EP0975457B1 - Device for fractionating and scattering specially fibrous particles - Google Patents

Description

The present invention relates to a device for the fractionation of especially fibrous particles of different sizes, in particular of lignocellulosic and / or cellulosic fibers, chips or the like Particle, with one containing the unfractionated particle Dosing bunker, essentially one downstream of the dosing bunker flat screening device and a feed unit of the dosing hopper, through which the particles from the dosing hopper onto the surface of the screening device are applicable. Furthermore, the invention is based on a device for sprinkling, especially with binders fibrous particles, in particular wood fibers, wood chips or similar particles, with such a device for fractionation directed.

Devices of this type are from German patent 17 28 502 known. In this document there is a spreading device for production multilayer chip fleece described, in which at the bottom of the unfractionated Particle-containing dosing hopper rake rollers provided are, via which the particles one downstream of the dosing bunker Throwing sight roller are fed. Those hitting the throwing sight roller Particles are fractionated and placed on one below the throwing sight roller arranged vibrating screen thrown. The fractionation takes place on the principle of throwing sighting, so that larger and thus heavier Particles hit an area of the sieve farther from the Throwing sight roller is removed, and smaller particles near the throwing sight roller come to rest on the sieve. By moving the vibrating screen the impacting particles are loosened further, whereupon they through the vibrating screen to produce a fleece on a below of the vibrating screen arranged conveyor belt are poured.

Devices of this type have several disadvantages. For one thing it is inevitable that the screening device used will clog over time, especially since the particles hitting the screening device are usually mixed with binders. A cleaning of the screening device is relatively time-consuming and therefore costly, because during cleaning the operation of the device must be interrupted. On the other hand is both the throughput and the quality of the fractionation Devices of the type mentioned are unsatisfactory.

The object of the invention is a device of the aforementioned Kind in such a way that on the one hand no clogging of the screening device occurs and on the other hand the throughput with simultaneous improvement the quality of sighting can be improved.

Starting from a device of the type mentioned at the beginning, this is Object achieved according to the invention in that in the area of the surface the screening device is a transport device with a plurality of against each other separated, along the surface of the screening device movable portioning sections is provided, within each of which part of that from the feed unit onto the surface of the screening device particles deposited over the surface of the screening device can be transported, in particular moved. The task continues by a device for spreading, in particular with binder staggered, preferably fibrous particles, in particular wood fibers, Wood chips or similar particles, in particular for the production of shaped objects, primarily in the form of plates, with an inventive Fractionation device and one below the screening device arranged conveyor for receiving a the fleece formed particles passing through the screening device.

According to the invention, portioning is thus carried out on the screening device applied particles in mutually independent particle quantities, through the transport device according to the invention the surface of the screening device can be transported away. Through the Movement of the particles along the surface of the screening device will on the one hand prevents the sieve device from sticking and on the other hand generates a force on the particles that is perpendicular to the sieve has pointing component. With this power Particles pushed through the sieve, so that the throughput the device is increased accordingly. By portioning better fractionation of the particles is achieved because within the relatively small amounts of particles, each within a portioning are a more complete mixing of the particles is possible, which prevents small ones from sticking to the top particles in the bulk material have no possibility of past the larger particles below them to the screening device to get.

In the bulk material arranged within the portioning sections creates a rotation or Circulation movement of the particles, which promotes mixing of the particles, which increases the quality of sighting.

According to an advantageous embodiment of the invention comprises at least a portion of the portioning sections each have a grinding element that rests on the surface of the screening device and when moving the portioning sections sanding over the surface of the screening device to be led. By applying a slight pressure to the surface of the screening device abutting grinding element for each or at least one Part of the portioning sections is the cleaning effect that occurs when moving the portioning portions over the surface of the screening device arises, further strengthened. At the same time through the grinding elements that acting on the particles in a direction perpendicular to the screen surface Force component strengthened, so that an increase in throughput is achieved.

The transport device is preferably an in particular endless scraper belt educated. In this way it is a particularly simple and inexpensive Design of the transport device possible. It is Scraper belt advantageously at least over a partial area in one direction perpendicular to the surface of the particle sieve permeable so that the particles from the dosing bunker over its feed unit through the scraper belt onto the screening device can be poured. A complex design of the This eliminates the need for a feed unit.

According to a further advantageous embodiment of the invention the scraper belt in particular plate-shaped carriers, which preferably at regular intervals on an endless chain or ribbon-shaped Carrier element are provided. The carrier element can each be attached to the center of the drivers. However, several, in particular two chain or band-shaped carrier elements are provided be, each in the area of the lateral outer edges of the driver are attached. In this way, the stability of an invention trained scratch tape increased.

The drivers on the carrier element or on the carrier elements are preferred releasably attached and / or airtight. On this ensures that, on the one hand, the carriers used optimally matched to the screening devices used and secondly worn drivers can be exchanged for new ones.

According to a further advantageous embodiment of the invention the grinding elements are each formed by a section of the driver. This is a particularly cost-effective embodiment of the invention Device possible because there are no separate ones for the grinding elements Components are needed. In particular, the drivers are at least flexible in its sections forming the grinding elements, for example made of hard rubber. This is an adjustment of the Abrasive elements on the surface of the screening device possible, so that guaranteed even with a certain irregularity in the screen surface is that the grinding elements over their entire width as well as over their entire range of motion on the surface of the screening device with a certain pressure.

