DEVICE AND METHOD FOR WETTING PARTICLES

Abstract

A device for wetting particles, in particular wood particles, with an application agent, at least one conduit transporting a fluid as a fluid stream and an end section which forms an outlet. The fluid can be introduced in the direction of the main flow into a container containing the particles, via the outlet. The particles are in the container in a loosened state and/or can be loosened. The application agent, for spraying by a nozzle device with a speed component directed against the main flow direction, can be introduced into the fluid stream and can be guided to the particles by the fluid stream.

Claims

1-15. (canceled)

16. A device for wetting particles, in particular wood particles, with an application agent, said device comprising: at least one conduit transporting a fluid as a fluid stream and having an end section which forms an outlet, wherein, via the outlet, the fluid can be introduced in a main flow direction into a container containing the particles, wherein the particles in the container are in a loosened state and/or in a state adapted to be loosened, wherein the application agent, for being sprayed, can be introduced into the fluid stream by a nozzle device with a speed component directed against the main flow direction and can be applied to the particles by the fluid stream.

17. The device according to claim 16, wherein the container is formed by a drum, wherein the particles can be circulated within the drum.

18. The device according to claim 17, wherein the drum is rotatable and/or a circulation of the particles is performed pneumatically.

19. The device according to claim 16, wherein the nozzle device comprises at least one jet-forming nozzle.

20. The device according to claim 19, wherein the nozzle direction of the at least one nozzle of the nozzle device is arranged at an angle relative to the main flow direction, wherein there applies: 90<<180.

21. The device according to claim 16, wherein the nozzle device, when viewed in the main flow direction, is arranged behind the outlet.

22. The device according to claim 16, wherein the end section of the conduit comprises a flow device for accelerating the fluid stream.

23. The device according to claim 22, wherein the flow device comprises a tapering of the cross section of the end section toward the outlet.

24. The device according to claim 16, wherein an annular space surrounds the end section of the conduit, said annular space being connected to the conduit and opening into the container.

25. A method for wetting particles, in particular wood particles, with an application agent, comprising: a fluid is fed in the form of a fluid stream in a main flow direction into a container containing the particles, wherein the particles in the container are in a loosened state and/or will be loosened, wherein the application agent, for being sprayed is introduced into the fluid stream with a speed component directed against the main flow direction and the atomized application agent is supplied to the particles by means of the fluid stream.

26. The method according to claim 25, wherein the application agent is introduced into the fluid stream in the form of at least one liquid jet.

27. The method according to claim 25, wherein the application agent is introduced with a pressure in the range from 3 to 40 bar.

28. The method according to claim 25, wherein the application agent is introduced at a speed of at least 10 msec with a viscosity of the application agent in the range from 30 to 150 mPa.Math.s.

29. The method according to claim 25, wherein the fluid stream is accelerated prior to entering the container.

30. The method according to claim 25, wherein an annular flow surrounding the fluid stream is generated that is introduced into the container.

Description

[0037] The invention will be explained in greater detail hereunder with reference to the Figures briefly outlined below.

[0038] The following is shown:

[0039] FIG. 1 is a schematic sectional view of the device 1 according to the invention,

[0040] FIG. 2 is a schematic detailed view of the outlet device,

[0041] FIG. 2a is a schematic detailed view of the nozzle in FIG. 2, and

[0042] FIG. 3 is a schematic plan view onto the outlet of the outlet device in FIG. 2.

[0043] In FIG. 1, a device 1 according to the invention, provided for wetting particles 3, is schematically shown in sectional view. Device 1 comprises a container 5 which is designed as a drum 7. Within container 5, the particles 3 can be loosened. For this purpose, said drum 7 comprises a rotatable enclosure 9 with circulating fixtures 11 arranged internally of it. Upon rotation of enclosure 9, the particles will be entrained and will fall down under the effect of gravity, thereby being loosened.

[0044] Container 5 comprises a feed device, not shown, and a discharge device, said devices being operative to feed the particles to drum 7 and, respectively, to discharge them from the latter. Container 5 can be arranged e.g. at an oblique orientation so as to allow for a gravity-induced transport of the particles 3 through drum 7.

[0045] In the interior of drum 7, three application devices 13 are arranged which are operative to feed an application agent, e.g. a binding agent, to the particles 3.

