Patent Publication Number: US-10758911-B2

Title: Processing device, and processing element and wall lining element for a processing device of this kind

Description:
The invention relates to a processing device for processing material to be processed, comprising a stationary housing having a feed opening for feeding material to be processed, and a rotor that is arranged in the stationary housing so as to be rotatable about a substantially vertical rotor axis, the outer circumference of a base element of the rotor being fastened to the base element so as to be adjacent to a plurality of bearing pins, on each of which bearing pins a processing element is mounted, and the radially outer ends of the processing elements, together with an inner circumferential wall of the stationary housing, forming a processing gap. 
     Processing devices of this kind are marketed by the applicant under the designation “RPM rotor impact mill” or “RPMV rotor impact mill” for example. While the RPM rotor impact mill is suitable for crushing substances that have a low or average degree of abrasiveness, in particular mineral substances, and is used in particular for producing sands for any application, for example for the concrete, asphalt and dry mortar industry, and for grinding fertiliser, the RPMV rotor impact mill is used in the recycling industry for example, since composite material can be crushed and separated thereby, it being possible for tangles of material to be separated out and for metals to be rolled into balls and purified. 
     The processing device according to the invention is also intended for these types of material processing. 
     Both the RPM rotor impact mill and the RPMV rotor impact mill have been found to be excellent in practice. Nonetheless, it is desirable to further improve said processing devices, in particular with the aim of more sophisticated material processing. 
     The object of the present invention is therefore that of providing a processing device of the type mentioned at the outset, by means of which an improved processing result can be achieved. 
     This object is achieved according to the invention by a processing device of the type mentioned at the outset, in which the free ends of the bearing pins are interconnected by means of a connecting plate. 
     As a result of the connecting plate provided according to the invention, the forces occurring during material processing can be better distributed over the entire rotor, i.e. the base element, the bearing pins fastened thereto and the processing elements mounted thereon. This makes it possible to operate the rotor at a higher speed, which in turn leads to an improved processing result. 
     In order to prevent an excessive increase in the weight of the rotor, it is proposed for the connecting plate to be formed as a ring wheel. This embodiment has been found to be entirely sufficient in tests. Specifically, the forces occurring during the material processing are introduced into the bearing pins mainly in the circumferential direction of the rotor by the processing elements, and therefore mutual support of the bearing pins in the circumferential direction of the rotor is also sufficient for achieving the desired effect. 
     The inner circumferential wall of the stationary housing can be protected at least in part, preferably at least at the height of the processing elements, by wall lining elements which, together with the radially outer ends of the processing elements, form the processing gap. 
     In order to be able to further improve the processing result, it is proposed for the wall lining elements to be immovably connected, for example screwed, to the inner circumferential wall of the stationary housing. Changes in the width of the processing gap caused by movements of the wall lining elements relative to the inner circumferential wall of the stationary housing can thus be reduced, if not entirely prevented. This also contributes to a homogenisation, and thus an improvement, of the processing result. 
     Just as in the RPM and RPMV rotor impact mills, it is advantageous in the processing device according to the invention, too, for at least one wall lining element to comprise a plurality of substantially vertical ribs at least over a portion of the height extension of the processing elements, preferably over the entire height extension thereof. These ribs can increase the stress on the material to be processed, and thus improve the processing result. 
     Moreover, as is already the case in the RPM and RPMV rotor impact mills, it is advantageous in the processing device according to the invention, too, for the processing elements to be U-shaped, the free ends of the U-shape forming the radially outer ends of the relevant processing element, and the central portion of the U-shape of the processing elements being held, from the inside in the radial direction, on the associated bearing pin only by means of the centrifugal forces occurring during operation, such that, if necessary, said elements can escape freely, radially towards the inside, from processing forces acting on said elements from the processing gap. 
