WO2021156520A1

WO2021156520A1 - Wind distributing chamber and method for distributing and forming a free-flowing material on a forming belt

Info

Publication number: WO2021156520A1
Application number: PCT/EP2021/052990
Authority: WO
Inventors: Christoph DEMEL; Klaus Plutowsky; Daniel Schwartze
Original assignee: Dieffenbacher GmbH Maschinen- und Anlagenbau
Priority date: 2020-02-07
Filing date: 2021-02-08
Publication date: 2021-08-12
Also published as: CN115087529A; EP4100223A1; DE102020103233A1

Abstract

The invention relates to a wind distributing chamber and method for distributing and forming a free-flowing material (8) to form a material nonwoven (11) on an endlessly revolving forming belt (12) during the course of the production of material panels in a press, the wind distributing chamber (10) having a chamber (1) with a material feed (22) for introducing the material (8) into an airflow (13), a first chamber height (2a) being variable in a first region (I) of the chamber (1) by the distance between ceiling (12) and the forming belt (12), and the chamber height being variable in a further region (II, II, IV) in the flow direction (7). A wall (4) that continuously reduces the chamber height (2b) is arranged below the ceiling (23) in the second region (II) and a wall (5) continuously increasing the chamber height is arranged in the third region (III).

Description

WIND SPREADING CHAMBER AND METHOD OF SPREADING AND SHAPING

OF A GRAVELING MATERIAL ON A MOLDING TAPE

The invention relates to a wind scattering chamber for scattering and shaping a pourable material into a single or multi-layer material fleece on an endlessly revolving shaping belt, preferably in the course of the production of material panels in a press according to the preamble of claim 1.

The invention also relates to a method for scattering and shaping a pourable material into a single or multi-layer material fleece on an endlessly revolving shaping belt, preferably in the course of the production of material panels in a press according to the preamble of claim 40.

In the production of material panels, natural substances such as annual plants, lignified shrub plants, trees or the like are predominantly shredded, dried, mixed with a binding agent if necessary, scattered to form a material fleece and compacted in a press to form a material panel. The use of plastics or other materials is also provided in order to obtain flat strands of material during continuous production that can be divided. The intermittent processing of the material fleeces is also conceivable; they can, for example, be divided up before pressing. Today, in fiber or chipboard production, natural substances are increasingly being substituted with recycled material in order to minimize the need for fresh wood. It is common to combine wind scattering chambers with other scattering devices in order to achieve various layer structures.

DE 198 35419 A1 has disclosed an example of a device and a method for air classification. The prior art described therein sufficiently outlines any discussion of the prior art of the present invention. From the above disclosure it is known to use various techniques for influencing the air flow, in particular wind screens and suction devices. The windform technique places value on depositing the material evenly. Eddy currents in the air flow, but also separation phenomena in the air flow on the walls, should be avoided, as these interfere with the basis weight accuracy. Today's industry demands, in addition to a high basis weight accuracy, an ever greater reduction in the natural raw material required and, as a result, the partial or complete substitution of the raw material by recycling material. This is partly also a government mandate in various countries. All of these requirements lead to the use of very long wind scattering chambers.

One possibility for reducing the overall length of a wind scattering chamber would be to arrange more sieves or flow obstacles in the wind scattering chamber in order to accelerate the deposition of the material. Such an arrangement of many sieves is undesirable because the energy expended in operation for generating the ventilation or the air flow is unnecessarily destroyed without achieving sufficiently good advantageous effects. This usually also results in disturbing accumulations or clusters of material, which after hitting the forming belt produce noticeable entries in the mat and the later product material plate compared to the neighboring scattering.

With DE 102006038 183 A1 and DE 102009007 944 A1, wind scattering chambers of their own type have also become known.

The present invention is based in particular on DE 102009007944 A1. In this disclosure, a wind scattering chamber was presented which, due to different ceiling heights along the air flow, can set different room volumes in the wind scattering chamber. For this purpose, the ceiling is designed as a variable cover which has variably adjustable ceiling areas. It is specified that the ceiling heights in the various chamber zones should be at a constant distance from the molding belt, and thus be aligned parallel to the molding belt. These can then, for example, be vertically adjustable in terms of their distance from the forming belt. Between the individual horizontal planes, inclined and / or curved transitions can be provided along the flow direction, which connect the horizontal planes. In a detailed embodiment, a variant of the wind scattering chamber is shown, which along the flow direction several, in their Contains height differently arranged, horizontal ceiling elements, which are connected accordingly. Such an arrangement of horizontal and height-adjustable ceiling elements has basically proven itself in practice, but still leaves room for improvement.

The invention is based on the object of creating a wind scattering chamber and a method for scattering and shaping a free-flowing material into a single or multi-layer material fleece on an endlessly rotating shaping belt which, in a short and concise length, meets the demands made by industry for high quality and the lowest possible raw material requirements.

