EP0727256A1 - Method and device for milling humid mineral material - Google Patents

Abstract

The pulverizing material is exposed inside the material bed pulverizing machine and directly after leaving the pulverizing zone to a fluid injection spray (11') which has an at least partial de- agglomerating effect. The fluid supplied is then fed with the pulverizing material to the wet grading area (6'). The pulverizing product leaving the pulverizing zone can be additionally subjected to mechanical de-agglomeration. The fluid is sprayed in under a minimum pressure. The fluid can be injected into the area immediately after the pulverizing zone to flush away material particles from the inside walls and machine parts.

Description

The invention relates to a method according to the preamble of claim 1 and a device according to the preamble of claim 6 and is designed for comminution of moist mineral material.

Methods and devices of the required type are known in practice in various embodiments. For example, they can be used for the comminution of moist, in particular earth-moist or naturally moist raw materials and similar moist goods in the cement, lime and gypsum industries, but also for the processing / comminution of ore materials.

In this context, it is already known, for example from DE-C-38 22 729, to crush relatively brittle mineral material in a bed-type roller mill, from which the crushing product obtained at least partially in the form of approximately flat agglomerates or scraps is fed to a screen classifier . Here, a pulping device is arranged between the roller mill and the screen classifier, which is divided into an inlet section with liquid supply devices for the agglomerates and the liquid and a swirling section, at the lower end of which a feed pump for the suspension of liquid and deagglomerated comminution product is provided. The agglomerate feed device of the feed section is designed in a chute-like manner and arranged under the material bed roller mill, and it opens into a feed channel to which a liquid feed device is connected is connected in the manner of a motive water injector and connects the inlet section to the inlet of the swirling section.

The invention is based on the object of creating a method according to the preamble of claim 1 and a device according to the preamble of claim 6 which, with reliable operation and particularly good deagglomeration effect, enable a relatively simple and compact device structure.

This object is achieved on the one hand - procedurally - by the characterizing part of claim 1 and on the other hand - in terms of the device - by the characterizing features of claim 6.

Advantageous embodiments of the invention are the subject of the dependent claims.

While in the state of the art described above, the comminution product coming from the material bed comminution machine is fed via an agglomerate feed device to the feed section of a digestion device and from there is introduced into a swirling section in order to be deagglomerated before the classification process, the present invention is completely different Path. According to the invention, namely, the comminution product coming from the material bed comminution machine is still exposed to a liquid injection with at least partial deagglomeration effect within the product bed comminution machine and immediately after leaving the comminution zone, and this supplied liquid is then, together with the comminution product, then preferably immediately afterwards, passed to the wet classification. This results in an extremely advantageous way of designing or designing the entire comminution device for the moist mineral material in an extremely compact manner. By adding or injecting liquid, preferably water, the agglomerates or flakes of the comminution product can be dissolved very effectively and, if necessary, also extremely gently, or disagglomerated, by the manner in which the injection can be easily influenced.

Especially in the case of agglomerates which are relatively difficult to dissolve, the comminution product leaving the comminution zone can also be subjected to mechanical deagglomeration in addition to the liquid injection. In this way, a very specifically targeted disagglomeration effect can be achieved, with the additional possibility of influencing this disagglomeration effect by appropriately controlling the liquid injection and / or by appropriately designing and controlling appropriate mechanical dissolving devices to disagglomerate the comminution product. It can be particularly advantageous if the liquid is injected with a minimum pressure and possibly also a specially selected high pressure.

In this method according to the invention, it is also of particular advantage if the liquid is injected into the region immediately downstream of the comminution zone in such a way that walls and are present in this interior region of the material bed comminution machine Machine parts of good particles of the comminution product are washed away. Within the shredding machine, sticking, caking, clogging or the like can be avoided with good reliability by good particles of the shredding product.

In a further advantageous embodiment, it can be ensured that the comminution product is separated into a fine material to be removed (generally in the form of fine material sludge) and into a coarse material to be re-fed to the material bed comminuting machine or its inlet during the wet classification. A minimum fineness of the fine material to be removed can be guaranteed by such a recirculation of material that has not yet been comminuted sufficiently.

The device for comminuting moist mineral material is characterized according to the invention in that a disagglomeration zone is formed within the material bed comminution machine and - viewed in the direction of material flow - immediately behind the grinding gap, in which an at least partial deagglomeration of the comminution product is provided and the the wet classifier is directly subordinate. With this compactly designed shredding device, the shredding of moist, in particular earth or naturally moist mineral material can be carried out particularly reliably in the manner explained above.

