CN111918754B

CN111918754B - Method for producing a bulk mat on a spreading conveyor belt

Info

Publication number: CN111918754B
Application number: CN201980022904.5A
Authority: CN
Inventors: W·施罗德
Original assignee: Siempelkamp Maschinen und Anlagenbau GmbH and Co KG
Current assignee: Siempelkamp Maschinen und Anlagenbau GmbH and Co KG
Priority date: 2018-03-28
Filing date: 2019-02-22
Publication date: 2022-08-23
Anticipated expiration: 2039-02-22
Also published as: CN111918754A; WO2019185250A1; EP3774245B1; DE102018107354A1; EP3774245A1; PL3774245T3

Abstract

The invention relates to a spreading device (1) for producing a mat of bulk material on a spreading conveyor belt (2) in the manufacture of a board of wood material, the scattering device has at least one scattering bin (3) and a scattering head (4) arranged below the scattering bin and above the scattering conveyor belt, wherein the scattering head has a plurality of scattering rollers (5) distributed in the transport direction (T) which scatter the scattering material onto a scattering conveyor belt, wherein the spreading head comprises at least two spreading zones (4a, 4b) arranged one behind the other with different roller geometries and/or different roller modes of operation, wherein a switching device (10) is provided between the bulk silo and the scattering head, by means of which switching device the bulk material flow can be selectively directed from the bulk silo either only onto a first scattering region or only onto a second scattering region of the scattering head.

Description

Method for producing a bulk mat on a spreading conveyor belt

Technical Field

The invention relates to a spreading device for producing a mat of bulk material on a spreading conveyor belt in the production of wood material boards, having at least one bulk material silo and a spreading head arranged below the bulk material silo and above the spreading conveyor belt, wherein the spreading head has a plurality of spreading rollers (preferably driven in a rotating manner) distributed in a transport direction (of the spreading conveyor belt) which spread the bulk material onto the spreading conveyor belt, wherein the spreading head comprises at least two spreading regions arranged one behind the other with different roller geometries and/or different roller operating modes.

Background

In the context of the present invention, wood material boards are understood to mean, in particular, fiber boards, such as medium density fiber boards (MDF), or chipboards or Oriented Strand Boards (OSB). The bulk material is thus a bulk material containing lignocellulose, in particular wood fibers, wood chips or wood shavings (which are also referred to as coarse wood chips). It is therefore preferred to use fine materials, such as wood fibres or fine wood chips, in order to obtain a high-quality board surface with good properties in terms of paintability or paintability. Other materials, such as long wood chips, shavings or non-wood layers, are also used in order to improve other properties, such as bending resistance, shear resistance, tensile resistance, screw pull resistance, millability. Other ingredients are also used in order to improve the economics of the manufacturing process and to use certain residual products in non-critical layers, and such ingredients are not lost in order to create value. In this connection, it is known to produce multilayered wood material boards from different components and thus from different bulk materials.

The bulk material is preferably provided with a binder and is therefore designed as a gummed bulk material. The (glued) bulk material is initially temporarily stored in a bulk silo which serves as a material buffer and is preferably designed as a dosing silo. For this purpose, the bulk silo preferably has a dosing unit which is designed, for example, as a (driven) silo bottom belt. The silo preferably also has a discharge unit, which is designed, for example, as a discharge roll surface (Austragswalzenfront). Finally, a discharge shaft is preferably connected to the discharge section of the silo, which is arranged, for example, between the bulk silo and the spreading head, so that material passes from the bulk silo through the discharge shaft onto the spreading head. The scattering head scatters and distributes the material onto a scattering conveyor belt, on which a scattering mat is continuously constructed during transport. The bulk mat is fed, if necessary after further intermediate steps, such as prepressing, equalizing (egalisieren), moistening, etc., into a press in which the bulk mat is pressed into a wood material board using pressure and/or heat. The press may be a continuously operating press, for example a double belt press or a rotary press, for example a single-or multi-layer press.

