Bulk waste compaction apparatus

Abstract

The invention concerns a bulk waste compactor for compacting waste such as plastic and other containers, paper, cardboard, tubular items and timber. The apparatus features a material-receiving opening and an elongated trough and includes a first auger mounted to rotate in, and drive material axially lengthwise of, the elongated trough, and a second auger arranged beside the first auger and mounted to counter rotate in, and drive material axially lengthwise of, the elongated trough. The elongated trough includes an outlet opening through which the material is driven by the augers and the augers each include an auger flight, the auger flights having a plurality of auger teeth projecting radially outwardly therefrom.

Description

Bulk waste compaction apparatusField of the invention

[0001] The present invention concerns a bulk waste compaction apparatus.Background of the invention

[0002] Various types of bulk waste compaction equipment have been developed, including devices to compact waste material such as recyclable waste material.

[0003] Waste compaction provides significant benefits, allowing more waste to fit into the same receiving space. Compacting waste on or after collection allows more waste to fit inside the collection vehicle or other collection, transport or processing equipment, making downstream material handling operation more efficient (for example, meaning fewer downstream handling operations are required). Different ways to process bulk waste material have been developed in order to compress and reduce volumes of waste materials through hydraulic, mechanical or pneumatic force, which has the effect breaking or shredding material and / or of forcing air and fluids out of the solid material. Such solutions include pendulum compactors, ram compactors, rotary and hammermill shredders and auger compactors.

[0004] Reference to any prior art in the specification is not an acknowledgment or suggestion that this prior art forms part of the common general knowledge in any jurisdiction or that this prior art could reasonably be expected to be understood, regarded as relevant, and / or combined with other pieces of prior art by a skilled person in the art.Summary of the invention

[0005] In accordance with the present invention, there is provided a bulk waste compaction apparatus with a material-receiving opening and an elongated trough, including: a first auger mounted to rotate in, and drive material axially lengthwise, of the elongated trough, and a second auger arranged beside the first auger and mounted to counter rotate in, and drive material axially lengthwise of, the elongated trough,wherein the elongated trough including an outlet opening through which the material is driven by the augers, and wherein the augers each include an auger flight, the auger flights having a plurality of auger teeth projecting radially outwardly therefrom.

[0006] In this way, waste material that is introduced to the apparatus is impacted by the interaction of the auger teeth of the respective augers resulting in cutting, tearing, breaking and / or deforming of the material as it is driven in the lengthwise direction of the augers to exit the trough though said outlet opening. This action reduces the size or length of the items of the material and thus increases or facilitates compaction of the resulting waste stream.

[0007] As will be appreciated, this driving action in the longitudinal direction (ie. in a direction substantially parallel to the axes of the augers, towards said outlet opening at the downstream end of trough) distinguishes the present invention significantly from conventional shredding and crushing apparatus, which receive material via an upper hopper inlet and then disgorge the shredded or crushed material downwardly, ie. the processed material dropping vertically out of the unit or into a receiving container.

[0008] In normal operation, the second auger rotates in the oppositive direction to the first auger in such a way that the interaction between the auger teeth on the respective augers acts in a downwards direction. In this way, material introduced into the apparatus from the material-receiving opening is caught and impelled between the first and second augers.

[0009] Preferably, the bulk waste compaction apparatus further includes a controller configured to control the rotation of the augers independently of each other. The controller is preferably configured to stop rotation of one of the augers independently of the other. Preferably, the controller is configured to monitor rotation of the first and second auger. The monitoring may include monitoring a current draw of electric motors operable to rotate the first and second augers. The controller may be configured to stop rotation of one auger when the current draw exceeds a threshold. It will be understood that other methods of monitoring the rotation of the augers may be employed, for example monitoring of the rotational speed of the augers or motors.

[0010] The controller is preferably further configured to reverse rotation of one of the augers independently of the other. Once this occurs, the direction of rotation of the augers is then the same. Preferably, the controller is configured to reverse the direction of the stopped auger independently of the other auger. The rotation may be reversed for a preset time duration or for a preset distance of rotary travel. The controller may be configured to stop the auger rotating in the reverse direction independently of the other auger. The controller may be configured to once more reverse rotation of the reversed auger so that the auger rotates in its normal operational direction.

[0011] An apparatus including a controller so configured allows the detection of blockages or impedance of the rotation of the augers and automatic remedial action to be taken. The stopping and reversing of one auger independently of the other can alleviate or remove the blockage, thereby allowing continued operation without intervention or monitoring by operational staff.

[0012] Preferably, the augers are independently driven by separate motors. The motors are preferably electric motors. Power may be transmitted from a motor to the respective auger via a drive chain, gear box or other suitable means.

