Patent Application
20240109073
The present invention describes a rotor part of an impact mill, which has a plurality of rotor tool blades that can be detachably attached to a blade attachment plate, wherein each rotor tool blade can be detachably attached to an allocated blade position with a blade holder, and the entire rotor part is rotatably mounted around a longitudinal axis by means of a rotor part attachment sleeve attached to a drive in an impact mill housing at a defined radial distance to a stator part with a plurality of stator tools, and a method for adjusting the distance between a rotor tool blade detachably attached to a blade attachment plate of a rotor part of an impact mill relative to a stator part fixedly arranged on an inner surface of an impact mill housing or its stator tools.
Impact mills or rotor mills have long been known, and are becoming increasingly important during the treatment of used materials for their recycling. Such impact mills are used for comminuting soft, medium-hard and fibrous, brittle materials. The applicant wanted to develop an impact mill that can also be specially used for the posttreatment and entanglement of anode and cathode material from Li-ion battery recycling. The input material is fed into the impact mill from above, and moved inside of an impact mill housing between a stator part and a rotor part. As the rotor part with its rotor tools rotates along the rigid stator part with correspondingly fixed stator tools, high impact forces act on the material, the adhering black mass is detached in the process, and the anode and cathode material is simultaneously comminuted, taking the form of spheres. The material is here pneumatically conveyed through the impact mill. Rotor parts usually range in diameter between one and two meters, the number of rotors ranges between 10 and 30, and rotor speeds of 40 to 100 m/s are reached, wherein rotors with counterclockwise and clockwise rotation are preferred.
Known from EP1960108 is an insertable impact mill with an impact mill housing, wherein a stator part is arranged locally fixed on the impact mill housing, and at least one rotatable rotor part with rotor tool blades is moved at a defined distance relative to the stator part. The rotor tool blades were detachably attached to a blade attachment plate, wherein above all a simplified replacement of individual rotor tool blades was achieved. The individual rotor tool blades were positively held above and below the blade attachment plate by tool holding brackets. Accordingly, rotor tool blades tailored to the two tool holding brackets had to be manufactured, and were thus manufactured with as little wear as possible out of high strength steel. The tool holding bracket was optimized for attaching the rotor tool blade to the blade attachment plate as easily as possible. As a whole, replacing rotor tool blades is cumbersome, and given the elevated number of individual components often leads to problems or must be done extremely carefully. The same also holds true for a potentially desired dislocation of the rotor tool blade in a radially outward direction.
Therefore, even though impact mills and rotor parts with reusable and replaceable rotor tool blades are known, the convenience of rotor tool blade replacement and a distance adjustment relative to the stator part 3 are disadvantageous and time-consuming.
Finally, the user friendliness is not good, and the impact mill is anything but easy to maintain.
One aspect of the present invention relates to further developing an impact mill or a rotor part of an impact mill, so as to achieve an enhanced operating comfort. The replacement of rotor tool blades, but also the easy and quick adjustment of the distance of the rotor tool blades relative to the stator tools of the stator part, lead to an enormously enhanced user friendliness. In comparison to the replaceable rotor tool blades known from prior art, a quick adjustment is here achieved, and an unintended incorrect setting in practice is also avoided in the process.
The distance adjustment method is also disclosed herein.
Variations in feature combinations or slight adjustments of the invention can be found in the detailed description, are shown on the figures, and are incorporated into the claims.
A preferred exemplary embodiment of the inventive subject matter is described below in conjunction with the attached drawings in the detailed description.
Additional features, details and advantages of the invention can likewise be gleaned from the following description of slightly modified embodiments of the invention, which in part are made clear to the expert solely from the drawings. Shown on:
An impact mill 0 is described, which has an impact mill housing 1 with an essentially cylindrical impact mill housing wall 10 and a corresponding inner surface 11. A stator part 3 of the impact mill 0 is arranged along the inner surface 11 and can have a plurality of stator tools 30, which can have varying dimensions and, in known embodiment types, are arranged directly or indirectly attached to the inner surface 11 from outside or inside.
Necessary components, such as a drive unit with at least one motor and electronics for controlling and monitoring the impact mill, are not shown here and not described in any more detail, since these components are known to the expert. The shape of a drive shaft, mounting of the drive shaft, number of rotor parts and detailed design of the stator part 3 are here of no further interest for the inventive idea, and can be designed in different versions.
