EP3990189B1 - Roller mill and method of operating a roller mill - Google Patents

Roller mill and method of operating a roller mill Download PDF

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Publication number
EP3990189B1
EP3990189B1 EP20735298.0A EP20735298A EP3990189B1 EP 3990189 B1 EP3990189 B1 EP 3990189B1 EP 20735298 A EP20735298 A EP 20735298A EP 3990189 B1 EP3990189 B1 EP 3990189B1
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EP
European Patent Office
Prior art keywords
roller
grinding
grinding roller
measuring device
roller mill
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP20735298.0A
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German (de)
French (fr)
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EP3990189A1 (en
Inventor
Frank Schroers
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FLSmidth AS
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FLSmidth AS
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Publication of EP3990189A1 publication Critical patent/EP3990189A1/en
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C4/00—Crushing or disintegrating by roller mills
    • B02C4/28—Details
    • B02C4/40—Detachers, e.g. scrapers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C25/00—Control arrangements specially adapted for crushing or disintegrating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C4/00—Crushing or disintegrating by roller mills
    • B02C4/02—Crushing or disintegrating by roller mills with two or more rollers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C4/00—Crushing or disintegrating by roller mills
    • B02C4/28—Details
    • B02C4/30—Shape or construction of rollers
    • B02C4/305—Wear resistant rollers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
    • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
    • B02C2210/00—Codes relating to different types of disintegrating devices
    • B02C2210/02—Features for generally used wear parts on beaters, knives, rollers, anvils, linings and the like

