EP3990190B1 - Roller mill with border elements and method of adjusting a frontal gap in the roller mill - Google Patents

Description

The invention relates to a roller mill with edge elements and a method for adjusting a front gap of the roller mill.

Roller mills are usually used to crush grist, such as limestone, clinker or similar rocks. During the comminution of ground material in a roller mill, it can happen that ground material emerges laterally from the grinding gap without having passed through the grinding gap completely or at all. This leads to a reduction in the throughput of the machine and an increase in the grinding circuit circulation, which is associated with an enormous amount of energy.

In order to influence the lateral outflow of ground material from a grinding gap formed between the grinding rollers of a roller mill in a controlled manner, it is known to arrange edge elements on one of the grinding rollers. Such a roller mill with edge elements is, for example, from DE 20 2014 006 837 U1 known. A grinding roller with a device for laterally limiting and sealing the roller gap is in DE 4037816 A1 disclosed.

When operating the roller mill with different types of rock with different grain sizes, there is often an increased flow of material from the grinding gap. In addition, a commonly occurring misalignment of the grinding rollers causes different levels of wear on the edge elements.

Proceeding from this, it is the object of the present invention to provide a roller mill that compensates for wear on the edge elements and can be operated with different types of rock and thus reduces the maintenance costs of the roller mill and optimizes the grinding process.

According to the invention, this object is achieved by a roller mill having the features of independent device claim 1 and by a method according to method claim 10 . Advantageous developments result from the dependent claims.

A grinding roller of a roller mill comprises a roller body and a rim member which is attached to an end portion of the roller body of the grinding roller and extends in the radial direction beyond the surface of the roller body of the grinding roller. The edge member includes a base flange and a spacer member attached thereto, wherein a plurality of wear protection members are attached to the spacer member and wherein the spacer member is mounted between the wear protection member and the base flange.

The edge element preferably extends 10 to 40 cm, preferably 15 to 30 cm, in particular 20 to 25 cm beyond the surface of the roller base body, in particular the grinding surface. The grinding surface is preferably the lateral surface of the cylindrical roller base body. The grinding surface is preferably provided with a plurality of, in particular pin-shaped, wear protection elements.

The base flange is preferably designed as an annular plate, which comprises a steel, for example, and is fastened, in particular welded, to the roller base body. For example, the base flange is formed in one piece with the roller body, for example cast. The spacer element is fitted between the wear protection element and the base flange. The spacer element is preferably made of steel, plastic, brass or copper. The spacer element is attached to the side face of the base flange that points inwards in the axial direction of the grinding roller.

The spacer element between the base flange and the wear protection element provides a distance between the wear protection element and the base flange, which can be adjusted via the selected thickness of the spacer element. The spacer element has, for example, a thickness of 0.1 mm to 40 mm, preferably 5 mm to 30 mm, in particular 20 mm.

The edge element is, for example, detachably connected to the main roller body of the grinding roller. The grinding roller preferably comprises a drive shaft for driving the grinding roller, on which the roller base body is arranged. A detachable arrangement of the edge elements on the roller body offers the advantage of quick and easy replacement of the edge elements in the event of wear. The edge elements are, for example, glued, soldered, welded or screwed onto the roller body.

According to a first embodiment, the spacer element is detachably attached to the base flange. For example, the spacer element is attached to the base element using screws or bolts. A plurality of spacer elements are preferably arranged next to one another on the base flange and are each attached to the base flange using a detachable connecting means such as a screw or bolt. A detachable attachment of the spacer element to the base flange enables the spacer element to be easily replaced. For example, the spacer element is exchanged to increase or decrease the distance between the wear protection element and the base flange.

According to a further embodiment, the spacer element is plate-shaped. According to a further embodiment, the spacer element is designed in the shape of a circular ring or part of a circular ring. Exactly one or a plurality of spacer elements is attached to the base element, for example.

According to a further embodiment, the base flange is designed as a circular plate. The base flange is preferably firmly connected to the roller base body, in particular welded or formed in one piece with it.

According to a further embodiment, the wear protection elements are detachably attached to the spacer element. The wear protection elements are preferably fastened to the respective spacer element by means of a detachable connecting element, such as a screw or a bolt. A detachable connection of the wear protection elements allows easy replacement of the wear protection elements, for example in the event of wear.

According to a further embodiment, the base flange is detachably connected to the main roller body of the grinding roller. The base flange is preferably fastened to the round roller body by means of screws or bolts. For example, the base flange is at least partially attached to the end face of the roller body. A detachable connection of the base flange to the roller body enables the complete edge element to be exchanged in a simple manner.

