Device and Method for the Gluing of Particles

Abstract

The invention relates to a device for the gluing of particles, in particular wood particles, including a dryer and a line transporting the stream of particles, wherein the stream of particles is being introduced in a main flow direction into the dryer via the outlet. A binder is supplied to the stream of particles, said binder being introduced via a nozzle device with a speed component directed against the main flow direction.

Claims

1. A device for the gluing of particles, comprising a dryer and a line transporting the stream of particles, wherein the stream of particles is introduced in a main flow direction into the dryer via the outlet, a binder being supplied to the stream of particles, wherein the binder is introduced via a nozzle device with a velocity component directed against the main flow direction.

2. The device of claim 1, wherein the nozzle device includes at least one jet-forming nozzle.

3. The device of claim 2, wherein the nozzle device includes three jet-forming nozzles arranged in parallel with each other.

4. The device of claim 1, wherein the nozzle direction of the at least one nozzle of the nozzle device is arranged at an angle β with respect to the main flow direction, where 90°<β<180°.

5. The device of claim 1, wherein the nozzle device is arranged downstream of the outlet, seen in the main flow direction.

6. The device of claim 5, wherein the line is arranged horizontally and the at least one nozzle of the nozzle device is oriented onto the sectional line of the horizontal centre plane of the stream of particles with the vertical outlet plane of the outlet of the line or to above this sectional line.

7. The device of claim 1, wherein the nozzle device is arranged at a section of the line located in the dryer upstream of the outlet, seen in the main flow direction.

8. The device of claim 1, wherein each nozzle has a nozzle feed line, the nozzle feed line having a diameter D and, upstream of the nozzle outlet, a straight feed line section with a length L, where: L/D>1.5.

9. A method for gluing particles, in a dryer, comprising: introducing a stream of particles into the dryer in a main flow direction and supplying a binder to the stream of particles, the binder is introduced with a velocity component directed against the main flow direction.

10. The method of claim 9, wherein the binder is introduced into the stream of particles as at least one liquid jet.

11. The method of claim 9, wherein the binder is supplied at a pressure between 5 and 40 bar.

12. The method of claim 9, wherein the binder is introduced at a velocity of at least 50 m/s at a viscosity of the binder between 30 and 150 mPa.Math.s.

Description

[0030] In the Figures:

[0031] FIG. 1 is a schematical sectional view of the dryer of a device for gluing particles according to the present invention,

[0032] FIG. 2 is a schematical detail of the nozzle device and the outlet of the line of the stream of particles of a device for gluing particles according to the present invention,

[0033] FIG. 3 is a schematical detail of the nozzle device of a device according to the present invention, and

[0034] FIG. 4 is a schematical sectional view of a nozzle of a nozzle device of the device according to the present invention.

[0035] FIG. 1 schematically shows a section through a device 1 according to the present invention for gluing particles. The device comprises a dryer 3 into which a stream of particles of a particle/vapor mixture is introduced. The dryer 3 serves to dry the particles.

[0036] The stream of particles is introduced into the dryer 3 via a line 5 carrying the stream of particles. Here, the stream of particles has a man flow direction indicated by an arrow in FIG. 1. The stream of particles leaves the line 5 at an outlet 7. Downstream of the outlet 7, seen in the main flow direction, a binder is supplied to the stream of particles via a nozzle device 9.

[0037] FIG. 2 schematically shows a detail of the end of the line 5 forming the outlet 7. The stream of particles leaves the line 5, which is also referred to as a blowline, at a high velocity through the outlet 7. When leaving the line 5 through the outlet 7 and, thus, when entering the dryer 3, the stream of particles expands.

[0038] The nozzle device 9 is fastened by a schematically indicated mount 15. The nozzle device 9 is formed by a nozzle pipe 17 in which three parallel nozzles 19 are arranged, which are best seen in FIG. 3. The nozzles 19 are jet-forming nozzles so that liquid jets of binder can be produced by means of the nozzle device. The nozzles are oriented at an angle β relative to the main flow direction which is also indicated by an arrow in FIG. 2, i.e. the nozzle direction and thus the direction of the liquid jet leaving the nozzles extend at an angle 13 with respect to the main flow direction. In the embodiment illustrated in FIG. 2, the angle β is 135°.

[0039] Thus, the nozzles 19 of the nozzle device 9 produce binder jets having a velocity component directed against the main flow direction. Thereby, it is achieved that the stream of particles conveyed through the line 5 at a high velocity collides with the binder and atomizes the same very finely, whereby an advantageous gluing of the particles of the stream of particles is obtained.

[0040] The nozzles 19 may in particular be directed on the sectional line of the horizontal centre plane 5a of the stream of particles with the vertical outlet plane 7a of the outlet 7 of the line 5. In this manner, the binder impinges on the central portion of the stream of particles in approximately the outlet plane 7a, whereby an advantageous distribution of the binder is achieved.

[0041] As best seen in FIG. 3, the nozzles 19 are supplied with binder via the common nozzle pipe 17. The nozzle pipe 17 extends under an acute angle with respect to the horizontal plane, e.g. under an angle of 10°. Thereby, it is possible to clean the nozzles 19 and the nozzle pipe 17, since these can be emptied completely using compressed air.

[0042] As best seen in FIG. 4 which schematically illustrates a single nozzle 19 in detail, each nozzle 19 has a nozzle feed line 19a with a diameter D. Upstream of the nozzle outlet 19b, a straight feed line section 19c of the nozzle feed line is provided which has a length L. Here, it holds that L/D>1.5. It is achieved thereby that the binder flowing through the nozzle 19 settles and an advantageous liquid jet of binder can leave from the nozzle outlet 19b.

[0043] When introducing the binder in a direction against the main flow direction of the stream of particles, it may be provided that the binder is introduced at a pressure between 10 and 40 bar. In particular it may be provided that the binder exits from the nozzle device 19 at a velocity of at least 50 m/s, the binder having a viscosity between 30 and 150 mPa.Math.s.