Abstract
A cutting device for comminuting pasty substances, has a nozzle with a nozzle housing which has at least one inlet and one outlet. The inlet has an entry flow cross section through which the pasty substance enters the nozzle. The outlet has an exit flow cross-section through which the pasty substance exits the nozzle. A flow duct leads from the inlet to the outlet. A rotating cutting tool is disposed on the outlet for cutting the exiting pasty substance. The exit flow cross-section has the shape of a closed or interrupted annular gap which is formed by a central member within the nozzle and an internal wall of the flow duct. The central member in the conveying direction of the pasty substance increases in terms of the cross section.
Claims
1. Cutting device for comminuting pasty substances, comprising (a) a nozzle having a nozzle housing which has at least one inlet having an entry flow cross section through which a pasty substance enters the nozzle, and an outlet having an exit flow cross section through which the pasty substance exits the nozzle, and a flow duct that leads from the inlet to the outlet; and (b) a rotating cutting tool disposed on the outlet for cutting the exiting pasty substance, wherein the exit flow cross section has a shape of a closed or interrupted annular gap which is formed by a central member within the nozzle and an internal wall of the flow duct, the central member in a conveying direction of the pasty substance increases in terms of cross section.
2. The cutting device according to claim 1, wherein the central member is configured so as to be integral to the nozzle housing or as a separate insert that is fastened in the flow duct.
3. The cutting device according to claim 1, wherein the central member is inclined in the conveying direction and extends from the internal wall of the flow duct into the flow duct.
4. The cutting device according to claim 1 wherein a flow cross-sectional face does not decrease in the conveying direction.
5. The cutting device according to claim 1 wherein a face of the exit flow cross section is not smaller than a face of the entry flow cross section.
6. The cutting device according to claim 1 wherein the central member is configured so as to be conical and/or so as to be continually enlarged in the cross section.
7. The cutting device according to claim 1 wherein the central member is configured as a hollow member.
8. The cutting device according to claim 1 wherein the central member is mounted so as to be longitudinally displaceable on the nozzle housing.
9. The cutting device according to claim 1 wherein a drive shaft of the rotating cutting tool is mounted in the central member.
10. The cutting device according to claim 1 wherein the exit flow cross section is configured as a single interrupted gap, and the central member configures a single web on the exit flow cross section.
11. The cutting device according to claim 1 wherein the central member is configured as a cone having a web that is disposed or configured on a shell face.
12. The cutting device according to claim 1 wherein the entry flow cross section continually transitions into the exit flow cross section.
13. The cutting device according to claim 1 further comprising protrusions for generating predetermined breaking points in the pasty substance which protrude into an annular gap in the exit flow cross section and are disposed or configured on the outlet.
14. The cutting device according to claim 1 wherein the rotating cutting tool has at least one blade that is inclined from the inside to the outside, counter to a rotation direction.
15. The cutting device according to claim 1 wherein the rotating cutting tool is mounted so as to be axially spaced apart from the central member and from the nozzle housing in the conveying direction.
16. The cutting device according to claim 1 wherein the rotating cutting tool has a plurality of blades or cutting elements.
17. The cutting device according to claim 1 wherein an annular gap surrounds the central member by more than 180.
18. A system, comprising: a cutting device according to claim 1; and a further processing installation on which the rotating cutting device is disposed and in which the comminuted pasty substance is further processed.
19. The system according to claim 18, wherein a negative pressure or a positive pressure which bears on the exit flow cross section prevails in the further processing installation.
20. The system according to claim 18 wherein the further processing installation is configured as a dryer, a fluid bed evaporation dryer, a roasting installation, a deep-frying installation, a granulating installation, a fluidizing installation, cooling installation, a mixer, or a homogenizer.
21. A method for comminuting pasty substances, comprising: (a) passing a pasty substance through a nozzle, wherein a cross-sectional shape of the pasty substance when passing through the nozzle from an inlet to an outlet of the nozzle is modified from an entry flow cross section to an exit flow cross section that deviates from the entry flow cross section; (b) squeezing the pasty substance exiting from the outlet of the nozzle having the exit flow cross section; (c) cutting the pasty substance during the exit thereof and/or upon the exit thereof from the outlet using a rotating cutting tool, wherein the pasty substance is cut to an elongate pellet and each cut is performed transversely to the exiting direction of the pasty substance and along a longitudinal side of the pellet such that the cutting face forms the longitudinal side.