Definitions

  • the invention relates to a roller mill with edge elements for comminuting granular material and a method for operating a roller mill.
  • Roller mills are usually used to crush grist, such as limestone, clinker or similar rocks.
  • grist such as limestone, clinker or similar rocks.
  • edge elements 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.
  • a roller mill with edge elements is, for example, from DE 20 2014 006 837 U1 known.
  • An increased specific grinding pressure acts on the edge elements, which leads to a high load on the edge elements and thus often to wear or breakage of the edge elements.
  • Roller mills with scraper elements are in WO 2018/206200 A1 and US5054701A disclosed.
  • a roller mill for comminuting granular material comprises a first grinding roller and a second grinding roller, which are arranged opposite one another and can be driven in opposite directions, with a grinding gap being formed between the grinding rollers.
  • At least one of the grinding rollers has an edge element on an end region of a grinding 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 at the front.
  • a scraper element for removing material is arranged on the end region of the end of the grinding roller that is provided with an edge element.
  • the scraper element is used in particular for at least partially removing material that has accumulated on the end region of the grinding roller.
  • the material is scraped off by the scraper element during operation of the roller mill, with the grinding rollers rotating in opposite directions.
  • the scraper element is preferably arranged on the end area of the grinding roller in such a way that it does not touch the grinding roller.
  • the end area of the grinding roller comprises, for example, the end face of the grinding roller, the surface of the grinding roller adjoining it, and an area surrounding the surface of the grinding roller, in which material is deposited.
  • such an area has a height of more than or equal to 2 mm to 10 mm, in particular more than or equal to 4 mm to 8 mm, preferably 5 mm.
  • the edge element includes, in particular, an encircling circular ring, preferably a circular disc.
  • the edge element is attached to the end face of the respective grinding roller, for example screwed or welded.
  • 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.
  • the grinding rollers include, in particular, a roller base body, with the edge element being detachably connected to the roller base body of the respective 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 and preferably have wear protection.
  • the wear protection is arranged on the inner surface of the edge element pointing in the direction of the milling gap.
  • Such wear protection includes, for example, a wear-resistant coating, such as build-up welding, Wear protection elements or wear protection coatings.
  • the edge elements are preferably made of steel.
  • this wear protection layer is thicker on the end areas of the roll ends, which are provided with edge elements, than on the other areas of the grinding rolls. This leads to increased grinding pressure, which puts more stress on the edge elements and causes them to wear out or fail more often.
  • the material build-up on the edge elements at the ends of the grinding rollers is reliably prevented by means of the scraper elements. This minimizes the risk of increased wear and failure of the edge elements.
  • the roller mill according to the invention has a measuring device for determining the layer thickness of the material to be ground on at least one of the grinding rollers and/or for determining the load on the edge element. Furthermore, the roller mill has a control device which is connected to the measuring device and is designed to reduce or increase the distance between the stripper element and the grinding roller depending on the layer thickness and/or load determined.
  • the control device includes a computer, for example, and is preferably connected to the measuring device in such a way that the data determined by the measuring device, such as the load and/or the layer height of the material to be ground on the grinding roller, is transmitted to the control device.
  • the load includes, for example, the forces acting on the edge element or the relative expansion of the edge element.
  • the stripper element is preferably arranged at a distance from the edge element and/or the end region of the grinding roller.
  • the distance between the scraper element and the edge element and/or the end area of the grinding roller is preferably more than or equal to 2 mm -10 mm, in particular 4 mm to 8 mm, preferably 5 mm.
  • a distance between the scraper element and the edge element and/or the end area of the grinding roller prevents the scraper element from coming into contact with the grinding roller and thus reduces wear on the scraper element.
  • the scraper element is arranged in such a way that the distance between the scraper element and the edge element and/or between the scraper element and the end area of the grinding roller can be adjusted.
  • the thickness of the material layer at the end areas of the grinding rollers does not exceed a specific value of, for example, 2 to 10 mm, in particular 4 to 8 mm, preferably 5 mm.
  • An adjustable distance ensures that when the scraper element wears, the distance between the scraper element and the edge element and/or the end area of the grinding roller is kept constant.
  • the service life of the wiper element is extended and replacement is not necessary in the event of wear.
  • Each of the grinding rollers preferably has an edge element on an end region of a roller end, which is designed in such a way that it extends over the grinding gap and at least partially covers the opposite grinding roller at the front.
  • the edge elements are arranged diagonally opposite with respect to the end regions of the grinding rollers.
  • the wiper element extends in particular along an edge element.
  • the stripper element extends in the radial direction of the grinding roller, for example parallel or at an angle to the edge element. The distance between the edge element and the wiping element is preferably constant over the length of the wiping element.
  • the stripper element is attached to a holder, the holder being designed to be movable in the direction of the grinding roller.
  • the holder extends essentially in the radial direction of the grinding roller.
  • the holder includes a spindle or telescopic rod, which can each be driven, for example, by means of an electric motor or manually by means of a handwheel, so that the holder is moved in the direction of the grinding roller or away from the grinding roller.
  • the holder is preferably linearly movable.
  • the wiper element is preferably detachably attached to the holder, for example by means of screws.
  • the roller mill has a first measuring device for determining the layer height of ground material on the grinding roller and a second measuring device for determining the load on the edge element.
  • the first measuring device is preferably attached to a machine frame which is stationary relative to the rotating grinding rollers.
  • the first measuring device is arranged in such a way that it determines the layer height of the material to be ground on the grinding roller during the rotation of the grinding roller at its upper turning point.
  • the scraper elements are preferably arranged at a position in the direction of rotation of the grinding roller before the upper turning point.
  • the second measuring device is for example attached to the edge member.
  • the roller mill preferably has two of the first and second measuring devices, with a second measuring device being attached to each edge element and a first measuring device being attached to each end region of a grinding roller provided with an edge element.
  • the first and the second measuring device are preferably each connected to the control device for transmitting the determined measurement data. The majority of the measuring devices serve to reliably monitor each edge element of the roller mill.
  • the first measuring device is an optical measuring device, in particular a laser measuring device, infrared measuring device or an electromagnetic measuring device, such as a radar measuring device (microwaves in the range of 1-300 GHz).
  • the measuring method is to be understood as meaning both the optical measuring method, the laser measuring method and the radar measuring method.
  • the measuring device is installed, for example, at a previously known distance from the surface of the grinding roller, preferably above the grinding roller.
  • the layer height is preferably determined in a lateral edge area of the grinding roller using an optical measurement method or radar measurement.
  • a surface area is detected, in particular by means of radar measurement, which extends, for example, over the entire width and length of the grinding roller or only over part of the grinding roller, for example the end area.
  • radar measurement the surface of the material to be ground on the grinding roller is recorded over an area and, for example, the highest value of the layer height in this area is determined.
  • a plurality of measuring devices are provided, which are mounted above the surface of the grinding roller, for example evenly spaced from one another, around the circumference, in order to preferably detect a surface area of the grinding roller and to determine the layer height in this area, preferably over an area.
  • the height of the ground material is determined at a large number of individual measuring points that are spaced apart from one another, from which a 2D image of the ground material surface is determined, for example by means of interpolation.
  • the measuring methods for determining the layer height are a simple and reliable way of determining the layer height when the roller mill is in operation.
  • the second measuring device comprises a strain gauge.
  • the second measuring device comprises a plurality of strain gauges, preferably 2, 4, 6, 8 or 10 strain gauges.
  • the strain gauges are circumferentially uniform, for example, on the edge element mounted spaced apart.
  • a strain gauge is attached to a screw, by means of which the edge element or a segment of the edge element is connected to the roller body. The strain gauge determines the relative expansion or compression of the area to which it is attached, from which the stresses occurring thereon, in particular the forces acting on the edge elements and/or the screws, are determined.
  • the control device is designed in such a way that it reduces the distance between the scraper element and the grinding roller when the layer height exceeds a predetermined limit value.
  • the limit value is, for example, 2 mm to 10 mm, in particular 4 mm to 8 mm, preferably 5 mm.
  • the distance is preferably increased if the layer height falls below the previously determined limit value. If the layer height exceeds the predetermined limit value, it can be concluded that the wiper element is worn.
  • the limit value is preferably stored in the control device. By reducing the distance, the worn area of the wiper element is compensated. Likewise, if the distance is increased, excessive wear of the wiper element is counteracted.
  • the distance is to be understood in particular as the distance between the scraper element and the surface of the roller base body, in particular the grinding surface of the grinding roller.
  • control device is designed in such a way that it reduces the distance between the scraper element and the grinding roller when the load, in particular the elongation of the edge element, exceeds a predetermined limit value.
  • the distance is preferably increased by means of the control device when the load, in particular the relative expansion of the edge element, falls below the predetermined limit value.
  • the measuring device is arranged in the direction of rotation of the grinding roller between the scraper and the grinding gap. This monitors the function of the scraper, whereby the layer thickness is determined at a point where no other material is pressed against the roller.
  • the stripper element is preferably arranged in such a way that material accumulated on the edge element and/or on the end region of the grinding roller is removed during operation of the roller mill removed.
  • the scraper element is arranged to be stationary or movable relative to the rotatable grinding rollers, so that the grinding rollers rotate relative to the scraper element.
  • the roller mill has a stationary machine frame and the scraper element is attached to the machine frame.
  • the machine frame includes, for example, several frame elements that are connected to bearing blocks of the grinding rollers, so that the grinding force acting on the grinding rollers is transmitted to the machine frame.
  • a machine frame of a roller mill comprises a frame element which extends essentially in the axial direction of the grinding rollers and to which the scraper element is preferably attached.
  • the scraper element extends from the machine frame in the direction of the grinding roller, in particular in the end area of the grinding roller.
  • the roller mill has at least two scraper elements which are arranged at end regions of different roller ends of the grinding roller.
  • the stripper elements are preferably arranged on opposite end areas of a grinding roller.
  • Each scraper element is preferably attached to a respective holder which is attached such that it can be moved in the direction of the grinding roller.
  • the scraper element has a scraper plate which is formed from a wear-resistant material such as tungsten carbide.
  • the stripper plate is arranged on the end of the stripper element facing the grinding roller and is in contact with the material to be stripped during operation of the roller mill. The stripper plate is therefore exposed to a high level of wear, with wear-resistant material extending the service life of the stripper plate.
  • the wiper element has an arm on which the wiper plate is detachably fastened.
  • the stripper plate is clamped or screwed to the arm.
  • the stripper plate preferably protrudes beyond the arm in the direction of the grinding roller.
  • the material is preferably removed at two end regions of the grinding roller, each provided with an edge element. According to a further embodiment, the distance is reduced if the ascertained layer height exceeds a predetermined limit value. According to a further embodiment, the distance is reduced when the load exceeds a predetermined limit value.
  • FIG. 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 almost parallel to one another, so that the grinding gap 16 extending between the grinding rollers 12, 14 has an almost 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, the first grinding roller 12 being longer than the second grinding roller 14 can be.
  • 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 first grinding roller 12 has, for example, 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 at the second end area 24 attached to 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 over the second end region 28 .
  • the edge elements 18, 20 preferably each comprise a circumferential circular ring, which can also consist of segments, for example, and is attached to the respective grinding roller 12, 14 in a manner that is not shown.
  • 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.
  • 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 wear-resistant coating or a plurality of, for example, plate-shaped anti-wear elements, particularly on the inside facing the grinding gap 16.
  • the edge elements 18, 20 have a thickness of 10 mm to 100 mm, for example, and cover the opposite grinding rollers 12, 14 by about 2-20%, in particular 4-10%, preferably 3-6% of the roller diameter.
  • FIG. 2 shows a further embodiment of a grinding roller with edge elements 18, 20, wherein the grinding roller essentially corresponds to that in 1 shown grinding roller corresponds with the difference that in the embodiment of 2 each of the grinding rollers 12, 14 has a respective edge element 18, 20.
  • the first and the second grinding roller 12, 14 have the same diameter and the same length and are of essentially identical construction.
  • the edge elements 18, 20 are arranged diagonally opposite one another in relation to the end regions 22-28 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 element 20 is arranged on the diagonally opposite end region 26 of the second grinding roller 14 with respect to the first edge element 18 .
  • the grinding rollers 12, 14 are arranged offset in the axial direction, so that between the first edge element 18 and the end face of the second Grinding roller 14 is a first end-side gap 34 is formed and between the second edge element 20 and the end face of the first grinding roller 12 a second end-side gap 36 is formed.
  • the first and the second end gap 34, 36 each extend in the radial direction.
  • the edge elements 18, 20 comprise, for example, a plurality of segments in the shape of a part circle, each of which is screwed to the end face of a respective end region of the grinding roller 12. Each segment is fastened to the face of the grinding roller 12 with a plurality of screws or bolts.
  • FIG. 12 also shows two scraper elements 42, 44 which are each attached to a holder 38, 40 and each extend in the direction of a respective end region of the grinding roller 12.
  • the holders 38, 40 are preferably each attached to a machine frame, not shown, with the grinding rollers 12, 14 in particular being mounted on the machine frame.
  • the scraper elements 42, 44 are arranged at a distance from the grinding roller 12 and the edge element 18, 20 of the grinding roller 12, so that the scraper does not touch the grinding roller 12 and the edge elements 18, 20.
  • the first scraper element 42 is attached in such a way that it faces the first end region 22 of the grinding roller 12, the first scraper element 42 extending in the radial direction of the grinding roller 12 along the first edge element 18 and being aligned essentially parallel thereto.
  • the second stripper element 44 is arranged in a corresponding manner on the second end area 24 and the second edge element 20 of the grinding roller 12 .
  • the scraper elements 42, 44 each extend along the surface of the edge elements 18, 20 pointing inwards in the axial direction of the grinding roller 12.
  • the scraper elements 42, 44 are, for example, of identical design.
  • the holders 38, 40 are preferably designed in such a way that they can be moved in and/or counter to the direction of the grinding roller 12, so that when the holders 38, 40 move in or counter to the direction of the grinding roller, the distance between the grinding roller, in particular the surface of the grinding roller 12, 14 and the scraper element 42, 44 is reduced or increased.
  • the holders 38, 40 are preferably linearly movable in the direction of the grinding roller 12, 14 or away from the grinding roller 12, 14.
  • the brackets 38, 40 are for example, a telescopic rod or a spindle, which can be driven preferably by means of an electric motor, not shown, or manually by means of a handwheel.
  • FIG. 1 also shows a first measuring device 62 for determining the layer thickness of the material to be ground adhering to the surface of the grinding roller.
  • the first measuring device 62 is, for example, an optical measuring device, the layer thickness being determined, for example, by means of a laser.
  • the first measuring device 62 is preferably arranged in such a way that the layer thickness of the material to be ground is determined at an end region of the grinding roller 12, 14, in particular in the vicinity of or on one of the edge elements 18, 20.
  • the first measuring device 62 is preferably mounted behind the scraper element 42, 44 in the direction of rotation of the grinding roller 12, so that the layer thickness is determined circumferentially between the scraper element 42, 44 and the grinding gap 16 during operation of the roller mill 10.
  • the direction of rotation of the grinding roller 12 is in 3 shown with an arrow.
  • the first measuring device 62 is attached, for example, to the machine frame described above and is arranged in a stationary manner relative to the rotatable grinding rollers 12 , 14 .
  • the roller mill 10 also has a second measuring device 64 which is attached to an edge element 18, 20 and is designed in such a way that it determines the load acting on the respective edge element 18, 20. Load is to be understood, for example, as the force acting on the edge element 18, 20 and/or the stresses occurring in the respective edge element 18, 20.
  • the second measuring device 64 is, for example, one or a plurality of strain gauges.
  • the strain gauge is attached to the edge element 18, 20 in order to determine the stresses occurring in the edge element, in particular the forces acting on the edge element. It is also conceivable to attach a plurality of strain gauges to different positions on the edge element 18, 20.
  • one or a plurality of screws for fastening the edge element 18, 20 to the roller body of the grinding roller 12, 14 are each provided with a strain gauge.
  • the second measuring device 64 is preferably arranged behind the stripper element 42, 44 and in front of the grinding gap 16 in the direction of rotation of the grinding roller 12, 14.
  • the roller mill 10 also includes a control device 66 for adjusting the distance between the scraper element 42, 44 and the surface of the grinding roller 12, 14.
  • the control device 66 communicates with the first and/or the second measuring device 62, 64 in such a way that the data determined by means of the respective measuring device 62, 64 is transmitted to the control device 66.
  • the control device 66 is also connected to the holder 38, 40, preferably to both holders 38, 40 of the wiper elements 42, 44.
  • the control device 66 is connected to an electric motor, which moves the holders 38, 40 of the scraper elements 42, 44, preferably in the direction of the grinding roller 12, 14 or away from the grinding roller 12, 14.
  • the control device 66 is connected to the holders 38, 40 and/or the electric motor in such a way that it can move the holders in the direction of the grinding roller 12, 14 or away from the grinding roller 12, 14 by means of a control signal.
  • FIG. 1 only shows the arrangement of the stripping elements 42, 44 on a roller mill according to FIG Fig.1 .
  • the roller mill 10 shown also has, for example, two stripper elements 42, 44.
  • Each grinding roller 12, 14 of the in 2 Roller mill 10 shown has a scraper element 42, 44, which is attached, for example, to a roller frame and corresponding to the embodiment of FIG 3 in the direction of a respective end region of the grinding roller 12, 14 having an edge element 18, 20.
  • a first measuring device 62 is attached to each end region of the grinding roller and a second measuring device 64 is attached to each edge element 18 , 20 .
  • all measuring devices 62, 64 are connected to a control device 66.
  • the control device 66 compares, for example, the measured values transmitted by the first and/or the second measuring device 62, 64 with a corresponding limit value determined in advance. For example, the control device 66 compares the value of the layer height of the material to be ground on the grinding roller 12, 14 transmitted by means of the first measuring device 62 with a previously determined limit value of the layer height, which is stored in the control device 66.
  • the control device 66 is preferably designed and set up in such a way that it reduces the distance between the respective stripper element 42, 44 and the surface of the respective grinding roller 12, 14 when the determined layer height exceeds the predetermined limit value.
  • the control device 66 transmits, for example, a control signal to the electric motor or to the holders 38, 40, so that the holders 38, 40 and the stripper elements 42, 44 fixed thereto can be moved in the direction of the grinding roller 12, 14, in particular in the direction of the Grinding roller surface are moved and the distance between the scraper elements 42, 44 and the surface of the grinding roller 12, 14 is reduced.
  • the predetermined limit value of the layer height is, for example, 2 mm to 10 mm, in particular 4 mm to 8 mm, preferably 5 mm.
  • the control device 66 is preferably designed and set up such that it increases the distance between the respective stripper element 42, 44 and the surface of the respective grinding roller 12, 14 when the determined layer height falls below the predetermined limit value.
  • An increased layer thickness of ground material on the grinding roller 12, 14 indicates wear of the scraper element 42, 44, with a reduction in the distance between the scraper element 42, 44 and the surface of the grinding roller corresponding to a wear adjustment of the scraper element 42, 44, so that the wear of the Stripper element 42, 44 is compensated.
  • the control device 66 compares the load value transmitted by the second measuring device 64, preferably the elongation of the edge elements 18, 20 and/or the forces acting on the edge elements 18, 20 and/or the screws, with a previously determined limit value of the respective load , preferably the elongation that is stored in the control device 66.
  • the control device 66 is preferably designed and set up in such a way that it reduces the distance between the respective stripper element 42, 44 and the surface of the respective grinding roller 12, 14 when the determined load, in particular the elongation, exceeds the predetermined limit value. This is preferably done as described above.
  • the control device 66 is preferably designed and set up in such a way that it reduces the distance between the respective stripper element 42, 44 and the surface of the respective grinding roller 12, 14 when the determined load, in particular the elongation, falls below the predetermined limit value.
  • FIG. 4 12 shows an enlarged view of an exemplary wiper element 42,44.
  • the wiper element 42,44 has a mounting plate 46 which is attached to the bracket 38,40 in the assembled position of the wiper element 42,44.
  • the mounting plate has a plurality of mounting holes 48, which are used to attach the wiper element 42, 44 to the holder 38, 40, for example by means of screws.
  • an arm 50 is attached, for example, at an angle of about 30-60 °, in particular about 45 ° to the mounting plate 46 in the direction of not illustrated grinding roller 12, 14 extends.
  • Attached to the arm 50 is a stripper plate 52 which is secured to the arm 50 by means of two screws 54 and a clamping plate 56 .
  • the stripper plate extends parallel to the arm 50 beyond the end of the arm facing away from the fastening plate 46, so that the stripper plate 52 on the arm 50 protrudes in the radial direction of the grinding roller 12, 14.
  • the stripper plate 52 is clamped between the clamping plate 56 and the arm 50 so that it can be easily replaced if it becomes worn.
  • the stripper plate 58 is arranged in a clamping receptacle 58 which is arranged between the clamping plate 56 and the arm 50 and is clamped by means of the clamping plate 56 and the screws 54 .
  • the front edge of the stripper plate 52 extends in the embodiment of FIG 4 at an angle to the surface of the respective grinding roller 12, 14, so that the distance between the stripper plate 52 and the surface of the grinding roller 12, 14 is smaller in the direction of the grinding roller end.
  • the angle between the stripper plate 52 and the surface of the grinding roller 12, 14 is 45° - 135°, for example. It is also conceivable that the front edge of the stripper plate 52 extends essentially parallel to the surface of the respective grinding roller 12, 14, in particular in the axial direction direction of the grinding roller.
  • the side surface of the stripper plate 52 and the side surface of the arm 50 extend along the respective edge element 18, 20. In particular, there is a gap of 2mm to 10mm, preferably 4mm to 8mm, between the stripper element 42, 44 and the surface of the grinding roller 12, 14. formed in particular 5mm.
  • the mounting plate 46, arm, clamp seat 58 and clamp plate 56 are formed of steel, for example.
  • the stripper plate is formed, for example, from a highly wear-resistant material such as tungsten carbide.
  • figure 5 shows a rear view of the wiper element 42, 44 of 4 .
  • the arm 50 has a substantially U-shaped profile, with the clamping plate 56 and the clamping receptacle 58 being attached to the arm 50 by means of screws 54 and nuts.
  • the edge elements 18, 20 prevent material from escaping laterally from the grinding gap 16.
  • Autogenous wear protection is built up on the surface of the grinding rollers 12, 14 as a result of the deposition of material.
  • the scraper elements 42, 44 strip off material deposited on the end regions of the grinding roller 12, 14 and thus ensure that the autogenous wear protection layer also in the end areas of the grinding rollers 12, 14, to which the edge elements are attached, does not rise above a specific thickness, so that the edge elements are reliably protected against high pressure from deposited material.

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  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Crushing And Grinding (AREA)

Description

Die Erfindung betrifft eine Walzenmühle mit Randelementen zur Zerkleinerung von körnigem Material, sowie ein Verfahren zum Betreiben einer Walzenmühle.The invention relates to a roller mill with edge elements for comminuting granular material and a method for operating a roller mill.

Walzenmühlen werden üblicherweise zur Zerkleinerung von Mahlgut, wie beispielsweise Kalkstein, Klinker oder ähnliche Gesteine eingesetzt. Bei der Zerkleinerung von Mahlgut in einer Walzenmühle kommt es vor, dass Mahlgut seitlich aus dem Mahlspalt austritt, ohne den Mahlspalt vollständig oder überhaupt passiert zu haben. Dieses führt zur Senkung der Durchsatzleistung der Maschine und zur Erhöhung der Mahlkreisumläufe, was mit einem enormen Energieaufwand verbunden ist.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.

