GB2330094A - Sorting system - Google Patents

Abstract

A sorting system has a circular table 12 rotatable at a desired speed and has typical utility in sorting scrap metals. Scrap 40 may be deposited onto the table from a hopper and sorters 16 - 22 can be positioned around the table and are provided with bins 24 - 30 to receive material picked from the table. The table may be in the form of an annulus and the sorters positioned within the annulus. A sweeper arm 46 may be used to remove unwanted material from the table. The system may comprise a series of tables disposed as a cascade.

Description

SORTING SYSTEM The present invention relates to sorting systems and more particularly to sorting systems for scrap metal.

In known sorting systems scrap metal with impurities such as rubber is carried along a conveyor past an operator who picks out manually items that cannot be simply removed by other means, e.g. magnets for ferrous material. The operator can remove specific metals such as clean aluminium, irony cast aluminium, magnesium, zinc, brass, copper providing that the scrap is broken up into small pieces.

This system is reasonable but has the disadvantage that the scrap is only transported in front of the sorter for a very short time, dependent on the speed of the conveyor. If more efficient sorting is required then several operators can be positioned along the length of the conveyor but this requires that the conveyor be elongated, possibly 10 metres or more.

The disadvantage with this is that several operators are required to perform the sorting which is expensive in manpower terms.

It is an object of the present invention to provide a sorting system in which the operator/sorter can have several opportunities to perform the sorting operation on the scrap material.

According to the present invention there is provided a sorting system comprising a circular sorting table, the table being provided with means for rotation at a predetermined speed.

The speed of rotation may be variable.

Preferably means are provided for introducing scrap material on to the sorting table at a defined position.

The system is preferably provided with sweeper mesons for sweeping scrap material from the table.

Preferably the table rotates at a peripheral speed of 1 to 2 feet per second (0.3 to 0.6 metres/second).

In a further embodiment the table is in the shape of an annulus, sorting being carried out from within a central area of the annulus.

In a further embodiment the system comprises a series of circular sorting tables mounted in a cascade arrangement.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows diagrammatically in plan view a sorting system in accordance with the present invention; Figure 2 shows the system of Figure 1 in elevation; Figure 3 shows diagrammatically in plan view a first alternative design sorting system in accordance with the present invention; Figure 4 shows the system of Figure 3 in elevation; Figure 5 shows diagrammatically in plan view a second alternative sorting system in accordance with the present invention; and Figure 6 shows the system of Figure 5 in elevation.

With reference now to Figures 1 and 2, the sorting system 10 comprises a circular table 12 which is rotated in the direction of arrow 14, preferably at a peripheral speed of between 1 and 2 feet per second.

Operators or sorters 16,18,20,22 are positioned as shown at intervals around the table 12. In a preferred embodiment there will only be one sorter, e.g. 16, but several as shown could be accommodated dependent on the size of the sorting table.

Preferably the table 12 has a width W of 2 metres or less. This enables the sorter 16 to reach over the table to the centre.

Each sorter 16 is provided with a bin 24,26,28,30 to accommodate material sorted from the conveyor. As an example, in a mixture of aluminium brass and copper, the bin 24 could be used for brass and bin 26 for copper. Alternatively (not shown) an operator 16 could be used provided with two bins one each side of position 16 for sorting of, for example, magnesium and zinc. This could especially be so where only one operator is used.

Scrap material 40 is deposited onto table 12 by a hopper 42 which may be of the vibratory type. It is preferable to provide screening to remove small particles of soil and further screening to remove larger soil particles which may include small metal particles. The fine soil can be tipped away but the slightly larger soil and metal particles can be sent for further processing. The screening can be provided before the hopper 42 or after processing on table 12, the soil then being swept off by arm 46.

The scrap 40 falls on to an inverted cone 44 which is mounted in the centre of the table 12. The scrap therefore falls down the cone and spreads out over table 12. The scrap material continues to be carried round the table 12 and will therefore pass sorter 16 several times, allowing the sorter to pick over the material with far greater efficiency.

Once the material has been sorted to the satisfaction of the sorter 16, a sweeper arm 46 may be lowered in the direction of arrow 48 to just contact the upper surface of the table 12 thereby sweeping thZ scrap material off the table.

In the embodiment of Figure 1 the scrap material is shown as being swept into a hopper 26 but this would not be so if position 18 were in use.

In this case sweeper 46 could be positioned elsewhere.

In Figure 2 a drive motor 50 is shown supported on support means 52. Drive motor 50 will preferably include a step down gearbox (not shown) driving shaft 54 to rotate table 12 at a desired speed. A speed controller 51 may be included to enable the operator to adjust the speed of the rotating table, for example, to suit the size and/or nature of the scrap being sorted.

