EP3437741B1 - Crushing device with adjustable feed chute - Google Patents

Description

Field of the invention

The invention relates to a comminution device having a feed opening for feeding material to be comminuted, a comminution shaft for comminution of the fed material, and a cutting chamber arranged between the feed opening and the comminution shaft, which cutting chamber is delimited by a cutting chamber wall.

State of the art

Commercial waste, industrial waste, household waste, etc., e.g., (hard) plastics, textiles, composite materials, rubber, or waste wood (such as pallets and chipboard), require shredding before their final disposal or, in particular, before being returned to the recycling cycle. Single- or multi-shaft shredders are known in the art for shredding such waste. These are fed via a hopper, for example, by wheel loaders, forklifts, or conveyor belts.

A conventional shredder comprises a rotor unit in a cutting chamber, which includes one or more shredding shafts equipped with ripper hooks or knives. The knives are attached, for example, by screwing to knife carriers, which can be welded into knife pockets or, for example, screwed onto them, which are milled into the shredding shaft. The shredding of the fed material takes place between the knives rotating with the shredding shaft and stationary, i.e., non-rotating, counter knives (stator knives, scraper combs). The rotor unit is driven by a motor (e.g., combustion engine/electric motor).

A conventional shredder may also include a pushing device to push the fed material towards the rotating rotor.

After shredding between the rotating blades and the counter blades, the material can be discharged through a screening device (if available), which determines the shredding factor based on the screen size, and then transported further using a conveyor belt, a screw conveyor, a chain conveyor, or an extraction system, etc. Any material that is still too large is returned to the cutting chamber by the rotation.

For efficient shredding performance, it is crucial to continuously feed the material into the cutting area. There are essentially two different approaches:

Flat cutting room wall

Some shredding devices feature at least one flat cutting chamber wall that defines the cutting chamber on one side, combined with a pressure or re-pressing system that pushes the material toward the rotor or counterblade. This can be a type of pusher or a screw conveyor, for example. Flat means that the cutting chamber wall near the shredding shaft forms a small angle (e.g., within +/- 20°) to the horizontal.

The advantage of this is that by reducing the contact force of the pusher, even difficult-to-shred materials can be shredded without the machine coming to a standstill due to overload. However, the disadvantage is that the machine's throughput drops significantly while the pusher is retracting. On the other hand, with easy-to-shred materials, the pusher requires a great deal of force and thus energy to achieve high throughput.

Steep cutting room wall

Other shredding devices operate with a steep, in extreme cases even vertical, cutting chamber wall, whereby the material slides towards the cutting area due to its own weight, resulting in a large self-feed. A pusher can also be installed. Steep means that the The cutting chamber wall near the shredding shaft has a large angle to the horizontal (e.g., greater than 45°). With an upwardly curved cutting chamber wall, an even larger angle to the horizontal can be provided at an upper end of the cutting chamber wall.

Self-feed can be defined as the throughput rate of a material averaged over a predetermined time without re-pressing.

A more consistent throughput/throughput rate is advantageous, as the material constantly slides toward the cutting area. A disadvantage is that shredding difficult-to-shred materials (e.g., solid and/or coarse) is not possible at all, or only possible with increased rotor power or energy expenditure, or with a permanently low feed rate.

The document WO 2011/092588 A1 discloses a device for pre-shredding waste, comprising conveyors and shredding devices arranged at a predetermined operating distance from the conveyors. Furthermore, an adjustable pressure element is arranged immediately after the introduction section.

The document US 5,248,100 A discloses a waste shredding device comprising a housing, a feed plate, and a cutting device rotatably mounted on the housing above two rotatable blades. The inclination of the feed plate and the cutting device can be freely selected.

The document EP 1 371 420 A1 discloses a shredding machine having a pressing device with a pusher for pressing the material to be shredded against the rotor.

Description of the invention

The object of the invention is to at least mitigate the disadvantages in the case of a steep cutting chamber wall with self-feeding of the material. Shredding device is suitable for waste as described above in connection with the prior art.

The problem is solved by a comminution device according to patent claim 1.

