Multi-media nozzle, in particular two-media nozzle

Abstract

The invention relates to a multi-media nozzle, in particular two-medianozzle, for atomising a fluid using an atomising medium, comprising a nozzle body (1) having at least one outer tube (2), an inner tube (3) arranged in the outer tube, and a nozzle needle (4) arranged in the inner tube such that it can be moved in the longitudinal direction (L), and comprising a drive (5) for the moving of the nozzle needle (4) in the longitudinal direction (L). An inner ring channel (6) for the fluid is arranged between the nozzle needle (4) and inner tube (3) and an outer ring channel (7) for the atomising medium is arranged between the outer tube (2) and inner tube (3), wherein the inner tube (3) has an end-side outlet opening (8) for the fluid, which connects at the end to the inner ring channel (6), wherein the nozzle needle (4) can be introduced into the outlet opening (8), in order to close the outlet opening (8) with its needle end (16), in such a way that, in the closed position of the nozzle needle (4), an outer closing surface (17) surrounding the nozzle needle (4) all around the outer circumference lies against a corresponding inner closing surface (18) in the inner tube. The nozzle is characterised in that a control surface (20), formed by a control cone (19) and inclined transverse to the needle axis (A), is arranged on the nozzle needle (4) on the side of the outer closing surface (17) facing away from the needle end (16), spaced apart from said closing surface and positioned all around the outer circumference, wherein by moving the nozzle needle (4) in the longitudinal direction (L), the control surface (20) cooperates with an inner surface (21) of the inner ring channel (6) in such a way that the through-flow through the inner ring channel (6) can be changed.

Description

[0001] The invention relates to a gluing device for coating free-flowing particles, in particular wood fibers or wood chips, comprising a gluing chamber into which the particles to be coated can be introduced and one or more multi-component nozzles arranged in or on the gluing chamber, wherein the particles in the chamber can be sprayed with a liquid glue via the multi-component nozzles. The gluing nozzles are designed as two-component nozzles for atomizing a liquid glue using an atomizing medium. The multi-component nozzle has a nozzle body comprising at least an outer tube, an inner tube arranged (concentrically) in the outer tube, and a nozzle needle arranged (concentrically) and displaceable in the (axial) longitudinal direction within the inner tube, and a drive for displacing the nozzle needle in the longitudinal direction. wherein an inner annular channel for the liquid is arranged between the nozzle needle and the inner tube and an outer annular channel for the atomizing medium is arranged between the outer tube and the inner tube, wherein the inner tube has an end outlet opening for the liquid or the glue which connects at its end to the second annular channel, wherein the nozzle needle can be inserted into the outlet opening with its needle end in such a way that an outer closing surface circumferentially around the outside of the nozzle needle rests against a corresponding inner closing surface in the inner tube in the closed position of the needle.

[0002] Such a multi-component nozzle, which is particularly designed as a two-component nozzle, is intended for atomizing a liquid, namely adhesive, using an atomizing medium. This is a multi-component nozzle, for example, a two-component nozzle for applying adhesive to free-flowing particles, e.g., in the wood-based panel industry. The liquid is, in particular, a liquid binder, e.g., a glue, adhesive, or the like. The atomizing medium is preferably air, and especially compressed air. Alternatively, another gas or a vapor, e.g., water vapor, especially pressurized water vapor, can also be used as the atomizing medium.

[0003] The invention therefore relates to a gluing device with at least one such nozzle.

[0004] In the production of wood-based panels, such as particleboard, fiberboard, or similar products, particles, such as wood chips, wood fibers, or the like, are used as raw material and then bonded with a liquid adhesive. These bonded particles are then used to create, for example, a granulate mat, which is pressed into a wood-based panel using a press. These presses can be either intermittent or continuous-flow presses. The bonding of the fibers is of particular importance in the production of wood-based panels. The properties of the finished panel, such as its tensile strength across its width, depend significantly on the quality of the bonding, for example, on the amount of adhesive used.