The invention also includes a roller mill having a first grinding roller and a second grinding roller, which are arranged opposite one another and can be driven in opposite directions, with at least one grinding roller being designed as described above. A grinding gap is formed between the grinding rollers, with the edge element being formed in such a way that it extends across the grinding gap and at least partially covers the opposite grinding roller at the front. It is also conceivable that each of the grinding rollers has exactly one edge element. Each of the grinding rollers has in particular a first end area and a second end area, the first grinding roller having an edge element at its first end area which covers the first end area of the second grinding roller in the area of the grinding gap at the front. The second grinding roller preferably has an edge element on its second end area, which frontally covers the second end area of the first grinding roller in the area of the grinding gap. In particular, the edge elements are arranged diagonally opposite with respect to the end regions of the grinding rollers. In a further embodiment, only one grinding roller has two edge elements which are attached to opposite ends of the grinding rollers, the opposite grinding roller having no edge element. Between the edge elements and the end face of the opposite grinding roller in each case, an end gap is preferably formed in each case. A gap at the end prevents the edge element from colliding with the end region of the respectively opposite grinding roller in the event of the grinding rollers running out of alignment, with the grinding rollers lying opposite one another not being arranged parallel to one another. In the case of a parallel arrangement of the opposite grinding rollers to one another, the gap at the front serves to reduce wear on the edge elements.

The edge elements preferably cover the opposite grinding rollers by about 2-10%, in particular 4-7%, preferably 5% of the roller diameter. The overlap means the area of the opposite grinding roller along which the edge element extends in the radial direction. If the overlap is too small, the material will flow past the edge elements, while if the overlap is too large, this will lead to a collision if the grinding rollers are misaligned. An overlap of the edge elements of about 2-10%, in particular 4-7%, preferably 5% of the roller diameter offers an optimal overlap, with collision and flow of the material over the edge elements being avoided. The grinding rollers of the roller mill are preferably of identical construction. This offers the advantage of easy exchangeability of the grinding rollers in the event of maintenance and enables time and cost savings.

The invention also includes a method for adjusting a front gap of a roller mill with a first grinding roller and a second grinding roller, which are arranged opposite one another and can be driven in opposite directions. A grinding gap is formed between the grinding rollers, with each of the grinding rollers having an edge element at an end region of a respective roller end, which is designed in such a way that it extends across the grinding gap and at least partially covers the opposite grinding roller on the front side, so that between the edge element and the front side a gap is formed at the end of the respectively opposite grinding roller. The edge member has a base flange. The procedure for adjusting the face gap includes the steps:
attaching a spacer to the base flange; and attaching a plurality of antiwear elements to the spacer, wherein the spacer is attached between the antiwear element and the base flange.

The advantages described with reference to the grinding roller apply to the method for setting a gap at the front in a process-related correspondence. The method described is preferably used to adjust the width of the gap at the end, the width of the gap at the end preferably being dependent on the thickness of the spacer element. The spacer element is attached in particular to the side surface of the Base flange attached so that the width of the face gap is reduced. Each edge element of the roller mill preferably has an identical spacer element, so that the front-side gaps of a grinding roller preferably have the same width. It is also conceivable that a plurality, for example two or three, spacer elements are attached next to one another in the axial direction on a respective base flange.

According to one embodiment, the spacer element and the wear protection elements are detachably fastened to the base flange. The spacer element is preferably attached to the base flange by means of screws or bolts. The wear protection elements are preferably each attached to the spacer element by means of detachable fastening means such as screws. For example, the plurality of spacer elements are screwed together and to the base flange.

An edge element as described above with a spacer element and a plurality of wear protection elements offers the advantage of easy adjustability of the front gap, so that, depending on the application, a spacer element with a corresponding thickness can be easily attached to the base flange and the desired front gap is thus set.

Description of the drawings

• Fig. 1 zeigt eine schematische Darstellung einer Walzenmühle mit zwei jeweils ein Randelement aufweisenden Mahlwalzen gemäß einem Ausführungsbeispiel.
• Fig. 2 zeigt eine schematische Darstellung einer Walzenmühle, wobei eine Mahlwalze zwei Randelemente aufweist gemäß einem weiteren Ausführungsbeispiel.
• Fig. 3 zeigt eine schematische Darstellung einer Mahlwalze mit zwei Randelementen in einer perspektivischen Ansicht und einer Draufsicht gemäß einem weiteren Ausführungsbeispiel.

The invention is explained in more detail below on the basis of several exemplary embodiments with reference to the attached figures.

• 1 shows a schematic representation of a roller mill with two grinding rollers, each having an edge element, according to an exemplary embodiment.
• 2 shows a schematic representation of a roller mill, wherein a grinding roller has two edge elements according to a further embodiment.
• 3 shows a schematic representation of a grinding roller with two edge elements in a perspective view and a top view according to a further embodiment.