Zur kontrollierten Beeinflussung des seitlichen Abfließens von Mahlgut aus einem zwischen den Mahlwalzen einer Walzenmühle ausgebildeten Mahlspalt ist es bekannt, Randelemente an einer der Mahlwalze anzuordnen. Eine solche Walzenmühle mit Randelementen ist beispielsweise aus der DE 20 2014 006 837 U1 bekannt. Auf die Randelemente wirkt ein erhöhter spezifischer Mahldruck, der zu einer starken Belastung der Randelemente und somit häufig zum Verschleiß oder Bruch der Randelemente führt. Walzenmühlen mit Abstreiferelementen sind in WO 2018/206200 A1 und US 5054701 A offenbart.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. An increased specific grinding pressure acts on the edge elements, which leads to a high load on the edge elements and thus often to wear or breakage of the edge elements. Roller mills with scraper elements are in WO 2018/206200 A1 and US5054701A disclosed.

Davon ausgehend ist es Aufgabe der vorliegenden Erfindung, eine Walzenmühle mit Randelementen bereitzustellen, wobei die Randelemente geringeren Belastungen und Verschleiß ausgesetzt sind.Proceeding from this, it is the object of the present invention to provide a roller mill with edge elements, the edge elements being subjected to lower loads and wear.

Diese Aufgabe wird erfindungsgemäß durch eine Vorrichtung mit den Merkmalen des unabhängigen Vorrichtungsanspruchs 1, sowie durch ein Verfahren mit den Merkmalen des unabhängigen Verfahrensanspruchs 12 gelöst. Vorteilhafte Weiterbildungen ergeben sich aus den abhängigen Ansprüchen.According to the invention, this object is achieved by a device having the features of independent device claim 1 and by a method having the features of independent method claim 12 . Advantageous developments result from the dependent claims.

Eine Walzenmühle zum Zerkleinern von körnigem Material umfasst nach einem ersten Aspekt eine erste Mahlwalze und eine zweite Mahlwalze, die gegenüberliegend angeordnet und gegenläufig antreibbar sind, wobei zwischen den Mahlwalzen ein Mahlspalt ausgebildet ist. Zumindest eine der Mahlwalzen weist an einem Endbereich eines Mahlwalzenendes ein Randelement auf, das derart ausgebildet ist, dass es sich über den Mahlspalt erstreckt und die gegenüberliegende Mahlwalze stirnseitig zumindest teilweise überdeckt.According to a first aspect, a roller mill for comminuting granular material comprises a first grinding roller and a second grinding roller, which are arranged opposite one another and can be driven in opposite directions, with a grinding gap being formed between the grinding rollers. At least one of the grinding rollers has an edge element on an end region of a grinding 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 at the front.

An dem mit einem Randelement versehenen Endbereich des Mahlwalzenendes ist ein Abstreiferelement zum Entfernen von Material angeordnet. Das Abstreiferelement dient insbesondere zum zumindest teilweisen Entfernen von an dem Endbereich der Mahlwalze angelagertem Material. Das Material wird im Betrieb der Walzenmühle, wobei die Mahlwalzen gegenläufig rotieren, von dem Abstreiferelement abgestriffen. Das Abstreiferelement ist vorzugsweise derart an dem Endbereich der Mahlwalze angeordnet, dass es die Mahlwalze nicht berührt. Der Endbereich der Mahlwalze umfasst beispielsweise die Stirnseite der Mahlwalze, die daran angrenzende Mahlwalzenoberfläche, sowie einen die Mahlwalzenoberfläche umgebenden Bereich, in dem sich Material ablagert. Beispielsweise weist ein solcher Bereich eine Höhe von mehr als oder gleich 2mm bis 10mm, insbesondere mehr als oder gleich 4mm bis 8mm, vorzugsweise 5mm auf.A scraper element for removing material is arranged on the end region of the end of the grinding roller that is provided with an edge element. The scraper element is used in particular for at least partially removing material that has accumulated on the end region of the grinding roller. The material is scraped off by the scraper element during operation of the roller mill, with the grinding rollers rotating in opposite directions. The scraper element is preferably arranged on the end area of the grinding roller in such a way that it does not touch the grinding roller. The end area of the grinding roller comprises, for example, the end face of the grinding roller, the surface of the grinding roller adjoining it, and an area surrounding the surface of the grinding roller, in which material is deposited. For example, such an area has a height of more than or equal to 2 mm to 10 mm, in particular more than or equal to 4 mm to 8 mm, preferably 5 mm.

Das Randelement umfasst insbesondere einen umlaufenden Kreisring, vorzugsweise eine Kreisscheibe. Insbesondere ist das Randelement an der Stirnseite der jeweiligen Mahlwalze angebracht, beispielsweise verschraubt oder verschweißt.The edge element includes, in particular, an encircling circular ring, preferably a circular disc. In particular, the edge element is attached to the end face of the respective grinding roller, for example screwed or welded.

Zwischen den Randelementen und der Stirnseite der jeweils gegenüberliegenden Mahlwalze ist vorzugsweise jeweils ein stirnseitiger Spalt ausgebildet. Ein stirnseitiger Spalt verhindert eine Kollision des Randelements mit dem Endbereich der jeweils gegenüberliegenden Mahlwalze in dem Fall eines Schieflaufs der Mahlwalzen, wobei die gegenüberliegenden Mahlwalzen nicht parallel zueinander angeordnet sind.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.

Die Mahlwalzen umfassen insbesondere einen Walzengrundkörper, wobei das Randelement lösbar mit dem Walzengrundkörper der jeweiligen Mahlwalze verbunden ist. Die Mahlwalze umfasst vorzugsweise eine Antriebswelle zum Antrieb der Mahlwalze, auf welcher der Walzengrundkörper angeordnet ist. Eine lösbare Anordnung der Randelemente auf dem Walzengrundkörper bietet den Vorteil eines schnellen und einfachen Austauschs der Randelemente im Verschleißfall. Die Randelemente werden beispielsweise auf den Walzengrundkörper geklebt, gelötet, geschweißt oder geschraubt und weisen vorzugsweise einen Verschleißschutz auf. Insbesondere ist der Verschleißschutz auf der in Richtung des Mahlspalts weisenden Innenfläche des Randelements angeordnet. Ein solcher Verschleißschutz umfasst beispielsweise eine verschleißfeste Beschichtung, wie Auftragsschweißung, Verschleißschutzelemente oder Verschleißschutzbeschichtungen. Vorzugsweise sind die Randelemente aus Stahl ausgebildet.The grinding rollers include, in particular, a roller base body, with the edge element being detachably connected to the roller base body of the respective 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 and preferably have wear protection. In particular, the wear protection is arranged on the inner surface of the edge element pointing in the direction of the milling gap. Such wear protection includes, for example, a wear-resistant coating, such as build-up welding, Wear protection elements or wear protection coatings. The edge elements are preferably made of steel.

Im Betrieb der Walzenmühle bildet sich üblicherweise eine Materialschicht auf der Oberfläche der Mahlwalzen, die einen autogegen Verschleißschutz der Walzenoberfläche bewirkt. Gemäß einer Erkenntnis der Erfinder ist diese Verschleißschutzschicht an den Endbereichen der Walzenenden, die mit Randelementen versehen sind, dicker als an den übrigen Bereichen der Mahlwalzen. Dies führt zu einem erhöhten Mahldruck, durch welchen die Randelemente stärker belastet werden und häufiger verschleißen oder versagen. Mittels der Abstreiferelemente wird der Materialaufbau an den Mahlwalzenenden an den Randelementen zuverlässig verhindert. Dadurch wird die Gefahr eines erhöhten Verschleißes und eines Versagens der Randelemente minimiert.When the roller mill is in operation, a layer of material usually forms on the surface of the grinding rollers, which protects the roller surface against wear and tear. According to one finding of the inventors, this wear protection layer is thicker on the end areas of the roll ends, which are provided with edge elements, than on the other areas of the grinding rolls. This leads to increased grinding pressure, which puts more stress on the edge elements and causes them to wear out or fail more often. The material build-up on the edge elements at the ends of the grinding rollers is reliably prevented by means of the scraper elements. This minimizes the risk of increased wear and failure of the edge elements.

Die erfindungsgemäße Walzenmühle weist eine Messeinrichtung zum Ermitteln der Schichtdicke an Mahlgut auf zumindest einer der Mahlwalzen und/oder zum Ermitteln der Belastung des Randelements auf. Des Weiteren weist die Walzenmühle eine Steuerungseinrichtung auf, die mit der Messeinrichtung verbunden und dazu ausgebildet ist, den Abstand des Abstreiferelements zu der Mahlwalze in Abhängigkeit der ermittelten Schichtdicke und/oder Belastung zu verringern oder zu erhöhen. Die Steuerungseinrichtung umfasst beispielsweise einen Computer und ist vorzugsweise derart mit der Messeinrichtung verbunden, dass die mittels der Messeinrichtung ermittelten Daten, wie die Belastung und/ oder die Schichthöhe des Mahlguts auf der Mahlwalze, an die Steuerungseinrichtung übermittelt werden. Die Belastung umfasst beispielsweise die auf das Randelement wirkenden Kräfte oder die relative Dehnung des Randelements.The roller mill according to the invention has a measuring device for determining the layer thickness of the material to be ground on at least one of the grinding rollers and/or for determining the load on the edge element. Furthermore, the roller mill has a control device which is connected to the measuring device and is designed to reduce or increase the distance between the stripper element and the grinding roller depending on the layer thickness and/or load determined. The control device includes a computer, for example, and is preferably connected to the measuring device in such a way that the data determined by the measuring device, such as the load and/or the layer height of the material to be ground on the grinding roller, is transmitted to the control device. The load includes, for example, the forces acting on the edge element or the relative expansion of the edge element.

Das Abstreiferelement ist vorzugsweise zu dem Randelement und/ oder dem Endbereich der Mahlwalze beabstandet angeordnet. Vorzugsweise weist der Abstand zwischen dem Abstreiferelement und dem Randelement und/ oder dem Endbereich der Mahlwalze mehr als oder gleich 2mm -10mm, insbesondere 4mm bis 8mm, vorzugsweise 5mm auf. Ein Abstand zwischen dem Abstreiferelement und dem Randelement und/ oder dem Endbereich der Mahlwalze verhindert einen Kontakt des Abstreiferelements mit der Mahlwalze und vermindert somit der Verschleiß des Abstreiferelements.The stripper element is preferably arranged at a distance from the edge element and/or the end region of the grinding roller. The distance between the scraper element and the edge element and/or the end area of the grinding roller is preferably more than or equal to 2 mm -10 mm, in particular 4 mm to 8 mm, preferably 5 mm. A distance between the scraper element and the edge element and/or the end area of the grinding roller prevents the scraper element from coming into contact with the grinding roller and thus reduces wear on the scraper element.

Das Abstreiferelement ist derart angeordnet, dass der Abstand zwischen dem Abstreiferelement und dem Randelement und/ oder zwischen dem Abstreiferelement und dem Endbereich der Mahlwalze einstellbar ist. Insbesondere soll die Dicke der Materialschicht an den Endbereichen der Mahlwalzen einen bestimmten Wert von beispielsweise 2 bis 10mm, insbesondere 4 bis 8mm, vorzugsweise 5mm nicht überschreiten. Ein einstellbarer Abstand stellt sicher, dass bei einem Verschleiß des Abstreiferelements der Abstand zwischen dem Abstreiferelement und dem Randelement und/ oder dem Endbereich der Mahlwalze konstant gehalten wird. Zusätzlich wird die Lebensdauer des Abstreiferelements verlängert und ein Austausch ist im Verschleißfall nicht notwendig.The scraper element is arranged in such a way that the distance between the scraper element and the edge element and/or between the scraper element and the end area of the grinding roller can be adjusted. In particular, the thickness of the material layer at the end areas of the grinding rollers does not exceed a specific value of, for example, 2 to 10 mm, in particular 4 to 8 mm, preferably 5 mm. An adjustable distance ensures that when the scraper element wears, the distance between the scraper element and the edge element and/or the end area of the grinding roller is kept constant. In addition, the service life of the wiper element is extended and replacement is not necessary in the event of wear.

