Apparatus for recycling waste metals Cross-Reference to Related Applications

The present application claims priority from Australian Provisional Patent Application- No 2007904595 filed on 24 August 2007, the content of which is incorporated herein by reference.

Field of the Invention

This invention relates, generally, to the recycling of waste metals and, more particularly, to an apparatus for recycling waste metals. The apparatus may also be used for recovering other by-products used in the working of metals.

Background to the Invention

In the working of metals to make metal components, waste metal is generated. This waste metal, commonly referred to as "swarf, is collected and disposed of in waste metal recycling bins. However, such bins occupy an exceptionally large volume, normally the size of a car parking space.

In addition, this metal scrap is collected, without charge or payment, by metal recyclers. The metal recyclers need large vehicles to accommodate the volume of metal scrap.

Further, in the production of metal objects, coolant and other liquids are used. This coolant, if not collected at the machinery making the objects, is ducted to a drain where it can be collected. However, if the coolant or other liquids escape, they can end up in a general drainage system of premises in which the metal forming machinery is located. This has adverse environmental consequences.

Still further, these coolants can contaminate the metal waste rendering it unsuitable for recycling by metal recyclers.

Summary of the Invention

According to the invention, there is provided an apparatus for recycling waste metals, the apparatus including: a support structure; a feed hopper arranged on the support structure; a compacting station in communication with the feed hopper; a feed arrangement associated with the feed hopper for feeding the waste metals in a direction toward the compacting station; and

a delivery system arranged downstream of the compacting station for delivering compacted billets from the compacting station to a receptacle.

The support structure may comprise a support frame. Preferably, to mount the apparatus beneath machinery used in fabricating metal products, the support frame is a wheeled frame.

The feed hopper may be mounted on the frame.

The feed arrangement may comprise at least one feed conveyer. Depending on the shape of the feed hopper, the feed arrangement may comprise a plurality of feed conveyors which converge towards the compacting station. The feed conveyors may be screw conveyors. Each screw conveyor may be driven by a fluid operable drive mechanism. More particularly, the fluid operable drive mechanism may be a hydraulic motor.

The compacting station may comprise a primary stage and a secondary stage. The primary stage may be in the form of a cylinder which, in use, has a longitudinal axis arranged substantially perpendicularly relative to the direction of movement of the waste materials induced by the feed arrangement. The cylinder may contain a compacting member. The compacting member may be a further screw conveyor. Once again, the screw conveyor may be driven by a fluid operable drive mechanism. The fluid operable drive mechanism may also be a hydraulic motor. The second stage of the compacting station may comprise a cylindrical body having an inlet and an outlet, the inlet being adjacent an outlet from the cylinder of the primary stage. The cylindrical body may be arranged substantially orthogonally with respect to the longitudinal axis of the cylinder of the primary stage. The secondary stage preferably includes a billet-forming zone for the compacted waste metals, the billet forming zone being arranged toward the outlet end of the cylindrical body. The outlet of the cylindrical body may be closed off by a closure member. The closure member may be in the form a closure gate.

A compacting member for compacting the waste metals may be arranged within the billet forming zone, the compacting member preferably being reciprocally displaceable along a longitudinal axis of the cylindrical body. The compacting member may be in the form of a fluid operable ram. The ram may compact metal scrap received in the cylindrical body into a billet in the billet-forming zone.

The delivery system may communicate with the outlet of the cylindrical body. The delivery system may include a delivery element which feeds the billets ejected from the secondary stage for discharge into the receptacle.

Preferably, the apparatus includes a collection device arranged beneath the compacting station for collecting waste liquid, mixed in with the waste metals, during the compacting of the waste metals in the compacting station.

The collection device may be in the form of a collection tray which is slidably received on the support structure. A level detector may associated with the collection device. A liquid removal device may be provided for removing waste liquid from the collection device when the detector detects a predetermined quantity of waste liquid in the collection device. The liquid removal device may be a pump. The liquid removal device may direct the waste liquid to a site for recycling or re-use. . As indicated above, the apparatus is, generally, hydraulically operable. Thus, the apparatus may include a reservoir of hydraulic fluid, hydraulic valves for controlling distribution of the hydraulic fluid and an hydraulic fluid cooling arrangement all carried on the support structure.

The apparatus may further include a controller for controlling operation of the apparatus. The control mechanism may be in the form of a programmable logic controller (PLC) or similar device.

A drier is preferably provided downstream of the compacting station for drying the compacted billets. A low pressure inducing device is preferably provided downstream of the compacting station for assisting in removing residual fluid from the compacted billets.

