EP1809421A1

EP1809421A1 - Rolling mill

Info

Publication number: EP1809421A1
Application number: EP05777390A
Authority: EP
Inventors: Heinz Resch; Walter Almer
Original assignee: Buehler AG
Current assignee: Buehler AG
Priority date: 2004-10-26
Filing date: 2005-09-12
Publication date: 2007-07-25
Also published as: EP1818102A3; CN101048231A; ATE439189T1; DE102004052084A1; DE102004052084B4; EP1818101A2; CN101091930B; CN101091929A; DE502005007907D1; US20070245788A1; ES2330265T3; JP4804428B2; CA2585305A1; JP2008517746A; WO2006045206A1; US20070245793A1; BRPI0518381A2; JP2007301563A; US20070235575A1; EP1818102A2

Abstract

The rolling mill has at least two rolls (1,2,3) that are rotatably mounted about their longitudinal axes. The press device is used for pressing at least one roll (2) with the other roll (1,3) which is carried out by a mechanical pneumatic press device (4,5) comprising of a force converter (6) and a pneumatic drive (7). The rotational axis of the first roll (2) being mounted in a fixed manner and the rotational axis of the second roll (1,3) being displaceably mounted in addition to at least one press device.

Description

rolling mill

The invention relates to a rolling mill, in particular a three-roll mill, for Zer¬ kleinerung and homogenization of viscous masses, in particular for dispersion and uniform distribution in a binder suspended solid particles. Such a rolling mill has at least two rollers mounted so as to be rotatable about their longitudinal axes, wherein the axis of rotation of the first roller is mounted stationary and the axis of rotation of a second roller is movably mounted. With at least one pressing device, pressing of at least one roller takes place against the other.

Known devices for roller pressing are spindle drives or hydraulic pressing devices. A rolling mill with hydraulic roller pressing is known from EP 0 151 997 B1.

Spindle drives, especially if they are not manual but automatic, are a costly and voluminous form of roller pressing.

Although hydraulic drives represent a relatively compact form of roller pressing, hygienic sampling belts repeatedly emerge during operation due to escaping hydraulic fluid. This is a problem in particular when processing pastes for cosmetic, pharmaceutical or nutraceutical applications or for the processing of pasty materials under clean-room conditions.

The invention is therefore based on the object to provide a rolling mill of the above-mentioned n basic design, which allows an improvement in product quality and on the one hand the disadvantages of roller pressing by means of spindle drives and the disadvantages of roller pressing by hydraulic drives and on the other hand by besere sere Mahlarbeit product inhomogeneities and inadequate Avoids cooling. This object is achieved in the aforementioned rolling mill with the features of the patent claim, characterized in that a mechanical-pneumatic pressing device is used as the pressing device for roll pressing. This represents a cost-effective solution that meets the hygiene requirements.

Preferably, the mechanical-pneumatic pressing device has a force transducer acting on a movable journal bearing of the movable roller (s) and a pneumatic drive acting on the force transducer. This combination of pneumatic drive and force transducer is particularly cost-effective. The force transducer amplifies the force generated by the pneumatic drive. Thus, the high pressures necessary for the roll pressing can be readily applied with the pneumatic drive. At the same time, the force converter reduces the distance traveled by the pneumatic drive, so that a much smaller path is traveled during the roller pressing than at the pneumatic drive. Thus, at a given Accuracy speed of adjustment of the pneumatic drive over this much higher accuracy in the gap setting can be achieved. Thus, a high positioning accuracy of the movable roller (s) is obtained with relatively inexpensive means.

Expediently, the pressing device acting on the movable roller has on the one hand a first force transducer acting on a first movable axle bearing of the movably mounted roller and a first pneumatic actuator acting on the first force transducer and on the other hand a second acting on a second movable axle bearing of the movably mounted roller Force transducer and ei¬ nen acting on the second force transducer second pneumatic drive. This makes it possible to achieve a pressing of the at least one movably mounted roller at its two end points. This facilitates a correction of Walzienpressung at unsymmetrical wear of the rollers.