Jede der Mahlwalzen weist vorzugsweise an einem Endbereich eines Walzenendes jeweils ein Randelement auf, das derart ausgebildet ist, dass es sich über den Mahlspalt erstreckt und die gegenüberliegende Mahlwalze stirnseitig zumindest teilweise überdeckt. Insbesondere sind die Randelemente mit Bezug auf die Endbereiche der Mahlwalzen diagonal gegenüberliegend angeordnet. Das Abstreiferelement erstreckt sich insbesondere entlang eines Randelements. Insbesondere erstreckt sich das Abstreiferelement in radialer Richtung der Mahlwalze, beispielsweise parallel oder schräg zu dem Randelement. Der Abstand zwischen dem Randelement und dem Abtreifelement ist vorzugweise über die Länge des Abstreiferelements konstant.Each of the grinding rollers preferably has an edge element on an end region of a roller end, which is designed in such a way that it extends over the grinding gap and at least partially covers the opposite grinding roller at the front. In particular, the edge elements are arranged diagonally opposite with respect to the end regions of the grinding rollers. The wiper element extends in particular along an edge element. In particular, the stripper element extends in the radial direction of the grinding roller, for example parallel or at an angle to the edge element. The distance between the edge element and the wiping element is preferably constant over the length of the wiping element.

Gemäß einer ersten Ausführungsform ist das Abstreiferelement an einer Halterung angebracht, wobei die Halterung in Richtung der Mahlwalze bewegbar ausgebildet ist. Beispielsweise erstreckt sich die Halterung im Wesentlichen in radialer Richtung der Mahlwalze. Vorzugsweise umfasst die Halterung eine Spindel oder Teleskopstange, wobei diese jeweils beispielsweise mittels eines Elektromotors oder manuell mittels eines Handrades antreibbar sind, sodass die Halterung in Richtung der Mahlwalze oder von der Mahlwalze wegbewegt wird. Die Halterung ist vorzugsweise linear bewegbar. Das Abstreiferelement ist vorzugsweise lösbar, beispielsweise mittels Schrauben, an der Halterung angebracht.According to a first embodiment, the stripper element is attached to a holder, the holder being designed to be movable in the direction of the grinding roller. For example, the holder extends essentially in the radial direction of the grinding roller. Preferably, the holder includes a spindle or telescopic rod, which can each be driven, for example, by means of an electric motor or manually by means of a handwheel, so that the holder is moved in the direction of the grinding roller or away from the grinding roller. The holder is preferably linearly movable. The wiper element is preferably detachably attached to the holder, for example by means of screws.

Gemäß einer weiteren Ausführungsform weist die Walzenmühle eine erste Messeinrichtung zum Ermitteln der Schichthöhe an Mahlgut auf der Mahlwalze und eine zweite Messeinrichtung zum Ermitteln der Belastung des Randelements auf. Vorzugsweise ist die erste Messeinrichtung an einem relativ zu den rotierenden Mahlwalzen stationären Maschinenrahmen angebracht. Insbesondere ist die erste Messeinrichtung derart angeordnet, dass sie die Schichthöhe des Mahlguts auf der Mahlwalze während der Rotation der Mahlwalze an dessen oberen Wendepunkt ermittelt. Die Abstreiferelemente sind vorzugsweise an einer Position in Rotationsrichtung der Mahlwalze vor dem oberen Wendepunkt angeordnet. Die zweite Messeinrichtung ist beispielsweise an dem Randelement angebracht. Vorzugsweise weist die Walzenmühle jeweils zwei der ersten und der zweiten Messeinrichtung auf, wobei an jedem Randelement eine zweite Messeinrichtung und an jedem mit einem Randelement versehenen Endbereich einer Mahlwalze eine erste Messeinrichtung angebracht ist. Die erste und die zweite Messeinrichtung sind vorzugsweise jeweils mit der Steuerungseinrichtung zur Übermittlung der ermittelten Messdaten verbunden. Die Mehrzahl der Messeinrichtungen dient der zuverlässigen Überwachung jedes Randelements der Walzenmühle.According to a further embodiment, the roller mill has a first measuring device for determining the layer height of ground material on the grinding roller and a second measuring device for determining the load on the edge element. The first measuring device is preferably attached to a machine frame which is stationary relative to the rotating grinding rollers. In particular, the first measuring device is arranged in such a way that it determines the layer height of the material to be ground on the grinding roller during the rotation of the grinding roller at its upper turning point. The scraper elements are preferably arranged at a position in the direction of rotation of the grinding roller before the upper turning point. The second measuring device is for example attached to the edge member. The roller mill preferably has two of the first and second measuring devices, with a second measuring device being attached to each edge element and a first measuring device being attached to each end region of a grinding roller provided with an edge element. The first and the second measuring device are preferably each connected to the control device for transmitting the determined measurement data. The majority of the measuring devices serve to reliably monitor each edge element of the roller mill.

Gemäß einer weiteren Ausführungsform ist die erste Messeinrichtung eine optische Messeinrichtung, insbesondere eine Lasermesseinrichtung, Infrarotmesseinrichtung oder eine elektromagnetische Messeinrichtung, wie eine Radarmesseinrichtung (Mikrowellen im Bereich von 1-300 GHz). Im Folgenden ist unter dem Messverfahren sowohl das optische Messverfahren, das Lasermessverfahren als auch das Radarmessverfahren zu verstehen. Bei der Radarmessung wird die Messeinrichtung beispielsweise in einem vorbekannten Abstand zu der Oberfläche der Mahlwalze vorzugsweise oberhalb der Mahlwalze angebracht. Vorzugsweise wird die Schichthöhe in einem seitlichen Randbereich der Mahlwalze mittels einer optischen Messmethode oder der Radarmessung ermittelt. Es ist ebenfalls denkbar, dass insbesondere mittels Radarmessung ein Oberflächenbereich erfasst wird, der sich beispielsweise über die gesamte Breite und Länge Mahlwalze oder nur über einen Teil der Mahlwalze, beispielsweise den Endbereich, erstreckt. Bei einer solchen Radarmessung wird die Oberfläche des Mahlguts auf der Mahlwalze flächig erfasst und beispielsweise der höchste Wert der Schichthöhe in dieser Fläche ermittelt. Beispielsweise sind eine Mehrzahl von Messeinrichtungen vorgesehen, die oberhalb der Oberfläche der Mahlwalze, beispielsweise gleichmäßig zueinander beabstandet, über den Umfang abgebracht sind, um vorzugsweise einen Oberflächenbereich der Mahlwalze zu erfassen und die Schichthöhe in diesem Bereich vorzugsweise flächig zu ermitteln. Beispielsweise wird die Höhe des Mahlguts an einer Vielzahl von einzelnen, zueinander beabstandeten, Messpunkten ermittelt, woraus beispielsweise mittels Interpolation ein 2D Bild der Mahlgutoberfläche ermittelt wird. Die Messverfahren zur Ermittlung der Schichthöhe sind eine einfache und zuverlässige Möglichkeit, die Schichthöhe im Betrieb der Walzenmühle zu ermitteln.According to a further embodiment, the first measuring device is an optical measuring device, in particular a laser measuring device, infrared measuring device or an electromagnetic measuring device, such as a radar measuring device (microwaves in the range of 1-300 GHz). In the following, the measuring method is to be understood as meaning both the optical measuring method, the laser measuring method and the radar measuring method. In the case of the radar measurement, the measuring device is installed, for example, at a previously known distance from the surface of the grinding roller, preferably above the grinding roller. The layer height is preferably determined in a lateral edge area of the grinding roller using an optical measurement method or radar measurement. It is also conceivable that a surface area is detected, in particular by means of radar measurement, which extends, for example, over the entire width and length of the grinding roller or only over part of the grinding roller, for example the end area. With such a radar measurement, the surface of the material to be ground on the grinding roller is recorded over an area and, for example, the highest value of the layer height in this area is determined. For example, a plurality of measuring devices are provided, which are mounted above the surface of the grinding roller, for example evenly spaced from one another, around the circumference, in order to preferably detect a surface area of the grinding roller and to determine the layer height in this area, preferably over an area. For example, the height of the ground material is determined at a large number of individual measuring points that are spaced apart from one another, from which a 2D image of the ground material surface is determined, for example by means of interpolation. The measuring methods for determining the layer height are a simple and reliable way of determining the layer height when the roller mill is in operation.

Die zweite Messeinrichtung umfasst gemäß einer weiteren Ausführungsform einen Dehnungsmessstreifen. Insbesondere umfasst die zweite Messeinrichtung eine Mehrzahl von Dehnungsmesstreifen, vorzugsweise 2, 4,6, 8 oder 10 Dehnungsmesstreifen. Die Dehnungsmessstreifen sind beispielsweise an dem Randelement umfangsmäßig gleichmäßig zueinander beabstandet angebracht. Insbesondere ist ein Dehnungsmesstreifen an einer Schraube angebracht, mittels welcher das Randelement oder ein Segment des Randelements mit dem Walzengrundkörper verbunden ist. Der Dehnungsmesstreifen ermittelt die relative Dehnung oder Stauchung des Bereichs auf dem dieser angebracht ist, woraus die daran auftretenden Spannungen, insbesondere die auf die Randelemente und/ oder die Schrauben wirkenden Kräfte ermittelt wird.According to a further embodiment, the second measuring device comprises a strain gauge. In particular, the second measuring device comprises a plurality of strain gauges, preferably 2, 4, 6, 8 or 10 strain gauges. The strain gauges are circumferentially uniform, for example, on the edge element mounted spaced apart. In particular, a strain gauge is attached to a screw, by means of which the edge element or a segment of the edge element is connected to the roller body. The strain gauge determines the relative expansion or compression of the area to which it is attached, from which the stresses occurring thereon, in particular the forces acting on the edge elements and/or the screws, are determined.

Gemäß einer weiteren Ausführungsform ist die Steuerungseinrichtung derart ausgebildet ist, dass sie den Abstand zwischen dem Abstreiferelement und der Mahlwalze verringert, wenn die Schichthöhe einen vorabbestimmten Grenzwert übersteigt. Bei dem Grenzwert handelt es sich beispielsweise um 2mm bis 10mm, insbesondere 4mm bis 8mm, vorzugsweise 5mm. Vorzugsweise wird der Abstand erhöht, wenn die Schichthöhe den vorab bestimmten Grenzwert unterschreitet. Übersteigt die Schichthöhe den vorab bestimmten Grenzwert, kann auf einen Verschleiß des Abstreiferelements geschlossen werden. Der Grenzwert ist vorzugsweise in der Steuerungseinrichtung hinterlegt. Mit einer Verringerung des Abstandes wird der verschlissenen Bereich des Abstreiferelements kompensiert. Ebenso wird bei einer Erhöhung des Abstandes einem zu großen Verschleiß des Abstreiferelements entgegengewirkt. Unter dem Abstand ist insbesondere der Abstand zwischen dem Abstreiferelement und der Oberfläche des Walzengrundkörpers, insbesondere der Mahlfläche der Mahlwalze zu verstehen.According to a further embodiment, the control device is designed in such a way that it reduces the distance between the scraper element and the grinding roller when the layer height exceeds a predetermined limit value. The limit value is, for example, 2 mm to 10 mm, in particular 4 mm to 8 mm, preferably 5 mm. The distance is preferably increased if the layer height falls below the previously determined limit value. If the layer height exceeds the predetermined limit value, it can be concluded that the wiper element is worn. The limit value is preferably stored in the control device. By reducing the distance, the worn area of the wiper element is compensated. Likewise, if the distance is increased, excessive wear of the wiper element is counteracted. The distance is to be understood in particular as the distance between the scraper element and the surface of the roller base body, in particular the grinding surface of the grinding roller.

Die Steuerungseinrichtung ist gemäß einer weiteren Ausführungsform derart ausgebildet ist, dass sie den Abstand zwischen dem Abstreiferelement und der Mahlwalze verringert, wenn die Belastung, insbesondere die Dehnung des Randelements, einen vorabbestimmten Grenzwert übersteigt. Der Abstand wird mittels der Steuerungseinrichtung vorzugsweise erhöht, wenn die Belastung, insbesondere die relative Dehnung des Randelements, den vorabbestimmten Grenzwert unterschreitet.According to a further embodiment, the control device is designed in such a way that it reduces the distance between the scraper element and the grinding roller when the load, in particular the elongation of the edge element, exceeds a predetermined limit value. The distance is preferably increased by means of the control device when the load, in particular the relative expansion of the edge element, falls below the predetermined limit value.

Die Messeinrichtung ist gemäß einer weiteren Ausführungsform in Rotationsrichtung der Mahlwalze zwischen dem Abstreifer und dem Mahlspalt angeordnet ist. Dadurch wird die Funktion des Abstreifers überwacht, wobei die Schichtdicke an einem Ort ermittelt wird, an dem kein weiteres Material an die Walze angepresst wird.According to a further embodiment, the measuring device is arranged in the direction of rotation of the grinding roller between the scraper and the grinding gap. This monitors the function of the scraper, whereby the layer thickness is determined at a point where no other material is pressed against the roller.