According to a further preferred embodiment of the invention, the Driver at least in their sections forming the grinding elements designed to be abrasion-resistant and in particular have an abrasion-resistant coating, for example a Teflon coating. The grinding elements forming sections of the driver can be both in one piece be formed with the drivers as well as separate components. If the grinding elements are designed as separate components, they are preferred releasably attached to the carriers, so that in the event of a Wear can be exchanged.

According to a further advantageous embodiment of the invention, the Driver at least in their sections forming the grinding elements made of water-repellent, non-stick material. Thereby prevents the particles crosslinked with binder on the carriers stick, which increases the absorption capacity of the portioning could be restricted.

According to a further preferred embodiment of the invention the screening device in particular two screening zones with different Sieve openings. In this way it is achieved that particles are different Size through the sieve zones with sieve openings of different sizes be fractionated. In particular, the screening zones are along the direction of movement of the movable over the surface of the screening device Portioning sections arranged one behind the other, preferably the sieve openings of the portioning sections in the direction of movement lying sieve zone or sieve zones are larger than that Sieve openings of the sieve zone lying against the direction of movement or sieve zones. This ensures that when painting over the screen surface first the small diameter particles through the sieving device step through while finishing it in the next Pass the next larger particles through the sieve zone. Depending on the number of sieve zones and the size of the sieve openings achieved the desired fractionation of the particles. The fractionated Particles can either be different according to the sieve zones Collection devices for the different particle sizes or, for example, to a moving conveyor belt are poured on this way a fleece with particle sizes distributed differently over its thickness can be generated.

According to a further advantageous embodiment of the invention endless scraper belt over two pulleys, so that a lower Band section directly on the surface of the screening device and a upper band section at a certain distance from the surface of the Screening device, in particular in each case essentially parallel to the surface the screening device runs. This way, one is special compact design of a device according to the invention possible. Preferred is at least at one end of the scraper belt, in particular in the area of the deflection rollers, a receiving device for receiving excreted particles provided. With these particles it can foreign bodies present in the bulk material, such as, for example Act screws or nails; however, clumping can also occur or particles that exceed an allowable maximum size, and thus also do not push through the largest sieve openings of the sieve device can be eliminated and removed.

According to a further preferred embodiment of the invention, between the upper and the lower band section at least in some areas an intermediate floor is provided, the drivers with their the the sections forming the grinding elements at opposite ends rest against the intermediate floor so that these ends when moving the portioning be ground over the intermediate floor. With this embodiment can from the dosing hopper over the Feed unit first bulk material applied to the intermediate floor defined spent at a specific position between the pulleys become.

According to a preferred embodiment, the intermediate floor can from one deflection roller in the direction of movement of the upper one Extend the belt section towards the opposite other deflection roller, being between this other pulley and that of this other Deflection roller facing end of the intermediate floor an area is formed in a direction perpendicular to the surface of the screening device is permeable to the particles. Especially if this Area is formed from other screening devices, the relatively large Sieve openings, pre-separation of foreign bodies can occur here or particles with a size larger than the size of these sieve openings lies. Only those that pass through the further screening device Particles fall onto the underlying sieve device, over which they pass be moved away by means of the transport device.

According to a further preferred embodiment of the invention two scraper belts arranged one behind the other in the longitudinal direction, the scraper belts in particular arranged mirror-symmetrically to one another are. The feed unit of the dosing hopper is advantageous a distribution device, in particular in the form of a pendulum distributor downstream with which the feed unit from the dosing bunker removed particles in particular mutually the two scraper belts are feedable. This configuration makes it possible to start out from a dosing bunker particles to two different scraper belts to distribute. Especially when the two scraper belts run in opposite directions are drivable so that the two upper band sections diverge are movable, and between the upper and lower Band section provided an intermediate floor in the manner already described is, can via the distribution device to the respective Intermediate floors applied to particles in opposite Towards the outer ends of the scraper belts there in each case on the screen devices arranged below the scraper belts be applied. With appropriate dimensioning of the Screen openings of these screening devices, especially if the size of the Sieve openings increases in the direction of movement of the lower belt sections, can be arranged on a below the screening devices, moving conveyor belt a symmetrical fleece with a lower one fine top layer and an upper fine top layer between enclose a rough middle class. Instead of one Distribution device can for example also two dosing bunkers be provided through which the two scraper belts are loaded with particles become.

The screening device and / or the additional screening device is preferred in FIG all embodiments as a vibrating screen or as a vibrating shaking screen educated. In this case, that which is placed on the screening device Bulk material is further loosened, making it distant, fine and subsequently medium sized particles faster towards the sieve openings and to get through it.

According to a further preferred embodiment of the invention Vibrating screen can be moved back and forth via a crank mechanism. Here is advantageous the maximum stroke of the vibrating screen between approx. 10 cm and 1 m, preferably between approx. 30 cm and 70 cm, in particular approx. 50 cm.

