EP1248880A1

EP1248880A1 - Method and device for sorting a mixture of paper

Info

Publication number: EP1248880A1
Application number: EP00988574A
Authority: EP
Inventors: Clemens Lenzen; Jürgen Hüskens; Gerd Buchholz
Original assignee: Isis Servicegesellschaft fur Planung und Instandhaltung Von Entsorgungs- und Industrieanlagen GmbH; Isis Servicegesellschaft GmbH; RWE Umwelt Engineering and Service GmbH
Current assignee: Remondis Energy and Service GmbH
Priority date: 1999-11-12
Filing date: 2000-11-10
Publication date: 2002-10-16
Also published as: AU2501701A; WO2001036739A1; DE10083527D2

Abstract

The invention relates to a method for sorting a mixture of paper, according to which the mixture is shredded to a particle size in the range of between 20 and 80 mm and the shredded mixture is then separated using an air separator at a separation speed of between 1 and 5m/sec into a heavy fraction containing a mixture of paper and a light fraction containing deinking material. The invention aims to produce a high-quality fraction of commercial waste paper and a high-quality fraction of deinking material in a cost-effective manner. To this end, the paper is sieved using a sieve-hole size of between 200 and 450 mm before being shredded, in order to separate a coarse fraction containing large pieces of cardboard. The invention also relates to a device for sorting a mixture of paper comprising a shredder (2) for shredding the mixture and an air separator(3) connected downstream of the shredder (2) for separating the shredded mixture of paper into a heavy fraction and a light fraction. The air separator (3) has a separation cross-section, in which a separation speed of between 1 and 5 m/sec can be set. The invention achieves the aim of producing a high-quality fraction of commercial waste paper and a high-quality fraction of deinking material in a cost-effective manner by the positioning of a sieve (1) upstream of the shredder (2), for separating a coarse fraction containing large pieces of cardboard, said sieve having a sieve-hole size of between 200 and 450 mm.

Description

Method and device for sorting a paper mixture

The invention relates to a method according to the preamble of claim 1

Sorting of a paper mixture, in which the paper mixture is crushed to a grain size in the range of approximately 20 to 80 mm and the shredded paper mixture is separated by means of wind sifting at a separation speed of between 1 and 5 m / sec into a heavy material fraction containing mixed paper and a light material fraction containing deinking The invention further relates to a device according to the preamble of claim 11 for sorting a paper mixture with a shredder for shredding the paper mixture and a waste classifier connected downstream of the shredder for separating the shredded paper mixture into a heavy material fraction and into a light material fraction, the water separator having a sighting cross-section, in the a separation speed between 1 DIS 5 m / sec adjustable

In Germany, around 12 million t / a of waste paper is currently being used again in production processes. Of this amount, around 5.3 million t / a is again sorted into various types in numerous facilities before being recycled

In facilities and methods known in practice for sorting the collected paper mixtures, sorting staff is used to separate the contents of depot containers, bulk bulk goods and / or bundle bulk goods into different qualities and the paper / cardboard qualities required for reuse, including demking. Quality to be achieved Devices for sorting a paper mixture generally comprise conveyor belts or sorting belts with sorting staff, which are used to produce a demking quality from the paper mixture supplied Storages such as cardboard, cardboard and possibly books as well as non-paper components are sorted out by hand, among other things. With this known sorting, cardboard and cardboard are selected to produce a fraction that mainly contains cardboard

A deinking fraction, a mixed paper fraction and a cardboard fraction are obtained in this way. The deinking fraction consists largely of newspapers and magazines and, as required, has at least 60% newspapers and a proportion of contaminants, e.g. cardboard, cardboard and non-paper components, of a maximum of 3% , while the fraction of mixed paper, newspapers and magazines (less than 40%), cardboard, other papers, cardboard (over 60%) and to a lesser extent contains plastics and other storage materials. The cardboard fraction mainly consists of cardboard (over 70%), Cardboard boxes, solid cardboard and the like

