EP4135901A1

EP4135901A1 - Key milling plate segment, milling plate segment system, and method for same

Info

Publication number: EP4135901A1
Application number: EP20720400.9A
Authority: EP
Inventors: Jörg BETTENWORTH; Michael Keyssner
Original assignee: Loesche GmbH
Current assignee: Loesche GmbH
Priority date: 2020-04-16
Filing date: 2020-04-16
Publication date: 2023-02-22
Anticipated expiration: 2040-04-16
Also published as: AU2020442474B2; ZA202211068B; US20230191418A1; MX2022012993A; BR112022020930A2; AU2020442474A1; CN115515716A; JP7427807B2; JP2023529059A; CN115515716B; WO2021209133A1; EP4135901B1

Abstract

The invention relates to a replaceable key milling plate segment for a milling path of a milling plate of a rolling mill, having a ring-like shape with an outer circumference and an inner circumference about a center. The length of the key milling plate segment inner edge lying closer to the center is greater than the length of the outer edge lying remotely from the center. The invention additionally relates to a milling plate segment, a rolling mill, and a method for replacing milling plate segments.

Description

KEY GRINDING DISC SEGMENT GRINDING DISC SEGMENT SYSTEM AND PROCEDURE FOR IT

The invention relates to a key grinding table segment for a grinding track of a grinding bowl of a roller mill. Here, the grinding track has a ring-like shape with an outer circumference and a smaller inner circumference around a center point. The exchangeable key grinding table segment has an outer edge and an inner edge as well as two connecting edges connecting the outer and inner edges.

The invention also relates to a grinding table segment system for a grinding path of a grinding table of a roller mill with several equally sized, identically shaped standard grinding table segments which each have an inner edge and an outer edge which are connected by two connecting edges. The length of the inner edge is less than the length of the outer edge.

Finally, the invention relates to a method for removing Mahltel lersegmenten from a grinding table with a grinding table segment system.

Common roller mills have a grinding table which rotates under the stationary, rotatably mounted grinding rollers. The grinding table has a grinding track on which the grinding rollers roll. Between the grinding table or the grinding track and the grinding rollers, there is ground material to be comminuted during operation. The grinding rollers work by their own weight, but are sometimes also subjected to additional force so that they press on the grinding track and thus on the grinding table. During operation, the forces that occur like the material abrasion caused by grinding stock, wear on the one hand on the grinding rollers and on the other hand on the grinding track. This is why the grinding track in most roller mills is designed to be interchangeable.

The ring-shaped grinding track usually has exchangeable segments of the same size, which have a shape similar to a piece of cake. This means that they are designed like a trapezium and have a greater length on their outer edge than on their inner edge. Exactly describes both the outer edge and the inner edge an arc shape, which is due to the annular design of the grinding track be. However, it is also possible to train the inner and outer edges straight, so that the grinding track forms a polygonal shape which approximates a ring shape. A grinding table is often also referred to as a grinding bowl. In a similar way, the grinding table segments are also referred to as grinding table plates or plate segments. The grinding table segments are also often referred to as grinding plates or grinding bowl armor.

The problem with common grinding table segment systems is their replacement.

During operation, the rolling of the grinding rollers on the grinding track in the space between the segments, that is, the area in which two neighboring segments touch, is pressed in to the grinding material. Although attempts are of course made to make this edge as small and small as possible, the considerable forces that occur during the grinding process cannot prevent regrind from penetrating there, in particular regrind that is already very small. Due to the forces during the grinding, this penetrated grist is solidified and very strongly compressed and thus hard.

To replace the grinding plates, it is now necessary to first remove one segment, then the other segments. However, this first segment cannot be drawn inwards, as this is not geometrically possible due to the standard design with a larger outer edge and a smaller inner edge. Due to the construction of most grinding tables, it is normally not possible to push outwards from the grinding table. Conventionally, attempts have been made to lift the grinding table segment upwards by removing a clamping rings, with which the grinding table segments are attached to the grinding table, an attempt is made to press against it from below.

However, this is very difficult due to the pressed-in grinding material, so that an expansion of the first segment often takes several hours or even days. It is not uncommon for even the edge or the joint between two adjacent grinding table segments to be cut by means of flame cutting with the help of a so-called. Gouging is processed.

Generic grinding table segments emerge from DE 1507629 or DE 1507580, for example.

The invention is therefore based on the object of specifying a grinding table segment, a grinding table segment system and a method for exchanging grinding table segments which facilitate the exchange process.

According to the invention, this object is achieved by a key grinding table segment with the features of claim 1, a grinding table segment system with the features of claim 6 and a method with the features of claim 15.

Advantageous embodiments of the invention are specified in the subclaims and in the description as well as the figures and their explanation.