     In order to be able to further improve the processing result, it is proposed for a wedge-shaped projection to be provided on the inside of the U-shape of the processing element, which projection engages in a wedge-shaped recess in the bearing pin that is formed so as to correspond to the wedge-shaped projection, or on an adapter element mounted on the bearing pin. The cooperation of the wedge surfaces of the wedge-shaped projection with the wedge surfaces of the wedge-shaped recess corresponding thereto makes it more difficult for the processing element to tilt about a substantially vertical axis, which tilting results in one radially outer end of the processing element approaching the inner circumferential wall of the stationary housing and the other radially outer end of said element moving further away from the inner circumferential wall, and thus a change in the width of the processing gap. This stabilisation of the mounting of the processing element also contributes to a homogenisation, and thus an improvement, of the processing result. 
     The opening angle of the wedge can be between approximately 120° and 140°, preferably approximately 130°. 
     In a development of the embodiment of the processing elements, it is proposed for two portions of the processing element that are adjacent to, preferably directly connected to, the radially outer ends of the processing element to extend so as to be substantially mutually parallel. Therefore, the spacing of the two radially outer ends does not change, even in the event of wear on the processing element. 
     The above-mentioned tilting of the processing element about a substantially vertical axis can furthermore be impeded by means of the inner surfaces of the substantially mutually parallel portions to be in contact with likewise substantially mutually parallel side faces of the bearing pin. The processing element can thus be guided substantially in the radial direction over a length of at least 35 mm, preferably at least 50 mm. 
     Impeding the tilting of the processing element about a substantially vertical axis, mentioned above, can also reduce the risk of the processing element detaching from the bearing pin thereof during operation and damaging the processing device. 
     Furthermore, a plurality of adapter elements can be provided, which elements differ from one another in terms of the spacing between the wedge tips of the wedge of the wedge-shaped recess facing the processing element and the wedge-shaped projection facing the bearing pin. The adapter element suitable for the application in question can in each case be selected from this set of adapter elements. Moreover, a wear-induced change in the length of the processing element can be compensated thereby. In conjunction with the substantially parallel course of the portions of the processing element adjacent to the radially outer ends of the processing element, the processing ratios in the processing gap can additionally be kept at least approximately constant, even in the event of wear of the processing element. The above-mentioned spacing can vary for example in steps of a few millimetres, for example in 4 mm steps. 
     It should also be mentioned, with regard to the processing elements, that the symmetry of the U-shape thereof makes it possible to ensure uniform wear of the radially outer ends of the processing elements by reversing the direction of rotation of the rotor. 
     It is also possible for at least one processing element to be designed so as to be symmetrical with respect to a horizontal plane. This further symmetry makes it possible to invert the processing elements in the height direction when servicing the processing device, in order to thus ensure uniform wear of the processing elements. Preferably all of the processing elements have this symmetry. 
     According to a first alternative development of the processing device according to the invention, a preferably conical distribution element may be arranged on the base element of the rotor, which distribution element diverts material to be processed, which material is fed in substantially vertically, in a substantially radial direction relative to the substantially vertical rotor axis. 
     Upon striking the rotor, the material to be processed is accelerated outwards by means of centrifugal forces, captured by the processing elements, and slung against the inner circumferential wall of the stationary housing. Crushing takes place here by means of impact and shearing. The material rebounding from the inner circumferential wall of the stationary housing is again captured by the processing elements, in the process is crushed by further striking, and slung back against the inner circumferential wall of the stationary housing. This process is carried out several times and causes intensive, repeated stress on the material to be processed. The processed material leaves the rotor through an outlet gap between the rotor and the inner circumferential wall of the stationary housing, below the processing gap. 
     However, according to a second alternative development of the processing device according to the invention, it is also possible for the material to be processed that is fed in substantially vertically to be fed to the upper surface of the connecting plate or of an element connected thereto. 