DE-A-25 42 571 describes a method for sorting waste paper, in which the waste paper is placed directly in a shredder and the shredded waste paper is split into three fractions by means of two air separators connected in series. Here it is provided that the shredded waste paper is loosened in the first water separator and to split off a first heavy fraction, which contains cardboard, cardboard boxes and heavy kraft paper, which is highly enriched. The remaining light fraction from the first water classifier is then fed to the second water classifier and into a second heavy fraction, which contains cardboard boxes, cardboard boxes and heavy kraft paper, highly enriched, as well as in a light fraction, which contains magazines, newspapers and other press papers, enriched, separated. The speeds of the wind separations are high, since heavy waste materials such as metals, sand, glass etc. are contained in the collected waste paper nd small parts get into the first and second heavy goods, so that these heavy goods fractions and thus a considerable part of the waste paper used are not considered to be of higher quality Waste paper types are marketable There is also a risk that shredded catalog prints, which are held together by glue or staples, will get into the first and / or second heavy fraction and limit their marketability as waste paper for the department store (type B 19) a department store paper

Fraction from The proposed loosening and deagglomeration by means of the first air classifier in principle enables effective sorting in the second air classifier, but requires a high level of energy consumption due to the high air flows and leads to relatively high wear due to the high air speed and the contaminants. In addition, the grain size is accordingly the diagonals of the 10x10 edges of the shredding 141 mm, whereby widespread small cardboard boxes as a whole are processed without being shredded

Internationally unpublished patent application PCT / EP99 / 03576 describes a method and a device which shred the paper mixture to a grain size in the range of approximately 40 to 100 mm and the shredded paper mixture by means of wind sifting at a separation speed between 1 to 5 m / sec in separating a heavy material fraction containing mixed paper and a light material fraction containing deinking. In addition, it is proposed to precede the shredding of the paper mixture with a loosening stage and a screening

DE-A-25 42 571 describes a method and a system for sorting and processing waste paper, in which the material fed is divided into three fractions, which are subsequently characterized in more detail by means of color detection. A blower is used for ejection, but it does not perform wind separation

DE-A-25 10 694 describes a process for the selection of papers, in which waste containing paper is ground and after separation in one The material is separated and a light material fraction is subsequently moistened and thereby separated again. Particularly pure demilgment qualities cannot be achieved with this technology

It is the object of the invention to provide a method according to the preamble of claim 1 and a device according to the preamble of claim 11, respectively, by means of which a high-quality fraction of department store paper and a high-quality fraction deinking can be produced in a cost-effective manner

This object is achieved in the method mentioned at the outset with the characterizing features of claim 1 in that the paper mixture is sieved before shredding to remove a coarse fraction containing large cardboards with a sieve hole size of approximately 200 to 450 mm mentioned device erfmdungsgemaß solved with the characterizing features of claim 11 in that the shredder is preceded by a sieve for separating a large cardboard-containing coarse fraction with a sieve hole size of about 200 to 450 mm

With the method and the device according to the invention, a high-quality fraction of department store paper (type B 19) and a high-quality fraction deinking can be produced in a cost-effective manner

With a sieve with a sieve hole size of approximately 280 to 400 mm, a particularly high-quality fraction of department store paper can be produced and the quality requirements for the deinking fraction can be met particularly reliably

In their combination, screening with the specified screen hole widths enables the waste paper to be shredded to the recommended size Grain size and the wind sifting at such a separation speed also high throughput with a consistently high quality of the fractions produced

In a particularly advantageous manner, the paper mixture is sieved and loosened by means of a ballistic separator provided with sieve openings. A suitable ballistic separator essentially comprises a plurality of flat profiles which are arranged next to one another at an incline and which can be moved horizontally and vertically, for example by means of a crankshaft drive, and - in contrast to ballistic separators known from density classification or sorting - are provided with through-openings for sieving.

A particularly productive wind sifting takes place after crushing to a grain size in the range of about 40 to 90 mm

When the paper mixture is shredded to a grain size in the range of about 30 to 60 mm, a particularly high quality of separation between mixed paper and deinking can be achieved with a relatively small amount of shredding. With this grain size, the cardboard contained in the shredded paper mixture can be more than 95% separate and largely enrich in the heavy goods fraction Furthermore, with a shredding to these grain sizes, the white potential of stapled or glued papers for the deinking fraction can still be developed with a reasonable amount of shredding. If you shred to a grain size of less than 50 mm, it can be avoided that on them Folded pieces of newspaper and larger pieces of magazines and catalogs with their relatively high proportions of white, due to the presence of glue points and staples, can reach all heavy items rad and achieve a high degree of freedom from adhesive backing of the deinking fraction Crushing below the proposed limits, adhesive components increasingly came into the deinking fraction and further processing of the deinking fraction became more difficult. In addition, the technical and economic expenditure on crushing was increased