The spreading head of such a spreading device, which usually has a plurality of spreading rollers arranged one after the other in the longitudinal direction, is in practice usually structurally adapted to the material (for example fibres or wood chips) to be treated with it. On the one hand, this relates to the roller geometry, i.e. both to the structure and geometry of the individual rollers and to the arrangement of the rollers relative to one another, for example their spacing. The adaptation also relates to the way in which the rollers are arranged in the scattering head, for example the direction of rotation and/or the speed of the rollers. In this way, the distribution head is optimized in practice for a specific material type. Furthermore, the scattering head is designed for different orientation directions with respect to the roller geometry and/or the roller mode of operation, i.e., the scattering head is provided on the one hand for the longitudinal orientation of the bulk material and on the other hand for the transverse orientation of the bulk material. Finally, the spreading head is also designed for a specific sorting direction of the bulk material (relative to the mat cross section), so that sorting is effected in the cross section, for example, in such a way that coarser material is spread to the mat core and finer material is spread to the mat surface. Roller geometries (e.g. disk rollers, lickerin rollers, etc.) which are best suited for different purposes are known in principle from practice.

If a device for producing wood-based material boards is equipped with only one spreading head or with a plurality of identically designed spreading heads for a plurality of layers, the device is usually designed only for one mat type and therefore also for one board type, so that only very limited possibilities for modification are possible with regard to the product to be produced.

In practice, therefore, it has been proposed to equip a production plant with a plurality of scattering heads arranged one after the other, which are designed differently and are optimized for different types of bulk material or types of plate, so that only one such scattering machine or a group of scattering machines is then used for a particular product. Although such a device can be used flexibly for different material or pad types, it is nevertheless distinguished by very high investment costs and a very long construction and therefore by very high space requirements. In addition to this, there is a corresponding need for a material flow for variably feeding the individual spreaders, so that such a variably usable production plant has economic disadvantages.

Furthermore, a spreading device for producing a bulk material mat and a method for operating such a spreading device are known from DE 102016109987 a1, in which the spreading head has at least one first feed region and at least one second feed region spaced apart from the at least one first feed region along or against the production direction for feeding the bulk material and/or in which at least one, preferably all, of the rollers of the roller arrangement are adapted to change their direction of rotation. The spreading head therefore has differently designed roller regions which are designed, for example, for different orientations, for example, longitudinally or transversely. The pad structure can be influenced by selecting the corresponding output opening and by selecting the direction of rotation of the dispersing device. Thus, for example, by selecting the discharge opening and by selecting the direction of rotation of the rollers, it is possible to first deposit a fine chip fraction onto the transverse orientation device and a coarse chip fraction onto the longitudinal orientation device; or vice versa, i.e. coarse wood chips are first laid on the transverse orienting device and fine wood chips are laid on the longitudinal orienting device. There is thus the possibility of influencing the order of the layers and thus the layer structure during spreading of the mat.

Disclosure of Invention

The object of the present invention is to provide a distribution device in a plant for producing wood material boards, which allows flexible production of different products, in particular also in the case of different material types, in a compact design or with a small space requirement.

To solve this task, the present invention teaches a spreading device. The scattering device has a scattering bunker and a scattering head arranged below the scattering bunker and above the scattering conveyor belt, wherein the scattering head has a plurality of scattering rollers (preferably arranged directly above the scattering conveyor belt) distributed in the transport direction (of the scattering conveyor belt) which scatter the scattering material (directly) onto the scattering conveyor belt on which the scattering material mat is formed,

wherein the spreading head has at least two spreading regions arranged one behind the other, which have different roller geometries and/or different roller modes of operation,

wherein a switching device is provided between the bulk silo and the spreading head, with which switching device the bulk material flow is selectively directed from the bulk silo either only onto a first spreading region or only onto a second spreading region of the spreading head. According to the invention, the deflecting device is thus designed and can be adjusted in such a way that only one of the distribution areas is supplied with material at all times.

The invention proceeds from the recognition that if a spreading head with two different spreading regions is provided, which has (only one single) spreading bin and a spreading head assigned to it, a spreading device can be used variably, which can be selected specifically via a switching device, to be precise in such a way that only one of the two regions is always fed, which is optimally adapted to the respectively desired properties of the bulk material and/or the plate, wherein the spreading region used can be selected very simply and quickly by means of the switching device, so that a quick and flexible adaptation of the spreading device (which is also referred to as a spreader) can be achieved.

