EP2739398B1 - Method and device for producing organic fibrous materials or granulates - Google Patents

Description

The present invention relates to a method and a device for producing organic fibrous materials and / or granules, in which a batch is comminuted in an interior of a device for comminuting materials by an impact load.

The DE 199 15 154 A1 shows a process for the production of porous composite materials from renewable raw materials by combination and thermomechanical preparation and hydro-thermal treatment. In this process, wooden parts are shredded using a shredder and then fiberized in a twin-screw extruder system with the addition of a magnesium / calcium mixture and biogenic silica, whereby cell structures and lignin bonds in the wood are broken up using pressure, temperature and mechanical processing.

From the DE 102 42 770 A1 a process for the production of wood fiber insulation boards is also known in which wood chips are ground in a refiner using the dry process.

Furthermore, from the WO 97/18071 A1 a method and an apparatus for processing components made of mixed plastics and other construction materials mixed with them, such as metal parts, glass, rubber, wood, fiber materials and the like Known, the components are crushed in an agglomerator by an impact and the plastic, metal, glass, rubber and wood parts and fibers are separated from each other or the plastics are processed into granules or as a mass in the plastic state.

Furthermore, from the US patent application US 3,268,179 A. a pulverizer especially for soy or corn known according to the preamble of the device claim 11, in which organic substances are also crushed by impact.

It is the object of the present invention to provide a method and a device for producing organic fibrous materials or granules, which are inexpensive and save resources.

This object is achieved by the method with the features of claim 1 and by the device with the features of claim 11. Preferred embodiments are the subject of the dependent claims.

According to the present invention, a method for producing organic fibrous materials or granules is proposed, in which a batch comprising at least one fiber-containing organic material is introduced into an interior of a device for comminuting materials by an impact stress and comminuted in this interior by impact impact, whereby a organic fiber or an organic granulate is removed from the interior. The removal takes place by means of a suction pipe protruding into the interior, the suction pipe being pivotable perpendicular to a longitudinal axis of the interior and / or is displaceable and wherein the suction tube has at least one double-walled section with injection nozzles.

Granules in the sense of the present invention are understood to mean a fraction with granular constituents with a size from the macroscopic to the nm range.

In particular, an organic fibrous material and an organic granulate can also be produced in parallel by means of the method according to the invention.

Furthermore, according to the present invention, a device for producing organic fibrous materials or granules with an interior space for receiving a batch comprising at least one fiber-containing organic material is provided, the device being set up for crushing the batch received in the interior space by an impact load, and wherein the device furthermore has at least one removal device for removing the fibrous material or granulate from the interior. The removal device has at least one suction tube projecting into the interior, the suction tube being pivotable and / or displaceable perpendicularly to a longitudinal axis of the interior, and wherein the suction tube has at least one double-walled section with injection nozzles.

In contrast to known energy-intensive processes for fiber production in the insulation and paper industry, which use wet processes and dry processes with defibrillation in refiners called refiners, and in which fiberboard are pressed and dried, the present invention makes cold mechanical processing more organic Fibers and granules made possible by means of a device called crushing reactor for crushing materials by an impact load in a non-cutting or non-cutting process. There is no need for an energy-intensive thermal preheating process, such as the pre-cooking of wood chips, nor the use of large electric drives or complex drying processes. As a result, there is little need for water, thermal and electrical energy, and there is hardly any waste water. In addition, inexpensive raw and residual materials can be used. Overall, the method according to the invention and the device according to the invention are thus inexpensive and resource-saving. In addition, the mechanical tool wear in the device according to the invention is considerably less than, for example, in the case of a refiner.

The invention is used, inter alia, in the wood-based materials industry, in the insulation material industry, in the building materials industry and in particular in the production of vapor diffusion-open and windproof DWD boards, that is to say statically stable or flexible insulation boards, in the production of thermoplastically processable composite materials, in the fiber processing industry, the wood dust processing industry, the food and feed industry as well as the specific raw material logistics. Process parameters and possible installations in the device or in its interior can be adapted or set accordingly to desired processes or to intermediate or end products.

