DRUM SHREDDER AND SHREDDING SYSTEM

Description

Field of the Invention

[0001] The present invention relates to a drum shredder and a shredder system adapted for shredding low-density waste material, such as expanded polymeric material, while separating high-density waste material, such as metal, nails, concrete, or some kinds of cardboard.Background of the Invention

[0002] An important part of waste management is the separation of different materials, this is presently done at any recycling centre by the user, i.e. metal is separated from expanded polymeric material as materials are placed in different containers.

[0003] However, even when the materials are separated, there is still contamination. It is also not uncommon for expanded polymeric material to contain contaminations in the form of metal, such as nails or concrete or cardboard or other unwanted materials. The cardboard may be of the kind used for transport of domestic appliances together with the expanded polymeric material.

[0004] As a consequence, the expanded polymeric material is less pure, and the overall quality is lowered. Thus, there is a need for an apparatus capable of at least partly separating the expanded polymeric material from the contaminations. European patent application EP2042238A1 discloses a drum shredder with the features of the preamble of claim 1.Object of the Invention

[0005] It is an object of the invention to provide a drum shredder and a shredder system adapted for shredding low-density waste material, such as expanded polymeric material while separating high-density waste material, such as metal, nails, concrete, and some kinds of cardboard.Description of the Invention

[0006] An object of the invention is achieved by a drum shredder for shredding low-density waste material, such as expanded polymeric material while separating high-density waste material from said low-density waste material.

[0007] The expanded polymeric material may be expanded foam such as EPS (expanded polystyrene).

[0008] The EPS may be material sold under the trademark flamingo.

[0009] In the present application high-density waste material should be understood as metals, concrete, wood or some kinds of high density cardboard.

[0010] The drum shredder is designed for shredding expanded polymeric material and separating expanded polymeric material from high-density material, such as metals, concrete, and cardboard. However, it is expected that the drum shredder can separate contamination from other types of main waste material provided that the contamination has a higher density than the main waste material, i.e. being high-density waste material compared to material to be shredded.

[0011] The drum shredder comprises a rotatable drum comprising ripping means; a shell encompassing at least a part of the rotatable drum, thereby defining a channel around the rotatable drum, a channel inlet for receiving waste material and a channel outlet; and a trap positioned between the channel inlet and the channel outlet, the trap comprising a trap chamber for accumulating high-density material and optionally, a trap outlet for removing the accumulating high-density material.

[0012] The waste material will be dragged by ripping means of the rotatable drum through at least a part of the channel, while the waste material is divided into smaller parts. When the rotating drum rotates along a rotational direction, then an uplift will be created in the rotating drum in the rotational direction, causing low-density waste material to be lifted relative to high-density material. At least a part of the high-density material will then accumulate in the trap volume of the trap from where it can be removed through the trap outlet. Thus, the waste material moving through the channel outlet will have a higher purity compared to the waste material moving through the channel inlet.

[0013] In a preferred embodiment, the trap is positioned between the channel inlet and the channel outlet in the rotational direction of the rotatable drum. This will increase the separation efficiency significantly.

[0014] The rotatable drum may have a diameter of 500-2000 mm or 600-1600 mm or 800-1300 mm or 900-1100 mm or 1000 mm.

[0015] The longitudinal length of the drum may have a length between 400-2500 mm or 500-2200 mm or 600-2000 mm or 750-1200 mm or 1000-2000 mm or 1250-1600 mm or 1500 mm.

[0016] The shell may be positioned at a distance of 30-50 mm or 35-45 mm or 40 mm from the drum.

[0017] The rotatable drum may have a rotational speed of 25-50 rotations per minute or 30-40 rpm, or 35 rpm.

[0018] The ripping means may be saw teeth for gripping and dividing the material.

[0019] The saw teeth may be positioned in parallel lines along the longitudinal direction of the rotating drum.

[0020] The saw teeth may be radially and longitudinally offset such that the saw teeth will grip the material one at a time, which will even out the required rotational force to be provided by a motor.

