The invention relates to a roll mill with edge elements, and to a method for setting an end-side gap of the roll mill.
Roll mills are usually used for the comminution of material to be milled, such as, for example, limestone, clinker or similar rocks. In the case of the comminution of material to be milled in a roll mill, it can occur that material to be milled escapes laterally out of the milling gap, without having passed the milling gap completely or at all. This leads to the decrease of the throughput capacity of the machine and to the increase of the milling circulations, which is linked with an enormous energy requirement.
For the controlled influencing of the lateral outflow of material to be milled from a milling gap which is configured between the milling rolls of a roll mill, it is known for edge elements to be arranged on one of the milling rolls. A roll mill of this type with edge elements is known, for example, from DE 20 2014 006 837 U1.
In the case of the operation of the roll mill with different rock types with a different grain size, an increased material outflow from the milling gap frequently occurs. In addition, usually occurring skewed running of the milling rolls causes differing wear of the edge elements.
Proceeding herefrom, it is an object of the present invention to provide a roll mill which compensates for wear of the edge elements, can be operated with different rock types, and therefore reduces the maintenance costs of the roll mill and optimizes the milling process.
According to the invention, this object is achieved by way of a roll mill with the features of independent apparatus claim 1, and by way of a method as claimed in method claim 10. Advantageous developments result from the dependent claims.
In accordance with a first aspect, a milling roll of a roll mill comprises a roll main body and an edge element which is attached to an edge region of the roll main body of the milling roll and extends in the radial direction beyond the surface of the roll main body of the milling roll. The edge element comprises a base flange and a spacer element which is attached thereto, a plurality of wear protection elements being attached to the spacer element.
The edge element preferably extends by from 10 to 40 cm, preferably by from 15 to 30 cm, in particular by from 20 to 25 cm beyond the surface of the roll main body, in particular the milling face. The milling face is preferably the circumferential face of the cylindrical roll main body. The milling face is preferably provided with a plurality of, in particular, pin-shaped wear protection elements.
The base flange is preferably configured as a circularly annular plate which comprises, for example, a steel and is fastened to the roll main body, in particular is welded to it. For example, the base flange is configured in one piece with the roll main body, for example is cast. The spacer element is attached between the wear protection element and the base flange. The spacer element is preferably configured from steel, plastic, brass or copper. The spacer element is attached to that side face of the base flange which points inward in the axial direction of the milling roll.
The spacer element between the base flange and the wear protection element ensures a spacing of the wear protection element from the base flange, it being possible for the spacing to be set via the selected thickness of the spacer element. The spacer element has, for example, a thickness of from 0.1 mm to 40 mm, preferably of from 5 mm to 30 mm, in particular 20 mm.
The edge element is connected, for example, releasably to the roll main body of the milling roll. The milling roll preferably comprises a drive shaft for driving the milling roll, on which drive shaft the roll main body is arranged. A releasable arrangement of the edge elements on the roll main body affords the advantage of a rapid and simple exchange of the edge elements in the case of wear. The edge elements are, for example, adhesively bonded, soldered, welded or screwed onto the roll main body.
In accordance with a first embodiment, the spacer element is fastened releasably to the base flange. For example, the spacer element is fastened to the base element via screws or bolts. A plurality of spacer elements are preferably arranged next to one another on the base flange and are fastened to the base flange in each case via a releasable connecting means, such as a screw or a bolt. A releasable fastening of the spacer element to the base flange makes a simple replacement of the spacer element possible. For example, the spacer element is replaced, in order to increase or to decrease the spacing between the wear protection element and the base flange.
In accordance with a further embodiment, the spacer element is of plate-shaped configuration.
In accordance with a further embodiment, the spacer element is of circularly annular or partially circularly annular configuration. Precisely one or a plurality of spacer elements is/are attached to the base element, for example.
In accordance with a further embodiment, the base flange is configured as a circularly annular plate. The base flange is preferably connected fixedly to the roll main body, in particular is welded to or configured in one piece with the latter.
