EP1442855B1 - Device for distributing granular material onto a continously travelling support - Google Patents

Description

The invention relates to a device for spreading coated gluten, in particular chip and fibrous goods in the course of the production of wood-based panels according to the preamble of claim 1.

In the production of wood-based panels, especially wood fiber boards, there is the problem that so-called fiber bales form by the transport of the fibers from the refiners to the actual discharge point in the scattering head. This is usually caused by wall friction, back combing, screw conveyors, etc., which cause material recirculation and combine the fibers into spherical fiber agglomerates. These fiber bales are very undesirable because they lead in the finished wood fiber board to a cloud-like surface structure and represent a visual quality deficiency.

Furthermore, in devices for the production of wood-based panels, in which a stream of glued wood particles or fibers moves, come to caking and deposits, which are then suddenly replaced by vibrations or other forces and entrained with the flow of material. These deposits usually consist of a fiber / glue mixture which is already completely cured by the long time spent lying. These deposits are referred to below as fiber / glue nodes.

These fiber / glue knots, especially in the production of thin wood-based panels of 2.5 - 8 mm and especially at high densities of 800 - 1000 N / mm ² cause severe damage to the steel strips of continuous presses.

From the DE 100 20 881 A1 and DE 100 53 129 A1 Devices are known for spreading glued scattered goods, in particular chip and fibrous goods in the course of the production of Holzwerkssoffplatten having an entry area, a storage area and a discharge area. The discharge area in this case comprises a Austragswalzenanordnung with a plurality of parallel rollers, and there is a scattering roller arrangement, by which the spreading material is aufstreubar on a continuously moving forming belt.

To dissolve the fiber bales described above, as well as for breaking the fiber / glue nodes described above are opening rollers after the dosing bunker and before the scattering head assembly, ie in the flow between dosing bunker and scattering head arrangement arranged; they rotate in opposite directions at very high speeds of 800 - 2000 revolutions per minute.

As opening rollers toothed disk rolls or spiked rollers are known, which have rows arranged on the circumference spines, which engage between the spiked rows of the opposite roller. The material flow is in this case driven by the gap formed between the sting.

In modern plants for the production of wood fiber boards with high investment capacity such fiber dissectors as double or triple roller pairs be executed, otherwise the high throughput can not be processed. Since the opening rollers are operated at high speeds, a solid frame with integrated vibration damping is required. This construction has the disadvantage that the fiber release device takes up a large amount of space. The dosing bunker and all feeders must be set one level higher. In addition to the high investment costs for the Faserauflösevorrichtung.an itself, additional costs incurred by the more expensive steel construction and the required additional hall height.

Object of the present invention is to develop a device for spreading glued grit, especially chip and fibrous goods in the course of the production of wood-based panels according to the preamble of claim 1 such that a high quality wood-based panel can be produced, and wherein a high throughput and a small footprint is achieved and continue the manufacturing and construction costs is minimized.

This object is achieved in that the rollers of the Austragswalzenanordnung are formed as provided with release elements opening rollers.

As a result, the opening rollers, which are otherwise additionally arranged between the dosing bunker and the spreading head arrangement, can be dispensed with. The fast-rotating opening rollers fulfill both the function of uniform discharge and the resolution. Due to this training height and other manufacturing costs for additional rollers is saved.

As in the discharge area of the dosing bunker, which have a conventional bunker filling height of 2000 - 3000 mm, a variety of Discharge or opening rollers can be arranged, a high throughput can be realized.

In one embodiment, it is provided that all opening rollers have the same direction of rotation, with the exception of the uppermost opening roller. Here, a good resolution of the fiber / glue nodes is achieved.

In this preferred mode of operation, first, fibers are discharged at each interface between the existing rolls, second, the relative velocities between adjacent spiked disks are significantly higher as the peripheral velocities add together, and third, a uniform down-facing fiber discharge with low air turbulence results.

