EP1625889B1 - Device and method for comminution and use thereof - Google Patents

Abstract

The device comprises a rotating drum housed in a casing controlled to change the direction it turns at regular intervals. It has hammers around the roller, and grate acting as an anvil whereby the grills of the grate are located in the spaces formed by the transverse planes next to the hammers. The minimum distance of the grills to the lengthwise axis of the drum is smaller than the lengthwise axis of the drum or is the same as it and the minimum distance of the grills to the lengthwise axis of the drum can be varied in the direction of the fill opening.

Description

The present invention relates to a device for crushing various materials based on a hammer mill. This device is particularly suitable for comminuting large quantities of paper, cardboard, cardboard, etc. The invention also relates to a method for comminuting materials and to the use of the method according to the invention and of the device for comminuting paper, cardboard, cardboard. Etc.

Many of the devices currently available on the market for shredding paper and other materials are based on a combination of tearing and cutting of the materials to be shredded, with cutting usually being the main focus. For example, describes the DE 100 58 082 A1 Such a device with two counter-rotating driven shafts on which each uniformly spaced discs find, which in pairs with each other include a distance in which protrude the discs of the other shaft. The discs also have cutting edges. The material to be crushed, which is applied to the top of the counter-rotating waves is moved by the rotational movement on the intersecting portions of the two shafts and there crushed by the cutting blade until it fits through the spaces formed by the spaced discs and can fall through them. The shredded material can then be caught underneath the waves and transported, loaded into a container, packed or (bale) pressed.

A similar device is in the WO 88/01201 described. This has on the outer sides of the adjacent counter-rotating shafts in each case a further wave, on which also comminution discs are arranged. The comminution discs of the two outer shafts engage in an analogous manner in the respective adjacent inner waves and thus form next to the central main rupture of the central two waves two lateral Nebenerißwerke. Below the four waves is a corresponding curved sieve arch. The shredded by the mean Hauptreißwerk materials are transported to the forming the lateral Nebenerißwerke waves and further reduced by these until they are so small that they can fall through the sieve openings and can be collected below. In the WO 93/14874 is such device by applying ring segments on the crushing elements and equipped with fangs to improve the crushing effect further optimized.

Also, devices that have only one crushing roller, are known for crushing materials, such as from EP 0 908 238 A1 , The comminution is carried out by the fact that stand up from the circumference of the crushing roller cutting teeth, which cooperate with a fixed counter-knife arranged above it. As a result of the rotational movement of the roller, the material to be comminuted is transported to the gap between the blade and the counter-blade, and then cut during the passage of the gap.

Disadvantages of such devices are that in the crushing of hard or very solid materials there is a risk that the knives get stuck. Depending on how much the knives have already become stuck, it may therefore not be possible, even by reversing the rotary motion, to release the knives, so that the shredding process must be stopped in order to clean the shredding device.

If large quantities of paper are to be shredded, which already experience a certain amount of compression due to their weight, there is a risk that they will continue to be compressed. This forms almost homogeneous, as fused-looking chunks of paper, which also cause a jamming of the crushing discs. Such compressed paper is sometimes so hard that it can not be crushed even after release of the knife in a new pass through the crushing device.

In addition, crushing paper usually produces very small pieces, depending on the sieve that may be used. In particular, in the crushing of waste paper, which is to be recycled, it is necessary to collect the shredded paper or further process that it can be stored first or can be transported in large quantities without difficulty. The pressing to bales, which can be well stored in both large quantities and transport well, but with the resulting very small pieces of paper is difficult, as they separate more and more of the bale compound and the bale over time more uneven and becomes more unstable.