[0005] Examples of adhesives or binders used in the production of wood-based panels include isocyanates, melamine-urea-formaldehyde (resins), urea-formaldehyde (resins), urea-formaldehyde (resins), melamine resins, phenolic resins or other resins, e.g. based on polyamines or tannins.

[0006] Various gluing devices are available in practice, each equipped with multi-component nozzles, particularly two-component nozzles, for atomizing the adhesive using an atomizing medium. These can be, for example, devices for blowline gluing. Alternatively, devices for mixer gluing are used. Furthermore, such a device can also be designed for drop-chute gluing. The use of the gluing nozzles for spraying the adhesive onto the particles to be glued is always of particular importance.

[0007] German patent DE 102 47 412 C5 describes a system for the drop-chute gluing of fibers for the production of fiberboard, in which fibers are pneumatically fed from above into a drop chute. The drop chute is equipped with a gluing device with spray nozzles for spraying the fibers exiting the fiber discharge pipe and entering the drop chute with glue.

[0008] DE 10 2009 057 916 B4 describes a device and a method for continuously mixing fibers with a binder for the production of fiberboard, in which one or more rotating mixing shafts with attached mixing tools are arranged in a (drum-like) mixing chamber, the mixing tools mixing the fibers with a binder and conveying them through the mixing chamber in one direction. The binder is supplied via glue nozzles, which are either fixed to the mixing chamber and project into it, or which can alternatively be arranged on the rotating mixing shaft.

[0009] Alternatively, a blowline gluing process is described, for example, in DE 10 2011 103 326 B4, in which the particles to be glued are transported through a blow line to which several nozzles are connected, each leading into the blow line. These nozzles are designed as multi-component nozzles, e.g., two-component nozzles for vapor atomization. At least one glue supply line and one vapor supply line are connected to each two-component nozzle. At least one glue valve and one flow meter are integrated into each glue supply line. The glue valves and the flow meter are connected to at least one control and / or regulating device, so that the flow rate for each glue supply line can be controlled or regulated separately using the glue valves.

[0010] The various known methods of gluing have generally proven effective in practice. The same applies to the nozzles used in such devices or processes. In such multi-component nozzles, e.g., two-component nozzles, a needle is typically displaceable axially within an inner tube, e.g., by means of a pneumatic drive. In the prior art, this longitudinally displaceable needle serves, firstly, to close the nozzle's end outlet by being inserted into the outlet so that an outer closing surface circumferentially around the nozzle needle rests against a corresponding inner closing surface in the inner tube or at the nozzle end. Secondly, the nozzle needle can be used to clean the nozzle outlet, e.g., by squeezing out glue residue to prevent blockages.Therefore, in state-of-the-art technology, the nozzle needle typically has a sealing function on the one hand and a cleaning function on the other.

[0011] In practice, additional control or regulating valves are used to control or regulate the spraying process and consequently the amount of liquid sprayed by the nozzle. While this allows for precise adjustment and therefore a perfect gluing result, the necessary components (especially control or regulating valves) involve (additional) costs. The invention aims to remedy this.

[0012] A two-component nozzle for external mixing of viscous and / or dilatant liquids with an atomizing medium is known, for example, from DE 20 2010 05 280 U1.

[0013] DE 37 12 798 A1 further describes a device for the continuous recovery of organic polymers from their solutions or emulsions, in which a two-component nozzle projects from below through the bottom of a vessel. This nozzle consists of an outer sheath and an inner sleeve, an intervening outer channel, and an inner channel in which a nozzle needle is centrally and slidably arranged. The needle end and the inner sleeve are conically tapered, forming a conical annular gap whose width can be changed by adjusting the nozzle needle. The nozzle needle also has a separate sealing seat formed by sealing surfaces. The device is used for the continuous recovery of organic polymers from their solutions or emulsions.