Through the movement of the vibrating screen, its frequency adjustable the chips lying on the seven are evened out and screened out fractionally according to the sieve openings. The drivers can grind over the surface of the sieves or in one be moved close to it.

The fact that both the driver and the vibrating screen at the same time are in motion and due to the changing direction of movement of the vibrating sieve one rotating and one counter rotating Movement is generated, which are arranged in the portioning sections Particles repeated on the front and back sides of the drivers jammed and turned.

Especially if, according to a preferred embodiment, the maximum Speed of movement of the vibrating screen in the transport direction is greater than the transport speed of the portioning sections, the particles collect at the opposite of the transport direction Sides of the driver when the driver and the vibrating screen in be moved in the same direction. This way the particles pushed and turned against the back of the driver.

The vibrating screen moves against the transport direction of the portioning sections and thus against the direction of movement of the drivers, this is how the particles are circulated on the front sides of the drivers.

This repeated circulation results in an even distribution of the Particles reached within the portioning sections, making it the smaller one Particle allows to move quickly through the total amount inside a portioning arranged particles in the direction of To wander the screen surfaces and to fall through the screen openings.

In addition, due to the simultaneous but different movement speeds and directions of vibrating screen and drivers the self-cleaning effect of the screens increases. Since the bottom edges of the Grind the driver over the surface of the vibrating screen or in one Small distance from this are arranged in the sieve openings stuck particles during the sweep by the driver broken or pushed through the sieve openings. A clogging the sieve is excluded.

According to a further advantageous embodiment of the invention, the Portioning sections laterally closed at least in regions educated. This ensures that particles and Particle dust avoided laterally from the portioning sections is so that the area around the device is kept practically dust-free becomes.

Are advantageous in the lateral areas of the portioning in particular tab-shaped sealing elements are provided, which in particular are attached to the side faces of the drivers. By the tab-shaped sealing element is a simple seal of the Portioning sections possible, with retrofitting of existing ones Devices with the sealing elements allows in a simple manner becomes.

According to a further preferred embodiment, each overlap two sealing elements in succession in the transport direction at least in some areas, which means that each one extends across the entire width of a portioning portion extending seal is generated. This overlapping training takes into account the fact that in the formation of the transport device as an endless scraper belt the drivers when rotating the pulleys on their radial outside edges have a greater distance from each other than between the radially inner edges. Because in this case one tight sealing of the lateral areas of the portioning sections is not possible, the seal can be advantageous by overlapping Sealing elements can be achieved. In principle, it is also possible to form the sealing elements flexibly, for example, wherein the flexibility on the one hand through certain material properties and secondly achieved, for example, by a kind of accordion folding can be.

According to a further preferred embodiment is between the upper and the lower band section laterally outside of the portioning sections a center sealing element, in particular designed as a side wall arranged. Is preferred by the center sealing element essentially the entire area between the upper and lower band section laterally sealed.

The area between the upper one is defined by the central sealing element and the lower band section sealed from the environment, so that the environment is free of dust through the central sealing element is further improved.

Preference is given to the portioning sections on both sides each provided a central sealing element, so that a Prevents dust from escaping into the environment on both sides of the device becomes.

The central sealing element with the portioning sections is preferred sealing sealing elements on the side connected and is particularly in the case of moving sealing elements with these in sealing sliding contact. This way the whole lateral area through an essentially continuous, uniform Sealing unit, consisting of the central sealing elements and the sealing elements that laterally close the portioning sections sealed so that the lateral environment of the invention Device is practically dust-free.

To prevent dust from escaping upwards from the device, is above according to a further advantageous embodiment of the upper band section is designed in particular as a wall section upper sealing element provided.

According to a further advantageous embodiment of the invention a transport device is provided above the portioning sections, with which the particles emerging from the dosing bunker become one predetermined area above the screening device can be transported. In particular, the transport device can be preferably endless Conveyor belt be formed.

The transport device can additionally or instead of the already Intermediate floor described can be provided because the function that from particles emerging from the dosing hopper to a predetermined range to be transported above the screening device, both through the transport device as well as interacting through the mezzanine met with the upper band section moved above the intermediate floor can be. Thus, all of the embodiment with intermediate floor described advantages and combinations of features even with a Device with an in particular designed as an endless conveyor belt Transport device possible and hereby claimed. For example it is possible via the transport device that comes from the dosing bunker in the area of a deflection roller on the transport device given particles towards the opposite other deflection roller and spend there through the scratch tape on the surface to give the screening device.

According to a further advantageous embodiment of the invention an inventive device for scattering particles Fractionator can be moved in the longitudinal direction relative to the conveyor belt educated. As a result, it can be used especially when connecting a cycle press for pressing the fleece, the next fleece by moving the fractionation device in relation to the conveyor belt are scattered so that the next fleece already after pressing is completely scattered and fed directly to the cycle press can.

It is also possible according to the invention that in addition to one or several fractionation devices according to the invention, for scattering one or more top layers are used, middle layer spreading roller heads provided for spreading a middle layer of the fleece are.

Further embodiments of the invention are in the subclaims specified.

