OVEN, ADAPTED TO HEAT PREFORM BUILDING MATERIAL ARRANGED ON A TRANSPORTABLE, PLATE-LIKE MOLD CARRIER FOR PRODUCING PREFORM BUILDING ELEMENTS USED FOR BUILDING A ROTOR BLADE OF A WIND TURBINE

Abstract

An oven, adapted to heat preform building material arranged on a transportable, plate-like mold carrier for producing preform building elements used for building a rotor blade of a wind turbine is provided, with a housing adapted to receive several covered mold carriers and having a closable front and a closable rear opening for loading and unloading the mold carriers, wherein the housing includes several receiving means arranged in different levels with each receiving means being adapted to receive at least one mold carrier, and with several heating means assigned to the several intermediate spaces between vertically adjacent mold carriers and the spaces below and/or above the top and bottom mold carrier and adapted to heat the preform building material.

Claims

1. An oven, configured to heat preform building material arranged on a transportable, plate-like mold carrier for producing preform building elements used for building a rotor blade of a wind turbine, comprising: a housing configured to receive several covered mold carriers and having a closable front and a closable rear opening for loading and unloading the mold carriers, wherein the housing comprises several receiving means arranged in different levels with each receiving means being configured to receive at least one mold carrier; and several heating means assigned to several intermediate spaces between vertically adjacent mold carriers and spaces below and/or above a top and bottom mold carrier and configured to heat the preform building material.

2. The oven according to claim 1, wherein a heating means is a hot air heating means and comprises several heating air inlets and several heating air outlets for providing a heating air flow through the respective space.

3. The oven according to claim 2, wherein the heating means comprises several heating air inlets arranged at one side wall of the housing and several heating air outlets arranged at an opposite side wall of the housing allowing a transvers air flow, with the inlets and outlets being arranged in a row and assigned to the respective space.

4. The oven according to claim 3, wherein each inlet is arranged opposite to an outlet.

5. The oven according to claim 2, wherein the heating means comprises several heating air inlets arranged at one end of the housing and several heating air outlets arranged at the other end of the housing allowing a longitudinal air flow, with the inlets and the outlets being assigned to the respective space.

6. The oven according to claim 2, wherein the heating means comprises several first heating air inlets arranged at one side wall of the housing and several first heating air outlets arranged at the opposite side wall of the housing allowing a transvers air flow, wherein the first inlets and first outlets are arranged at both ends of the housing realizing two first heating zones, and wherein the heating means comprises several second heating air inlets arranged closer to one end of the housing and several second heating air outlets arranged closer to the other end of the housing allowing a longitudinal air flow and realizing a second intermediate heating zone, with the first and second inlets and outlets being assigned to the respective space.

7. The oven according to claim 6, wherein the first and second heating zones are separated by respective separation means.

8. The oven according to claim 7, wherein the separation means are air curtains or flexible mechanical curtains assigned to each space and are removable.

9. The oven according to claim 1, wherein a heating means comprises several heating elements arranged in the space.

10. The oven according to claim 9, wherein a heating element is a radiation heating element or a resistance heating element.

11. The oven according to claim 10, wherein the radiation heating element is an infrared radiation or ultraviolet radiation heating element.

12. The oven according to claim 9, wherein the heating means comprises both radiation heating elements and resistance heating elements.

13. The oven according to claim 2, wherein the heating means comprises both a hot air heating means and heating elements.

14. The oven according to claim 1, wherein the closeable front opening and the closable rear opening is closable by a door.

15. The oven according to claim 1, wherein means for realizing respective air curtains at the closable front opening and the closable rear opening or flexible mechanical curtains at the closable front opening and the closable rear opening are provided.

16. The oven according to claim 1, wherein the receiving means comprise guiding rails, arranged at the housing side walls.

17. The oven according to claim 16, wherein the guiding rails comprise roller elements or sliding elements on which the respective mold carrier is guided.

18. The oven according to claim 1, wherein one or more air flow sensors and/or temperature sensors are provided, which communicate with a heating control, which controls the heating means based on information provided by the sensors.

