Ordering device

Abstract

Application device for applying a coating medium to a moving surface (4), in particular a moving surface (4) in a paper machine, comprising an applicator (1) for applying the coating medium to the moving surface (4) and an enclosure (10) which, viewed in the direction of travel of the surface (4), is arranged at least partially behind the applicator (1), and wherein a collection chamber (5) is provided which is bounded by the moving surface (4), the enclosure (10) and optionally the applicator (1), characterized in that the enclosure (10) comprises a hinged element (2), wherein one end of the hinged element (2) is movably connected to a fixed wall (3) of the enclosure (10) or to the applicator (1), and wherein this movable connection is designed such that a second end of the hinged element (2) is arranged in an operating position in the immediate vicinity of the moving surface (4).and the folding element (2) can be folded outwards from this operating position with respect to the collection chamber (5).

Description

[0001] The invention relates to an application device for applying a coating medium to a moving surface, in particular a moving surface in a paper machine according to the preamble of claim 1.

[0002] Numerous coating processes are known for applying coating media to paper or cardboard webs. Film presses are frequently used, particularly for applying starch. In this process, a film of the coating medium is applied to a transfer roller and then transferred to the fiber web in a transfer nip. The coating medium is often applied in excess to the transfer roller and then metered to the desired application quantity using suitable doctor blade metering systems. Such doctor blade metering systems are described, for example, in German patent DE 102004029565 A1.

[0003] A well-known alternative to these doctor blade metering systems is spray application. For example, EP 3 219 849 discloses application systems in which the coating medium is sprayed onto the application rollers via a series of spray nozzles. The direct metering of the sprayed coating medium eliminates the need for contacting doctor blades. However, a disadvantage of the EP 3 219 849 method is that it requires a large number of spray nozzles, which are also prone to becoming dirty during operation.

[0004] As an improvement, the applicant presented an alternative spray application method in patent specification DE 10 2022 105 518 B4, which eliminates the need for numerous individual nozzles. In this method, a spray curtain is generated by a linear air jet spanning the width of the web, which strikes a film of coating medium.

[0005] In both conventional spray application with spray nozzles and alternative spray application methods, not all of the coating medium is transferred to the surface when the spray jet or curtain hits the moving web. A small portion escapes into the surrounding area as overspray. A chamber is typically provided to capture this overspray. This chamber is usually located behind the nozzles. To prevent overspray from escaping this chamber, the distance between the chamber and the moving surface must not be too great. This distance is typically a few millimeters.

[0006] These chambers, however, make accessing the application device more difficult. Firstly, the area around the spray nozzle(s) is obscured by the chamber housing. Furthermore, maintenance and cleaning, for example of the nozzles, requires disassembling the housing or, depending on the design, the entire application device. Finally, in the event of a malfunction, the proximity of the chamber to the moving surface also creates the risk of paper scraps or lumps becoming stuck to the application device.

[0007] The object of the invention is to overcome the problems of the prior art. In particular, it is an object of the invention to provide an application device that allows for simpler maintenance. Furthermore, it is an object of the invention to reduce damage in the event of a malfunction or to enable faster repair of such damage.

[0008] The problem is solved according to the invention by an embodiment according to the independent claim. Further advantageous embodiments of the present invention are found in the dependent claims.

[0009] A proposed application device for a moving surface comprises an applicator for applying a medium to the moving surface and an enclosure which, viewed in the direction of travel of the surface, is arranged at least partially behind the applicator, and wherein a collection space is provided which is bounded by the moving surface, the enclosure and, if applicable, the applicator.

[0010] According to the invention, the enclosure comprises a hinged element, wherein one end of the hinged element is movably connected to a fixed wall of the enclosure or to the applicator, and wherein this movable connection is designed such that a second end of the hinged element is arranged in an operating position in the immediate vicinity of the running surface, and the hinged element can be folded outwards from this operating position with respect to the collection space.

[0011] In the operating position, the collection chamber functions analogously to chambers known from the prior art.

[0012] Furthermore, including a folding element as part of the enclosure offers many additional advantages.

[0013] Firstly, the operator can actively fold away the hinged element. This provides a clear view of the interior of the collection chamber, allowing for visual inspection of the application nozzles. During operation or while the application device is starting up, the quality of the spray jets or spray curtain can also be visually checked.