Das Abstreiferelement ist vorzugsweise derart angeordnet, dass es an dem Randelement und/ oder an dem Endbereich der Mahlwalze angelagertes Material im Betrieb der Walzenmühle entfernt. Insbesondere ist das Abstreiferelement relativ zu den rotierbaren Mahlwalzen stationär oder beweglich angeordnet, sodass die Mahlwalzen relativ zu dem Abstreiferelement rotieren.The stripper element is preferably arranged in such a way that material accumulated on the edge element and/or on the end region of the grinding roller is removed during operation of the roller mill removed. In particular, the scraper element is arranged to be stationary or movable relative to the rotatable grinding rollers, so that the grinding rollers rotate relative to the scraper element.

Gemäß einer weiteren Ausführungsform weist die Walzenmühle einen stationären Maschinenrahmen auf und das Abstreiferelement ist an dem Maschinenrahmen angebracht. Der Maschinenrahmen umfasst beispielsweise mehrere Rahmenelemente, die mit Lagersteinen der Mahlwalzen verbunden sind, sodass die auf die Mahlwalzen wirkende Mahlkraft auf den Maschinenrahmen übertragen wird. Insbesondere umfasst ein Maschinenrahmen einer Walzenmühle ein sich im Wesentlichen in axialer Richtung der Mahlwalzen erstreckendes Rahmenelement, an dem vorzugsweise das Abstreiferelement angebracht ist. Das Abstreiferelement erstreckt sich von dem Maschinenrahmen in Richtung der Mahlwalze, insbesondere in dem Endbereich der Mahlwalze.According to a further embodiment, the roller mill has a stationary machine frame and the scraper element is attached to the machine frame. The machine frame includes, for example, several frame elements that are connected to bearing blocks of the grinding rollers, so that the grinding force acting on the grinding rollers is transmitted to the machine frame. In particular, a machine frame of a roller mill comprises a frame element which extends essentially in the axial direction of the grinding rollers and to which the scraper element is preferably attached. The scraper element extends from the machine frame in the direction of the grinding roller, in particular in the end area of the grinding roller.

Die Walzenmühle weist gemäß einer weiteren Ausführungsform zumindest zwei Abstreiferelemente auf, die an Endbereichen unterschiedlicher Walzenenden der Mahlwalze angeordnet sind. Die Abstreiferelemente sind vorzugweise an gegenüberliegenden Endbereichen einer Mahlwalze angeordnet. Vorzugsweise ist jedes Abstreiferelement an jeweils einer Halterung angebracht, die in Richtung der Mahlwalze bewegbar angebracht ist.According to a further embodiment, the roller mill has at least two scraper elements which are arranged at end regions of different roller ends of the grinding roller. The stripper elements are preferably arranged on opposite end areas of a grinding roller. Each scraper element is preferably attached to a respective holder which is attached such that it can be moved in the direction of the grinding roller.

Gemäß einer weiteren Ausführungsform weist das Abstreiferelement eine Abstreifplatte auf, die aus einem verschleißfesten Material, wie beispielsweise Wolframcarbid ausgebildet ist. Die Abstreifplatte ist an dem der Mahlwalze zugewandten Ende des Abstreiferelements angeordnet und ist im Betrieb der Walzenmühle mit dem abzustreifenden Material in Kontakt. Die Abtreifplatte ist daher einem hohen Verschleiß ausgesetzt, wobei ein verschleißfestes Material die Lebensdauer der Abstreifplatte verlängert.According to a further embodiment, the scraper element has a scraper plate which is formed from a wear-resistant material such as tungsten carbide. The stripper plate is arranged on the end of the stripper element facing the grinding roller and is in contact with the material to be stripped during operation of the roller mill. The stripper plate is therefore exposed to a high level of wear, with wear-resistant material extending the service life of the stripper plate.

Das Abstreiferelement weist gemäß einer weiteren Ausführungsform einen Arm auf, an dem die Abstreifplatte lösbar befestigt ist. Beispielsweise ist die Abstreifplatte an dem Arm verklemmt, oder verschraubt. Die Abstreifplatte steht vorzugsweise in Richtung der Mahlwalze über den Arm hervor. Eine lösbare Befestigung der Abstreifplatte des Abstreiferelements ermöglicht ein einfaches Austauschen der Abstreifplatte, die den verschleißintensivsten Bereich des Abstreiferelements darstellt. Ein Austausch des gesamten Abstreiferelements im Verschleißfall ist somit nicht notwendig.According to a further embodiment, the wiper element has an arm on which the wiper plate is detachably fastened. For example, the stripper plate is clamped or screwed to the arm. The stripper plate preferably protrudes beyond the arm in the direction of the grinding roller. A detachable fastening of the stripper plate of the stripper element enables easy replacement of the stripper plate, which represents the most wear-intensive area of the stripper element. It is therefore not necessary to replace the entire wiper element in the event of wear.

Die Erfindung umfasst auch ein Verfahren zum Betreiben einer Walzenmühle zum Zerkleinern von körnigem Material mit einer ersten Mahlwalze und einer zweiten Mahlwalze, die gegenüberliegend angeordnet und gegenläufig antreibbar sind, wobei zwischen den Mahlwalzen ein Mahlspalt ausgebildet ist und wobei zumindest eine der Mahlwalzen an einem Endbereich einer Mahlwalze ein Randelement aufweist, das derart ausgebildet ist, dass es sich über den Mahlspalt erstreckt und die gegenüberliegende Mahlwalze stirnseitig zumindest teilweise überdeckt, wobei an dem mit einem Randelement versehenen Endbereich der Mahlwalze ein Abstreiferelement zum zumindest teilweisen Entfernen von Material angeordnet ist, wobei das Verfahren zumindest den Schritt aufweist:

  • Ermitteln einer Schichthöhe an Mahlgut auf zumindest einer der Mahlwalzen und/ oder
  • Ermitteln einer Belastung des Randelements und
  • Einstellen des Abstands zwischen dem Abstreiferelement und der Mahlwalze in Abhängigkeit der ermittelten Schichthöhe und/ oder Belastung.
The invention also includes a method for operating a roller mill for comminuting granular material with a first grinding roller and a second grinding roller, which are arranged opposite one another and can be driven in opposite directions, with a grinding gap being formed between the grinding rollers and with at least one of the grinding rollers having a The grinding roller has an edge element which is designed in such a way that it extends across the grinding gap and at least partially covers the opposite grinding roller at the front, with a scraper element for at least partial removal of material being arranged on the end region of the grinding roller which is provided with an edge element, the method has at least the step:
  • Determining a layer height of ground material on at least one of the grinding rollers and/or
  • Determining a load on the edge element and
  • Adjusting the distance between the scraper element and the grinding roller depending on the determined layer height and/or load.

Die mit Bezug auf die Mahlwalze beschriebenen Vorteile treffen in verfahrensmäßiger Entsprechung auf das Verfahren m Betreiben einer Walzenmühle zum Zerkleinern von körnigem Material zu.The advantages described with reference to the grinding roller apply in a procedural correspondence to the method m operating a roller mill for comminuting granular material.

Das Material wird vorzugsweise an zwei mit jeweils einem Randelement versehenen Endbereichen der Mahlwalze entfernt. Gemäß einer weiteren Ausführungsform wird der Abstand verringert, wenn die ermittelte Schichthöhe einen vorab bestimmten Grenzwert übersteigt. Der Abstand wird gemäß einer weiteren Ausführungsform verringert wird, wenn die Belastung einen vorab bestimmten Grenzwert übersteigt.The material is preferably removed at two end regions of the grinding roller, each provided with an edge element. According to a further embodiment, the distance is reduced if the ascertained layer height exceeds a predetermined limit value. According to a further embodiment, the distance is reduced when the load exceeds a predetermined limit value.

Beschreibung der ZeichnungenDescription of the drawings

Die Erfindung ist nachfolgend anhand mehrerer Ausführungsbeispiele mit Bezug auf die beiliegenden Figuren näher erläutert.

Fig. 1
zeigt eine schematische Darstellung eines Ausschnitts einer Walzenmühle in einer Draufsicht gemäß einem Ausführungsbeispiel.
Fig. 2
zeigt eine schematische Darstellung eines Ausschnitts einer Walzenmühle in einer Draufsicht gemäß einem weiteren Ausführungsbeispiel.
Fig. 3
zeigt eine schematische Darstellung eines Ausschnitts einer Mahlwalze mit Abstreiferelementen in einer perspektivischen Absicht gemäß einem Ausführungsbeispiel.
Fig. 4
zeigt eine schematische Darstellung eines Abstreiferelements in einer perspektivischen Ansicht gemäß eines Ausführungsbeispiels.
Fig. 5
zeigt eine schematische Darstellung des Abstreiferelements der Fig. 4 in einer perspektivischen Rückansicht.
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 section of a roller mill in a plan view according to an embodiment.
2
shows a schematic representation of a section of a roller mill in a plan view according to a further embodiment.
3
shows a schematic representation of a section of a grinding roller with scraper elements in a perspective intention according to an embodiment.
4
shows a schematic representation of a wiper element in a perspective view according to an embodiment.
figure 5
shows a schematic representation of the wiper element 4 in a perspective rear view.

Fig. 1 zeigt eine Walzenmühle 10 mit einer ersten Mahlwalze 12 und einer zweiten Mahlwalze 14, die jeweils einen im Wesentlichen zylinderförmigen Walzengrundkörper aufweisen. Die Mahlwalzen 12, 14 sind gegenüberliegend angeordnet und gegenläufig antreibbar. Zwischen den Mahlwalzen 12, 14 ist ein Mahlspalt 16 ausgebildet, der sich in axialer Richtung erstreckt. Die Mahlwalzen 12, 14 sind nahezu parallel zueinander angeordnet, sodass der sich zwischen den Mahlwalzen 12, 14 erstreckende Mahlspalt 16 eine nahezu konstante Breite aufweist. Jeder der Mahlwalzen 12, 14 weist ferner eine Antriebswelle 30, 32 auf, die sich entlang der Mittelachse durch die jeweilige Mahlwalze 12, 14 erstreckt und die Mahlwalzen um ihre Mittelachse rotierend antreibt. Die erste und die zweite Mahlwalze 12, 14 weisen den gleichen Durchmesser auf, wobei die erste Mahlwalze 12 länger ist als die zweit Mahlwalze 14 sein kann. 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 almost parallel to one another, so that the grinding gap 16 extending between the grinding rollers 12, 14 has an almost 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, the first grinding roller 12 being longer than the second grinding roller 14 can be.

Die Mahlwalzen 12, 14 weisen jeweils einen ersten Endbereich 24, 28 und einen zweiten Endbereich 22, 26 auf, die an gegenüberliegenden Enden der Mahlwalze angeordnet sind. Der erste Endbereich 24 der ersten Mahlwalze 12 ist gegenüberliegend des ersten Endbereichs 28 der zweiten Mahlwalze 14 angeordnet, wobei der zweite Endbereich 22 der ersten Mahlwalze 12 gegenüberliegend des zweiten Endbereichs 26 der zweiten Mahlwalze 14 angeordnet ist.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 .

Die erste Mahlwalze 12 weist beispielhaft zwei Randelemente 18, 20 auf, die jeweils an einem Endbereich der Mahlwalze 12 angebracht sind. Das erste Randelement 18 ist an dem ersten Randbereich 22 der ersten Mahlwalze 12 angebracht und erstreckt sich in radialer Richtung über den Mahlspalt 16 hinweg, sodass es die Stirnseite der zweiten Mahlwalze 14 an dem ersten Endbereich 26 teilweise überdeckt. Das zweite Randelement 20 ist an dem zweiten Endbereich 24 der ersten Mahlwalze 12 angebracht und erstreckt sich in radialer Richtung über den Mahlspalt 16 hinweg, sodass es die Stirnseite der zweiten Mahlwalze 14 dem zweiten Endbereich 28 teilweise überdeckt. Zwischen den Randelementen 18 und der jeweiligen Stirnseite der zweiten Mahlwalze 14 ist jeweils ein stirnseitiger Spalt 34, 36 ausgebildet.The first grinding roller 12 has, for example, 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 at the second end area 24 attached to 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 over the second end region 28 . 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.