In the device, which can be designed in particular as an impact reactor, one or more removal devices, such as sieves, can be provided at different positions or flaps. Separation systems such as screening plants or centrifugal separators such as cyclone separators or cyclones and wet separators can be arranged downstream of the extraction devices. In principle, any combinations of such elements are possible, and separators can be provided both in parallel and sequentially in any order.

The batch may comprise only one type of fibrous organic material, but may also contain several types of such materials. For example, the batch can consist of a mixture of different fiber-containing organic materials.

An automatic control for the method or the device can be provided. One or more parameters such as the power consumption of the device, the geometry of the device, the dwell time of the batch in the device or the degree of filling of the interior of the device can be used for this purpose.

In order to avoid premature drying of (wood) fibers, which become brittle and can break, within the device, heating of the batch introduced into the device is advantageously avoided. The operating temperature of the device is therefore preferably less than approximately 50 ° C. For example, granular dry ice can be provided for cooling, as is also used as a sand substitute for sandblasting processes. Dry ice is advantageous because, on the one hand, it increases the degree of filling of the device and, on the other hand, it further supports the comminution process, but does not further moisten the reaction material. The installation of cooling fins in the outer walls of the reaction chamber or the intake of cooling air can serve to regulate the temperature of the reaction space.

With the present invention, in particular residual wood batches can be used that could not previously be used for fiber production, which again results in considerable savings in production costs. The fibrous organic material is therefore preferably wood and / or a wood-like material and / or a first shredder, for example of shredding places and / or a residue from paper production and / or waste paper and / or straw and / or about grain husks and / or crop residues from agriculture. For example, the material can be raw wood such as wood chips, chopped wood, residual wood from the paper industry, woody parts from hedges and shrub clippings, wood from short rotation plantations (SRC) or other wood-like and fiber-containing biomass. In particular, processing bark, in particular softwood bark, is also conceivable as a waste product from sawmills. An admixture of hardwood to softwood with a proportion of approximately 10% to 15% has proven to be particularly advantageous, since this improves the quality of the fibers produced in such a way that longer fibers with a length of more than 2.5 mm can be obtained. In this way, fibers can be obtained for the production of compressed insulation boards made of wood materials, blow-in insulation materials made of wood and cellulose fibers. Fibers or granules can also be obtained for sprayable and extrudable biopolymers as well as so-called wood-plastic composites or WPC.

For the production of fibrous materials, it is advantageous if the starting material contains a certain proportion of water, preferably between about 35-55% by weight. With a lower moisture content, primarily granules are produced.

The ratio between the volume of the batch and the volume of the interior before the onset of impact is particularly preferably below 6% or 5% or between 3% and 6% or between 3% and 5%. This ratio or the degree of filling of the device can be measured, for example, by the load on a motor driving the device. If the degree of filling is above 6%, the speed of particles of the batch moving in the interior decreases, or the batch no longer frayed and is merely stirred and heated. If the motor is a two-pole motor, a speed of 2800 rpm or a speed of between 1800 rpm and 3000 rpm is preferably set for this. The decisive factor is the achievement of a certain peripheral speed of the rotor.

In a preferred embodiment, the fibrous material or the granulate is at least partially removed by suction from the interior of the device and / or the fibrous material and / or the granulate is at least partially removed from the interior of the device during operation. For extraction, the removal device has at least one suction tube protruding into the interior. The suction tube can be pushed into the interior with a variable depth of penetration and / or can be pivoted and / or displaced perpendicularly to a longitudinal axis of the interior and / or can be pivoted and / or displaced parallel to a longitudinal axis of the interior to move the fiber material or granules out at various points in the interior to be able to suck it off. The suction can depend on the type of turbulence generated and desired Fiber quality additionally or alternatively also take place above the actual impact space; if two or more suction devices are used, their suction ratio to one another can be designed to be adjustable. In addition to the suction, the removal of a sieve fraction can also be provided, which contains both considerable proportions of fiber material and coarse material. Such coarse materials can then be screened out using a sieve cascade.