In accordance with a further embodiment, the wear protection elements are attached releasably to the spacer element. The wear protection elements are preferably fastened to the respective spacer element by means of a releasable connecting element, such as a screw or a bolt. A releasable connection of the wear protection elements makes a simple replacement of the wear protection elements possible, for example in a case of wear.
In accordance with a further embodiment, the base flange is connected releasably to the roll main body of the milling roll. The base flange is preferably fastened to the roll round body by means of screws or bolts. For example, the base flange is attached at least partially to the end side of the roll main body. A releasable connection of the base flange to the roll main body makes a replacement of the complete edge element possible in a simple way.
The invention also comprises a roll mill having a first milling roll and a second milling roll which are arranged opposite one another and which can be driven in opposite directions, at least one milling roll being configured as described in the preceding text. A milling gap is configured between the milling rolls, the edge element being configured in such a way that it extends over the milling gap and covers the opposite milling roll on the end side at least partially. It is likewise conceivable that each of the milling rolls has in each case precisely one edge element. Each of the milling rolls has, in particular, a first end region and a second end region, the first milling roll having, on its first end region, an edge element which covers the first end region of the second milling roll in the region of the milling gap on the end side. The second milling roll preferably has, on its second end region, an edge element which covers the second end region of the first milling roll in the region of the milling gap on the end side. In particular, the edge elements are arranged so as to lie diagonally opposite one another in relation to the end regions of the milling rolls. In a further embodiment, exclusively one milling roll has two edge elements which are attached to opposite roll ends of the milling rolls, the opposite milling roll not having any edge element. In each case one end-side gap is preferably configured between the edge elements and the end side of the respective opposite milling roll. An end-side gap prevents a collision of the edge element with the end region of the respective opposite milling roll in the case of skewed running of the milling rolls, the milling rolls which lie opposite one another not being arranged parallel to one another. In the case of a parallel arrangement of the opposite milling rolls with respect to one another, the end-side gap serves to decrease the wear of the edge elements.
The edge elements preferably cover the opposite milling rolls by approximately from 2 to 10%, in particular from 4 to 7%, preferably 5% of the roll diameter. The coverage is understood to mean that region of the opposite milling roll, along which the edge element extends in the radial direction. An excessively small coverage leads to an outflow of the material past the edge elements, an excessively large coverage leading to a collision in the case of skewed positioning of the milling rolls with respect to one another. A coverage of the edge elements of approximately from 2 to 10%, in particular from 4 to 7%, preferably 5% of the roll diameter affords an optimum coverage, a collision and an outflow of the material beyond the edge elements being avoided. The milling rolls of the roll mill are preferably of structurally identical configuration. This affords the advantage of an easy replacement capability of the milling rolls in the case of maintenance, and makes a time and cost saving possible.
The invention also comprises a method for setting an end-side gap of a roll mill with a first milling roll and a second milling roll which are arranged so as to lie opposite one another and which can be driven in opposite directions. A milling gap is configured between the milling rolls, each of the milling rolls having, on an end region of a respective roll end, an edge element which is configured in such a way that it extends over the milling gap and covers the opposite milling roll on the end side at least partially, with the result that an end-side gap is configured between the edge element and the end side of the respective opposite milling roll. The edge element has a base flange. The method for setting the end-side gap comprises the steps:
attaching a spacer element to the base flange, and attaching a plurality of wear protection elements to the spacer element.
The advantages which are described in relation to the milling roll apply accordingly in method terms to the method for setting an end-side gap. The described method preferably serves for setting the width of the end-side gap, the width of the end-side gap preferably being dependent on the thickness of the spacer element. The spacer element is attached, in particular, to that side face of the base flange which points axially inward in the direction of the end-side gap, with the result that the width of the end-side gap is decreased. Each edge element of the roll mill preferably has an identical spacer element, with the result that the end-side gaps of a milling roll preferably have the same width. It is likewise conceivable that a plurality of, for example two or three, spacer elements are attached next to one another in the axial direction to in each case one base flange.
In accordance with one embodiment, the spacer element and the wear protection elements are fastened releasably 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 attached to the spacer element in each case by means of releasable fastening means such as screws. For example, the plurality of spacer elements are screwed to one another and to the base flange.