[0014] Furthermore, the hinged element simplifies the maintenance and cleaning of the application device. Simple cleaning and minor maintenance work can be carried out without having to remove the application device completely or partially. For example, individual defective application nozzles can be replaced with the hinged element open.

[0015] Another major advantage of the folding element becomes apparent in the event of a malfunction. This advantage is particularly evident when the folding element is essentially oriented in the transverse direction of the machine and, in particular, extends across the entire transverse direction of the machine.

[0016] The hinged element and the fixed wall of the enclosure are usually made of sheet metal. Alternatively, versions made of other materials such as plastic composites, etc., are also conceivable.

[0017] The running surface can be formed either by the paper web or fiber web itself, or by a surface that is in contact with the paper web (e.g., a transfer roller, a belt, or a covering).

[0018] The terms medium and coating medium are used synonymously in the following. Suitable media that can be applied with application devices according to aspects of the invention are, in particular, starch solutions, barrier media, or pigment-containing coatings. However, water, cleaning agents, process chemicals, or similar substances can also be applied.

[0019] The applicator may in particular be a spray applicator suitable for applying the medium to the moving surface in the form of spray jets or a spray curtain.

[0020] In the event of a malfunction, such as a web break, paper can accumulate uncontrollably on the feed unit. For example, the transfer roller can become wrapped in paper, or clumps of paper can be transported into the collection chamber. In these situations, the technologically determined small distance between the housing and the running surface of feed units according to the prior art proves to be a disadvantage. When the roller becomes wrapped after a break, the available space between the surface and the housing is quickly filled with paper. If the system is not shut down quickly enough, the feed unit can be damaged, for example, by bending the wall of the housing. The hinged element proposed within the scope of the invention, on the other hand, can easily avoid such malfunctions.Because the hinged element is positioned downstream of the applicator (in the direction of surface movement), and because it can be folded outwards, it is simply pushed aside by paper or other debris carried into the collection chamber by the moving surface. This allows the paper to be transported back out of the collection chamber without damaging the housing or other parts of the application device.

[0021] In the case of wrapping a transmission roller, it is advantageous if the folding element is essentially aligned in the transverse direction of the machine and extends over the entire transverse direction of the machine.

[0022] The folding element is considered to be oriented "essentially" in the machine's transverse direction if it can still be folded away by obstructions carried along by the surface. Small deviations on the order of 5° or 10° from the machine's transverse direction are acceptable.

[0023] A further highly advantageous improvement is the inclusion of a retaining element that counteracts the folding element from folding away and is designed to hold the folding element in the operating position. Such a retaining element preferably comprises a retaining spring. To unfold the folding element, force must then be applied against the spring force of the retaining spring. A stop can be provided to hold the folding element in a predetermined operating position. This stop can be achieved, for example, through the shape of the folding element and the fixed wall of the enclosure. Alternatively, a separate stop element can be provided.

[0024] With such a retaining element, the folding element can be held in its operating position in a very defined manner, even if, for example, air currents act against the folding element.

[0025] Furthermore, a maintenance position can be provided, whereby the folding element can be folded from the operating position to the maintenance position. In particular, it can be advantageous if means are provided to fix the folding element in the maintenance position.

[0026] When the folding element is in the maintenance position, and especially when it is fixed in the maintenance position, cleaning work and minor maintenance work can be carried out particularly easily without having to remove the application device completely or partially.

[0027] In advantageous embodiments, a sensor can be provided that detects any movement of the folding element from its operating position during operation of the application device and generates a signal. This signal can then be further processed, for example, as a visual or audible warning, as a display in the control room, or in some other form. In this way, even minor malfunctions can be detected at an early stage.

[0028] Despite the described containment area, in applications where a very strong spray mist is generated, small particles of this mist may escape from the containment area due to the gap between the moving surface and the enclosure. To prevent uncontrolled escape into the environment in these cases, the enclosure can be fully or partially surrounded by a second enclosure.

[0029] In particular, it may be provided that the application device includes a second enclosure which is arranged behind the applicator in the direction of travel of the surface, and wherein the enclosure is wholly or partially enclosed by the second enclosure.