[0014] Furthermore, DE 26 55 224 A1 discloses a device for atomizing liquids with a spray nozzle, which includes a valve for controlling the size of the outlet opening. This device incorporates a manually adjustable cam assembly, interacting with a control valve, for controlling the size of the outlet opening and for controlling changes in its size. The control valve comprises a needle valve, the needle of which is slidably mounted relative to the valve seat, and the outlet opening is formed by the gap between the needle and the seat. The cam assembly is designed such that the size and degree of movement of the needle are controlled in a predetermined manner to control the size of the outlet opening and to control changes in its size.

[0015] US Patent 2007 / 0199539 A1 describes a device for the separate supply of a liquid fuel and a gaseous fuel to the combustion chamber of an internal combustion engine. This device comprises a first valve and a second valve, which are combined within the device. One valve is used to expel a liquid fuel, and the other valve is used to expel a gaseous fuel.

[0016] US patent 2014 / 0034023 A1 discloses a fuel nozzle in which a liquid fuel is expelled via a central channel and a central opening, while a gaseous fuel is expelled via openings directed obliquely outwards.

[0017] Furthermore, DE 10 2004 060 151 A1 describes a nozzle assembly of an injector nozzle which contains several injection holes for several rows of injection holes of a nozzle assembly. The injection holes are connected to the same annular channel, with only one supply via the high-pressure bore being provided, through which the fuel is supplied under very high pressure.

[0018] Finally, DE 33 36 665 A1 describes, in connection with the moistening of free-flowing solids, a nozzle for the high-pressure atomization of liquids such as glue, wherein the spray nozzle has a housing with a piston rod axially displaceable within it, the molded outer end of which interacts with the inner edge of a nozzle opening. An inlet port leads into the housing, which is connected to a branch line for supplying the glue under high pressure. The piston rod is pneumatically adjustable via a compressed-air-actuated piston.

[0019] The invention is based on the objective of creating a gluing device with at least one multi-component nozzle, in particular a two-component nozzle, which is characterized by a simple design and simple operation and in particular enables variable operation with simple means.

[0020] To solve this problem, the invention teaches a gluing device with the features of claim 1. This device has at least one multi-component nozzle in which, on the side of the outer closing surface facing away from the needle end, a control surface formed by a control cone and inclined obliquely to the nozzle axis or needle axis is additionally arranged on the outer circumference, wherein, by displacing the nozzle needle in the longitudinal direction, the control surface interacts with an inner surface of the annular channel in such a way that the flow rate (or the flow quantity) through the second annular channel can be changed.

[0021] The invention is based on the understanding that the nozzle needle, which is already present in the multi-component nozzle and is longitudinally displaceable, can be used not only as a sealing and cleaning needle, but also for controlling or regulating the flow rate of the liquid, particularly the glue. Thus, the liquid output of the nozzle can be varied and, in particular, controlled or regulated by moving the nozzle needle longitudinally. A particularly advantageous feature is that separate control valves or regulating valves in the glue supply area can be dispensed with, making the nozzle especially economical to use.According to the invention, this is achieved by providing the nozzle rod not only with a closing surface in its "front" area associated with the nozzle outlet, but also with a control cone in its "rear" area, and consequently in the area facing away from the needle end. This control cone has an inclined control surface that interacts with a corresponding inner surface of the inner annular channel in such a way that the flow rate through the second annular channel can be increased by moving the nozzle needle in one longitudinal direction, and decreased by moving it in the opposite longitudinal direction. This movement can be achieved very simply with one and the same drive that is already used for moving the nozzle needle for closing and cleaning.The drive is preferably designed as a pneumatic drive in a generally known manner, comprising a piston connected to the nozzle needle, guided in a cylinder, and pressurized with a pressure medium as a control medium, e.g., compressed air. The drive or its cylinder can be integrated, for example, into the nozzle body or into a separate housing connected to the nozzle body. Thus, the multi-component nozzle, particularly a two-component nozzle, can simply have one connection for the liquid (i.e., glue), one connection for the atomizing medium (e.g., air, compressed air, or steam), and one connection for the control medium (e.g., compressed air). By controlling the compressed air to actuate the nozzle needle, not only is the nozzle closed or cleaned, but the flow rate is also controlled, thereby controlling the spray quantity / regulating the amount of liquid to be atomized.