The shredding device according to the invention comprises a feed opening for feeding the material to be shredded, a shredding shaft for shredding the fed material, and a cutting chamber arranged between the feed opening and the shredding shaft, which is delimited by a cutting chamber wall. The cutting chamber wall is pivotable in order to thereby regulate the self-feed of the fed material towards the shredding shaft based on its own weight. The shredding device according to the invention is characterized by a control device for adjusting a pivot angle of the cutting chamber wall; wherein the control device is designed to adjust the pivoting angle during operation of the comminution device as a function of a load applied to the comminution shaft and/or a torque applied to the comminution shaft and/or a current supplied to an electric motor driving the comminution shaft and/or a hydraulic pressure supplied to a hydraulic motor driving the comminution shaft and/or an operating state of an internal combustion engine driving the comminution shaft, so that the self-retraction is reduced upon an increase in the load and/or the torque and/or the current and/or the hydraulic pressure.

The shredding device according to the invention thus has the advantage that the self-feeding of the fed material to the shredding shaft, based on its own weight, can be regulated by pivoting the cutting chamber wall. Furthermore, the pivoting angle can be automatically adjusted to the material to be shredded during operation of the shredding device.

The waste shredding device according to the invention can be further developed as follows.

The at least one cutting chamber wall can be pivotable during operation of the comminution device, in particular pivotable in an automatically controlled manner. Additionally or alternatively, the at least one cutting chamber wall can be pivotable outside of operation of the comminution device, in particular pivotable manually.

Another development consists in that the cutting chamber wall can be pivoted about a pivot axis that is parallel or substantially parallel to a rotational axis of the comminution shaft, in particular wherein the pivot axis can be provided at a lower end of the cutting chamber wall. Substantially parallel means that the angle between the direction (or the direction vector) of the rotational axis of the comminution shaft and the direction (or the direction vector) of the pivot axis is 10° or less, preferably 5° or less, most preferably 2° or less. The angle between the axes is thus defined as the angle between the direction vectors, even for skew axes. In this way, the cutting chamber wall can be arranged close to the comminution shaft and/or the comminution shaft can be fed evenly along the axis or along the comminution shaft.

According to the invention, the comminution device further comprises a pressing device for pressing the material to be comminuted onto the comminution shaft.

With the pressing device, the material to be shredded can be temporarily pressed against the shredding shaft with increased pressure in order to increase the throughput.

A further development of this according to the invention consists in that the pressing device can be pivoted together with the cutting chamber wall.

This has the advantage that the relative position of the pressure device with respect to the cutting chamber wall remains constant when the cutting chamber wall is pivoted.

According to another development of the invention, the pressing device is rotatable about a rotation axis, in particular the rotation axis can be parallel or substantially parallel to the pivot axis but offset from it. Essentially parallel means that the angle between the direction (or direction vector) of the rotation axis and the direction (or direction vector) of the pivot axis is 10° or less, preferably 5° or less, most preferably 2° or less.

According to the invention, the cutting chamber wall has a cylindrical section, and the rotational axis of the pressure device is arranged along the center axis of the cylinder. This allows the pressure device to maintain a constant distance from the cutting chamber wall during rotation of the pressure device relative to the cutting chamber wall.

The above-mentioned object is also achieved by a method for operating a comminution device according to patent claim 5.

The shredding device has a feed opening, a shredding shaft, and a cutting chamber arranged between the feed opening and the shredding shaft, which is delimited by a cutting chamber wall. The method comprises the steps of: feeding material to be shredded into the feed opening and shredding the fed material with the shredding shaft, wherein the method is characterized by pivoting the cutting chamber wall in order to regulate the self-feed of the fed material towards the shredding shaft based on its own weight, adjusting the pivot angle during operation of the shredding device depending on a load applied to the shredding shaft and/or a torque applied to the shredding shaft and/or a current supplied to an electric motor driving the shredding shaft, and/or a hydraulic pressure supplied to a hydraulic motor driving the shredding shaft, and/or an operating state of an internal combustion engine driving the shredding shaft; wherein the pivot angle is adjusted so that the self-retraction is reduced upon an increase in load and/or torque and/or current and/or hydraulic pressure.

According to a further development, the pivoting of at least one cutting chamber wall can take place during operation of the comminution device, in particular by automatically controlled pivoting; or the pivoting of at least one cutting chamber wall can take place outside the operation of the comminution device, in particular by manual pivoting.

The method according to the invention can be further developed by the step of pressing the material to be shredded against the shredding shaft.

Further features and exemplary embodiments, as well as advantages of the present invention, are explained in more detail below with reference to the drawings. It is understood that this embodiment cannot exhaust the entire scope of the present invention. It is further understood that some or all of the features described below can also be combined in other ways.