Die Randelemente 18, 20 umfassen vorzugsweise jeweils einen umlaufenden Kreisring, der beispielweise auch aus Segmenten bestehen kann und auf nicht dargestellte Weise an der jeweiligen Mahlwalze 12, 14 angebracht ist. Beispielsweise sind die Randelemente 18, 20 an der Stirnseite oder auf dem äußeren Umfang der Mahlwalze, insbesondere dem jeweiligen Walzengrundkörper, angebracht. Auf dem äußeren Umfang der jeweiligen Mahlwalze 12, 14 ist beispielsweise eine umlaufende Nut angeordnet, in der jeweils ein Randelement 18, 20 angeordnet ist. Die Randelemente 18, 20 sind aus einem verschleißfesten Material, wie beispielsweise Stahl, ausgebildet und weisen insbesondere auf der zu dem Mahlspalt 16 weisenden Innenseite eine verschleißfeste Beschichtung oder eine Mehrzahl von beispielsweise plattenförmigen Verschleißschutzelementen auf. Die Randelemente 18, 20 weisen beispielsweise eine Dicke von 10 mm bis 100 mm und überdecken die gegenüberliegenden Mahlwalzen 12, 14 um etwa 2-20%, insbesondere 4-10%, vorzugsweise 3-6% des Walzendurchmessers.The edge elements 18, 20 preferably each comprise a circumferential circular ring, which can also consist of segments, for example, and 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 wear-resistant coating or a plurality of, for example, plate-shaped anti-wear elements, particularly on the inside facing the grinding gap 16. The edge elements 18, 20 have a thickness of 10 mm to 100 mm, for example, and cover the opposite grinding rollers 12, 14 by about 2-20%, in particular 4-10%, preferably 3-6% of the roller diameter.

Fig. 2 zeigt eine weitere Ausführungsform einer Mahlwalze mit Randelementen 18, 20, wobei die Mahlwalze im Wesentlichen der in Fig. 1 dargestellten Mahlwalze entspricht mit dem Unterschied, dass in dem Ausführungsbeispiel der Fig. 2 jede der Mahlwalzen 12, 14 jeweils ein Randelement 18, 20 aufweist. Die erste und die zweite Mahlwalze 12, 14 weisen den gleichen Durchmesser und die gleiche Länge auf und sind im Wesentlichen baugleich ausgebildet. 2 shows a further embodiment of a grinding roller with edge elements 18, 20, wherein the grinding roller essentially corresponds to that in 1 shown grinding roller corresponds with the difference that in the embodiment of 2 each of the grinding rollers 12, 14 has a respective edge element 18, 20. The first and the second grinding roller 12, 14 have the same diameter and the same length and are of essentially identical construction.

Die Randelemente 18, 20 sind bezogen auf die Endbereiche 22 -28 der Mahlwalzen 12, 14 diagonal gegenüberliegend angeordnet. Die erste Mahlwalze 12 weist an ihrem ersten Endbereich 24 ein Randelement 18 auf, das sich in radialer Richtung über den Mahlspalt 16 erstreckt und die Stirnseite der zweiten Mahlwalze 14 an dem ersten Endbereich 28 teilweise überdeckt. Die zweite Mahlwalze 14 weist an ihrem zweiten Endbereich 26 ein Randelement 20 auf, das sich in radialer Richtung über den Mahlspalt 16 erstreckt und die Stirnseite der ersten Mahlwalze 12 an ihrem zweiten Randbereich 22 teilweise überdeckt. Das zweite Randelement 20 ist mit Bezug auf das erste Randelement 18 an dem diagonal gegenüberliegenden Endbereich 26 der zweiten Mahlwalze 14 angeordnet. Die Mahlwalzen 12, 14 sind in axialer Richtung versetzt angeordnet, sodass zwischen dem ersten Randelement 18 und der Stirnseite der zweiten Mahlwalze 14 ist ein erster stirnseitiger Spalt 34 ausgebildet ist und zwischen dem zweiten Randelement 20 und der Stirnseite der ersten Mahlwalze 12 ein zweiter Stirnseitiger Spalt 36 ausgebildet ist. Der erste und der zweite stirnseitige Spalt 34, 36 erstrecken sich jeweils in radialer Richtung.The edge elements 18, 20 are arranged diagonally opposite one another in relation to the end regions 22-28 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 element 20 is arranged on the diagonally opposite end region 26 of the second grinding roller 14 with respect to the first edge element 18 . The grinding rollers 12, 14 are arranged offset in the axial direction, so that between the first edge element 18 and the end face of the second Grinding roller 14 is a first end-side gap 34 is formed and between the second edge element 20 and the end face of the first grinding roller 12 a second end-side gap 36 is formed. The first and the second end gap 34, 36 each extend in the radial direction.

Fig. 3 zeigt einen Ausschnitt einer ersten Mahlwalze 12 der Walzenmühle 10 gemäß Fig.1. Die Randelemente 18, 20 umfassen beispielhaft eine Mehrzahl von teilkreisförmigen Segmenten, die jeweils an die Stirnfläche eines jeweiligen Endbereichs der Mahlwalze 12 angeschraubt sind. Jedes Segment ist mit einer Mehrzahl von Schrauben oder Bolzen an der Stirnseite der Mahlwalze 12 befestigt. 3 shows a section of a first grinding roller 12 of the roller mill 10 according to FIG Fig.1 . The edge elements 18, 20 comprise, for example, a plurality of segments in the shape of a part circle, each of which is screwed to the end face of a respective end region of the grinding roller 12. Each segment is fastened to the face of the grinding roller 12 with a plurality of screws or bolts.

Fig. 3 zeigt außerdem zwei Abstreiferelemente 42, 44, die jeweils an einer Halterung 38, 40 angebracht sind und sich jeweils in Richtung eines jeweiligen Endbereichs der Mahlwalze 12 erstrecken. Die Halterungen 38, 40 sind vorzugsweise jeweils an einem nicht dargestellten Maschinenrahmen befestigt, wobei an dem Maschinenrahmen insbesondere die Mahlwalzen 12, 14 gelagert sind. Die Abstreiferelemente 42, 44 sind zu der Mahlwalze 12 und dem Randelement 18, 20 der Mahlwalze 12 beabstandet angeordnet, sodass die Abstreifer die Mahlwalze 12 und die Randelemente 18, 20 nicht berühren. Das erste Abstreiferelement 42 ist derart angebracht, dass es dem ersten Endbereich 22 der Mahlwalze 12 gegenüberliegt, wobei sich das erste Abstreiferelement 42 in radialer Richtung der Mahlwalze 12 entlang des ersten Randelements 18 erstreckt und im Wesentlichen parallel zu diesem ausgerichtet ist. Es sind jedoch auch andere Ausrichtungen möglich. Das zweite Abstreiferelement 44 ist in entsprechender Weise an dem zweiten Endbereich 24 und dem zweiten Randelement 20 der Mahlwalze 12 angeordnet. Die Abstreiferelemente 42, 44 erstrecken sich jeweils entlang an der in axialer Richtung der Mahlwalze 12 nach Innen weisenden Fläche der Randelemente 18, 20. Die Abstreiferelemente 42, 44 sind beispielsweise identisch ausgebildet. 3 FIG. 12 also shows two scraper elements 42, 44 which are each attached to a holder 38, 40 and each extend in the direction of a respective end region of the grinding roller 12. The holders 38, 40 are preferably each attached to a machine frame, not shown, with the grinding rollers 12, 14 in particular being mounted on the machine frame. The scraper elements 42, 44 are arranged at a distance from the grinding roller 12 and the edge element 18, 20 of the grinding roller 12, so that the scraper does not touch the grinding roller 12 and the edge elements 18, 20. The first scraper element 42 is attached in such a way that it faces the first end region 22 of the grinding roller 12, the first scraper element 42 extending in the radial direction of the grinding roller 12 along the first edge element 18 and being aligned essentially parallel thereto. However, other orientations are also possible. The second stripper element 44 is arranged in a corresponding manner on the second end area 24 and the second edge element 20 of the grinding roller 12 . The scraper elements 42, 44 each extend along the surface of the edge elements 18, 20 pointing inwards in the axial direction of the grinding roller 12. The scraper elements 42, 44 are, for example, of identical design.

Die Halterungen 38, 40 sind vorzugsweise derart ausgebildet, dass sie in und/ oder entgegen der Richtung der Mahlwalze 12 bewegbar sind, sodass bei einer Bewegung der Halterungen 38, 40 in oder entgegen der Richtung der Mahlwalze der Abstand zwischen der Mahlwalze, insbesondere der Oberfläche der Mahlwalze 12, 14 und dem Abstreiferelement 42, 44 verringert oder erhöht wird. Die Halterungen 38, 40 sind vorzugsweise linear in Richtung der Mahlwalze 12, 14 oder von der Mahlwalze 12, 14 weg bewegbar. Bei den Halterungen 38, 40 handelt es sich beispielsweise um jeweils eine Teleskopstange oder eine Spindel, die vorzugsweise mittels eines nicht dargestellten Elektromotors oder manuell mittels eines Handrades antreibbar sind.The holders 38, 40 are preferably designed in such a way that they can be moved in and/or counter to the direction of the grinding roller 12, so that when the holders 38, 40 move in or counter to the direction of the grinding roller, the distance between the grinding roller, in particular the surface of the grinding roller 12, 14 and the scraper element 42, 44 is reduced or increased. The holders 38, 40 are preferably linearly movable in the direction of the grinding roller 12, 14 or away from the grinding roller 12, 14. The brackets 38, 40 are for example, a telescopic rod or a spindle, which can be driven preferably by means of an electric motor, not shown, or manually by means of a handwheel.

Fig. 3 zeigt des Weiteren eine erste Messeinrichtung 62 zum Ermitteln der Schichtdicke des auf der Oberfläche der Mahlwalze anhaftenden Mahlguts. Die erste Messeinrichtung 62 ist beispielsweise eine optische Messeinrichtung, wobei die Schichtdicke beispielsweise mittels eines Lasers ermittelt wird. Die erste Messeinrichtung 62 ist vorzugsweise derart angeordnet, dass die Schichtdicke des Mahlguts an einem Endbereich der Mahlwalze 12, 14, insbesondere in der Nähe oder an einem der Randelemente 18, 20 ermittelt wird. Vorzugsweise ist die erste Messeinrichtung 62 in Rotationsrichtung der Mahlwalze 12 hinter dem Abstreiferelement 42, 44 angebracht, sodass die Schichtdicke im Betrieb der Walzenmühle 10 umfangsmäßig zwischen dem Abstreiferelement 42, 44 und dem Mahlspalt 16 ermittelt wird. Die Roationsrichtung der Mahlwalze 12 ist in Fig. 3 mit einem Pfeil dargestellt. Die erste Messeinrichtung 62 ist beispielsweise an dem voran beschriebenen Maschinenrahmen angebracht und stationär relativ zu den rotierbaren Mahlwalzen 12, 14 angeordnet. 3 FIG. 1 also shows a first measuring device 62 for determining the layer thickness of the material to be ground adhering to the surface of the grinding roller. The first measuring device 62 is, for example, an optical measuring device, the layer thickness being determined, for example, by means of a laser. The first measuring device 62 is preferably arranged in such a way that the layer thickness of the material to be ground is determined at an end region of the grinding roller 12, 14, in particular in the vicinity of or on one of the edge elements 18, 20. The first measuring device 62 is preferably mounted behind the scraper element 42, 44 in the direction of rotation of the grinding roller 12, so that the layer thickness is determined circumferentially between the scraper element 42, 44 and the grinding gap 16 during operation of the roller mill 10. The direction of rotation of the grinding roller 12 is in 3 shown with an arrow. The first measuring device 62 is attached, for example, to the machine frame described above and is arranged in a stationary manner relative to the rotatable grinding rollers 12 , 14 .

Die Walzenmühle 10 weist des Weiteren eine zweite Messeinrichtung 64 auf, die an einem Randelement 18, 20 angebracht ist und derart ausgebildet ist, dass sie die auf das jeweilige Randelement 18, 20 wirkende Belastung ermittelt. Unter Belastung ist beispielsweise die auf das Randelement 18, 20 wirkende Kraft und/ oder die in dem jeweiligen Randelement 18, 20 auftretenden Spannungen zu verstehen. Bei der zweiten Messeinrichtung 64 handelt es sich beispielsweise um einen oder eine Mehrzahl von Dehnungsmessstreifen. Beispielsweise ist der Dehnungsmesstreifen auf dem Randelement 18, 20 angebracht, um die in dem Randelement auftretenden Spannungen, insbesondere die auf das Randelement wirkenden Kräfte, zu ermitteln. Es ist ebenfalls denkbar, eine Mehrzahl von Dehnungsmesstreifen an unterschiedlichen Positionen auf dem Randelement 18, 20 anzubringen. Beispielsweise sind eine oder eine Mehrzahl von Schrauben zum Befestigen des Randelements 18, 20 an dem Walzengrundkörper der Mahlwalze 12, 14 mit jeweils einem Dehnungsmessstreifen versehen. Die zweite Messeinrichtung 64 ist vorzugsweise in Rotationsrichtung der Mahlwalze 12, 14 hinter dem Abstreiferelement 42, 44 und vor dem Mahlspalt 16 angeordnet.The roller mill 10 also has a second measuring device 64 which is attached to an edge element 18, 20 and is designed in such a way that it determines the load acting on the respective edge element 18, 20. Load is to be understood, for example, as the force acting on the edge element 18, 20 and/or the stresses occurring in the respective edge element 18, 20. The second measuring device 64 is, for example, one or a plurality of strain gauges. For example, the strain gauge is attached to the edge element 18, 20 in order to determine the stresses occurring in the edge element, in particular the forces acting on the edge element. It is also conceivable to attach a plurality of strain gauges to different positions on the edge element 18, 20. For example, one or a plurality of screws for fastening the edge element 18, 20 to the roller body of the grinding roller 12, 14 are each provided with a strain gauge. The second measuring device 64 is preferably arranged behind the stripper element 42, 44 and in front of the grinding gap 16 in the direction of rotation of the grinding roller 12, 14.