     Upon striking the upper surface of the connecting plate or of the element connected thereto, the material to be processed is uniformly distributed over said upper surface and accelerated radially outwards by means of centrifugal forces. There, said material passes through an inlet gap between the inner circumferential wall of the stationary housing and the connecting plate or the element connected thereto, and enters the processing gap between the processing elements and the inner circumferential wall of the stationary housing. When passing through the processing gap, the material to be processed is exposed to impact, tensile, compressive and shearing stresses, as a result of which bonds are broken, brittle components crushed, and ductile components deformed, in particular rolled into balls. A particular advantage that should be noted is that, in this second alternative development, the entire height of the processing gap can be used for processing the material to be processed. 
     In this second alternative embodiment, in order to be able to protect the inner circumferential wall from excessive wear even above the rotor, i.e. where the material to be processed strikes the inner circumferential wall, it is proposed for at least one wall lining element to comprise a first portion that is designed and intended to extend substantially above the upper edge of the processing elements during operation of the processing device, and a second portion that is designed and intended to extend beyond the rotor by a specified height during operation of the processing device. Preferably all the wall lining elements are designed in this manner. 
     It should furthermore be noted that wall lining elements developed in this way can also be used in the first alternative embodiment. It is therefore possible to convert the processing device according to the invention between the first and second alternative developments. 
     In a development of the wall lining element, it is proposed for at least one substantially vertical rib, which is provided in the first portion, to extend into the second portion, and preferably to extend over the entire height of the second portion. The at least one rib extending into the second portion functions as an obstacle that is intended to brake material to be processed that has also gained a speed component in the circumferential direction during the radially outward acceleration, in order to make it easier for said material to enter the processing gap. 
     It is furthermore proposed for at least one substantially vertical rib that is provided in the first portion to end at a position which, during operation of the processing device, is at least at the height of the upper edge of the processing elements but no higher than the height of the upper surface of the rotor. As a result of this development, the inlet gap adjacent to the upper surface of the rotor has a wider portion, which makes it easier for material to be processed to enter the processing gap. 
     In addition, it is possible for the upper edge of the at least one rib to be formed having a termination surface that extends obliquely away from the wall lining element and in the direction from the second portion to the first portion. Said termination surface functions as an admission slope for the material to be processed, which slope facilitates the transfer of said material from the wider portion into the narrower portion. 
     The wall lining element may comprise four substantially vertical ribs for example, the two outer ribs of which extend only over the height of the first portion, while the two inner ribs extend into the second portion and preferably extend over the entire height of the wall lining element. Furthermore, an opening for an upper fastening screw may be provided in the second portion, between the two inner ribs, and an opening for a lower fastening screw may be provided in the first portion, between each of the two rib pairs formed by an outer rib and an inner rib, in order to fasten the wall lining element to the inner circumferential wall of the stationary housing. Furthermore, a widened depression may be provided adjacently to the openings, which depression receives the head of the relevant fastening screw. The fastening screws can thus be protected, by one rib pair in each case, from damage by material to be processed. 
     In order to be able to achieve continuous protection of the inner circumferential wall of the stationary housing by means of the wall lining elements, it is further proposed for the lateral edges of the wall lining elements to comprise projections that mutually overlap in pairs. For example, both lateral edges of at least one wall lining element may comprise a shoulder that extends substantially over the entire height of the wall lining element, the thickness of which shoulder is substantially equal to half the thickness of a base plate of the wall lining element, one shoulder being arranged adjacently to the surface of the wall lining element that rests on the inner circumferential wall of the stationary housing when the wall lining element is assembled, while the other shoulder is arranged so as to be remote from said surface. 
     In a development of the invention, it is proposed for at least one wear-protection element to be arranged on the upper surface of the base element of the rotor and/or on the lower surface of the connecting plate and/or on the upper surface of the connecting plate and/or on the outer circumferential surface of the connecting plate and/or on the inner circumferential surface of the connecting plate and/or on the radially outer surface of the bearing pins. 
     According to further aspects, the invention relates to a processing element and a wall lining element for the processing device according to the invention. Regarding the structure and the function of said processing element and wall lining element, reference is made to the above discussion of the processing device according to the invention. 