Fig. 1

eine schematische Seitenansicht einer erfindungsgemäß ausgebildeten Vorrichtung zur Fraktionierung von faserigen Teilchen, wie beispielsweise mit mindestens einem Bindemittel versetzten Holzfasern, Holzspänen oder dergleichen Teilchen,

Fig. 2

eine Detailansicht zu der in Fig. 1 abgebildeten Vorrichtung,

Fig. 3

eine erfindungsgemäß ausgebildete Vorrichtung zur Bildung eines symmetrischen Vlieses,

Fig. 4

eine weitere Ausführungsform der Erfindung,

Fig. 5

eine teilweise geschnittene perspektivische Darstellung einer weiteren Ausführungsform der Erfindung und

Fig. 6

eine weitere Ausführungsform der Erfindung.

The invention is explained in more detail below using exemplary embodiments with reference to the drawings; in these show:

Fig. 1

2 shows a schematic side view of a device designed according to the invention for fractionating fibrous particles, such as wood fibers, wood chips or similar particles mixed with at least one binder,

Fig. 2

2 shows a detailed view of the device shown in FIG. 1,

Fig. 3

a device designed according to the invention for forming a symmetrical fleece,

Fig. 4

another embodiment of the invention,

Fig. 5

a partially sectioned perspective view of another embodiment of the invention and

Fig. 6

a further embodiment of the invention.

Fig. 1 shows a dosing hopper 1, in which three scraping rakes 2 are arranged are. That from different sized particles 3, for example bulk material consisting of fibrous shavings and binders Dosing hopper 1 fed from above, as indicated by an arrow 4 is.

On the underside of the dosing hopper 1 is a via two deflection rollers 5 running floor conveyor 6 arranged together with a discharge roller 7 forms a feed unit 8.

The particles 3 entered in the dosing hopper 1 fall onto the bottom belt 6 and are indicated there by the back rake 2 in the Equalized arrow directions and along an arrow 9 in the direction of the discharge roller 7 funded.

Below the discharge roller 7 there is a guide that is guided over two deflection rollers 9, 9 ', Endless scraper belt 10 arranged by rotating the pulleys 9, 9 'is movable according to the arrows 11. The scraper belt 11 includes an upper band section 12 and a lower band section 13, the lower band section 13 during a rotation of the deflection rollers 9, 9 'is movable in the direction of an arrow 14.

The scraper belt 10 consists of a band-shaped carrier element 15, on the plate-shaped driver 16 at regular intervals essentially attached perpendicular to the band-shaped carrier element 15 are. Portioning sections are located between the carriers 16 17 formed in a direction perpendicular to the band-shaped Carrier element 15 are permeable.

Below the scraper belt 10 is a vibrating screen 18 Screening device 19 arranged so that the driver 16 of the lower Band section 13 rest with their lower edges on the vibrating screen 18 and when the lower band section 13 moves along the Arrow 14 with a certain pressure across the surface of the Grind vibrating sieve 18. The vibrating screen is about not shown Means according to a double arrow 20 back and forth and includes two sieve zones 21, 22 with different sieve openings 23, 24, wherein the sieve openings 24 formed in the sieve zone 22 are larger than those in FIG the sieve zone 21 are formed sieve openings 23. The screen zones 21, 22 can be used, for example, as mesh, round-hole or elongated sieves or any other known sieve types.

Below the end of the vibrating screen facing the deflection roller 9 ' 18, a receiving device 25 designed as a conveyor belt is arranged, whose direction of transport is perpendicular to the plane of the drawing.

A conveyor belt 26 is provided below the screening device 19 parallel along its conveying direction indicated by an arrow 30 to the direction of movement of the lower one represented by arrow 14 Band section 13 extends.

The particles discharged from the discharge roller 7 from the dosing hopper 1 3 fall through the portioning sections 17 of the upper band section 12 of the scraper belt 10 through it on the surface of the Vibrating sieve 18 land. The movement of the scraper belt 10 a portioning of the continuous particle inflow on the surface of the vibrating screen 18 into individual, within the portioning sections 17 arranged particle portions reached, the individual Portions by the driver 16 over the surface of the vibrating screen 18 can be moved in the direction of arrow 14.

When sweeping over the first sieving zone 21, those particles 3 ′, whose dimensions are smaller than the size of the screen openings 23, by through the screen openings 23 formed in the vibrating screen 18 and fall onto the conveyor belt 26 below. Those particles 3 ", on the other hand, whose dimensions are larger than the size of the screen openings 23, are by the driver 16 over the surface of the vibrating screen 18th moved until they reach the second screening zone 22. When painting over The sieve zone 22 enters those particles 3 ″ whose dimensions are smaller than the size of the screen openings 24, through the vibrating screen 18 and fall onto the conveyor belt 26 below. Particles 3 "', which are larger than the screen openings 24, such as excessive Large fiber particles, clumps or foreign bodies fall after leaving the sieve zone 22 on the receiving device 25 and of this transported away.

Form the particles 3 ', 3 "passing through the vibrating screen 18 on the conveyor belt 26 a fleece 27, the vibrating screen 18 in the area the small particles 3 'passing through the first sieving zone 21 first impinge on the conveyor belt 26 and thus a lower layer 28 of the Form fleece 27. The in the area of the second sieve zone 22 by the Large particles 3 "passing through the vibrating sieve fall through on the the small particles 3 'form lower layer 28 and form an upper one Layer 29.