Die Walzenmühle 10 umfasst des Weiteren eine Steuerungseinrichtung 66 zum Einstellen des Abstands zwischen dem Abstreiferelement 42, 44 und der Oberfläche der Mahlwalze 12, 14. Die Steuerungseinrichtung 66 steht mit der ersten und/ oder der zweiten Messeinrichtung 62, 64 derart in Verbindung, dass die mittels der jeweiligen Messeinrichtung 62, 64 ermittelten Daten an die Steuerungseinrichtung 66 übermittelt werden. Die Steuerungseinrichtung 66 steht des Weiteren mit der Halterung 38, 40, vorzugsweise mit beiden Halterungen 38, 40 der Abstreiferelemente 42, 44 in Verbindung. Insbesondere ist die Steuerungseinrichtung 66 mit einem Elektromotor verbunden, der die Halterungen 38, 40 der Abstreiferelemente 42, 44 bewegt, vorzugsweise in Richtung der Mahlwalze 12, 14 oder von der Mahlwalze 12, 14 weg. Die Steuerungseinrichtung 66 ist derart mit den Halterungen 38, 40 und/ oder dem Elektromotor verbunden, dass sie die Halterungen mittels eines Steuerungssignals zur Bewegung in Richtung der Mahlwalze 12, 14 oder von der Mahlwalze 12, 14 wegbewegen kann.The roller mill 10 also includes a control device 66 for adjusting the distance between the scraper element 42, 44 and the surface of the grinding roller 12, 14. The control device 66 communicates with the first and/or the second measuring device 62, 64 in such a way that the data determined by means of the respective measuring device 62, 64 is transmitted to the control device 66. The control device 66 is also connected to the holder 38, 40, preferably to both holders 38, 40 of the wiper elements 42, 44. In particular, the control device 66 is connected to an electric motor, which moves the holders 38, 40 of the scraper elements 42, 44, preferably in the direction of the grinding roller 12, 14 or away from the grinding roller 12, 14. The control device 66 is connected to the holders 38, 40 and/or the electric motor in such a way that it can move the holders in the direction of the grinding roller 12, 14 or away from the grinding roller 12, 14 by means of a control signal.

Fig. 3 zeigt lediglich die Anordnung der Abtreifelemente 42, 44 an einer Walzenmühle gemäß Fig.1. Eine in Fig. 2 dargestellte Walzenmühle 10 weist beispielsweise ebenfalls zwei Abstreiferelemente 42, 44 auf. Jede Mahlwalze 12, 14 der in Fig. 2 dargestellten Walzenmühle 10 weist jeweils ein Abstreiferelement 42, 44 auf, das beispielsweise an einem Walzenrahmen angebracht ist und sich entsprechend dem Ausführungsbeispiel der Fig. 3 in Richtung eines jeweiligen ein Randelement 18, 20 aufweisenden Endbereichs der Mahlwalze 12, 14 erstrecket. Ebenso ist es denkbar, dass an jedem Endbereich der Mahlwalze jeweils eine erste Messeinrichtung 62 und an jedem Randelement 18, 20 jeweils eine zweite Messeinrichtung 64 angebracht ist. Beispielsweise sind alle Messeinrichtungen 62, 64 mit einer Steuerungseinrichtung 66 verbunden. 3 FIG. 1 only shows the arrangement of the stripping elements 42, 44 on a roller mill according to FIG Fig.1 . one inside 2 The roller mill 10 shown also has, for example, two stripper elements 42, 44. Each grinding roller 12, 14 of the in 2 Roller mill 10 shown has a scraper element 42, 44, which is attached, for example, to a roller frame and corresponding to the embodiment of FIG 3 in the direction of a respective end region of the grinding roller 12, 14 having an edge element 18, 20. It is also conceivable that a first measuring device 62 is attached to each end region of the grinding roller and a second measuring device 64 is attached to each edge element 18 , 20 . For example, all measuring devices 62, 64 are connected to a control device 66.

Zur Einstellung des Abstands zwischen dem Abstreiferelement 42, 44 und der Oberfläche der Mahlwalze 12, 14 vergleicht die Steuerungseinrichtung 66 beispielsweise die von der ersten und/ oder der zweiten Messeinrichtung 62, 64 übermittelten Messwerte mit einem entsprechenden vorab bestimmten Grenzwert. Beispielsweise vergleicht die Steuerungseinrichtung 66 den mittels der ersten Messeinrichtung 62 übermittelten Wert der Schichthöhe des Mahlguts auf der Mahlwalze 12, 14 mit einem vorab bestimmten Grenzwert der Schichthöhe, der in der Steuerungseinrichtung 66 hinterlegt ist. Die Steuerungseinrichtung 66 ist vorzugsweise derart ausgebildet und eingerichtet, dass sie bei einem Überschreiten der ermittelten Schichthöhe von dem vorab bestimmten Grenzwert, den Abstand zwischen dem jeweiligen Abstreiferelement 42, 44 und der Oberfläche der jeweiligen Mahlwalze 12, 14 verringert. Dazu übermittelt die Steuerungseinrichtung 66 beispielsweise ein Steuersignal an den Elektromotor oder an die Halterungen 38, 40, sodass die Halterungen 38, 40 und die daran fest angebrachten Abstreiferelemente 42, 44 in Richtung der Mahlwalze 12, 14, insbesondere in Richtung der Mahlwalzenoberfläche, bewegt werden und sich der Abstand zwischen den Abstreiferelementen 42, 44 und der Oberfläche der Mahlwalze 12, 14 verringert. Bei dem vorabbestimmten Grenzwert der Schichthöhe handelt es sich beispielsweise um 2mm bis 10mm, insbesondere 4mm bis 8mm, vorzugsweise 5mm. Die Steuerungseinrichtung 66 ist vorzugsweise derart ausgebildet und eingerichtet, dass sie bei einem Unterschreiten der ermittelten Schichthöhe von dem vorab bestimmten Grenzwert, den Abstand zwischen dem jeweiligen Abstreiferelement 42, 44 und der Oberfläche der jeweiligen Mahlwalze 12, 14 erhöht. Eine erhöhte Schichtdicke an Mahlgut auf der Mahlwalze 12, 14 lässt auf einen Verschleiß des Abstreiferelements 42, 44 schließen, wobei eine Verringerung des Abstandes des Abstreiferelements 42, 44 zu der Oberfläche der Mahlwalze einer Verschleißnachstellung des Abstreiferelements 42, 44 entspricht, sodass der Verschleiß des Abstreiferelements 42, 44 ausgeglichen wird.To set the distance between the scraper element 42, 44 and the surface of the grinding roller 12, 14, the control device 66 compares, for example, the measured values transmitted by the first and/or the second measuring device 62, 64 with a corresponding limit value determined in advance. For example, the control device 66 compares the value of the layer height of the material to be ground on the grinding roller 12, 14 transmitted by means of the first measuring device 62 with a previously determined limit value of the layer height, which is stored in the control device 66. The control device 66 is preferably designed and set up in such a way that it reduces the distance between the respective stripper element 42, 44 and the surface of the respective grinding roller 12, 14 when the determined layer height exceeds the predetermined limit value. For this purpose, the control device 66 transmits, for example, a control signal to the electric motor or to the holders 38, 40, so that the holders 38, 40 and the stripper elements 42, 44 fixed thereto can be moved in the direction of the grinding roller 12, 14, in particular in the direction of the Grinding roller surface are moved and the distance between the scraper elements 42, 44 and the surface of the grinding roller 12, 14 is reduced. The predetermined limit value of the layer height is, for example, 2 mm to 10 mm, in particular 4 mm to 8 mm, preferably 5 mm. The control device 66 is preferably designed and set up such that it increases the distance between the respective stripper element 42, 44 and the surface of the respective grinding roller 12, 14 when the determined layer height falls below the predetermined limit value. An increased layer thickness of ground material on the grinding roller 12, 14 indicates wear of the scraper element 42, 44, with a reduction in the distance between the scraper element 42, 44 and the surface of the grinding roller corresponding to a wear adjustment of the scraper element 42, 44, so that the wear of the Stripper element 42, 44 is compensated.

Beispielsweise vergleicht die Steuerungseinrichtung 66 den mittels der zweiten Messeinrichtung 64 übermittelten Wert der Belastung, vorzugsweise der Dehnung der Randelemente 18, 20 und / oder die auf die Randelemente 18,20 und/ oder die Schrauben wirkenden Kräfte, mit einem vorab bestimmten Grenzwert der jeweiligen Belastung, vorzugsweise der Dehnung, der in der Steuerungseinrichtung 66 hinterlegt ist. Die Steuerungseinrichtung 66 ist vorzugsweise derart ausgebildet und eingerichtet, dass sie bei einem Überschreiten der ermittelten Belastung, insbesondere der Dehnung, des vorab bestimmten Grenzwerts, den Abstand zwischen dem jeweiligen Abstreiferelement 42, 44 und der Oberfläche der jeweiligen Mahlwalze 12, 14 verringert. Dies erfolgt vorzugsweise wie voran beschrieben. Die Steuerungseinrichtung 66 ist vorzugsweise derart ausgebildet und eingerichtet, dass sie bei einem Unterschreiten der ermittelten Belastung, insbesondere der Dehnung, des vorab bestimmten Grenzwerts, den Abstand zwischen dem jeweiligen Abstreiferelement 42, 44 und der Oberfläche der jeweiligen Mahlwalze 12, 14 verringert.For example, the control device 66 compares the load value transmitted by the second measuring device 64, preferably the elongation of the edge elements 18, 20 and/or the forces acting on the edge elements 18, 20 and/or the screws, with a previously determined limit value of the respective load , preferably the elongation that is stored in the control device 66. The control device 66 is preferably designed and set up in such a way that it reduces the distance between the respective stripper element 42, 44 and the surface of the respective grinding roller 12, 14 when the determined load, in particular the elongation, exceeds the predetermined limit value. This is preferably done as described above. The control device 66 is preferably designed and set up in such a way that it reduces the distance between the respective stripper element 42, 44 and the surface of the respective grinding roller 12, 14 when the determined load, in particular the elongation, falls below the predetermined limit value.

Fig. 4 zeigt eine vergrößerte Ansicht eines beispielhaften Abstreiferelements 42, 44. Das Abstreiferelement 42, 44 weist eine Befestigungsplatte 46 auf, die in der montierten Position des Abstreiferelements 42, 44 an der Halterung 38, 40 angebracht ist. Die Befestigungsplatte weist eine Mehrzahl von Befestigungslöchern 48 auf, die der Befestigung des Abstreiferelements 42, 44 an der Halterung 38, 40 beispielsweise mittels Schrauben dienen. 4 12 shows an enlarged view of an exemplary wiper element 42,44. The wiper element 42,44 has a mounting plate 46 which is attached to the bracket 38,40 in the assembled position of the wiper element 42,44. The mounting plate has a plurality of mounting holes 48, which are used to attach the wiper element 42, 44 to the holder 38, 40, for example by means of screws.