Description

BRIEF DESCRIPTION

[0029] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0030] FIG. 1 is a principle illustration of a manufacturing arrangement of a preform comprising a modular mold, an oven and a cooling means;

[0031] FIG. 2 is a perspective and partially cut open illustration of the oven;

[0032] FIG. 3 is a principle illustration of an oven of a first embodiment with hot air heating means;

[0033] FIG. 4 is a principle illustration of an oven of a second embodiment with heating elements in form of resistance heating elements;

[0034] FIG. 5 is a principle illustration of an oven of a third embodiment with heating means comprising hot air heating means and resistance heating elements;

[0035] FIG. 6 is a principle illustration of an oven of a fourth embodiment with heating means comprising radiation heating elements and resistance heating elements;

[0036] FIG. 7 is a principle top view of the oven with a heating means arrangement of a first embodiment;

[0037] FIG. 8 is a principle top view of the oven with a heating means arrangement of a second embodiment;

[0038] FIG. 9 is a perspective partial view of the oven according to FIG. 4 showing a separation means;

[0039] FIG. 10 is a principle top view of the oven with a heating means arrangement of a third embodiment; and

[0040] FIG. 11 is a perspective and partial cut open illustration of an oven of a further embodiment.

DETAILED DESCRIPTION

[0041] FIG. 1 shows a manufacturing arrangement 1 for producing preforms for a wind turbine blade. It shows a mold 2 comprising a mold base 3 and a removable mold carrier 4, which is already partially removed from the mold base 3. Although only one mold 2 is shown, the manufacturing arrangement 1 comprises several of these molds 2 arranged side by side, all of which are modular molds comprising a mold base 3 and a removable mold carrier 4.

[0042] Arranged on the mold carrier 4 is preform building material 5 which is covered by a vacuum sealing foil 6. The building material 5 comprises fiber material like mats made of glass or carbon fibers, optionally at least one or several core elements for example made of wood like balsa wood or of a polymer foam or the like, and a binding agent usually in powder or granular form. The binding agent is provided only locally so that the building material respectively the mats and if provided the core elements are only locally fixed, when the binding agent has been molten and cooled again, as will be explained below. The building material 5 is vacuum-fixated on the mold carrier 4, as the vacuum sealing foil 6 seals a space between the foil 6 and the mold carrier 4, which is evacuated by a respective evacuation pump. The vacuum is maintained so that the mold carrier 4 can be transported.

[0043] The mold carrier 4 is, as shown by the arrow P1, partially already removed from the mold base 3 and loaded onto a transport means 7, here in form of a rack, where already several other mold carriers 4 with the respective building material 5 and vacuum sealing foils 6 are arranged. The transport means 7 moves on rails 8 along the row of molds 2 and receives the respective covered mold carriers 4. This rail guided movement is shown by the arrow P2.

[0044] The transport means 7 moves to an unloading position in which it is arranged adjacent to an oven 9, which has an opening 10, into which all covered mold carriers 4 can be loaded from the transport means 7. This unloading is shown by the arrow P3.

[0045] In the oven, the preform building material 5 is heated so that the binding agent melts and wets respectively embeds the other building material like the fiber mats and core elements into a respective binder matrix. After this temperature treatment, the heated mold carriers 4 are unloaded from the oven 9 through a rear opening 11 as shown in FIG. 2 and are moved into a cooling means 12, where it is cooled down to room temperature. The cooling means 12, also box-like like the oven 9, comprises a respective front loading opening and a rear unload opening. The mold carrier transfer from the oven 9 into the cooling means 12 is shown by the arrow P4.

[0046] After the preform building material 5, which is fixed by the binding agent, is cooled, it is removed from the cooling means 12 as shown by the arrow P5. The mold carriers 4 with the respective finished preform elements may then either be stored until the respective preform is needed or they may be directly transported to a construction site where the blade is built. It is also possible to remove the finished preform element from the mold carrier 4 after the cooling stage and to store the fixed and form-stable preforms either in a storage or to transport only the preforms to the construction site.

[0047] FIG. 2 shows a perspective principle illustration of the in part cut-open oven 9. The oven 9 comprises a housing 15 having a bottom 16, a top wall 17 and two side walls 18, 19. The housing 15 is open at both ends having a front opening 10 and a rear opening 11. Both openings 10, 11 are closable via roller doors 13, 14, which are open in FIG. 2.