Alternatively, the pressing device may comprise a force transducer and a pneumatic drive acting on the force transducer, the force transducer acting on a fork device with two fork ends, the first fork end acting on a first movable axle bearing of the movably mounted roller and the second fork de acts on a second movable axle bearing of the movably mounted roller. Thereby, a pressing of the at least one movably mounted roller using only a pressing device for this roller is made possible.

As a force transducer, a lever device, in particular a toggle lever or an eccentric and combinations of lever and eccentric can be used. Alternatively, purely pneumatically operated force transducers may also be used, e.g. They have a large piston and a small piston, which communicate with one another, or a gear can be used as a force transducer.

In a particularly advantageous embodiment of the present invention, the rolling mill according to the invention is a so-called "triple whale" with three parallel rollers. The axis of rotation of the middle roller is fixedly mounted, while the axis of rotation of the front roller or feed roller and the axis of rotation of the rear roller or take-off roller are movable gel agert. For this purpose, it has a front mechanical-pneumatic pressing device for pressing the front roller against the central roller and a rear mechanical-pneumatic pressing device for pressing the rear roller against the central roller. Thus, there are two nips available. By adjusting the gap distance, the differential speed and the pressure in the respective gap, the operating conditions can thus be set independently for the two roller gaps.

The subtask of avoiding product inhomogeneities by z. B. undispersed oversized grain is achieved by a rolling mill with the features of claim 8. The back roll or take-off roll intended for product removal has a shorter axial process length than the middle roll and is axially disposed relative to the middle roll such that the ends of the process length of the center roll over both ends of the process length of the back roll and take-off roll, respectively protrude axially hin¬. This has the advantage that during operation of the rolling mill untranslated or only insufficiently rubbed, ie too coarse product does not pass from the middle roll to the rear roll or take-off roll. As a result of this measure, an improvement in product quality, ie a more uniform product fineness, can be achieved. Undefined effects are avoided. In a further solution to the problem, in particular the sub-task of improved Kühl¬ wi tion are in the rolling mill or three-roll mill a first plane, which is defined by the axis of rotation of the front roller or feed roller and by the axis of rotation of the mittle¬ Ren roller, and a second plane, which is defined by the axis of rotation of the central roller and by the axis of rotation of the rear roller or take-off roller, inclined at an angle between about 10 ° and a maximum of 90 ° to each other, in particular the first plane is horizontal, while the second Level obliquely upwards (in side view L-shaped arrangement of the rollers). Preferably, the angle is 30 ° to 60 ° and more preferably about 45 °. This ensures that the product present as a viscous mass with the solid particles (eg pigments) dispersed in it is cooled for a longer time during its passage through the rolling mill than in an arrangement in which the axes of rotation of the front, the middle and the rear roller lie in one plane.

Such an arrangement results in a longer residence time of the product on cool O berfläche the rollers.

The roll surfaces or process surfaces are preferably formed from a metal-free ceramic material, wherein the rolls preferably have a ceramic cylinder fitted onto a hollow metal cylinder. This eliminates any metallic contamination of the product during its comminution due to roll rubbing. This is particularly important in the processing of pastes for applications in electronics and for the manufacture of insulator bodies based on fine ceramics.

Conveniently, the rollers are cooled from the inside. This is e.g. important in the processing of organic pigments, in particular in some yellow pigments.

Preferably, both the front roller and the rear roller are pressed by means of a mechanical-pneumatic pressing device against the middle roller. This allows adjustment of the front and rear nip. Vor¬ preferably, the mechanical-pneumatic pressing device on a scheme for gap adjustment. Since the force transducer, as explained above, a "force transmission tion "and a" Weguntersetzung "allows the relatively weak force of a pneumatic for the purpose of roll pressing can be multiplied and at the same time the specified by the pneumatic accuracy for the gap setting wer¬ greatly increased.