Brief Description of Drawings

Preferred embodiments of the invention are now described by way of example with reference to the accompanying drawings in which:- Fig. 1 shows a three dimensional view of an embodiment of an apparatus for recycling waste metals;

Fig. 2 shows a side view of the apparatus;

Fig. 3 shows a three dimensional view of a part of the apparatus of Figs. 1 and 2; Fig, 4 shows a plan view of the part; Fig. 5 shows a side view of the part;

Fig. 6 shows a bottom view of the part;

Fig. 7 shows a three dimensional view of a second embodiment of an apparatus for recycling waste materials;

Fig, 8 shows a plan view of the apparatus of Fig. 7; Fig. 9 shows a first side view of the apparatus of Fig. 7;

Fig. 10 shows an opposite side view of the apparatus of Fig. 7;

Fig. 1 1 shows an first end view of the apparatus of Fig. 7; and Fig. 12 shows an opposite end view of the apparatus of Fig. 7.

Detailed Description of Exemplary Embodiments In Figs. 1-6 of the drawings, reference numeral 10 generally designates a first embodiment of an apparatus for recycling waste metals. The apparatus 10 includes a support structure in the form of a support frame 12. A feed hopper, in which waste metal to be recycled is receivable, is mounted on the support frame 12. A feed arrangement 16 (Figs. 3 and 4) is arranged in the feed hopper 14. As indicated above, the waste metal is commonly referred to as swarf and will be referred to as such below. A compacting station 18 is arranged downstream of a discharge opening 20 (Fig. 3) of the feed hopper 14. A delivery system, including a delivery conduit 22, is in communication with a discharge opening of the compacting station 18 for delivering compacted billets from the compacting station 18 to a receptacle (not shown). Preferably, the apparatus 10 further includes a collection device in the form of a collection tray removably mounted on the support frame 12 for enabling liquid waste, such as coolant, mixed in with the swarf to be collected for recycling or re-use.

In the illustrated embodiment, the feed hopper 14 is pentagonal when viewed in plan having sides of uneven length. The feed arrangement 16 comprises a pair of feed conveyors in the form of screw conveyors 26. The screw conveyors 26 are so arranged in the feed hopper 14 to converge towards the discharge opening 20 of the feed hopper 14 as illustrated most clearly in Fig. 4 of the drawings. It will be appreciated that the feed hopper 14 could have shapes other than pentagonal when viewed in plan.

Each screw conveyor 26 is driven by a fluid operable drive mechanism, more particularly, a hydraulic motor 28. The hydraulic motors 28 are mounted on a wall 30 of the feed hopper 14.

The compacting station 18 comprises a primary stage 32 and a secondary stage 34. The primary stage 32 comprises a cylinder 36 arranged generally perpendicularly to a rotational axis of each screw conveyor 26 of the feed arrangement 16. In use, the screw conveyors 26 of the feed arrangement are substantially horizontally disposed. Thus, the cylinder 36 is substantially vertically disposed. The cylinder 36 accommodates a further feed conveyor in the form of a screw conveyor 38 (Fig. 3). Once again, the screw conveyor 38 is driven by a fluid operable drive mechanism in the form of a hydraulic motor 40. A discharge opening of the cylinder 36 is in communication with the secondary stage 34. The secondary stage 34 comprises a cylindrical body member 42 having a

billet forming zone 44 arranged at a downstream end of the body member 42. An outlet opening of the billet forming zone 44 is closed off by a movable closure member in the form of a gate 46.

A compacting member in the form of a hydraulic ram 48 is received in an upstream end of the cylindrical body member 42. , The hydraulic ram 48 serves to compact the swarf into billets in the billet forming zone 44.

The outlet opening of the billet forming zone 44 is in communication with an inlet opening of the conduit 22. A billet 50 formed in the billet forming zone 44 is ejected from the billet forming zone 44 under the effect of the hydraulic ram 48 and is fed into the inlet opening of the conduit 22. As a billet 50 is driven into the conduit 22, billets 50 already in the conduit 22 are urged up the conduit 22 and are eventually ejected through an ejection opening 52 into a receptacle (not shown) arranged alongside the conduit 22.

The gate 46 is hydraulically controlled via hydraulic drive members 54 to be displaced into its open position or its closed position, as the case may be. Thus, once a billet 50 has been formed in the billet forming zone 44, the relevant hydraulic drive member 54 opens the gate 46 to allow ejection of the billet 50 from the billet forming zone 44.

The apparatus 10 further includes a hydraulic fluid reservoir 58 and a hydraulic filter 60 mounted on an electric control motor 62. The motor 62 drives the hydraulic motors 28 and 40, the hydraulic ram 48 and the hydraulic drive members 54. The hydraulic circuit includes a hydraulic fluid cooling arrangement 64 mounted on the support frame 12.