22. The method according to claim 21 wherein the pasty substance is forced through the exit flow cross section in the form of an open annular gap.
23. The method according to claim 21 wherein the pasty substance is transferred in a continually shape-changing manner from the inlet to the exit flow cross section.
24. The method according to claim 23, wherein no splitting of the pasty substance into a plurality of substance flows is performed in the nozzle up to the rotating cutting tool.
25. The method according to one of claim 21 wherein the pasty substance is transferred from a round entry flow cross section to an open annular exit flow cross section.
26. The method according to claim 21 further comprising generating depressions as predetermined breaking points in the subsequently cut pellet on an external side of the pasty substance as the pasty substance exits from the outlet of the nozzle.
27. The method according to claim 21 further comprising setting the cutting speed of the cutting tool to be higher than the exiting speed of the pasty substance.
Description
DESCRIPTION OF THE DRAWINGS
[0039] The invention will be explained in more detail hereunder by means of the figures in which:
[0040] FIG. 1 shows a perspective view of a cutting tool;
[0041] FIG. 2 shows a sectional illustration of FIG. 1;
[0042] FIG. 3 shows a plan view of an outlet;
[0043] FIG. 4 shows a variant of an outlet design;
[0044] FIG. 5 shows illustrations of shaped members generated;
[0045] FIG. 6 shows a schematic illustration of the generation of the shaped members in a plan view;
[0046] FIG. 7 shows a sectional illustration of a variant of a cutting installation having a housing and a separate central member;
[0047] FIG. 8 shows a perspective partial sectional illustration of the embodiment according to FIG. 7;
[0048] FIG. 9 shows a perspective view of a housing having an inserted central member;
[0049] FIG. 10 shows a rear view of FIG. 7; and
[0050] FIG. 11 shows the nozzle housing in an individual illustration.
DETAILED DESCRIPTION
[0051] FIG. 1 in a perspective, partially transparent view shows a cutting device 10 for comminuting pasty substances, having a nozzle 20 which has a nozzle housing 21. The nozzle housing 21 in the exemplary embodiment illustrated is configured as a tube having a bend. The nozzle 20 has an inlet 22 having an entry flow cross section 23 which for improved clarity is plotted so as to be slightly offset. The pasty material to be comminuted is conveyed from the inlet 22 through the flow duct 26 formed in the nozzle housing 21 in the direction toward an outlet 24 having an outlet flow cross-section 25. This can be performed by a pump or similar which is connected to the nozzle 20 and is disposed upstream of the cutting device 10. A rotating cutting tool 30 having four blades 31 is disposed on the outlet 24. The cutting tool 30 is driven by way of a driveshaft 52 which in the region of the bend is guided out of the nozzle housing 21. The driveshaft within the flow duct 26 is mounted in a central member 28 which conjointly with an internal wall 29 of the nozzle housing 21 forms the outlet flow cross section 25. The central member 28 extends counter to the conveying direction from the outlet 24 into the flow duct 26. The central member 28 in the exemplary embodiment illustrated is configured in the shape of a cone and on the shell face thereof has a web 281 which bears on the internal wall 29 of the nozzle housing 21. An extension which reaches up to the internal wall 29 and runs out thereon or therein, such that a continual or almost continual transition from the substantially circular entry flow cross section 23 to the outlet flow cross-section that is configured as an interrupted annular gap 27 takes place, adjoins the tip of the cone of the central member 28. The extension can be fabricated so as to be separate from the cone-shaped central member 28; the central member 28 preferably forms an insert or a molding therein which without any further installations performs a transfer of the material flow from the inlet 22 to the outlet 24 without any splitting into two separate substance flows.
[0052] The cross-sectional face within the flow duct 26 from the inlet 22 up to the outlet 24 remains the same or at least is not decreased, even when the shape of the flow cross section varies from the inlet 22 up to the outlet 24.