In the experiments, it has surprisingly been found that the discharge works with the same direction rotating fiber opening rollers and without tendency to pulsation. Subsequent to the opening rollers, only slight air turbulences occur and the variant brings with it a downwardly directed discharge flow. The latter arises from the fact that all opening rollers turn downwards on the discharge side and thus also an air flow acts down, which entrains the very light fibers with it.

In principle, air turbulences arise at the outlet of the fiber opening rollers. These air turbulences are very disturbing as the air turbulence entrains the light fibers and thus creates an unwanted, uncontrolled distribution in the transverse direction. In order nevertheless to obtain a good scattering result and in particular to avoid an uncontrolled redistribution in the transverse direction, the invention provides, in a further development, the arrangement of wall elements which subdivide the delivery flow into a plurality of partial streams. The Wall elements are spaced from each other vertically and longitudinally to the conveying direction. In order to influence the transverse distribution, the wall elements are designed to be adjustable in one embodiment. As a result, shafts that form through the wall elements can be adjusted individually opening or closing downwards. Furthermore, this also an adjustability for the purpose of changing the spread is conceivable.

The invention will be explained in more detail with reference to exemplary embodiments which are illustrated in the drawings.

Fig. 1:

eine Seitenansicht einer Streustation mit Dosierbunker, Beruhigungsfächer sowie Streuvorrichtung;

Fig. 2a,2b:

eine Ausführungsform eines Auflösewalzenpaares in Seitenansicht und ein Teilausschnitt in Draufsicht;

Fig. 3a,3b:

eine weitere Ausführungsform eines Auflösewalzenpaares in Seitenansicht und ein Teilausschnitt in Draufsicht;

Fig. 4:

zeigt im Ausschnitt eine Frontalansicht eines Beruhigungsfächers;

Fig. 5:

eine weitere Ausführungsvariante einer Streustation mit Dosierbunker, Beruhigungsfächer und Streuvorrichtung;

Fig. 6:

eine Seitenansicht einer Streustation mit verschwenkbar ausgebildeten Teilwänden des Beruhigungsfächers;

Fig. 7a,7b:

eine Seitenansicht einer Streustation mit Beruhigungsfächer sowie Aufgabeklappe mit Leitblechen und ein Teilausschnitt des Details Führungsgabel / Leitblech;

Fig. 8:

eine Seitenansicht einer Streustation mit Expansionsraum und Luftabsaugschacht;

Fig. 9:

eine Seitenansicht einer Streustation mit Schwergutabscheider.

Show it:

Fig. 1:

a side view of a scattering station with dosing bunker, sedation and scattering device;

2a, 2b:

an embodiment of an opening roller pair in side view and a partial detail in plan view;

3a, 3b:

a further embodiment of an opening roller pair in side view and a partial detail in plan view;

4:

shows in the section a frontal view of a calming fan;

Fig. 5:

a further embodiment of a scattering station with dosing bunker, calming fans and scattering device;

Fig. 6:

a side view of a spreading station with pivotable part walls of the calming fan;

Fig. 7a, 7b:

a side view of a scattering station with calming compartments and task flap with baffles and a partial detail of the details guide fork / baffle;

Fig. 8:

a side view of a scattering station with expansion space and air extraction shaft;

Fig. 9:

a side view of a spreading station with heavy material separator.

In Fig. 1 The drawing shows schematically a scattering station 1 with a dosing bunker 2, a calming fan 3, a scattering roller assembly 4 and a forming belt 5, to which the material web 6 is sprinkled from free-flowing material spread, shown.

As free-flowing materials are lignocellulosic and / or cellulose-containing particles of different sizes such as fibers, chips and the like provided in the first place. For the production of fiberboard wood fibers are usually used provided with binders.