The two scattering areas are preferably characterized by different roller geometries. This means that different roll types can be used in the two spreading zones and therefore rolls with different structures and/or geometries, for example lickerin rolls or disk rolls, can be used. Furthermore, different roller geometries, for example, also relate to different arrangements of the same or different rollers, for example different roller spacings, so that in the two dispersion zones, although the same roller type can be provided, the same roller type is provided in a different arrangement or with a different spacing. Alternatively or additionally, the two different spreading zones differ in different roller modes of operation, i.e. they can in principle have the same roller geometry, but the rollers can be operated in different modes of operation, for example in different directions of rotation and/or at different speeds. The two spreading regions always lead to different spreading results on the spreading conveyor during operation.

In a particularly advantageous embodiment, the two spreading regions of the spreading head are configured structurally for different bulk materials and thus for different types of bulk materials, for example for fine spreading material (in particular fiber, dust or chip covering material) on the one hand or coarse spreading material (for example chips or shavings) on the other hand. Such a dispensing head is preferably assigned to a single dispensing bin which can be selectively filled with different types of bulk material. It is thus possible to treat different materials in a very compact manner with the same spreader. The same bulk silo can be filled with different materials, depending on the requirements, and the distribution area of the distribution head, which is optimally adapted to the bulk material, can be selected accordingly via the switching device. This aspect is particularly notable in installations in which a plurality of spreading devices (spreaders) are arranged one after the other in the transport direction of the spreading conveyor belt in order to produce a multi-layered bulk mat. In practice, there is a need to produce bulk material mats made of a plurality of layers made of different materials or different compositions, for example, a thin material for the cover layers and a thick material for the central layer. If a plurality of scattering devices according to the invention are arranged one after the other, by selectively filling the individual scattering silos and by selecting the respective scattering area, it is possible to select a single scattering machine for a specific material type (i.e. a specific composition) and thus then adapt it to the desired product.

In principle, however, the invention also includes embodiments in which the same scattering material in the scattering bunker is used to select a corresponding scattering area in order to orient and/or sort the bulk material in a different manner. For example, one spreading region for the longitudinal orientation of the bulk material and another spreading region for the transverse orientation of the bulk material can be formed by corresponding roller arrangements, i.e., on the one hand a roller for the longitudinal orientation and on the other hand a roller for the transverse orientation. Such roller types are known in principle from the prior art. It is also known to provide a specific component separation in the dispersing head by means of roller geometry and/or roller operation, for example: in a specific direction, first the finer material arrives on the spreading conveyor and then the coarser material arrives on the spreading conveyor in order to influence the layer structure. In one possible embodiment, the first distribution region can be designed for the sorting of one component and the second distribution region can be designed for the sorting of another (for example, oppositely directed) component, so that depending on the selection of the distribution region, different component sorting relative to the pad cross section is achieved. In this case, only one of the distribution regions of the distribution head is always used, which is optimally adapted to the particular purpose.

The selection of the scattering area is accordingly effected via a switching device arranged between the scattering bin and the scattering head. The material always arrives from the bulk bunker in the same manner in the region of the switching device, which, however, can be constructed differently in terms of construction. The switching device can be arranged completely or partially in the already mentioned blanking shaft between the bulk bin and the scattering head.

In a first embodiment, the switching device has at least one adjustable guide element, for example an adjustable switching flap, for changing the direction of the dispersion flow and thus for selecting the dispersion area. The adjustable switching flap can be, for example, a switching flap which is pivotable about a pivot axis which is oriented parallel to the roller axis of the roller of the dispensing head, wherein the pivot axis is preferably arranged at the lower end of the switching flap.

In the second embodiment, the switching device can have a roller device or be designed as a roller device having a plurality of switching rollers which can be switched in their direction of rotation. All the material from the bulk silo can thus reach such a switching roller and, depending on the direction of rotation, the switching roller conveys the material either onto the first spreading region or onto the second spreading region of the spreading head. This embodiment can also be combined with the above-mentioned switching flap or adjustable guide element, so that the switching device has an adjustable guide element on the one hand and a roller device on the other hand, wherein the adjustable guide element is preferably arranged above the roller device.

In a third embodiment, the switching device may not be only a single switching flap, but rather may have a plurality of adjustable guide elements, so that such guide elements form, for example, within the blanking shaft, product constrictions that are variable in the blanking shaft. Such a product constriction can also be combined, for example, with an additional roller arrangement to form a switching device.