[0053] Protrusions 271 which radially protrude into the outlet flow cross section are disposed on the central member 28 in the region of the outlet 24, said protrusions 271 being configured as blades or as impression elements and configuring incisions or depressions on the surface of the shaped member to be generated such that predetermined breaking points are created therein by way of which a defined breaking point and thus also a uniform length of the segments from the shaped member can be achieved. The protrusions 271 can be disposed on an attachment, on an annular attachment, or on a sleeve on the central member 28. The attachment or the sleeve can be disposed so as to be replaceable on the central member 28 so as to be able to generate dissimilar spacings of the predetermined breaking points or dissimilar geometries and so as to enable a replacement in the case of wear.
[0054] Alternatively or additionally to the protrusions 271 on the central member 28 such protrusions can also protrude from the outside, thus from the internal wall 29 of the nozzle housing 21, into the outlet flow cross-section. These protrusions can also be produced separately and be fastened to the nozzle housing 21 by way of an attachment, an annular attachment, or an insert. Alternatively, such protrusions can also be configured so as to be integral.
[0055] The blades 31 on the cutting tool 30 are bent backward, counter to the direction of rotation which is indicated by the arrow, such that a fin-type or sabre-type blade contour results. The blades 31 have a bevel that points away from the nozzle housing 21 so as to apply a separation impulse or a separation force when the pasty mass is cut or separated. A facilitated separation and an improved singularization of the cut-off shaped part from the following material flow that is forced through the flow duct 26 is achieved on account thereof.
[0056] FIG. 2 shows the cutting device according to FIG. 1 in a sectional illustration. The inlet 22 and the outlet 24 are configured at opposite ends of the nozzle 20. The central member 28 which has a substantially cone-shaped contour is disposed within the flow duct 26 which is formed by the tubular nozzle housing 21. The driveshaft 52 which drives the cutting tool 30 having the cutting edges 31 is guided through the central member 28. The cutting edges 31 completely sweep the outlet flow cross section 25 which is configured in the shape of an interrupted annular gap. The driveshaft 25 is mounted so as to be sealed in relation to the material transported in the flow duct 26 such that a motorized drive that is disposed outside the nozzle housing 21 cannot come into contact with the pasty substance. The driveshaft 52 can be mounted so as to be axially displaceable within the central member 28, preferably being mounted having a spring force in the direction toward the basic position illustrated. In the case of a disturbing item or a solid component hitting a blade 31 of the cutting tool 30, the cutting tool 30 can thus be repositioned in the conveying direction so that the item can exit and the cutting procedure can subsequently be continued.
[0057] It can be derived from FIG. 2 that the blades 31 are disposed so as to be spaced apart from the outlet 24 from the nozzle 20 and thus do not bear on the housing 21 or on the central member, or slide along said housing 21 or the central member. The pasty material is separated exclusively by the blades such that a minimization of wear can be achieved.
[0058] The central member 28 in FIG. 2 is illustrated as a separate component which is pushed into the nozzle housing 21 and fixed to the latter. A web 281 which ensures that the outlet flow cross section in the region of the outlet 24 is configured as an interrupted annular gap, in the exemplary embodiment illustrated as a circular interrupted annular gap, is molded or disposed on the cone-shaped central member 28. Other annular gap shapes, for example polygonal shapes or oval shapes, can also be present. Alternatively to a design embodiment of the nozzle 20 having the central member 28 in two parts or multiple parts, said nozzle 20 having the central member 28 can also be configured so as to be integral, for example by a casting method or a forming method in which an initially tubular basic part is used as the nozzle housing 21 and the central member 28 is bent inward or is formed therein. In order for the consistency of the cross section to be maintained, the nozzle housing 21 across the conveying direction in the direction toward the outlet 24 is enlarged in terms of the circumference such that the pasty medium does not jam within the nozzle 20. Since the central member 28 extends inward from the internal wall 29 in the direction of the flow duct 26 and in the conveying direction is configured so as to be of an enlarged volume, preferably so as to be of continually enlarged volume, and protrudes into the flow duct, the substance flow is transferred and formed so as to bear on the internal wall 29 and on the external contour of the central member 28 until the shape of the outlet flow cross section 25 is achieved.