[0030] In this context, it will usually be advantageous if the second enclosure comprises a second hinged element, wherein one end of the second hinged element is movably connected to a fixed wall of the second enclosure or to the applicator, and wherein this movable connection is designed such that a second end of the second hinged element is arranged in an operating position in the immediate vicinity of the running surface, and the second hinged element can be folded outwards from this operating position.

[0031] The advantages of the folding element described above also apply to the second folding element.

[0032] It is possible that the second folding element is essentially oriented in the transverse direction of the machine, and in particular extends over the entire transverse direction of the machine.

[0033] A maintenance position can also be provided for the second folding element, whereby the second folding element can be folded from the operating position into the maintenance position. Means can also be provided to fix the second folding element in the maintenance position.

[0034] In particular, a retaining element may also be provided for the second folding element, which counteracts the folding of the second folding element and is designed to hold the second folding element in the operating position.

[0035] The invention is explained below with reference to the figures. The invention is not limited to the embodiments shown in the figures.

[0036] The figures show, in detail: Fig. 1a & 1b A dispensing device according to one aspect of the invention Fig. 2a & 2b Folding element for an application device according to aspects of the invention Fig. 3 A dispensing device according to a further aspect of the invention Fig. 4 A dispensing device according to a further aspect of the invention

[0037] Fig. Figure 1a shows an application device according to one aspect of the invention. Such an application device can be used, for example, for applying starch. Here, an applicator 1 is provided, which is designed as a spray applicator 1. The applicator generates a spray jet 6 (or a plurality of spray jets 6) or a spray curtain 6 from the coating medium, i.e., for example, from starch solution.

[0038] This coating medium is transferred to the running surface 4. In the case of the Fig. 1a The moving surface 4 is provided by the surface of a rotating transfer roller. From this surface 4, the medium can then be transferred in a treatment nip (not shown) onto a fibrous web. With this type of spray application, a spray mist 8 of coating medium is created, particularly behind the point of impact of the spray jet / curtain 6. This spray mist 8 is sometimes also referred to in the literature as "secondary spray". To prevent uncontrolled escape of this spray mist 8 into the environment, a collection chamber 5 is provided, which is bounded by the moving surface 4, the enclosure 10, and, if applicable, the applicator 1. In this example, the enclosure 10 is attached directly to the applicator 1. The enclosure 10 has a fixed wall 3 and a hinged element 2.The hinged element 2 is arranged such that one end of the hinged element is movably connected to a fixed wall 3 of the housing 10, and this movable connection is designed such that a second end of the hinged element 2 is arranged in an operating position in the immediate vicinity of the moving surface 4. This operating position is in . Fig. Figure 1a shows that the folding element 2 can be folded outwards with respect to the application area 5. It is particularly advantageous if the folding element 2 is oriented essentially in the transverse direction of the machine and extends over the entire transverse direction of the machine.

[0039] The order device from Fig. 1a also has a retaining element 7. In this case, this element is arranged at the location of the movable connection and may, for example, include a retaining spring. This retaining element counteracts the folding element 2 from folding away and holds it in its operating position.

[0040] Fig. 1b shows the application device Fig. 1a, however, here the hinged element 2 is folded into a maintenance position. It is advantageous to provide means to hold the hinged element 2 in this maintenance position. With the flap open in this way, maintenance and cleaning work on the applicator 1 can be carried out relatively easily, for example, without having to remove the application device or the housing.

[0041] The Fig. 2a and Fig. 2b shows the folding element 2 of the Fig. 1a and Fig. 1b again in detail. Fig. Figure 2a shows the folding element 2 in an operating position, and Fig. 2b in a maintenance position.

[0042] The hinged element 2 itself, as well as the fixed wall 3 of the housing 10, are made of sheet metal. The retaining element 7 has a retaining spring 7. This retaining spring 7 is connected to both the hinged element 2 and the fixed wall 3 and holds the hinged element 2 in the operating position. If the spring force of the retaining spring is overcome, the hinged element 2 can be moved out of the operating position. In the event of a malfunction, the hinged element 2 can thus move away from the obstruction. In the event of maintenance, the operator can move the hinged element 2 into a maintenance position.

[0043] In the Fig. 2a and Fig. In the embodiment shown in 2b, the movable connection between the folding element 2 and the fixed wall 3 is realized directly via the retaining element 7 in the form of the retaining spring 7.

