EP0562289A2 - Roller mill - Google Patents

Abstract

The invention relates to a roller mill with a rotatably driven milling plate which has a horizontal milling path, with at least one pair of milling rollers and at least one roller carrier whose ends are guided via guide shoulders in housing guides and are coupled to traction rods. In order to achieve particularly quiet running of the milling rollers on the milling path, at least the housing guides and the guide shoulders, guided therein, of the external roller carrier ends are located approximately at the level of the horizontal plane of the milling path. <IMAGE>

Description

The invention relates to a roller mill according to the preamble of claim 1.

Rolling mills, in particular so-called spring roller mills, of the type required in the preamble of claim 1 are sufficiently known from practice. These roller mills are used for crushing different granular or lumpy goods, such as. B. cement materials, ores, coal or the like. One embodiment of this roller mill is known for example from DE-B-12 50 724. The two rollers of a pair of rollers are each freely rotatably supported on one side of a roller carrier, whereby they are mutually supported on a roller axis when they are mounted on the fly. The two ends of each roller carrier protrude outwards beyond the circumference of the grinding table and are guided vertically approximately at the level of the grinding roller axis via outer guide pins or bolts in housing guides, pivot points for the upper ends of the tie rods being formed via these guides. An advantage of these known roller mills with pairs of grinding rollers is seen in the fact that each grinding roller of a pair can adapt in terms of its peripheral speed to that of the associated (outer or inner) grinding track region, as a result of which the wear on the circumference of the grinding rollers can be kept relatively low.

In the practical comminution operation of these known roller mill designs, the grinding material movement and the centrifugal forces caused thereby create radial forces on the grinding track, which try to use the friction that occurs, the grinding rollers around the guide pins to tilt the roller carrier, ie tilting moments acting on the associated grinding roller pair are generated around the vertical sliding guides of each roller carrier. With this friction, which arises in particular between the material to be ground and the grinding rollers, their coefficient of friction changes in accordance with the different material conditions (grain sizes, material moisture, material bed density, material bed thickness, etc.), which means that different tilting moments can constantly occur, which lead to an additional constant movement in the material bed and thus disrupt the shredding operation .

The invention is therefore based on the object of improving a roller mill of the type required in the preamble of claim 1 in such a way that undesirable torques or tilting moments in the region of each grinding roller pair and each associated roller carrier can be reliably avoided with a relatively simple construction and a particularly quiet one Run of the roller mill is guaranteed.

This object is achieved by the features specified in the characterizing part of claim 1.

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

In this roller mill according to the invention, at least the housing guides and the guide lugs guided therein lie at the ends of each roller carrier approximately at the height of the horizontal grinding track plane. In addition, it is considered to be particularly advantageous if the articulation points of the upper tie rod ends on the outer roller carrier ends are also approximately at the height of the horizontal Grinding path level and next to the guide approaches or if these articulation points are sensibly below the horizontal grinding path level.

As the studies on which the invention is based have confirmed, an indifferent equilibrium can be achieved on each roller carrier with an associated pair of grinding rollers by the above-mentioned laying of at least the above-mentioned guides for the roller carrier ends approximately at the level of the horizontal grinding path plane. As a result, in the area of the guide lugs of each roller carrier, disruptive torques or tilting moments which arise from the radial forces of the grinding process in the grinding path plane of the known mill designs are reliably and easily avoided. This indifferent equilibrium can be achieved according to the invention by arranging the guides mentioned, for example in the grinding path plane, and also by arranging the articulation points of the upper tie rod ends on the outer roller carrier ends in this grinding path plane.

If, on the other hand, only the housing guides and the guide lugs of each roller carrier are located approximately at the level of the grinding path level, while the articulation points of the upper tie rod ends on the outer roller carrier ends are provided below the horizontal grinding path level and below the corresponding guide extensions, then a stable balance is created for each roller carrier together with a pair of grinding rollers around its leadership approaches.

Both in one embodiment (indifferent balance) and in the other embodiment (stable balance), disruptive rotation or Tipping moments on the roller carrier and thus on the associated pair of grinding rollers can be avoided, so that particularly smooth running of the grinding rollers or the entire roller mill can be ensured.