    
    
     
       The invention will be explained in greater detail in the following, with reference to the accompanying drawings and on the basis of two embodiments. In the drawings: 
         FIG. 1  is a perspective view of an embodiment of the processing device according to the invention; 
         FIG. 2  is a perspective cross-sectional view of a tower unit of the processing device from  FIG. 1 ; 
         FIG. 3  is a perspective view of a rotor of the processing device according to the invention, without processing and wear-protection elements attached thereto; 
         FIG. 4  is a perspective view of the rotor from  FIG. 3 , comprising attached processing and wear-protection elements; 
         FIG. 5  is a perspective cross-sectional view of the rotor from  FIG. 4 ; 
         FIG. 6  is a perspective cross-sectional view of a detail of the rotor from  FIG. 4 , the rotor being shown in a horizontal cross section; 
         FIG. 7  is a plan view of a portion of the detail of the rotor from  FIG. 6 ; 
         FIG. 8  is a perspective view of an embodiment of the wall lining element according to the invention; 
         FIG. 9  is a perspective rear view of the wall lining element from  FIG. 8 ; 
         FIG. 10  is a perspective view of an embodiment of a bearing-pin wear-protection element; 
         FIG. 11  shows an embodiment of a wear-protection element of the outer circumferential surface of the connecting plate; 
         FIG. 12  is a perspective cross-sectional view similar to  FIG. 2  of the tower unit of a second embodiment comprising an upper wear-protection plate. 
     
    
    
       FIG. 1  shows the processing device  10  according to the invention, which device comprises a tower unit  12  and a drive unit  14  that are arranged on a vibration isolator  16 . The vibration isolator  16  is in turn supported by a base  18  that can be connected to the foundations of a factory building or to further components of a processing facility for example. 
     The tower unit  12  comprises a stationary housing  20  which, in the embodiment shown in  FIG. 1 , is substantially cylindrical and comprises a feed opening  22  at the upper end thereof in order to be able to introduce material to be processed into the processing device  10 . The material processed by the processing device  10  according to the invention can subsequently leave the processing device  10  through the base  18  for example, which base thus also functions as a material discharge point  24  in the embodiment of the processing device  10  according to the invention shown in  FIG. 1 . 
       FIG. 2  is a cross-sectional view from the side of the tower unit  12  from  FIG. 1 , the cutting plane extending through a central axis formed by the cylindrical shape of the housing  20 . In this case, it can be seen in  FIG. 2  that the stationary housing  20  defines an inner cavity into which the feed opening  22  leads. A rotor  26  is received in the cavity of the stationary housing  20 , the underside of which rotor is connected, using reinforcement elements  28 , to an upper end of a drive shaft  30  that is rotatably mounted by means of a bearing  32 , an oil grease bearing in the embodiment shown in  FIG. 2 . A sheave  34  is provided at a lower end of the drive shaft  30 , which sheave is connected to the drive shaft  30  for conjoint rotation and is connected to a corresponding output shaft of the drive unit  14  by means of a belt, for example a V-belt. In the embodiment shown here, the unit that drives the output shaft of the drive unit  14  is formed as an electric motor. 
     The stationary housing  20  of the tower unit  12  is divided into a cover unit  36  and a pot unit  38 , the cover unit  36  being able to be raised off the pot unit  38  by means of a pivot device  40  and pivoted away from the pot unit  38  and/or pivoted towards the pot unit  38  and lowered onto said unit. 
       FIGS. 3 to 5  show the rotor  26  without the rest of the components of the processing device  10 . As can be seen in  FIG. 3 , the rotor  26  comprises a base element  44  on which bearing pins  46  are arranged, which bearing pins extend upwards, substantially vertically, from a substantially horizontal upper surface of the base element  44 . The bearing pins  46  are interconnected, at the upper surface thereof, by an annular connecting plate  48 . On account of the bearing pins  46  being connected both by the connecting plate  48  and by the base element  44 , forces acting on an individual bearing pin  46  are also distributed over the rest of the bearing pins  46 . 