In all three embodiments or combinations of the three embodiments of the invention, the switching device may additionally have a fixed guide element, for example a wedge or the like, which clearly separates the two spreading zones of the spreading head from one another, so that in practice only one of the two spreading zones is fed.

As already mentioned, in a production plant for producing boards of wood material, a plurality of spreading devices or spreaders are usually arranged in combination with one another, for example one after the other in the transport direction of the conveyor belt. The invention therefore also relates to a scattering device having a plurality of scattering means of this type, which are arranged one behind the other in the transport direction of the scattering conveyor and are oriented in opposite directions to one another if necessary. However, all spreading devices of such a spreading installation are usually spread on the same spreading belt (or spreading conveyor belt) so that they are arranged along the same spreading conveyor belt.

The invention also relates to a method for producing a bulk material mat with a spreading device of the type described or with a spreading apparatus of the type described (consisting of a plurality of spreading devices), wherein a flow of bulk material is selectively directed from the scattering chamber either only onto a first spreading region or only onto a second spreading region of the spreading head by means of a switching device arranged between the scattering chamber and the spreading head. The mode of operation of such a device is therefore likewise claimed.

In a preferred mode of operation, the bulk silo is selectively filled with different types of bulk material. This means, for example, different material types, such as fibers or wood chips, or different material compositions, such as fibers of different sizes or wood chips of different sizes. Depending on the bulk material contained in the bulk silo, the bulk silo is then selectively guided from the bulk silo by means of the switching device either only onto the first or only onto the second spreading region of the spreading head, so that the bulk material arrives on the spreading conveyor either via the first or via the second spreading region, wherein the two spreading regions are each optimally adapted to the respective bulk material. Optionally, it is possible to direct the material onto one of two scattering areas, which are designed for different orientation directions of the bulk material and/or for different sorting directions of the bulk material, with the same silo filling or the same material type, so that the material is oriented differently and/or sorted differently, depending on the selection of the scattering area.

In general, the desire to economically adapt to increased requirements and in particular flexibility in the wood material board industry is successfully achieved within the scope of the invention. The present invention may therefore respond to the need to provide a device that uses different materials into different layers in order to achieve corresponding characteristics and economy for a particular product. The response can be made fast and flexible in the sense of product diversification, so that different products can also be provided in smaller batches in an economical manner and as required, taking into account the increased competition. This can be achieved at low cost in terms of equipment technology.

Drawings

The invention will be elucidated in more detail below on the basis of the appended drawings showing only embodiments. In the drawings:

figure 1 shows a first embodiment of a scattering apparatus with two scattering devices (scatterers),

fig. 2 shows the solution according to fig. 1 according to a modified second embodiment, and

fig. 3 shows a third embodiment of the solution according to fig. 1.

Detailed Description

In the figures, a spreading installation is shown in each case, which has two spreading devices 1, also referred to as spreaders, arranged one behind the other in the transport direction T of a spreading conveyor 2. Each such scattering device 1 has a scattering bunker 3 and a scattering head 4 arranged below the scattering bunker 3 and above the scattering conveyor belt 2, wherein the scattering head 4 has a plurality of scattering rollers 5 arranged directly above the scattering conveyor belt 2, which scatter the scattering material directly onto the scattering conveyor belt 2, distributed in the transport direction T of the scattering conveyor belt 1. The bulk bunker 3 serves as a material buffer for receiving bulk material (for example fibers or wood chips) and discharging the bulk material onto the distribution head 4. For this purpose, the bulk silo is preferably designed as a dosing silo with a dosing unit 6, which in the exemplary embodiment is designed as a silo bottom strip. The bulk bunker 3 also has a discharge unit, which is only schematically illustrated and is designed, for example, as a discharge roller surface 7. A discharge shaft 8 is arranged between the bulk silo 3 and the scattering head 4, so that the material passes over the discharge roller face 7 of the bulk silo 3 and the discharge shaft 8 to the scattering head 4 and from there to the scattering conveyor belt 2, so that a bulk material mat is formed on the scattering conveyor belt 2. In the embodiment shown, the apparatus has two spreaders 1 in order to achieve a multi-layered structure of the bulk mat, that is to say, the two spreaders 1 are assigned to the same spreader conveyor 2.