The invention is based on a wind scattering chamber for scattering and shaping a free-flowing material into a single or multi-layer material fleece on an endlessly revolving molding belt in the course of the production of material panels in a press, the wind scattering chamber being a chamber with a material supply for introducing the material into has an air stream, the air stream entering the chamber via an inlet opening and preferably discharged at the other end of the chamber via an outlet opening, with a first room height in a first area of the chamber due to the distance between the ceiling and the molding belt and in Direction of flow in a further area, the room height is designed to be changeable.

The task for the wind scattering chamber is achieved in that in the second area below the ceiling there is a wall which continuously reduces the room height and in the third area a wall which continuously increases the room height.

In analogy to the mathematical or geometrical function, the invention understands by continuous that the height of the room along the wall continuously decreases or increases in the direction of flow.

A chamber has a ceiling, side walls along the direction of flow and front and rear transverse to the direction of flow and a floor. The bottom can also be formed by the molding tape if a more open construction is chosen. The room height is defined as the distance between the material-receiving molding tape and the ceiling or the wall of the chamber. According to the present invention, the flat ceiling is essentially covered with a wall that has a predetermined geometric shape and predominantly a lower height of the chamber, between the molding band and wall, than in the first area of the chamber, in which the air flow and the material into the Chamber enters.

The wall transversely to the air flow or the shaping belt is preferably flat or straight, but can also be bent completely or only on the outer sides, i.e. on the side surfaces of the chamber, depending on the properties. This can be useful for adapting the flow conditions at the wall / side wall transition.

In a particularly preferred embodiment, the chamber has exactly three or four of the named areas. In order to enable the areas to be delimited here, as in the other exemplary embodiments, it can be stated that the reversal point, thus the lowest point of the wall, defines the boundary between the second and third area. The transition between the fourth and third area is when the rise of the wall ends in the third area and merges into a fourth area of a wall or the ceiling that is arranged parallel to the molding strip. If the rise in the wall continues until the air flow ends, the chamber only has three areas.

The transition between the first and the second area is at the point where the wall begins to decrease in height from the ceiling. In a special variant, the wall begins after the filling opening for the material in the chamber. The first area would then only be the filling opening itself, the room height then corresponds to the distance from the molding belt to the filling opening, or the ceiling height.

A particular advantage of the invention is that the possibility of adjusting the walls in accordance with the teaching of the invention means that the operator or supplier of the wind scattering chamber is now able to adjust the length of the various areas depending on the intended use. In In a simple manner, the reversal point in the chamber can be adjusted as required in terms of the distance from the forming belt, but also in terms of its distance from the entry of the air flow into the chamber and adapted to requirements.

The invention has also surprisingly found that the previous technical effort in the wind scattering chambers for a homogeneous and smooth transition of the particle size in a layer to be scattered does not have as great an effect on the quality of the plate as previously assumed. It is entirely possible to divide the wind scattering chamber into areas of different heights, with predominantly the coarse fractions being deposited in the flow direction in a first deposit area and the comparatively fine particles lying in a relaxed air flow in a second chamber area.

Fast and powerful air currents should therefore be avoided in the direction of flow in the rear area through the expansion of the available space. For this purpose, after the room height has been narrowed, the room height is expanded / increased again in order to give the fine material the opportunity to trickle onto the forming belt from the slowing air flow. A stepped classification is therefore particularly preferred, which is caused by the differences in the flow velocities. This difference can be supported by a flow obstacle, especially in the area of the transition between the different heights of the room.

The invention also has the possibility of reducing the overall length of the wind scattering chamber, with as free a flow as possible and preferably by dispensing with or reducing the flow resistances (sieves) that have been customary up to now. For this purpose, flow vectors are used with the constant reduction of the room height in order to strengthen the classification, in particular when the wall is designed in the form of drops, which will be described in detail later. At the same time, the performance of the fan can be reduced and / or the throughput rate per unit of time can be increased, in particular with the same or even improved quality.

The wall for changing the room height can be made of sheet metal or a plastic, preferably made of a less adhesive material, for example antistatic or slightly adhesive for binders, so that the material used for the material plate does not stick there. Also the use of natural wood or Material plates is conceivable. The wall particularly preferably consists of elastic or flexible elements, which are thus adjustable, but most preferably have sufficient resistance or rigidity in order not to be deformed or caused to vibrate by the air flow during operation. In an exemplary use, a conveyor belt or conveyor belt would be conceivable, which is suspended from the ceiling in the direction of flow at the front and rear.

It should also be noted that the wall or the ceiling should be arranged over the entire width of the chamber. The wall can particularly preferably have a convex or concave shape over the width in order to do justice to the flow conditions or the friction on the side walls.

According to the invention, a constant change in the height of the room means that no horizontal / horizontal holding line for the wall, in particular with respect to the molding band, should be introduced in this area.

In a special embodiment, it can be conceivable that instead of the reversal point, the transition from a falling to a rising room height, a preferably horizontal holding line is arranged at which the room height does not change or only changes slightly. This route forms a transition between the areas. This transition can prevent disruptive influences from being "carried along" from a previous area to the following area. Disruptive influences are fluidic disadvantages such as eddies, different vectors in the speed or orientation of the air flows. The inclination of the section preferably does not exceed 25 ° with respect to the forming belt, the inclination is particularly preferably less than 12.5 °, most preferably less than 5 °.