[0013] Preferably, the auger teeth are disposed along the full length of the auger flights. Preferably, the auger teeth are defined by a peripheral edge of each of the auger flights. In this way, the auger flights and the auger teeth are unitary, ie. integrally formed. The auger teeth may be formed by cutting the tooth profile into the auger flight. It will be understood that the auger teeth may be formed by other means, such as stamping, casting or machining. Alternatively, or in addition, the auger teeth may be separate components affixed to the auger flights.

[0014] It will be understood that the auger teeth may take any form, provided that they function when interacting to cut, shred and / or deform items within the waste material. Ideally, the auger teeth are cutter teeth, each tooth having a generally sawtooth shaping, an acute edge and / or a leading point. This assists with the teeth snagging, tearing, cutting and / or puncturing waste items.

[0015] The pitch of the auger flights is preferably constant. The pitch of the auger flights may alternatively be variable along the length of the augers. The pitch of the augers may be in a range of 300mm to 900mm, for example around 600mm.

[0016] The diameter of the auger flights preferably tapers from the mounted end toward the opening. The diameter of the auger flight may alternatively be constant. The diameter of the auger flights may be in the range of 450mm to 1200mm, for example around 700mm.

[0017] Preferably, the elongated trough is shaped to direct introduced waste material to, and contain said material in, a part of the trough adjacent to the auger flights.

[0018] Static teeth may be provided on a bottom or lower surface of the trough. The static teeth may be arranged in regular rows of teeth. A single row of static teeth may be formed as a single component which is affixed to the bottom of the trough. Multiple rows formed in this manner may be affixed to the bottom of the trough to form regular rows of teeth. The rows are preferably angled with respect to the length of the augers so that the teeth are generally directed against the prevailing direction of material being driven by the augers. The static teeth may assist in cutting, shredding, and / or deforming material that passes over the static teeth due to the driving action by the augers on the material.

[0019] It will be appreciated that the static teeth may take any form, provided that they function to assist in cutting, shredding, and / or deforming items within the waste material. Ideally, the static teeth are cutter teeth, each tooth having a generally sawtooth shaping, an acute edge and / or a leading point. This assists with the teeth snagging, tearing, cutting and / or puncturing waste items which are driven across the static teeth by the augers.

[0020] The apparatus preferably includes a bulk waste container to receive material that has been compacted by the first and second augers and has passed through the outlet opening of the elongated trough. The bulk waste container may be separable from the rest of the apparatus, in order to convey the compacted waste to a receiving or subsequent processing station.

[0021] As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additives, components, integers or steps.

[0022] Further aspects of the present invention and further embodiments of the aspects described in the preceding paragraphs will become apparent from the following description, given by way of example and with reference to the accompanying drawings.Brief description of the drawings

[0023] Figure 1 shows a stationary compactor having an auger compactor in accordance with the present invention;

[0024] Figure 2 shows an alternative form of a stationary compactor having an auger compactor;

[0025] Figure 3 is a perspective view of an auger compactor in accordance with the present invention;

[0026] Figure 4 is an end view transverse to the augers of the compactor of Figure 3;

[0027] Figure 5 is a side view within the compactor, showing one auger;

[0028] Figure 6 is a perspective view of an auger of the compactor shown in isolation;

[0029] Figure 7 illustrates a further embodiment of an auger compactor in accordance with the present invention;

[0030] Figure 8 is a perspective partial view of the compactor of Figure 7;

[0031] Figure 9 is an end view transverse to the augers of the compactor of Figure 7; and

[0032] Figure 10 is a schematic flow chart of the control of an auger compactor in accordance with the present invention.Detailed description of the embodiments

[0033] The stationary compactor 10 of Figure 1 is designed for compacting large volumes of dry waste such as dry general waste, plastic and other containers, paper, cardboard, tubular items and timber. The aim of such processing is significant volume reduction, saving in collection and transport costs for waste and recycling services. Whilst the embodiments of the invention described and illustrated herein are staticcompactors, it will be understood that the invention could also be provided in a vehicle, such as a garbage collection and compaction truck.

[0034] The stationary compactor 10 is mounted on support rails 12 and includes a compacted waste receiving container 14 of elongated hollow form, the content to be discharged by way of forward discharge door 15. Rearward of compactor apparatus 10 is arranged auger compactor head 50, including an auger assembly (described further below) and a receiving hopper 16 with a generally upward-facing opening.

[0035] As illustrated in Figure 1 , the apparatus includes a bin lifter mechanism 18 arranged to lift and invert bins 20 to discharge waste material from the bins into hopper 16.