According to the invention, the spreading head 4 of the spreader 1 now comprises at least two spreading

areas

4a, 4b arranged one behind the other with different roller geometries and/or different roller patterns. Between the bulk silo 3 and the spreading head 4, a switching device 10 is provided, with which a stream of bulk material can be selectively directed from the bulk silo 3 either only onto the first spreading region 4a of the spreading head 4 or only onto the second spreading region 4b of the spreading head, so that only one of the

bulk material regions

4a, 4b is selectively fed at all times by means of the switching device 10. In this way, it is successfully achieved that the spreader 1 is variably adapted to the desired circumstances, for example to the material used, to the desired material orientation direction and/or to the desired composition sorting (relative to the mat cross section).

Fig. 1 shows a first embodiment in which the switching device 10 has an adjustable guide element 11, which is designed as an adjustable switching flap 11, wherein the switching flap 11 can be pivoted about a pivot axis which is oriented parallel to the axis of the roller 5 of the dispensing head 4. It can be seen that by switching the switching flap 11 either the first spreading zone 4a or the second spreading zone 4b of the respective spreading head 4 can be fed.

In this way, it is possible to optimize the first distribution area 4a and the second distribution area 4b for different material types, so that, for example, the first distribution area 4a is optimized for fibers and the second distribution area 4b is optimized for wood chips or shavings. Now, in a preferred embodiment, the scattering bin 3 of the scattering device 1 is selectively filled with a first material type (e.g. fibers) or with a second material type (e.g. wood chips) or with different component sizes of the material, and then a scattering area is selected via the switching device 10, which is optimally adapted to the type of material provided in the bin 3. In this way, the spreader 1 can be variably adapted to different material types and thus also to different board types, so that different board types can be pressed with the same apparatus. In this case, it is schematically shown in this exemplary embodiment that different spreading rollers 5 can be used in the spreading

regions

4a or 4b, i.e. the first spreading region 4a or the second spreading region 4b can each be subdivided into further spreading regions. However, irrespective of the type of material used, the two different scattering areas can also be adapted to different scattering characteristics, so that the first scattering area 4a can be configured, for example, for a specific type of orientation (for example longitudinal or transverse orientation) and/or for different component sorting. In fig. 1, an embodiment is schematically shown, however, in which the first distribution area 4a is configured for component sorting of fibers that have not been sorted, in which the fines are arranged closer to the product surface and the coarser is arranged closer to the core of the plate. In contrast, the second scattering area 4b is optimized for wood chips, which, however, are likewise not oriented and in this case are not sorted either.

Fig. 2 shows a modified embodiment in which the switching device 10 comprises a roller device 12 having a plurality of switching rollers 13 which can be switched in their direction of rotation. In addition, in this embodiment, the switching flap 11 already mentioned in fig. 1 is also provided, however, in principle the switching device 10 can also be realized without a switching flap with just a switching roller. The switching roller 13 is shown schematically as being reversible. It is an acceleration roller with a reversible direction of rotation, so that the respective spreading

area

4a, 4b can be selected by selecting the direction of rotation, more precisely in the embodiment in combination with the switching flap 11.

Fig. 3 shows an embodiment in which, on the one hand, a switching device 10 having a switching roller 13 is provided, and additionally a plurality of adjustable guide elements 14 are provided above the switching roller 13, which form variable product constrictions in the blanking shaft 8. In this embodiment, the roller plane of the switching device 10 may have a distribution function in addition to the switching function. To this end, the distribution roller may be connected to the switching roller 13 (e.g. in one direction).

Furthermore, it is shown in fig. 1 to 3 that the switching device 10 can additionally have a fixed guide element 15, for example a wedge, which separates the two

distribution areas

4a, 4b from one another, so that overall it is ensured that in practice only one of the distribution areas is fed at all times.