[0044] Fig. 3 again shows a processing device. This, in extension to Fig. 1a a second enclosure 20, which, viewed in the direction of travel of the surface 4, is arranged behind the applicator 1. This second enclosure 20 surrounds the enclosure 10. The second enclosure 20 has a second hinged element 2a, which, analogous to the previous hinged element 2, is movably connected to a fixed wall of the second enclosure 20 and can be folded outwards. For the second hinged element 2a, in Fig. 3 a second retaining element 7a is also provided.

[0045] Fig. Figure 4 shows an exemplary application device in which the moving surface 4 is not provided by a transfer roller. The medium is applied in Fig.4 onto a circumferential belt 9, from which the medium can be transferred to the fiber web in a transfer nip. Alternatively, as indicated by the dotted line, the coating medium can also be applied directly to the fiber web, which in this example is supported by the circumferential belt 9. The belt 9 can, for example, be made of polyurethane and may also include a reinforcing structure. In this embodiment, the housing 10 is designed to completely enclose the applicator 1. In this embodiment, the applicator 1 does not define the collection space 5 for the spray mist 8, but is located entirely within it. Reference symbol list 1 applicator 2 folding elements 2a Second folding element 3 Fixed Wall 4 Running surface 5 Collection area 6 Spray jet / spray curtain 7 Retaining element 7a Second retaining element 8 spray mist Volume 9 10 Enclosure 20 Second enclosure QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102004029565 A1

[0002] EP 3 219 849

[0003] DE 10 2022 105 518 B4

[0004]

Claims

[1] Application device for applying a coating medium to a moving surface (4), in particular a moving surface (4) in a paper machine, comprising an applicator (1) for applying the coating medium to the moving surface (4) and an enclosure (10) which, viewed in the direction of travel of the surface (4), is arranged at least partially behind the applicator (1), and wherein a collection space (5) is provided which is bounded by the moving surface (4), the enclosure (10) and optionally the applicator (1), characterized by, that the enclosure (10) comprises a hinged element (2), wherein one end of the hinged element (2) is movably connected to a fixed wall (3) of the enclosure (10) or to the applicator (1), and wherein this movable connection is designed such that a second end of the hinged element (2) is arranged in an operating position in the immediate vicinity of the running surface (4), and the hinged element (2) can be folded outwards from this operating position with respect to the collection space (5). [2] Deployment device according to claim 1, characterized by , that the folding element (2) is essentially oriented in the transverse direction of the machine, and in particular extends over the entire transverse direction of the machine [3] Deployment device according to claim 1 or 2, characterized by, that a retaining element (7) is further provided which counteracts the folding element (2) and which is designed to keep the folding element (2) in the operating position. [4] Deployment device according to any one of the preceding claims, characterized by , that the applicator (1) is a spray applicator (1) suitable for applying the coating medium in the form of spray jets (6) or a spray curtain (6) to the running surface (4). [5] Deployment device according to any one of the preceding claims, characterized by , that the running surface (4) is provided by the surface of a transfer roller, a belt or a covering. [6] Deployment device according to any one of the preceding claims, characterized by , that the running surface (4) is formed by a web of fibrous material. [7] Deployment device according to any one of the preceding claims, characterized by, that a maintenance position is still provided, wherein the folding element (2) can be folded from the operating position to the maintenance position [8] Deployment device according to claim 7, characterized by , that means are provided to fix the folding element (2) in the maintenance position. [9] Deployment device according to any one of the preceding claims, characterized by , that a sensor is provided which detects a movement of the folding element (2) from the operating position during operation of the application device and generates a signal. [10] Deployment device according to any one of the preceding claims, characterized by , that the application device comprises a second enclosure (20) which is arranged behind the applicator (1) when viewed in the direction of travel of the surface (4), and wherein the enclosure (10) is enclosed by the second enclosure (20). [11] Ordering device according to claim 10, characterized by, that the second enclosure (20) comprises a second hinged element (2a), wherein one end of the second hinged element (2a) is movably connected to a fixed wall of the second enclosure (20) or to the applicator (1), and wherein this movable connection is designed such that a second end of the second hinged element (2a) is arranged in an operating position in the immediate vicinity of the running surface (4), and the second hinged element (2a) can be folded outwards from this operating position.

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