In a further preferred embodiment, the section or the area around the reversal point is shaped as a downwardly directed arrowhead, the reversal point forming the tip and inclined sections in or opposite to the direction of flow being arranged opposite the forming belt.

The air flow is arranged in the region of the chamber essentially parallel to the forming belt. This is intended to mean that the air flow along the Forming belt is guided, changes in the height of the room still lead to the air flow being guided along the forming belt, even if individual vectorial differences in the air proportions within the air flow may be present, for example if the height of the room is reduced. The air flow can be guided parallel to the forming belt in the entry area, but angled air flows within the meaning of the invention are also conceivable, in particular in order to optimize the material input or the material distribution in the air flow. It can thus be assumed that in the area where the air flow is introduced into the chamber, if baffles, nozzles and / or registers are arranged here, they are not necessarily designed in parallel.

Further cumulative or alternative additional features are shown below which, together, improve the solution to the task:

Preferably straight or curved walls can be arranged in the flow direction to change the height of the room, as long as the solution or the teaching of the invention is fulfilled.

Furthermore, a screening device, preferably for the coarser portions of the material, can preferably be arranged in the first area or in the following areas.

Furthermore, at least one, preferably two, most preferably three or more sieve grids are preferably arranged as the sieve device in the air flow. Cumulatively or alternatively, a coarse screen and / or a roller bed composed of coaxially arranged spreading rollers can be arranged, in particular in order to remove oversizes from the material and remove them from the manufacturing process.

Alternatively or cumulatively, the outlet opening or at least one further outlet opening on the ceiling or the wall of the chamber can be arranged in the fourth area. In particular, it is advantageous in the fourth area if the air flow is removed from the chamber in the upper area. In a possible alternative, this outlet opening can be arranged in the fourth area at the top of the ceiling.

It is also possible to have a further outlet opening at the transition between the third and fourth areas to be arranged on the wall or ceiling in order to partially divert the air flow out of the chamber without vortices.

With regard to the second and / or third area, a wall reducing the room height along a first straight line or a second curvature and, after a reversal point in a third area, a wall increasing the room height along a second straight line or second curvature can be arranged in the second area.

Particularly preferably, at least the curvature of the wall in a sectional side view of the chamber has essentially the geometrical outside of one half of a drop cut along its plane of symmetry. This is preferably mapped from a hemispherical shape to a pointed end or vice versa in the chamber. The invention understands the drop shape to be a ball tapering to a point on one side; this occurs physically when a drop is about to be detached, that is, during the formation of the drop. However, the wall preferably does not follow the teardrop shape over the width of the molding belt, but rather is arranged flat or parallel to the molding belt.

In a first alternative, a radius of the first curvature of the wall in the first area can be made smaller than the radius of the second curvature, with a ratio of the first radius to the second radius of 1 to 2, preferably of 1 to 5 and very particularly preferably of 1 to 10, can be used.

In a second alternative, the radius of the first curvature of the wall in the first area can be made larger than the radius of the second curvature, with a ratio of the first radius to the second radius of 2 to 1, preferably of 5 to 1 and very particularly preferably of 10 to 1, can be used.

The radii of the curvature in the second or third region are particularly preferably designed to decrease and / or increase along the air flow. This benefits the evenness of the air flow and avoids turbulence. In the case of geometries of this type, too, the wall is preferably designed to be essentially parallel transversely to the molding strip. Alternatively or cumulatively, the geometric shape of the wall for adjusting the height of the room can be arranged invariably. This is intended to indicate a fixed geometry. This is particularly advantageous when the geometric shape of the wall is formed based on a simulation calculation of the flow behavior of the air flow and is thus already optimized. Differentiated settings during operation for optimization should then not be necessary. This is particularly advantageous if the materials or material mixtures used for the material fleece do not experience any changes in production that have an influence.

Possibilities for adjusting the wall (s) can be preferred if the material throughput per unit of time is intended to be changed in an industrial-technical application.

Mixtures of materials can for example consist of fibers, shavings, chips from "fresh" wood, which means that these particles are on the one hand from machining processes directly for panel production or as offcuts from wood production (sawmills, chippers, chippers) Untreated wood, originated, and mixed with waste wood from recycling on the other hand.

The room height in the fourth area of the chamber, if present, is preferably lower than in the first area. This also applies to a wall if it extends into the fourth area.

After optimization or after tests, it may be found that a route could be arranged at the reversal point in which the room height does not change or only changes slightly. This route forms a transition between the areas. This transition can prevent disruptive influences from being "carried along" from a previous area to the following area. Disruptive influences are fluidic disadvantages such as eddies, different vectors in the speed or orientation of the air currents. The inclination of the section preferably does not exceed 25 ° with respect to the forming belt, the inclination is particularly preferably less than 12.5 °, most preferably less than 5 °. In a further preferred embodiment, the section is shaped as a downwardly directed arrowhead, the reversal point forming the tip and sections inclined in or against the direction of flow being arranged opposite the forming belt.