Since, in particular, paper actually tears better than can be cut, it is known from the prior art to use hammer mills for comminuting paper. The principle of such a hammer mill is for example in the US 1,096,835 described. In this case, a roller is regularly provided on its circumference with several hammers, which engage in the interstices of a comb-like anvil. The respective "teeth" of the comb represent individual small anvils. The material to be crushed on the roller is transported by the rotational movement of the roller with the hammers in the direction of the anvils and there depending on the size of the spaces between anvil and hammer in torn more or less small pieces. There, too, it is possible to determine the size of the material to be shredded by a grid attached to the outlet opening, so that the material to be crushed so often circulation and crushing by hammers and anvils learn until it has such a size that it the grid meshes fit through.

However, such hammer mills have the disadvantages, in particular in the comminution of paper, that the materials to be comminuted can not be supplied in large quantities at once, but only in relatively small portions. This requires advance either a portioning by hand, which increases the labor costs, or a machine pre-portioning, what associated with additional technical effort. In addition, comminution with hammer mill based crushers produces a noise level of the order of 90-95 dB. This is undesirable, especially when feeding the material to be shredded.

Out US 4,134,554 B is a hammer mill is known in which frequent blocking is avoided as a result of uneven paper feed with the aid of an adjustable grate. A sensor detects when the roller locks and causes the power to the roller drive motor to stop and raise the grate. In this way, the paper is moved away from the roll and reduces the pressure that the paper causes on the roll. The roller can then run freely again at normal speed.

The present invention was therefore based on the object to provide a device or a method that no longer has the above-mentioned disadvantages of the prior art. In particular, the device or method should be suitable for use with various materials, i.a. Even paper to crush, without the comminution devices jamming, or that the material to be crushed during comminution receives such a consistency that further processing is difficult. In addition, it should be possible to be able to supply larger amounts of material to be comminuted not in portions but at one time to the comminution device, the noise generated during comminution should be reduced as much as possible, as well as the power required for comminution, if possible with reduction of dust or Dirt formation.

The present object is achieved, inter alia, by a device for comminuting, with the feature combination specified in claim 1 or by a method as defined in claim 13.

In this case, the material to be crushed by conventional supply devices such as a conveyor belt, a tilting device or a forklift to be supplied to the filling opening. The filling opening is preferably located in the upper region of the housing.

The material to be shredded is preferably paper, cardboard, cardboard or similar materials, as well as materials which may contain any of these materials. In addition, however, any other materials to be comminuted, for example, one-component materials such as metal foils, sheets, plastics, wood and similar or multi-component materials such as refrigerators.

Advantageously, by the method according to the invention, the materials to be comminuted are comminuted to a size which makes it possible to convert the comminuted material into a readily storable and / or transportable form.

The outlet opening is preferably located directly under the roller. If this makes sense, however, it can also be attached laterally, in which case of course it must be ensured by means of apparatus that the shredded material also reaches the lateral outlet opening.

Preferably, the present device is controlled at least in one area, if possible, however, completely via a controllable control, which particularly preferably also includes the adjustment of the rotational speed. In addition to the rotational speed of the roller, the electronic control device should at least also the performance of the roller and / or the variation regulate the minimum distance of the ribs of the grate to the longitudinal axis of the roller in the direction of the filling opening. In addition, of course, known from the prior art further components or operations of the device can be controlled with the control device.

In contrast to the rotational speed of rolls in prior art size reduction devices, which is approximately 1000 rpm, preferably in the method according to the invention the roll is rotated at a speed of 15-100 rpm, more preferably 20-80 rpm. Minute, most preferably operated 23 - 55 revolutions / minute. It makes sense to set different rotation speeds in advance. The roller is controlled by the control device so that it reverses its direction of rotation periodically, and in a preferred embodiment, additionally the cycle time, the speed and the drive power are adjusted depending on the material to be shredded. This not only prevents the hammers from getting stuck in the crushing operation, but at the same time reduces the power to be applied from the material chopping roll because the material to be shredded on the roll is loosened by the reverse movement, thereby facilitating the crushing operation. The resulting noise level can be reduced to 80 to 82 dB.