In the case of the key grinding table segment according to the invention, it is provided that the length of the inner edge located closer to the center point is greater than the length of the outer edge located further away from the center point.

The invention is based on the basic idea of deviating from the previously classic form used. Because the exchangeable key grinding table segment is dimensioned in such a way that it no longer jams itself when it is pushed towards the center of the grinding table due to its geometric shape, it is possible to remove the key grinding table segment in this way.

Another advantage of this construction is that the gap between the key grinding table segment and its connecting edges to the neighboring grinding table segments automatically increases, and thus the problems are minimized by solidified regrind or do not come into play in this form.

It is advantageous if the outer edge of the key grinding table segment forms an arc on the outer circumference and the inner edge of the key grinding table segment forms an arc on the inner circumference of the grinding table. In other words, the key grinding table segment fits with its dimensions on the grinding path of the grinding table, although the tip is missing.

Furthermore, the length of a circular arc which is formed by the key grinding table segment can decrease with the increase in the radius from the nenkante in to the outer edge. With its shape, the key grinding tray segment represents an inverted cake-like shape.

It is preferred if a press recess for attaching a press for the replacement process is provided on the outer edge of the key grinding table segment. A pressing tool can be attached by means of this press recess and the key grinding table segment can be pressed in the direction of the center point of the grinding table. The press tool can be placed between the press recess and the edge of the main body of the grinding table.

In an advantageous embodiment, the press recess is designed in such a way that it can be covered by a retaining edge component during operation. This means that it is designed in such a way that the construction prevents crushed ground material from being pressed into the press recess as far as possible.

In the context of the invention, the expression “in operation” can be understood to mean an operational roller mill. This means in particular that the grinding table is built up at least on the mill side, that is, a grinding track with a damming edge is present.

The invention also relates to a grinding table segment system for a grinding path of a grinding table of a roller mill with a plurality of grinding table segments which each have a nenkante in and an outer edge. The two edges are connected by two connecting edges. The length of the inside edges is less than the length the outer edge. This means that the standard grinding table segments have a shape similar to a piece of cake, but with the point missing.

According to the invention it is provided that the grinding table segment system further comprises at least one key grinding table segment according to the invention and at least one compensating grinding table segment which is arranged next to the key grinding table segment.

The provision of a key grinding plate segment in a grinding table segment makes it possible for the grinding plate, which is built up from the grinding table segment, or the rolling surface of the rollers to be replaced relatively easily without the need for time-consuming removal, as previously described in the prior art and crushing material from the joints is necessary.

It is advantageous if the grinding plate segments are designed as standard grinding plate segments of the same size and shape, and the key grinding plate segment and the at least one compensating grinding plate segment together form the shape of one or more standard grinding plate segments.

With this dimensioning of the exchangeable key grinding table segment and the provision of a compensating grinding table segment, which together form the shape of one or more standard grinding table segments, it can be achieved that all other standard grinding table segments can be made the same. This facilitates storage and makes it possible that few different grinding table components have to be kept available. Conventional segments can also continue to be used for this purpose.

Grinding table segments can also be referred to as grinding plates.

Two equalizing grinding table segments are preferably provided in an arrangement to the left and right of the key grinding table segment. Here, the two compensating grinding table segments can be designed essentially mirror-symmetrically to an axis on the radius of the grinding table through the key grinding table segment. This axis can, for example, be the axis of symmetry on the radius of the key grinding table segment. Such a construction makes it possible in a simple manner to achieve the size of one or more standard grinding table segments with a key grinding table segment and two compensating grinding table segments. This is further simplified by the provision of mirror-symmetrical compensating grinding plate segments.

It is preferred if two compensating grinding plate segments with the key grinding plate segment are the size of one, two or three standard grinding plate segments.

In another embodiment, the grinding plate segments can also be designed as equal grinding plate segments. In this case it is provided that several key grinding plate segments are present. It is preferred here that the same number of equalizing grinding plate segments and key grinding plate segments are provided. In other words, a key grinding tray segment is followed by a compensating grinding tray segment. In this respect, standard grinding segments, as described above, are no longer used. One can, according to this embodiment, the compensating grinding plate segments as a combination, as described in the previous embodiment, of standard grinding plate segments with balancing grinding plate segments, provided they are made in one piece. In this case it is only necessary to have two different types of Mahltellerseg.

Another advantage results from the fact that several key grinding table segments are provided, so that it is irrelevant in which position the grinding table has come to a standstill in relation to the grinding rollers arranged above. Otherwise, care must be taken that the key grinding table segment does not come to rest in the area of a roller, since dismantling is then complicated and ideally the bowl must be turned further.