The possibility already mentioned by way of example in connection with fig. 1 is to treat different materials with spreading

areas

4a, 4 b. Alternatively, it is possible to work with the same material type, for example with wood shavings (OSB shavings), which, however, should be sorted differently. Thus, for example, the first distribution area 4a can be configured for shavings and for longitudinal orientation, but for a particular first sorting direction in which coarse material is closer to the product surface and fine material is closer to the board core. The second distribution area 4b can likewise be configured for shavings and for longitudinal orientation, however with an opposite sort in which the fines are arranged closer to the product surface and the coarse material is arranged closer to the core of the plate. This can be realized exemplarily with the embodiment according to fig. 2.

Alternatively, it is also possible to work with the same material type, but with different material orientations. Thus, for example, the same material type (for example wood shavings for OSB panels) can be oriented transversely in the first distribution area 4a and longitudinally in the second distribution area 4 b. Alternatively or additionally, different sorting can also be achieved in the two scattering areas. Such a selection can be realized, for example, with the embodiment according to fig. 3.

Overall, very different embodiments can be realized, in which the scattering areas are designed for different material types and/or for different orientation directions and/or for different component sorting in different combinations.

Furthermore, only two spreaders 1 of such a device are schematically shown in the figures. However, it is also possible to provide further spreaders 1, for example one further spreader on the left and right, respectively. The illustrated spreaders are then provided, for example, for creating an intermediate or middle layer, and two spreaders provided to the left and right of the illustrated spreader are used for the cover layer or optionally also for additional intermediate layers. However, a series arrangement of a plurality of such spreaders is known from the prior art. In the context of the present invention, a single spreader is variably adapted to different product types according to the invention.

Claims

1. Method for producing a mat of bulk material on a spreading conveyor (2) in the manufacture of a board of wood material,

a scattering device (1) is provided, which has at least one scattering bin (3) and a scattering head (4) arranged below the scattering bin (3) and above the scattering conveyor belt (2),

the spreading head (4) has a plurality of spreading rollers (5) distributed in the transport direction (T) which spread the spread material onto the spreading conveyor belt (2),

the spreading head (4) comprises at least two spreading zones (4a, 4b) arranged one behind the other with different roller geometries and/or different roller operating modes,

between the bulk silo (3) and the spreading head (4) there is a switching device (10) with which the bulk material flow is selectively directed from the bulk silo (3) either only onto a first spreading region (4a) or only onto a second spreading region (4b) of the spreading head (4),

characterized in that the bulk silo (3) is selectively filled with different types of bulk material, and that depending on the bulk material contained in the bulk silo (3), the flow of bulk material is selectively directed from the bulk silo (3) either only onto a first spreading region (4a) or only onto a second spreading region (4b) of the spreading head (4) by means of the switching device (10).

2. Method according to claim 1, characterized in that a switching device (10) is used, which has at least one adjustable guide element (11).

3. Method according to claim 2, characterized in that the guide element (11) is configured as a switching flap.

4. Method according to claim 1, characterized in that a switching device (10) is used, which has at least one roller device (12) with a plurality of switching rollers (13) which can be switched in their direction of rotation.

5. Method according to claim 1, characterized in that a switching device (10) is used which has a plurality of adjustable guide elements (14) which form variable material constrictions.

6. Method according to claim 1, characterized in that a switching device (10) is used, which has at least one fixed guide element (15).

7. Method according to any one of claims 1 to 6, characterized in that a blanking shaft (8) is provided between the bulk bin (3) and the scattering head (4), the switching device (10) being provided at least partially within the blanking shaft (8).

8. The method according to any one of claims 1 to 6, characterized in that the two scattering areas (4a, 4b) are designed for different orientation directions of the bulk material.

9. The method according to any one of claims 1 to 6, characterized in that the two scattering areas (4a, 4b) are designed for different sorting directions of the bulk material relative to the mat cross section.

10. The method according to any one of claims 1 to 6, characterized in that the two scattering areas (4a, 4b) are designed for different bulk materials.

11. The method according to any one of claims 1 to 6, characterized in that two spreading devices (1) for producing a multi-layered bulk mat are used, which two spreading devices (1) are arranged one after the other in the transport direction (T) of the spreading conveyor (2).

12. The method according to any one of claims 1 to 6, characterized in that the bulk material is selectively directed onto one of the two scattering areas (4a, 4b) which are designed for different bulk materials or different types of bulk materials and/or for different orientation directions of the bulk material and/or for different sorting directions of the bulk material relative to the mat cross section.