     In this case, the bearing pins  46  are connected both to the base element  44  and to the connecting plate  48  by means of fastening screws  50  (only two of which have been provided with reference signs in  FIG. 3 ). In order to prevent the fastening screws  50  from being subjected to forces acting transversely to a screw longitudinal extension direction of the fastening screws  50  in addition to the retaining force applied by said screws between the connecting plate  48  and the bearing pin  46  and/or between the bearing pin  46  and the base element  44 , the bearing pins  46  are furthermore connected to the base element  44  and to the connecting plate  48  by means of fastening bolts  52 , the fits of the fastening bolts  52  in the corresponding recesses compared with the fits of the fastening screws  50  in the corresponding recesses thereof always being selected such that forces, apart from the above-mentioned retaining forces, acting on one bearing pin  46  are distributed to the connecting plate  48  and/or to the base element  44 , and thus to the rest of the bearing pins  46 , via the bolts  52  and not via the fastening screws  50 . 
     On the radially inner side thereof relative to the base element  44 , the bearing pins  46  comprise a V-shaped depression  54 . On the side thereof opposite the V-shaped depression  54 , the bearing pins  46  comprise receptacles  42  for bearing-pin wear-protection elements  56 , as shown in  FIGS. 3 to 5 . It can furthermore be seen from  FIG. 4  that the base element  44  is provided with a wear-protection plate  58  on the upper surface thereof and with first wear-protection elements  60  on the outer circumference thereof. The substantially discoid base element  44  is connected, on the upper surface thereof and in the region of the centre thereof, to an annular wear-protection plate  62 , as can be seen in  FIG. 5  for example, the central opening of which wear-protection plate in turn receives a wear-protection element comprising a conical mandrel  64 . In the embodiment shown, the conical mandrel of the corresponding wear-protection element  64  comprises a central through-opening, via which at least the wear-protection element comprising the conical mandrel  64  can be connected to the drive shaft  30  by means of a fastening screw  66 . As a result, the rotor  46  can be fastened to the drive shaft  30  at least in a direction that is axial thereto. 
     It can furthermore be seen in  FIGS. 4 and 5  that the connecting plate  48  comprises on the lower surface thereof a plurality of second wear-protection elements  68 , connected to said plate, and comprises on the outer circumference thereof a plurality of third wear-protection elements  70 , connected to said plate. The upper surface of the connecting plate  48  comprises an upper wear-protection plate  72 , a first embodiment of said upper wear-protection plate  72  being shown in  FIGS. 2 to 5 . Similarly to the connection between the connecting plate  48  and/or the base element  44  and the bearing pins  46 , at least the upper wear-protection plate  72 , and optionally also the remaining wear-protection elements, is/are connected to the connecting plate  48  by means of bolts  74  and by means of fastening screws  76 , the bolts  74  being designed to absorb the horizontal component of the forces acting on the upper wear-protection plate  72 . The embodiment of the upper wear-protection plate  72  shown in  FIGS. 2 to 5  comprises a central through-opening  78  having substantially the same diameter as the central opening of the annular connecting plate  48 . 
     Furthermore, processing elements  80  can be seen in  FIGS. 4 and 5  which, as shown in  FIGS. 6 and 7 , are substantially U-shaped. A central portion of the U-shape that connects the two free legs of the U-shape is spaced apart from the associated bearing pin  46 , optionally using adapter elements  82 , in a direction radial to the base element  44 . On the radially inner face thereof relative to the base element  44 , the adapter elements  82  comprise a V-shaped recess which corresponds to a V-shaped projection on a side of the central portion of the U-shape of the processing element  80  facing the free legs of the U-shape, such that, when assembled, the V-shaped projection of one processing element  80  engages in the V-shaped recess of an adapter element  82  associated therewith. The adapter elements  82  comprise V-shaped projections on the radially outer side thereof, which projections can engage in the V-shaped depressions  54  on the bearing pins  46 . 
     It can furthermore be seen in  FIG. 7  that the inner surfaces of the free legs of the U-shape of the processing elements  80  extend so as to be substantially mutually parallel, in the embodiment shown here said legs being slidably mounted on two lateral surfaces of an associated bearing-pin wear-protection element  56 . 