Since, in this embodiment according to the invention, the grinding roller pairs can roll relatively quietly on the grinding track or the grinding material bed located thereon, any radial oscillating movements between grinding rollers and grinding material are reduced to a minimum, thereby stabilizing the grinding material build-up and thus increasing the effectiveness of the grinding work can. This extremely favorable grinding work also leads - as tests have confirmed - to energy savings for the operation of this roller mill according to the invention.

Fig.1

eine teilweise Vertikalschnittansicht einer Hälfte der erfindungsgemäßen Wälzmühle;

Fig.2

eine Teil-Horizontalschnittansicht, etwa entlang der Linie II-II in Fig.1;

Fig.3

eine ähnliche Teil-Vertikalschnittansicht wie in Fig.1, jedoch von einer zweiten Ausführungsform der Wälzmühle;

Fig.4

eine Teil-Horizontalschnittansicht entsprechend der Linie IV-IV in Fig.3.

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

Fig. 1

a partial vertical sectional view of one half of the roller mill according to the invention;

Fig. 2

a partial horizontal sectional view, approximately along the line II-II in Figure 1;

Fig. 3

a similar partial vertical sectional view as in Figure 1, but of a second embodiment of the roller mill;

Fig. 4

a partial horizontal sectional view along the line IV-IV in Figure 3.

A first exemplary embodiment of this roller mill according to the invention will first be described with reference to FIGS. 1 and 2. Before going into more detail on the individual parts of this roller mill, it should be emphasized that only the parts required to explain the essential features of the invention are illustrated in FIGS. 1 and 2, i. H. In FIG. 1, only a rough - the left - half is illustrated in a highly simplified, schematic vertical section, while only about a quarter is shown in the horizontal sectional view of FIG. 2, since the other halves or quarters are approximately mirror images of those illustrated Partial cuts can be made.

• ein üblicher, um die vertikale Mühlenachse 1 - beispielsweise in Richtung des Pfeiles 3 - drehbar angetriebener Mahlteller 4, der an seiner Oberseite eine kreisringförmig ausgebildete, im wesentlichen horizontal ausgerichtete Mahlbahn 5 aufweist,
• wenigstens ein auf der Mahlbahn 5 abrollendes Mahlrollenpaar 6, vorzugsweise wenigstens zwei solcher gleichmäßig über die Fläche der Mahlbahn 5 verteilter Mahlrollenpaare 6,
• für jedes Mahlrollenpaar 6 ein sich oberhalb der Mahlbahn 5 und quer dazu erstreckender Rollenträger 7, an dem ein Mahlrollenpaar 6 um eine etwa horizontale Rollenachse 8 freidrehbeweglich und im wesentlichen ortsfest gehaltert ist und der an seinen beiden über den Mahltellerumfang bzw. -umfangsrand 4a hinausragenden äußeren Enden 7a - später noch näher erläuterte - Führungsansätze aufweist, die in Gehäuseführungen 9 vertikal und radial geführt sind, wobei auch eine gewisse Kippbeweglichkeit um die etwa horizontale Längsmittelachse 7b des Rollenträgers 7 möglich sein soll,
• sowie mehrere über den Umfang des Mühlengehäuses 2 verteilte, mit geeigneten Zugfedereinrichtungen (vorzugsweise hydraulischen Zugzylindern) 10 versehene Zugstangen 11, deren untere Enden 11a ortsfest, beispielsweise am Mühlenfundament 12 und deren oberen Enden 11b jeweils an einem entsprechenden äußeren Rollenträgerende, z. B. 7a, angelenkt sind.