[0048] At the side walls 18, 19 respective receiving means 20 in form of guiding rails 21 are provided which extend almost over the entire length of the side walls 18, 19. The length of the housing 15 corresponds to the length of the mold carriers 4, which are received on the respective receiving means 20. The receiving means 20 respectively the guide rails 21 are arranged in different heights so that the separate mold carriers 4 are arrangeable one above the other, as shown in FIG. 2. The guiding rails 21 may be provided with roller elements 22, while also sliding elements may be provided. Both are easing the loading and unloading process, during which each mold carrier 4 is placed on a pair of guide rails 21 and pushed into the oven 2 respectively pulled out of the oven 2, as shown in FIG. 2. The upper mold carrier 4 is pushed into the oven 2, while the lowest mold carrier 4 is pulled out of the oven 2. This loading and unloading process may be performed manually or automatically.

[0049] As already mentioned, the guide rails 21 are arranged at the side walls 18, 19. When the mold carriers 4 are loaded into the oven 2, they separate the whole oven chamber into respective smaller spaces 23, as shown in the FIGS. 3-6. In these examples, four plate- or trough-like mold carriers 4 are arranged on the respective receiving means 20 respectively guide rails 21. They extend from one side wall 18 to the other side wall 19. As mentioned, the length of the oven chamber corresponds to the length of the mold carriers 4, so that each mold carrier 4 separates a respective space 23.

[0050] To each space 23 a heating means 24 is assigned, which heating means 24 is, according to the embodiment of FIG. 3, realized as a hot air heating means, which comprises several hot air inlets 25, here arranged at the side wall 19, and several hot air outlets 26 arranged at the side wall 18. To each separate space 23 a respective number of inlets 25 and outlets 26 is assigned. Several inlets 25 are arranged side by side along the length of the side wall 19, the same is true for the outlets 26 at the side wall 18. The inlets 25 arranged to each space 23 are arranged in a horizontal row, the same is true for the respective outlets 26. The inlets 25 are directly opposite to the outlets 26 in each level respectively space 23.

[0051] Via the inlets 25 hot air, which has a temperature exactly corresponding to the desired temperature in the oven 2, is blown into the respective space 23, as shown by the arrows P6. It exits the chamber respectively space 23 via the respective outlets 26. Both, the inlets 25 and outlets 26 are connected to respective pipes 27, 28 as shown in FIG. 3, which pipes 27, 28 are coupled to an air temperature device which heats the air before it is blown into the chamber. A respective control is provided which controls the temperature and airflow. To control this, airflow sensors 29 and/or temperature sensors 30 may be arranged in the oven chamber respectively in each space 23. Although FIG. 3 shows only one airflow sensor 29 and one temperature sensor 30, several of these sensors may be distributed in each separate space 23 in order to measure each space specific airflow and temperature in order to specifically control the airflow respectively the heating via the overall control device. This may be done for example by controlling respective valves which are connected for example to the respective inlets 25 in order to vary the airflow respectively amount of air, or by controlling the air temperature etc.

[0052] FIG. 4 shows another embodiment of an oven 9, in which again four mold carriers 4 are loaded. They again devide the oven chamber into five separate spaces 23. Each chamber 23 is assigned with a number of heating elements 31. Each heating element is for example a resistance heating element 32, which is connected via respective cables 33 to a not shown power source so that they can be heated by controlling a respective current. Each resistance heating element 32 is for example designed like a longitudinal rod or the like, which extends in a transverse direction, so that in each space a certain number of these resistance heating elements 32 are arranged in a row and parallel to each other.

[0053] As shown, the resistance heating elements emit the heat as well to the upper surface of each mold carrier 4, where the building material is arranged, as to the bottom side of the respective mold carrier 4, so that also this type of heating element 31 allows a very even tempering of the mold carriers 4 respectively the building material in order to melt the binding agent.

[0054] Again, several temperature sensors 30 are distributed within the spaces 23 allowing to monitor the temperature respectively temperature distribution within each chamber. These measured values are provided to the control device controlling the heating elements 31, which may be individually controlled so that it is possible to immediately react if any inconsistancy regarding the temprature distribution respectively the temperature level is recognized.

[0055] Alternatively, this kind of heating elements 31 could also be realized as radiation elements, i.e. radiation lamps, which emit an ultraviolet or infrared radiation. These radiation elements respectively lamps may be of cylindrical shape so that they emit the radiation in all directions. Also, these radiation elements are connected to a power source and may be individually controlled by a control device, again based on temperature sensor information. These radiation elements respectively radiation lamps also allow to evenly temper the building material for melting the binding agent.