     The processing elements  80  are designed to be able to be produced by means of a casting process. 
       FIGS. 6 and 7  show that an inner circumferential wall of the stationary housing  20  of the tower unit  12 , in particular of the pot unit  38 , is provided with wall lining elements  84 . The wall lining elements  84  are shown in greater detail in  FIGS. 8 and 9 . In this case, the wall lining elements  84  are curved such that they can be attached in the circumferential direction along the inner circumferential surface of the stationary housing  20 , so as to adjoin one another. In the embodiment shown here, one wall lining element  84  in each case comprises four parallel ribs  86  on the radially inner surface thereof, the two outer ribs  86  extending only over a first region  88 , while the two inner ribs  86  extend both over the first region  88  and in part over a second region  90 . In this case, the end faces of the two outer ribs  86  facing the second region  90  are inclined so as to extend radially inwards, towards the first region  88 . In each case, a recess  92  for a fastening screw  94  is provided in the first region  88 , between the outer rib  86  and the central rib  86  adjacent thereto (as shown in  FIGS. 6 and 7 ). A further recess  92  for a fastening screw  94  is provided in the central region  90 , between the two central ribs  86 . The end faces of the wall lining elements  84  extending perpendicularly to the circumferential direction are provided with projections  95  such that, when the wall lining elements  84  are assembled, two adjacent wall lining elements  84  mutually overlap in each case (see  FIGS. 6 to 9 ). 
       FIG. 9  is a rear view of the wall lining element  84 , in which three recesses  92  for the fastening screws  94  can be seen. Each recess  92  is surrounded by a projection  96 . In this case, the projections  96  function as spacers from the inner circumferential surface of the stationary housing  20 . A defined contact region is thus formed between the inner circumferential surface of the stationary housing  20  and the projections  96  of the wall lining elements  84 . If the inner circumferential surface of the stationary housing  20  is provided with recesses corresponding to the projections  96 , the projections  96  of the wall lining elements  84  can also be used for positioning the wall lining elements  84  on the inner circumferential surface of the stationary housing  20 . 
     In the following, the mode of operation of the processing device  10  will be described. 
     Material to be processed that is introduced into the stationary housing  20  of the tower unit  12  via the feed opening  22  falls onto the base element  44  and/or onto the wear-protection elements and wear-protection plates fastened thereto. Due to the rotation of the rotor  26 , which rotor is driven by the drive unit  14 , a V-belt (not shown) and the drive shaft  30 , the material to be processed that strikes the rotor is accelerated radially outwards such that it impacts against either a wall lining element  84  or a processing element  80  and can be crushed there. Material rebounding from the wall lining elements  84  is captured by the outer surfaces of the free legs of the U-shape of the processing element  80  and crushed further. Material that is present in the region of the wall lining elements  84  can be captured by the tips of the free ends of the U-shape of the processing elements  80 , the spacing of which from the wall lining elements  84  defines a processing gap  98  (see  FIGS. 6 and 7 ) in which the material to be processed is furthermore subjected to shearing stress and can thus be crushed further. Sufficiently crushed material subsequently falls through an outlet gap  100  between the wall lining elements  84  and the wear-protection elements attached to the base element  44 , in particular the lower wear-protection plate  58 , into a region below the base element  44 , from where the processed material can be removed from the processing device  10  via the material discharge point  24 . 
     All the elements used for wear protection can be replaced if necessary. In particular, in the event of wear of the tips of the U-shape of the processing elements  80 , and an associated widening of the processing gap  98 , the processing gap  98  can be adjusted by radially displacing the processing elements  80 . In order to achieve a radial displacement of the processing elements  80 , the adapter elements  82  can be replaced by adapter elements  82 ′ of an almost identical construction, of which only the spacing between the V-shaped recess and the V-shaped projection differs from the adapter elements  82 . Selecting an adapter element having a suitable spacing between the V-shaped recess and the V-shaped projection makes it possible for the relevant processing element  80  to be radially positioned such that a desired processing gap  98  can be maintained. 
