EP2197639B1 - Particulate-material installation - Google Patents

Description

The invention relates to a grit plant for scattering (glued) grit on a scattering belt conveyor, on grit screens or the like grit transport, to form grit mats for the production of wood-based panels or in the course of the production of wood-based panels, with at least one Streu bunker aufzustreuende on the scattering belt conveyor Scattering material, at least one arranged above the grit hopper screw conveyor device with at least one screw in a screw driven screw conveyor for filling the grit hopper and at least one chute between a discharge opening of the screw housing and a filling opening of the grit hopper. - Wood-based panels means within the scope of the invention, in particular fiberboard, z. As MDF (Medium Density Fiber), or chipboard or OSB boards. Such a grit bunker is designed, for example, as a horizontal bunker, which has a bottom-side dosing belt and a dosing belt end-assigned discharge device, for. B. Austragswalzenfront with multiple discharge rollers for discharging grit on the scatter band conveyor. The scatter belt conveyor is usually arranged below the grit hopper. In the upper region, such a grit bunker preferably has an upper conveyor, z. B. scratches, which initially conveys the grit entering the bunker in the rear of the grit hopper. This is to ensure that the grit bin works on the principle of "first in - first out". This is especially in the processing of glued spreading material, z. B. glued MDF fibers of importance, so that the first entering the grit hopper fibers are also first removed from this and scattered on the grit conveyor. The bottom-side dosing is also called Bunker bottom band called. With the dosing belt speed, the volumetric flow of the material to be spread out of the spreading material bunker can be adjusted. In this respect, such a grit plant preferably works in continuous operation and in particular in the course of the continuous production of wood-based panels in z. B. a continuous press. However, the invention also includes grit systems for tact presses, z. B. one-floor or multi-day presses, in which the grit from the bunker not on a continuous spreading belt conveyor, but z. B. is scattered on grit screens or the like.

Such grit systems are known from practice in various embodiments. They have basically proven themselves. It is of particular importance that with the help of such a grit plant grit mats perfect quality and in particular uniform spreading material distribution to be applied to the scatter belt conveyor. For this reason, it is known to sprinkle the grit from the grit hopper not directly on the scattering, sondem first on a scattering head, which may be formed, for example, as Streuwalzenstraße and can ensure a uniform spreading of the grit. Moreover, it is known in this context to provide a Streugutverdichtungsauflöser between the Austragswalzenanordnung the grit hopper and the scattering head or the Streuwalzenstraße, which has two opening rollers (see. DE 43 02 850 C2 ).

Furthermore, there is known a device for producing scattered mat, in which the spreading material is scattered by one or more conveyors on a fiber distribution or Auflösevorrichtung on the scattering belt conveyor. This device for loosening or distributing fibers is immediate arranged above the scatter belt conveyor and has two superimposed pairs of rollers, which rotate in opposite directions with circumferentially arranged interlocking elements (see. US 3,252,186 ).

The US 4,192,417 describes a feeder for a bottom belt bunker for receiving and discharging fiber or chip material according to the preamble of claim 1. It extends in the upper region of the bottom belt bunker transversely to the direction of movement of the bottom belt a worm with pitch-like, opposite worm gears. This snail is partially covered by a slider. The length of the slider should be changeable or adjustable in relatively small limits in order to adjust the length of the slider depending on the material to be used. If chips are scattered and then fibers are to be scattered, then the length is slightly larger. The same applies if the filler opening during a longer period less material must be supplied as was the case previously. Incidentally, the slider is reciprocable.

From the DE 24 32 571 Incidentally, a device for discharging spreading material, in particular for depositing chips in the course of the production of particleboard and the like is known, in which a screw conveyor with driven worm shaft and a screw cylinder is provided, which extends across the width of a bunker and upstream feeding device and a drop is provided. The worm cylinder has a helical circumferential discharge slot extending across the width of the bunker. In this case, the worm cylinder is driven in rotation. In this way, a uniform ejection of grit long reached the discharge line.

Incidentally, a screw conveyor with a pair of parallel twin screws is basically known, which has a pressure-tight cover for the discharge opening which can be displaced by means of adjusting devices in the longitudinal direction of the screw. This screw conveyor finds its use among others in mining or civil engineering (see. DE 88 16 651 U1 ). Such proposals had no influence on the development of gritters for the wood-based panels industry.

The invention has for its object to provide a grit system of the type described above, which allows the production of flawless grit mats with a simple and inexpensive construction and proper operation.

To solve this problem, the invention teaches in a generic grit system of the type described above, that the screw conveyor in the discharge opening to vary the discharge position has at least one displaceable discharge insert and that within the chute, at least one brake roller device is arranged, which has at least two rotationally driven brake rollers , The discharge insert is preferably displaceable at least along the screw longitudinal direction.