If the separation speed is in the range from 1.5 to 4.5 m / sec, preferably in the range from 1.7 to 3.5 m / sec, particularly high qualities can be ensured in the fractions produced

If the wind sifting is carried out in a cone sifter, largely trouble-free operation, good separation performance and a high throughput can be guaranteed. A suitable air sifter is known, for example, from DE-U-297 09 918. If the wind sifting takes place in a zigzag sifter, one can Particularly high separation sharpness between mixed paper and deinking can be achieved if the wind sifting takes place in a cross-flow sifter, particularly trouble-free operation can be ensured

The shredded paper mixture is fed into the air classifier in a particularly advantageous manner by means of a rotary valve, provided that it is designed as a conical or cross-flow classifier. In order to ensure trouble-free supply and continuous loading of an air classifier designed as a conical classifier, the rotary valve is preferably eccentric in the feed channel arranged of the air classifier

The shredded paper mixture is preferably mechanically conveyed to the air classifier. If the mechanical requirement comprises a conveying device designed as a paddle screw, pieces of paper that are connected at their kinks or folds can be gently dissolved without causing more violent tears. which are held together by adhesive, torn apart and deinking into the fraction advised where, however, they are undesirable due to their adhesive content and associated processing difficulties. The mechanical conveying further preferably includes vibrators for feeding into the air classifier or for feeding to a cellular wheel sluice.

The light material fraction that initially arises during wind sifting and contains the deinking fraction is advantageously split into the (conveying) air stream and deinking in a separating cyclone.

The quality of the deinking fraction, in particular the degree of whiteness, can be increased by presorting the paper mixture to be fed to the shredder by means of color and / or NIR (near infrared) detection and pneumatic discharge of identified contaminants. For example, through-colored papers can be separated early and effectively on the basis of their size and / or coloring, so that deinking and mixed paper fractions freed from through-colored papers can be produced.

Further advantages and features of the invention emerge from the following description and from the dependent claims.

The invention is explained in more detail below with reference to the attached drawing using a preferred exemplary embodiment of a device according to the invention for sorting a waste paper mixture from a barrel collection.

1 shows a schematic representation of an exemplary embodiment of a device according to the invention for sorting a waste paper mixture The device for sorting a waste paper mixture shown schematically in FIG. 1 comprises a sieve designed as a ballistic separator 1, a shredder designed as a granulator 2, a wind sifter designed as a cone sifter 3, which is connected downstream of the granulator 2, and a cyclone 4 connected downstream of the cone sifter 3 2 has, as a crushing means, blow bars arranged distributed over the circumference and in the axial direction of a rotor, which, in cooperation with an associated stator, bring about a low-dust cutting and shearing crushing without squeezing the paper mixture into other shredder blocks which are otherwise different the granulator 2 by means of a sieve arranged below the rotor with a corresponding sieve opening and a return of the material which has not yet been sufficiently comminuted into the engagement area of the rotor

When designing the shredder 2, it is essential that the shredding means prevent several sides from sticking together during the shredding, so that, at most, small pieces of paper sticking to one another, for example by block-like punching, are produced a hammer mill is also suitable, in which a relatively high level of dust can possibly be accepted

A filter 5 for separating dust from the carrier air is arranged downstream of the cyclone 4. A color sorting device 7 is connected between the ballistic separator 1 and the granulator 2, which separates colored paper components, for example colored papers, depending on the amount or amount of colored waste paper and the desired one The white sorting device 7 can be omitted if necessary Between the pelletizer 2 and the cone sifter 3, a conveyor device designed as a paddle screw 6 for conveying and loosening up the shredded paper mixture is arranged.

An FE separator 8 with a downstream baler 9 is arranged downstream of the cone sifter 3 on the output side of the heavy material or the mixed paper fraction.

For processing or sorting, the waste paper mixture delivered via a barrel collection is sieved and loosened by means of the ballistic separator 1 and fed to the granulator 2, where it is crushed to a grain size of approximately 35 mm. The sieving by means of the ballistic separator 1 separates approximately 10 to 25% of the paper mixture fed in as the upper run, which essentially comprises larger cardboards and already has the quality of department store paper (type B 19).

