GB2341872A

GB2341872A - Enclosed processing system

Info

Publication number: GB2341872A
Application number: GB9816048A
Authority: GB
Inventors: Michael Pownall
Original assignee: J Mcintyre
Current assignee: J Mcintyre
Priority date: 1998-07-24
Filing date: 1998-07-24
Publication date: 2000-03-29
Anticipated expiration: 2018-07-24
Also published as: GB9816048D0; GB2341872B

Abstract

Apparatus and method for pressing a skull comprising aluminium, aluminium dross and other impurities without pollution comprises a container within which is enclosed a milling machine 20, sieving apparatus, magnetic separator 22, charging machine and a rotary furnace 26.

Description

2341872 ENCLOSED PROCESSING SYSTE The present invention relates to an

enclosed processing system and more particularly to an enclosed processing system for processing skulls 5 produced by a dross press.

Skulls produced by a dross press, such as described in copending patent applications W096132513, W096132514 and W096132515 to the same applicant comprise relatively large pieces of material. They consist 10 of many different types of material, typically pure metal (e.g. aluminium) and other residue.

For the purposes of the resent invention the metal will be assumed to be aluminium which will normally be the case but other non-ferrous is metals could be similarly processed.

The skull therefore normally comprises a mixture of pure metal trapped in, or attached to, the skull and also residue which is usually extremely dirty material. Even moving a skull usually creates dust 20 pollution.

The present invention has for its object to provide an apparatus and method for processing the skull to produce pure aluminium and also preferably ferrous scrap, dust fractions, dust and fine fractions and also 25 grit fractions, all of which can be further processed.

The apparatus comprises a sealed unit which contains all pollution.

1 According to the present invention there is provided an apparatus for processing skulls produced by a dross press, said apparatus comprising milling means for breaking a skull into fractions, magnetic separation means attached to an outlet of the milling means for extracting ferrous material from said fractions to produce a residual fraction, transfer means for transferring the residual fraction into a rotary furnace and tapping means for tapping molten aluminium from said rotary furnace, said apparatus being contained within a substantially airtight container to thereby contain any dust or other particles produced during processing within said container.

Preferably the milling means comprises a rotating device, said rotating device having means for breaking the skull into fractions and means for transporting the fractions from an input port which receives a skull or part skull to an output port.

Preferably the milling means also comprises means for sieving the skull fractions into dust, dust and fines, grit and includes means for storing each fraction.

Preferably a charging machine is interposed between the magnetic separation means and the rotary furnace, said charging machine being movable to enable said furnace to be charged and to enable said furnace to be sealed by a moveable furnace door.

Preferably said furnace is pivoted from a first charging position to a second position in which the furnace may be tapped.

2 The present invention also provides a method for processing a skull comprising milling the skull in a rotary mill into small fractions, removing ferrous material from the small fractions to form non-ferrous fractions, transferring said non-ferrous fractions via a transfer means into a rotary furnace, all said steps being carried out within a substantially airtight container.

The present invention will now be described, by way of example with reference to the accompanying drawings in which Figure 1 shows diagrammatically the apparatus of the present invention; Figure 2 shows the apparatus of Figure 1 showing diagrammatically the inner components of the system; Figure 3 shows a flow diagram of a simplified method; Figure 4 shows a flow diagram of a more complex method; Figure 5 shows in side elevation a rotary and tilting furnace for the apparatus of Figure 1; and Figure 6 shows the furnace of Figure 5 in plan view.

With reference now to the figures, the system apparatus and method will be described with reference to processing of aluminium skulls but other types of skull may be processed.

The apparatus in Figure 1 comprises a generally totally enclosed large box/container 10 which may, in fact, be a purpose built permanent building but is preferably a portable container either whole or possible in prefabricated portions which may be assembled on site.

3 The container 10 includes an entrance 12 (shown dotted) for insertion of a skull 14 and an exit 16 for exit of molten aluminium into a suitable container 18. Both the entrance 12 and exit 16 are normally sealed by suitable flaps 12', 16' which will normally be sealed except when a new skull is introduced (12') or when pure aluminium is tapped off (16'). Other alternative arrangements are possible, as shown in Figure 2, in which a first aluminium holding bath is included within the contain 10 in which case exit 16 may be dispensed with. A plurality of doors/hatches 120,122,124 are provided in one or more sides of container 10 in order to be able to extract dust, fines, grit etc as described with reference to Figure 2. Arc exhaust flue outlet 126 is provided which is connected to a fine purification plant (not shown).

In operation the skull 14 is inserted into container 10 and pure aluminium, dust, fines and grit are extracted from the apparatus. No dust or other exhaust gases are allowed into the atmosphere.

With reference to Figure 2, the apparatus comprises a milling apparatus 20 which rotates, as shown in the direction of arrows 202,204.

That is to say apparatus 20 can be rotated in both directions to enable it to both mill the skull (break the skull into fractions) and also to controllably transport the milled fractions along the mill in the direction of arrow 206.

A magnetic separator unit 22 comprising a magnet section 222 and a suitable control and/or conveyor section 224 is situated at the end of the mill 20. The magnetic extraction unit 22 may be of conventional design, including, for example, a rotary belt but is shown only diagrammatically in Figure 2.

4 At the end of the magnetic separator 22 a charging unit 24 is preferably situated. This charging unit 24 may be moveable either in the vertical or horizontal directions, as indicated by arrows 242,244.

The charging unit 24 is operative to charge a rotary furnace 26 which is described in greater detail in Figures 5 and 6.

In Figure 2 rotary furnace 26 is shown in three positions, two of which 262,264 are shown dotted. These are exemplary positions for the purposes of explaining the present invention and other arrangements may be seen to be possible.