[0036] An alternative form of the apparatus is shown in Figure 2, in which the same reference numerals are used to identify the equivalent components. In both embodiments, container 14 is configured to be removable. The container can be detached from the compactor head 50 when full and transferred by truck as required for subsequent processing steps. The embodiment of Figure 2 does not feature an integrated bin lifter, the waste material being introduced to hopper 16 by other means.

[0037] Turning to Figure 3, auger compactor head 50 defines an elongated auger chamber for containing and processing received waste, defined by a chamber front wall 52, a chamber rear enclosure 54 (housing a drive assembly and defining a chamber rear wall), two chamber wall portions 56 and a chamber base portion 58 having curved sides which connect to the wall portions 56. The various components are all supported on a compactor head frame 51 .

[0038] Supported to the chamber rear enclosure 54 and mounted to rotate within the auger chamber is a first auger 60, comprising an auger shaft 62 - arranged in a generally horizontal direction and extending in the longitudinal direction of the stationary compactor 10 - carrying auger screw flighting 64. Also supported to the chamber rear enclosure 54 and mounted to rotate within the auger chamber is a second auger 61 comprising an auger shaft 63 - arranged in a generally horizontal direction and extending in the longitudinal direction of the stationary compactor 10 - carrying auger screw flighting 65.

[0039] The second auger 61 is arranged beside the first auger 61 (shafts 62 and 63 being parallel) and arranged to counter rotate to the direction of rotation of first auger 60. The first auger 60 rotates in a clockwise direction (when viewed from the chamber front wall 52) and the second auger 61 rotates in a counterclockwise direction. As will be understood, the flights of the augers are configured accordingly to ensure material is driven forward by the rotation of the augers in their respective normal operational directions.

[0040] The augers 60, 61 are disposed in the auger chamber such that the outer edge of flights 64, 65 are adjacent the surface of chamber base portion 58 (and also adjacent chamber wall portions 56). The outer edge of the flights 64, 65 of both augers are equipped with a plurality of spaced auger teeth 66, discussed in further detail below. Rotation of the augers 60, 61 results in waste in the hopper being engaged and impelled by the augers 60, 61 (in particular by the action of auger teeth 66) toward the space between the augers 60, 61 and driven in a forward direction towards auger chamber front wall 52.

[0041] Chamber front wall 52 is provided with an outlet opening 68, providing a connection between the auger chamber and the interior of compacted waste receiving container 14. Connected to chamber front wall 52 and around outlet opening 68 is a flange 70 extending in the longitudinal (i.e. axial) direction into the interior of compacted waste receiving container 14.

[0042] As best shown in Figures 4 and 5 (the walls shown in transparency in Figure 4 for visibility of the inner components), the diameter of the auger flights is greatest toward the chamber rear enclosure 54, where the augers 60, 61 are mounted, the diameter then reduces toward opening 68. In the depicted embodiment, the diameter of the auger flights tapers from about 700mm to about 570mm. This taper aids in driving material toward the opening 68. It will be appreciated that the auger flights may instead have a constant diameter. The diameter of the auger flights may be modified for different applications and sizes of machine. For instance, machines having an auger flight of greater than 700mm in diameter are contemplated.

[0043] The pitches of the auger flights in the depicted embodiment are approximately 600mm, the augers having a length of approximately 1900mm. In testing by the applicant, this pitch was found to be particularly beneficial for crushing and shredding ofcarboard cores or tubes, such items often being very difficult to process due to their strength and length. It will be understood that the pitch may be varied depending on the application and / or size of the machine.

[0044] Referring to Figure 6, which shows the left-hand side auger 60, the auger teeth 66 are cutter teeth, with a generally sawtooth shaping including a leading point, designed to facilitate the snagging, tearing, shredding, crushing, breaking and / or puncturing of waste items they meet. To this end, in the particular apparatus developed and tested by the applicant, the teeth comprise a forward-pointing ‘sharkfin’ shaping. Other suitable shapings are of course possible, depending on the particular application.

[0045] The auger teeth 66 are disposed along the auger flights 64, 65 to extend substantially along the full length of the auger shafts 62, 63. The outer peripheral edge of the auger flights 64, 65 defines the auger teeth 66. In this way, the auger flights 64, 65 and the auger teeth 66 are unitary, with the flight of the auger forming the auger teeth 66. The auger teeth 66 are preferably formed by cutting the tooth profile into the auger flights 64, 65. It will be understood that the auger flights 64, 65 and therefore auger teeth 66 may be formed by other means, such as stamping, casting or machining. To manufacture an auger, one or more segments of the auger flight 64, 65 are prepared with the desired auger teeth and then welded onto the shaft 62, 63. Alternatively, the teeth 66 can be cut into the auger flights 64, 65 after the one or more segments are attached to the auger shafts 62, 63.