In a preferred embodiment, the time intervals between the direction changes of the roller movement during the crushing process can be varied via the control device. Thus, for example, not only the distance between the ribs of the grate to the roll axis can be changed depending on the roll resistance in the crushing process compared to the filling opening, but also the time intervals between the changes in direction of the roll movement. The resistance is caused by the amount of material to be crushed, its weight or its density. The greater the resistance that the roller undergoes during the comminution process, the smaller should be the time intervals between the changes in direction of the roller movements so that the resulting loosening of the material to be shred facilitates the further comminution process.

Each first hammer-containing cross-sectional plane of the roll may independently comprise one or more first hammers. Preferably, at least two first hammers are arranged in hammers-containing cross-sectional planes, which are also preferably arranged symmetrically on the roll circumference due to the regular change in the direction of rotation of the roller. The hammers located in a cross-sectional plane may be both identical and different with respect to the shape, it being preferred that at least two like hammers be present in a cross-sectional plane. It is particularly advantageous if the hammers are firmly attached to the roller.

With respect to the material of the hammers, there is no particular limitation provided that the material is capable of withstanding the forces acting in the crushing operation and that the material has sufficient hardness to crush the material to be crushed as well.

The shape of the first hammers is generally not limited, but it has been found that these are particularly effective when the front surfaces and back surfaces of the first hammers are significantly smaller than their side surfaces. Particularly advantageously, the side surfaces of the first hammers are flat and parallel to the cross-sectional plane of the roller.

In a particularly preferred embodiment, the side surfaces of the first hammers seen in the direction of the roll longitudinal axis on the two longitudinal sides waistings. This facilitates the fixation of the material to be comminuted in the rotating movement of the roller in the recess formed thereby, similar to a paddle wheel, and thus simultaneously facilitates the comminution process. However, other forms are possible, the one allow such fixation of the material to be shredded during transport to Zerreißstelle. Due to the rotational movement of the roller, which is reversing at regular intervals, the sidepieces should preferably be mounted in mirror-symmetrical fashion so that the same effect is also produced in the opposite direction.

Optionally, additional counter-holders, for example on the grate, can be attached, which also serve to fix the material during the comminution process or during transport to the comminuting point. This is all the less necessary, the heavier the material or the greater the amount filled.

The hammers located in different cross-sectional planes may be both identical and different in shape and material. Preferably, all first hammers containing cross-sectional planes each have the same hammers.

Preferably, the hammers are arranged in different cross-sectional planes on the circumference of the roll such that the side surfaces of the hammers come to coincide with one another at successive cross-sectional planes in the direction of the roll longitudinal axis. In a particularly preferred embodiment, the individual hammers are at successive hammers having cross-sectional planes but successively offset by an identical angle in the same direction about the roll longitudinal axis, wherein at least as many hammers having cross-sectional planes, that at least two cross-sectional planes, the side surfaces of the hammers in Direction of the roll longitudinal axis seen come back to cover. However, it is particularly preferred that each roller arrangement has, in a cross-sectional plane, at least one analogous roller arrangement coming to cover in the direction of the roller longitudinal axis in a further cross-sectional plane, so that each roller arrangement occurs in at least two cross-sectional planes.

Particularly advantageous properties comprises a device in which two hammers are arranged symmetrically on the circumference of the roll in a hammers having cross-sectional plane, and the hammers of adjacent hammers having cross-sectional planes are arranged offset by 45 ° about the roll longitudinal axis. Starting from a cross-sectional plane having hammers, the lateral surfaces then cover at the fourth cross-sectional level following hammers.

On the first hammers one or more additional hammers are arranged. The shape of these other hammers is not particularly limited. Preferably, the one or more hammers are attached to the top of the first hammers. It is particularly preferred that the edge between the surface of the upper side and the surfaces of the front or rear side (relative to the rotational direction of the roller) of the first hammers, in each case in the direction of the front or the back, have flat flats on which additional hammers are attached.