The invention is based on the recognition that the quality of the grit mats generated in such a grit plant depends not only on the structure and operation of the grit hopper, his discharge roller front and in particular the scattering head, but that the way of filling the grit hopper a Influence on the distribution of the material to be spread on the Streubandbörderer downstream Streubandförderer has or can have. In this case, the invention has recognized that it is possible to produce grit mats of high quality when the grit bunker is filled in a perfect manner. For this purpose, the invention proposes a variation of the discharge position already in the area of the screw conveyor, which supplies the spreading material bunker the grit. This is particularly useful because within the chute, at least one brake roller device is arranged, which has at least two rotationally driven brake rollers. Such brake rollers are preferably spaced by a predetermined amount and arranged with substantially parallel axes so that they do not mesh. It is expedient if the brake rollers are arranged approximately at the same height and therefore side by side. Consequently, the spreading material does not enter the bunker via the chute unbraked, but via the brake rollers. These not only reduce the speed of falling through the chute fibers, but also provide for a turbulence or distribution of the fibers, so that compaction of the material to be spread, which can occur when hitting the material to be spread into the bunker can be reliably avoided. Such a brake roller device now works in a particularly advantageous manner when the discharge position of the material to be spread can be adjusted or varied above the brake roller device via the discharge insert according to the invention. Thus, taking into account given empirical values or also by experiments, the optimum discharge position can be adjusted taking into account, for example, the rotational speed of the brake rollers or similar parameters. In this respect, the invention provides a combination of the described screw conveyor device with the described brake roller device under protection.

Preferably, such a screw conveyor device not only has a single screw conveyor, but at least two substantially parallel to the axis side by side arranged augers, which are preferably housed in a single screw housing and work in a common direction of conveyance. These two or more augers is associated with a common discharge opening and also preferably a common displaceable discharge insert. These juxtaposed augers rotate preferably in opposite directions. By two juxtaposed counter-rotating screw conveyor, the grit hopper can be filled with high volume flow, with the adjustable ejection insert optimal adaptation to the circumstances, in particular taking into account the described brake roller devices is made possible.

In one possible development of the invention, alternatively or additionally, at least two substantially coaxial or axially parallel augers are provided, which operate in opposite directions of conveyance and consequently to one another. According to a possible embodiment, a total of four or more conveying screws can be used in combination with the above-described conveying screws, with two conveying screws each being arranged next to one another and working in the same conveying direction. In an embodiment with at least two oppositely arranged augers, the invention proposes that these preferably work on a common discharge opening and that each auger or auger pair is associated with a separate discharge insert.

Furthermore, the invention proposes that the delivery housing has one or more cylindrical or partially cylindrical guide shells associated with the screw conveyor or screws, which cover at least the lower region of the screw conveyors, wherein the screw conveyors rotate in these guide shells or guide tubs. The z. B. two juxtaposed guide shells can be combined to form a common guide trough or double trough (or double trough). In the discharge area, these guide shells then have at least one discharge opening. In that regard, it may be the discharge opening of the screw housing or even arranged within the screw housing discharge opening.

The discharge insert is adapted in its shape or in its cross section to the shape or the cross section of the guide shells. Thus, the discharge application z. B. move or adjust below the guide shells. In particular, in one embodiment with a pair of screws or with two juxtaposed snails, the invention proposes that the discharge insert as z. B. wedge-shaped or zwickelförmiger insert between two juxtaposed augers is arranged. Such a wedge-shaped discharge insert preferably has two arcuate shell sections, wherein each of these arcuate shell sections is associated with a screw conveyor.

The inventive variation or adjustment of the discharge position can be done manually according to a proposal of the invention, wherein the optimal discharge position z. B. is adjusted by experiments or taking into account previously obtained empirical values. In the optimal discharge position, a locking of the discharge insert may be provided in or on the worm housing. However, it is also within the scope of the invention that the Abwurfeinsatz is remotely adjustable and therefore can be moved automatically. For this purpose, at least one suitable drive can be provided. In that regard, it may be an electric motor drive or a cylinder piston assembly, for. B. a hydraulic and / or pneumatic actuator cylinder act.

In this context, it is also possible to vary the position of the discharge insert via a suitable control and / or regulation during the discharge operation or during the filling of the bunker.