An der Befestigungsplatte 46 ist ein Arm 50 angebracht, der sich beispielsweise in einem Winkel von etwa 30-60°, insbesondere etwa 45° zu der Befestigungsplatte 46 in Richtung der nicht dargestellten Mahlwalze 12, 14 erstreckt. An dem Arm 50 ist eine Abstreifplatte 52 angebracht, die mittels zwei Schrauben 54 und einer Klemmplatte 56 an dem Arm 50 befestigt ist. Die Abstreifplatte erstreckt sich parallel zu dem Arm 50 über das der Befestigungsplatte 46 abgewandte Ende des Arms hinaus, sodass die Abstreifplatte 52 an dem Arm 50 in radialer Richtung der Mahlwalze 12, 14 hervorsteht. Die Abstreifplatte 52 ist zwischen der Klemmplatte 56 und dem Arm 50 verklemmt, sodass diese in einem Verschleißfall einfach austauschbar ist. Beispielhaft ist die Abstreifplatte 58 in einer Klemmaufnahme 58 angeordnet, die zwischen der Klemmplatte 56 und dem Arm 50 angeordnet und mittels der Klemmplatte 56 und den Schrauben 54 verklammt ist.On the mounting plate 46, an arm 50 is attached, for example, at an angle of about 30-60 °, in particular about 45 ° to the mounting plate 46 in the direction of not illustrated grinding roller 12, 14 extends. Attached to the arm 50 is a stripper plate 52 which is secured to the arm 50 by means of two screws 54 and a clamping plate 56 . The stripper plate extends parallel to the arm 50 beyond the end of the arm facing away from the fastening plate 46, so that the stripper plate 52 on the arm 50 protrudes in the radial direction of the grinding roller 12, 14. The stripper plate 52 is clamped between the clamping plate 56 and the arm 50 so that it can be easily replaced if it becomes worn. By way of example, the stripper plate 58 is arranged in a clamping receptacle 58 which is arranged between the clamping plate 56 and the arm 50 and is clamped by means of the clamping plate 56 and the screws 54 .

Die Vorderkante der Abstreifplatte 52 erstreckt sich in dem Ausführungsbeispiel der Fig. 4 in einem Winkel zu Oberfläche der jeweiligen Mahlwalze 12, 14, sodass der Abstand zwischen der Abstreifplatte 52 und der Oberfläche der Mahlwalze 12, 14 in Richtung des Mahlwalzenendes geringer ist. Der Winkel zwischen der Abstreifplatte 52 und der Oberfläche der Mahlwalze 12, 14 beträgt beispielsweise 45° - 135° Es ist ebenfalls denkbar, dass sich die Vorderkante der Abstreifplatte 52 im Wesentlichen parallel zu der Oberfläche der jeweiligen Mahlwalze 12, 14 erstreckt, insbesondere in axialer Richtung der Mahlwalze. Die Seitenfläche der Abstreifplatte 52, sowie die Seitenfläche des Arms 50 erstrecken sich entlang des jeweiligen Randelements 18, 20. Insbesondere ist zwischen dem Abstreiferelement 42, 44 und der Oberfläche der Mahlwalze 12, 14 ein Spalt von 2mm bis 10mm, vorzugsweise 4mm bis 8mm, insbesondere 5mm ausgebildet.The front edge of the stripper plate 52 extends in the embodiment of FIG 4 at an angle to the surface of the respective grinding roller 12, 14, so that the distance between the stripper plate 52 and the surface of the grinding roller 12, 14 is smaller in the direction of the grinding roller end. The angle between the stripper plate 52 and the surface of the grinding roller 12, 14 is 45° - 135°, for example. It is also conceivable that the front edge of the stripper plate 52 extends essentially parallel to the surface of the respective grinding roller 12, 14, in particular in the axial direction direction of the grinding roller. The side surface of the stripper plate 52 and the side surface of the arm 50 extend along the respective edge element 18, 20. In particular, there is a gap of 2mm to 10mm, preferably 4mm to 8mm, between the stripper element 42, 44 and the surface of the grinding roller 12, 14. formed in particular 5mm.

Die Befestigungsplatte 46, der Arm, die Klemmaufnahme 58 und die Klemmplatte 56 sind beispielsweise aus Stahl ausgebildet. Die Abstreifplatte ist beispielsweise aus einem hochverschleißfesten Material, wie Wolframcarbid ausgebildet.The mounting plate 46, arm, clamp seat 58 and clamp plate 56 are formed of steel, for example. The stripper plate is formed, for example, from a highly wear-resistant material such as tungsten carbide.

Fig. 5 zeigt eine Rückansicht des Abstreiferelements 42, 44 der Fig. 4. Der Arm 50 weist beispielhaft ein im Wesentlichen U-förmiges Profil auf, wobei die Klemmplatte 56 und die Klemmaufnahme 58 mittels Schrauben 54 und Muttern an dem Arm 50 angebracht sind. figure 5 shows a rear view of the wiper element 42, 44 of 4 . By way of example, the arm 50 has a substantially U-shaped profile, with the clamping plate 56 and the clamping receptacle 58 being attached to the arm 50 by means of screws 54 and nuts.

Im Betrieb der Walzenmühle 10 verhindern die Randelemente 18, 20 ein seitliches Austreten von Material aus dem Mahlspalt 16. Auf der Oberfläche der Mahlwalzen 12, 14 wird durch die Ablagerung von Material ein autogener Verschleißschutz aufgebaut. Die Abstreiferelemente 42, 44 streifen während der Rotation der Mahlwalze 12, 14 an den Endbereichen der Mahlwalze 12, 14 abgelagertes Material ab und sorgen somit dafür, dass die autogene Verschleißschutzschicht auch in den Endbereichen der Mahlwalzen 12, 14, an denen die Randelemente angebracht sind, nicht über eine bestimmte Dicke ansteigt, sodass die Randelemente zuverlässig vor hohem Druck durch abgelagertes Material geschützt werden.During operation of the roller mill 10, the edge elements 18, 20 prevent material from escaping laterally from the grinding gap 16. Autogenous wear protection is built up on the surface of the grinding rollers 12, 14 as a result of the deposition of material. During the rotation of the grinding roller 12, 14, the scraper elements 42, 44 strip off material deposited on the end regions of the grinding roller 12, 14 and thus ensure that the autogenous wear protection layer also in the end areas of the grinding rollers 12, 14, to which the edge elements are attached, does not rise above a specific thickness, so that the edge elements are reliably protected against high pressure from deposited material.

BezugszeichenlisteReference List

1010
Walzenmühleroller mill
1212
erste Mahlwalzefirst grinding roller
1414
zweite Mahlwalzesecond grinding roller
1616
Mahlspaltmilling gap
1818
erstes Randelementfirst boundary element
2020
zweites Randelementsecond boundary element
2222
erster Endbereich der ersten Mahlwalzefirst end area of the first grinding roller
2424
zweiter Endbereich der ersten Mahlwalzesecond end area of the first grinding roller
2626
zweiter Endbereich der zweiten Mahlwalzesecond end area of the second grinding roller
2828
erster Endbereich der zweiten Mahlwalzefirst end portion of the second grinding roller
3030
Antriebswelle der ersten MahlwalzeDrive shaft of the first grinding roller
3232
Antriebswelle der zweiten MahlwalzeDrive shaft of the second grinding roller
3434
erster stirnseitiger Spaltfirst frontal gap
3636
zweiter stirnseitiger Spaltsecond front gap
3838
Halterungbracket
4040
Halterungbracket
4242
erstes Abstreiferelementfirst wiper element
4444
zweites Abstreiferelementsecond wiper element
4646
Befestigungsplattemounting plate
4848
Befestigungslöchermounting holes
5050
Armpoor
5252
Abstreifplattestripper plate
5454
Schraubenscrews
5656
Klemmplatteclamp plate
5858
Klemmaufnahmeclamp mount
6060
MutterMother
6262
erste Messeinrichtungfirst measuring device
6464
zweite Messeinrichtungsecond measuring device
6666
Steuerungseinrichtungcontrol device

Claims (14)

  1. Roller mill (10) for comminution of a granular material having
    a first grinding roller (12) and a second grinding roller (14), which are arranged opposite each other and can be driven in opposite directions,
    wherein a milling gap (16) is formed between the grinding rollers (12, 14) and wherein at least one of the grinding rollers (12, 14) has an edge element (18, 20) in an end region (22, 24, 26, 28) of the grinding roller (12, 14), which is designed such that it extends over the milling gap (16) and at least partly covers the end face of the opposite grinding roller (12, 14),
    wherein a scraper element (42, 44) for at least partially removing material is arranged in the end region (22, 24, 26, 28) of the grinding roller (12, 14) provided with an edge element (18, 20), characterised in that
    the roller mill has a measuring device (62, 64) for measuring the layer thickness of the material to be ground on at least one of the grinding rollers (12, 14) and/or for measuring the load on the edge element (18, 20) and
    a control device (66), which is connected to the measuring device (62, 64) and is designed to reduce or increase the distance between the scraper element (42, 44) and the grinding roller (12, 14) depending on the measured layer thickness and/or load.
  2. Roller mill (10) according to claim 1, wherein the scraper element (42, 44) is attached to a mount (38, 40) and wherein the mount (38, 40) is designed to be movable in the direction of the grinding roller (12, 14).
  3. Roller mill (10) according to any one of the preceding claims, wherein the roller mill has a first measuring device (62) for measuring the layer height of the material to be ground on the grinding roller (12, 14) and a second measuring device (64) for measuring the load on the edge element (18, 20).
  4. Roller mill (10) according to any one of the preceding claims, wherein the first measuring device (62) is an optical measuring device, in particular a laser measuring device or infrared measuring device, or an electromagnetic measuring device.
  5. Roller mill (10) according to any one of the preceding claims, wherein the second measuring device (64) is a strain gauge.
  6. Roller mill (10) according to any one of the preceding claims, wherein the control device (66) is designed such that it reduces the distance between the scraper element (42, 44) and the grinding roller (12, 14) when the layer height exceeds a predetermined limit.
  7. Roller mill (10) according to any one of the preceding claims, wherein the control device (66) is designed such that it reduces the distance between the scraper element (42, 44) and the grinding roller (12, 14) when the load exceeds a predetermined limit.
  8. Roller mill (10) according to any one of the preceding claims, wherein the measuring device (62, 64) is arranged in the direction of rotation of the grinding roller (12, 14) between the scraper element (42, 44) and the milling gap (16).
  9. Roller mill (10) according to any one of the preceding claims, wherein the roller mill (12, 14) has a stationary machine frame and the scraper element (42, 44) is attached to the machine frame (38).
  10. Roller mill (10) according to any one of the preceding claims, wherein the roller mill (10) has at least two scraper elements (42, 44), which are arranged in end regions of different roller ends of the grinding roller (12, 14).
  11. Roller mill (10) according to any one of the preceding claims, wherein the scraper element (42, 44) has a stripper plate (52), which is made from a wear-resistant material such as, for example, tungsten carbide.
  12. Method for operating a roller mill (10) for comminution of a granular material with a first grinding roller (12) and a second grinding roller (14), which are arranged opposite each other and can be driven in opposite directions, wherein a milling gap (16) is formed between the grinding rollers (12, 14) and
    wherein at least one of the grinding rollers (12, 14) has an edge element (18, 20) in an end region (22, 24, 26, 28) of a grinding roller (12, 24), which is designed such that it extends over the milling gap (16) and at least partly covers the end face of the opposite mill roller (12, 14),
    wherein a scraper element (42, 44) for at least partially removing material is arranged in the end region (22, 24, 26, 28) of the grinding roller (12, 14) provided with an edge element (18, 20),
    wherein the method at least comprises the step of:
    measuring a layer height of the material to be ground on at least one of the grinding rollers and/or measuring the load on the edge element and
    adjusting the distance between the scraper element (42, 44) and the grinding roller (12, 14) depending on the measured layer height and/or load.
  13. Method according to claim 12, wherein the distance is reduced when the measured layer height exceeds a predetermined limit.
  14. Method according to any of claims 12 and 13, wherein the distance is reduced when the load exceeds a predetermined limit.
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US11925942B2 (en) * 2021-10-22 2024-03-12 Metso Outotec USA Inc. Roller crusher and method for operating thereof
WO2023104294A1 (en) * 2021-12-07 2023-06-15 Indurad Gmbh Roller machine with a radar monitoring unit, radar monitoring unit for a i roller machine and a method hereto
US11938488B2 (en) 2021-12-09 2024-03-26 Metso Outotec USA Inc. Roller crusher and method for operation thereof

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CA3145149A1 (en) 2020-12-30
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PE20220325A1 (en) 2022-03-14
CL2021003506A1 (en) 2022-10-07
US20220250081A1 (en) 2022-08-11
BR112021026639A2 (en) 2022-03-03
ZA202200463B (en) 2022-10-26
FI3990189T3 (en) 2023-05-22
DE102019209514A1 (en) 2020-12-31
WO2020260307A1 (en) 2020-12-30
AU2020303222B2 (en) 2023-08-31
EP3990189A1 (en) 2022-05-04
CA3145149C (en) 2023-10-17

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