[0022] The nozzle needle can be subjected to force in the closing direction, e.g., by means of a closing spring; that is, the closing spring pushes the nozzle needle into the closed position, i.e., towards the nozzle outlet opening. Conversely, the pressure medium acting on the piston allows the nozzle rod to move in the opening direction.

[0023] Of particular importance is the control cone connected to the nozzle needle, which can, for example, be manufactured as a single piece with the nozzle needle and is therefore an integral part of the correspondingly shaped nozzle needle. This control cone is provided in addition to the closing surfaces already present in the area of ​​the outlet end of the nozzle needle, specifically – with respect to the closing surface – on the side of the nozzle needle opposite the piston end. This means that the control cone is arranged on the nozzle rod between the end-side closing surface and the piston-side end of the nozzle rod.

[0024] In one possible embodiment, the control cone is designed such that the displacement direction of the nozzle needle for closing the nozzle (i.e., the closing direction) is oriented opposite to the displacement direction for reducing the flow. In this embodiment, the nozzle needle (e.g., with the pneumatic actuator) is moved in the closing direction, i.e., towards the outlet end, to close the nozzle, while actuation in the opposite direction occurs to reduce the flow. In this embodiment, the control cone is preferably tapered in the opposite direction to the closing direction. This means that the control cone preferably tapers away from the outlet end of the nozzle.

[0025] Alternatively, the control cone can be designed such that the displacement direction of the nozzle needle for closing the nozzle (i.e., the closing direction) corresponds to the displacement direction for reducing the flow. In this embodiment, the flow is reduced and the nozzle needle is closed in the same direction. In this embodiment, the control cone preferably tapers in the closing direction, i.e., it tapers towards the nozzle outlet.

[0026] The inner annular channel is formed between the nozzle needle and the inner tube. In the area of ​​exclusively cylindrical surfaces between the nozzle needle and the inner wall of the inner tube, the cross-section of the inner annular channel does not change as the nozzle rod is moved. However, due to the inclined control surface in the area of ​​the control cone, the cross-section of the nozzle channel changes as the nozzle rod is moved axially, thus influencing the flow rate of the liquid through the inner annular channel.

[0027] In one embodiment of the invention, the inner surface of the inner annular channel, which interacts with the control cone, is arranged between the (end) closing surface on the one hand and the inlet opening for the liquid into the nozzle body on the other. In this embodiment, the inner surface of the inner annular channel, which interacts with the control cone, is therefore preferably arranged at a distance in the flow direction from the inlet opening for the liquid. The same applies to the control cone, which is therefore arranged at a distance in the flow direction from the inlet opening for the liquid in all operating positions.

[0028] In an alternative embodiment, the control cone with its control surface can also be arranged (directly) in the area of ​​the liquid inlet. The control cone is thus arranged to overlap the inlet at least partially, so that the liquid, as it flows into the nozzle body, passes directly into the area of ​​the control cone via the inlet. In this case as well, the flow rate can be varied by moving the nozzle rod and thus by moving the control cone. Furthermore, in this embodiment, the inner surface of the inner annular channel associated with the control cone is not inclined or slanted, but rather the annular channel is cylindrical in this area, and consequently the inner surface is not inclined or slanted. For further details, please refer to the description of the figures.

[0029] For supplying the aforementioned media, the nozzle body has, firstly, the previously mentioned inlet opening, which is connected to the inner annular channel and serves for supplying the liquid, i.e., the adhesive. Furthermore, the nozzle body has a second inlet opening connected to the outer annular channel for the atomizing medium. An inlet nozzle and / or a corresponding line for supplying the media can be connected to each of these inlet openings.

[0030] Furthermore, a third inlet opening or connection nozzle is provided, which serves to supply compressed air to the cylinder or piston.