One or more steering or wing elements can be provided in the interior of the device according to the invention in order to direct air or material flows in the interior. If the extraction device has a suction pipe, this is preferably arranged on the lee side of the steering or wing element in order to prevent undesired penetration of material into the suction pipe and thereby to achieve the best possible suction results.

In order to be able to ensure a suction cross-section that is as constant as possible and thus material flow during operation, the suction pipe has at least one double-walled section with injection nozzles. According to an example which does not form part of the invention, the suction pipe can be equipped with a cleaning device, in particular a preferably displaceable screw.

The fibrous material and / or the granulate can be removed from the interior either continuously and / or discontinuously. For example, the fibrous material can be continuously sucked out of the interior while the device is in operation, while coarse parts are removed from the interior through a flap or a sieve after certain time intervals.

Part of the organic material can advantageously be removed from the interior and then reintroduced into it. For example, coarse parts, which have not yet been shredded to a predetermined size, can be inadvertently returned to the device in order to be further shredded there.

A gas with an oxygen content of less than 13% or cold flue gas, in particular dedusted by means of a fine dust filter, can advantageously be introduced into the interior as the conveying or intake air. This is particularly advantageous if the fibrous materials or granules are dry and dust-forming and therefore explosive, since the addition of such a gas reduces the risk of explosion. Preference is given to integration on the smoke and heat side in a biomass power plant, in which it is particularly preferred to burn off from the organic solids and granules to be comminuted before the comminution as parts which are unusable in terms of material.

The batch can be introduced into the interior using a mechanical or pneumatic dosing device. It can be conveyed over belts, conveyor rollers, spiked rollers, cups or screws and can be introduced in different denominations, material mixtures and degrees of moisture.

A suitable choice of the dosing devices can be used, for example, to pre-shred or pre-condition the material.

The fact that the fibrous material and / or the granulate is measured with regard to the particle size by means of an ultrasound or optical method at discrete points in time or continuously means that continuous process monitoring can be achieved with the aim of optimum quality of the product obtained. For example, measuring points such as optical measuring devices can be provided at the end of a suction pipe of the removal device or in the interior of the device according to the invention, in order to measure the humidity and the temperature there. Using a high-speed camera in conjunction with an image evaluation or a particle measuring device, the fiber quality can be determined in situ while the method according to the invention is being carried out and, if necessary, used as an input variable for adjusting the intake pipe.

Fig. 1

eine vereinfachte schematische Darstellung einer beispielhaften Vorrichtung, die kein Teil der Erfindung bildet, in räumlicher Ansicht und in der Draufsicht;

Fig. 2

eine Anlage mit einer erfindungsgemäßen Vorrichtung;

Fig. 3

ein verstellbares Absaugrohr einer erfindungsgemäßen Vorrichtung.

The invention is explained in more detail below on the basis of exemplary embodiments with the aid of figures. Show it:

Fig. 1

a simplified schematic representation of an exemplary device that does not form part of the invention, in a spatial view and in plan view;

Fig. 2

a system with a device according to the invention;

Fig. 3

an adjustable suction pipe of a device according to the invention.

A highly simplified and schematic illustration of an exemplary device 1 is shown in FIG Figure 1 shown. A cylindrical interior 2 can be seen Impact reactor device 1, into which a suction pipe 3 of a removal device, not shown, protrudes. Furthermore, in the vicinity of the bottom of the interior 2 is arranged in the rotor 4 in the interior 2, which can be rotated by a drive motor 5 positioned outside the interior 2.

In order to crush a batch of a fiber-containing organic material, the batch is filled into the interior 2 of the impact reactor 1 by means of a metering device, not shown in the figure. The filling process is supported by the negative pressure which arises during the operation of the impact reactor 1. Gravity also has a supporting effect when filling from above. It can also be filled in parallel by means of, for example, a feed screw from the side or tangentially into the interior. The rotor 4 is set in rotation by means of the drive motor 5. The one in the Figure 1 clockwise rotating rotor 4 generates, at a corresponding speed of rotation in the interior 2, an air vortex rotating in the same direction as the rotor 4, which entrains and swirls the fibrous organic material filled into the interior 2. This results in multiple impacts of the material against the wall of the interior 2 and / or against impact elements (not shown in the figure) and the rotor 4, but also of parts of the material with one another. As a result of these sometimes very violent impacts, the material is crushed or shredded. The strong, spontaneous mechanical force input heats the moist woody parts to the point of evaporation and thus helps to shred them without destroying the individual fibers. Depending on the speed of rotation, the time and the type and moisture content of the Material can be separated down into individual fibers.