[0056] Another embodiment of an oven 9 is shown in FIG. 5. Again, four mold carriers 4 with respective building material 5 are arranged on the respective receiving means 20 respectively the guiding rails 21, just like in the other embodiments. The mold carriers 4 divide the chamber volume into five separate spaces 23.

[0057] In this embodiment, the heating means comprises hot air heating means and heating elements. As shown, to the spaces 23, which are above the upper side of each mold carrier 4 respectively the building material, hot air heating means comprising hot air inlets 24 and hot air outlets 25 are provided, wherein several inlets 24 and outlets 25 are arranged in a row and are assigned to each respective space 23. The inlets 24 and outlets 25 again may be arranged opposite to each other in the respective side walls 18, 19.

[0058] In addition to the hot air heating means, also separate heating elements 31 are provided, which are again resistance heating elements 32, here in the form of heating wires which are connected to a respective power source which is controlled by a control device, just like the hot air heating means. The resistance heating elements 32 are arranged directly below each mold carrier 4 so that they almost directly heat the mold carrier 4 from below and thus heat the building material from below. The several resistance heating elements 32 assigned to a space 23 are arranged in parallel along the length of the space 23, but extend in a transverse direction.

[0059] Airflow sensors 29 are provided to sense the airflow in the respective chambers, as well as temperature sensors 30 in order to sense the temperature in the respective space 23.

[0060] In this embodiment, the control device may control two different types of heating means so that several degrees of freedom in controlling the heating of the respective space are provided. So, the control device may, depending on the respective sensor information, individually control either one or all of the hot air heating means or one or all of the heating elements in order to control an even temperature distribution.

[0061] FIG. 6 shows an example of an oven 9, again comprising four loaded mold carriers 4 with respective building material which devide the oven chamber into five spaces 23. Also, in this embodiment, different types of heating means are provided. In the spaces 23, above the upper side of the mold carriers 4 and therefore above the building material, separate heating elements 31, here in form of radiation elements 34, simplified shown as light bulbs, are provided which are connected via respective cables 35 to a power source and a control device. As shown, several of these separate radiation elements 34 respectively infrared or ultraviolet light bulbs are arranged in a row extending in a transverse direction. In each chamber 23, several of these rows are arranged. As shown, they radiate towards the upper side of each carrier 4 and therefore directly towards the building material.

[0062] Just like at the embodiment of FIG. 5, in addition also further heating elements 31 in form of radiation heating elements 34 are provided, again directly underneath each mold carrier 4. They are used to heat the mold carrier 4 and the building material from below. They extend in a transverse direction, while several of these separate resistance heating elements 32 are arranged in parallel, seen in the longitudinal chamber direction, in each space 23.

[0063] Again, the control device is adapted to control different types of heating elements, i.e. radiation heating elements 34 and resistance heating elements 32, which are separately controllable in order to control a constant and even temperature distribution.

[0064] FIG. 7 shows another embodiment of an oven 9, in which only hot air heating means 24 are provided. These hot air heating means 24 comprise several first hot air inlets 25, and several first hot air heating outlets 26, which are arranged at the respective side walls 18, 19, and which are assigned to each respective space 23, as the oven chamber again is divided into the respective spaces by the loaded mold carriers 4, which are not shown.

[0065] The first inlets 25 and outlets 26 are arranged at both ends of the housing 15, as clearly shown in FIG. 7. They realize two first heating zones 36 at both ends, directly connecting to the respective door 13, 14 opening and closing the respective openings 10, 11. In these first heating zones 36, a transverse hot airflow is provided, as shown by the arrows P6.

[0066] Furthermore, in the zone between the two first heating zones 36, a second intermediate heating zone 37 is realized with a longitudinal hot airflow, as shown by the arrows P7. To realize this, several second hot air inlets 38 are arranged opposite to each other and at both side walls 18, 19, adjacent to the right hand side first heating zone 36 in FIG. 7. Further, second hot air outlets 39 are provided closer to the left hand first heating zone 36 and opposite to each other at both side walls 18, 19. Again, to each space 23 a certain number of second inlets 38 and outlets 39 is assigned.

[0067] It is obvious that the hot air is blown into this intermediate space respectively second heating zone 37 at one end via the inlets 38, flows in a longitudinal direction and is drawn out of this second heating zone 37 via the outlets 39. So, in this embodiment, three separate heating zones 36, 37 are provided, two of them with a transverse hot airflow and one intermediate zone with a longitudinal airflow.

