DE3315991A1 - Method and device for preparing bulk material with a defined granule distribution of granular sizes - Google Patents

Abstract

Method for preparing bulk material with a defined distribution of granule sizes from damp starting material, the starting material being dried, screened and comminuted and the starting material being simultaneously screened and dried.

Description

Dr. Küttner GmbH & Co. KG ₇ Bismarckstrasse 67, 4300 Essen 1

Process and device for the preparation of bulk material with a defined grain size distribution

The invention relates to a method for preparing bulk material with a defined grain size distribution moist starting material, whereby the starting material is dried, sieved and crushed.

The invention further relates to a device for the preparation of bulk material with a defined grain size distribution from moist starting material with sieves integrated in sieving machines and at least one shredding device attention.

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Bremen / Bremen Office:

P.O. Box 107127
HoHerallee 32, D-2800 Bremen 1
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Accounts Bremen:
Bremer Rank, Bremen
(B! ./. 29080010) 100144 900
Deutsche Bank, Bremen
(BLZ 29070050) 1112002

Bank for Community Economy, Munich
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Munich Office (only Patcmam

P.O. Box / P. C) Box 220137
SchlotthauerstraRe 3, D 8000 Munich 22 Telephone: (089) 2233U
Telescope. / Telecop .: (089) 221569 CCITT 2 Telei'r / Cahli "; Corhonaf Mii" »- h«> n

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An application of the inventive method and the associated device can be used anywhere where a moist initial material is a bulk material is to be produced with a defined grain size distribution. Of course, the application is not to that The enforcement of a moist starting material is limited, but this can also be a dry starting material, as a dry starting material due to the features described below with regard to drying at least not affected.

A specific field of application of the present invention is seen in the preparation of additives for sinter mixes in smelting works. Pain and Very fine-grained ores, the direct smelting of which causes difficulties in the blast furnace, are well known subjected to a sintering process in which individual ore grains are partially melted and caked together a lumpy, present in porous, sponge-like form sintered material is produced. To a desired to achieve a fine distribution of the additives in the fine-grained and very fine-grained ores to be sintered, These additives must also be available in fine and very fine-grained porn, but the desired one Peinst graininess a certain lower limit is thereby set.

The preparation of the ingredients therefore includes in the

Usually a sieving and a crushing carried out, for example, by a roller crusher. Especially with a starting material which has a certain degree of moisture is obtained in this preparation process considerable difficulties. Depending on the mesh size, the sieves settle in the case of moist starting material Sieve very quickly, which can affect the adhesive forces between moist particles of the items to be processed and the surface of a sieve is returned. This has the consequence that a division of the starting material practically no longer takes place depending on the grain size. In the event of a subsequent crushing, for example the output material remaining as sieve overflow becomes output material in such a case subjected to a comminution, which in itself already has the desired grain size.

In order to avoid the difficulties outlined above, one has already resorted to sieving the To forego original goods entirely. However, this leads to the fact that the bulk material after passage through the Comminution process is present with a particle size distribution that has an undesirably high fines content. Furthermore, sieving machines have become known, the sieve bases of which are made of wire mesh are heated, for example inductively, in order to avoid the damp particles of the starting material and the wire mesh in this way counteracting adhesive forces. However, sieve trays of this type only cause partial drying of the particles and only those particles that pass through a sieve. In addition, the par-

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Only start thorough drying when the appropriate Particles of the starting material come into contact with the sieve bottom, so that in the course of time initially, at least for a short period of time, an addition of the sieve results.

In addition, shredding devices have become known in which with the help of a dry Air flow drying of the starting material is carried out and then the ground and dried material sifted and sifted. In this known shredding device there is of course the possibility of setting a desired grain size range precisely through the subsequent sieving, however, is on In this way, through the upstream crushing, part of that grain is also destroyed, which in itself already has the desired size.

Based on the prior art presented above, the present invention is based on the object a process for the preparation of bulk material with a defined grain size distribution from moist starting material indicate that the most problem-free and continuous screening, drying and Enables shredding of the material to be processed.

According to the invention, the object indicated above is first of all and essentially solved in that the starting material is sieved and dried at the same time.

According to the invention it has thus been recognized that a

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The initial material does not necessarily need to be applied after drying, but rather at the same time Drying can be done. The simultaneous Performing the sieving and drying makes it possible to remove those components of the starting material whose Size already lies within the desired grain size distribution, to be sorted out immediately.