By adding finely structured, wood-like material such as green waste or SRM material, a damping effect can be achieved, which leads to an improvement in fiber quality. Additions of approx. 10-20% by weight green waste to softwood chips are particularly advantageous here.

Since, due to the centrifugal forces and the inertia, heavier particles move on a trajectory with a larger radius than lighter particles, the size of the shredded material in the vortex decreases towards the center of the interior 2 or towards its longitudinal axis 6. By means of the suction tube 3, which as in the double arrows in the Figure 1 indicated, can be pushed as far as possible into the interior 2 and can be pivoted or displaced perpendicularly and parallel to the longitudinal axis 6 of the interior 2, by placing an opening of the suction tube 3 in the interior 2 appropriately during the operation of the impact reactor 1, fibers or fibers resulting from the crushed organic material Granules of different sizes can be sucked out of the interior 2. The opening of the suction pipe 3 can be positioned on a side facing away from the air vortex prevailing in the interior 2. In other words, the opening is placed on the lee side with respect to the air vortex.

The suction pipe 3 is equipped with the optionally reversible cleaning unit 31, which is designed as a screw in the present example and is not claimed, through which clogging of the suction tube by the extracted material can be avoided. According to the invention, in order to prevent the sticking of moist fiber material in the interior of the suction tube 3, a double-walled suction tube with injection nozzles is provided instead of the cleaning unit 31 designed as a screw. In other aspects, the device according to the invention is similar to the device according to Fig. 1 , The above-mentioned double-walled suction pipe with injection nozzles can be used to clean the inside of the pipe by cyclically building up an overpressure in the double wall. Alternatively or additionally, a kind of air cushion can be generated in the area of the inner wall of the suction pipe 3 by a constant overpressure in the double wall, whereby moist fiber material is kept away from the wall and the same can be prevented from becoming stuck.

In the Figure 2 the impact reactor 1 is shown as part of a larger plant 7 for producing fiber material from raw wood (A) obtained in different fractions. In the following, individual components of system 7 and their functions in the overall operation of system 7 are described.

The raw wood (A) mentioned is, for example, wood chips, first shredded material or wood-like residues of approximately 250 mm to 300 mm in length and an approximate diameter of up to approximately 100 mm, with around 10% to 15% of the raw wood (A ) consist of hardwood, which are cleaned, classified and homogenized in a separator 8 of the plant 7, such as a gravity classifier, a star or drum sieve or an impact reactor similar to the impact reactor 1. If an impact reactor is used as the separator 8, this can be equipped with sieves or flaps for material removal; otherwise it can be constructed essentially identically to the impact reactor 1. It is also conceivable to use only one impact reactor in total, which can be used sequentially as a classifier or pre-shredder (see BZ 8) and as a shredder (see BZ 1). The classification of the raw wood (A) in an impact reactor is preferred, since in addition to the first comminution of the raw wood (A), extensive homogenization, demineralization and debarking can also be carried out in a single pass. Grain fractions 9, which are unusable for further material use, since they contain, for example, a high mineral fraction or a high proportion of contaminants or bark fractions, are discharged and can, for example, be used for thermal purposes. For example, it is possible to provide a biomass power plant in the plant 7 in order to generate heat from the grain fractions 9 by combustion and to use this heat elsewhere in the plant 7, for example as drying heat.