The fleece 27 formed in this way can on the conveyor belt 26 in Direction of arrow 30 transported to a press device, not shown and in this device in a manner known per se Plate to be pressed. It is also possible and within the scope of the invention advantageous, the device of Figure 1, another device of this Sort in such a mirror-image order that additional large fleece 27 Particles 3 "and then small particles 3 'arrive, making one symmetrical constructed and compressible into a shaped object Fleece receives. Such a device is described with reference to the figure 3 described in more detail below.

According to the detailed view shown in Fig. 2 are on the drivers 16 approaches 31 are formed, via which the driver 16 releasably on the band-shaped carrier element 15 are attached.

The drivers 16 are flexible, so that the lower sections 32 of the driver 16, when the lower band section moves 13 drag along the arrow 14 over the surface of the vibrating screen 18, assume the curved shape shown in Fig. 2. Due to the curved shape of the lower portions 32 of the driver 16 acts on those within the portioning sections formed between the carriers 16 17 arranged particles 3 one in the direction of an arrow 33 directed force that a component perpendicular to the surface of the Vibrating sieve 18 has. Because of this power, those within the Portioning sections 17 arranged particles 3 in the direction of Vibrating sieve 18 pressed, whereby the throughput through the vibrating sieve 18 is increased. Furthermore, the pushing movement creates the driver 16 arranged in the portioning portions 17 Portions of the particles 3 a circulating movement indicated by arrows 34, so that distant small particles 3 due to this Circulating movement is conveyed towards the surface of the vibrating screen 18 are and penetrate the vibrating screen 18 through the screen openings 23 can.

Furthermore, it is apparent from Fig. 2 that by the surface of the Vibrating screen 18 traversing sweeping driver 16 a setting the vibrating screen 18 is prevented, so that expensive cleaning the vibrating screen 18 is not required.

In the embodiment shown in Fig. 3, in the case of the device 1 identical element with the reference numerals used in Fig. 1 are provided instead of a scraper belt with a downstream Screening device two lying one behind the other in the longitudinal direction arranged scraper belts 35, 36 are provided, each one as Vibrating sieve 37, 38 formed sieving device 39, 40 connected downstream is.

The scraper belts 35, 36 are essentially identical to that of FIG. 1 described scraper belt 10 and are formed over the deflection rollers 9, 9 'driven in opposite directions, as indicated by arrows 41 to 44 is.

The scraper belt 35 includes an upper belt section 45 and one lower band section 46, being on the underside of the upper band section 45 an extending over the entire width of the scraper belt 35 Intermediate floor 47 is arranged. The intermediate floor 47 is positioned so that the inner edges of the driver 16 on abut the top of the intermediate floor 47 and with a rotation of the Scraper belt 35 are guided over the intermediate floor 47.

The intermediate floor 47 extends from the inside deflection roller 9 to just before the outer pulley 9 ', between the end 48 of the intermediate floor 47 and the outer deflection roller 9 ', an area 49 is formed which is perpendicular in one direction is designed to be permeable to the vibrating sieve 37 for the particles 3.

Similarly, the scraper belt 36 includes upper and lower belt sections 50, 51, on the underside of the upper band section 50 an intermediate floor 52 is provided on which the inner edges the driver 16 abut and over these edges during a rotation the scraper belt 36 are guided grinding.

In the area between the discharge roller 7 and the scraper belts 35, 36 a pendulum distributor 53 is arranged, the two along an arrow 54 around Axes 55 hinged pendulum flaps 56 and a wedge-shaped separating element 57 with two inclined surfaces 59, 60, the tip 58 in the center is directed between the axes 55.

Out of the dosing bunker 1 through the discharge roller 7 Scattered material is obtained by pivoting the pendulum flaps 56 in the same direction alternately on the inclined surfaces 59 and 60 of the wedge-shaped fuel assembly 57 passed, of which the particles 3 of the grit each the scraper belt 35 and 36 are guided.

The particles 3 fall on the intermediate floors 47 and 52, being inside the one formed between two adjacent drivers 16 Portioning sections 17 containing a certain amount of particles 3 Portions of the grit are formed. These servings are driven by the moving over the intermediate floors 47, 52 16 promoted in the direction of the outer deflection rollers 9 ', where after exceeding the ends 48, 61 of the intermediate floors 47, 52 through the open areas 49, 62 downward in the direction of the vibrating screens 37, 38 fall.

The particles 3 falling on the surface of the vibrating screens 37, 38 become as already described for Fig. 1, according to their size fractionated, in the embodiment of FIG. 3 due to symmetrical design with two mirrored scraper belts 35, 36 on the conveyor belt 26 a symmetrical fleece 27 with two small ones Outer layers 63, 64 containing particles 3 'and a large particle 3 "containing inner layer 65 is formed.

Too large particles 3 "'are each on the inner pulleys 9 deposited on a receiving device 25 and transported away from it.