These glued wood fibers are introduced via a screw conveyor, not shown, in the entry area 7 of the dosing bunker 2. By means of a swiveling process, the screw conveyor distributes the fibers over the entire bunker width. At the bunker floor, a bottom band 8 is provided, to which the wood fibers are applied and which slowly conveys the entire applied fiber layer to a discharge area 10. So that the most uniform possible quantity is discharged from the dosing bunker 2, a back combing device 9 in the form of a back pressure rake 9 is provided at the top of the dosing bunker 2, by means of which a constant filling level is produced. Above the discharge area 10 opening rollers are provided over the entire bulk height, which form an opening roller assembly 11. By means of the opening roller assembly 11, the flow of wood fibers is dissolved and added to a directly downstream calming 3.

As it is from the Fig. 1 it can be seen, a plurality of individual opening rollers 12 are arranged in parallel spaced apart in the discharge area 10, wherein the opening rollers 12 are arranged starting from the bottom belt 8 in the vertical direction to the backscrap 9 out obliquely. A through the axes of rotation of the opening rollers 12 extending plane E has to a vertical V at an angle α.

From the illustration too Fig. 1 is further seen that the opening rollers 12 are driven to rotate in the counterclockwise direction (arrows 13), wherein the uppermost, the backscatter rake 9 closest opening roller 12 is driven in opposite directions rotating.

In this mode of operation, the opening rollers can be operated at low speeds of 200-800 rpm in comparison to previous fiber opening rollers.

Further details of the opening rollers 12 can the drawings to the Fig. 2a, 2b . Fig. 3a, 3b be removed.

The opening rollers 12 each have a cylindrical base body 14 formed as a rotary shaft, which are provided with a plurality of arranged on the main body spaced-apart slices 15.

Between the arranged on the opening rollers 12 adjacent slices 15 each spacer sleeves 16 are inserted. The slices 15, which are arranged axially spaced on the opening rollers 12, protrude in the middle as it from the Fig. 2b it can be seen in the interstices of the on the adjacent opening roller 12 axially spaced-release discs 15. The slices 15 are made of a spring plate. The sheet thickness of the slices 15 is 1.5 mm in this embodiment.

The dissolving discs 15 have, as it is known from Fig. 2a it can be seen, an annular portion extending from the evenly distributed over the circumference of the release elements 17 radially outward, between which recesses remain. The dissolving elements 17 are formed substantially rectangular. Furthermore, tapered recesses are provided centrally on their front sides, radially inward, so that two tips 18 are formed at each end of the opening element 17.

As indicated by the double arrow 19 in Fig. 2b 3b can be seen, the distance between adjacent rollers can be changed.

In Fig. 2a, 2b In this case, a meshing state of adjacent opening rollers 12 is shown. With Ü a measure of the overlap region of the slices 15 adjacent opening rollers 12 is designated.

In the Fig. 3a, 3b is shown a non-combing state in which the slices 15 have a gap S distance.

It should be noted at this point that the opening rollers 12 may be provided with other structurally designed release elements or spikes or the like.

The flow of glued fibers is forced through the narrow gap formed between the spikes, resulting in fiber disintegration of fiber / glue knots. The dissolved material stream is thrown after the opening roller assembly 11 in a immediately downstream arranged sedation fan 3 (arrows p, Fig. 4 )

The reassurance fan 3 consists of a housing part in which a plurality of parallel wall elements 20 are arranged. The wall elements 20 are preferably designed as longitudinally aligned to the conveying direction of the forming belt 5 sheets and divide the housing part into several calming chambers 21 (illustration Fig. 4 ).

By dividing into several calming chambers, a number of uniform partial flows are created, which are to be influenced individually in order to achieve an optimal distribution on the forming belt 5. In order to achieve such an influence, in particular in the width, at least as many wall elements 20 are provided that at least three partial flows arise. Since plate widths of up to about 3 to 4 meters are common in practice, calming fans of about eight to thirty parallel currents have proven to be advantageous. The conveying direction is vertical in order to convey the material particles from the overhead dosing bunker 2 to the scattering roller arrangement 4 arranged therebelow. However, the calming compartment 3 can also be arranged obliquely to the vertical direction in order to simultaneously achieve a horizontal conveying component. At the same time, the calming fan can also be oriented obliquely to the conveying direction in order to deflect the flow laterally.