[0031] The gluing device is also preferably equipped with or connected to a suitable control system, which in particular controls the compressed air for positioning the nozzle rod, since this actuation is used to close and clean the nozzle as well as to control or regulate the flow rate and consequently the spray quantity.

[0032] As mentioned, air, compressed air, or even steam can be used as the atomizing medium. The pressure of the control medium is, for example, 1 bar to 6 bar, preferably 1.5 bar to 4.5 bar.

[0033] Air or compressed air can be used as the control medium. The pressure can be, for example, 1 to 6 bar.

[0034] The revealed nozzle, despite its simple design, is characterized by homogeneous atomization and very low susceptibility to clogging. The nozzle is drip-free and particularly easy to control or regulate, as the design already incorporates the necessary control or regulation mechanisms, eliminating the need for separate control or regulating valves.

[0035] The invention relates – as described – to a gluing device for applying glue to free-flowing particles, in particular wood fibers or wood chips, comprising a gluing chamber into which the particles to be glued can be inserted (and removed) and / or through which the particles to be glued can be passed. Furthermore, this gluing device has one or more multi-component nozzles, in particular two-component nozzles of the type described, with which the particles in the chamber are sprayed with glue.

[0036] In a first embodiment, the gluing device is designed as a blowline gluing device, i.e., a blow line is provided as a gluing chamber through which the particles to be glued are transported, wherein several nozzles of the described type opening into the blow line are connected to the blow line, which are preferably distributed along the blow line and with which the particles transported through the blow line are sprayed with glue.

[0037] In a second embodiment, the gluing device is designed as a mixer-gluing device, i.e., the gluing chamber is formed by a drum-like mixing chamber in which one or more mixing tools rotate, the mixing tools preferably being attached to a rotating mixer shaft. The fibers are mixed with the binder by means of the mixing tools and conveyed through the mixing chamber in one direction. Such a gluing mixer is also equipped with the multi-component nozzles, which are preferably integrated into or connected to the wall of the mixing chamber. Optionally, the gluing nozzles can also be arranged on the rotating mixer shaft.

[0038] In a third embodiment, the gluing device is designed as a drop-chute gluing device. This device has a vertically oriented drop chute into which the particles to be glued are fed at the top by a feed device. The drop chute is equipped, in particular at the top, with a gluing device having several spray nozzles of the type described, which are designed to spray the fibers exiting a fiber discharge tube and entering the drop chute with drops of glue or the like. At the outlet end, i.e., at the lower end, the drop chute is equipped with a collecting device and / or a transport device for collecting and / or removing the fibers. The design of known drop-chute gluing devices can be used for this purpose (see, e.g., DE 102 47 412 C5).The invention will now be explained in more detail with reference to drawings, which merely illustrate exemplary embodiments. They show... Fig. 1 a first embodiment of a two-fluid nozzle according to the invention in a vertical section, Fig. 2a a second embodiment of the invention in a first functional position, Fig. 2b the subject matter according to Fig. 2a in a second functional position, Fig. 2c the object towards Fig. 2a in a third functional position, Fig. 3a a third embodiment in a first functional position and Fig. 3b the object according to Fig. 3a in a second functional position.

[0039] The figures show, in different embodiments, a multi-component nozzle for atomizing a liquid using an atomizing medium. The exemplary embodiments each show a two-component nozzle. The liquid is a liquid binder, namely an adhesive for bonding wood-based material particles during the production of wood-based panels. Air (compressed air) or, alternatively, steam can be used as the atomizing medium.

[0040] The two-fluid nozzle has a nozzle body 1 comprising an outer tube 2, an inner tube 3 arranged concentrically in the outer tube 2, and a nozzle needle 4 arranged concentrically in the inner tube so as to be displaceable in an (axial) longitudinal direction L. A drive 5 is provided for displacing the nozzle needle 4; in this embodiment, the drive is a pneumatic drive.