The apparatus 10 includes a controller in the form of a programmable logic controller (PLC) 66, including safety interlock circuitry, mounted on the support frame 12.

A level detection system or switch (not shown) is mounted in the collection tray 24. A liquid removal device, in the form of a scavenge pump 68, is mounted on the wall 30 of the feed hopper 14. When the level of waste coolant in the collection tray 24 exceeds a predetermined level as detected by the level detection switch, the PLC 66 operates the pump 68 for draining the coolant from the collection tray 24 and feeding the liquid coolant to a site for recycling or re-use.

Thus, in use, swarf is deposited into the feed hopper 14. This may occur automatically from the metal working machinery below which the apparatus 10 is positioned or manually. It is to be noted that the support frame 12 supports a plurality

of wheels 70 by means of which the apparatus 10 can be manoeuvred into position at the machinery.

Regardless of the manner in which the swarf is received in the feed hopper, when a sufficient quantity of swarf is contained within the feed hopper 14, the hydraulic motors 28 are operated. The screw conveyors 26 convey the swarf into the primary stage 32 of the compacting station 18. In the primary stage 32, the screw conveyor 38 is operated under the control of the hydraulic motor 40 to slightly compact the swarf. From there, the swarf is transported by the screw conveyor 38 into the secondary stage 34, more particularly, the cylindrical body member 42 of the secondary stage 34.

When the cylindrical body member 42 of the secondary stage 34 of the compacting station 18 contains a sufficient quantity of compacted swarf, the hydraulic ram 48 is operated and is driven in the direction of arrow 72 (Fig. 5). The swarf is urged into the billet forming zone 44 under the action of the ram 48. The swarf is compacted into a billet in the billet forming zone 44. Once a sufficient pressure, for example, about 40 to 50 tonnes has been exerted on the swarf to form the billet 50, the appropriate hydraulic drive member 54 is operated to open the gate 46. The hydraulic ram 48 is then further operated in the direction of arrow 72 to eject the billet 50 from the billet forming zone 44 into the conduit 22. The hydraulic ram 48 is withdrawn to await the next load of swarf to be compacted.

When the gate 46 opens, any liquid coolant mixed with the waste metal runs out of the billet forming zone 44 and collects in the collection tray 24. As indicated above, the collection tray 24 has a level detection switch so that, when the level of coolant in the tray 24 reaches a predetermined level, the PLC 66 operates the pump 68 to extract the coolant from the tray 24 for delivery to a recycling site or for re-use.

A second embodiment is shown in Figs. 7-12 of the drawings, where reference numeral 100 generally designates an apparatus for recycling swarf. The apparatus 100 includes a support structure in the form of a support frame 120. A feed hopper 140, in which swarf to be recycled is receivable, is mounted on the support frame 120. A feed arrangement 160 (Figs. 7 and 8) is arranged in the feed hopper 140.

A compacting station 180 is arranged downstream of a discharge opening 200 (Fig. 7) of the feed hopper 140. A delivery system 220 is in communication with a discharge opening of the compacting station 180 for delivering compacted billets from the compacting station 180 to a receptacle (not shown). The delivery system 220 includes a billet ratchet lock 222, a tensioning assembly 224 and an elevator chute 226.

The billet ratchet lock 222 holds the billets in place on the elevator chute 226 and prevents the billets from sliding back into the compacting station 18 under gravity.

Preferably, the apparatus further includes a collection device in the form of a collection tray removably mounted on the support frame 120 for enabling liquid waste, such as coolant, mixed in with the swarf to be collected for recycling or re-use.

In the illustrated embodiment, the feed hopper 140 is pentagonal when viewed in plan having sides of uneven length. The feed arrangement 160 comprises a pair of feed conveyors in the form of screw conveyors 260, which move the swarf from the hopper 140 in a direction toward the compacting station 180. The screw conveyors 260 are so arranged in the feed hopper 140 to converge towards the discharge opening 200 of the feed hopper 140 as illustrated most clearly in Fig. 8 of the drawings. Again, it will be appreciated that the feed hopper 140 could have shapes other than pentagonal when viewed in plan.

Each screw conveyor 260 is driven by a fluid operable drive mechanism, more particularly, a hydraulic motor 280. The hydraulic motors 280 are mounted on a wall 300 of the feed hopper 140.