1 shows a roller mill 10 with a first grinding roller 12 and a second grinding roller 14, each of which has a substantially cylindrical roller body. The grinding rollers 12, 14 are arranged opposite one another and can be driven in opposite directions. A grinding gap 16 is formed between the grinding rollers 12, 14 and extends in the axial direction. The grinding rollers 12, 14 are arranged parallel to one another, so that the grinding gap 16 extending between the grinding rollers 12, 14 has a constant width. Each of the grinding rollers 12, 14 also has a drive shaft 30, 32 which extends through the respective grinding roller 12, 14 along the central axis and drives the grinding rollers to rotate about its central axis. The first and the second grinding roller 12, 14 have the same diameter and the same length and are of essentially identical construction.

The grinding rollers 12, 14 each have a first end region 24, 28 and a second end region 22, 26 which are arranged at opposite ends of the grinding roller. The first end area 24 of the first grinding roller 12 is arranged opposite the first end area 28 of the second grinding roller 14 , the second end area 22 of the first grinding roller 12 being arranged opposite the second end area 26 of the second grinding roller 14 .

The roller mill 10 also has a first edge element 18 and a second edge element 20, one edge element 18, 20 being arranged on each grinding roller 12, 14 in each case. The edge elements 18, 20 are arranged diagonally opposite one another in relation to the end regions 22 to 28 of the grinding rollers 12, 14. The first grinding roller 12 has at its first end area 24 an edge element 18 which extends in the radial direction over the grinding gap 16 and partially covers the end face of the second grinding roller 14 at the first end area 28 . The second grinding roller 14 has at its second end area 26 an edge element 20 which extends in the radial direction over the grinding gap 16 and partially covers the end face of the first grinding roller 12 at its second edge area 22 . The second edge member 20 is referenced arranged on the first edge element 18 at the diagonally opposite end region 26 of the second grinding roller 14 . The grinding rollers 12, 14 are offset in the axial direction, so that a first end-side gap 34 is formed between the first edge element 18 and the end face of the second grinding roller 14, and a second end-side gap is formed between the second edge element 20 and the end face of the first grinding roller 12 36 is formed. The first and the second end gap 34, 36 each extend in the radial direction.

Each grinding roller 12, 14 comprises a preferably cylindrical roller body 11, 13, which has a grinding surface formed by the cylindrical surface of the roller body. The edge elements 18, 20 each comprise, for example, a circumferential circular ring which is attached to the respective grinding roller 12, 14 in a manner that is not shown. For example, the edge elements 18, 20 are attached to the end face or to the outer circumference of the grinding roller, in particular the respective roller body. On the outer circumference of the respective grinding roller 12, 14, for example, a circumferential groove is arranged, in which a respective edge element 18, 20 is arranged. The edge elements 18, 20 are made of a wear-resistant material, such as steel, and have a thickness of 10 mm to 100 mm, for example, and cover the opposite grinding rollers 12, 14 by about 2-10%, in particular 4-7%, preferably 5 % of roll diameter.

2 shows a roller mill 10 with a first grinding roller 12 and a second grinding roller 14 according to the embodiment 1 . In contrast to 1 the first grinding roller 12 has two edge elements 18, 20 which are each attached to an end region of the grinding roller 12. The first edge element 18 is attached to the first edge area 22 of the first grinding roller 12 and extends in the radial direction across the grinding gap 16 so that it partially covers the end face of the second grinding roller 14 at the first end area 26 . The second edge element 20 is attached to the second end area 24 of the first grinding roller 12 and extends in the radial direction across the grinding gap 16, so that the end face of the second grinding roller 14 faces the second end area 28 partially covered. Between the edge elements 18 and the respective end face of the second grinding roller 14 a respective end face gap 34, 36 is formed.

3 shows a grinding roller, for example the first grinding roller 12 of FIG figures 1 and 2 , with two edge elements 18, 20. Each of the edge elements 18, 20 includes a base flange 38 which is, for example, an annular plate. The base flange 38 is preferably formed in one piece from steel, for example, and is attached to the roller base body of the grinding roller 12, in particular welded or formed in one piece with it, in particular cast. A spacer element 40 is attached to the base flange 38 . The spacer element 40 is designed, for example, as a circular plate. It is also conceivable that the spacer element 40 has a plurality of segments in the shape of part circular rings, which preferably together form a circular ring and are attached next to one another on the base flange. The spacer element 40 is preferably made of steel, plastic, brass or copper. The spacer element 40 is, for example, releasably attached to the base flange by means of a non-positive and/or positive connection means. For example, the spacer element 40 is attached to the base flange 38 by means of one or a plurality of screws. The spacer element 40 is attached to the side surface pointing inwards in the axial direction of the grinding roller 12 and covers it completely, for example.