The method according to the invention can also be used in be designed in different ways. It is preferably provided that, furthermore, dried and at the same time is comminuted, so that overall screening, drying and comminution of the starting material at the same time expires. It can also be recommended, in particular for the one explained in more detail below Carrying out the drying by means of a gas stream, at the same time as sieving, drying and comminution conduct a sighting.

The starting material can be dried in a number of ways. Conceivable would be z. Legs Drying by radiation or the like. However, it is preferably provided that the drying is carried out by means of a Gas stream is carried out.

The guidance of the gas flow relative to the starting material is essential for effective drying. Advantageous is a guidance of the gas flow at least at an acute angle to the spatial extent of a Sieves. In any case, the aim is to move the starting material and the gas flow in the opposite direction as possible.

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The method according to the invention can also be used in an advantageous manner Wines are carried out in such a way that only a portion of the material to be processed is crushed, namely a (partial) mass flow of the starting material leaving a sieve as a sieve overflow. This becomes the Crushing device supplied only that portion of the starting material, the constituents of which are grain sizes that are above the desired bandwidth. It is preferably provided that a multiple Crushing is carried out and the crushing operations take place one after the other. As functional it has been shown to perform a double crushing.

As has been stated above, the gas flow for drying is at least at an acute angle to the spatial extension of a screen out, at least in such a way that a movement in the opposite direction as possible of the starting material to the drying gas stream takes place. This opposite movement can with regard to the A (partial) mass flow of the starting material passing through a sieve can be implemented in a simple manner in that the gas tronch is essentially perpendicular to the Direction of fall of the material to be processed is guided. This means that the sieves are arranged at an angle at the same time that the gas flow is at an acute angle to the (partial) mass flow moving on a sieve of the initial goods is carried out.

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However, the effectiveness of the drying process will be not only influenced by the main directions of movement of the gas flow and the starting material to each other. Rather, what is decisive is the sequence in which the gas flow and the material to be processed with one another get in touch. On the one hand, the gas stream can be guided in such a way that it initially nit largely dry items to be processed and subsequently in contact with increasingly moist items to be processed comes. In any case, this is an advantageous procedural embodiment if the following described device is used to carry out the method.

As an alternative to this, however, it can also be expedient to initially fill the gas stream with moist material to be processed and subsequently to be brought into contact with increasingly dry material to be processed.

The subject of the invention is largely, as already stated at the beginning, a device for the preparation of Bulk material with defined grain size distribution from moist starting material with integrated in sieving machines Sieves and at least one comminuting device, in particular for carrying out the invention Method in one of the embodiments presented above.

The device according to the invention is first and foremost essentially characterized in that the sieves

are arranged in a cascade on top of each other. The cascade-like arrangement of the sieves on top of one another makes it possible initially a relatively space-saving, high-build version of the device according to the invention, which, however at the same time advantageously accommodates the preparation process to be carried out.

The inventive superimposing of the screens enables a (partial) mass flow of the starting material to be decoupled and recoupled easily, in order to subject it to a crushing process in the meantime, which will be described in more detail below will.

The device according to the invention can in detail be designed in different ways. First of all, it has proven to be expedient to move the sieves spatially to be arranged in such a way that a sieve overflow takes place. This means that the sieves with respect to a Vertical are arranged inclined.

Furthermore, it is preferably provided that the comminuting device is arranged such that it is enforced by a partial flow of the starting material in the bypass is. This arrangement thus uses the advantage described above that a partial flow of the starting material in a simple manner with the cascade-like arrangement of the sieves one above the other with respect to the main penetration direction of the output material is to be decoupled and re-coupled.

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The sieves arranged one above the other in a cascade-like manner are furthermore preferred in the order of penetration of the Output material provided with constant and / or decreasing mesh size. So the initial good is initially subjected to a coarse separation and then to an internal separation that becomes finer. Preferred the mesh sizes of the sieves arranged one below the other are chosen such that the ratio of the The partial mass flow forming the sieve overflow is approximately the same as the partial mass flow forming the sieve passage is.

Furthermore, the mesh size of the starting material is such adapted so that the most favorable possible drying of the starting material particles takes place.

According to the cascade-like arrangement of the sieves and the mesh size decreasing from top to bottom it follows that the starting material passes through the device essentially from top to bottom. Form the device can in any case be selected with a view to a housing comprising the sieves that this housing is designed essentially like a tower. It has proven to be useful to use the shredding device to be arranged outside the tower-like housing.

In detail, the device is also designed so that at least partially baffle pockets below the sieves are provided, on which the sieve pass impacts and on a relatively high point of the downstream

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following arranged, underlying sieve is deflected.