In the embodiment shown in Fig. 4, in the Figs. 1 and 3 identically designed elements again with the same reference numerals as indicated in Figures 1 and 3 is below the upper band section 50 an intermediate floor 66 is arranged, at the end 67 of which another sieving device 68 connects, the ones located inside Edges of the drivers 16 upon rotation of the scraper belt 36 both over the surface of the intermediate floor 66 as well as over the surface the further sieving device 68 are guided grinding.

A sieve device 69 is arranged below the lower belt section 51, over the surface of the outside edges of the driver 16 are guided by grinding when the scraper belt 36 rotates.

The further screening device 68 has screening openings 70 and the screening device 69 has sieve openings 71, the sieve openings 70 being larger than the sieve openings 71 are formed.

Below the scraper belt 36 are three collecting devices 72, 73, 74 provided, the collecting device 72 over the length and Width of the screening device 69, the collecting device 73 in the area below the deflection roller 9 'and the collecting device 74 in the area below the pulley 9 are.

Become particles 3 according to arrow 4 on the surface of the intermediate floor 66 given, the particles 3 in portions by the driver 16 of the scraper belt 36 over the surface of the intermediate floor 66 to the end 67 and then over the surface of the screening device 68 led. Since the sieve openings 70 of the sieve device 68 are relatively large, essentially all particles 3 fall through the sieve openings 70 through to the surface of the screening device 69. Only Particles 3 '", which defined an allowable, by the size of the sieve openings 70 Exceed maximum size, are up to the guide roller 9 ' guided the surface of the screening device 68, where it then into the Recording device 73 fall and further processed or discarded become.

The particles 3 hitting the surface of the screening device 69 become by the driver 16 in individual portions over the surface the sieve device 69, wherein particles 3 ', their dimensions are smaller than the size of the screen openings 71 pass through them and can be caught by the receiving device 72.

Particles 3 "whose dimensions are below the size of the sieve openings 70, but above the size of the sieve openings 71, are about the end of the screening device 69 is conveyed out and falls into the receiving device 74.

The device described thus separates particles different sizes possible. Instead of a sieve device 69 also two or more screening devices connected in series be provided with sieve openings of different sizes, in which case a separate one under each of these screening devices Collecting device for collecting the one corresponding to the respective sieve opening Particle is present.

In the embodiment shown in Fig. 5 are again already elements described for Figures 1 to 4 with the same reference numerals Mistake.

As can be seen in FIG. 5, the drivers are on the end faces 16 plate-shaped elements 80 are provided, which over the approaches 31st with the band-shaped carrier element 15 designed as a link chain are connected. The sealing elements essentially have one rectangular shape and such a size that the ends of two adjacent sealing elements 80 overlap when the associated drivers 16 are guided over the screening device 19.

In the area of the deflection rollers 9, 9 ', the radially outer ones are removed Edges of two adjacent sealing elements 80 from each other, see above that a V-shaped gap 81 between two adjacent sealing elements arises.

In order to allow a problem-free overlap of the sealing elements 80, are the mutually opposite overlap areas 82, 83 of a sealing element 80 arranged laterally offset from one another, so that the overlap area 82 faces outward and the overlap area 83 is offset inwards, which makes it as smooth as possible These end regions 82, 83 overlap with the corresponding ones End regions 82, 83 of the adjacent sealing elements 80 enables becomes.

Both in the upper and in the lower band section 12, 13 are the Portioning sections 17 through the sealing elements 80 laterally essentially completely sealed so that leakage from into the Portioning sections 17 arranged particles or dust reliably is prevented.

In the area between the upper and lower band sections 12, 13 a center sealing element 84 designed as a side wall is provided, of the only in Fig. 5 due to the partial section shown respective end regions 84 'and 84 "are shown. The center sealing element 84 is abrasive at its upper and lower edges 85, 86 Contact with the radially inner edges of the sealing elements 80, so that over the entire side surface of the scraper belt 10th sealing against leaking particles or dust.

This ensures that, for example, the link chain band-shaped carrier element 15 and those provided with teeth Deflection rollers 9, 9 'and the other external elements of the Device remain essentially dust-free.

Above the upper band section 12 there is only one in FIG. 5 Upper sealing plate 87 shown arranged, which is also a leak prevented from dust upwards.

The screening device 19 is in the embodiment shown in FIG. 5 from five sieve zones 75 to 79, each different large sieve openings, the size of the sieve openings from the sieve zone 75 increases to the sieving zone 79. Depending on the application, a different one Number of different screening zones can be provided, so that the structure and quality of what is produced with the device Control fleece.

The movement of the screening device 19 designed as a vibrating screen 18 according to the double arrow 20 in the illustrated embodiment generated by a crank mechanism 88, the rotational speed of which is preferred is adjustable. The crank mechanism 88 comprises a crank rod 89, the End 90 connected to a roller guide 92 via a joint 91 is.

The roller guide 92 comprises a stationary, with rollers provided rail 93 on which a roller block 94 is slidably mounted is. The roller block 94 is connected to the screening device 19, so that when the roller block 94 is moved along the rail 93, the vibrating screen 19 is also displaced via the crank mechanism 88 becomes.

By means of the crank drive 88 a very smooth and controlled Back and forth movement of the screening device generated.