The roller mill according to FIGS. 1 and 2 can generally be designed in the manner of a spring roller mill with a vertical mill axis 1. This roller mill can contain a conventional frame-like mill housing 2. This roller mill also includes

• a conventional grinding table 4, which is rotatably driven about the vertical mill axis 1 - for example in the direction of the arrow 3, and which has on its upper side an annular, essentially horizontally oriented grinding track 5,
• at least one grinding roller pair 6 rolling on the grinding track 5, preferably at least two such grinding roller pairs 6 evenly distributed over the surface of the grinding track 5,
• for each pair of grinding rollers 6, a roller carrier 7 extending above the grinding path 5 and transversely thereto, on which a pair of grinding rollers 6 is approximately horizontal Roller axis 8 is freely rotatable and essentially stationary and has at its two outer ends 7a protruding beyond the grinding plate circumference or circumferential edge 4a - which will be explained in more detail later - in guide guides which are guided vertically and radially in housing guides 9, with a certain tilting mobility about the approximately horizontal longitudinal central axis 7b of the roller carrier 7,
• as well as several distributed over the circumference of the mill housing 2, provided with suitable tension spring devices (preferably hydraulic tension cylinders) 10 tie rods 11, the lower ends 11a of which are stationary, for example on the mill foundation 12 and the upper ends 11b of which are each on a corresponding outer end of the roller carrier, e.g. B. 7a are articulated.

As can be seen in the drawing, each articulation point between an upper tie rod end 11b and an outer roller support end 7a can be formed on the one hand by an articulated hook 13 attached to the roller support end 7a and on the other hand by a shackle 14 articulated on the upper tie rod end 11b, this shackle 14 is suspended from the outside and above in the associated link hook 13.

In this first exemplary embodiment according to FIGS. 1 and 2, the above-mentioned guide lugs on each outer roller carrier end 7a are each caused by the vertically oriented and - with respect to the roller carrier 7 - axially outwardly facing outer surface 13a of the corresponding articulation hook 13 and by the two vertical ones outer side surfaces 7a 'and 7a''of this roller support end 7a. Matching these guide approaches, each housing guide 9 has - as can best be seen from FIG. 2 - three approximately perpendicular, vertically aligned guide surfaces 9a, 9b and 9c such that in the horizontal section the shape of a U open towards the grinding table 4 is formed is. This results in a reliable vertical and radial or axial guidance for the roller carriers 7 or the grinding roller pairs 6 carried by them with respect to the grinding track 5.

It is of particular importance in this roller mill that at least the housing guides 9 and the guide projections (13a, 7a ', 7a' ') on the outer roller carrier ends 7a are approximately at the level of the horizontal grinding track level 15 (this horizontal grinding track level 15 being included) perfectly flat grinding tracks 5 by their top or in the case of annular trough-shaped grinding tracks 5 - as illustrated - by an averaged horizontal plane). It should of course be taken into account that during grinding or comminution work, i.e. H. during the action of the grinding rollers 6 on a material bed located on the grinding track 5, the guide lugs 13a, 7a ', 7a' 'undergo certain vertical up and down movements within the housing guides 9 without these guide lugs, however, being clearly different from the horizontal in their general height Grinding path level 15 can get out.

In this first exemplary embodiment (FIGS. 1 and 2) it is further provided that the articulation points, which result from the interaction of the articulation hooks 13 and the shackles 14, also approximately at the height of the horizontal Grinding track level 15 and, in addition to the guide lugs mentioned, lie on the outer roller carrier ends 7a. Thus, the guidance of the outer tie rod ends 7a and the articulation points of the upper tie rod ends 11b on the outer roller carrier ends 7a are placed approximately in the horizontal grinding path plane 15, which creates an indifferent balance for roller carriers 7 and pairs of grinding rollers 6.

As can also be seen in FIG. 2, the two grinding rollers 6 of a pair of grinding rollers are arranged symmetrically on both longitudinal sides of the associated roller carrier 7 or on both sides of its horizontal longitudinal central axis 7b. At each outer roller support end 7a there is an axially outwardly directed end surface 7d, on each of which a pivot hook 13 provided with an outer vertical guide surface 13a is attached symmetrically on both sides of the horizontal longitudinal axis 7b of the roller support. Of these two articulation hooks 13 - in the illustrated example - one is used to hang the shackle 14, while of the second articulation hook 13 only its outer vertical guide surface 13a for the vertical guidance is slidably guided and supported on the guide surface 9b of the housing guide 9 facing it (for a corresponding guidance of the roller carrier end 7a). This design and arrangement of two link hooks 13 on each outer roller support end 7a offers the advantage that the associated upper tie rod end 11b - with the help of the shackle 14 - can each be hooked into that of the two link hooks 13, which guarantees the cheapest (most balanced) Provides tensile load for this roller support end. For fine correction of the different Roller wear between the inner and outer grinding rollers of each pair of grinding rollers 6 can also be displaced on the plate carrying the articulation hooks 13 on the end face 7d transversely to the roller carrier axis 7b (see FIG. 2) (for example by means of a corresponding screw connection).