In a preferred alternative, the wall in the second and third area can be designed symmetrically with respect to a plane of symmetry which is perpendicular to the molding strip and which passes through the reversal point. In addition to the possibility of using the same components to reduce production costs, there are similar compression and relaxation behavior of the air flow.

In a preferred further alternative, the room height can be reduced along a negative gradient in the second area in the flow direction and the room height can be increased along a positive gradient in the third area in the flow direction. This serves, among other things, to avoid turbulence.

To improve the teaching of the invention, a flow obstacle can be arranged between the forming belt and the wall in the second, third area and / or at the level of the reversal point. This enables the material to be deposited more quickly and can help to shorten the overall length of the wind scattering chamber.

The flow obstacle can preferably be designed as a grid, rods and / or a rotating roller. A grid, a sieve or a rod arrangement can preferably be designed to be horizontally and / or vertically variable in its length or in its size. The flow obstacle can begin directly, or as close as possible, above the material on the molding belt and extend to the wall, or there are spaces between the molding belt and the wall. For example, it can be intended to arrange a free area in the area between the wall and the flow obstacle so as not to slow down the flow too abruptly. In this respect, it would be advantageous if the flow obstacle is arranged at a distance from the wall and / or from the molding band / material fleece.

It can be advantageous if the flow obstacle in its position and / or Position in the chamber would be arranged adjustable and the adjustability would preferably be realized via controllable adjusting means.

In a further alternative or cumulative embodiment, the walls in the second area and third area, preferably together with the wall of the fourth area, can be connected to one another in an articulated manner or formed in one piece. The joints can have devices for specifying the maximum angle of rotation or a predetermined angular range. This is particularly advantageous when adjusting means are arranged on the suspension of the walls or on the walls themselves.

In another particularly preferred embodiment, the walls, in a side view of the chambers, have the outer shape of half an idealized drop (in side view), cut along the line of symmetry of the drop. Thus, instead of the circle in the single drawing, half a teardrop shape of the walls would be recognizable. The sectional plane of the figure is perpendicular to the plane of symmetry of the drop, which is arranged parallel to the ceiling of the chamber. The tip of the drop should be aligned either in or against the air flow.

The walls can preferably be designed as a flexible belt or a belt, preferably made of a material similar to or for a conveyor belt. Rubber compounds, with or without reinforcements, can be used.

Preferably, there should be an inherent rigidity that offers sufficient resistance to the air flow without allowing any appreciable deformation. A flexible belt or band offers sufficient flexibility with a conceivable adjustment or adjustment of the walls, usually in connection with good antistatic properties. They also offer the option of compensating for changes in the chamber geometry due to temperature fluctuations during operation.

In order to be able to optimally adjust the properties of the walls to the operation, it can be provided within the wall and / or along the ceiling-side surface of the wall, preferably adjustable or adjustable, stiffening elements to be arranged. Can be used here in conjunction with adjustment elements or other adjustment means, the inherent rigidity of a wall can be increased and / or adjusted. These can be set up statically before commissioning or designed to be adjustable dynamically during operation.

It can preferably be provided, in particular for the formation of a teardrop shape, that the rear part of the wall, viewed in the direction of flow, is made more rigid than the part of the walls located in front of it. The rear part would therefore be oriented steeply in the direction of the molding band if it was suspended from the ceiling and would only begin to form a curve towards the end of the stiffening (against the direction of flow). This almost automatically results in a teardrop shape, which can be particularly preferably supported by the connections between the ends of the walls or with the ceiling as well as spacer or stiffening elements.

It can also be advantageous if the walls have stiffeners transversely to the direction of flow, preferably over the entire width, in the middle and / or in the vicinity or in the region of the side walls. In this way, pressure increases due to the air flow and / or the material inside the chamber at the transitions between the side wall / walls can be counteracted.

In addition, the invention understands transversely to the forming belt the orientation transversely to the transport direction of the forming belt. The term about the width of the molding belt can also be understood in a similar manner, since the molding belt is arranged circumferentially along its length and has a width. The width of the molding tape essentially corresponds to the width of the chamber, with marginal deviations being conceivable depending on the sealing principle.

Alternatively or cumulatively, it can be provided that sealing elements, preferably sealing lips on the walls, are arranged between the walls and the side walls of the chamber. This avoids contamination of the area between the walls and the ceiling. It also improves the adjustment properties of the walls if no material can be introduced here.

Another special embodiment would be the arrangement of a fixed point at least one side wall and / or on one of the wall, preferably an adjustable fixed point. For example, a specific shape can be specified or influenced by such a fixed point if this cannot be achieved by the wall itself. Such a fixed point can also be suitable for influencing the shape of the walls when they are moved by adjusting drives.

In particular, it can be provided that the reversal point, as the smallest room height, is fixed while the shape of the walls, for example a one-piece or articulated band, is moved on its suspensions and thus changes the gradient of the rising and falling room height. This fixed point can also be implemented from the outside by insertable bolts which are inserted or removed from predetermined closable bores in the chamber. These can also be automated and / or adjustable in height and position along the chamber in link grooves.