[0046] Alternatively, or in addition, the auger teeth may be separate components affixed to the auger flights 64, 65 or auger shafts 62, 63. In this instance, the teeth 66 are then affixed to auger flight 64, 65 or auger shafts 62, 63 by a suitable method, such as welding or bolting.

[0047] As discussed above, waste that has been deposited in hopper 16 to fall into the chamber of the auger compactor will be drawn toward the area between the toothed augers where they shred or crush the material and drive it in a forward direction towards auger chamber front wall 52 and outlet opening 68.

[0048] As best seen in Figures 4 and 5, each auger 60, 61 is driven by a respective electric motor 74, 75 via a drive chain, which may be housed within chamber rearenclosure 54, with the motors mounted to the frame of the compactor head external of the auger chamber (see Figure 5).

[0049] A variation of the above embodiment is depicted in Figures 7 to 9. In this embodiment, static teeth 76 are provided on the chamber base portion 58. The static teeth are arranged in regular rows of teeth formed as a single component. Multiple rows of static teeth 76 are affixed to the chamber base portion 58, the rows angled with respect to the longitudinal direction of the augers 60, 61 . The static teeth 76 are therefore directed against the prevailing direction of material being driven by the augers 60, 61 . As will be understood, the path of material from the rear of the chamber 54 toward opening 68 is rarely in a straight line along the length of the augers 60, 61 , due to the rotation of the augers and the angle of the flights. Material may be displaced around the chamber by the action of the augers 60, 61 or may take a corkscrew path toward opening 68. As the material is driven through the chamber its prevailing direction of movement with respect to the chamber base portion 58 may therefore be at an angle to the auger shafts 62, 63. The angle of the static teeth 76 is selected in accordance with this prevailing direction of movement.

[0050] It will be appreciated that the static teeth 76 may take any form, provided that they function when interacting to cut, shred, and / or deform items within the waste material. Ideally, the static teeth 76 are cutter teeth, each tooth having a generally sawtooth shaping, an acute edge and / or a leading point. This assists with the teeth snagging, tearing, cutting and / or puncturing waste items which are driven across the static teeth by the augers. The static teeth 76 may assist in cutting, shredding, and / or deforming material that passes over the static teeth 76 due to the driving of the material by the augers 60, 61 . The shape, size, pitch and positioning of the respective sets of teeth 66 and 76 can be varied to suit the particular application.

[0051] The augers (including the auger flights and shafts) and the static teeth are preferably made from a suitable grade of steel. For example, a mild steel such as grade 350 steel. As would be apparent to the skilled person, other grades and types of steel, for example stainless steels may also be suitable depending on the application.

[0052] During operation of the above-described auger compactors material may become jammed between the augers or between the augers and the walls of the chamber etc. This can cause one or both of the augers to jam and stop, which wouldtypically require manual intervention to resolve so that operation of the auger compactor may resume. To alleviate this problem, the auger compactors preferably include a control system or controller configured to control the rotation of the augers independently from each other.

[0053] A flow diagram of an exemplary form of the logic of the control system is shown in Figure 10. When the auger compactor is in an active sate, the control system is configured to monitor the current draw on each of the motors which drive the augers. In this example, a threshold current draw of 20A is set which anticipates a jammed condition of the respective augers. It will be appreciated that this threshold may be set to any desired amperage, which may depend on the application and size of the machine.

[0054] If the current draw of a motor is below the threshold, the augers are rotated in their normal operational directions by the respective motors, i.e. clockwise for the lefthand side motor and counterclockwise for the right-hand side motor.

[0055] If the current draw of a motor exceeds the threshold (representing a particular resistance against movement, e.g. caused by a material blockage), the controller is configured to stop the rotation of that motor (and therefore the respective auger), for a prescribed time period (such as around 1 second). This pause time may be adjusted as required, e.g. larger motors may require longer time periods to safely reverse rotation. The stopped motor is then rotated in the opposite direction to move the auger in the respective reverse direction, e.g. counterclockwise for the left-hand side motor and clockwise for the right-hand side motor. The reverse rotation proceeds for a prescribed period of time (for example 6 seconds, again the period can be varied as required), to attempt to clear the material causing the blockage to the respective auger. On completion of the reverse drive period, the reverse rotation is stopped for the prescribed pause time and the auger direction of movement again reversed, the resulting rotation thus reverting to the original, normal operational direction of that auger.