[0041] An inner annular channel 6 for the liquid (i.e., the adhesive) is provided between the nozzle needle 4 and the inner tube 3. An outer annular channel 7 for the atomizing medium (e.g., air or compressed air) is provided between the outer tube 2 and the inner tube 3. The inner tube 3 has an end outlet 8 for the liquid, which is connected to the inner annular channel 6. The two-component nozzle also has an end opening 9 for the atomizing medium, preferably an annular opening surrounding the end outlet 8 for the liquid, so that an annular atomizing jet impinges on the concentric liquid jet on its outer circumference and atomizes the liquid.

[0042] The nozzle body 1 also has an inlet opening 10 for the liquid, which is connected to or opens into the inner annular channel 6. Furthermore, the nozzle body 1 has a second inlet opening 11 for the atomizing medium, which is connected to or opens into the outer annular channel 7. Suitable connecting nozzles 10a, 11a or corresponding lines can be connected to these inlet openings 10, 11. A third inlet opening 12 for the compressed air supply is also provided for driving the nozzle rod; this opening can in turn be connected to a suitable compressed air nozzle or compressed air line 12a. This opening 12 can also be located in the nozzle body or in the outer annular channel 7. Fig. 1 shown - provided in an attached housing part of the drive 5.

[0043] Fig. 1 Figure 1 shows a first embodiment of such a two-fluid nozzle in a functional position for spraying, i.e., with the nozzle open. The liquid to be sprayed enters the inner annular channel 6 via the nozzle 10a and the inlet opening 10, and from there into the area of ​​the end outlet opening 8. The atomizing medium enters the outer annular channel 7 via the nozzle 11a and the second inlet opening 11, and from there, via the opening 9, also into the area of ​​the nozzle end. The nozzle needle 4, which can also be referred to as the nozzle rod, can be moved along the longitudinal direction L by means of the drive 5. In particular, the nozzle needle 4 can be moved along the longitudinal direction L in the closing direction S towards the nozzle end, thus closing the nozzle.The nozzle needle 4, with its needle end 16, can be inserted into the outlet opening 8 in such a way that an outer closing surface 17, circumferentially running around the outside of the nozzle needle 4, abuts a corresponding inner closing surface 18 in the inner tube. This closed position is in . Fig. 1 Indicated by a dash.

[0044] According to the invention, a control surface 20, formed by a control cone 19 and inclined obliquely to the nozzle axis or needle axis A, is additionally provided on the nozzle needle 4. This control cone 19 is arranged – with respect to the aforementioned closing surface 17 – on the side of the nozzle needle facing away from the needle end 16, i.e., the closing surface 17 is arranged between the control cone 19 and the needle end 16. By displacing the nozzle needle 4 along the longitudinal direction L, the control surface 20 interacts with a corresponding inner surface 21 of the inner annular channel 6 in such a way that the flow rate or flow quantity through the second annular channel 6 is changed. Fig. 1 It is evident that in the area of ​​the control cone 19, the channel section 6a between the control surface 20 and the inner surface 21 changes when the nozzle needle 4 is moved upwards or downwards along its longitudinal direction. Therefore, according to the invention, the flow rate can be controlled or regulated very simply by moving the nozzle needle 4, without the need for additional control or regulating valves in the (external) supply line for the liquid.

[0045] In the embodiment according to Fig. 1 The control cone 19 and inner surface 21 are oriented such that the displacement direction of the nozzle needle 4 for closing the nozzle, and consequently the closing direction S, is opposite to the displacement direction R for reducing the flow. Therefore, Fig. 1 If the nozzle needle 4 is moved along the closing direction S (downwards) to close, the nozzle needle 4 must be moved in the direction R (upwards) to reduce the flow rate.

[0046] In this embodiment, both the control surface 20 and the inner surface 21 are oriented at an angle to the axis A of the nozzle. Furthermore, in the embodiment according to Fig. 1 It is provided that the inner surface 21 and also the control cone 19 or its control surface 20 (in all functional positions) are positioned between the closing surfaces 17, 18 on the one hand and the inlet opening 10 for the liquid on the other.