• Fig. 1 eine erfindungsgemäße Streugutanlage in einer vereinfachten Seitenansicht,
• Fig.2 einen vergrößerten Ausschnitt aus dem Gegenstand nach Fig. 1,
• Fig. 3 eine schematische Draufsicht auf den Gegenstand nach Fig. 2,
• Fig. 4 eine vereinfachte Ansicht aus Richtung des Pfeils A auf den Gegenstand nach Fig. 2,
• Fig. 5 den Gegenstand nach Fig. 2 in einer abgewandelten Ausführungsform,
• Fig. 6 eine vereinfachte Draufsicht auf den Gegenstand nach Fig. 5,
• Fig. 7 einen vereinfachten (perspektivischen) Ausschnitt aus dem Gegenstand nach Fig. 2 in abgewandelter Ausführungsform
• Fig. 8 einen Ausschnitt aus der Vorrichtung nach Fig. 1 im Bereich der Bremswalzen,
• Fig. 9 eine Ansicht des Gegenstandes nach Fig. 8 aus Richtung des Pfeils C,
• Fig. 10 einen Schnitt durch eine Stachelwalze gemäß Fig. 9.

In the following the invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment:

• Fig. 1 a sprue plant according to the invention in a simplified side view,
• Fig.2 an enlarged section of the object after Fig. 1 .
• Fig. 3 a schematic plan view of the object Fig. 2 .
• Fig. 4 a simplified view from the direction of the arrow A on the object Fig. 2 .
• Fig. 5 the object after Fig. 2 in a modified embodiment,
• Fig. 6 a simplified plan view of the object after Fig. 5 .
• Fig. 7 a simplified (perspective) section of the object after Fig. 2 in a modified embodiment
• Fig. 8 a section of the device according to Fig. 1 in the area of the brake rollers,
• Fig. 9 a view of the object after Fig. 8 from the direction of the arrow C,
• Fig. 10 a section through a spiked roller according to Fig. 9 ,

In the figures, a grit plant for scattering of grit on a scatter belt conveyor 1 to form grit mats 2 for the production of wood-based panels is shown in fragmentary form. The spreading material may in particular be MDF fibers for the production of MDF boards. This grit plant has a grit hopper 3 for the scattered material to be sprinkled on the scatter belt conveyor 1. Above the grit hopper 3, a screw conveyor 10 is arranged to fill the grit hopper. This screw conveyor device 10 has at least one auger 19a, 19b driven in rotation in a screw housing 18. Between the auger device 10 and the grit hopper 3 arranged below a chute 5 is arranged, which is connected at its upper end to a discharge opening 20 of the screw housing 18 and at its lower end to a filling opening 4 of the grit hopper 3. About this chute 5, the grit enters the grit hopper. The grit hopper 3 is formed in the embodiment as a horizontal bunker with a bottom-side dosing belt 6, which is also referred to as bunker bottom belt 6. At the end, the dosing belt 6 is followed by a discharge device which, as the discharge roller front 7, has a discharge device Discharge rollers is formed. In the upper part of the bunker 3, an upper conveyor is indicated, which acts as a scratch, z. B. chain scraper 8 is formed. The working direction of the dosing belt 6 on the one hand and the scraper 8 on the other hand are also indicated. In this respect, it can be seen that the spreading material enters via the chute 5 in the region of the scraper 8 and from there first into the rear area of the bunker 3 is conveyed. From there it passes via the dosing belt 6 into the area of the discharge roller front 7, which throws the spreading material out of the bunker 3 onto the scatter belt conveyor 1 arranged below the bunker 3. It can be seen that the grit from the bunker 3 does not impinge directly on the scatter belt conveyor 1, but that on the applicator roller 7, the grit first occurs once on a scattering head 9, which is formed in the embodiment as Streuwalzenstraße with a plurality of scattering rollers. From there, the grit passes to form the grit mat 2 on the scatter belt conveyor 1. Typically, the scattering head 9 different mat treatment facilities are arranged downstream, z. As a Egalisiereinheit and / or a pre-press before the grit mat enters the hot press.

In the chute, and consequently in the fiber flow between screw conveyor device and grit hopper, a brake roller device 11 is arranged in the invention, which has two rotationally driven brake rollers 12. The brake rollers 12 are arranged at a predetermined distance from one another with axes arranged substantially parallel to one another. The brake rollers 12 are formed in the embodiment as spiked rollers, each having a plurality of spikes 13, which extend substantially in the radial direction.