Good grain A1 obtained as oversize or undersize is first conveyed into a metering container 10 and from there via a metering device 11 into the impact reactor 1. Various other wood fractions or additives, such as binders, fire or pest inhibitors, can also be added to the impact reactor 1 as additional material (B) by means of the dosing device 12, as can gut grain 18, which, as will be explained in more detail below, by means of the dosing device 13 is returned to the impact reactor 1 to produce a suitable target grain. For example, a target grain with a high proportion of isolated natural fibers with a length of is for the insulation production 0.5 mm to 3.5 mm and a diameter of 0.02 mm to 0.06 mm are necessary, or fiber bundles are required which consist of three to ten individual fibers of corresponding length. A batch of the impact reactor 1 consisting of the starting materials mentioned takes up between 3% and 6% of the interior 2 of the impact reactor 1.

In the impact reactor 1, an air vortex is now generated with the rotor 4 driven by the drive motor 5, by means of which particles of the charge, in addition to the direct impacts by the rotor 4, are accelerated to speeds between 80 m / s and 130 m / s and comminuted by impact stress ,

The products created as a result of the impact stress can be sucked out of the interior 2 continuously or discontinuously via the suction pipe 3. Since the depth of penetration of the suction tube 3 into the interior 2 is adjustable and since the suction tube 3 can be pivoted or displaced vertically and horizontally, the suction tube 3 can be adjusted such that only products with the desired fiber sizes or fiber qualities are extracted. The pipe dimensions and the design of the discharge opening are other important factors. In a cyclone 14 downstream of the plant 7, these extracted products are separated.

If necessary, products can also be withdrawn discontinuously from the impact reactor 1, collected in a container 15 and fed to a further use, for example a thermal one. It is also possible to return the products A2 via a feed line 16 back into the impact reactor 1.

Following the cyclone 14, the products are conveyed into a further gravity separator 17, such as a zigzag sifter, where they are separated according to the desired target fractions (C). Alternatively, a screening plant can also be used. Oversize is withdrawn from the gravity separator 17 or the screening plant into a container 18 and conveyed back into the impact reactor 1 for further defibration by means of the dosing device 13. The gas stream 23 ′, which can originate from the same source as the gas stream 23, can be fed to the gravity separator 17.

The target fractions (C) are separated again via a further cyclone 19. The resulting target grain can then be fed into a buffer store 20 and then to a dryer 21 via metering. In this, the target grain (C1) is dried to a predetermined final moisture. For this purpose, heat is used, which is obtained in the above-mentioned biomass power plant by burning, for example, the grain fractions 9 and is fed to the dryer 21 by means of the gas stream 23 ″. The target grain (C1) is finally available as a ready-to-use end product, for example in the form of a fiber quantity as the primary or secondary raw material in a bunker 22 of the plant 7. The end product can for example have fibers of 0.5 mm to 2.5 mm in length and a diameter of 20 µm to 60 µm.

If the above and intermediate products (A, B, C) are already dry or dust-forming and therefore explosive, a gas 23 with a low oxygen content, preferably a dry flue gas, is passed into the impact reactor 1 with a suitable temperature as the conveying or intake air , Here is a flue gas side and a heat side Integration in a biomass power plant and in particular in the above-mentioned biomass power plant, in which the grain fractions 9 are burned, is beneficial.

The quality and quantity of the good grain is continuously measured at various points 24, 25, 26 of the system 7. An ultrasonic measuring method is particularly suitable for this. The dosers and thus the filling volume of the impact reactor 1 are regulated by forming a sum from the measuring points 24, 25, 26. The process control is intended to ensure a production process that is as continuous as possible with a corresponding good grain quality.

In the system 7 described, the quality of the fibers produced in the impact reactor 1 depends on various factors, including the piece size, type of wood and the moisture content, as well as the bulk density of the starting materials, the degree of filling of the interior 2, the geometry and the volume of the interior 2 Formation of the rotor 4 and any baffle provided, angles and distances of the rotor 4 from the walls of the interior 2, the centrifugal acceleration of the materials, the feed and discharge elements of the impact reactor 1, the air circulation and flow through the interior 2, and the average distance of particles belong in the interior 2.

It has been shown that the degree of filling of the impact reactor 1 is particularly suitable as a control variable. Filling levels in the range of 3-6% are advantageous.