[0056] As will be appreciated, the stopping and reversing of each auger is realised independently of the movement of the other auger, which the applicant has found can result in a higher likelihood of clearing the material blockage than if both augers were to be simultaneously stopped and reversed. The rotation reversal will then be repeated whenever the current draw threshold is again exceeded for a particular auger.

[0057] As will be understood, the current threshold for both motors may be exceeded at the same or similar time (due, for example, to a blockage affecting movement of both augers), which would therefore result in simultaneous reversal of rotation of both augers.

[0058] By use of such a control system (with independent drive and rotation reversal of the respective augers), the auger compactor can continue shredding and compaction with one auger while a blockage affecting the other auger is cleared. Such an approach also reduces the need for manual oversight and intervention by operational staff, which also enhances operational safety.

[0059] As will be understood, the operation of the auger compactor results in crushing or shredding and thus reducing the size of the waste items prior to packing the material into a receiving volume defined by the interior of the container. The auger compactor can be paired with bin lifters, tippers, chutes, conveyors, platforms, pre-crushers, sliders, balers and bins of various different sizes. In common with other auger equipment, the auger compactor can operate continuously (rather than batch-wise), the resulting uninterrupted processing minimising the need for onsite unprocessed waste storage.

[0060] It will be appreciated that the auger compactor head and the waste compactor can be designed and built in different sizes and variants to suit the particular waste stream and site-specific requirements.

[0061] It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

Claims

CLAIMS1 . A bulk waste compaction apparatus with a material-receiving opening and an elongated trough, including: a first auger mounted to rotate in, and drive material axially lengthwise of, the elongated trough, and a second auger arranged beside the first auger and mounted to counter rotate in, and drive material axially lengthwise of, the elongated trough, wherein the elongated trough includes an outlet opening through which the material is driven by the augers, and wherein the augers each include an auger flight, the auger flights having a plurality of auger teeth projecting radially outwardly therefrom.

2. The bulk waste compaction apparatus of claim 1 , further including a controller configured to control the rotation of the augers independently of each other.

3. The bulk waste compaction apparatus of claim 2, wherein the controller is configured to stop rotation of one of the augers independently of the other.

4. The bulk waste compaction apparatus of claim 2 or claim 3, wherein the controller is configured to monitor rotation of the first and second auger.

5. The bulk waste compaction apparatus of claim 4, wherein the monitoring includes monitoring a current draw of electric motors operable to rotate the first and second augers.

6. The bulk waste compaction apparatus of claim 5, wherein the controller is configured to stop rotation of one auger when the current draw exceeds a threshold.

7. The bulk waste compaction apparatus of any one of claims 1 to 6, wherein the controller is configured to reverse rotation of one of the augers independently of the other.

8. The bulk waste compaction apparatus of claim 7, wherein the controller is configured to stop the auger rotating in the reverse direction independently of the other auger.

9. The bulk waste compaction apparatus of claim 8, wherein the controller is configured to once more reverse rotation of the reversed auger so that the auger rotates in its normal operational direction.

10. The bulk waste compaction apparatus of any one of claims 1 to 9, wherein the augers are independently driven by separate motors.11 . The bulk waste compaction apparatus of claim 10, wherein power is transmitted from a motor to the respective auger via a drive chain or gear box.

12. The bulk waste compaction apparatus of any one of claims 1 to 11 , wherein the auger teeth are disposed along the full length of the auger flights.

13. The bulk waste compaction apparatus of any one of claims 1 to 12, wherein the auger teeth are defined by a peripheral edge of each of the auger flights.

14. The bulk waste compaction apparatus of any one of claims 1 to 13, wherein the pitch of the auger flights is constant.

15. The bulk waste compaction apparatus of any one of claims 1 to 14, wherein the pitch of the augers is in a range of 300mm to 900mm, preferably around 600mm.

16. The bulk waste compaction apparatus of any one of claims 1 to 15, wherein the diameter of the auger flights tapers from the mounted end toward the opening.

17. The bulk waste compaction apparatus of any one of claims 1 to 16, wherein the diameter of the auger flights is in the range of 450mm to 1200mm, preferably around 700mm.

18. The bulk waste compaction apparatus of any one of claims 1 to 17, wherein the elongated trough is shaped to direct introduced waste material to, and contain said material in, a part of the trough adjacent to the auger flights.

19. The bulk waste compaction apparatus of any one of claims 1 to 18, further including static teeth provided on a bottom or lower surface of the trough.

20. The bulk waste compaction apparatus of any one of claims 1 to 19, further including a bulk waste container to receive material that has been compacted by the first and second augers.

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