According to the invention, the screw conveyor 10 in the region of the discharge opening 20 for varying the discharge position on at least one displaceable discharge insert 21, 21a, 21b. For this purpose, first of all, the embodiment according to Fig. 2 to 4 directed. The discharge insert 21 is displaceable along the screw longitudinal direction. In some figures (eg Fig. 3 ) are different positions of the discharge insert 21 and 21 a, 21 b indicated. The screw conveyor 10 has two substantially parallel to the axis arranged side by side screw conveyors 19a, which are arranged in a common screw housing 18. These are therefore twin screws 19a. The two adjacent augers 19a operate in a common conveying direction F1, but they rotate in opposite directions. The two screw conveyors 19a is associated with a common discharge opening 20. In addition, a single common discharge insert 21 is provided, which - as in Fig. 2 is indicated displaced to vary the discharge position. In this way, in particular in cooperation with the illustrated brake rollers 12, an optimized filling of the bunker 3, which in turn has a positive effect on the quality of the grit mats 2 produced. In particular in Fig. 3 It can be seen that the two conveyor screws 19a arranged next to each other in the longitudinal direction of the screw have screw flights arranged offset to one another, ie the screw conveyors 19a are arranged "as if in a gap". This arrangement does not change during operation, because the screw conveyors 19a rotate at the same speed or rotational speed and are preferably synchronized with each other. This ensures a permanent relative arrangement "on the gap". Taking into account the illustrated opposite direction of rotation material transport in the direction of the screw center or the screw space is ensured, which in particular material deposits avoids. This applies in particular in connection with the configuration of the ejection insert and the guide shells explained below.

In the modified embodiment of the Fig. 5 to 7 not only a single pair of augers is provided, but there are two opposite auger pairs, ie on the one hand (right) two adjacent auger 19a, which operate in one conveying direction F1 and opposite (left) two further juxtaposed augers 19b, which in the entgegengesetzen Conveying direction F2 work. All of these four screw conveyors 19a, 19b work on a common discharge opening 20, wherein each of the two screw conveyor pairs 19a and 19b each have their own discharge insert 21a or 21b associated with the invention (each independently) are displaceable. Also in this embodiment, the above-described arrangement of the respective screw pairs is provided "on the gap".

Within the conveyor housing 18 are the screw conveyors 19a, 19b cylindrical or partially cylindrical guide shells 22 assigned, which are arranged below the screw conveyors 19a, 19b and have the discharge openings 20 in the discharge area, or open into the discharge opening.

Especially in the Fig. 4 or 7 it can be seen that the ejection insert 21 is adapted in its shape or in its cross section to the shape or the cross section of the guide shells 22, so that the ejection insert 21 can be properly moved below (or above) the guide shells 22 to the discharge position, set. The ejection insert 21 (or 21a, 21b) is wedge-shaped or chisel-shaped in the exemplary embodiment and, as it were, between two adjacent conveyor screws 19a (or 19b). positioned. This is for example on the Fig. 4 and 7 directed. Consequently, each discharge insert 21 (or 21a, 21b) has two arcuate shell portions 23, each of the arcuate shell portions 23 being associated with a screw conveyor. The gusset insert can according to Fig. 7 a vertical or straight front edge 24 or z. B. according to Fig. 2 have an oblique or rounded front edge 24. The adapted shell portions of the gusset insert 21 (or 21a, 21b), in particular in combination with the opposite direction of rotation of the screws 19a (or 19b) ensures proper operation, as in particular material deposits are avoided. The twin screws push the material, as it were, inwards over the gusset or its shell sections in the direction of the discharge opening. The adaptation of the gusset insert to the worm housing and the worms avoids dead spaces and settling of the grit. This is particularly advantageous because it is preferably glued grit. As already explained above, the screws preferably rotate at the same speed. For this purpose, a single drive can be provided for a pair of screws, so that a mechanical synchronization takes place. However, the screws can also be provided with separate drives, so that then provided via the drives synchronization. The common speed can be fixed. However, the screws can also be operated with a variable or adjustable speed, it is advantageous if this variable speed for the two screws of a pair of screws is set identical, in particular to guarantee the above-described offset.

The discharge insert 21 and the discharge inserts 21a, 21b are moved manually in the embodiment, ie the discharge position is manually set, where the ejection insert is then locked if necessary in a suitable position. However, there is also the possibility of an automatic adjustment or a remote adjustment. This is not shown in the figures. In any case, it is expedient if the discharge application over z. B. lateral guide elements 16 is guided.

Incidentally, the show Fig. 8 to 10 Details of the arranged in the fiber flow brake rollers 12. It is - as explained - to spiked rollers 12 with a plurality of spikes 13. For this purpose, each spiked roller 12 has a plurality of fixed to the shaft 14 spiked combs 15 which extend over the entire width of the spiked roller , The individual spiked combs 15 are each arranged in pairs at a predetermined angle α to each other. In the embodiment, six spiked combs 15 are provided, which are each arranged in pairs at an identical angle to each other, wherein the angle is 60 ° in the embodiment. Each of these spiked combs 15 is formed as a one-piece manufactured spiked plate. The individual spiked plates 15 are screwed to the shaft and thus releasably connected to the shaft.