Expediently, a scraper is applied to the take-off roll, over which the comminuted homogenized mass is stripped off, the scraper also preferably consisting of a metal-free material, in particular of a ceramic material or of a polymer material. As a result, any metallic contamination of the product during its stripping from the take-off roll due to Ab¬ scraper abrasion is excluded.

Preferably, at least the catchment area of the rolling mill is covered by a hood. This prevents unwanted impurities from entering the product from the factory floor and, conversely, prevents unwanted volatile product constituents from escaping into the factory hall. One thus improves on the one hand the "product hygiene" and on the other hand the "workplace hygiene".

Preferably, the space under the hood is connected to a gas vent. Da¬ by z. B. contained in the solvent of the product volatile substances are kept away from the air of a factory hall.

Further advantages, features and possible applications of the invention will become apparent from the following description of non-restrictive embodiments of the invention, in which:

Fig. 1 is a schematic side view of a first embodiment of the rolling mill according to the invention;

Fig. 2 is a plan view of the rollers of the first embodiment in Fig. 1;

FIG. 3 is a schematic side view corresponding to FIG. 1 of a second exemplary embodiment; FIG. and FIG. 4 is a plan view of the rollers of the second embodiment in FIG. 3. FIG.

A first embodiment of the rolling mill according to the invention is shown in FIG. 1 and in FIG. 2. The three-roll mill shown here contains three rollers 1, 2, 3, which are aligned parallel to each other and all arranged in a plane E. In other words, the axis of rotation A1 of the front roller 1, the axis of rotation A2 of the central roller 2 and the axis of rotation A3 of the rear roller 3 are parallel to one another (see FIG. 2) and are all in one and the same plane E. I n der Operating position, the front roller 1 and the rear roller 3 are pressed by means of a front pressing device 4 and by means of a rear pressing device 5 respectively against the central roller 2, whose axis of rotation A2 is mounted stationary. The front roller 1 and the rear roller 3 are movably supported, i. their axes of rotation A1 and A3 can be pivoted about a pivot axis D3. The lateral surfaces of the rolls 1, 2, 3 each represent the rolling process surface S1, S2, S3, which come into contact with the product to be processed. Between the process surface S1 of the front roller 1 and the process surface S2 of the middle roller 2, a nip is formed during operation by the product passing between the rollers 1 and 2 pressed against each other. Likewise, a nip is formed between the process surface S3 of the rear roller 3 and the process surface S2 of the middle roller 2 during operation by the product passing between the rollers 2 and 3 pressed against each other.

The front pressing device 4 and the rear pressing device 5 each have a force converter 6 and a pneumatic drive T. In the first embodiment shown in Fig. 1, the force transducer is a toggle 6, which is formed of a first lever 6A and a second lever 6B, while the pneumatic actuator 7 is formed by a pneumatic cylinder 7A and a Pneurnatikkolben. The power flow of the pressing devices 4 and 5 is based on the mounted in the pneumatic cylinder 7A pneumatic piston 7B, which is articulated via a piston rod 7B with the first lever 6A on a hinge axis D1. The first lever 6A is articulated on a second Gelenk¬ axis D2 on the second lever 6B, which in turn is articulated to a pivot axis D3 and each forms a pivotable suspension and mounting of vor¬ their roller 1 and the rear roller 3. Depending on the dimensioning and orientation of the levers 6A and 6B, the toggle lever 6A, 6B serving as force converter 6 and roller suspension causes an increase in the pneumatic force of the pneumatic drive 7 by a factor of about 20 to 50, where this increased force is used for roller pressing , As a result, a sufficiently strong roller pressing is also possible with a pneumatic drive 7. On the other hand, this force converter 6 causes a reduction in the stroke traveled by the pneumatic drive 7 by a factor of approximately 1/50 to 1/20, wherein this reduced stroke is used for adjusting the gap.