If the color sorting device 7 is connected between the ballistic separator 1 and the granulator 2, the through-colored papers are separated in this.

The shredded and possibly freed of colored constituents waste paper mixture is then conveyed into the conical sifter 3 by means of the paddle screw 6 and vibrators (not shown) and there is split into a heavy goods fraction and a light goods fraction by means of an air flow (carrier air), the speed of the air flow in is set to about 3 m / sec. The heavy-duty fraction is the mixed paper fraction, which largely consists of lumpy cardboard / cardboard and other shreds of paper and a small proportion of other contaminants, as well as meeting the requirements for sorted mixed waste paper, a lower grade (grade B 12). The light material fraction comprises the deinking fraction and the conveying air flow. In the wind sifting, they are in the shredded paper mixture contained cardboard-containing components to more than 95% separated and enriched in the mixed paper fraction

While the mixed paper fraction is freed of magnetic storage substances by the metal separator 8 and pressed into bales by means of the baler 9, the light material fraction is fed to the cyclone 4 and separated there in deinking and air flow. The cyclone 4 is advantageously designed as a sifting cyclone with which in one process step or with one device, the deinking fraction can be separated from the carrier air and, at the same time, dust can be removed

The air flow is then fed to the filter 5 and dedusted there

In order on the one hand to obtain a good opening section in the wind sifting and on the other hand to ensure a high throughput, the conical sifter 3 has a sifting cross section of approximately 0.01 to 0.4 m ² , preferably 0.05 to 0.3 m ^2, to the volume flow Air is adjusted in such a way that a separation speed of approximately 1 to 5 m / sec, preferably 1.5 to 4.5 m / sec and particularly preferably 1.7 to 3.5 m / sec results in order to achieve a sufficient throughput with the To ensure device, several air classifier 3 and shredder 2 are connected in parallel

After the shredder 2, cone sifter 3 and cyclone 4 had run through, approximately 40.5% of mixed paper and approximately 59.5% of deinking, based on the waste paper mixture fed to shredder 2, were obtained in an experiment. The deinking fraction consists of significantly more than 97.5% made of thin paper and has only a small proportion of thin cardboard and other storage materials

In an experiment in which the cone sifter was replaced by a zigzag sifter, approximately 36% of mixed paper and approximately 64% were obtained Deinking based on the waste paper mixture fed to the shredder 2

At the specified separation speeds, the amount of contaminants in the deinking fraction, which significantly reduces the quality of the papers made from deinking, such as cardboard, adhesive backing wrapping papers and colored papers, were below 1.5% (mass% based on the input of the shredder)

10 storages which are excreted as rejects in a further processing of the deinking fraction in a paper mill, e.g. B Plastics and wet-strength papers were below 1% (mass% based on the input). In comparison to known processes and equipment, the storage materials can have a negative influence on the quality of the deinking fraction produced using the process according to the invention or the device according to the invention be reduced by over 30%

In a modification of the configuration described above, the device can be provided with a wave screen in order to automatically separate large cardboards 20 and to produce a high-quality fraction of cardboard in an economical manner

A training of the sieve as a ballistic separator 1 has the advantage, however, that in addition to the sieve function, it is also counteracted by a certain cyclic beating

25 the feed material takes on a loosening function and thus ensures that the shredder 2 is fed with individual or loose sheets as possible, so that no crushing of a multilayer newspaper / magazine can take place at the cut edges during the shredding. Such loosening significantly increases the yield of deinking

30 If the loosening function is dispensed with, one has to accept a correspondingly lower yield, since they may then be together compressed paper chips would get into the heavy goods, or if necessary provide a separate loosening device.

If the wind sifting is carried out by means of a cross-flow classifier in a modification of the abovementioned tests or the above exemplary embodiment, a compact design of the wind sifting stage can be achieved with little investment. In a cross-flow sifter, the shredded paper mixture can advantageously be separated in free fall and any baking of wet pieces of paper on internals can be avoided.