[0021] The radially and longitudinally offset of saw teeth ensure that the saw teeth in effect cover the entire length of the rotatable drum.

[0022] The length of the saw teeth may be 10-30 mm or 15-25 mm, or 20 mm. Thus, there will be a distance between the saw teeth and the shell. The effect of this is that high density material, which is often made of harder material, will not to the same degree as the low-density material be divided by the saw teeth and thereby the uplift on the high density material will be even less compared to gravity.

[0023] The rotatable drum may be provided with 2 to 10 rows of saw teeth, or 4 to 8 rows of saw teeth or 5-6 rows of saw teeth.

[0024] The saw teeth are particularly good at dividing expanded polymeric material, while not dividing metals, such as nails or concrete, and this will in most cases cause the uplift on said contaminations to be smaller compared to the gravitational pull. This will increase separation between the expanded polymeric material and the contaminations, which have a higher density, i.e. are high-density materials.

[0025] The drum shredder may be fed by gravity assistance. This can be done by having channel inlet in a top part of the drum shredder such that gravity can pull the waste material through the channel inlet.

[0026] The drum shredder may be fed by a press plate pressing waste material through the channel inlet.

[0027] In an aspect, the drum shredder may comprise an air flow means adapted to provide an air flow from the channel inlet to the channel outlet and / or from the trap towards the channel outlet causing low-density waste material to move towards the channel outlet while the high-density waste material remains in the trap.

[0028] The air flow means causing the mentioned air flow will greatly increase the separation of contamination from the wanted waste material, because the air flow increases the uplift on the waste material significantly. Expanded polymeric material, which has a low density compared to metal, concrete or cardboard, will constantly be lifted by the uplift as the uplift is larger than the gravitational force, while the uplift on the metal or concrete or cardboard is lower than the gravitational force causing the contamination (metal, concrete or cardboard) to settle in the trap.

[0029] The air flow may be flowing from the channel inlet past the trap to the channel outlet.

[0030] In some embodiments, the air flow may be chaotic in order to create whirls lifting expanded polymeric material, which may have settled in the trap.

[0031] In initial tests the addition of the air flow means to the drum shredder increased the separation of unwanted contamination material from the expanded polymeric material such that 90 % of the unwanted contamination material was separated. Thereby, the resulting expanded polymeric material is significantly purer, i.e. of higher quality compared with expanded polymeric material shredded by present day solutions.

[0032] The air flow means may be connected directly to the channel through part of the shell.

[0033] The air flow means may be connected indirectly to the channel through the channel outlet.

[0034] The trap may comprise one or more slits and / or one or more holes for allowing an airflow, while having a size that makes the slits and / or holes impermeable to expanded polymeric material. Thereby, this enables the air flow from the trap to the channel outlet.

[0035] In an aspect, the channel outlet may be positioned at a higher gravitational level relative to the trap. This will further increase the separation by making use of gravity.

[0036] In an aspect, the air flow means may comprise a pump adapted to provide suction. The pump is a simple way of achieving the air flow.

[0037] In some embodiments, the channel outlet may be connected to a buffer for holding a large volume of shredded material. The pump can be connected to the buffer and create a lower pressure in the buffer relative to the trap thereby causing an airflow from the trap towards the buffer i.e. towards and through the channel outlet. The buffer may be equipped with a shield in front of the pump, wherein the shield is adapted to prevent material from entering the pump.

[0038] In an aspect, wherein the trap may be formed by walls extending downwardly from the shell. Thereby, the trap volume is achieved by simple means.

[0039] In an aspect, the trap may comprise an auger for forcing the high-density waste material through the trap outlet. Thereby, the drum shredder can shred continuously while removing the high-density waste material continuously.

[0040] In an embodiment the auger may be controlled by a motor.

[0041] In an embodiment the auger may be actuated by person rotating the auger.

[0042] An object of the invention is achieved by a shredder system for shredding low-density waste material, such as expanded polymeric material, while separating high-density waste material.