Alternatively or cumulatively, fixed connections and / or adjusting elements for influencing the geometry of the wall can be arranged in operative connection with the wall and the ceiling. Here, slides or similar machine elements can lift the walls at predetermined locations through the ceiling or press them down. There is the possibility of creating complex geometries of the room height. This is one of the advantageous possibilities to provide a separate wall within the chamber or below a ceiling, despite the increased structural effort.

In the sense of a continuous wall, a one-piece wall can be arranged over several areas, i.e. the beginning of the wall in the second area and the end of the wall in the third or fourth area, with only the beginning and the end preferably being arranged on the ceiling.

In particular with this embodiment, but not limited to it, an adjustment of the position of the wall in the chamber and / or the geometry of the wall or the beginning and / or the end of the wall can be adjusted with a displacement device, preferably parallel to the ceiling. For this purpose, a simple slide, preferably parallel to the forming belt, can be arranged on the ceiling, the at least one suspension of the wall moves. However, this slide can also connect two walls to one another and move them against one another in order to adjust the geometry and / or the position or the suspension of the walls.

Provision can be made for one of the walls to vibrate with an exciter. This can be done for cleaning purposes but also to support an adjustment of the walls or to reduce stresses in the walls.

In the flow direction, the room heights of the second area and the third area are preferably the same only at the reversal point.

In a particular embodiment, in the area of the reversal point on the adjacent part of the wall, a substantially horizontal holding line can be arranged, on which the room height does not change or only changes slightly. The angle of inclination of the holding line can be designed to be less than 25 °, particularly preferably less than 12.5 °, most preferably less than 5 ° with respect to the shaping belt.

More specifically, the holding line, starting from the reversal point, can extend into both adjacent areas of the walls and particularly preferably be shaped as a downward arrowhead, the reversal point forming the tip and inclined sections in or against the flow direction being arranged opposite the forming belt.

These previous embodiments can be technologically necessary to improve the turbulence problem at or at the reversal point and can be implemented in particular by arranging a joint at the reversal point between the two walls, the joint particularly preferably having inherent rigidity or a predetermined angle for setting the tip. Specific reinforcements on the otherwise flexible, adjustable wall can also be used to create special geometries.

The invention understands the term flexible wall in such a way that the geometry of the wall can be influenced by adjusting or other means. It is there preferably it is not provided that the air flow with the material within the chamber should cause a change in the geometry during operation.

As a further measure for setting the chamber and the interaction with the walls, the number, arrangement, orientation, size and permeability of all sieves, for example the sieve device, the sieve, in the chamber can be designed to be variably adaptable, preferably via actuators.

For the design of a fixed geometry or adjustability, latching elements, preferably magnets and / or areas protruding from the walls / side walls, can be arranged laterally on the walls, which are most preferably in operative connection with corresponding counter bearings on the side walls / walls or in Can be brought into operative connection during an adjustment of the geometry of the walls. In order to increase the stability and the steadfastness against the air flow of the transition wall / side wall, these measures are indicated under certain circumstances. These means also seem to make sense for the reproducibility of adjustable wall geometries.

Grooves, blind bores, protrusions, magnets and / or other machine elements can be arranged on the inside on or in the side walls, which with corresponding counter bearings of the walls exercise a locking or holding function. The reverse also applies accordingly. In order to increase the stability and the steadfastness against the air flow of the transition wall / side wall, these measures may be useful. In the event of an operational change in the geometry of the walls, predetermined latching positions by means of interventions or markings on the side walls can be useful. This is used in particular for the reproducibility of settings for the geometry of the walls in specific production modes or in order to be able to return precisely to previous settings.

The above individual features / features can also be implemented in terms of process technology, in particular in connection with changes in the wall geometry that can be carried out using process technology in differentiated production modes. A corresponding method for scattering and shaping a free-flowing material into a single or multi-layer material fleece on an endlessly revolving molding belt in the course of the production of material panels in a press is based on a known wind scattering chamber, which has a chamber with a material supply for introducing material into has an air stream, the air stream entering the chamber in a first area via an inlet opening and discharged at the other end of the chamber via an outlet opening, a room height is formed in the distance between the ceiling of the chamber and the molding belt.

The object for a method is achieved in that the room height is reduced in a second area in the flow direction and the room height is continuously increased in a third area through the wall between the ceiling and the molding belt.

In the second or third area, at the boundary between the two areas, the air flow is particularly preferably guided through a flow obstacle, for example a sieve, in order to deposit the coarse portions of the material more quickly on the forming belt.

In addition, the features and advantages shown in connection with the wind scattering chamber according to the invention and the method according to the invention and their respective advantageous configurations apply mutatis mutandis and vice versa.

The individual features and advantages, separated in paragraphs above, can be exchanged or combined with one another as required, whereby further advantageous effects can arise that go beyond the sum of the individual effects.

Further advantages, features and details of the invention emerge from the following description, in which an exemplary embodiment of the invention is explained in more detail with reference to the drawing. The person skilled in the art will expediently consider the features disclosed in combination in the drawing, the description and the claims also individually and combine them into meaningful further combinations.