Incidentally, it can be seen in the figures that not only the spiked rollers 12 according to the invention are arranged in the chute 5, but that a pendulum chute 17 is provided above the spiked rollers 12 and consequently between the screw conveyor 10 and the spiked rollers 12 in the chute Trough or movable pipe section may be formed and provides by a pendulum movement for a distributed loading of the chute with grit. The interaction of this pendulum chute 17 with on the one hand the brake rollers 12 and on the other hand, the sliding ejection insert 21, 21 a according to the invention, 21b leads to particularly good scattering results. The pendulum chute 17 is z. In Fig. 2 indicated. She commutes z. B. along the longitudinal direction of the rollers 12, that is, the pendulum axis is preferably transverse to the axis of rotation of the rollers 12th

Claims (14)

1. A spreading material plant for purposes of spreading material onto a spreader belt conveyor (1), or onto spreading material screens, with the formation of spreading material mats (2), with

   - at least one spreading material bunker (3) for the spreading material to be spread onto the spreader belt conveyor (1),

   - at least one screw conveyor device (10), arranged above the spreading material bunker (3), with at least one rotationally driven screw conveyor (19a, 19b) in a screw housing (18), for purposes of filling the spreading material bunker (3), and

   - at least one drop shaft (5) between a discharge opening (20) of the screw housing (18) and a filler opening (4) of the spreading material bunker (3),

   wherein in the region of the discharge opening (20) the screw conveyor device (10) has at least one movable discharge insert (21, 21 a, 21 b) for purposes of varying the discharge position,
   characterised in that
   at least one braking roller device (11) is arranged within the drop shaft (5), which device has at least two rotationally driven braking rollers (12).
2. The plant in accordance with claim 1, characterised in that the spreading material bunker (4) is designed as a horizontal bunker with at least one metering conveyor at floor level, together with at least one delivery device assigned to one end of the metering conveyor for purposes of delivering spreading material to a spreader belt conveyor (1) arranged underneath the bunker (4).
3. The plant in accordance with claim 1 or 2, characterised in that the discharge insert (21, 21 a, 21 b) can be moved at least along the longitudinal direction of the screw.
4. The plant in accordance with one of the claims 1 to 3, characterised in that the screw conveyor device (10) has at least two screw conveyors (19a), arranged side-by-side, with parallel axes in a screw housing (18), which screw conveyors operate in a common direction of delivery (F1), wherein a common discharge opening (20) and a common discharge insert (21) is assigned to the screw conveyors (19a).
5. The plant in accordance with claim 4, characterised in that the screw conveyors (19a), arranged side-by-side, rotate in opposite directions.
6. The plant in accordance with claim 5, characterised in that the screw conveyors (19a), arranged side-by-side, have screw pitches arranged displaced relative to one another in the longitudinal direction of the screws.
7. The plant in accordance with claim 6, characterised in that the screw conveyors (19a), arranged side-by-side, rotate with the same number of revolutions per minute, or the same rotational speed, and are synchronised with one another.
8. The plant in accordance with one of the claims 1 to 7, characterised in that the screw conveyor device (10) has at least two screw conveyors (19a, 19b) arranged coaxially, or opposite one another with parallel axes, which operate in opposed directions of delivery (F1, F2, respectively).
9. The plant in accordance with claim 8, characterised in that a common discharge opening (20) and in each case a separate discharge insert (21 a, 21 b) are assigned to the screw conveyors (19a, 19b) arranged opposite one another.
10. The plant in accordance with one of the claims 1 to 9, characterised in that the delivery housing (18) has one or a plurality of the cylindrical or part-cylindrical guide trays (22) assigned to the screw conveyors (19a, 19b), which trays have an underside discharge opening in the discharge region.
11. The plant in accordance with claim 10, characterised in that in its shape the discharge insert (21, 21 a, 21 b) is matched to the shape of the guide trays (22).
12. The plant in accordance with claim 11, characterised in that the discharge insert (21, 21 a, 21 b) is arranged as a wedge-shaped or gusset-shaped insert between two screw conveyors (19a, 19b) arranged side-by-side, and has two curved tray sections (23), each assigned to a screw.
13. The plant in accordance with one of the claims 1 to 12, characterised in that the discharge insert (21, 21 a, 21 b) can be moved and locked manually.
14. The plant in accordance with one of the claims 1 to 13, characterised in that the discharge insert (21, 21 a, 21 b) can be adjusted remotely.

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