Brief description of the drawings

Fig. 1

shows a first embodiment of the comminution device according to the invention.

Fig. 2

shows a second embodiment of the comminution device according to the invention.

Embodiments

Figure 1 shows a first embodiment of the comminution device according to the invention.

The Figure 1 The first embodiment shown shows a comminution device 100 with a feed opening 10 for feeding material to be comminuted, a comminution shaft 20 for comminution of the fed material, and a cutting chamber 30 arranged between the feed opening 10 and the comminution shaft 20, which is separated by cutting chamber walls (only one Cutting chamber wall 40a and a cutting chamber wall 40b (the two end walls are not shown). According to the invention, the cutting chamber wall 40a is pivotable during operation of the comminution device 100. The cutting chamber wall 40a is formed here merely by way of example, at least partially as a flat wall. However, in this first embodiment, a differently shaped cutting chamber wall can also be used (such as the cylindrical shape according to the second embodiment described below).

In this embodiment, the cutting chamber wall 40a can be pivoted about the pivot axis 41. The pivot axis 41 is parallel to the rotational axis 25 of the shredding shaft 20. The shredding shaft 20 has rotor blades 21. In addition to the shredding shaft 20 (several shredding shafts 20 can also be provided), the cutting chamber 30 also contains fixed counter blades 80. The rotation of the shredding shaft 20 about the rotational axis 25 shreds the material between the rotor blades 21 and the counter blades 80. An optional screen 60 can be used to determine the size below which the shredded material can leave the cutting chamber 30. The screen 60 then represents the lower boundary of the cutting chamber 30.

In Figure 1 is a first position I, in which the cutting chamber wall 40a is arranged at a steep angle, and a second position II, in which the cutting chamber wall 40a is arranged at a shallow angle. In position I, the self-feed of the material is greater due to its own weight than in position II. In this way, the throughput of the shredding device can be regulated. Furthermore, an adaptation to the material to be shredded can take place. In particular, in the case of a temporarily increased power supply to a motor (not shown) of the shredding shaft 20 due to a temporary supply of coarser material, a shallower angle can be set in order to reduce the feed of material.

A control device 50 is provided for adjusting a pivoting angle of the cutting chamber wall 40a. The control device 50 adjusts the pivoting angle during operation of the comminution device 100 depending on a load applied to the comminution shaft 20 and/or a torque applied to the comminution shaft 20 and/or a current intensity which an electric motor driving the shredding shaft 20. The pivoting angle is adjusted so that the self-retraction is reduced with an increase in load and/or torque and/or current, so that the angle of the cutting chamber wall 40a relative to the horizontal becomes reduced/flatter.

Figure 2 shows a second embodiment of the comminution device according to the invention.

The Figure 2 The second embodiment of the comminution device 200 according to the invention shown further comprises, compared to the first embodiment of the comminution device 100 according to the invention, a pressing device 90 for pressing the material to be comminuted against the comminution shaft 20. The cutting chamber wall 40a is at least partially cylindrical. The pressing device 90 is rotatable about an axis of rotation 91. This axis of rotation 91 also represents the axis of symmetry of the cylindrical section of the cutting chamber wall 40a. The rear cutting chamber wall consists of two axially adjacent parts 40c and 40d (which are, for example, perpendicular to the axis of rotation 91), wherein the part 40d is connected to the cutting chamber wall 40a and is pivoted together with the cutting chamber wall 40a.

In Figure 2A is a sectional view of the shredding device, with the pressing device 90 shown in a raised position. In Figure 2B the pressing device 90 is in a lowered position and presses the material to be shredded towards the shredding shaft 20.

The Figures 2C and 2D show the corresponding positions of the pressing device 90, whereby, however, the unit consisting of the cutting chamber wall 40a and the pressing device 90 is pivoted about the pivot axis 41, so that the cutting chamber wall 40a is steeper and thus a greater self-retraction is effected.

The Figures 2E and 2F show perspective views of the Figures 2C or 2B. However, since these are also sectional views, the front Cutting chamber wall (which, like the rear cutting chamber wall 40c, 40d, consists of two parts) not shown.

In summary: The cutting chamber wall 40a is not rigid but pivotable, allowing the self-feed to be adjusted during operation. The control device 50 detects the optimal self-feed for the current material. On the one hand, this makes the shredding device 100 more flexible, as it can adapt to a wide variety of materials. On the other hand, this results in more consistent shredding for many materials, thus increasing throughput.