The fact that the minimum distance of the ribs of the grate to the longitudinal axis of the roller is smaller than the maximum length of a vertical through the hammers to the longitudinal axis of the roller and larger than the radius of the roller, on the one hand allows the interaction of hammer and anvil, which causes a rupture, and on the other hand, that the rust does not collide with it, regardless of its shape during the rotational movement of the roller. When applying the material to be shredded, the minimum distance between the ribs of the grate and the longitudinal axis of the roller is preferably equal to the maximum length of the vertical through the hammers to the longitudinal axis of the roller and larger than the radius of the roller. By lowering the grate in the direction of the longitudinal axis of the roller, the applied material can then reach the area of the hammers so that crushing is possible. Also in the course of the crushing process, it may be useful to raise the grate back to this level, for example, if in spite of periodic reversal movement of the direction of rotation of the roller, the resistance increases or not reduced.

In a preferred embodiment, the minimum distance of the ribs of the grate (7) to the longitudinal axis of the roller is infinitely or stepwise, preferably continuously variable. It is particularly advantageous to control the variation of the said length of the vertical in the course of the comminution process via the control unit, since this length also controls the supply of the material to be reduced and thus the resistance presented to the hammers. The change in length causes the grate to move up and down in the direction of the filling opening.

According to the invention, the hammers protrude from the grate by a certain length corresponding to the difference between the maximum length of the vertical through the hammers to the longitudinal axis of the roller and the minimum distance of the ribs of the grate to the longitudinal axis of the roller or are with this at the same height. Depending on the material to be comminuted, this should be 0-500 mm, preferably 80-200 mm, particularly preferably 100-150 mm.

The filled, to be shredded material is therefore on both the rust and partly on the hammers. Depending on the amount, the density and the weight of the filled material to be crushed, the rotational movement of the roller, which causes the comminution process, experiences a different resistance, which manifests itself in a different current consumption of the roller. With the aid of the control device can preferably initiate a certain existing resistance or the associated power consumption, that the length of said distance of the ribs of the grate to the longitudinal axis of the roller is changed, that is, that the grate moves up or down compared to the filling opening , With greater resistance, the grate should move upwards to reduce drag.

However, the minimum distance of the ribs of the grate to the longitudinal axis of the roll must still be smaller than the maximum length of a vertical line through the hammers to the longitudinal axis of the roll or equal to this length be to allow further comminution. In this way, the resistance to the hammers due to the rotational movement of the roller and thus also the power consumption, that is to say the power of the roller, can be adapted to changed conditions during the comminution process and thus minimized overall.

Preferably, the ribs of the grate, seen in the direction of the roll longitudinal axis, are W-shaped and rounded at least at the central point, wherein the apex of the central rounding of the rib is below the upper end of the side legs of the rib, the length of the perpendicular of said Vertex to the roll longitudinal axis controllably varies, but is less than the maximum length of a perpendicular by the hammers to the longitudinal axis of the roll or equal to this length and greater than the radius of the roll, and wherein the mean rounding a portion of a parallel to the circumference of the roll Circular path represents.

The wedge-shaped ribs, which form the grid and are viewed in the direction of the longitudinal axis, whose center points are rounded, may likewise have rounded portions at the two outer w-tips. This has proven to be particularly advantageous for receiving the material to be shredded and its transport to the tearing point.

The side legs of the, seen in the direction of the longitudinal axis of the roll, w-shaped rib of the grate preferably protrude into the filling of the device, so that they form a kind of funnel, and the material to be crushed automatically by gravity alone in the sphere of influence of rollers and hammering. Understandably, this is the easier, the greater the mass of the filled material to be crushed

Below the grate of the first anvil, one or more further devices, for example further hammer-like elevations, may be arranged, which interact with the hammers of the rotating roller, and can also act as an anvil. This enables further comminution after the first comminution process by rusting as the anvil and first hammering. Preferably, the interaction takes place with the other hammers which are arranged on the first hammers.