As it is from the representation of the Fig. 1 it can be seen, the wall elements 20 are formed on their upper, the opening rollers 12 facing region, each semicircular, the contour of the opening rollers 12 corresponding recessed. In this way, the wall elements 20 can be arranged immediately following the opening roller assembly 11 and there remains only a small gap between opening rollers 12 and the upper edge of the wall elements 20 of the sedan 3. By this arrangement, no fibers can be deposited on the upper edge of the wall elements 20 and a fiber - / Leimknotenbildung can be prevented. The wall elements 20 protrude from the opening roller assembly 11 in the vertical direction until shortly beyond a task flap 22. The task flap 22 can also for the purpose of adaptation to different plate thicknesses about the axis of rotation D ( Fig. 6 ) are pivoted.

The material flow forced through the opening cylinder arrangement 11 is catapulted into the calming chambers 21 of the calming compartment 3 with high kinetic energy. The existing air streams together with the fibers are now passed as parallel partial streams in the calming chambers 21 down.
Although turbulences may occur in the individual calming chambers 21, due to the spatial limitation, however, it is prevented that a significant redistribution of the material flow in the transverse direction can occur.

Subsequent to the calming compartments 3, the partial streams directed downwards in the individual calming chambers 21 reach a task flap 22 arranged below them, which feeds the stream of material to a scattering roll arrangement 4. The scattering roller assembly 4 consists of several parallel and transversely to the conveying direction arranged scattering rollers. The spreader rollers are arranged along the conveying direction in a horizontal rising line to ensure a uniform dispersion and a height limit. The spreader rolls are provided directly below the task flap 22 and promote the flowable goods, preferably the glued wood fibers against the conveying direction. By the rotation of the scattering rollers, the wood fibers are simultaneously sprinkled onto the continuously running underneath forming belt 5 as a non-woven fabric and fed to a subsequent pre-press station or a platen press.

In a further embodiment, not shown, an additional conveying device could also be provided following the calming compartments 3, which feeds the stream of glued fibers to a spreading head arrangement 4. The additional conveying device is designed as a feeder belt, which continuously conveys a controllable flow rate in the spreading head assembly 4, so that depending on the plate thickness and width of the scattering head assembly 4 a predetermined amount is strewn on the forming belt 5.

Fig. 5 shows a further embodiment of a scattering station for spreading glued litter in the course of the production of wood fiber boards, in which the opening rollers 12 are driven in pairs in opposite directions rotating. As it is from the Fig. 5 it can be seen, in this case four pairs of opening rollers 12 are provided in the discharge region 10 of the metering bunker 2. In this arrangement, the paired opening rollers 12 must be operated at different speeds, so that at the interface, a relative speed between the opening rollers 12 is formed, which leads to a resolution of Faser./Leimknoten.

The same parts already described above are provided with the same reference numerals. The previously described different embodiments of the embodiment of the scattering station acc. of the Fig. 1 also apply to those in the Fig. 5 schematically illustrated embodiment of the scattering station 1 '.

The wall elements 20 are at least partially pivotally or slidably mounted relative to a stationary housing part, so that the distances of the wall elements 20 from each other are continuously or gradually adjustable.

In order to adapt to different plate widths to be produced or, for the purpose of influencing the material distribution in the transverse direction, an embodiment is provided in which the wall elements 20 are designed in two parts and in the lower part walls 23 which can be pivoted about an axis A by means of an adjusting mechanism 24. By this adjustment, the distance between the wall elements in the lower region can be varied at the side facing the scattering roller assembly 4 side. By the fixed wall elements 20 in the upper, the opening rollers 12 facing area, the entry of the flow of material remains in the calming chambers 21 constant.

Fig. 7a shows a scattering station 1 '''in contrast to the embodiment according to. Fig. 1 In the lower region of the task flap 22 facing baffles 26 are provided.