The second exemplary embodiment of the roller mill illustrated in FIGS. 3 and 4 differs from the example described first (FIGS. 1 and 2) only with regard to the vertical guidance and the arrangement of the articulation points on the roller carrier ends. Since all other parts of the mill can be designed in the same way as in the first embodiment, the same reference numerals are used for these similar parts as in the first example, so that their detailed description can be omitted substantially and only some main parts are provided with the corresponding reference numerals.

In this second exemplary embodiment (FIGS. 3 and 4) of the vertical-axis roller mill, the guide lugs on the outer roller carrier ends 7a - in relation to the roller carrier 7 or its horizontal longitudinal central axis 7b - can be formed by cylindrical guide pins 20 projecting axially outwards from the roller carrier 7 be adapted, in turn, housing guides 9 are provided, each of which has three approximately perpendicular, vertically aligned guide surfaces 9a, 9b and 9c, which are arranged in horizontal section (FIG. 4) in the form of a U open towards the grinding table 4. The clear distance between the two opposite guide surfaces 9a and 9c (leg surfaces of the U) is the diameter of the associated one Guide pin 20 turned off, so that there is a reliable lateral, horizontal and radial or axial guidance for each roller carrier end 7a, the guide pin 20 on both roller carrier ends 7a of a roller carrier 7 expediently coaxially on the longitudinal central axis 7b of the roller carrier 7, so that thereby a certain pivoting mobility of the roller carrier 7 around its longitudinal central axis 7b is made possible, which is advantageous for the alignment of the grinding rollers 6 in the grinding path 5 (in adaptation to the respective material bed).

In the case of this second exemplary embodiment, only the housing guides 9 and the guide pins 20 of the roller carrier ends 7a forming the guide lugs lie approximately at the height of the horizontal grinding path plane 15.

In contrast, in this case (FIGS. 3 and 4), the articulation points of the upper tie rod ends 11b are provided on the outer roller carrier ends 7a below the horizontal grinding track plane 15 and with a real short, practical distance below the corresponding guide pins 20. In the same way as in the first exemplary embodiment, these articulation points can again be formed by shackles 14 articulated on the upper tie rod ends 11b and articulation hooks 13 projecting outward from the roller carrier ends 7a.

The fact that in this second exemplary embodiment the articulation points mentioned — unlike in the first example — are arranged below the grinding track plane 15, that is to say also below the guide lugs or guide pins 20, a stable equilibrium system results in this exemplary embodiment.

If one compares the two embodiments of the roller mill according to the invention explained with reference to FIGS. 1 to 4 with the known design described at the beginning (e.g. DE-B-12 50 724), then it can be seen that in this known design not only the guide bolts are relatively high above the grinding track level, but that the articulation points of the upper tie rod ends on the outer roller carrier ends are particularly high (still above the guide bolts mentioned). In the known roller mills, this can result in particularly large tilting movements of the pairs of rollers around the horizontal central longitudinal axes of the roller supports, inter alia, by the fact that different grinding bed thicknesses (for example due to fluctuating grinding material cycles) arise with the undesirably large frictional forces already mentioned at the beginning. Such constantly changing conditions of the regrind bed and the frictional forces or moments of friction result in undesirably large rocking movements (tilting movements around the longitudinal central axis of the roller carriers), which leads to an undesirably hard and uneven running of the mill (as the studies on which the invention is based have shown). between grinding rollers and grinding track). As a result of this interaction of the grinding rollers, the theoretical point of contact of the grinding rollers on the grinding track changes constantly, i.e. it moves inwards or outwards with each tilting movement of the roller carrier and thus of the pair of rollers, which always causes a deviation from the theoretically most favorable rolling radius. However, each of these deviations means braking or accelerating the respective grinding roller, which adds up to a particularly high energy consumption.

