EP0879086B1 - Roller mill - Google Patents

Abstract

The invention concerns a roller mill, in particular an air-swept mill of modular construction, with a rotating grinder vessel in which grinding rolls roll off, and with stands on which the grinding rolls are mounted via rocking levers, each of the stands being secured to a frame and arranged so as to form a mill frame. According to the invention, in order to use stable and torsion-resistant stands for relatively large roller mills, the stand frame and connecting frame parts are arranged in a mill bed so as to form a peripheral frame, in particular a polygonal or U-shaped frame. A gear frame is disposed in the mill centre, separately from the peripheral frame, and enables respective regions of the mill frame to be formed at different levels.

Description

The invention relates to a roller mill, in particular a Airflow mill in modular design, according to the preamble of Claim 1.

Modular roller mills are relatively large mills with two, three, four or more on a rotating grinding bowl rolling grinding rollers. With these according to a modular system developed roller mills is a building block Force unit used, consisting of a stand with rocker arm bearings, Rocker arm, complete grinding roller, rocker arm seal compared to a mill housing and a loading unit from a suspension cylinder with hydraulic accumulators exists and a relatively small grinding bowl twice, a middle grinding bowl triple and one large grinding bowl can be assigned four or more times can. The modular design enables without a special one constructive effort an adaptation to the respective need.

1 shows a known roller mill in sections shown in a side view and without housing. Grinding rollers 7, each with a rocker arm 8 pivotable about a rocker arm axis 28 of a stand 2 are stored, roll on a through a drive shaft 27 grinding bowl 3 driven by a gear 4.

It is a roller mill with two or more grinding rollers, of which only one grinding roller 7 is visible. Shown is also a rocker arm unit from one Rocker arm cylinder 6 and a hydraulic accumulator or one Gas spring 16. The stand 2, each of which is a grinding roller 7 are assigned, are at their lower end in an area a mill foundation 13, which is usually a Concrete foundation is on a steel foundation frame 5 attached, e.g. screwed and / or welded.

The known roller mills each have a foundation frame 5 per stand 2, which to one of a longitudinal axis 14 of the mill defined by the mill center is. In a roller mill with two grinding rollers 7 results yourself by extending the foundation frame 5 of the two diametrically arranged uprights 2 one from the foundation frame 5 of a stand 2 with a gear foundation frame 11 connected in the mill center and to the foundation frame 5 of the other stand 2 continuous mill foundation frame 18, usually the mill gear 4 over an intermediate plate or a gear base plate 12 with the Gear foundation frame 11 and the continuous mill foundation frame 18 is anchored.

For a roller mill with three grinding rollers and with more than four grinding rollers result in a star-shaped mill foundation frame 18. Such a star-shaped mill foundation frame 18 is a schematic diagram in FIG. 3 shown. This Figure 3 is in connection with the invention Solution described below.

A roller mill with four grinding rollers 7 results in a cruciform mill foundation frame 18, which also as a special form of a star-shaped mill foundation frame can be viewed.

Although roller mills and in particular airflow roller mills are already characterized by high grinding capacities, there are limits to further enlargement according to the "cranesbill principle". This is due to the fact that, in the case of roller mills of larger diameter and when using more than two grinding rollers with the required production output, for example the drive power also has to be increased and the grinding bowl must also be increased in height in addition to its diameter. It is necessary to use gear units with a larger overall height H _G2 (see Figure 2).

The overall height H _{M2 of} the grinding bowl 3 also increases because of the fluid space to be enlarged under the grinding bowl, since in the case of airflow roller mills, the volume flows also increase with increasing production output. The overall height H _{S1 of} the stand 2 thus increases by the amount H _ΔS and reaches a height of H _S2 according to FIG. 2. A comparison of FIGS. 1 and 2 with regard to the overall heights of the gears 4, the grinding bowls 3 and the stand 2 reveals that the increase in the height H _{ΔS of} the stator 2 according to FIG. 2 is due to the increase in the height of the gear 4 and the grinding bowls 3 of the larger roller mill of FIG. 2.