For this purpose, the wall elements 20, as well as the neck of the Fig. 7b it can be seen in the lower area than Guide fork 25 is formed. On the Aufgabeklappe 22 are spaced in the longitudinal direction, the wall elements 20 each assigned guide plates 26 which are slidably guided in the Führüngsgabeln 25.

As a result of this design, the partial flows of the calming chambers 21 are guided by means of the guide plates 26 as far as the spreading roller arrangement 4, so that no undesirable redistribution in the transverse direction can occur in the area of the loading flap 22.

To reduce unwanted air turbulence, which arise subsequent to the opening roller assembly 11 is in Fig. 8 illustrated a variant in which behind the opening roller assembly 11, a large-volume expansion space 27 is formed, wherein additionally via a suction duct 28, an indirect suction of the air takes place.

The high momentum created by the high-speed fiber opening rollers 12 can still be used to separate heavy material, such as glue / fiber lumps that are not dissolved or other foreign bodies, from fiber flow. This can, as it is in the Fig. 9 is shown schematically, spaced apart in front of the Austragswalzenanordnung 11 a shaft 29 are arranged with opening slots 30. The foreign bodies, which are considerably heavier than the fibers of the material flow, are thrown much further due to the high kinetic energy and, as shown by the arrow 31, pass through the opening slots 30 into the heavy material separator formed as a shaft. In the lower part of the shaft 29 there is a screw 32, which conveys the heavy parts trapped in the shaft out of the spreading device. In principle, a variant embodiment is also possible in which the formation of a calming fan is dispensed with and the dissolved material flow is applied directly to a spreading head assembly.

Claims (9)

1. Device for spreading glued spread materials, in particular chips or fibrous materials, as a part of the manufacturing of wood material panels, with a dosing hopper (2) including a feed area, a storage area and a discharge area for the spread material, said discharge area (10) comprising a discharge roller arrangement (11) with a multitude of parallel rollers (12), and with a spreader roller arrangement (4) by which the spread material may be spread onto a continuously moving forming belt (6), characterized in that the rollers (12) of the discharge roller arrangement (11) are embodied as dissolving rollers (12) equipped with dissolving elements (17).
2. Device for spreading glued spread materials according to claim 1, characterized in that the dissolving rollers (12) are arranged in pairs rotating in opposite directions, the dissolving rollers (12) of a pair rotating at different speeds.
3. Device for spreading glued spread materials according to claim 1, characterized in that all dissolving rollers (12) with the exception of the upper dissolving roller (12) in vertical direction rotate in the same sense of rotation.
4. Device for spreading glued spread materials according to one of the claims 1 to 3, characterized in that all dissolving rollers (12) are arranged in such a way that the axial distance between them is adjustable.
5. Device for spreading glued spread materials according to one of the claims 1 to 4, characterized in that directly downstream the discharge roller arrangement (11), a settling fan (3) is arranged, which comprises several wall elements (20) extending in the conveying direction and arranged in parallel to each other, said wall elements (20) forming a multitude of settling chambers (21).
6. Device for spreading glued spread materials according to claim 5, characterized in that the wall elements (20) comprise separate partial walls (23) in the area facing towards the spreader head arrangement (4), said partial walls being swivel-mounted by means of adjusting elements (24), so that the discharge in the lower area is variable in cross direction.
7. Device for spreading glued spread materials according to one of the claims 3 or 6, characterized in that the wall elements (20) are designed in such a way that they may be slidably displaced, at least in partial sections, across the direction of movement of the forming belt by means of corresponding adjusting elements.
8. Device for spreading glued spread materials according to one of the preceding claims, characterized in that an expansion space with an air suction shaft (28) is provided in the area downstream of the discharge roller arrangement (11).
9. Device for spreading glued spread materials according to one of the preceding claims, characterized in that a cutting shaft for heavy particles (29) with entry slots (30) is arranged at a distance and in parallel to the discharge roller arrangement (11) downstream of same.

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