The compacting station 180 comprises a primary stage 320 and a secondary stage 340. The primary stage 320 comprises a cylinder (not shown) arranged generally perpendicularly to the direction of movement of swarf induced by the screw conveyors 260. In use, the screw conveyors 260 of the feed arrangement are substantially horizontally disposed. Thus, the cylinder is substantially vertically disposed. The cylinder accommodates a further feed conveyor in the form of a screw conveyor 380 (Figs. 7, 9 and 10). Once again, the screw conveyor 380 is driven by a fluid operable drive mechanism in the form of a hydraulic motor 400. A discharge opening of the cylinder is in communication with the secondary stage 340. The secondary stage 340 comprises a cylindrical body 420 having a billet forming zone 440 arranged downstream of an inlet of the cylindrical body 420. The inlet of the cylindrical body 420 is located adjacent an outlet of the cylinder of the primary stage 320. An outlet opening of the billet forming zone 440 is closed off by a moveable closure member in the form of a gate 460.

A compacting member in the form of a hydraulic ram 480 is reciprocable within the cylindrical body 420. The hydraulic ram 480 serves to compact the swarf into billets in the billet forming zone 440.

The outlet opening of the billet forming zone 440 is in communication with an inlet of the delivery system 220. A billet 500 formed in the billet forming zone 440 is ejected from the billet forming zone 440 under the effect of the hydraulic ram 480 and

is fed into the inlet of the delivery system 220. As a billet 500 is driven into the delivery system 220, billets 500 already in the delivery system 220 are urged up the elevator chute 226 and eventually ejected through an ejection opening 520 into a receptacle (not shown) arranged downstream of the delivery system 220. A drier 524 for drying the billets 500, and evacuation chamber 526 for applying suction to the billets 500 to facilitate removal of residual fluid, is provided between the ejection opening 520 of the delivery system 220 and the receptacle (not shown).

The gate 460 is hydraulically controlled via hydraulic drive members 540 to be displaced into its open position or its closed position, as the case may be. Thus, once a billet 500 has been formed in the billet forming zone 440, the relevant hydraulic drive member 540 opens the gate 460 to allow ejection of the billet 500 from the billet forming zone 440.

The apparatus 100 also includes similar hydraulic and control components as described in the first embodiment above with reference to Figs. 1 and 2. Operation of apparatus 100 of the second embodiment is similar to that described above with reference to Figs. 1-6. However, the apparatus 100 also includes a swarf input system including a hydraulically operated docking station 820 for receiving feed swarf in a standard 200 litre (44 gallon) drum 800. The docking station 820 is hydraulically driven to raise and rotate the drum 800 relative to the feed hopper 140 to discharge the feed swarf into the hopper 140 under gravity.

The apparatus 100 further includes a sequence valve 700 for diverting hydraulic fluid from the hydraulic motor 280 to the hydraulic motor 400 when sufficient swarf has accumulated in the primary stage 320 to apply a predetermined load to the screw conveyors 260. The predetermined load is selected to facilitate delivery of a consistent amount of swarf to the primary stage 320 to, in turn, facilitate consistent billet sizes after compaction.

The apparatus 100 also includes a dump valve 702 for releasing hydraulic pressure applied to the hydraulic ram 480 when a sufficient compaction pressure, of approximately 40 to 50 tonnes, has been exerted on the swarf to form a billet. However, it will be appreciated that higher or lower compaction pressures can be applied in other embodiments by varying the pressure applied to the hydraulic ram 480, and adjusting the actuating pressure of the dump valve 702, to produce billets of a desired density. The dump valve 702 facilitates the operating longevity of the apparatus 100 and its hydraulic components. When a billet 500 reaches the top of the elevator chute 226, it is transferred into the billet drier 524 and is acted on by the evacuation chamber 526. The billet drier 524

includes an induction heater, which is configured to expel residual fluid from the billet 500 in conjunction with suction applied by the evacuation chamber 526. The removed fluid is drained from the evacuation chamber 526 into a separate holding container (not shown), or can be returned to the tray 240. It is therefore an advantage of the invention that an apparatus 10, 100 is provided which compacts swarf into billets 50, 500 which are able to be handled easily. While metal recyclers do not generally make payment for waste metal in swarf form, they will pay up to $300 per tonne for scrap steel. Additionally, liquid coolant is also reclaimed for recycling and or re-use. With the pressures generated by the hydraulic ram 48, this liquid coolant is expelled from the billet 50, 500 thus rendering it more suitable and economically viable for recycling. Thus, an apparatus 10, 100 is provided which, the applicant believes, will be environmentally beneficial as well as economically beneficial. Still further, due to the fact that the swarf is compressed into small billets, the need for large metal recycling bins is obviated. It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.