If stands of the same cross section were used as in the case of relatively small roller mills, for example roller mills with two grinding rollers, and a larger height required, the stability would be considerably impaired. A greater overall height H _{S2 of} the stand 2 has a disadvantageous effect on the strength of the stand 2 and the mill foundation frame 18 as a result of the bending moments and torsional moments introduced.

While in the previous mill designs the Bending moments initiated via a to the mill center extended foundation frame 18 are included had to up to the gear foundation frame 11 or Gear foot plate 12 of the gear 4 was sufficient, this is sufficient Construction the stability and strength requirements not with large mills, because depending on the Mill enlargement necessary stand extension too much high bending and torsional stresses on the stator connections leads to and in the foundation frame.

The disadvantages of these bending and torsional moments on the foundation side show with extended stands of large mills even with roller mills with a so-called "torsional stiffness Kranz ", which is described in DE PS 21 28 929 is. A torsionally rigid unit is only in the upper area the stand is formed so that the torsional and bending moments exclusively via the stand foundation frame in the foundation can be initiated. A clear one Magnification of the roller mill would therefore be known for this Roller mill construction to higher stands and to associated instabilities and impairment of operational security.

The invention has for its object to provide a roller mill, which when using the known and previously stand systems or modules with proven, in particular a constant level while safeguarding the necessary stability used an enlargement of the roller mill and, in particular, connected to the magnification of the bowl diameter extraordinary increase the grinding bowl and the gearbox and thus the grinding capacity.

According to the invention the task is characterized by Features of claim 1 solved. Advantageous and functional Refinements are in the subclaims and in included in the description of the figures.

The invention is based on the basic idea of a suitable one constructive design of the foundation-side frame construction the stand of a roller mill also for one necessary increase in height of gearbox and / or Grinding bowl to achieve sufficient stability.

According to the invention, a roller mill with two, three or more milling drum-stand modules a surrounding foundation frame on which all the foundation frames of the stands together connects. A particularly torsionally rigid foundation frame is determined by the respective foundation framework of each Stand and formed by connecting frame parts, the connecting frame parts each between two adjacent Foundation frame of the stand are provided.

A stable and extremely torsion-resistant construction stand and foundation frame is encircled by a closed and preferably by a polygonal arrangement the foundation frame of the stands and the connecting frame parts guaranteed. By the foundation or Base frame of each stand via a connecting frame part or a foundation frame connecting element to one encircling, closed bandage, or to a U-shaped or horseshoe-shaped bandage put together torsion and bending moments that are at the foot of a each stand is introduced into the foundation frame, supported individually or in cooperation.

A separate formation of the rotating one is particularly useful Stand foundation frame and a gearbox foundation frame. By such a separation of the rotating Foundation frame and the gearbox foundation frame in an extremely advantageous manner Possibility of leveling the surrounding foundation frame the stand against the level of the foundation frame of the Mill gear can be selected independently of one another and freely.

As a rule, the gear base frame is arranged in the mill center, ie in the area of the longitudinal axis of the mill. Depending on the overall height, which can be composed of the height H _{M2 of} the grinding bowl and H _{G2 of} the gear (Fig. 2), such a frame-side foundation arrangement is created that a stand of conventional height and required stability and torsional rigidity can be used.

For example, a polygon frame in the mill foundation the mill, which is the gear foundation frame in one surrounding defined distance in a different Height level to be arranged to the transmission base frame. With a mill enlargement with noticeable enlargement the height of the gear unit and the height of the grinding bowl, which leads to a corresponding enlargement of the stand could result in being extraordinarily efficient Measure a defined and limited increase in foundation, namely in the area of the gearbox foundation frame surrounding annular, polygonal or U-shaped foundation frame be carried out so that stands of normal height can be used.