An above-described edge element with a spacer element and a plurality of wear protection elements affords the advantage of a simple setting capability of the edge-side gap, with the result that, depending on the application, a spacer element with a corresponding thickness can be fastened to the base flange in a simple way and the desired end-side gap is therefore set.
In the following text, the invention is described in greater detail on the basis of a plurality of exemplary embodiments with reference to the appended figures, in which:
The milling rolls 12, 14 in each case have a first end region 24, 28 and a second end region 22, 26 which are arranged at opposite ends of the milling roll. The first end region 24 of the first milling roll 12 is arranged so as to lie opposite the first end region 28 of the second milling roll 14, the second end region 22 of the first milling roll 12 being arranged so as to lie opposite the second end region 26 of the second milling roll 14.
Furthermore, the roll mill 10 has a first edge element 18 and a second edge element 20, in each case one edge element 18, 20 being arranged on each milling roll 12, 14. The edge elements 18, 20 are arranged so as to lie diagonally opposite one another in relation to the end regions 22 to 28 of the milling rolls 12, 14. On its first end region 24, the first milling roll 12 has an edge element 18 which extends in the radial direction over the milling gap 16 and covers the end side of the second milling roll 14 on the first end region 28 partially. On its second end region 26, the second milling roll 14 has an edge element 20 which extends in the radial direction over the milling gap 16 and covers the end side of the first milling roll 12 on its second edge region 22 partially. The second edge element 20 is arranged on the diagonally opposite end region 26 of the second milling roll 14 in relation to the first edge element 18. The milling rolls 12, 14 are arranged offset in the axial direction, with the result that a first end-side gap 34 is configured between the first edge element 18 and the end side of the second milling roll 14 and a second end-side gap 36 is configured between the second edge element 20 and the end side of the first milling roll 12. The first and the second end-side gap 34, 36 extend in each case in the radial direction.
Each milling roll 12, 14 comprises a preferably cylindrical roll main body 11, 13 which has a milling face which is formed by way of the cylindrical surface of the roll main body. The edge elements 18, 20 comprise, for example, in each case one circumferential circular ring which is attached to the respective milling roll 12, 14 in a way which is not shown. For example, the edge elements 18, 20 are attached to the end side or on the outer circumference of the milling roll, in particular the respective roll main body. For example, a circumferential groove is arranged on the outer circumference of the respective milling roll 12, 14, in which groove in each case one edge element 18, 20 is arranged. The edge elements 18, 20 are configured from a wear-resistant material, such as, for example, steel, and have, for example, a thickness of from 10 mm to 100 mm and cover the opposite milling rolls 12, 14 by approximately from 2 to 10%, in particular from 4 to 7%, preferably 5% of the roll diameter.
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 are configured from a wear-resistant material, such as, for example, tungsten carbide or ceramic. The wear protection elements 42 are preferably attached next to one another to the spacer element 40, with the result that that surface of the spacer element 40 which points inward in the axial direction of the milling roll 12 is preferably covered completely 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 releasable connecting means, such as screws or bolts.
The milling roll 12 has by way of example an edge protection means 44 which preferably comprises a plurality of corner blocks which are attached to an end region of the milling roll, for example, in a circumferential groove. The edge protection means 44 preferably lies against the wear protection elements 42.
A spacer element 40 makes simple setting of the end-side gap 34, 36 of the roll mill 10 possible, in particular without an axial displacement of the milling rolls 12, 14 with respect to one another. In order to set the end-side gap 34, 36, a spacer element 40 with a corresponding thickness is attached to the base flange 38. Subsequently, for example, the wear protection elements 42 are fastened to the spacer element 40. In order to achieve a further increase or decrease of the end-side gap 34, 36, an axial displacement of at least one of the milling rolls 12, 14 relative to the other milling roll 12, 14 is possible.
Number | Date | Country | Kind |
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10 2019 209 511.9 | Jun 2019 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2020/067541 | 6/23/2020 | WO |