In contrast, in the inventive design and arrangement of the guides and articulation points of the roller carrier ends a deflection or excessive deflection of the roller carrier 7 and thus the grinding roller pairs 6 carried by them is reliably counteracted, so that - compared to the known design described - considerable energy savings in the grinding process can be achieved. By the said indifferent equilibrium system (example according to Fig. 1 and 2) and also by the stable equilibrium system (example according to Fig. 3 and 4), the radial oscillating movement between the grinding rollers and the material to be ground can be reduced to a minimum, thereby the structure of the regrind bed is stabilized and thus the grinding efficiency can be increased.

Claims (9)

Vertical-axis roller mill, containing a) a mill housing (2), b) a grinding table (4) rotatably driven about the vertical mill axis (1) with an essentially horizontal grinding track (5) formed on its upper side in a ring shape, c) at least one pair of grinding rollers (6) rolling on the grinding track (5), d) at least one roller support (7) extending above the grinding track (5) and transversely thereto, d1) on which a pair of grinding rollers (6) is rotatably supported about a roller axis (8) and d2) has at its two ends (7a) projecting beyond the grinding plate circumference (4a) guide lugs (7a ', 7a'', 13a, 20) which are guided vertically and radially in housing guides (9), e) a plurality of tie rods (11) distributed over the circumference of the mill housing (2) and provided with tension spring devices (10), the lower ends (11a) of which are fixed and the upper ends (11b) of which are articulated on an outer end of the roller carrier (7a), characterized in that f) at least the housing guides (9) and the guide projections (7a ', 7a'', 13a, 20) guided therein lie on the outer roller carrier ends (7a) approximately at the height of the horizontal grinding track plane (15). Rolling mill according to claim 1, characterized in that the articulation points (13/14) of the upper tie rod ends (11b) on the outer roller support ends (7a) also approximately at the height of the horizontal grinding track plane (15) and next to the guide lugs (7a ', 7a' ', 13a). Rolling mill according to claim 1, characterized in that the articulation points (13/14) of the upper tie rod ends (11b) are provided on the outer roller carrier ends (7a) below the horizontal grinding track plane (15) and below the corresponding guide lugs (20). Rolling mill according to claim 1, characterized in that the guide lugs on the roller carrier ends (7a) are formed by cylindrical guide pins projecting outward axially from the roller carrier (7). Rolling mill according to claim 1, characterized in that each articulation point between an upper tie rod end (11b) and an outer roller support end (7a) on the one hand by an axially outwardly projecting link hook (13) attached to the roller support end and on the other hand by an upper tie rod end (11b) arranged shackle (14) formed is, which is hooked into the articulation hook (13). Rolling mill according to claim 5, characterized in that the guide lugs on each outer roller carrier end (7a) are each formed by the vertical outer surface (13a) of an outer link hook (13) and the two vertical outer side surfaces (7a ', 7a' ') of this roller carrier end . Rolling mill according to claim 6, wherein the grinding rollers of a pair of grinding rollers are arranged symmetrically on both longitudinal sides of the associated roller carrier (7), characterized in that an axially outwardly facing end surface (7d) is formed on each outer roller carrier end (7a) and symmetrical on this end surface On both sides of the horizontal longitudinal central axis (7b) of the roller carrier (7) there is a link hook (13) provided with an outer guide surface (13a). Rolling mill according to claim 1, characterized in that each housing guide (9) for the guide lugs (7a ', 7a' ', 13a, 20) of the roller carrier (7) has three vertically aligned guide surfaces (9a, 9b, 9c) approximately at right angles to one another has that the shape of a U towards the grinding table (4) is formed in the horizontal section. Rolling mill according to claim 5, characterized in that the articulation hooks (13) are attached to the outer roller carrier ends (7a) so as to be adjustable in height.

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