[0043] The shredder system comprises a drum shredder; and a buffer connected to the channel outlet.

[0044] The shredded material, which is of a larger purity compared to the material entering the channel inlet, can then be removed from the buffer, and may then be reused.

[0045] In an aspect, the air flow means may be connected to the buffer.

[0046] The air flow means may then create a lower pressure in the buffer relative to the trap, thereby causing an airflow from the trap towards the buffer, i.e. towards and through the channel outlet. The buffer may be equipped with a shield in front of the air flow means, wherein the shield is adapted to prevent material from entering the air flow means.

[0047] The air flow means may be a pump.

[0048] In an aspect, the buffer may comprise a buffer exit connected to a compactor for compacting the low-density waste material.

[0049] Thereby, the volume of the waste material is reduced compared to the volume in the buffer and consequently transportation costs are reduced.

[0050] In an aspect, the shredder system may further comprise a moveable press plate for forcing waste material into the channel inlet. Thereby, it is ensured that all waste material enters the channel, furthermore, the speed of operation is increased.

[0051] The shredder system may include a container such as a mobile container. The container may at least party have stored within the drum shredder and / or the buffer.

[0052] The container may further have a moveable press plate at least partly stored within.

[0053] Use of a drum shredder for shredding expanded polymeric material and separating expanded polymeric material from high-density waste material.Description of the Drawing

[0054] Fig. 1 illustrates a drum shredder; Fig. 2 illustrates another view of the drum shredder; Fig. 3 illustrates a trap for use in a drum shredder; and Fig. 4 illustrates shredder system comprising a drum shredder. ItemReference numberDrum shredder10Drum20Ripping means22Sawtooth24Motor28Shell30Channel40Channel inlet42Channel outlet44Trap50Trap chamber52Trap outlet54Auger56Shaft58Air flow means60Pump62Shield64Shredder system100Buffer110Buffer exit112Compactor120Press plate130 Detailed Description of the Invention

[0055] Fig. 1 illustrates a drum shredder 20. The drum shredder 10 is adapted for shredding low-density waste material such as expanded polymeric material while separating high-density waste material.

[0056] The drum shredder 10 comprises a rotatable drum 20 with ripping means 22 in form of saw teeth 24 positioned radially offset along the longitudinal axis of the rotatable drum 20. The rotation of the rotating drum 20 is actuated by the motor 28. The drum 20 rotates counterclockwise in the present figure view.

[0057] The drum shredder 10 further comprises a shell 30 encompassing at least a part of the rotating drum 10. The shell 30 and drum 10 defines a channel 40, a channel inlet 42 for receiving waste material and a channel outlet 44. The waste material is to enter the channel inlet 42 and exit the channel outlet 44.

[0058] The channel inlet 42 is substantially placed on a lower half of the drum shredder 10.

[0059] The channel outlet 44 is substantially placed on an upper half of the drum shredder 10.

[0060] The drum shredder 10 further comprises a trap 50 positioned between the channel inlet 42 and the channel outlet 44 along the rotational direction of the drum 20. The trap 50 comprises a trap chamber 52 for accumulating high-density material and a trap outlet 54 for removing the accumulating high-density material.

[0061] The rotating drum 20 will drag waste material from the channel inlet 42 towards the channel outlet 44 this will generate an uplift, the resulting lift will be largest on low-density waste material, such as expanded polymeric material, compared to high-density waste material, such as metals, nails, concrete or hard cardboard. The consequence is that the high-density waste material will accumulate in the trap 50 from where it can be removed.

[0062] The trap 50 is formed by walls extending downwardly from the shell 30.

[0063] In the present embodiment the channel outlet 44 is positioned at a higher level than the trap 50.

[0064] The trap 50 may comprise an auger 56 for forcing the high-density waste material through the trap outlet 54 as shown in figure 3.

[0065] Fig. 2 illustrates cross-sectional view of the drum shredder 10 shown in figure 1. In this view, a floor is present to be used for guiding material towards the drum shredder 10.