The drawing shows schematically a wind scattering chamber for producing a material fleece on a forming belt in the course of the production of material panels, a wall for changing the height of the room being arranged in the wind scattering chamber.

It can be seen from the drawing that material 8 is introduced into chamber 1 of wind scattering chamber 10 via a material supply 22, moved by an air flow 13 opposite to the conveying direction of the forming belt 12 and onto the chamber 1 in areas I, II, III, IV Shaping tape 12 is deposited as material fleece 11. In the present example, a roller for loosening up the material is arranged above the air flow 13. The air flow 13 arriving through the air supply 24 enters the chamber 1 through the inlet opening 14 and moves the material 8 in the flow direction 7 of the air flow 13. The chamber 1 is divided into four areas I, II, III, IV and the air flow 13 flows through them accordingly consecutive numbering. In the first area I, the ceiling 23 forms a room height 2a with the molding band 12 delimiting the chamber 1 at the bottom.

Together with the air flow, the material flows through a sieve device 17 in which at least one sieve grid 18 is arranged. Preferably, as shown here, a coarse screen 19 can be arranged essentially parallel to the forming belt, which separates oversized material from the process through its thermal connection with a discharge device 25. Alternatively, instead of the coarse screen 17, a roller screen formed from coaxial rollers can also be arranged in order to homogenize the incoming material 8.

At the transition to the second area II, the room height 2a changes due to the arranged wall 4 with the room height 2b. The wall 4 can represent different geometries which have the lowest room height 2b in the flow direction 7 at the end of the area II. The reversal point 9 would also be arranged there, which marks the transition to the third area III, at which the wall 5 is arranged in such a way that the room height 2c increases again in the direction of the flow direction 7. The walls 4, 56 can have different geometries, with the first wall 4 having a first radius 20 and the second wall 5 having a second radius 21 in the present exemplary embodiment. These radii can be designed the same but also different.

At the end of the third area III, the area IV is arranged with the room height 2d, which has an outlet opening 15 at the end, from which the air flow 13 can be removed from the chamber 1 again. Alternatively, the outlet opening 15 can be arranged on the ceiling 23 or, if present, on a wall 6 located in this area. The wall 6 or the ceiling 23 can form a lower room height 2d than the room height 2a in the first area I.

An additional or single outlet opening 16 is particularly preferably arranged at the transition between the third area III and the fourth area IV.

To support the Venturi constriction of the chamber 1, a flow obstacle 3 can be arranged in the second area II or in the third area III, which brakes the air flow 13 or the material 8 in the air flow 13. Due to the flow obstacle 3, in particular the comparatively larger particles of the material 8 that are still present are slowed down and moved in the direction of the forming belt 12.

In the present example, a cover layer is scattered, whereby the finest particles of the material 8 first come to lie on the forming belt 12, which is moved against the air flow 13 or the flow direction 7, and thus form a sub-layer of a multi-layer material fleece 11 when in the running direction of the Forming belt 12 still further spreading machines and / or wind spreading chambers are arranged. The subsequent wind scattering chamber will then be arranged the wrong way round in order to deposit the smallest particles on the surface of the material fleece.

A preferred teardrop shape of the walls 4 and 5 was not shown in the drawing. However, it was indicated by way of example that the wall 5 has a preferably approximately straight reinforcement in the rear area, the wall 5 is drawn thicker here. This can be useful in the case of a flexible material of the wall in order to preferably depict geometries of the walls, for example in the case of wall 5 a stronger gradient of the increase in the room height 2c compared to the gradient of the decrease in the room height 2b. In particular, the suspension of the wall 4 on the ceiling 23 could be displaced against the air flow 13 by means of a slide, symbolically represented by a double arrow. As a result of the stiffening, the curvature along the wall 4 will flatten out, while the curvature 5 would change less strongly due to the stretching of the distance between the suspension points of the walls 4, 5.

LIST OF REFERENCE SYMBOLS P1610WQ:

I chamber

2a ceiling height

2b room height

2c room height

2d room height

3 flow obstruction

4 wall

5 wall

6 wall

7 Direction of flow

8 material

9 turning point

10 wind scattering chamber

I I material fleece

12 molding tape

13 air flow

14 Entrance opening

15 outlet opening

16 outlet opening (second)

17 Sieve device

18 sieve grids

19 coarse sieve

20 radius (first)

21 radius (second)

22 Material supply

23 ceiling

24 air supply

25 discharge device

I area

II area

III area

IV area

Claims

1. Wind scattering chamber for scattering and shaping a pourable material (8) into a single or multi-layer material fleece (11) on an endlessly rotating molding belt (12), preferably in the course of the production of material panels in a press, the wind scattering chamber (10) having a chamber (1) with a material supply (22) for introducing the material (8) into an air stream (13), the air stream (13) entering the chamber (1) via an inlet opening (14) and preferably at the other end of the Chamber (1) is discharged via an outlet opening (15), with a first room height (2a) and in Flow direction (7) in a further area (II, III) the room height (2b, 2c) is designed to be changeable, characterized in that in the second area (II) below the ceiling (23) a wall which steadily reduces the room height (2b) (4) and in the third area (III) a d The wall (5) is arranged to increase the height of the room.