The illustrated embodiments are merely exemplary and the full scope of the present invention is defined by the claims.

Claims (7)

1. A comminution device (200) comprising:

   a feed opening (10) for feeding material to be comminuted into a cutting chamber (30);

   at least one comminution shaft (20) for comminuting the fed material,

   wherein the cutting chamber (30) is arranged between the feed opening (10) and the comminution shaft (20) and delimited by cutting chamber walls (40a, 40b);

   wherein at least one cutting chamber wall (40a) is pivotable, to thereby control the pull-in action of the fed material to the comminution shaft (20) based on the fed material's own weight;

   further comprising:

   a control device (50) for adjusting a pivoting angle of the at least one cutting chamber wall (40a),

   wherein the control device (50) is configured to control the pivoting angle during operation of the comminution device (200) depending on a load applied to the comminution shaft (20) and/or a torque applied to the comminution shaft (20), and/ or a current supplied to an electric motor driving the comminution shaft (20), and/or a hydraulic pressure supplied to a hydraulic motor driving the comminution shaft (20), and/or an operating condition of an internal combustion engine driving the comminution shaft (20), so that the pull-in action is reduced when the load and/or torque and/or current and/or hydraulic pressure is increased;

   further comprising

   a pressing device (90) for pressing the material to be comminuted against the comminution shaft (20), wherein the pressing device (90) is rotatable about a rotary axis (91), wherein the pressing device (90) is additionally pivotable together with the cutting chamber wall (40a) as a unit;

   characterized in that

   the cutting chamber wall (40) comprises a cylindrical section and the rotary axis (91) of the pressing device (90) is arranged in the central axis of the cylinder.
2. The comminution device (200) according to claim 1, wherein the at least one cutting chamber wall (40a) is pivotable, in particular, automatically pivotable, during operation of the comminution device (200); or wherein the at least one cutting chamber wall (40a) is pivotable, in particular, manually pivotable, outside the operation of the comminution device (200).
3. The comminution device (200) according to claim 1 or 2, wherein the cutting chamber wall (40a) is pivotable about a pivot axis (41) parallel or substantially parallel to a rotation axis (25) of the comminution shaft (20) and wherein, in particular, the pivot axis (41) is provided at a lower end of the cutting chamber wall (40a).
4. The comminution device (200) according to claim 3, wherein the rotary axis (91) is arranged parallel or substantially parallel to but offset from the pivot axis (41).
5. A method for operating a comminution device (200), wherein the comminution device (200) comprises a feed opening (10), a comminution shaft (20), and a cutting chamber (30) arranged between the feed opening (10) and the comminution shaft (20), being delimited by cutting chamber walls (40a, 40b), wherein the method comprises:

   feeding material to be comminuted into the feed opening (10);

   comminuting the fed material with the comminution shaft (20);

   pivoting at least one cutting chamber wall (40a) in order to control the pull-in action of the fed material to the comminution shaft (20) based on the fed material's own weight; and

   adjusting the pivoting angle during operation of the comminution device (200) depending on a load applied to the comminution shaft (20) and/or a torque applied to the comminution shaft (20), and/or a current supplied to an electric motor driving the comminution shaft (20), and/or a hydraulic pressure supplied to a hydraulic motor driving the comminution shaft (20), and/or an operating condition of an internal combustion engine driving the comminution shaft (20),

   wherein the pivoting angle is adjusted such that the pull-in action is reduced based on an increase in the load and/or the torque and/or the current and/or the hydraulic pressure;

   wherein a pressing device (90) for pressing the material to be comminuted against the comminution shaft (20) is rotated about a rotary axis (91), and is additionally pivoted together with the cutting chamber wall (40a) as a unit,

   characterized in that

   the cutting chamber wall (40) comprises a cylindrical section and the rotary axis (91) of the pressing device (90) is arranged in the central axis of the cylinder.
6. The method according to claim 5, wherein the pivoting step comprises:

   pivoting, in particular, automatically pivoting, the at least one cutting chamber wall (40a) during operation of the comminution device (200); or

   pivoting, in particular, manually pivoting, the at least one cutting chamber wall (40a) outside the operation of the comminution device (200).
7. The method according to claim 5 or 6, having the further step of:
   pressing the material to be comminuted against the comminution shaft (20).