[0066] The drum 20 in the figure 2 is illustrated with only a few saw teeth 24, however it may have as many as shown in fig. 1.

[0067] Fig. 3 illustrates a trap 50 for use in a drum shredder 10. The trap 50 is shown from different angles in Fig. 3A-E.

[0068] The trap 50 comprises a trap chamber 52 for accumulating high-density material and a trap outlet 54 for removing the accumulating high-density material.

[0069] The shown embodiment of the trap 50 comprises an auger 56 for displacing material towards the trap outlet 54. The trap outlet 54 is shown from a bottom view in fig. 3D.

[0070] Fig. 3E show a waste channel connected to the trap outlet 54 for leading the high-density waste material into the drawer for easier removal of the high-density waste material.

[0071] The auger 56 can be actuated by the shaft 58 thereby a person may actuate the auger 56.

[0072] Fig. 4 illustrates shredder system 100 comprising a drum shredder 10.

[0073] The shredder system 100 comprises the drum shredder 10 as described and shown in figure 1 and 2.

[0074] The shredder system 100 further comprises a buffer 110 connected to the channel outlet 44 for holding the shredded waste material.

[0075] The air flow means 60 in the form of a pump 62 is connected to the buffer 110 as shown in figure 4B as the pump. The buffer 110 comprises a shield 64 for preventing the shredded material from entering the pump 60

[0076] The buffer 110 comprises a buffer exit 112 connected to a compactor 120 for compacting the low-density waste material. Thereby, the total volume can be reduced, which will reduce transportation costs

[0077] The shredder system 100 further comprises a moveable press plate 130 for forcing waste material into the channel inlet 42.

Claims

1. A drum shredder (10) for shredding low-density waste material such as expanded polymeric material, while separating high-density waste material from said low-density waste material, the drum shredder (10) comprising - a rotatable drum (20) comprising ripping means (22); - a shell (30) encompassing at least a part of the rotatable drum (20), thereby defining a channel (40) around the rotatable drum (20), a channel inlet (42) for receiving waste material and a channel outlet (44); and - a trap (50); characterized in that the trap (50) is positioned between the channel inlet (42) and the channel outlet (44), the trap (50) comprising a trap chamber (52) for accumulating high-density material and optionally, a trap outlet (54) for removing the accumulating high-density material.

2. A drum shredder (10) according to claim 1, wherein the drum shredder (10) comprises - air flow means (60) adapted to provide an air flow from the channel inlet (42) to the channel outlet (44) and / or from the trap (50) towards the channel outlet (44) causing low-density waste material to move towards the channel outlet (44) while the high-density waste material remains in the trap (50).

3. The drum shredder (10) according to claim 1 or 2, wherein the channel outlet (44) is positioned at a higher gravitational level relative to the trap (50).

4. The drum shredder (10) according to claim 2 or 3, wherein the air flow means (60) comprises a pump (62) adapted to provide suction.

5. The drum shredder (10) according to anyone of claims 1-4, wherein the trap (50) is formed by walls extending downwardly from the shell (30).

6. The drum shredder (10) according to anyone of claims 1-5, wherein the trap (50) comprises an auger (56) for directing the high-density waste material towards the trap outlet (54).

7. A shredder system (100) for shredding low-density waste material such as expanded polymeric material while separating high-density waste material, the shredder system (100) comprising - a drum shredder (10) according to anyone of claim 1-6; and - a buffer (110) connected to the channel outlet (44).

8. The shredder system (100) according to claim 7, wherein the air flow means (60) is connected to the buffer (110).

9. The shredder system (100) according to claim 7 or 8, wherein the buffer (110) comprises a buffer exit (112) connected to a compactor (120) for compacting the low-density waste material.

10. The shredder system (100) according to anyone of claims 7-9, wherein the shredder system (100) further comprises - a moveable press plate (130) for forcing waste material into the channel inlet (42).