2. Wind scattering chamber according to the preceding claim, characterized in that a screening device (17) for the coarser portions of the material (8) is arranged in the first area (I).

3. Wind scattering chamber according to one of the preceding claims, characterized in that the screening device (17) is at least one, preferably two, most preferably three or more screen grids (18) in the air stream (13) and / or a coarse screen (19) and / or a roller bed is arranged from coaxially arranged spreading rollers.

4. Wind scattering chamber according to one of the preceding claims, characterized in that the outlet opening (15) is arranged in the fourth region (IV) or one, preferably further, outlet opening (16) on the ceiling (23) or the wall (6) of the chamber (1) is arranged.

5. Wind scattering chamber according to one of the preceding claims, characterized in that in the second area (II) a wall (4) reducing the room height (2b) along a first straight line or a second curvature and after a reversal point (9) in a third area ( III) a wall (5) which increases the room height (2c) along a second straight line or second curvature is arranged.

6. Wind scattering chamber according to one of the preceding claims, characterized in that as the curvature of the wall (4, 5) the geometric outside of a drop is partially arranged along the axis of symmetry, which is preferably designed from a hemispherical shape to a pointed end, preferably The walls (4, 5) are essentially flat over the width of the chamber (1).

7. Wind scattering chamber according to one of the preceding claims 1 to 5, characterized in that the radius (20) of the first curvature of the wall (4) is designed to be smaller than the radius (21) of the second curvature of the second wall (5), preferably a ratio of the first radius (20) to the second radius (21) of 1 to 2, preferably of 1 to 5 and very particularly preferably of 1 to 10, is arranged.

8. Wind scattering chamber according to one of the preceding claims 1 to 5, characterized in that the radius (20) of the first curvature of the wall (4) is designed to be greater than the radius (21) of the second curvature of the second wall (5), preferably a ratio of the first radius (20) to the second radius (21) of 2 to 1, preferably of 5 to 1 and very particularly preferably of 10 to 1, is arranged.

9. Wind scattering chamber according to one of the preceding claims, characterized in that the radii (20, 21) of the curvature in the second area (II) or in the third area (III) are arranged from and / or increasing along the air flow.

10. Wind scattering chamber according to one of the preceding claims, characterized characterized in that the geometric shape of the wall (4, 5) for setting the room height (2b, 2c) is arranged invariably.

11. Wind scattering chamber according to one of the preceding claims, characterized in that the geometric shape of the wall is based on a simulation calculation of the flow behavior of the air flow and is preferably arranged statically.

12. Wind scattering chamber according to one of the preceding claims, characterized in that the room height (2d) in the fourth area (IV) of the chamber (1) is lower than in the first area (I) and / or the wall (6) extends into the fourth area (IV) extends.

13. Wind scattering chamber according to one of the preceding claims, characterized in that a section is arranged at the reversal point (9) in which the room height does not change or changes only slightly.

14. Wind scattering chamber according to one of the preceding claims, characterized in that the wall in the second area (II) and in the third area (III) is designed symmetrically with respect to a plane of symmetry which is perpendicular to the forming belt and which passes through the reversal point.

15. Wind scattering chamber according to one of the preceding claims, characterized in that in the second area (II) in the flow direction (7) the room height (2b) is reduced along a negative gradient and in the third area (III) in the flow direction (7) the room height (2c ) enlarged along a positive gradient.

16. Wind scattering chamber according to one of the preceding claims, characterized in that in the second area (II), in the third area (III) and / or substantially at the level of the reversal point (9), a flow obstacle (3) between the forming belt (12) and the wall (5, 6) is arranged.

17. Wind scattering chamber according to one of the preceding claims, characterized characterized in that a grid, bars and / or a rotating roller is arranged as a flow obstacle (3).

18. Wind scattering chamber according to one of the preceding claims, characterized in that the flow obstacle (3) is arranged at a distance from the wall (4, 5) and / or from the forming belt (12) and is preferably designed to be variable in length

19. Wind scattering chamber according to one of the preceding claims, characterized in that the flow obstacle (3) is adjustable in its position and / or location, in particular in its alignment, in the chamber (1) and preferably the adjustability is carried out via controllable adjusting means.

20. Wind scattering chamber according to one of the preceding claims, characterized in that the walls (4, 5) in the second area (II) and third area (III), preferably together with the wall (6) of the fourth area (IV), are articulated to one another and / or are integrally formed.

21. Wind scattering chamber according to one of the preceding claims, characterized in that the walls (4, 5) in side view depict the outer shape of a half drop, cut along the symmetry line of the drop, the symmetry line of the drop being parallel to the ceiling (23) of the Chamber (1) is arranged and preferably the tip of the drop is aligned against the air flow (13).