[0068] The zones 36 and 37 are separated by a separation means 40, here in form of respective air curtains 41, which are realized by respective nozzles 42, 43 arranged opposite to each other in the respective side walls 18, 19. They are like air barriers, so that the respective airflows in the neighboring heating zone 36, 37 do not interact or mix.

[0069] Again, an overall control device is provided which controls the hot air circuit respectively the air blower arranged in it and respective valves assigned to the respective inlets 25, 38 and/or outlets 26, 39 in order to individually or separately control the airflow in each heating zone 36, 37. Although not shown, several airflow sensors 29 and temperature sensors 30 may be distributed within the respective zone 36, 37 to monitor the airflow and temperature, based on which the control may be realized.

[0070] FIG. 8 shows an embodiment of an oven 9 which is identical to the setup of the oven shown in FIG. 7. Therefore, reference is made to the above explanation. The only difference is that the respective separation means 41 in this embodiment is realized by respective flexible mechanical curtains 44 which are, see FIG. 9, assigned to each space 23 extending above each mold carrier 4. Each curtain 44 comprises a certain number of separate lamellae 45, which are arranged on respective guide rails 46 so that they are removable respectively can be pushed to one side wall, if the respective space shall be opened, and can be moved to the separating curtain form when the space shall be closed. This can be done manually or automatically by a respective device.

[0071] Although not shown, it is possible to also arrange at the upper side of each rail 24 another curtain means which abuts the bottom side of each mold carrier 4 so that also here a complete closure is given. Another alternative is that the rails 46 are somehow bent corresponding to the bottom shape of each mold carrier 4.

[0072] FIG. 10 shows another more simplified embodiment of an oven 9 comprising a hot air heating means 24, where only a longitudinal airflow as shown by the arrows P7 is realized. In this embodiment, hot air inlets 25 are arranged on both side walls 18, 19 and opposite to each other at one housing end closer to the respective door 14, while the respective hot air outlets 26 are arranged closer to the other end of the housing next to the door 13. Again, the chamber volume is divided into the respective spaces 23 by the mold carriers 4, one of which is only shown in this top view. Therefore, the respective inlets 25 and outlets 26 are assigned to each separate space 23 and therefore are vertically arranged above each other corresponding to the vertically stacked spaces 23.

[0073] The airflow and/or temperature may be measured with respective airflow sensors 29 and temperature sensors 30, which are not shown in detail in this embodiment, just like at the embodiments of FIGS. 7 and 8. An overall control device is again adapted to control the respective hot air cycle respectively the air blower and respective valves etc., as already mentioned.

[0074] FIG. 11 shows a perspective, partially cut view of an oven 9 which corresponds to the version shown in FIG. 7. It shows the several mold carriers 4 dividing the chamber in the respective spaces 23. It also shows some hot air inlets 25 and some hot air outlets 26. As mentioned, they are connected to respective pipes of an air circuit. Further shown is a control device 47 like a computer or the like, controlling the respective hot air heating means by controlling respective valves or the like, which are connected by a respective wiring 48 to the control device 47.

[0075] Also shown are the air curtains 41 dividing the two first heating zones 36 from the intermediate second heating zone 37, as explained in regard to FIG. 7.

[0076] Further in this embodiment, both doors 13, 14 are shown partially opened. In order to avoid hot air flowing out of the oven when one or both doors 13, 14 are opened, respective further transverse air curtains 49 provided respectively realized by respective air curtain means like not further shown nozzles inn the side walls 18, 19, which are connected to respective pipes 50. These air curtains 49 seal both openings 10, 11, preventing any hot air flowing out of the oven. Also these air curtains 49 may be controlled via the control device 47. They may be permanently realized or only when one of the doors 13, 14 opens. They are then switched automatically. The loading and unloading process is possible even if the air curtains 49 are active, as it is easily possible to push or pull a mold carrier 4 through such an air curtain 49. The same is true for any of the air curtains 41.

[0077] These air curtains 49 are also shown in the embodiments of FIGS. 7 and 10.

[0078] In an alternative, as shown in FIG. 8, instead of these air curtains 49, also mechanical curtains 51 may be provided, which may be realized as lamellae curtains or the like which extend from the top to the bottom of the chamber. These mechanical curtains 51 may also be realized just like the curtains 44 so that they allow the loading and unloading of a mold carrier 4 even if the curtain 51 is closed.

[0079] Although the present invention has been disclosed in the form of embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0080] For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements.