EP0396897B1 - Crushing roll - Google Patents

Description

The invention relates to a grinding roller, in particular for use in a material bed roller mill, in which brittle ground material is comminuted between two grinding rollers pressed against one another at high pressure, according to the preamble of claim 1.

A grinding roller of the required type is described for example in an older, post-published proposal for a roller mill (DE-A-38 33 614). The main thing here is to clamp the individual jacket segments together with the aid of clamping plates which are provided on the end faces of the rolls and are clamped using clamping screws. In this roller mill proposed earlier, the wear of the segments that occurs when comminuting brittle regrind (for example cement clinker) and in particular the disturbing wear occurring in the area of the end faces of the segments and the repair work resulting therefrom are to be countered by the fact that the clamping plates completely cover the end faces of the segments cover and seal flush with the outer peripheral surface of the segments.

From DE-U-79 34 607, on the other hand, a grinding roller is known which, as can be seen from FIG. 3 there, is particularly suitable for use in vertical roller mills, spring roller mills or the like. The roller jacket provided there as a wear ring is produced in a similar manner to the previously explained embodiment from a multiplicity of jacket segments which are clamped together on the roller base body with the aid of front-side clamping plates, the special feature is that the segments are held on the base body in a dovetail guide. Nothing is said about the material used for the shell segments either in the roller mill according to DE-A-38 33 614 or in this DE-U-79 34 607.

EP-A-271 336 proposes a grinding roller which is produced essentially in one piece with its roller jacket which forms the comminution surface, in that this jacket is composed of alternately adjacent and preferably twist-extending first and second strip parts of different wear resistance. Both the first strip parts with higher wear resistance and the second strip parts with lower wear resistance can be attached in place on the roller base body, for example by welding, cladding, plating or casting, so that a one-piece unit consisting of roller base body and solid ( in one piece) roller roll attached thereon.

The invention is based on the object of developing a grinding roller of the type required in the preamble of claim 1 in such a way that it maintains the interchangeability of its shell segments with a relatively simple construction for particularly good intake behavior of the ground material to be comminuted in a roller mill, in particular in a material bed roller mill, contributes.

This object is achieved by the features specified in the characterizing part of claim 1, advantageous embodiments of this invention are described in the subclaims.

From GB-A-439 895 it is now already known, in the case of cylinders or rollers of comminution machines, in particular for grinding paint, chocolate or the like, the casing forming the grinding surface from a multiplicity of hard metal strips and strips arranged between two adjacent hard metal strips or put together layers of softer material, with all strips being approximately at right angles to the direction of rotation of the cylindrical rollers. In this case, a cylindrical base body is provided with a central circumferential dovetail projection, on which the hard metal plates provided with a corresponding dovetail recess are, as it were, pushed and strung together, a strip or a layer of the softer material then being provided as a separating strip or separating layer between these hard metal plates , furthermore, holes can be provided in this strip in order to pull wires or the like through there, and wherein retaining rings (with parts overlapping the strips) are screwed to the two ends for fastening the strips. The roll shell according to this known embodiment thus consists, with respect to the formation of the actual grinding surface, of an extremely large number of individual hard metal strips stacked together and soft material strips placed or attached between them, which are made of any materials, such as soft metal, paint, enamel, wood , Paper, leather, fabric or the like, can exist.

In the embodiment according to the invention of the grinding roller, in particular intended for the comminution of brittle regrind, on the other hand, in each segment of the roller shell which is largely made of hard cast material, several sheets of softer material are cast in, as mentioned in the characterizing part of claim 1. In this way, even after a very short milling operation, these sheets become slightly worn on the outer circumferential side of the roll shell, so that a resultant, to a certain extent profound outer shell surface is obtained. This proficient jacket surface contributes to a significantly improved drawing-in behavior for the regrind compared to the smooth-surface roller jackets mostly used in material bed roller mills.