Fig. 1

eine teilweise schematisch gehaltene Vertikalschnittansicht eines ersten Ausführungsbeispieles der erfindungsgemäßen Vorrichtung;

Fig. 2

eine schematische Vertikalschnittansicht durch ein zweites Ausführungsbeispiel der Vorrichtung.

The invention is explained in more detail below with reference to the drawing. Show in this drawing

Fig. 1

a partially schematic vertical sectional view of a first embodiment of the device according to the invention;

Fig. 2

is a schematic vertical sectional view through a second embodiment of the device.

In both of the exemplary embodiments illustrated, the device is used for comminution, in particular commodity bed comminution of moist mineral material of the type explained at the beginning.

In the first exemplary embodiment illustrated in FIG. 1, the device contains a material bed comminution machine 1 with a material inlet 1 a, which can preferably be equipped in the form of a feed shaft or the like and to which the material to be comminuted is fed in accordance with the arrows 2, 3. The material bed shredding machine 1 has a machine housing 4. Within this machine housing 4 and thus also within the material bed comminution machine 1, a deagglomeration device 5 is provided for dissolving agglomerates formed during the material bed comminution, which will be discussed in more detail later. Connected to this deagglomeration device 5 is a wet classifier 6, which is only indicated schematically in FIG. 1 and, in this example, is arranged directly below the material bed comminution machine 1 and, if necessary, can also form a structural unit with this product bed comminution machine 1.

The material bed comminution machine 1 also contains a comminution zone which - as will be explained in detail later - by a grinding gap 7 between two grinding surfaces 8, 9 pressed against one another at high pressure is formed. Immediately behind this grinding gap 7, a disagglomeration zone 17 is formed with the disagglomeration device 5 already mentioned, as viewed in the direction of flow (arrow 10). In this deagglomeration zone 17, at least one liquid injection device is now provided, which primarily contains a number of liquid feed pipes 11 distributed in this deagglomeration zone 17, which form an essential part of the deagglomeration device 5. These liquid supply pipes 11 are preferably connected to a control device 12, only indicated schematically, for setting the respectively desired liquid pressure. The injection pressure for the liquid, which is preferably water, can be selected so that an at least partial deagglomeration of the comminution product from the material bed comminution can be achieved by means of this liquid injection device. The largely or completely deagglomerated or dissolved comminution product then flows downward via connecting lines (or pipes) 13 into the directly downstream wet classifier 6 or arranged below the material bed comminution machine 1.

The material bed shredding machine 1 according to this first exemplary embodiment illustrated in FIG. 1 can in principle be constructed in accordance with the embodiment described in DE-A-42 27 188. Accordingly, this material bed comminution machine 1 can have the following features in particular: a fixed first grinding track 8, which is arranged essentially horizontally in the machine housing 4 and which is the forms an above-mentioned grinding surface, furthermore a second grinding path 9, which can wobble relative to the first grinding path 8 and forms the second above-mentioned grinding surface, furthermore a driven swash plate 14 for producing a wobbling movement of the second grinding path 9, through which the width of the between the two grinding paths 8, 9 formed grinding gap 7 periodically enlarged and reduced, both grinding tracks formed as a substantially flat ring tracks and inclined at a flat angle to each other, the swash plate 14 carries a cover 15 surrounding it, through which the grinding gap 7 in a larger the gap area Wide peripheral circumferential zone is covered towards the outside and the regrind 2, 3 to be comminuted is fed to the grinding gap 7 from the radially inner circumference and the comminuted regrind or comminution product (arrows 16) is discharged to the outside via the outer circumference of the grinding gap 7. Accordingly, the deagglomeration zone 17 is formed in an annular space which is located approximately in the area between the two grinding tracks 8, 9 and the inner circumferential side 4a of the machine housing 4 or is limited by these parts. In this annular space or in this deagglomerating zone 17 is the deagglomerating device 5 already mentioned above, which, in addition to the liquid injection device with the liquid supply pipes 11, also contains a mechanical deagglomerating device, for which at least partially non-rotatably provided in the outlet area of the grinding gap 7 associated with the swash plate 14 and approximately strip or club-shaped deagglomerating elements 18. These disagglomerating elements, which are movably arranged in the said annular space, can interact with similar or suitable further deagglomerating elements. which can, for example, be fixed on the inner circumferential side 4a of the machine housing. There is no danger that the disagglomerating elements 18 will be glued by good particles or be occupied in any other way, or that even a blockage of good could occur in this area, insofar as through the liquid supply pipes 11, i.e. through the liquid injection device, also for one at the same time Flushing of all internals in the area of the deagglomeration zone 17 is ensured.