Different level ranges of a mill foundation are known per se. So is in DE PS 153 958 Cone mill described with eight grinding cones, their bearing housing on an elevated, octagonal area of the mill foundation are arranged. In the elevated Mill foundations are also inserted nuts, which interact with an adjustment mechanism to a parallel position of the working surfaces of the grinding cone and the To be able to adjust grinding plates. The mill foundation of this well-known cone mill and the octagonal, elevated area do not have a foundation frame, which is for large mills would be required.

The known solution can only be used in small mills applied where there is no need to the roller units together via a connecting To support the foundation frame against each other.

Mushroom-shaped mill foundations with a raised area below the mill gear are known. The order a foundation frame and in particular a circumferential one The base frame of the stand is not described. As a rule, only the mushroom-shaped mill foundation a foundation frame in the area of the gearbox on, while the forces absorbed by the stands are direct and introduced into the mill foundation without a steel frame become.

The all-round foundation frame is in an appropriate training in a compared to the gearbox foundation frame or a gear footplate located higher concrete wall.

It may also be useful to use the gear foundation frame on an approximately mushroom-shaped foundation increase compared to the To arrange polygon frames of the stands with a lower level.

Significant advantages of the rotating according to the invention Foundation frame training are the possibility of separation this ring-shaped, polygonal or U-shaped stand foundation frame from a particularly centrally arranged Gearbox foundation frame and the bending and torsional stiffness Manufacture of a steel girder foundation frame for special large roller mills, so that their bending and torsional forces not just be introduced into reinforced concrete have to. In principle, instead of steel beams, too about reinforcement bars arranged in a ring or basket-like manner be used.

By the foundation frame according to the invention, the overall height of the Mill stand is limited to a minimum, which is ensured by the rocker arm and the associated hydropneumatic Suspension system is specified, there is a limitation the bending and torsional moments introduced into the mill stand. The result is improved stability and strength the stand and the roller mill. Additional advantages are a possible use of smaller machine tools for the mechanical processing due to the lower weight and the reduced overall height as well as a reduction in Manufacturing costs.

A major advantage is the possible compensation the heights of the gear and bowl compared to the height the stand over the foundation, for example over a Foundation increase or mushroom-shaped design given.

While with the previously known solutions for mills with common mill and gear frame due to the star or cruciform foundation frame with the same height and continuous horizontal course a foundation-side Height change was not possible, this succeeds with the invention circumferential foundation frame and one separately and centrally arranged gear base frame.

Fig. 1

eine Seitenansicht einer bekannten Wälzmühle, jedoch ohne Gehäuse;

Fig. 2

eine Wälzmühle in einer analogen Darstellung zur Fig. 1, jedoch mit einer größeren Bauhöhe der Ständer, der Mahlschüssel und des Getriebes;

Fig. 3

eine Prinzip-Darstellung eines sternförmigen Fundamentrahmens nach dem Stand der Technik;

Fig. 4

eine Prinzip-Darstellung der erfindungsgemäßen Fundamentrahmenausbildung;

Fig. 5 und 6

eine Draufsicht und schematische Darstellung eines Polygonrahmens mit drei Ständern bzw. vier Ständern;

Fig. 7

eine erfindungsgemäße Wälzmühle ohne Gehäuse und mit einem erhöhten Mühlenfundamentbereich für einen umlaufenden Fundamentrahmen;

Fig. 8

eine alternative Darstellung einer erfindungsgemäßen Wälzmühle mit einem pilzförmig ausgebildeten Getriebe-Fundamentrahmen und einem umlaufenden Fundamentrahmen und

Fig. 9

eine alternative Darstellung einer Ständer-Anordnung mit einem U-förmigen Fundamentrahmen in einem erhöhten, wallartigen Bereich eines Mühlenfundaments.