In position 26 the furnace is shown in ftX outline and is being charged by charger 24. The furnace door Cid) 266 is shown fully open on lever mechanisms 2662,2664. The levers and door may be hydraulically operated by hydraulic cylinders (not shown).

The furnace in position 264 is shown with the door 266 closed and in this position the rotary furnace functions to rotate and melt the aluminium. The furnace may be then tilted to position 262 and door 266 partially (or fully) opened to allow molten aluminium to be tapped into a suitable holding bath 28. This bath 28 may be equipped with a further tapping arrangement 282 which will allow aluminium to be extracted from the contain 10 without opening any hatches. Alternatively, hatch 124 may be opened to remove both 28.

Other bins 284,286,288 are preferably situated under mill 20.

These may be used to receive the sieved contents of mill 20 as follows.

Bin 284 will receive dust generated on first milling of skull 14. Bin 286 will receive dust and fines generated as the skull is further milled. Bin 288 will receive grit. A further bin 290 for magnetic separator 22 may be situated behind bin 288 and is shown dotted.

Each bin 284,286,290 may be removed from contain 10 via suitable hatches 120,124, preferably when the mill 20 is stationary so that there is no appreciable dust within container 10 which may escape to atmosphere when a hatch is opened.

The contents of each bin 284,286,288,290 are individually saleable, especially the contents of bins 288 and 290 since these will comprise ferrous material (290) and aluminium rich material 288. The material left which enters charging device 24 therefore comprises very rich aluminium material and thus rotary furnace 26 may be relatively small and also relatively efficient. As described, mill 20 preferably comprises an elongate barrel mill with guidance means 208, shown diagrammatically. By rotating the mill at various speeds and in the two directions, the skull can be initially broken up to release dust at the left-hand end and then the contents can be moved to the centre for further milling to smaller sizes which will release a certain amount of fines, and further dust into bin 286.

Further rotation of mill 20 will move the contents to the right-hand end where further grit will be generated which may either be fed into charger 24 or in this preferred embodiment is allowed to fall into further bin 288 through a coarser sieve 209.

The process steps are described briefly with respect to Figure 3. The skull 230 is fed to mill 231 where dust, fines and grit 232,233,234 are 6 produced at the various locations along the mill which are variously sieved 235. A magnetic separation step 236 is followed by a charging step 237. This charges rotary furnace 238 and furnace step 238 provides liquid aluminium which is tapped off in step 239.

A preferred example of the process is described in Figure 4. The skull 14 is fed (400) into rotary mill 401. Dust, fines and grit are created and sieved 402,403,404,405,406,407.

The residue 408 is fed to a magnetic separator 409 and to a charger 4 10. The furnace door is then opened 411, the furnace moved to a charging position 412. The charging machine is positioned to charge the furnace 413. (These steps could be modified in that if the charging machine is positioned next to the mill 20 and the charging machine is moveable then the rotary furnace door could be opened from a normal rotary position). The charging machine is removed 414, the flimace pivoted to an operating position 415 and the door closed 416.

The furnace is rotated 417 for a defined period. The furnace is then pivoted to a tapping position 418, the furnace door opened 419 and the furnace tilted to tap out the liquid aluminium 420. Surplus dust may be skimmed of the surface 421 but in a preferred embodiment the tappi may be performed below the surface of the furnace, leaving a residual layer for heat retention.

The furnace door is then closed 422 and the furnace returned to an operating (rotating) position 423 ready for further charging.

7 The furnace 26 is shown in further detail in figures 5 and 6. The door 266 and levers 2662, 2664 are as shown in Figure 2.

The pivot 266 and rotating gear driver 2668 are shown in figure 4 5 enabling the furnace to be pivoted and rotated. A rear bearing housing 2700 supports the furnace on a frame 2702.

Drive motors 2708 may rotate the furnace and a further motor and gearbox unit 2710 may cause the furnace to pivot about 2666 via coupling 102712.

The furnace may be supplied with suitable fuel via a burner 2714 when in its rotating position. The furnace stands on a base 2716.

The apparatus and method enables a skull composed of extremely dirt components to be processed without any pollution.

The whole process may be carried out automatically or if manual input is required the positioning/actuation of various components may be 20 accomplished via suitable portholes 100 in the container walls.

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Claims

1. An apparatus for processing skulls produced by a dross press, said apparatus comprising milling means for breaking a skull into fractions, magnetic separation means attached to an outlet of the milling means for extracting ferrous material from said fractions to produce a residual fraction, transfer means for transferring the residual fraction into a rotary furnace and tapping means for tapping molten aluminium from said rotary furnace, said apparatus being contained within a substantially airtight container to thereby contain any dust or other particles produced during processing within said container.

2. Apparatus as claimed in claim 1 in which the milling means comprises a rotating device, said rotating device having means for breaking the skull into fractions and means for transporting the fractions from an input port which receives a skull or part skull to an output port.

3. Apparatus as claimed in claim 2 in which the milling means also comprises means for sieving the skull fractions into dust, dust and grit, grit and includes means for storing each fraction.

4. Apparatus as claimed in claim 3 in which a charging machine is interposed between the magnetic separation means and the rotary furnace, said charging machine being movable to enable said furnace to be changed and to enable said furnace to be sealed by a moveable ftumce door.

5. Apparatus as claimed in claim 4 in which said furnace is pivoted from a first charging position to a second position in which the furnace may be tapped.

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6. A method for processing a skull comprising milling the skull in a rotary mill into small fractions, removing ferrous material from the small fractions to form non-ferrous fractions, transferring said non- ferrous S fractions via a transfer means into a rotary furnace, all said steps being carried out within a substantially airtight container.