It is advantageous if the grinding table segments, that is to say the standard grinding table segments, the key grinding table segment or segments and / or the compensating grinding table segments can be fastened to the grinding table by means of a one-piece or multi-part clamping ring. According to the design, it is provided that the clamping ring on the inner circumference of the grinding track, i.e. on the inner edge of the grinding lersegmente abuts and so presses the grinding table segments outward against an edge of the grinding table base body.

The invention also relates to a roller mill with a grinding table, the Mahltel ler having a grinding table segment system according to the invention.

Such a roller mill has the advantage that when the grinding track, that is to say the individual grinding table segments, are replaced and new ones are installed, this can be carried out significantly more quickly than with conventional grinding table segments. This is due to the fact that the key grinding table segment can be removed very easily from the grinding track and it is hardly necessary for the ground material that has accumulated on the edge between the key grinding table segment and the neighboring segments to close before the key grinding table segment is removed remove.

Finally, the invention relates to a method for removing a Mahltel lersegmentes from a grinding path of a grinding table of a roller mill with a grinding table segment system according to the invention. It is provided that the clamping ring and the retaining ring are removed from the grinding table first. The press recess of the key grinding table segment according to the invention is now open. Now a press tool can be placed on the press recess and the key grinding table segment can be pressed towards the center of the grinding table. The main body of the grinding table serves as a counter-bearing.

The space in which the key grinding table segment is pressed was previously occupied by the clamping ring. After the key grinding tray has been removed, the remaining grinding tray segments can be removed. Here, too, it is no longer necessary to first clean the edge or the groove between two adjacent grinding plate segments from solidified grinding material, since there is always no further grinding plate segment on one side, so that there is enough room for easy sliding on this side.

The invention is explained below using a schematic exemplary embodiment and with reference to the figures. Here show: Fig. 1 is a schematic plan view of a grinding table with a grinding track accordingly a first embodiment;

2 shows a schematic plan view of a grinding table with a grinding path according to a second embodiment; and

3 shows a sectional view through a grinding table with a grinding track.

In Fig. 1 is a schematic representation of a plan view of a grinding table 4 with egg ner grinding track 5 according to a first embodiment. The grinding track 5 is built up from a key grinding plate segment 10, two mirror-symmetrically shaped compensation grinding plate segments 11 and ten standard grinding plate segments 12.

The key grinding table segment 10 has an outer edge 31, an inner edge 32 and two lateral connecting edges 33. In a similar way, the standard grinding table segments 12 also have an outer edge 41, an inner edge 42 and two connecting edges 43. The same is also the case with the two compensating grinding table segments 11, which have an outer edge 51, an inner edge 52 and two connecting edges 53. As shown in FIG. 1, the outer edge 31 of the key grinding table segment 10 according to the invention has a shorter length than its inner edge 32. As a result, the key grinding table segment 10 can be pushed inward in the direction of the grinding table center 6.

As can be seen by those skilled in the art, this offers the advantage that by sliding the key grinding table segment 10 inward, the free space between the connecting edges 33 of the key grinding table segment 10 and the adjacent connecting edges 53 of the compensating grinding table segments 11 is increased. This also means that ground material pressed into it cannot prevent it from being pushed inwards.

Together with the two adjacent compensating grinding plate segments 11, the key grinding plate segment 10 is the size of two normal standard grinding plate segments 12. So standard elements can be used for the rest of the grinding path. In Fig. 2, an alternative embodiment of the grinding table 5 is shown. In the following, only the differences from the embodiment of FIG. 1 will be discussed. The grinding table 5 according to this embodiment has, for example, six key grinding table segments 10 and, for example, six compensating grinding table segments 11. These are each arranged alternately on the grinding table 5. As can be seen in conjunction with the embodiment from FIG. 1, the standard grinding plate segments 12 are dispensed with here. In contrast to the embodiment of FIG. 1, however, only two different Mahltel lersegmentarten are used. This simplifies storage. Another advantage of this embodiment is that the first key grinding table segment 10, which is removed by being pushed inward in the direction of the grinding table center 6, can be freely selected. This is particularly interesting because, in the worst case, when the mill is stopped, a key grinding plate segment 10 could come to lie exactly under the roller, so that the mill would have to be started up again. In the embodiment according to FIG. 2, this is clearly unlikely, since the pitch of the grinding plate segments is significantly greater than the number of grinding rollers.

3 shows a sectional view through a grinding table 4. Here, a press recess 15 is shown in the right area of the key grinding table segment 10 ge. This is covered by a storage edge 26. The position of the retaining edge 26 ensures that hardly any, or at least very little, material to be ground gets into the press recess 15 during operation, that is to say during the grinding processes.

The key grinding table segment 10 itself is arranged and fastened in a recess in the grinding table body 7 by means of a clamping ring 20.