In a particularly advantageous embodiment of the method or the device, the paper mixture is sieved in two stages. Here, the sieve designed as a ballistic separator 1 can be designed in two stages. A particularly expedient ballistic separator 1 can for this purpose have an essentially sawtooth-shaped profile with two successive areas of different sieve hole widths. In a first area, the screen hole width is approximately 40 to 60 mm. In a second area, the screen hole size is approximately 200 to 450 mm, preferably 280 to 400 mm. In the event that sieving is carried out with a two-stage sieving, it is advantageous to direct the underflow directly into the air classifier 3. Such screening also leads to an additional loosening of the feed material, which is virtually transported over the first area and thus also contributes to an increase in the deinking yield.

Claims

Process for sorting a paper mixture, in which the paper mixture is shredded to a grain size in the range of approximately 20 to 80 mm and the shredded paper mixture is separated by means of wind sifting at a separation speed of between 1 and 5 m / sec into a heavy goods fraction containing mixed paper and a light goods fraction containing deinking is characterized in that the paper mixture is sieved with a sieve hole size of about 200 to 450 mm prior to shredding to separate a coarse fraction containing large cardboard

A method according to claim 1, characterized in that the paper mixture is sieved with a sieve hole size of about 280 to 400 mm before shredding

A method according to claim 1 or 2, characterized in that the paper mixture is sieved and loosened by means of a ballistic separator before comminution

Method according to one of claims 1 to 3, characterized in that the paper mixture to a grain size in the range of about 30 to

60 mm is crushed

Method according to one of claims 1 to 4, characterized in that the separation speed is 1.5 to 4.5 m / sec, preferably 1.7 to 3.5 m / sec

Method according to one of claims 1 to 5, characterized in that the wind separation is carried out by means of a cone sifter Method according to one of claims 1 to 5, characterized in that the wind separation is carried out by means of a zigzag sifter or a cross-flow sifter

Method according to one of claims 1 to 7, characterized in that the shredded paper mixture is fed into the wind sifting by means of a cellular wheel sluice or a vibrating can

Method according to one of claims 1 to 8, characterized in that the shredded paper mixture is demanded by means of a mechanical conveying device for air separation

Method according to one of claims 1 to 9, characterized in that the light material fraction from the wind sifting by means of a

Separation cyclones into the deinking fraction and the air flow is split and dedusted

Device for sorting a paper mixture with a shredder (2) for shredding the paper mixture and one with the shredder

(2) downstream air classifier (3) for separating the shredded paper mixture into a heavy material fraction and into a light material fraction, the air classifier (3) having a viewing cross-section in which a separation speed between 1 to 5 m / sec can be set, characterized in that Chopper (2) is preceded by a sieve (1) for separating a coarse fraction containing large cardboards with a sieve hole width of approximately 200 to 450 mm

Device according to claim 1 1, characterized in that the

Sieve hole width is approximately 280 to 400 mm 13 Device according to claim 1 1 or 12, characterized in that the shredder (2) is designed as a granulator of the hammer mill

14 Device according to one of claims 1 1 to 13 characterized - in that the sieve (1) is designed as a ballistic separator

15 Device according to one of claims 1 1 to 14, characterized in that the shredder (2) with shredding means for shredding to a grain size in the range of about 120 to 80 mm,

10 is preferably 30 to 60 mm

16 Device according to one of claims 1 1 to 15, characterized in that the air classifier (3) is designed as a cone classifier

ι_> 17 Device according to one of claims 1 1 to 15, characterized in that the air classifier (3) is designed as a zigzag classifier or cross-flow classifier

18 Device according to one of claims 1 1 to 17, characterized 20 in that the air classifier (3) is designed as a conical classifier and has a cellular wheel sluice arranged eccentrically in the entrance area

19 Device according to one of claims 1 1 to 18, characterized 2 ^ characterized in that between the shredder (2) and the

Wmdsichter (3) a mechanical conveying device (6) is provided

20 Device according to claim 19, characterized in that the mechanical conveying device (6) is designed as a Ford screw

^ o

21 Device according to one of claims 1 1 to 20, characterized in that the air classifier (3) has a separating cycle (4) for Separation of the deinking fraction from the light material fraction and dedusting of the light material fraction is connected downstream.

22. Use of a device according to one of claims 1 1 to 21 for sorting a paper mixture, in particular a waste paper mixture from the paper collection.