The invention is explained below with reference to a drawing; in this show in a highly schematic representation

Fig. 1

a side view of a known roller mill, but without a housing;

Fig. 2

a roller mill in an analog representation of Figure 1, but with a greater height of the stand, the grinding bowl and the gear.

Fig. 3

a schematic diagram of a star-shaped foundation frame according to the prior art;

Fig. 4

a schematic diagram of the foundation frame training according to the invention;

5 and 6

a plan view and schematic representation of a polygon frame with three stands or four stands;

Fig. 7

a roller mill according to the invention without a housing and with an elevated mill foundation area for a circumferential foundation frame;

Fig. 8

an alternative representation of a roller mill according to the invention with a mushroom-shaped gear foundation frame and a circumferential foundation frame and

Fig. 9

an alternative representation of a stand arrangement with a U-shaped foundation frame in an elevated, wall-like area of a mill foundation.

In Fig. 1 is a known roller mill in a side view with two grinding rollers, of which only one Grinding roller 7 and a stand 2 with rocker arm axis 28 and rocker arm 8 and with a hydropneumatic suspension 6, 16 is shown. At its lower end is the Stand 2 on a foundation frame 5 of a mill foundation 13 attached. The foundation frame 5 is up to Mill center, i.e. up to a gear foundation frame 11 extends and forms with the not shown, diametrically arranged foundation frame 5 of the second grinding roller-stand unit a continuous mill foundation frame 18 with a uniform height level.

2 shows a roller mill with four grinding rollers, of which only two grinding rollers 7, but only one stand 2 with grinding roller 7 are visible. Identical features are provided with identical reference symbols. The four-roll mill according to FIG. 2 illustrates the need for an extension of the stand by the difference H _ΔS so that the stand 2 reaches the required height H _S2 . The necessity is due to a larger overall height H _{M2 of} the grinding bowl 3 and a greater overall height H _{G2 of} the gear 4 compared to FIG.

With an extension of a shown in Fig. 2 Stand 2 are connected to instabilities, so that operational safety can be at risk.

The underlying means-effect relationship is intended to be shown in FIGS. 3 and 4 the invention will be clarified. 3, which, as from the stand 2nd shows that it should be a three-roll mill has one hitherto usual star-shaped mill foundation frame 18, that of the base frame 5 of the stand 2 and a gear base frame 11 of a transmission, not shown is formed. The stand 2 have according to the known and described in connection with Fig. 2 constructive Solution concept a larger height and one resulting in lower torsional rigidity and stability than the stand 2 of a trained according to the invention Rolling mill according to FIG. 4.

To prevent instabilities and milling drum stand modules with especially well-known and proven dimensions to be able to use even the highest performance roller mills, a circumferential foundation frame 9 is provided according to the invention, of a centrally located gear foundation frame 11 surrounds at a distance and separated in terms of frame. Fig. 4 shows the separation of the transmission base frame according to the invention 11 and the circumferential foundation frame 9, which represents a stable stand-base frame composite. The transmission foundation frame 11 and the rotating one Foundation frames 9 can be used independently of one another in mill foundation areas arranged with different heights be so that the use of the stand known and tried Height is possible.

Fig. 5 shows in a plan view as a built-in revolving Foundation frame 9 a polygon frame 10 one Rolling mill with three grinding rollers. The polygon frame 10 has three corner areas 22 in which the foundation frame 5 is arranged are. On the foundation frame 5 are stands (not shown) attached via their stand feet 20, for example screwed. To form a torsionally rigid polygon frame 10 are between the individual foundation frames 5, which can be rectangular, for example, Connection frame parts 17 arranged.

In a central arrangement is a gear base frame 11 provided, which on the foundation frame side with the Polygon frame 10 is not connected. So that's it Possibility to create the polygon frame 10 and Gear foundation frame 11 according to requirements with a different height level in a mill foundation 13 (see Fig. 7 or 8).