In the case of grinding rollers, which are used above all for soft grinding, it is already known to roughen the surface of the casing or to profile it in a targeted manner by incorporating corrugations separately. This corrugation of the outer surface of grinding rollers must, however, be repeated from time to time in accordance with the wear of the outer surface that occurs, which entails corresponding assembly and reworking expenses as well as undesirable downtimes. In contrast, on a grinding roller according to the invention, even when the hard cast material from which the shell segments are predominantly made of wear, the cast-in sheets will always wear somewhat more in a corresponding ratio, so that the desired surface profiling of the roller shell is always obtained throughout the life of the roller segments remains what a unwanted reworking, as described above, is avoided.

By profiling the surface according to the invention However, the roll shell has yet another significant advantage in that the sheets cast into the segments prevent adjacent edges (profile edges) of the cast material from breaking out on the segments.

Fig. 1

einen Querschnitt durch eine erfindungsgemäß aufgebaute Mahlwalze;

Fig. 2

eine Perspektivansicht eines Walzengrundkörpers mit einem auf dessen Umfang angebrachten Segment;

Fig. 3 und 4

einen Teil-Längsschnitt bzw. einen Teil-Querschnitt von zwei weiteren Beispielen über die Anbringung und Befestigung von Segmenten auf dem Walzen gundkörper;

Fig. 5 bis 11

Teil-Aufsichten auf den abgewickelten Walzenmantel, zur Erläuterung verschiedener Ausführungsformen von in die einzelnen Segmente eingegossenen Blechen.

Some exemplary embodiments of the invention are explained in more detail below with reference to the drawing. Show in this drawing

Fig. 1

a cross section through a grinding roller constructed according to the invention;

Fig. 2

a perspective view of a roller body with a segment attached to its circumference;

3 and 4

a partial longitudinal section or a partial cross section of two further examples on the attachment and attachment of segments on the rolling base body;

5 to 11

Partial views of the unwound roll shell, to explain various embodiments of sheet metal cast into the individual segments.

In the cross section illustrated in FIG. 1 through the grinding roller 1 designed according to the invention, it can be seen that this grinding roller contains a roller base body 2 and a roller shell 3 which is arranged directly on the roller base body 2 and consists of individual - in the present example, six - annular segments 4 is composed. All six segments 4 are close to one another with the roller body 2 - preferably in the roller circumferential direction - Tense, as will be explained in more detail below. All segments 4 are formed uniformly and of equal size, so that they can be exchanged individually and with one another.

Each segment 4 is largely made of hard cast material, preferably hard cast (cast steel). In each segment 4 of the roll shell 3, a suitable number of sheets 5 arranged with circumferential spacings are cast in, which are made of a material softer than the chilled cast iron, preferably of essentially non-hardenable steel (structural steel). These sheets 5 run essentially transversely to the casing surface 3a and, viewed in cross-section according to FIG. 1, are oriented approximately radially to this casing surface 3a.

Preferably, all of the sheets 5 are in the form of essentially transverse, i.e. H. essentially running in the direction of the roll longitudinal axis, sheet metal strips, which are basically in any length (viewed in the direction of the axial roll length) and in any, most appropriate forms, d. H. Unprofiled or profiled in the longitudinal direction can be formed.

The radial height h of these sheets or sheet strips 5 can generally be of any type. This radial height of the sheet metal strips 5 cast into the segments 4 will preferably correspond approximately to a predetermined outer wear layer thickness of the roll shell 3, as is indicated in FIG. 1 for two segments 4 by a dash-dotted line 6.

FIG. 2 shows a perspective illustration of how each or each segment 4 of the roll shell 3 is fastened on the roll base body 2 can be. Then a correspondingly large number of sufficiently large, axially extending grooves 7 are provided on the outer circumferential side of the roller base body 2, and correspondingly profiled clamping plate segments 8 are arranged on the two opposite end faces 2a, 2b of the roller base body in such a way that they each have the appropriate profile Grip over the inner circumferential sides 4a of the associated jacket segment 4. Two clamping plate segments 8 acting on the two opposite end faces 2a, 2b of the roller base body 2 and of the respective segment 4 are then firmly clamped together with the aid of two axially extending clamping screws which are known per se and are therefore not illustrated in detail, so that they clamp the segments with the roller base body 2 tight.

Another embodiment of the attachment of the individual segments 4 on the outer circumferential side of the roller base body 2 is shown in FIG. 3. According to this, each segment 4 is formed with two front-side, axially opposing fastening flanges 4b and 4c, which fit on the outer circumferential side 2c of the roller base body 2 and with the aid of screw bolts 9 (left) or by means of one-piece clamping rings 11 (right half) on this outer circumferential side 2c of the roller base body 2.
FIG. 4 also shows a further possibility of how the roller base body 2 is, as it were, sawtooth-shaped in cross-section on its outer circumferential side, the correspondingly profiled inner side 4d of the associated segment 4 being inserted in a suitable manner in each sawtooth-shaped recess 10. The attachment of the segments 4 on the roller body 2 can be in one of the forms described (by means of clamping screws or fastening screws) or in any other suitable Way. Profiling the outer circumferential side of the roller base body 2 and the matching profile of the inside of each segment 4 has the advantage that the roller shell firmly clamped on the roller base body is reliably and non-rotatably fixed on this roller base body.

As has already been mentioned at the beginning, the sheet metal strips 5 made of the softer material can be made very differently and can also be cast in the cast material of the segments 4. A number of possibilities for this can be seen in FIGS. 2 and 5-11.

2, the metal strips 5 are designed as straight, flat (flat) metal strips which extend parallel to the longitudinal axis 1 a of the roller over the entire axial length (working length) L of the roller shell 3.

Also in the example of FIG. 5, the sheet metal strips 5a cast in segment 4 are straight and run parallel to the longitudinal axis of the roll. In this case, however, the sheet metal strips 5a only extend over part of the axial length L of the roll shell, in such a way that in the peripheral sections of the segment 4 containing the sheet metal strips 5a, two such sheet metal strips 5a with an axial spacing from one another in a peripheral section Axial extension lie one behind the other, while in the peripheral sections immediately adjacent in the circumferential sections only one such sheet metal strip 5a is arranged approximately in the central longitudinal section of the roll shell or its segment 4. The sheet metal strips 5a are thus approximately staggered or in a gap with one another in adjacent circumferential sections.

In the example in FIG. 6, sheet metal strips 5a of the same type and of the same size as in the previous example (FIG. 5) are provided, but these sheet metal strips 5a are parallel to one another both in the circumferential direction and in the direction of the roll longitudinal axis in the adjacent circumferential sections of the segment 4 lie, and wherein in each corresponding circumferential section two such straight metal strips 5a are arranged one behind the other in axial extension.

According to the example in FIG. 7, in each case a plurality of straight sheet metal strips 5b aligned in the axial extension and parallel to the longitudinal axis of the roll are provided in the adjacent circumferential sections of the segment 4, but of significantly shorter length than in the previous examples. In addition, the sheet metal strips 5b which are cast into one another directly adjacent peripheral sections are staggered or arranged in a gap with one another and arranged such that the sheet metal strips 5c of a plurality of adjacent peripheral sections of the individual segments 4 form a relatively flat arrow shape.

Fig. 8 shows a further embodiment with straight, flat sheet metal strips 5c, the length of which corresponds only to a part of the axial length L of the segments 4 or the roll shell. In each circumferential section of the segments 4 containing sheet metal strips 5c, two such sheet metal strips 5c are in turn arranged approximately in the direction of the roll longitudinal axis. In each of these circumferential sections, however, there is one sheet metal strip 5c in one direction and the second sheet metal strip 5c in the opposite direction with respect to the longitudinal axis of the roll indicated by dash-dotted lines in FIG. 1a inclined, ie the two axially arranged sheet metal strips 5c of each corresponding circumferential section are inclined approximately opposite to each other in such a way that - as shown in FIG. 8 - they form an approximately flat arrow shape, with their adjacent ends touching or - as illustrated - one have an axial distance from each other.

The example of FIG. 9 also shows an arrangement of two sheet metal strips 5d in principle in the same way as in FIG. 8, in this case. In this case, however, the sheet metal strips 5d cast into the individual segments 4 are each designed such that they have a lengthwise direction have a corrugated shape, with otherwise approximately the same flat arrow shape arrangement as was explained previously with reference to FIG. 8.