The geometric shape of the sieves is also chosen in such a way that the sieves in a cross section of the Housing this only partially fill. This gives the advantage that the one used for drying Gas flow at the same time enables a sifting of the starting material. Fine fractions of the starting material are floating in the flowing gas stream and are carried away by this, so that the bulk material produced only one Contains a relatively small, negligible amount of fines.

A design in which two comminution devices are provided has proven particularly effective, see above that first a coarse comminution and then a fine comminution can be carried out.

Further details of the present invention result from the subclaims and the following description of an exemplary embodiment.

The exemplary embodiment is explained below using a drawing.

The single figure of the drawing shows a device 3 according to the invention, in which sieves 1 are arranged in a cascade on top of each other.

The screens 1 are at an acute angle with respect to

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arranged a vertical line, so that the output material partially penetrates the sieves 1 as a sieve passage and is partially passed on as a sieve overflow. Impact pockets 5 are provided below the sieves 1 which the sieve pass hits and is deflected in such a way that it hits a sieve arranged below hits a relatively high point.

The exemplary embodiment also has two comminuting devices 2, which are designed as roll crusher in the execution case. A partial flow of the starting material passes through these shredding devices 2 in bypass to the other screens at the same time penetrating remaining partial stream of the starting material.

In the crushing devices 2 only the sieve overflow is introduced via chutes 11, so that only those components of the starting material that exceed a certain size are crushed.

The sieves 1, which are arranged one above the other in the manner of a cascade, are provided with a mesh width such that initially the two first screens 1 in the direction of penetration of the starting material have the same mesh size have and subsequent screens 1 are provided with decreasing mesh size. The breadth of a finger itself is selected according to the resulting ratio of sieve passage to sieve overflow, namely such that the sieve overflow corresponds approximately to the sieve passage.

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As can be seen from the drawing, the starting material is in the upper area of the device 3 via one here input chute 12 shown only as an example. Subsequently, the output material permeates the facility 3 then essentially from top to bottom.

The sieves 1 are arranged in a turn-like housing 4 and the shredding devices 2 outside of this tower-like housing 4, but with this above Chutes 11 connected.

Not shown in the drawing is that the sieves 1 do not completely fill the housing 4 in cross section, so that part of the for drying through the Housing 4 directed gas stream can flow past the side of the sieves 1, which is a simultaneous with the the flowing gas facilitates the desired sighting. As already described above is, in particular particles of the starting material that are smaller than about 0.5 mm from the flowing Gas entrained and discharged from the device 3 upwards.

To feed in and discharge the gas flow used for drying is in the lower area 6 of the housing a gas flow inlet 7 and in the upper region 8 of the housing 4 a gas flow outlet 8 is provided. As from the As can be seen in the drawing, the gas does not only flow through the sieves 1, which are arranged one above the other in a cascade-like manner but also through the crushing devices

Furthermore, the device 3 has a bulk material outlet 10 which is approximately below the comminuting device 2 and is thus arranged outside the housing 4.

The exemplary embodiment shows a device 3 which is designed in particular for the preparation of starting material is, which in the initial state has a grain with a size of up to 30 mm. Accordingly, those of the Initial material initially interspersed with the first two sieves 1 with a mesh size of 10 ran. The first Crushing device 2 is therefore penetrated by a partial mass flow with a grain size of 10 to 30 mm. In the bypass to the partial mass flow passing through the first shredding system 2 the remaining partial mass flow of the starting material passes through two sieves 1, the first of which is one Mesh size of 8 and the second has a mesh size of 6 nm. The following are the two partial mass flows reunited and first pass through a sieve 1 with a mesh size of 4 mm and then a sieve 1 with a mesh size of 3 nm. The sieve overflow of the sieve 1 with the mesh size 3 mrn is the second shredding device 2 supplied. The partial mass flow fed to the second shredding device 2 accordingly has a grain size of 3 to 10 mm. Immediately in front of the gas flow inlet 7 is still a sieve 1 with a mesh size of 0.5 mm is arranged, the sieve overflow together with the second crushing device 2 penetrating

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Partial wet stream is brought together and the end product emerging from the bulk material outlet 10 results.

The features of the invention disclosed in the above description and in the following claims can be used both individually and in any combination for the implementation of the invention in their various embodiments may be essential.