The size of the materials emerging from the discharge opening after the comminution process can be influenced, inter alia, by the interspaces which result between the individual ribs of the grate and the cross-sectional planes having the hammers. Depending on the intended further processing of the resulting comminuted material, this can be taken into account in the structural design of the device.

Preferably, a transport device, a packaging device and / or a compression device, in particular a baling device, adjoins the comminution device. Further known from the prior art devices for further processing are also conceivable. The transport device can convey the shredded materials, for example via a conveyor belt in a container. It is also possible to attach a container directly below the outlet opening. Especially with paper, it is preferred to connect a baling device, since the resulting bales allow good storage and also easy transport.

Unlike commonly found in the prior art, the present inventive device at the outlet port preferably does not include a sieve-like member that dictates the size of shredded particles to be skipped, although it is generally possible. This has the consequence that usually the shredded material has a size which, for example in the case of paper, enables a baling and at the same time reduces the extraction of the shredded materials from the bale, as would be the case with a small size over time. In the aforementioned possibility of using the crushing device for crushing, for example, refrigerators As a result, the remaining shredded parts of the various materials from which a refrigerator is made, such as various metals, various plastics or foam, are large enough to be relatively well separated from one another. However, if too small parts were used, as is common in the prior art, it would be difficult to separate the different materials again.

Another object of the present invention is a method for crushing, which comprises applying the material to be ground on a grate, the crushing of material by means of hammers mounted on a rotating roller and the same time acting as anvil, such control of the roller, that these at regular intervals reverses its direction of rotation, and optionally comprises a change in the minimum distance of the ribs of the grate to the longitudinal axis of the roller in dependence on predetermined operating parameters. Suitable material to be shredded corresponds to that already described above.

Predetermined operating parameters include, for example, the resistance presented to the rotating roller, the power consumption of the roller or the like produced by the filled material to be crushed on the grate or hammers. represents.

Due to the use of hammers which cooperate with a rust acting as an anvil, the crushing of the material is preferably carried out by means of tearing and not by cutting. In particular, when shredding paper, this has the advantage that the disadvantages described in the prior art, that is, the jamming of the crushing roller and the compression of the paper, which has a similar effect due to the prevailing forces, such as merges and very hard clumps, is avoided in the inventive method.

By using a control device, preferably various processes during the process can be controlled electronically, in particular the speed of rotation of the roller, the power of the roller, the height of the grate in relation to the filling opening, which preferably by varying the minimum distance of the ribs of the grate to the longitudinal axis of the Roll can be done, the supply of the material to be crushed, for example by controlling the speed of a conveyor belt, and / or the further processing of the crushed material.

In contrast to the rotational speed of rolls in prior art hammer mills, which is about 1000 rpm, preferably in the method according to the invention the roll is rotated at a speed of 15-100 revolutions / minute, more preferably 20-80 revolutions / Minute, most preferably operated 23 - 55 revolutions / minute. It makes sense to set different rotation speeds in advance. According to the invention, the roller is controlled by a control device so that it reverses its direction of rotation _periodisch. This not only prevents the hammers from getting stuck in the crushing operation, but at the same time reduces the power to be applied from the material chopping roll because the material to be shredded on the roll is loosened by the reverse movement, thereby facilitating the crushing operation. The resulting noise level can be reduced to 80 to 82 dB.

In a preferred embodiment, the time intervals between the direction changes of the roller movement during the crushing process can be varied via the control device. Thus, for example, not only the height of the grate can be changed depending on the roll resistance in the crushing process compared to the filling opening, but also the time intervals between the changes in direction of the roll movement. The resistance is caused by the amount of material to be crushed, its weight or its density. The bigger the resistance that the roller undergoes during the comminution process, the smaller the time intervals should be between the changes in direction of the roller movements, so that the resulting loosening of the material to be comminuted facilitates the further comminution process.