[0059] A variant of a potential outlet opening as an interrupted annular gap 27 is illustrated in FIG. 3. The outlet flow cross section 25 is formed by the external contour of the central member 28 and the internal wall 29 of the nozzle housing 21. The annular shape of the gap is interrupted by the web 281. The final contours of the annular gap 27 are configured by the shape of the web 281. The length of the shaped member to be generated is substantially defined by the length of the annular gap, or of the radian measure of the interrupted outlet opening, respectively.
[0060] As an alternative to the embodiment having a substantially constant radius of the annular gap 24, a variant in which the web 281 configures dissimilar circle radii R1, R2 is shown in FIG. 4. The center of the annular gap 27 is in each case assumed to be the reference radius. The initial radius R1 is smaller than the final radius R2 when the cutting element (not illustrated) rotates in the direction of the arrow. The radius in the exemplary embodiment illustrated varies consistently from the initial radius R1 to the final radius R2 such that a spiral-type shape of the generated shaped product after cutting results. A continual variation of the radius is expedient for generating ideally uniform shaped products or pellets. In principle however, other deviating designs of shape of the annular gap 27, or of the interrupted annular gap 27, respectively, can also be used.
[0061] FIG. 5 shows two views of the shaped product 40 or pellet obtained by the cutting procedure. In the embodiment illustrated the pasty material has been squeezed through an annular gap such as is shown in FIG. 3, and cut off transversely to the exiting direction by the rotating cutting tool 30. An interrupted, annularly bent parallelepiped in which the length is defined substantially by the length of the annular gap results. The shaped product has two end sides 41 which are formed by the web 281, the substance flow of the pasty material being squeezed out of the outlet 24 so as to be separated and bent on said end sides 41. The cross section of the end sides is a parallelepiped; a total of four longitudinal sides are present, an external side 49 bearing on the internal side 29 of the nozzle housing 21 at the exit. The internal side 48 bears on the external side of the central member 28 and lies opposite the external side 49. Two mutually opposite longitudinal sides 43 which are configured in the longitudinal extent of the shaped member 40 and are formed by the blades 31 of the cutting tool 30 by successive cuts are furthermore configured. A separation from the following material flow is thus achieved by way of the device according to the invention by a rotating cut performed transversely to the exit direction along a longitudinal side 43 of the shaped member 40 to be generated.
[0062] The shape of the shaped member 40 initially depends on the shape of the annular gap 27 or of the outlet flow cross section 25. In as far as an attachment or inserts within the outlet flow cross section 25 are present, predetermined breaking points 47 or impressions in the external longitudinal side 49 or the internal longitudinal 48 can be incorporated by way of elements such as blades located therein. The thickness of the spatial member 40 is in particular influenced by the flow rate of the pasty substance and by the number of revolutions of the cutting tool, conjointly with the number of blades 31 and the orientation and disposal of the latter on the circumference of the cutting tool. As opposed to other pelletizing devices, the cutting faces 43 of the shaped members 40 are not located on the end sides 41 but on the longitudinal sides 43 of the pellets.
[0063] FIG. 6 shows a schematic plan view of an exiting substance flow which exits from the nozzle housing 21. The annular gap is bent such that a substance face that is bent into the image plane results. The blade 31 moves to the right in the direction of the arrow, while the substance flow moves downward in the conveying direction according to the direction of the arrow. A diagonal separation of an exiting bent substance face results on account of an oblique setting of the blade 31. By virtue of the angular position of the blade 31 a proportion of force acting in the conveying direction results such that the cut-off shaped product 40 is severed from the following substance flow, as illustrated, and is moved away from the nozzle exit by way of a slight rotating impulse.