Fig. 10 further illustrates an embodiment in which the sheet metal strips 5e of each jacket segment 4 also have a corrugated shape in their longitudinal direction, but only a single such corrugated sheet metal strip 5e is arranged in each corresponding peripheral section of the segment 4, which is substantially in the direction of the Roll longitudinal axis 1a extends and extends over most of the axial length of the roll shell or from its segment 4.

Finally, FIG. 11 shows another example, according to which the sheet metal strips 5f in turn extend over approximately the largest part of the axial length L of the roll shell 3 and are arranged in the circumferential direction at substantially equal distances from one another. The special feature of this design is the fact that all sheet metal strips are of the same design 5f - as shown in FIG. 11 - have a flat bend, preferably a symmetrical, approximately arrow-like flat angle shape. Each sheet metal strip 5f thus encloses a relatively obtuse angle α (similarly to the sheet strips 5c in FIG. 8 and 5d, respectively, which are axially one behind the other as in FIG. 9). The vertices 5f - of each obtuse angle thus formed lie approximately on the axial longitudinal center of the roll shell 3 and, depending on the application, can point in the direction of rotation or opposite to the direction of rotation of the associated roll.

The grinding roller designed according to the invention is particularly well suited for use in a material bed roller mill of the type indicated at the outset, so that the brittle ground material to be comminuted can be drawn in particularly well and uniformly by the two grinding rollers arranged in the material bed roller mill.

Claims (13)

1. Grinding roller, particularly for use in a material bed roller mill, in which brittle material for grinding is crushed between two grinding rollers which are pressed against one another with high pressure, comprising a basic roller body (2) and a roller shell (3) composed of individual segments (4), the segments being clamped to the basic roller body, characterised in that several sheets (5) which consist of a softer material than the cast material are cast into each segment (4) of the roller shell (3) which is made largely of hard cast material, the said sheets being arranged so as to be peripherally spaced from one another, running substantially at right angles to the shell surface (3a) and aligned approximately radially with respect thereto.
2. Grinding roller as claimed in claim 1, characterised in that the sheets (5) are constructed in the form of sheet metal strips which run approximately transversely.
3. Grinding roller as claimed in claim 2, characterised in that the sheet metal strips (5) extend over the entire axial length (L) of the roller shell (3).
4. Grinding roller as claimed in claim 3, characterised in that the sheet metal strips (5a, 5b, 5c) in each case extend over only a part of the axial length (L) of the roller shell (3).
5. Grinding roller as claimed in claim 4, characterised in that in the peripheral sections of the individual segments (4) containing the sheet metal strips (5a, 5b, 5c, 5d), in each case several sheet metal strips are arranged substantially behind one another in the direction of the longitudinal roller axis (1a).
6. Grinding roller as claimed in claim 5, characterised in that the sheet metal strips (5a, 5b) of each corresponding peripheral section lie behind one another in straight axial extension.
7. Grinding roller as claimed in claim 5, characterised in that the sheet metal strips (5a, 5b) of each corresponding peripheral section lie axially behind one another approximately in echelon formation.
8. Grinding roller as claimed in claim 5, characterised in that the sheet metal strips (5c, 5d) of each corresponding peripheral section are inclined with respect to one another in approximately opposite directions - with respect to the longitudinal roller axis (1a) - and are arranged axially behind one another so that they form a flat arrow shape.
9. Grinding roller as claimed in claim 2, characterised in that the sheet metal strips (5, 5a, 5b, 5c) are constructed so that they run straight and flat.
10. Grinding roller as claimed in claim 2, characterised in that the sheet metal strips (5d, 5e) have an approximately corrugated shape in their longitudinal direction.
11. Grinding roller as claimed in claim 1, characterised in that the sheet metal strips (5f) which extend at least over the greater part of the axial length (L) of the roller shell (3) and are arranged with substantially equal peripheral spacing between them have a flat bend, preferably a symmetrical, approximately arrow-shaped angular form.
12. Grinding roller as claimed in claim 1, characterised in that the radial height (h) of the sheets (5) cast into the segments (4) corresponds approximately to a predetermined wear layer thickness of the roller shell (3).
13. Grinding roller as claimed in claim 1, characterised in that the cast material of the segments (9) is a chill casting and the cast sheets (5) are produced from substantially non-hardenable steel, particularly structural steel.

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