The material obtained after the comminution process is preferably further processed directly after the comminution process in such a way that it is readily storable or transportable. For example, the shredded material can be transported from the outlet opening via a conveyor belt into a container, packed or compressed, wherein it is particularly preferred to press the obtained crushed material into bales.

Preferably, in the method, a device according to the invention described above is used.

The device described above and the method described above are preferably used for the comminution of paper, cardboard and / or cardboard or one or more products containing these materials. The above-described device or the described method are characterized in particular by the fact that even larger amounts of materials to be comminuted can not be added in portions, but can be filled and comminuted all at once. The required engine power is significantly reduced in comparison to known from the prior art devices, as well as the noise generated during the crushing process and the released during comminution dirt or dust. In addition, a jamming of the crushing roller is avoided in the course of the crushing process. This makes it possible to automate the entire process from transport to the filling opening, the filling, the comminution to the further processing after crushing, for example, baling.

The present invention is explained in more detail below with reference to a preferred embodiment, but without being limited thereto.

FIG. 1 shows a schematic side view of a preferred embodiment of the device according to the invention in the direction of the longitudinal axis of the roller.

FIG. 2 shows a schematic view of the device according to the invention FIG. 1 in the direction A, that is, a view of a device according to the invention.

Corresponding FIG. 1 a preferred embodiment of the device according to the invention comprises a housing (1) having upwardly a filling opening (2) and down an outlet opening (3) and in which a rotating roller (4) is mounted substantially horizontally. The two directions of rotation of the roller (4) are shown in the drawing by pointing in opposite directions arrows.

On the roll circumference of the longitudinal axis of the roller (4) pioneering first hammers (5) are firmly attached. A cross-sectional plane having hammers (5) preferably comprises two symmetrically arranged first hammers (5). In the subsequent hammers (5) having cross-sectional planes, the hammers are fixed to the roll circumference, that they are offset by 45 ° about the roll longitudinal axis.

The flat side surfaces of the hammers (5), with respect to the direction of rotation of the roller, have mirror-symmetrical side sections on their two longitudinal sides. The thus formed curved front of the hammers (5), based on the rotational direction of the roller (4), causes a fixing of the material to be crushed caused by the rotation movement to the grate (7), in which the crushing in the form of tearing by interaction with the hammers (5, 6) takes place.

The edge formed by the top and front or back of the hammers (5) is in terms of area in the direction of the front or back flattened. On these surface flattenings (13) are more hammers (6). The maximum length of a vertical through the hammers (5, 6) to the longitudinal axis of the roller (4) is denoted by b and corresponds to the maximum radius of a circular path described by the hammers.

In the housing above the roller (4) acting as an anvil grate (7) is mounted, the ribs, seen in the direction of the roll longitudinal axis, are W-shaped.

The w-shaped grate (7) has both a central rounding with the vertex (a1) and rounding at the outer tips. The length of the perpendicular from the vertex a1 of the central rounding, seen in the direction of the roll longitudinal axis, w-shaped rib of the grate (7) to the roll longitudinal axis is denoted by a. The length of the vertical (a) is less than the maximum length (b) of a perpendicular by the hammers (5, 6) to the longitudinal axis of the roller (4), the maximum radius, of a circular path described by the hammers (5, 6) is equal to or equal to this length, and greater than the radius of the roller (4). This means that a part of the hammers, corresponding to the difference between the maximum length (b) of the vertical through the hammers (5, 6) to the longitudinal axis of the roller (4) and the length of the vertical (a), over the ribs of the grate (7) protrudes in the direction of the filling opening (2) or is at the same height with these.