A rotor part 2 rotatably mounted around a longitudinal axis L in the impact mill housing 1 is here particularly interesting. The rotor part 2 has a blade attachment plate 21, a rotor part attachment sleeve 22 and a plurality of rotor tool blades 23 attached thereto. The blade attachment plate 21 is also referred to as a star plate, because the radially outwardly protruding rotor tool blades 23 create the shape of a multiarmed star.
During the rotation of the rotor part 2 or the blade attachment plate 21 with all components attached thereto, grinding material can be comminuted in the space between stator tools 30 fixed between rotor tool blades 23.
The rotor part 2 shown on
The blade holder is here exemplarily designed as a blade holding plate 25. The latter ensures that the rotor tool blade 23 in which the spacer 24 is inserted cannot wander toward the top. Each rotor tool blade 23 is detachably held on the blade attachment plate 21 secured against rotation with one blade holding plate 25 per rotor tool blade 23. The gap or slit as the blade holding recess 210 in the front part of the blade attachment plate 21 ensures the tilting away or rotation from the rotor tool blade 23. For example, the rotor tool blade 23 is 15 mm thick, and the blade holding recess 210 is 15.5 mm wide. If the blade holding plate 25 is selected as the blade holder, it can be secured by used blade holder attachment means 26. This results in a simple, detachable connection of the rotor tool blade 23 to the blade attachment plate 21. The blade holder attachment means 26 do not necessarily have to be removed or detached to enable a linear displacement of the blade holding plate 25. A sufficient stability and holding of the rotor tool blade 23 is ensured nonetheless. The blade attachment plate 21 is freely movable and, if an attachment was forgotten about, is outwardly displaced while turning up, and hence rotating, the rotor part 2.
However, instead of using the blade holding plate 25, it would also be possible to directly screw the rotor tool blade 23 to the blade attachment plate 21 with a screw, the screw head of which protrudes at least partially over the spacer 24. The blade holder would then be at least one screw, the head of which upwardly secures the spacer 24 directly via the screw head, which protrudes at least partially over the spacer 24. While this would eliminate the need for the blade holding plate 25, corresponding screws and threaded holes or lock nuts would have to be provided. However, the technical effect would be the same, with the detachability of the rotor tool blade 23 with spacer 24 being more complicated.
The blade attachment plate 21 is attached to the rotor attachment sleeve 22 using sleeve attachment means 27, usually in the form of screws, nuts, and washers. Since operation involves exposure to enormous centrifugal forces and high radial accelerations, the fixation of the rotor tool blade 23 and naturally the blade attachment plate 21 must be ensured.
The sectional view on
However, the configuration of the components blade attachment plate 21, rotor tool blade 23 and blade holding plate 25 will first be briefly described.
An oblong blade holding recess 210 and a round plate spacer recess 212 are provided in the blade attachment plate 21 at the location of each rotor tool blade 23, i.e., each blade position. The spacer 24 also has a round design, and can be passed through the plate spacer recess 212 parallel to the longitudinal axis L.
In optimized embodiments, the plate spacer recess 212 is provided with a positioning protrusion 2121 and/or with a recess impact bead 2122. The oblong blade holding recess 210 is used to receive the portion of the rotor tool blade 23. In order for the spacer 24 to be effectively connectable with the rotor tool blade 23, each rotor tool blade 23 is arranged [on] a spacer recess 230 recessed on its side oriented to the longitudinal axis L. The spacer 24 can be laterally introduced into the spacer recess 230, and then be inserted into the oblong blade holding recess 210 with the rotor tool blade 23, which here takes place from above the blade attachment plate 21.
A recess impact bead 2122 is arranged on the plate spacer recess 212 along a lower edge lying opposite the introduction side of the rotor tool blade 23. This recess impact bead 2122 protrudes toward the center of the plate spacer recess 212, so that the spacer 24 cannot slide downwardly through the blade attachment plate 21 or the plate spacer recess 212.
As an option, a bead receptacle 2123 can also be arranged at the upper edge of the plate spacer recess 212, which is favorable depending on the design of the spacer 24.