6 is a four-roll mill as a further embodiment shown. In four corner areas 22 are again arranged approximately rectangular-shaped foundation frame 5, the connecting frame parts 17 to a polygon frame 10 are connected. The connecting frame parts 17 can laid almost parallel in a foundation area 13, 15 Steel beams 19, in particular double-T beams, exist.

7 and 8 show an example and in a partial representation Rolling mills with a polygon frame 10 made of foundation frames 5 of the stand 2 and connecting frame parts 17 (not visible) whose height level is different from the height level of a centrally arranged gear base frame 11 differs.

In Fig. 7, the polygon frame 10 is formed as a wall Foundation increase 15 arranged. The transmission foundation frame 11 is much lower in a corresponding trained area 25 of the mill foundation 13. To increase the performance of the roller mill, a larger and higher roller bowl 3 and / or a larger one and higher gear 4 are used, advantageously Stand 2 known and tried size used can be.

Fig. 8 shows a mushroom-like mill foundation 13 with a elevated level in area 15 of a transmission foundation frame 11. The same components are again with identical reference numerals Mistake. With stands of the same size 2 can a smaller roller mill can be built modularly, at which the roller bowl 3 and the gear 4 a smaller Have height and therefore an elevated area 15 of Mill foundation 13 in the area of the gear foundation frame 11 is provided.

A development of a circumferential foundation frame 9 is shown in a perspective view in FIG. 9. A large mill with four grinding rollers (not shown) has as a circumferential foundation frame 9 a U-shaped or horseshoe-shaped frame 21. This U-shaped frame is in a foundation wall as an elevated area 15 of the mill foundation 13 added and includes two as Corner areas 22 of the foundation frame 5 of the stand 2 and two foundation frames 5 arranged as end regions 24 the stand 2. The U-shaped or horseshoe-shaped formation of the wall-like, raised area 15 of the mill foundation 13 results from an assembly notch 26, which serves to assemble the mill gear. The assembly slot 26 forms an interruption of the otherwise closed polygon frame 10. The assembly notch is on the foundation frame side 26 of two foundation frames arranged as end regions 24 5 of the stand 2 limited.

In principle, also with a U-shaped foundation frame 21 achieved high stability, which is why not in everyone Case a closed, all-round foundation frame is made must become.

A possible weakening of the torsionally rigid can advantageously Foundation frame association by one or more Support traverses 29 are compensated. These support beams 29, which is particularly analogous to the steel beams of the Connecting frame parts 17 are formed and with the Steel beams 23 of the base frame 5 of the stand 2 releasable and thus can be connected in a demountable manner after a Installation of the gearbox, for example above or below a pipe extension of the drive coupling between the mill motor and the mill gear (not shown) be arranged. By the support crossbars 29 as a removable Connecting frame part can be used U-shaped or horseshoe-shaped foundation frame 21 again to a closed, all-round and polygonal foundation frame association be formed.

An extremely stable and torsionally rigid construction is achieved if in addition to the surrounding foundation frame 9, which has a foundation-side torsional stiffness Association forms, in the upper area of the stand 2 torsionally rigid ring is formed according to DE PS 21 28 929. In Fig. 9 are between the stands 2 in the upper area and at the height of the pedestals or the rocker arm axles 28 Connection elements 30 shown, which with the stand areas form a so-called "torsionally rigid ring". By doing both by a mill foundation frame 9 and on upper end of the stand 2 formed a stable association is high stability and operational security trained large mills guaranteed.

Basically, it is possible to replace the steel girder the surrounding foundation frame 9 and the central trained gear foundation frame 14 armored accordingly or to provide reinforced concrete areas with steel bars. For example, a reinforced concrete area can be basket-like have arranged steel bars.