The individual ribs of the grate (7) are further each equipped with two counter-holding devices (8), which serve because of their shape that in the outer roundings of the w-shaped ribs of the grate (7) located to be shredded material in the rotational movement of Fix roller (4) to the comminution point. The length of the vertical (a) is variable by moving the grate (7) up or down via one or more steplessly adjustable hydraulic cylinders (10). This changes the height of the grate (7) in the direction of the filling opening (2) and thus also the proportion of the hammers (5, 6), which projects beyond the grate (7) in the direction of the filling opening (2).

For crushing the material to be crushed on the filling opening (2) is filled and then comes partly on the grate (7) and partly on the protruding from the grate (7) part of the hammers (5, 6) to lie. Due to the rotational movement of the roller (4), the material to be shredded is transported in the direction of the outer limbs of the w-shaped ribs of the grate (7), viewed in the direction of the roller longitudinal axis, and by co-operation of the hammers (5, 6) with the grate (FIG. 7), in particular in the region of the right or left vertex, depending on the direction of rotation of the roller, the outer rounding of the, viewed in the direction of the roller longitudinal axis, w-shaped ribs.

The already crushed material resulting from the main tearing process falls down by gravity and can be further comminuted there by way of a tearing device. In the present case, the auxiliary ripping device is formed by the funnel-shaped components (11) on which further components (9) also acting as anvil are arranged, which cooperate again with the hammers (5, 6) in the course of the further rotary movement of the roller. The crushed material thus obtained then exits through the outlet opening (3) from the crushing device.

To the outlet opening (3) can (not shown in the figure) connect a device for further processing, such as a conveyor belt, for example, in a container or to a packaging device, or in particular a baler connect.

FIG. 2 represents a plan view of the filling opening (2), with the housing walls (1) and located in the middle of the roller (4). At regular intervals parallel to the cross-sectional plane of the roll (4) are on the roll circumference of the longitudinal axis of the roller (4) pioneering first hammers (5) mounted on the flattened surface edges (13) from the top and front or back the other hammers (6).

The figure also clarifies that in successive, hammers (5, 6) having cross-sectional planes, the hammers (5) are arranged offset, since the other hammers (6) are correspondingly at different locations of the roll circumference. In the spaces formed by the hammers (5) adjacent, hammers (5) having cross-sectional planes, the ribs of the grate (7) are arranged. The individual ribs each have two opposing counter-holding devices (8).

The ribs of the grate (7) are arranged in the spaces formed by the hammers (5) adjacent, hammers (5) having cross-sectional planes that form between the ribs and the hammers (5) surrounding the rib more intermediate spaces (12), which absorb the shredded material produced by the interaction of the anvil ribs and the hammers (5, 6). The size of these gaps (12) influences, inter alia, the size of the materials obtained after the first comminuting step.

Claims (18)