[0046] Said outlet devices 13 are arranged at predefined mutual distances on a mounting structure 15 within drum 7. By means of the outlet devices 13, a fluid stream 17 inclusive of application agent atomized in it will be introduced into drum 7.

[0047] In FIG. 2, an outlet device 13 is schematically shown in sectional view.

[0048] Outlet device 13 comprises a conduit 19 for transporting a fluid in the form of a fluid stream, said outlet device comprising an end section 21 forming an outlet 23. The fluid transported in the form of a fluid stream via said conduit 19 will be introduced, in a main flow direction, into container 5. In FIG. 2, the main flow direction is indicated by an arrow.

[0049] By means of a nozzle device 25, the application agent can be introduced into the fluid stream with a speed component directed against the main flow direction. Thereby, the application agent will be atomized and distributed in the fluid stream so that, by means of the fluid stream, the application agent can be fed to the particles 3.

[0050] The fluid can be e.g. air.

[0051] Nozzle device 25 comprises a jet-forming nozzle 27 which is shown in greater detail in FIG. 2a. Said nozzle 27 comprises a nozzle feed conduit 27a. The nozzle feed conduit 19a has a diameter D. Before the nozzle exit 27b, there is formed a straight-lined feed section 27c having a length L, wherein: L:D>1.5. Thereby, it is safeguarded that application agent being fed via nozzle device 25 will have sufficiently calmed down before exiting from nozzle 27 via nozzle exit 27b and that the nozzle 27 will be able to form a clear-shaped jet of application agent.

[0052] Said nozzle 27 has a nozzle direction arranged at an angle relative to the main flow direction, wherein, in FIG. 2, the angle is about 150. Thereby, the application agent fed by means of nozzle device 25 is given a relatively high speed component which directed against the main flow direction. Thus, the fluid flowing through outlet 23 will hit upon the application agent, wherein this collision will accomplish a fine atomization and distribution of the application agent in the fluid stream.

[0053] In the exemplary embodiment shown in FIG. 2, the end section 21 is oriented horizontally, and the nozzle 27 of nozzle device 25 is oriented onto the line of intersection of the horizontal central plane 23a of the agent stream with the vertical outlet plane 23b of the outlet 23. This orientation can also be provided above this line of intersection. Such an arrangement has turned out to be of particular advantage for the atomization of the application agent.

[0054] Outlet device 13 is fastened to mounting structure 15 via an articulation device 29. By means of the articulation device 29, the application device 13 can be pivoted in various directions, thus allowing for an optimal orientation toward the particles 3. Conduit 19 is connected, via a schematically indicated flexible conduit 19a, to a compressornot shownvia which the fluid can be fed at a high speed to outlet 23. Nozzle device 25 is connected, via a likewise schematically indicated flexible conduit 25a, to a tanknot shownfor the application agent.

[0055] End section 21 of conduit 19 comprises a flow device 31 serving for accelerating the fluid stream. Said flow device is designed as a nozzle, wherein the cross section of end section 21 is tapering toward outlet 23.

[0056] In FIG. 3, a plan view of outlet 23 is schematically shown. As can be seen in FIG. 3, the cross section of outlet 23 has a trapezoidal shape. Thereby, it is achieved that the mass flow of the fluid stream which leaves the outlet 23 in the lower region is relatively large, so that a support flow will be formed which will support the overlying portion of the fluid stream, thus rendering it possible that the fluid stream with the atomized application agent can be transported relatively far within drum 7.

[0057] As best visible in FIG. 2, outlet device 13 further comprises an annular space 33 surrounding the end section 21, said annular space being connected to the conduit 19 on the end facing away from outlet 23. By means of the annular space, there is generated an annular flow which, when exiting from outlet device 13, will lay itself around the fluid stream comprising the atomized application agent. With the aid of this annular flow, the expansion behavior of fluid stream with the atomized application agent can be influenced in an advantageous manner, thus allowing for the formation of a long fluid stream within drum 7 without the risk of application agent escaping from the fluid stream. Thereby, the application agent can be applied to the particles 3 in atomized form in an advantageous manner.

[0058] The application agent can be introduced at a pressure in the range from 3 to 40 bar. In the process, the application agent can have a speed of at least 10 m/sec with a viscosity of the application agent in the range from 30 to 150 mPa.Math.s.

[0059] The fluid stream can be e.g. air. The application agent can be a binding agent or also another agent for improving the properties of the particles. The particles can be, for instance, wood particles, e.g. wood fibers.