In the Figure 3 the area of the impact reactor 1 in which the suction pipe 3 projects into the interior 2 thereof can be seen again more precisely. The suction pipe 3 is a pipe which is connected to a suction hose 35. The suction pipe 3 held by a holder 36 penetrates above the bottom 37 of the impact reactor 1, the wall thereof, which comprises a cover plate 38 facing away from the interior 2 and a sieve plate 39 facing the interior 2. In the interior 2, deflector blades 40 are attached to the screen plate 39 adjacent to the suction tube 3 such that the opening of the suction tube 3 is on the lee side of the deflector blades 40 during operation of the impact reactor 1. The deflector blades 40, which are adjustable in height and angle, ensure that no material can inadvertently enter the suction tube 3. Also recognizable in Figure 3 is a further suction pipe 3 ', which is arranged in a region 22 above that region of the interior in which the comminution takes place primarily. Basically, there is the possibility of equipping the impact reactor 1 with both tubes 3 and 3 'or with only one of the tubes mentioned.

Claims (12)

1. Method for producing organic fibrous materials or granular materials, in which a charge comprising at least one fiber-containing organic material is introduced into an interior (2) of a device (1) for crushing materials by means of an impact load and is crushed in this interior (2) by means of impact load, wherein an organic fibrous material or an organic granular material is removed from the interior (2), wherein the removal is carried out by means of an extraction pipe (3) projecting into the interior (2), wherein the extraction pipe (3) is pivotable and/or displaceable perpendicular to a longitudinal axis (6) of the interior (2),
   characterized in that
   the extraction pipe (3) has at least one double-walled portion with injection nozzles.
2. Method according to Claim 1, wherein the fiber-containing organic material is constituted by wood, or by a wood-like material, or by a primary shredder product, or by a residual material from paper production, or by waste paper, or by straw, or by grain husks, or by harvest residues from agriculture, or by green waste, or by a combination of more than one of the aforementioned materials.
3. Method according to one of the preceding claims, characterized in that isolated natural fibers having a length of 0.5 mm to 3.5 mm and a diameter of 0.02 mm to 0.06 mm are obtained.
4. Method according to one of the preceding claims, wherein the relationship between the volume of the charge and the volume of the interior (2) prior to use of the impact load lies below 6% or 5%, or between 3% and 6%, or between 3% and 5%.
5. Method according to one of the preceding claims, wherein the fibrous material or the granular material is removed at least partially by suction from the interior (2) of the device (1), and/or in which the fibrous material and/or the granular material is removed at least partially during operation of the device (1) from the interior (2) thereof.
6. Method according to one of the preceding claims, in which fibrous material and/or granular material is removed from the interior (2) continuously and/or discontinuously.
7. Method according to one of the preceding claims, in which a part of the organic material is removed from the interior (2) and subsequently reintroduced into this.
8. Method according to one of the preceding claims, wherein, as the conveying air or intake air, a gas (23) having an oxygen component of less than 13%, or flue gas, is fed into the interior (2).
9. Method according to one of the preceding claims, wherein the charge is introduced into the interior (2) by means of a mechanical metering device (11).
10. Method according to one of the preceding claims, wherein the fibrous material and/or the granular material is surveyed by means of an ultrasonic or optical process with respect to particle size at discrete moments or continuously.
11. Device (1) for producing organic fibrous materials or granular materials, having an interior (2) for receiving a charge comprising at least one fiber-containing organic material, wherein the device (1) is set up to crush the charge accommodated in the interior (2) by means of an impact load, and wherein the device (1) further has at least one removal device for removing the fibrous material or granular material from the interior (2), wherein
    the removal device has at least one extraction pipe (3) projecting into the interior (2), wherein
    the extraction pipe (3) is pivotable and/or displaceable perpendicular to a longitudinal axis (6) of the interior (2),
    characterized in that
    the extraction pipe (3) has at least one double-walled portion with injection nozzles.
12. Device according to Claim 11, wherein means for the intermittent or continuous surveying of the fibrous material and/or of the granular material with respect to particle size by means of an ultrasonic or optical process are present.

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