The wet classifier 6 arranged immediately below the material bed shredding machine can in principle be designed in any suitable and expedient manner. In this exemplary embodiment illustrated in FIG. 1, the wet classifier 6 is provided with a liquid trough 19, with a fine material outlet 21 arranged in the region of the liquid level 20 in this trough 19, further with a conveying element 22 arranged in the bottom region of the liquid trough 19, and with one at one end thereof Conveying device 22 provided coarse material outlet 23. The conveying member 22 can expediently be designed as a suitable conveying screw (as shown in FIG. 1), so that the wet classifier 6 is designed approximately in the form of a screw classifier, the conveying screw 22 of which is arranged at the bottom of the liquid trough, conveying obliquely upwards to the coarse material outlet 23. While the fines to be drawn off through the fine material outlet 21 are discharged as finished goods or other goods to be processed in accordance with arrow 24, a recirculation conveyor device, which is symbolized only by a schematically indicated line 25, is provided for the coarse goods to be removed at the coarse material outlet 23, which rejects the coarse material outlet 23 connects to the inlet la of the material bed shredding machine 1, so that this coarse material (arrow 3) can be fed to the shredding machine 1 again. The exemplary embodiment of the comminuting device illustrated in FIG. 1 and described above shows without further ado that this comminuting device has an extremely compact design, in particular in the area of the material bed comminuting machine 1, and can ensure a particularly good deagglomeration effect with reliable operation.

In principle, however, the material bed comminution machine can also be designed differently, for example according to the principle of a material bed roller mill, as is used, for example, e.g. from Duda, ZEMENT-DATA-BOOK, volume 1, 3rd edition, 1985, about pp. 255 to 259 is known. Such an embodiment is illustrated with reference to FIG. 2.

Accordingly, the material bed shredding machine 31 in the form of a material bed roller mill according to FIG. 2 contains, as essential parts, two rollers 33, 34 which are pressed against one another under high pressure and can be driven in opposite directions (arrows 32) and form a grinding gap 35 between them and in a machine housing 36 are arranged. In the area immediately below the grinding gap 35, the deagglomeration zone 37 is again formed, in which agglomerates of the comminution product formed during the comminution of the material bed are to be dissolved as far as possible.

According to the same principle as in the first exemplary embodiment, there is also a liquid supply device in this deagglomeration zone in this case (FIG. 2) 37, that is to say inside the material bed comminution machine 31 and immediately behind the grinding gap 35 — viewed in the direction of material flow (arrow 10). Here, too, the liquid injection device is again primarily formed by a plurality of liquid supply pipes 11 ', which open into the deagglomeration zone 37 for supplying the pressurized liquid, in particular water (essentially the same as in the example in FIG. 1).

In addition, a mechanical deagglomeration device 38 is expediently also arranged in this deagglomeration zone 37, which contains at least one rotatingly drivable dissolving member, which is preferably formed in the form of a racket member or - as indicated in FIG. 2 - by at least one paddle screw 39, which at the same time has a conveying effect for has the dissolved material out of the machine housing 36 into the directly downstream wet classifier 6 '. This wet classifier 6 ', which is constructed in principle in the same way as in the example in FIG. 1, is constructed in the illustration according to FIG. 2 approximately next to the material bed comminution machine 31 and forms a structural unit with the latter. In the same way as in the first example (FIG. 1), this wet classifier 6 'in turn contains a liquid trough 19', a fine material outlet 21 ', an inclined feed screw 22' and a coarse material outlet 23 'which is connected to the inlet 31a via a recirculation conveyor 25' the material bed shredding machine 31 is connected.

In the investigations on which the invention is based, it was found that with both the embodiments described above and illustrated in the drawing the comminution device a very reliable and possibly also extremely gentle deagglomeration of the comminution product coming from the material bed comminution can be achieved, with the latter also contributing above all to a very dosed and pressure-controllable addition of liquid, which at the same time ensures that the material bed comminution machine is kept clean, especially in the area of the deagglomeration zone. The liquid consumption can be kept relatively low, especially since this supplied liquid can still be used in the downstream wet classifier. In the case of the material bed comminution machine 1 according to the example in FIG. 1, energy-efficient material bed comminution and particularly good handling of earth-moist mineral goods can be achieved.