22. Wind scattering chamber according to one of the preceding claims, characterized in that a flexible belt or a belt, similar to a conveyor belt, is arranged as the walls (4, 5, 6), preferably with an inherent rigidity that of the air flow (13) sufficient resistance without a Exhibits deformation.

23. Wind scattering chamber according to one of the preceding claims, characterized in that within the wall (4, 5, 6) and / or along the ceiling-side surface of the wall (4, 5, 6), preferably adjustable or adjustable, stiffening elements are arranged.

24. Wind scattering chamber according to one of the preceding claims, characterized in that to form a teardrop shape of the walls (4, 5,

6), the rear part of the wall (5, 6) viewed in the flow direction 13, is designed to be more rigid than the first part of the walls (4, 5).

25. Wind scattering chamber according to one of the preceding claims, characterized in that the walls (4, 5, 6) have reinforcements transversely to the direction of flow (7), preferably in the region of the side walls of the chamber (1).

26. Wind scattering chamber according to one of the preceding claims, characterized in that sealing elements, preferably sealing lips on the walls (4, 5, 6), are arranged between the walls (4, 5, 6) and the side walls of the chamber (1).

27. Wind scattering chamber according to one of the preceding claims, characterized in that a fixed point in operative connection with the side walls, preferably an adjustable fixed point, is arranged at least on the side wall and / or on one wall (4, 5, 6).

28. Wind scattering chamber according to one of the preceding claims, characterized in that fixed connections and / or adjusting elements for influencing the geometry of the wall (4, 5, 6) in operative connection with the wall (4, 5, 6) and the ceiling (23) are arranged.

29. Wind scattering chamber according to one of the preceding claims, characterized in that with a one-piece wall (4, 5, 6) over several areas (II, III, IV) the beginning of the wall (4) in the second area (II) and the end the wall (5, 6) is arranged in the third area (III) or fourth area (IV) in each case on the ceiling (23).

30. Wind scattering chamber according to one of the preceding claims, characterized characterized in that to adjust the position of the wall (4, 5, 6) in the chamber (1) and / or the geometry of the wall (4, 5, 6) the beginning and / or the end of the wall (4, 5, 6) is operatively connected to a displacement device, preferably parallel to the ceiling (23).

31. Wind scattering chamber according to one of the preceding claims, characterized in that at least one means for excitation is arranged to excite the wall (4, 5, 6) with vibrations.

32. Wind scattering chamber according to one of the preceding claims, characterized in that the room heights (2b, 2c) of the second area (II) and the third area (III) are the same in the flow direction (7) only at the reversal point (9).

33. Wind scattering chamber according to one of the preceding claims, characterized in that in the region of the reversal point (9) on the wall (4, 5) a substantially horizontal holding line is arranged, on which the room height (2b, 2c) is not or only slightly changed,

34. Wind scattering chamber according to one of the preceding claims, characterized in that the angle of inclination of the holding line is less than 25 °, particularly preferably less than 12.5 °, most preferably less than 5 ° with respect to the forming belt.

35. Wind scattering chamber according to one of the preceding claims, characterized in that the stop line, starting from the reversal point, extends into both adjacent areas of the walls (4, 5) and is particularly preferably shaped as a downward arrowhead, the reversal point (9) forms the tip and sections inclined in or against the direction of flow are arranged relative to the forming belt (12).

36. Wind scattering chamber according to one of the preceding claims, characterized in that the number, arrangement, orientation, size and permeability of all sieves, sieve device (17), sieve (3), in the chamber (1) are designed to be variably adaptable, preferably via actuators.

37. Wind scattering chamber according to one of the preceding claims, characterized in that on the walls (4, 5, 6) laterally locking elements, preferably magnets and / or from the walls (4, 5, 6) protruding areas are arranged, which are preferably with corresponding counter bearings on the side walls of the chambers (1) are in operative connection or can be brought into operative connection in the course of adjusting the geometry of the walls (4, 5, 6).

38. Wind litter chamber according to one of the preceding claims, characterized in that grooves, blind bores, protrusions, magnets and / or other machine elements are arranged on the inside or in the side walls, which with corresponding counter bearings of the walls (4, 5, 6) a locking or exercise holding function.

39. Wind scattering chamber according to one of the preceding claims, characterized in that the chamber (1) has three areas (I, II, III) with the room heights (2a, 2b, 2c) and particularly preferably four areas (I, II, III , IV) with the room heights (2a, 2b, 2c, 2d) are arranged.

40. A method for scattering and shaping a free-flowing material into a single or multi-layer material fleece on an endlessly revolving molding belt, preferably in the course of the production of material panels in a press, the wind scattering chamber having a chamber with a material supply for introducing material into an air stream, the air flow entering the chamber in a first area via an inlet opening and preferably discharged at the other end of the chamber via an outlet opening, with a different room height being formed in the distance between the ceiling of the chamber and the molding belt, characterized in that in Direction of flow in a second area the room height is steadily reduced by a wall and in a third area the room height is continuously increased by a wall between the ceiling and the molding strip.

41. The method according to claim 20, characterized in that the air flow is guided through a flow obstacle at the transition between the two areas.