The rollers 1, 2 and 3 are driven by the motor M by gears (not shown). The roller block 1, 2, 3 and the engine block M are surrounded by a housing G.

FIG. 2 is a plan view of the rollers 1, 2, 3 of the first exemplary embodiment of the rolling mill according to the invention shown in FIG. 1. It can be seen that the front roller or feed roller 1 and the middle roller 2 both have the same process length L1 = L2, while the rear roller or removal roller 3 has a significantly shorter process length L3 <L2 in order to avoid undefined edge effects. The rear roller 3 is arranged axially with respect to the middle roller 2 such that the ends of the process length L2 of the middle roller 2 project axially beyond the ends of the process length L3 of the rear roller 3 on both sides. This ensures that, during operation of the three-roll mill, unrestrained or only insufficiently rubbed product does not reach the rear roller 3 from the middle roller 2, as a result of which a significant improvement in product quality can be achieved.

A second embodiment of the rolling mill according to the invention is shown in FIG. 3 and in FIG. 4.

All of the elements of the second exemplary embodiment shown in FIGS. 3 and 4, which are identical or correspond to the elements of the first embodiment shown in FIG. 1 and in FIG. 2, carry the reference numbers of the corresponding element supplemented by a dash from Fig. 1 or Fig. 2. The explanation of the func- on these elements of the second embodiment is not repeated here. Moreover, the front pressing device 4 'and the rear pressing device 5' are indicated only schematically with their respective force converter 6 ¹ and pneumatic drive 7 '.

The other reference symbols in FIG. 3 and in FIG. 4, which show elements of the second exemplary embodiment deviating from the first exemplary embodiment, have no line. Their function and meaning are explained below.

The essential difference between the first embodiment (Fig. 1 and Fig. 2) and the second embodiment (Fig. 3 and Fig. 4) is that the three-roll mill shown here comprises three rollers 1 ', 2', 3 'which Although aligned parallel to each other, but not all are arranged in one and the same plane. Rather, the axis of rotation A1 ^{1 of} the front roller V and the axis of rotation A2 'of the central roller 2' are arranged in a first plane E1, while the axis of rotation A3 'of the rear roller 3' and the axis of rotation A2 'of the central roller 2' in a second Plane E2 are arranged, which forms an angle γ of about -45 ° to the first plane E1. This arrangement of the three rolls 1 ', 2', 3 "allows the present as a viscous mass product with the dispersed solid particles (eg pigments) during its passage through the rolling mill can be cooled longer and thus stronger than an Anord¬ tion, in which the axes of rotation of the front, the middle and the rear roller lie in a plane.

4 is a plan view of the rollers 1 ', 2', 3 "of the second embodiment of the rolling mill shown in FIG. 3. Again, the front roller or feed roller 1" and the middle roller 2 'both have the same Process length L1 '= L2', while the rear roller or take-off roll 3 'has a much shorter process length L3'<L2'. The rear roller 3 'is likewise arranged axially with respect to the middle roller 2' such that the ends of the process length L2 'of the middle roller 2' extend axially beyond the ends of the process length L3 ^{1 of} the rear roller 3 'on both sides. As already explained , is ensured by the fact that during operation of the three-roller mill no unrestrained or only inadequately rubbed product passes from the middle roller 2 'to the rear roller 3', whereby the product quality is improved. The path traveled by the product as it passes through the rolling mill according to the second embodiment is increased by the two additional circular arc lengths on the surfaces S2 ¹ and S3 'of the rollers 2' and 3 'having a radius R which extends through give the angle γ between the plane E1 and the plane E2, ie an additional way towards the first embodiment (FIG. 1) by 2 × γ × R.

A hopper or product trough 8 with Aufsetzkeilen extending on both sides of the catchment area, is disposed over the region of the intake nip between the vor¬ their roll V and the middle roll 2 '. This product trough increases with its addition to the usual wedge seals provided Aufsetzkeilen the tightness and thus ensures a lower lateral product loss.