Claims (15)

Process for the comminution of moist mineral material in the comminution zone of a product bed comminution machine with subsequent dissolution of agglomerates formed in the product bed comminution, this deagglomeration being followed by wet classification of the product,
characterized,
that the comminution product is exposed to a liquid injection with at least partial disagglomeration effect within the material bed comminution machine and immediately after leaving the comminution zone, and this supplied liquid is then fed to the wet classification together with the comminution product. A method according to claim 1, characterized in that the comminution product leaving the comminution zone is additionally subjected to a mechanical deagglomeration in addition to the liquid injection. A method according to claim 1, characterized in that the liquid is injected with the presetting of a minimum pressure, possibly a liquid high pressure. Method according to Claim 1, characterized in that the liquid is injected into the region immediately downstream of the comminution zone in such a way that the material bed comminution machine is in this interior region Existing inner walls and machine parts are flushed away from good particles. A method according to claim 1, characterized in that the comminution product is separated during the wet classification into a fine material to be removed and into a coarse material to be re-fed to the material bed comminution machine. Containing device for crushing moist mineral material a) a material bed comminution machine (1, 31) with a comminution zone which is formed by a grinding gap (7, 35) between two grinding surfaces (8, 9, 33, 34) pressed against one another at high pressure, b) a deagglomeration device (5, 38) for dissolving agglomerates formed in the material bed comminution, c) a wet classifier (6, 6 ') connected to the deagglomeration device, characterized in that d) a disagglomeration zone (17, 37) is formed within the material bed comminuting machine (1, 31) and - viewed in the material flow direction (10) - immediately behind the grinding gap (7, 35), in which a at least partial deagglomeration of the comminution product is effected Liquid injection device (11, 11 ') is provided and the wet classifier (6, 6') is arranged directly after it. Apparatus according to claim 6, characterized in that the liquid injection device contains a number of liquid supply pipes (11, 11 ') distributed in the deagglomeration zone (17, 37), which are connected to a control device (12) for adjusting the liquid pressure . Apparatus according to claim 6, characterized in that the wet classifier (6, 6 ') is arranged directly below or next to the material bed shredding machine (1, 31) and / or forms a structural unit with the latter. Apparatus according to claim 8, characterized in that the wet classifier (6, 6 ') with a liquid trough (19, 19'), a fine material outlet (21, 21 ') arranged in the region of the liquid level (20), and a conveying member arranged in the liquid trough ( 22) and a coarse material outlet (23, 23 ') provided at one end of this conveying member, the coarse material outlet being connected via a recirculation conveyor (25) to the inlet (1a, 31a) of the material bed comminution machine (1, 31) . Apparatus according to claim 9, characterized in that the wet classifier (6, 6 ') is designed in the form of a screw classifier, the conveying member (22) of which is a screw conveyor conveying obliquely upwards to the coarse material outlet (23, 23'). Apparatus according to claim 6, characterized by a material bed comminution machine (1) with a fixed first grinding track (8) arranged essentially horizontally aligned in a machine housing (4), a second grinding track (9) which can wobble relative to the first grinding track, a driven swash plate (14) for generating a wobbling movement of the second grinding path, through which the width of the grinding gap (7) formed between the two grinding paths increases and decreases periodically, the two grinding paths (8, 9) being designed as essentially flat ring paths and around a flat one Are inclined at an angle to one another, the swash plate (14) carries a cover (15) that runs around it, through which the grinding gap is covered to the outside in a peripheral partial zone that covers the gap area, and the ground material (2, 3) to be comminuted further Grinding gap (7) fed from the radially inner circumference and practice the comminution product (16) r the outer circumference of the grinding gap is discharged and the deagglomeration zone (17) is formed in an annular space approximately in the area between the grinding tracks (8, 9) and the inner circumferential side (4a) of the machine housing (4). Apparatus according to claim 11, characterized in that in addition to the liquid injection device (11), a mechanical deagglomeration device (18) is arranged in this annular space, which is provided in the discharge area of the grinding gap (7) and is at least partially rotationally fixed with the swash plate (14) connected, approximately strip-shaped or racket-shaped deagglomerating elements (18). Apparatus according to claim 6, characterized in that the comminuting machine (31) is designed in the form of a material bed roller mill in which two rollers (33, 34) which are pressed against one another under high pressure and can be driven in opposite directions form the grinding gap (35), and that the deagglomeration zone (37) is formed in the area immediately below the grinding gap. Apparatus according to claim 13, characterized in that in the deagglomeration zone (37) a plurality of liquid injection pipes (11 ') for the supply of liquid under pressure open out and in that a mechanical deagglomeration device (38) is additionally arranged there. Device according to claim 14, characterized in that the mechanical deagglomeration device (38) contains at least one rotatingly drivable dissolving member, preferably a racket member or a paddle screw (39) with a conveying effect.

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