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K 997

May 3, 1983

List of reference symbols

Sieve

2 shredding device 2 3 establishment 3 4 housings 4th 5 impact pocket 5 6 lower area (of 4) 6th 7 gas flow inlet 7th 8 upper area (of 4) 8th 9 gas flow outlet 9 10 bulk material outlet 10 11 chute 11th 12 feed chute 12th

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Claims (1)

K 997 May 3, 1983 Expectations 1. A method for the preparation of bulk material with a defined grain size distribution from moist starting material, wherein the starting material «is dried, sieved and comminuted, characterized in that the starting material sifted and dried at the same time. 2. The method according to claim 1, characterized in that the starting material continues to be dried at the same time and is crushed. 3 · Method according to one of claims 1 or 2, characterized marked, ate the original material sighted at the same time will. 4. The method according to any one of claims 1 to 3, characterized characterized in that the starting material is dried in a gas stream. BOKHM £ ^£> T SBCWFfVJTeRT 5. The method according to any one of claims 1 to 4, characterized characterized in that the gas stream is guided at an acute angle to the spatial extent of a sieve will. 6. The method according to any one of claims 1 to 5, characterized in that only a subset of the material to be processed is crushed. 7. The method according to any one of claims 1 to 6, characterized in that only one as a sieve overflow Mass flow of the starting material leaving the sieve comminuted will. 8. The method according to any one of claims 1 to 7, characterized in that multiple comminution is carried out will. 9. The method according to claim 8, characterized in that
that the comminution processes are carried out one after the other. 10. The method according to any one of claims 1 to 8, characterized in that a double size reduction is carried out will. 11. The method according to any one of claims 4 to 10, characterized characterized in that the gas stream is guided essentially perpendicular to the direction in which the material to be processed falls will. BOEHMfcRT & "BOEB \ T £ RT.". *. . 3. 12. The method according to any one of claims M to 11, characterized in that ^ _a ß ^ _he gas stream is guided in such a way that it can initially come into contact with largely dry material to be processed and subsequently with increasingly moist material to be processed. 13 · The method according to any one of claims 4 to 11, characterized characterized in that the gas stream is guided in such a way that it is initially filled with dry material to be processed Touch comes. 14. Device for the preparation of bulk material with a defined grain size distribution from moist starting material with sieves integrated in sieving machines and at least one comminution device, in particular for Implementation of a method according to one of Claims 1 to 13, characterized in that the sieves (1) are arranged in a cascade on top of each other. 15. Device according to claim 14, characterized in that that the at least partial sieves (1) are provided with such a spatial extension that a sieve overflow takes place. 16. Device according to one of claims 14 or 15, characterized in that the comminuting device (2) is arranged in such a way that it can be penetrated by a partial flow of the starting material in the bypass. 17. Device according to one of claims 14 to 16, there- BORHMKRT characterized in that the sieves (1) have a point in their spatial extension with a perpendicular Include angles. 18. Device according to one of claims 14 to 17, characterized characterized in that the sieves (1) in enforcement sequence of the starting material with constant and / or decreasing mesh size are provided. 19 · Device according to claim 18, characterized in that that the mesh size increases according to the ratio of a partial mass flow forming the screen overflow a partial mass flow of the starting material forming the passage through the sieve is selected. 20. Device according to claim 19, characterized in that the ratio of sieve overflow to sieve passage is chosen such that the sieve overflow is equal to the sieve passage. 21. Device according to one of claims 14 to 20, characterized in that at least those in the enforcement sequence of the starting material first two sieves (1) are provided with the same mesh size. 22. Device according to one of claims 14 to 21, characterized characterized in that the device (3) of the output material essentially from top to bottom is enforce. 23. Device according to claim 22, characterized BOEUMfcrcr. &: BQEMM mT: ** :. ": _ -" _r - - _Λ net, that the sieves (1) are in an essentially tower-like manner Housing (4) are arranged. 24. Device according to claim 23, characterized in that that the shredding device (2) are arranged outside the tower-like housing (4). 25 · Device according to one of claims 14 to 23, characterized characterized in that baffle pockets (5) are provided at least partially below the sieves (1). 26. Device according to claim 24, characterized in that that the impact pockets (5) are provided with such a spatial extension that only the passage through the sieve hits the impact pockets (5). 27. Device according to one of claims 14 to 26, characterized in that the sieves (1) have a cross section of the housing (4) only partially fill out. 28. Device according to claim 27, characterized in that a in the lower region (6) of the housing (4) Gas flow inlet (7) and a gas flow outlet (9) is provided in the upper region (8) of the housing (4). 29. Device according to one of claims 14 to 28, characterized in that two comminuting devices (2) are provided. 30. Device according to one of claims 14 to 29, characterized in that a bulk material outlet (10) BOEHMnRT & -BCSEHMBRT - "-". is provided. 31. Device according to claim 30, characterized in that that the bulk material outlet (10) is arranged outside the housing (4).