A plurality of wear protection elements 42 are attached to the spacer element 40 . The wear protection elements 42 are, for example, plate-shaped and made of a wear-resistant material, such as tungsten carbide or ceramic. The wear protection elements 42 are preferably attached to the spacer element 40 next to one another, so that the surface of the spacer element 40 pointing inwards in the axial direction of the grinding roller 12 is preferably completely covered by one or a plurality of wear protection elements 42 . The wear protection elements 42 are fastened to the spacer element 40, for example by means of a detachable connection means, such as screws or bolts.

By way of example, the grinding roller 12 has an edge protection 44 which preferably comprises a plurality of corner blocks which are fitted, for example, in a circumferential groove on an end region of the grinding roller. The edge protection 44 is preferably in contact with the wear protection elements 42 .

A spacer element 40 enables a simple adjustment of the end gap 34, 36 of the roller mill 10, in particular without an axial displacement of the grinding rollers 12, 14 relative to one another. A spacer element 40 with a corresponding thickness is attached to the base flange 38 in order to adjust the gap 34, 36 on the end face. Then, for example, the wear protection elements 42 are attached to the spacer element 40 . In order to achieve a further enlargement or reduction of the end gap 34, 36, an axial displacement of at least one of the grinding rollers 12, 14 relative to the other grinding roller 12, 14 is possible.

Reference List

10

roller mill

11

roller body

12

first grinding roller

13

roller body

14

second grinding roller

16

milling gap

18

first boundary element

20

second boundary element

22

second end area of the first grinding roller

24

first end area of the first grinding roller

26

second end area of the second grinding roller

28

first end portion of the second grinding roller

30

Drive shaft of the first grinding roller

32

Drive shaft of the second grinding roller

34

first frontal gap

36

second front gap

38

base flange

40

spacer element

42

anti-wear element

44

edge protection

Claims (11)

1. Milling roll (12, 14) of a roll mill (10) having a roll main body (11, 13) and an edge element (18, 20) which is attached to an end region (22, 24, 26, 28) of a roll end of the milling roll (12, 14) and extends in the radial direction beyond the surface of the roll main body (11, 13),
   wherein the edge element (18, 20) comprises a base flange (38) and a spacer element (40) which is attached thereto, wherein a plurality of wear protection elements (42) are attached to the spacer element (40), characterised in that the spacer element (40) is attached between the wear protection element (42) and the base flange (38).
2. Milling roll (12, 14) according to claim 1, wherein the spacer element (40) is fastened releasably to the base flange (38).
3. Milling roll (12, 14) according to any one of the preceding claims, wherein the spacer element (40) is plate-shaped.
4. Milling roll (12, 14) according to any one of the preceding claims, wherein the base flange (38) is configured as a circular ring-shaped plate.
5. Milling roll (12, 14) roll mill (10) according to any one of the preceding claims, wherein the spacer element (40) is configured as a circular ring-shaped plate.
6. Milling roll (12, 14) according to any one of the preceding claims, wherein the spacer element (40) is configured as a partially circular ring-shaped plate, and a plurality of spacer elements (40) are attached to the base flange (38).
7. Milling roll (12, 14) according to any one of the preceding claims, wherein the wear protection elements (42) are attached releasably to the spacer element (40).
8. Milling roll (12, 14) according to any one of the preceding claims, wherein the base flange (38) is connected releasably to the roll main body (11, 13) of the milling roll (12, 14).
9. Roll mill (10) having

   a first milling roll (12) and a second milling roll (14) which are arranged opposite one another and can be driven in opposite directions, wherein at least one milling roll (12, 14) is configured according to any one of the preceding claims,

   wherein a milling gap (16) is formed between the milling rolls (12, 14) and wherein the edge element (18, 20) is configured in such a way that it extends over the milling gap (16) and at least partially covers the end face of the opposite milling roll (12, 14).
10. Method for setting an end-face gap (34, 36) of a roll mill (10) having a first milling roll (12) and a second milling roll (14) which are arranged opposite one another and can be driven in opposite directions,

    wherein a milling gap (16) is formed between the milling rolls (12, 14) and

    wherein each of the milling rolls (12, 14) has, on an end region (22, 24, 26, 28) of a respective roll end, an edge element (18, 20) which is configured in such a way that it extends over the milling gap (16) and at least partially covers the end face of the opposite milling roll (12, 14), with the result that an end-face gap (34, 36) is formed between the edge element (18, 20) and the end face of the respective opposite milling roll (12,14), and wherein the edge element (18, 20) has a base flange (38),

    comprising the steps of: attaching a spacer element (40) to the base flange (38), and attaching a plurality of wear protection elements to the spacer element (40), wherein the spacer element (40) is attached between the wear protection element (42) and the base flange (38).
11. Method according to claim 10, wherein the spacer element (40) and the wear protection elements (42) are fastened releasably.

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