1. A device for comminution, said device comprising a housing (1) having a feed opening (2), an outlet opening (3), and a rotating roll (4) arranged essentially horizontally in the housing and controlled in such a way that it reverses its direction of rotation at regular time intervals, first hammers (5) facing away from the longitudinal axis of the roll (4) being mounted on the roll circumference at regular spacings and parallel to the cross-sectional plane of the roll (4), a grid (7) functioning as anvil, which is mounted above the roll (4) in the housing, the minimum distance of the ribs of grid (7) to the longitudinal axis of roll (4) being smaller than the maximum length of a line through the hammers (5, 6) and perpendicular to the longitudinal axis of roll (4) or equal to said length and greater than the radius of the roll (4), said minimum distance of the ribs of grid (7) to the longitudinal axis of roll (4) being adjustable toward feed opening (2), and the ribs being arranged so as to be situated in the spaces formed by the hammers (5) of cross-sectional planes having neighboring hammers (5), characterized in that the device comprises a control means for the roll (4) which controls the roll in such a way that the roll (4) reverses its direction of rotation at regular time intervals, said first hammers (5) having one or more additional hammers (6) arranged thereon.
2. The device according to claim 1, characterized in that in each cross-sectional plane including hammers two or more hammers (5) are arranged symmetrically on the roll circumference.
3. The device according to claim 1 or 2, characterized in that the lateral surfaces of the first hammers (5) are parallel to the cross-sectional plane.
4. The device according to any of claims 1 to 3, characterized in that the hammers (5) in different cross-sectional planes are arranged on the roll circumference in such a way that, when viewed in the direction of the longitudinal axis of the roll, the lateral surfaces of the hammers (5) in consecutive cross-sectional planes coincide or are successively staggered in the same direction about the longitudinal axis of the roll by an identical angle each time, the number of cross-sectional planes having hammers (5) being at least such that in at least two cross-sectional planes the lateral surfaces of the hammers (5) re-coincide when viewed in the direction of the longitudinal axis of the roll.
5. The device according to any of claims 1 to 4, characterized in that in one cross-sectional plane having hammers (5) two hammers (5) are arranged symmetrically on the roll circumference, and the hammers (5) of cross-sectional planes having neighboring hammers (5) are arranged staggered by 45° about the longitudinal axis of the roll.
6. The device according to any of claims 1 to 5, characterized in that the lateral surfaces of the first hammers (5), viewed in the direction of the longitudinal axis of the roll, have narrowings on both long sides.
7. The device according to claim 6, characterized in that the narrowings are mirror-symmetrical.
8. The device according to any of claims 1 to 7, characterized in that the minimum distance of the ribs of grid (7) to the longitudinal axis of the roll (4) can be varied continuously or in steps toward the feed opening (2).
9. The device according to any of claims 1 to 8, characterized in that the ribs of the grid (7), viewed in the direction of the longitudinal axis of the roll, are of W-shaped design, and that the ribs are rounded at least on the central tip, the vertex of the central rounding of the rib being situated below the upper end of the lateral flank of the rib, the length of the vertical line from said vertex to the longitudinal axis of the roll being controllably variable but smaller than the maximum length of a line through the hammers (5, 6) and perpendicular to the longitudinal axis of roll (4) or equal to said length and greater than the radius of the roll (4), the central rounding representing a sector of a circle that is parallel to the circumference of the roll (4).
10. The device according to any of claims 1 to 9, characterized in that one or more additional means (9) functioning as anvil are arranged below the grid (7) serving as first anvil.
11. The device according to any of claims 1 to 10, characterized in that the device has an electronic means for controlling the rotational speed of the roll (4), the performance of the roll (4) and/or the minimum distance of the ribs of grid (7) to the longitudinal axis of the roll (4).
12. The device according to any of claims 1 to 11, characterized in that the comminuting device has a conveying device, a packaging device and/or a compressing device, especially a bale press, arranged downstream thereof.
13. A method for comminution using a device according to any of claims 1 to 12, said method comprising placing the material to be comminuted on a grid, comminuting the material by means of hammers mounted on a rotating roll and the grid which simultaneously functions as anvil, and optionally changing the minimum distance of the ribs of grid (7) to the longitudinal axis of the roll (4) in dependence on previously established operating parameters, characterized in that the roll (4) is controlled in such a way that it reverses its direction of rotation at regular time intervals.
14. The method according to claim 13, characterized in that comminution proceeds by tearing.
15. The method according to claim 13 or 14, characterized in that the rotational speed of the roll (4), the performance of the roll (4), the minimum distance of the ribs of grid (7) to the longitudinal axis of the roll (4), the supply of material to be comminuted and/or further processing of the comminuted material are controlled electronically.
16. The method according to any of claims 13 to 15, characterized in that the time intervals between the changes in direction of the motion of the roll vary during the comminution process.
17. The method according to any of claims 13 to 16, characterized in that the comminuted material is subsequently conveyed into a container, packaged or compressed, especially compressed into bales.
18. Use of the device according to any of claims 1 to 12 and/or the method according to any of claims 13 to 17 for the comminution of paper, cardboard and/or carton or products containing such materials.

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