A scraper 9 with a scraper blade is used to remove the product from the rear roller 3 '. The scraper 9 is equipped with an automatic knife adjustment, which is controlled by a PLC control.

Both in the first and in the second exemplary embodiment, the roller surfaces or roller process surfaces S1, S2, S3 or S1 ', S2', S3 'can consist of ceramic material. The scraper 9 shown in Fig. 3 may also be made of ceramic material or of polymer material. These or other metal-free materials for the roller process surfaces and the stripper blade are of particular interest for the processing of pastes for the electronics industry.

The ceramic rolls are rounded at the end of the roll process length.

The pneumatic drive 7 operates, for example, with pressures of up to 4 bar, which come by means of Kraft¬ converter 6 to the required line pressures in the nips. The force transducer 6 makes it possible to increase the pressing force acting on the rollers by the rolling press devices 4, 5 by a factor of about 10 to about 80. Accordingly, by reducing the stroke provided by the pneumatic drive 7 by means of the force transducer, the accuracy of the gap adjustment becomes the same Factor increased. The rollers have a diameter of 300 mm and the rear roller 3, 3 'i st by about 4 mm to 5 mm shorter than the middle roller 2, 2'. This ensures that the wiper 9 strips only rubbed product from the rear roller 3 '.

reference numeral

1, V front roller / feed roller R radius

2, 2 'roller with fixed axis of rotation / A3, A3 ¹ axis of rotation middle roller D1. D1 'articulated axle

3, 3 'rear roller / take-off roller D2, D2 ¹ Joint axis

4, 4 'front pressing device D3, D3 ¹ pivot axis

5, 5 'rear pressing device E, E1 first level

6, 6 'force transducer E2 second level

6A, 6B first lever, second lever G ₁ G 'housing

7A pneumatic cylinder L1, L1 ¹ roll process length

7B piston rod L2, L2 'roller process length

7, 7 'Pneumatic drive L3, L3 ¹ roller process length

8 feed funnels M, M 'engine

9 scrapers S1. S1 ¹ roll process surface

A1, A1 'rotation axis S2, S2' roller process surface

A2, A2 'rotation axis S3, S3' roller process surface

Y angle

Claims

Patentans praise

1. rolling mill for comminution and homogra tion of viscous masses, insbesonde¬ re for dispersing and uniform distribution in a binder suspen¬ dierter solid particles, with at least two rotatable about their longitudinal axes gela¬ siege rollers (1, 2, 3), wherein the axis of rotation of a first roller (2) is stationary gela¬ siege and the axis of rotation of a second roller (1, 3) is movably mounted, and with at least one pressing device [A, 5) for pressing at least one roller (1, 3) against the other Roller (2), characterized in that the pressing device (4, 5) is a mechanical-pneumatic pressing device.

2. Rolling mill according to claim 1, characterized in that the pressing device (4, 5) has a force acting on a movable journal bearing of the movable roller force transducer (6) and a force acting on the force transducer pneumatic drive (7).

3. Rolling mill according to claim 2, characterized in that the force applied to the movably mounted roller pressing device (4, 5) on a first bewegli¬ Ches axle bearings of the movably mounted n roller (1, 3) acting first Kraft¬ converter (6 ) and a first pneumatic actuator (7) acting on the first force transducer, and a second force transducer (6) acting on a second movable journal bearing of the movably mounted roller (1, 3) and a second pneumatic actuator acting on the second force transducer ( 7).

4. rolling mill according to claim 2, characterized in that the pressing device (4, 5) a force transducer (6) and a force acting on the force transducer Pneu¬ matic drive (7), wherein the force transducer acts on a fork device with two fork ends, wherein the the first fork end acts on a first movable axle bearing of the movably supported teeth (1, 3) and the second On a second movable axle bearing of the movably mounted roller (1, 3) acts.