[0047] The actuator 5 is – as already mentioned – designed as a pneumatic actuator, comprising a piston 13 connected to the nozzle needle 4 and guided in a cylinder 14. The cylinder 14, and thus the piston 13, can be pressurized with a pressure medium, e.g., compressed air (i.e., control air), via the previously mentioned compressed air connection 12 or 12a. The cylinder 14 can be part of the nozzle body or connected to this nozzle body as a separate assembly or housing part. The piston 13, and thus also the nozzle needle, is subjected to force, e.g., by means of a spring 15. In the illustrated embodiments, the spring 15 acts as a closing spring, pressing the piston 13, and thus also the nozzle needle 4, in the closing direction. That is, without compressed air being applied, the closing spring 15 pushes the nozzle needle 4 into the closed position, which is Fig. 1 The diagram is only indicated by a dotted line. Using compressed air, the piston 13, and thus the nozzle needle 4, can be moved along the opening direction (opposite the closing direction). By controlling the compressed air (control air), the flow rate can be controlled or regulated in the manner described.

[0048] The Fig. 2a , 2b and 2c show a second embodiment of the invention, which differs in its functioning from the first embodiment according to Fig. 1 This corresponds to the following. In this embodiment as well, the nozzle needle 4 is acted upon in the closed position by the closing spring 5. This closed position is in Fig. 2a shown. By applying compressed air, the nozzle needle 4 can be moved into the position shown. Fig. 2b Lift the working position shown. In this embodiment, the end-side closing surfaces 17, 18 and the control surface 20 on the control cone 19, which interacts with the inner surface 21 of the inner annular channel 6, are also visible. Fig. 2b This shows the working position in which the channel section 6a provided in this area is open and allows the flow of liquid in the desired quantity. Fig. 2c This shows a third functional position in which the nozzle needle 4 is moved to its upper end position by maximum compressed air pressure, so that the control cone 19 with the corresponding inner surface 21 completely closes the annular channel 6. Therefore, this also applies to the Fig. 2a bis 2c It is provided that the displacement direction of the nozzle needle for closing the nozzle and consequently the closing direction S is oriented opposite to the displacement direction for reducing the flow.

[0049] In contrast, the Fig. 3a und 3b A third embodiment, in which, for example, the displacement direction for closing the nozzle needle and consequently the closing direction S is oriented in the same direction as the displacement direction for reducing R the flow rate. Whereas in the embodiment according to Fig. 1 or 2a to 2c, the control cone widens in the closing direction, in the embodiment according to Fig. 3 A reduction of the control cone in the closing direction is achieved, i.e., the diameter is reduced in the closing direction. Fig. 3a The nozzle is initially shown in an open position, with the liquid entering the inner annular channel 6 via the inlet. In contrast, it shows Fig. 3b The nozzle in the closed position, in which the needle end 16 of the nozzle needle 4 closes the outlet opening 18. A comparative analysis of the Fig. 3a und 3b shows that by varying the position of the nozzle needle between these two end positions using the control cone 19, the flow rate can be varied.

[0050] The following show Fig. 3a und 3b An exemplary embodiment in which the control cone 19 is arranged in the area of ​​the inlet opening 10 for the liquid.

[0051] The two-component nozzle shown in the figures is preferably used for gluing free-flowing particles, especially wood fibers or wood chips. Such a gluing nozzle is integrated into a gluing device. This gluing device can be a blowline gluing device, a drop-chute gluing device, or a mixer gluing device. Details are not shown in the figures.