In an alternative embodiment, as shown in Figures 3 and 4, the table 120 is shaped as an annulus with an inner open portion 122 within which the operators 16,18,20,22 stand. Each operator is provided with a chute 124,126,128,130 to drop material picked up from table 120 into a suitable hopper 240.

In this embodiment material 40 is deposited onto table 120 by a conveyor 132. Table 120 may be driven by suitable means such as a peripheral roller 134 acting against the edge of the table. The table may be suitably suspended for rotation by bearing means such as roller bearings 136 mounted in a frame 138 or by other suitable suspension means.

A similar sweeper arm arrangement 46 may be mounted above table 120 to be operable by the operator to sweep the scrap material from the conveyor once the operator sorter has decided that the sorting has been satisfactorily completed. Again, as in Figures 1 and 2 the operator sorter has an opportunity to see the scrap material several times thereby enabling more efficient sorting.

Alternatively, a smaller sweeper arm 46' operable by the operator can be used to sweep scrap back towards the centre. A similar arm can be used in the embodiment of Figure 1 to sweep material away from the centre. The arms 46' can therefore be used to move the material on the table and to further turn the material over for sorting.

Since scrap material which is sorted to achieve a greater purity of metal is much more valuable than contaminated material, the sorting process enabled by this sorting apparatus substantially increases the value because the operator sorter can have several chances to observe the scrap material and to select correctly the desired metal from the scrap.

In a preferred embodiment in the embodiments of Figures 1,3 and 5 guards 140 may be proved to protect the operator sorter at least adjacent the sorting position. These guards 140 can be low enough so that the operator can see over them but will protect the operator sorter from getting clothing caught.

Preferably each guard 140 comprises a steel (or other suitable material) sheet 142 suitably shaped and provided with a rubber edging 144 adjacent the table.

On advantage of the arrangement of Figures 3 and 4 is that the operator/sorter stands inside the table, thereby being protected from the outside where fork lift trucks etc may pass.

With reference to Figures 5 and 6, in an alternative embodiment shown only schematically, a cascade arrangement of tables is shown.

Each table 12, 121, 1211 may be of similar design but as shown in Figure 6, each table is mounted at a height to form a cascade. In Figure 6, for clarity, hoppers are not shown and also the drive arrangements which are similar to those in Figure 1 are omitted.

In Figures 5 and 6, the scrap material is fed onto the top conveyor 12 via a vibratory hopper (not shown) as in Figure 1. The scrap is sorted by an operator 22 into a hopper 30 as in Figure 1 and when sorting is complete arm 46 is operated to sweep the scrap down to the next table 121 where it is further sorted by a second operator 221 into a hopper 301.

Similarly, scrap material on table 121 is sorted by operator sorter 121 into hopper 301. When the operator on table 121 has completed sorting arm 461 is lowered, preferably under the control of operator 121 to sweep the scrap material onto table 1211.

The operator 2211 sorts the material on table 1211 and when sorting is completed the remaining material is swept into a final hopper 3012 by sweeper arm 4611.

The advantages of the cascade system are that if too much material is on table 12 then the operator can deposit it onto table 121. The act of tipping the scrap onto table 121 will turn the scrap material uncovering further material on table 121. Similarly, for the transfer between table 121 and table 1211.

Also on each table 12,121,1211 different material may be sorted into the hoppers 30,301 and 3011.

The systems described in the above mentioned figures all have the advantage that scrap material can be picked over several times ora table thereby providing a more efficient screening system.

Claims (7)

1. CLAIMS 1. A sorting system comprising a circular sorting table, the table being provided with means for rotation at a predetermined speed.
2. 2. A sorting system as claimed in claim 1 including means for enabling the speed to be varied.
3. 3. A sorting system as claimed in claim 1 or claim 2 in which means are provided for introducing scrap material on to the sorting table at a defined position.
4. 4. A sorting system as claimed in claim 1, claim 2 or claim 3 in which the system is provided with sweeper means for sweeping scrap material from the table.
5. 5. A sorting system as claimed in any one of claims 1 to 4 in which the table rotates at a peripheral speed of 1 to 2 feet per second (0.3 to 0.6 metres/second).
6. 6. A sorting system as claimed in any of claims 1 to 5 in which the table is in the shape of an annulus, sorting being carried out from within a central area of the annulus.
7. 7. A sorting system as claimed in any one of claims 1 to 5 in which the system comprises a series of circular sorting tables mounted in a cascade arrangement.