       FIGS. 10 and 11  show two wear-protection elements by way of example,  FIG. 10  showing a bearing-pin wear-protection element  56  and  FIG. 11  showing a third wear-protection element  70  that is used to protect the outer circumferential surface of the connecting plate  48 . The wear-protection elements  56  and  70  each comprise a support  56   a  and  70   a , respectively, which is produced from metal, for example, and to which a hard-weld coating  56   b  and  70   b , respectively, is applied, which coating functions as an impact layer for impacting material. 
       FIG. 12  shows a second embodiment of a processing device according to the invention, or of the tower unit of said device, comprising a rotor, said device substantially corresponding to the processing device  10  according to  FIGS. 1 to 11  and differing from the processing device  10  described above mainly in the embodiment of the upper wear-protection plate. Therefore, in  FIG. 12 , similar parts are provided with the same reference signs as in  FIGS. 1 to 11  but increased by 100. The processing device  110  according to  FIG. 12  will be described in the following only insofar as it differs from the embodiment according to  FIGS. 1 to 11 , reference hereby otherwise being explicitly made to the description of the embodiment according to  FIGS. 1 to 11 . 
     The tower unit  112  shown in  FIG. 12  comprises a stationary housing  120  in which a rotor  126  is received, said element being analogous to the embodiment described above. An annular connecting plate  148  that connects a plurality of bearing pins  146  is arranged on said plurality of bearing pins, on which plate an upper wear-protection plate  172  is in turn arranged. 
     In comparison with the annular upper wear-protection plate  72  of the processing device  10 , the upper wear-protection plate  172  of the processing device  110  is substantially discoid. This means that material to be processed that is introduced into the stationary housing  120  of the tower unit  112  through a feed opening  122  does not fall directly onto a base element  144  or onto wear-protection elements attached thereto, but instead first falls onto the upper wear-protection plate  172 . From there, the material to be processed is accelerated radially outwards due to a rotation of the rotor  126 , similarly to the material to be processed described above which strikes the base element  44  of the processing device  10  and is accelerated. On an outer circumferential wall of the stationary housing  120 , the material to be processed strikes wall lining elements  184  which are identical to the wall lining elements  84  described above. The wall lining elements  184  are in particular arranged relative to the upper wear-protection plate  172  in such a way that a first region  188  (see reference sign  88  in  FIG. 8 ) of the wall lining elements  184  is arranged below the upper surface of the upper wear-protection plate  172 , such that material to be processed impacts the wall lining elements  184  in a second region  190  (see reference sign  90  in  FIG. 8 ) of the wall lining elements  184 , and ideally undergoes a first material crushing process there. The material to be processed can then fall from the second region  190  of the wall lining elements  184  into the first region  188  of the wall lining elements  184 , and this is promoted by the above-described different embodiment of the second region  190  compared with the first region  188  of the wall lining elements  184 , in order to be correspondingly processed in said first region in the manner described above. 
     It can further be seen in  FIG. 12  that a dog device  173  is arranged on the upper wear-protection plate  172 , which dog device is cross-shaped in the embodiment shown here. The dog device  173  is connected to the upper wear-protection plate  172  by means of projections and/or fastening screws and associated recesses. In this case, the dog device  173  prevents the upper wear-protection plate  172  from moving through, below the material to be processed, without providing said material with a sufficient radial acceleration component. 
     Since material to be processed that is introduced into the stationary housing  120  cannot fall centrally on the base element  144 , there is no need to provide the radially innermost wear-protection element on the base element  144  with a conical mandrel, such as the wear-protection element comprising the conical mandrel  64  in the processing device  10 , in order to distribute the material to be processed, striking said element, radially outwards from the centre. 
     It should also be added that the connecting plate  148  which, in the embodiment shown in  FIG. 12  is identical to the connecting plate  48 , can also be discoid, for example, when using a discoid upper wear-protection plate  172 .