Claims (15)

1. Roller mill, particularly an air-swept mill in modular construction, having a rotary grinding pan (3) on which roll grinding rollers (7), and having columns (2) on which are mounted the grinding rollers (7) and which are fixed to foundation frames (5) of a mill foundation (13),
   characterized in that

   between the foundation frames (5) of the columns (2) are provided connecting frame parts (17), which in each case connect two adjacent foundation frames (5) of the columns (2) together to a circumferential foundation frame (9).
2. Roller mill according to claim 1,
   characterized in that

   the foundation frames (5) of the columns (2) and the connecting frame parts (17) form a polygonal frame (10) as a circumferential foundation frame (9), and

   that the foundation frames (5) of the columns (2) are arranged as corner areas (22) of the polygonal frame (10).
3. Roller mill according to claim 1 or 2,
   characterized in that

   the circumferential foundation frame (9) is arranged in spaced manner with respect to a gear foundation frame (11),

   the gear foundation frame (11) is positioned in the mill centre (14) and is surrounded by the circumferential foundation frame (9), and that

   the gear foundation frame (11) and the circumferential foundation frame (9) are placed as separate foundation frames in the mill foundation (13).
4. Roller mill according to one of the preceding claims,
   characterized in that

   the circumferential foundation frame (9) and gear foundation frame (11) are positioned in different height areas (15, 25) of the mill foundation (13) and columns (2) of uniform overall height (H_S) are usable.
5. Roller mill according to claim 4,
   characterized in that

   the circumferential foundation frame (9) and the gear foundation frame (11) is in each case located at a level of the mill foundation (13) determined by the overall height (H_M) of the grinding pan (3), the overall height (H_G) of the gear (4) and the overall height (H_S) of the columns (2), which can be used for different sized grinding pans (3) and gears (4), representing the reference size.
6. Roller mill according to claim 4 or 5,
   characterized in that

   compared with the gear foundation frame (11), the circumferential foundation frame (9) is located in a higher area (15) of the mill foundation (13).
7. Roller mill according to claim 6,
   characterized in that

   the circumferential foundation frame (9) is positioned in a higher area (15) of the mill foundation (13) constructed as a rampart.
8. Roller mill according to one of the preceding claims 4 to 7,
   characterized in that

   the circumferential foundation frame (9) is constructed in a higher, rampart-like area (15) of the mill foundation (13) with an assembly gap (26) as a U-shaped or horseshoe-shaped frame (21), which has connecting frame parts (17) and corner areas (22) and end areas (24), which are formed by the foundation frames (5) of the columns (2).
9. Roller mill according to claim 8,
   characterized in that

   the foundation frames (5) of the columns (2) arranged as end areas (24) and which bound the assembly gap (26), are detachably connected by supporting cross-beams (29) in the operating state of the roller mill.
10. Roller mill according to claim 5 or 6,
    characterized in that

    compared with the gear foundation frame (11), the circumferential foundation frame (9) is located in a lower area (25) of the mill foundation (13).
11. Roller mill according to claim 10,
    characterized in that

    the mill foundation (13), in which are separately received the circumferential foundation frame (9) and the central gear foundation frame (11), has a mushroom-shaped construction in the area of the gear foundation frame (11).
12. Roller mill according to one of the preceding claims,
    characterized in that

    the foundation frames (5) of the columns (2) arranged as corner areas (22) and end areas (24) in the circumferential foundation frame (9) have a rectangular construction in plan view and consist of steel girders (23), particularly double T-girders.
13. Roller mill according to one of the preceding claims,
    characterized in that

    the connecting frame parts (17) comprise virtually parallel arranged steel girders (19), particularly double T-girders, which are connected with the steel girders (23) of the foundation frames (5) of the columns (2).
14. Roller mill according to one of the claims 1 to 11,
    characterized in that

    the circumferential foundation frame (9) and/or the gear foundation frame (11) is in particularly constructed from annular reinforced concrete.
15. Roller mill according to one of the preceding claims,
    characterized in that

    in addition to the circumferential foundation frame (9) a torsionally stiff construction of connecting elements (30) is formed, and that

    the connecting elements (30) are positioned between the columns (2), particularly in an upper area close to the rocker axis (28).

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