Claims

1. An adhesive application device for applying adhesive to spreadable particles, more particularly to wood fibres or wood chips, with an adhesive application chamber into which the particles to which adhesive is be applied can be introduced, or through which the particles to which adhesive is to be applied can be passed, and with one or more multi-fluid nozzles arranged in or on the adhesive application chamber, wherein the multi-fluid nozzles are configured for the spraying of fluid adhesive with the aid of air or steam as the atomisation medium, wherein via the multi-fluid nozzles, the particles in the chamber can be sprayed with a fluid adhesive, wherein the adhesive application nozzle comprises a nozzle body (1) having at least one outer pipe (2), an inner pipe (3) arranged in the outer pipe and a nozzle needle (4) arranged in the inner pipe so as to be displaceable in the longitudinal direction (L), and wherein the adhesive application nozzle comprises a drive (5) for the displacement of the nozzle needle (4) in the longitudinal direction (L), wherein arranged between the nozzle needle (4) and inner pipe (3) is an inner ring channel (6) for the adhesive and between the outer pipe (2) and inner pipe (3) is an outer ring channel (7) for the atomisation medium, wherein at one end, the inner pipe (3) has an outlet opening (8) for the adhesive which adjoins the inner ring channel (6) at one end, wherein to close the outlet opening, the nozzle needle (4) is introducible with its needle end (16) into the outlet opening (8) in such a way that in the closing position of the nozzle needle (4), a closing surface (17) surrounding the nozzle needle (4) on its outer circumference fits closely against a corresponding inner closing surface (18) in the inner pipe, wherein arranged on the nozzle needle (4), on the side of the outer closing surface (17) facing away from the needle end (16), at a distance from this, also on the outer circumference, is a control surface (20) that is formed by a control cone (19) and inclined at an angle to the needle axis (A), wherein through displacement of the nozzle needle (4) in the longitudinal direction (L) the control surface (20) interacts with an inner surface (21) of the inner ring channel (6) in such a way that the throughflow through the inner ring channel (6) is alterable.

2. The adhesive application device according to claim 1, characterised in that the control cone (19) is designed in such a way that the displacement direction (S) of the nozzle needle (4) for closing the nozzle is opposite to the displacement direction (R) for reducing the throughflow.

3. The adhesive application device according to claim 1, characterised in that the control cone (19) is designed in such a way that the displacement direction (S) of the nozzle needle (4) for closing the nozzle corresponds to the displacement direction for reducing the throughflow.

4. The adhesive application device according to any one of claims 1 to 3, characterised in that the control cone (19) and the control surface (20) are arranged between an inlet opening (10) for the adhesive into the nozzle body on the one hand, and the outer closing surface (17) on the other hand.

5. The adhesive application device according to any one of claims 1 to 3, characterised in that the control cone (19) and the control surface (20) are arranged in the area of an inlet opening (10) for the fluid arranged in the nozzle body.

6. The adhesive application device according to any one of claims 1 to 5, characterised in that the control surface (20) is orientated at an angle to the longitudinal direction or to the needle axis (A) and in that the corresponding inner surface (21) of the inner ring channel (6) is orientated at an angle to the longitudinal direction (L) or to the needle axis (A) or in parallel thereto.

7. The adhesive application device according to any one of claims 1 to 6, characterised in that the drive (5) is designed in the form of a pneumatic drive that comprises a piston (13) that is connected to the needle nozzle (4), is guided in a cylinder (14) and to which a pressure medium can be applied.

8. The adhesive application device according to any one of claims 1 to 7, characterised in that the nozzle needle (4), can have a force applied to it, e.g. via the piston (13), in the closing direction (S), e.g. by means of a closing spring (15).

9. The adhesive application device according to any one of claims 1 to 8 in the embodiment as an adhesive application mixing device, with a drum-like adhesive application chamber and one or more mixer tools rotating in the adhesive application chamber.

10. The adhesive application device according to any one of claims 1 to 8, in the embodiment as a blow line adhesive application device with a blow line that forms the adhesive application chamber and to which the multi-fluid nozzles are connected.

11. The adhesive application device according to any one of claims 1 to 8 in the embodiment as a chute adhesive application device with an adhesive application chamber designed in the form of a chute and with several multi-fluid nozzles arranged on the chute or above the chute.

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