section of the belt is inside the jaws 4, 6 and winding basket 25, and the tensioner 13 has moved further upwards from the position illustrated in Figure 1b when the mandrel is empty. As more and more uncured mineral wool is wound onto the mandrel to make up the pipe section, the tensioner 13 gradually moves further upwards.

[0055] As can be seen in Figures 1b-1c, the belt 12 engages the mandrel 8 or the uncured mineral wool 26 wound around the mandrel. Thus, by adjusting the belt tension and / or the belt speed, as discussed herein, the belt can be used to control the compression of the uncured mineral wool.

[0056] As the diameter of the pipe section 30 increases, the mandrel 8 is moved in a controlled manner by the linear motion mandrel drive 10 leftwards towards the centre of the winding basket 25 to ensure that the outer diameter of the pipe section remains close to the winding basket opening 28 until the mandrel manufacturing process is finally completed as shown in FIG. 1d.

[0057] The feed speed of the web of uncured mineral wool 26 and the speed of the belt 12 are preferably kept constant so that the web of uncured mineral wool is subjected to the same forces and stresses during the entire manufacturing process to achieve a homogenous structure of the pipe section. This also means that the rotational speed of the mandrel must be reduced as the diameter, and therefore the circumference, of the pipe section increases during the manufacturing process. Similarly, the linear motion mandrel drive 10 moves the mandrel more and more slowly as the diameter of the pipe section increases during the manufacturing process.

[0058] The tensioner 13 may be spring loaded, so that it can easily adapt when the diameter of the pipe section increases, and provide good tension regardless of the diameter of the pipe section, or the tensioner may keep the belt stretched by the gravity of the tensioner. The tensioner may include a tension control element to control the tension of the belt by controlling the vertical movement of the tensioner. The apparatus may include software programmed to actively control the tension control element to move the tensioner so that the belt has the desired tension during the overall manufacturing process. This gives the correct density to the manufactured pipe section to achieve the desired insulating and physical properties of the pipe section. The tensioner may have a force meter to measure the tension of the belt. The tensioner may receive the measured force from the force meter and adapt the tension to the predetermined tension of the belt.

[0059] The tensioner may have other forms than those illustrated in Fig. 1a-1d. It may comprise two rollers, connected at their ends by two bars, which are suspended in the device by a pivotable axis, around which the two bars and the two rollers can be pivoted. The belt is wound around one of the two rollers on the right side and the other of the two rollers on the left side, and the belt is stretched by pivoting the two rollers in one direction and loosened by pivoting the two rollers in the opposite direction. The two rollers may be rotated in a controlled manner to ensure the desired tension of the belt at all times during the production of the pipe section. Only if the two rollers are asymmetrically located on the pivotable axis, the two rollers may be spring-loaded or moved by gravity.

[0060] When the pipe section 30 has finally been produced as illustrated in Figure 1d, the jaws 4, 6 are opened to the position illustrated in Figure 1a and the mandrel 8 with the finished pipe section is removed. The finished pipe section is transferred to a curing device where the uncured mineral wool is cured, usually by heat. A new mandrel is placed in the apparatus 2 so that a new pipe section can be wound around it, and the production process returns to the stage illustrated in Figure 1a. When the jaws are opened, the tensioner is moved to the lower position shown in Figure 1a in order to keep the belt 12 under tension.

[0061] The jaws close around a new mandrel and a new web of uncured mineral wool is fed onto the mandrel through the winding basket opening 28 and production of a new pipe section can begin, as illustrated in Figure 1b.

[0062] Figure 2 illustrates the jaws 4, 6 diagrammatically in a perspective view illustrating the jaw end section 18. Longitudinal rollers 20 are held in place by the jaw end section to guide a belt (not shown). The jaws 4, 6 are pivotable about axes 32, 34 which coincide with axes 22, 24 (Figure 1a).

Claims

1. 1. An apparatus for producing insulated pipe sections, comprising: a rotatable longitudinal mandrel configured to receive and wind uncured mineral wool thereabout to produce an insulated pipe section; a belt, preferably an endless belt; at least two longitudinal jaws for engaging the belt, the jaws configured to move between an open position and a closed position in which the jaws are configured to substantially surround the mandrel with the belt; and a mandrel control element configured to actively control lateral movement of the mandrel.

2. 2. The apparatus of claim 1, wherein the two jaws, in the closed position, define a winding basket for guiding the belt substantially 360° around the pipe section being wound around the mandrel, the winding basket being configured to remain in a closed state during the winding process.

3. The apparatus of claim 1 , wherein the belt engages the mandrel or the wound uncured mineral wool around the mandrel when the two jaws are in the closed position.

4. The apparatus of claim 1 , wherein the belt forms a loop and the mandrel is outside the loop.

5. The apparatus of claim 1 , wherein the mandrel control elements are configured to rotate the mandrel and / or move the mandrel laterally by acting on opposite ends of the mandrel.

6. a belt control element configured to control a speed of movement of the belt; During the manufacture of said pipe sections, the belt control element is configured to keep the speed of travel constant; The apparatus of claim 1 , wherein the mandrel control element is configured to reduce a rotational speed of the mandrel.

7. The apparatus of claim 1 , wherein the at least two longitudinal jaws are movable relative to one another to release the mandrel in an open position.

8. The device of claim 1 , wherein the at least two longitudinal jaws each have two longitudinal edges, and the two longitudinal jaws are rotatable about an axis at two adjacent longitudinal edges.

9. The apparatus of claim 1 comprising a tensioner for tensioning the belt.

10. The apparatus of claim 9 , wherein the mandrel control element is configured to emit a position signal and the tensioner is configured to receive the position signal.

11. The apparatus of claim 1 , wherein the apparatus comprises a tension sensor configured to sense tension in the belt.

12. 12. The apparatus of claim 9 or 10 and claim 11, wherein the tensioner is configured to receive a tension signal relating to the tension from the tension sensor to control the tension.

13. 13. The apparatus of claim 12, wherein the tensioner is configured to adjust the tension of the belt based on the received tension signal and a predetermined tension.

14. 10. The apparatus of claim 1, comprising two flange plates located at each base of the mandrel.

15. 1. A method for manufacturing an insulated pipe section, comprising the steps of: Providing a rotatable longitudinal mandrel; Providing a belt, preferably an endless belt; providing at least two longitudinal jaws for engaging said belt such that said mandrel is substantially surrounded by said belt; winding uncured mineral wool onto the mandrel to produce an insulated pipe section between the mandrel and the belt; and actively controlling lateral movement of the mandrel.

16. The method of claim 15 , wherein the mandrel is rotated by mandrel control elements acting on opposite ends of the mandrel.

17. 16. The method of claim 15, wherein the mandrel is rotated at a mandrel rotation speed that decreases as more uncured mineral wool is wound onto the mandrel.

18. The method of claim 15 , wherein the uncured mineral wool is cured in a curing device.

19. The method of claim 15 , wherein the lateral movement of the mandrel is effected by actively controlling both ends of the mandrel.

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