To install the grinding track 5, the key grinding plate segment 10 is used in this case, then the clamping ring 20 is attached. This is attached by means of a screw 21. Due to the wedge shape, the clamping ring presses the key grinding plate segment 10 against the outer edge of the grinding plate when the screw 21 is tightened. The further grinding table segments 11, 12 are fastened in a similar manner before or afterwards. When removing, proceed in reverse order. In this case, it is essential that the key grinding plate segment 10 is removed first before the other grinding plate segments 11, 12. For this purpose, the screw 21 is first loosened, since the clamping ring 20 can be removed with it. Simultaneously, before or after, the storage ring 26 is also dismantled. A pressing tool can then be used in the press recess 15 and so the key grinding table segment 10 can be pressed into the space in which the clamping ring 20 was previously located. After the key grinding tray segment 10 has been removed, the other Mahltel lersegmente 11, 12 can also be removed relatively easily.

With the key grinding table segment according to the invention, the grinding table segment system according to the invention and the method according to the invention, it is possible to significantly simplify the replacement of grinding table segments of a grinding track of a roller mill and to carry it out in a shorter time.

Claims

PATENT CLAIMS

1. Interchangeable key grinding table segment (10) for a grinding path (5) of a grinding table (4) of a roller mill, the grinding path (5) having a ring-like shape with an outer circumference and a smaller inner circumference around the center point, with an outer edge ( 31) and an inner edge (32) as well as two connecting edges (33) connecting the outer and inner edges, characterized in that the length of the inner edge (32) closer to the center point is greater than the length of the further from the center point of the grinding table (4) distant outer edge (31).

2. Interchangeable key grinding tray segment (10) according to claim 1, characterized in that the outer edge (31) of the key grinding tray segment (10) forms a circular arc on the outer circumference and the inner edge (32) of the key grinding tray segment (10) a Forms circular arc on the inner circumference.

3. Exchangeable key grinding plate segment (10) according to one of claims 1 or 2, characterized in that the length of the circular arc which is formed by the key grinding plate segment (10) increases with the radius of the inner edge (32) to Outer edge (31) reduced.

4. Exchangeable key grinding tray segment (10) according to one of claims 1 to 3, characterized in that a pressing recess (15) for attaching a pressing tool for an exchange process is provided on the outer edge (31).

5. Interchangeable key grinding plate segment (10) according to claim 4, characterized in that the press recess (15) is designed ver coverable during operation of a retaining edge component (26).

6. Grinding table segment system for a grinding path (5) of a grinding table (4) of a roller mill with several grinding table segments (12), each of which has an inner edge

(42) and an outer edge (41), which by two connecting edges

(43) are connected, the length of the inner edge (42) being less than the length of the outer edge (41), characterized by at least one key grinding table segment (10) according to one of claims 1 to 5 and with at least one compensating grinding table segment ( 11), which is arranged next to the key grinding table segment (10).

7. grinding plate segment system according to claim 6, characterized in that the grinding plate segments (12) are designed as standard grinding plate segments (12) of the same size and shape, and that the key grinding plate segment (10) and the at least one compensating grinding plate segment (11) together form the shape of one or more standard grinding plate segments (12).

8. grinding table segment system according to claim 7, characterized in that two compensating grinding table segments (11) are provided in an arrangement to the left and right of the key grinding table segment (10).

9. grinding table segment system according to claim 8, characterized in that, that the two compensating grinding plate segments (11) are essentially mirror-symmetrical to an axis on the radius of the grinding path through the key grinding plate segment (10).

10. grinding table segment system according to one of claims 7 to 9, characterized in that two compensating grinding table segments (11) and a key

Grinding plate segment (10) the size of one, two or three standard grinding plate segments (12).

11. grinding plate segment system according to claim 6, characterized in that the grinding plate segments (12) are formed as a compensating grinding plate segment (11) and that a plurality of key grinding plate segment (10) are provided.

12. grinding plate segment system according to claim 6 or 11, characterized in that the same number of compensating grinding plate segment (11) and key

Grinding table segment (10) are proceeding.

13. Grinding table segment system according to one of claims 6 to 12, characterized in that the key grinding table segment (10), the compensating grinding table segment (11) and / or the standard grinding table segments (12) by means of a one-part or multi-part clamping ring (20 ) can be attached to the grinding table (4).

14. Roller mill with a grinding table (4), characterized in that the grinding table (4) has a grinding table segment system according to one of claims 6 to 13.

15. A method for removing grinding plate segments (10, 11, 12) from a grinding plate (5) with a grinding table segment system according to one of claims 6 to 13, characterized in that that the clamping ring (20) and the retaining ring (26) are removed, that a pressing tool is attached to the pressing recess (15) of the key

Grinding table segment (10) is attached so that the key grinding table segment (10) is pressed in the direction of the grinding table center by means of the pressing tool, and that the further grinding table segments (11, 12) are then removed.