[0064] A schematic sectional illustration of the cutting device 10 in which the nozzle is configured from a tube as a nozzle housing 21 that widens in a continually conical manner is shown in FIG. 7. The inlet 22 has a diameter that is smaller in relation to the outlet 24. A cone-shaped central member 28 in which a slot (explained below) of the nozzle housing 21 is inserted and fixed to the nozzle housing 21 is inserted within the nozzle housing 21. The central member 28 has a downwardly directed web 281 which penetrates the nozzle housing 21 and reaches up to the end face of the central member 28 at the side of the outlet. The otherwise encircling annular gap that is formed by the cone-shaped central member 28 is interrupted by way of the web 281. Since the cone-shaped central member 28 penetrates the nozzle housing 21, the central member 28, emanating from the inlet side, protrudes from the internal wall 29 increasingly into the flow duct 26 and by virtue of the enlargement of the nozzle housing 21 in the direction of the outlet completely or almost completely compensates for the increasing cross-sectional face. The face of the respective flow cross section thus remains substantially consistent in the conveying direction, optionally increasing so as to relax the pressure in the pasty substance that is created when the latter is pumped through the nozzle 20.
[0065] The driveshaft 52 is mounted within the central member 28, said driveshaft 52 being optionally mounted so as to be axially displaceable, and so as to protrude from the nozzle housing 21 where said driveshaft 52 is then driven outside the nozzle housing 21.
[0066] Sabre-type blades 31 by way of which the material that is squeezed through the outlet 24 is cut transversely to the outflow direction and along the longitudinal extent of the respective shaped members 40 generated are disposed on the cutting tool 30. In the exemplary embodiment of FIG. 7 the nozzle housing 21 and the central member 28 are configured as separate components and fitted inside one another. The exit flow cross section is formed by the external contour of the central member 28 and by the internal contour of the internal face 29 of the nozzle housing at the outlet 24.
[0067] FIG. 8 shows a perspective sectional illustration of FIG. 7 in which it can be seen that the cone-shaped central member 28 from a passage face through the internal wall 29 close to the inlet 22 continually increases in the direction toward the outlet 24 such that the cross-sectional shape of the inlet cross section 23 continually varies until an interrupted annular gap is generated. The longitudinal axis of the cone is not co-linear with the longitudinal axis or the central axis of the nozzle housing 21 in the outlet region, such that non-rotationally symmetrical shapes of flow cross sections that vary across the length of the flow duct result. No separation or splitting into two mutually separate substance flows of the material transported therethrough takes place within the flow duct 26, the material transported rather being transferred and transformed until said material has been brought into bent flat shape. A separation of the two ends of the annular gap takes place by way of the web 281. In principle, it is also possible for the web 281 to be dispensed with such that a complete annular gap is created on the outlet 24. A helical division of the pasty medium in this instance is performed by way of the blades 31 or of the at least one blade 31. A separation in terms of length can be performed by way of the incorporated predetermined breaking points in the further processing of the shaped products generated.
[0068] FIG. 9 shows the cutting device in a partially assembled state in which only the nozzle housing 21 having the central member 28 and the web 281 that is molded on the shell face of the cone-shaped central member 28 can be seen. The central member 28 is introduced into the housing by way of a slot such as is indicated with the reference sign 218 in FIG. 11, for example. The web 281 protrudes through the nozzle housing 21. Dissimilar variants of the central member 28 can be coupled to a nozzle housing 21 as the basic member by way of the separate design embodiment of the central member 28 and the nozzle housing 21. Worn-out components can likewise be more readily replaced.
[0069] FIG. 10 shows the assembled state according to FIG. 9 in a rear view seen from the inlet side. It can be seen that the central member 28 by way of the cone-shaped basic shape penetrates the wall of the nozzle housing 21. Material flowing from the inlet side to the outlet side is moved around the central member 28 at the penetration point, said material bearing on the internal wall 29 of the nozzle housing 21 and placing itself around this central member 28 without any separation of the substance flow being performed. A bore 285 for receiving the driveshaft 52 which is illustrated in FIG. 14 is incorporated within the central member 28.
[0070] FIG. 11 shows the nozzle housing 21 in an individual illustration, having the slot 218 that in the conveying direction extends up to the outlet 24. The slot 218 is shaped such that the web 281 is received in a tight fit and the cone-shaped central member 28 bears tightly on the nozzle housing 21 such that a tight closure and an ideally continual transition from the internal wall 29 of the nozzle housing to the cone-shaped central member 28 is established.