5. Rolling mill according to one of claims 2 to 4, characterized in that the force converter (6) is a lever device (6A, 6B), in particular a toggle lever or an eccentric.

6. Rolling mill according to one of claims 1 to 5, characterized in that it is a three-roll mill with three parallel juxtaposed rollers (1, 2, 3), wherein the axis of rotation (A2) of the central roller (2) is mounted stationary and the axis of rotation (A1) the front roller or feed roller (1) intended for the product feed and the rotation axis (A3) of the rear roller or take-off roller (3) intended for the product removal are movably mounted, and that there is a front mechanical-pneumatic press device (4) for pressing the front roller

(1) against the middle roll (2) and a rear mechanical-pneumatic pressing device (5) for pressing the back roll (3) against the middle roll

(2).

7. Rolling mill according to claim 6, characterized in that the front roller (1) are pressed via their two axle bearings and the rear roller (3) via their two axle bearings against the central roller (2).

8. Rolling mill for comminuting and homogenizing viscous masses, in particular for dispersing and uniform distribution in a binder suspen¬ dierter solid particles, with at least two rotatable about its longitudinal axes gela¬ siege rolls (1, 2, 3), wherein the axis of rotation of a first Roller (2) is fixed gela¬ siege and the axis of rotation of a second roller (1, 3) is movably mounted, and with at least one pressing device (4, 5) for pressing at least one roller (1, 3) against the other roller (2), characterized in that the rear roller or the removal roller (3) intended for the product removal has a shorter axial process length (L3) than the process length (L2) of the middle roller> (2) and with respect to the middle roller (2) is arranged axially such that the ends the process length (L2) of the middle roll (2) projects axially beyond the ends of the process length (L3) of the rear roll or take-off roll (3) on both sides.

9. Rolling mill for comminuting and homogenizing viscous masses, in particular for dispersing and uniform distribution in a binder suspen¬ dierter solid particles, with at least two rotatable about its longitudinal axes gela¬ siege rolls (1, 2, 3), wherein the axis of rotation of a first Roller (2) is fixed gela¬ siege and the axis of rotation of a second roller (1, 3) is movably mounted, and with at least one pressing device (4, 5) zürn pressing at least one roller (1, 3) against the other roller (2), characterized in that a first plane (E1), which by the axis of rotation (A1 ') of the front roller or Aufga¬ roller (1') and by the axis of rotation (A2 ¹ ) of the middle roller (2 ') is defined, and a second plane (E2) which is defined by the axis of rotation (A2 ¹ ) of the central roller (2 ') and by the axis of rotation (A3 ¹ ) of the rear roller or take-off roller (3) Angles between 10 ° and 90 ° are inclined to each other.

10. Rolling mill according to one of claims 1 to 8, characterized in that it is designed as a three-roll mill and the rollers are arranged in side view L-shaped ange¬.

11. Rolling mill according to claim 9, characterized in that the first plane (E1) extends horizontally, while the second plane (E2) extends obliquely upwards.

12. Rolling mill according to one of claims 1 to 11, characterized in that the roll surfaces or process surfaces (S1, S2, S3) are formed from a metal-free Ke¬ ramikmaterial.

13. Rolling mill according to one of claims 1 to 12, characterized in that the rollers (1, 2, 3) have a cylinder fitted on a hollow cylindrical cylinder Keramikzy¬.

14. Rolling mill according to one of claims 1 to 13, characterized in that the rollers (1, 2, 3) are cooled from the inside.

15. Rolling mill according to one of claims 1 to 14, characterized in that the mechanical-pneumatic pressing device (4, 5) has a control for Spaltinstel¬ ment.

16. Rolling mill according to claim 8, characterized in that the rear roller (3) is 2 mm to 10 mm, preferably 3 mm to 6 mm shorter.

17. Rolling mill according to claim 9, characterized in that the angle (y) vor¬ preferably 30 ° to 60 ° and particularly preferably 45 °.