The link chain 15 can, for example, also be a roller chain or other suitable band-shaped carrier element may be formed. As well the sealing elements 80 can have a different shape as long as it is ensured that, in particular when painting over the screening device 19 through the portion 16 through the portioning the sealing elements 88 are essentially laterally sealed.

6 shows a device designed according to the invention, which essentially corresponds to the device shown in FIG. 3. Instead of Intermediate floors 47, 52 shown in FIG. 3 are two endless conveyor belts 95, 96 are provided, on which out of the dosing bunker 1 conveyed particles 3 are spent on the pendulum distributor 53. The Conveyor belts 95, 96 are driven in the direction of arrows 97, 98, so that the particles lying on the conveyor belts 95, 96 3 in Direction of the open areas 49, 62 are transported and through this fall through in the direction of the vibrating screen 37, 38.

The same functionality can thus be achieved by the conveyor belts 95, 96 are as by the intermediate floors 47, 52 shown in Fig. 3. It is advantageous that the use of the intermediate floors 47, 52 existing friction between the lower edges of the driver 16 and the intermediate floors 47, 52 and the associated wear avoided becomes. The conveyor belts 95, 96 can in all embodiments can be used instead of the intermediate floors, so that for example a device according to FIG. 4 in a corresponding manner Conveyor belts can be built.

Basically, in addition to all described devices the screening described a sighting of a known type, such as a wind sighting can be made to improve the sighting quality further increase. This can be achieved in that between the described screening devices and the one below Conveyor belt a device for wind sifting is arranged.

Claims (18)