The recess impact bead 2122 and the bead receptacle 2123 are here designed as an option or additional feature, so that the spacer 24 does not fall through downwardly. At least the configuration of a continuous impact bead 242 on the edge of the spacer 24 has become established in practice, as evident on
The blade holder is designed as a blade holding plate 251, which here has a blade receiving recess 251, thereby yielding a forked shape. The width of the blade receiving recess 251 is slightly larger than the width of the side of the rotor tool blade 23 to be introduced, so that the blade holding plate 25 can be displaced parallel to the blade attachment plate 21 radially toward the rotor tool blade 23 with the rotor tool blade 23 inserted into the blade holding recess 210 or given a free blade holding recess 210. This procedural step is marked I on
If the blade holding plate 25 according to step I has been radially displaced toward the center of the blade attachment plate 21, the rotor tool blade 23 with the spacer 24 introduced into the spacer recess 230 can be pulled out upwardly, parallel to the longitudinal axis L in a step II.
In this way, rotor tool blades 23 can be easily and quickly exchanged and replaced, with only the two steps I and II being required.
In practice, however, the rotor tool blade 23 should not be completely replaced so as to save on resources. The rotor tools 23 should be used multiple times, and only replaced once completely worn. Enormous importance is today attached to the optimized use of the rotor tool blades 23, and hence to a reduction in wear costs. Setting the gap between the rotor part 2 and stator tools is essential to the actual process. The gap has a very strong influence on the quality of disintegration, entanglement, and comminution. The narrower it is, the better the quality and fineness of the product, with the wear, energy demand, and process warmth in turn increasing, and the throughput decreasing. In order to solve this problem, attachment by means of a spacer 24 might also prove useful. The aim is thus to have a variable adjustment of the distance between the plurality of rotor tool blades 23, which are detachably attached to the blade attachment plate 21 of the rotor part 2, relative to the plurality of stator tools 30, which are arranged on the inner surface 11 of the impact mill housing 1.
The spacer 24 here has several recesses 240 along its circumference that are recessed so as to cross parallel to the longitudinal axis of the spacer 24. These recesses 240 have varying depths, wherein a depth is understood as the distance between the circumference and end of the recess 240 toward the center of the recess 240. Specifically shown on
The spacer 24 could also be designed with more or less than four recesses 240 in spacer 24, each with varying depths of the recesses 240.
As evident from the partial sectional view on
As denoted by a double arrow, the rotor tool blade 23 can be held by means of the spacer 24 in the spacer recess 230 in the plate spacer recess 212 of the blade attachment plate 21, and the distance between the tip of the rotor tool blade 23 and the stator tool 30 can even be varied.
As evident on
Method for Distance Adjustment
If the tip of the rotor tool blade 23 facing the stator part 3 is worn, the distance of the rotor tool blade 23 relative to the stator part 3 can be varied as follows.
The blade holding plate 25 is first detached if the blade holding plate 25 was attached, wherein this step can otherwise be skipped, and linearly pushed away from the blade holding recess 210 and the spacer recess 230 toward the center of the blade attachment plate 21, according to procedural step I.
The rotor tool blade 23 together with the spacer 24 inserted into the spacer recess 230 is now pulled out toward the top, parallel to the longitudinal axis L in step II, as readily visible on
In order to now achieve a varied distance from the stator part 3 during the reinstallation of the same rotor tool blade 23, the spacer 24 is rotated around its longitudinal axis in a third step III, until a recess 240 different than before lies in the spacer recess 230, facing the tip of the rotor tool blade 23. This is denoted by the dashed double arrow on
The distance adjustment process can be repeatedly performed with a rotor tool blade 23 before a replacement comes due. This distance adjustment is comparatively quick and easy. The rotor tool blade 23 is indirectly held in the blade holding recess 210 and plate spacer recess 212 detachably and positively by means of the spacer (24) and the blade holder attachment means 26.
In our case, three such rotor parts 2 form the rotor in three planes. The planes can be mounted in line or offset, which influences the duration in which the material passes from the top down. If the material remains in the mill longer, disintegration improves, and throughput decreases.
We regard as ideal the rotor height that arises with three planes comprised of rotor parts 2. We can adjust the rotor tools to the disintegration/comminution process in the three planes accordingly, i.e., reduce the gap between the rotor part 2 and stator part 3 from the top down. As a rule, different planes with mounted rotor tool blades 23 are set to different gap dimensions, with the rotor tool blades 23 in the uppermost plane being set to a largest gap, wherein the setting is determined by the size and type of input material. The further down the material passes in the impact mill 0, the more it becomes entangled/comminuted. The gaps in the lower planes are thus set at increasingly narrower dimensions.
| Number | Date | Country | Kind |
|---|---|---|---|
| 001122/2022 | Sep 2022 | CH | national |