1. Apparatus for the fractionation of particles, especially fibrous particles (3), of different sizes, in particular of fibres chips or the like containing lignocellulose and/or cellulose, comprising a metering hopper (1) containing the non-fractionated particles (3), a substantially areal screening apparatus (19, 39, 40, 68, 69) inserted after the metering hopper (1) and a supply unit (8) of the metering hopper (1) by which the particles (3) from the metering hopper (1) can be brought onto the surface of the screening apparatus (19, 39, 40, 68, 69),
   characterized in that
   a transport device (10, 35, 36) is provided in the region of the surface of the screening apparatus (19, 39, 40, 68, 69) having a plurality of portioning segments (17) separated from one another and movable along the surface of the screening apparatus (19, 39, 40, 68, 69) within each of which a respective portion of the particles (3) brought by the supply unit (8) onto the surface of the screening apparatus (19, 39, 40, 68, 69) is transportable and in particular movable over the surface of the screening apparatus (19, 39, 40, 68, 69).
2. Apparatus in accordance with claim 1,
   characterized in that
   at least some of the portioning segments (17) each include a scraping element (16, 32) which contacts the surface of the screening apparatus (19, 39, 40, 68, 69) and is scrapingly guided over the surface of the screening apparatus (19, 39, 40, 68, 69) during the movement of the portioning segments (17).
3. Apparatus in accordance with claim 1 or claim 2,
   characterized in that
   the transport device (10, 35, 36) is formed as an in particular endless scraper belt, with in particular the scraper belt (10, 35, 36) being made permeable to the particles (3) at least over a partial region in a direction perpendicular to the surface of the screening apparatus (19, 39, 40, 68, 69).
4. Apparatus in accordance with claim 3,
   characterized in that
   the scraper belt (10, 35, 36) includes in particular plate-like drivers (16) which are preferably provided at regular intervals on one or more endless chain- or belt-like carrier elements (15).
5. Apparatus in accordance with claim 4,
   characterized in that
   the drivers (16) are releasably secured to the carrier element (15) or to the carrier elements (15) and/or are made impermeable to air; and/or in that the drivers (16) are arranged substantially perpendicular to the surface of the screening apparatus (19, 39, 40, 68, 69); and/or in that the scraper elements are each formed by a section (32) of the drivers (16); and/ or in that the drivers (16) are made flexible for example of hard rubber, in particular in their sections (32) forming the scraper elements; and/or in that the drivers (16) are made abrasion-resistant, in particular in their sections (32) forming the scraper elements and in particular have an abrasion-resistant coating, for example a Teflon coating; and/or in that the drivers (16) are made of a water repellent non-adherent material, in particular in their sections (32) forming the scraper elements.
6. Apparatus in accordance with any of the preceding claims,
   characterized in that
   the screening apparatus (19, 39, 40, 68, 69) includes in particular two screening zones (21, 22) with different screen openings (23, 24, 70, 71); in particular in that the screen zones (21, 22) are arranged behind one another along the direction of movement of the portioning segments (17) movable over the surface of the screening apparatus (19, 39, 40, 68, 69), with preferably the screen openings (24) of the screen zone (22) or screen zones lying in the direction of movement of the portioning segments (17) being larger than the screen openings (23) of the screen zone (21) or screen zones lying opposite to the direction of movement.
7. Apparatus in accordance with any of claims 3 to 6,
   characterized in that
   the endless scraper belt (10, 35, 36) is guided over two deflection rollers (9, 9') so that a lower belt section (13, 46, 51) extends directly on the surface of the screening apparatus (19, 39, 40, 68, 69) and an upper belt section (12, 45, 50) extends at a specific spacing from the surface of the screening apparatus (19, 39, 40, 68, 69), in particular in each case substantially parallel to the surface of the screening apparatus (19, 39, 40, 68, 69); in particular in that a receiving apparatus (26, 73, 74) for the reception of separated out particles is provided at least at one end of the scraper belt (10, 35, 36), in particular in the region of the deflection rollers (9, 9').
8. Apparatus in accordance with one of the preceding claims,
   characterized in that
   at least one catcher device for the particles (3') sifted through the screening apparatus (69) is provided beneath the screening apparatus (69).
9. Apparatus in accordance with claim 7 or claim 8,
   characterized in that
   an intermediate floor (47, 52, 66) is provided at least regionally between the upper and the lower belt sections (45, 50, 46, 51) and in that the ends of the drivers (16) opposite to the sections (32) forming the scraper elements contact the intermediate floor (47, 52, 66) such that they are guided on movement of the portioning segments (17) scrapingly over the intermediate floor (47, 52, 66), with in particular the intermediate floor (47, 52, 66) extending from the one deflection roller (9) in the direction of movement of the upper belt section (45, 50) to the other, oppositely disposed deflection roller (9') and with a region (49, 62, 68) being formed between this other deflection roller (9') and the end (48, 61, 67) of the intermediate floor (47, 52, 66) facing this other deflection roller (9') and being permeable for the particles (3) in a direction perpendicular to the surface of the screening apparatus (39, 40, 69), with preferably the region being formed as a further screening apparatus (68).
10. Apparatus in accordance with any of claims 3 to 9,
    characterized in that
    two scraper belts (35, 36) in particular scraper belts formed with mirror image symmetry are provided lying behind one another in the longitudinal direction; and in particular in that a distribution apparatus, in particular in the form of a pendulum distributor (53), is connected after the supply unit (8) with which the particles led out from the metering hopper (1) by the supply unit (8) can in particular be alternately supplied to the two scraper belts (35, 36).
11. Apparatus in accordance with any of the preceding claims,
    characterized in that
    the screening apparatus (19, 39, 40, 69) and/or the further screening apparatus (68) is formed as an oscillating screen (18, 37, 38) or as a vibrating shaking screen, with in particular the oscillating screen (18) being movable to and fro via a crank drive (88), and/or the maximum stroke of the oscillating screen (18) amounting to between approx. 10 cm and 1 m, preferably to between approx. 30 cm and 70 cm, in particular to approx. 50 cm, and/or the oscillating screen (18) being displaceable along a roller guide (92), and/or the maximum speed of movement of the oscillating screen (18) in the transport direction being greater than the speed of transport of the portioning segments (17).
12. Apparatus in accordance with claim 10 or claim 11,
    characterized in that
    the two scraper belts (35, 36) can be driven in opposite directions, in particular with the two upper belt sections (45, 50) being movable away from one another.
13. Apparatus in accordance with any of the preceding claims,
    characterized in that
    the portioning segments (17) are made at least regionally closed at the side; and/or in that sealing elements (80), in particular lobe-like sealing elements, are provided in the side regions of the portioning segments (17), with in particular the sealing elements (80) being secured to the lateral end faces of the drivers (16), and with preferably in each case two sealing elements (80) which follow one another in the transport direction overlapping at least regionally, whereby in each case a seal is produced which extends over the full width of a portioning segment.
14. Apparatus in accordance with any of claims 7 to 13,
    characterized in that
    a middle sealing element (84), in particular formed as a side wall, is arranged between the upper and the lower belt sections (12, 13) laterally outside of the portioning segments (17); in particular in that substantially the entire region between the upper and the lower belt sections (12, 13) is laterally sealed by the middle sealing element (84); and/or in that a respective middle sealing element (84) is provided at each side outside of the portioning segments (17); and/or in that the middle sealing element (84) is sealingly connected to the sealing elements (80) which laterally close off the portioning segments (17) and in particular stands in sealing and scraping contact with moved sealing elements (80).
15. Apparatus in accordance with any of claims 7 to 14,
    characterized in that
    an upper sealing element (87), in particular an upper sealing element formed as a wall section, is provided above the upper belt section (12).
16. Apparatus in accordance with any of the preceding claims,
    characterized in that
    a transport device (95, 96) is provided above the portioning segments with which the particles which emerge from the metering hopper are transportable to a predetermined region above the screening apparatus, with preferably the transport apparatus being formed as a transport belt (95, 96), in particular as an endless transport belt.
17. Apparatus for the scattering of preferably fibrous particles (3), in particular particles mixed with a binder, such as for example fibres, chips or the like particles containing lignocellulose and/or cellulose, in particular for the manufacture of shaped articles, principally in the form of boards, comprising an apparatus for the fractionation in accordance with one of the preceding claims and a conveyor belt (26) arranged beneath the screening apparatus (19, 39, 40) for the reception of a mat (28, 63) formed of particles (3, 3") which pass through the screening apparatus (19, 39, 40).
18. Apparatus in accordance with claim 17,
    characterized in that
    the fractionating apparatus is made movable in the longitudinal direction relative to the conveyor belt; and/or in that middle layer roller scattering heads are provided for the scattering of a middle layer of the mat in addition to one or more fractionating apparatuses in accordance with one of claims 1 to 16 for the scattering of one or more cover layers.

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