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Title:
GLASS RECOVERY PROCESS
Document Type and Number:
WIPO Patent Application WO/2017/182810
Kind Code:
A1
Abstract:
A glass recovery process and system therefor, for recovering glass from waste material is disclosed. The process comprises the steps of: separating oversize components from the waste material to produce a first waste separate; separating magnetisable components from the first waste separate to generate a second waste separate washing the second waste separate to produce a cleaned material; partially drying at least a portion of the cleaned material; separating non-metallic and non-ferrous components from the partially dried, cleaned component, to produce a non-metallic separate; and, crushing at least a portion of the non-metallic separate.

Inventors:
JOHN, Karen (25 Heol Cefni, Morriston, Swansea West Glamorgan SA6 7EU, SA6 7EU, GB)
Application Number:
GB2017/051102
Publication Date:
October 26, 2017
Filing Date:
April 20, 2017
Export Citation:
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Assignee:
GLASS TECH RECYCLING LTD (Unit 10, Tank Farm RoadLlandarcy, Skewen West Glamorgan SA10 6EN, SA10 6EN, GB)
International Classes:
B03B9/06
Foreign References:
US20060000237A12006-01-05
US20090283018A12009-11-19
US5950936A1999-09-14
US6464082B12002-10-15
DE4300870A11994-07-21
Attorney, Agent or Firm:
DAVIES, Elliott et al. (Wynne-Jones, Laine & James LLPEssex Place,22 Rodney Road, Cheltenham Gloucestershire GL50 1JJ, GL50 1JJ, GB)
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Claims:
CLAIMS

1 . A glass recovery process for recovering glass from waste material, the process comprising the steps of:

separating oversize components from the waste material to produce a first waste separate;

applying a vacuum suction to the first waste separate to remove lightweight components to produce a second separate;

separating magnetisable components from the second waste separate to generate a third waste separate

washing the third waste separate to produce a cleaned separate;

partially drying at least a portion of the cleaned separate;

separating non-metallic and non-ferrous components from the partially dried, cleaned separate, to produce a non-metallic separate; and,

crushing at least a portion of the non-metallic separate. 2. A glass recovery process according to claim 1 , wherein the vacuum suction is generated by an impeller.

3. A glass recovery process according to claim 2, wherein the impeller is arranged to generate a low pressure proximate the first separate to draw lightweight components of the first separate to a receptacle.

4. A glass recovery process according to any preceding claim, wherein the first waste separate is produced by passing the waste material over a mesh screen so that the first waste separate comprises the component of the waste material which passes through the screen.

5. A glass recovery process according to any preceding claim, wherein the oversize components are separated to a bin or receptacle or the like.

6. A glass recovery process according to any preceding claim, wherein the third waste separate is produced by subjecting the second waste material to a magnetic field, so that magnetisable components become separated from the second waste separate. A glass recovery process according to claim 6, wherein the magnetic field is generated by a magnetisable band or belt which is arranged to pass over the second waste separate.

A glass recovery process according to any preceding claim, wherein the third waste separate is cleaned by passing the third waste separate into a bath comprising a cleaning liquid.

9. A glass recovery process according to claim 8, further comprising agitating the cleaning liquid to minimise any settlement of lighter components of the third waste separate within the bath.

10. A glass recovery process according to claim 9, further comprising removing the lighter components by extracting an upper region of the liquid within the bath.

1 1 . A glass recovery process according to claim 9 or 10, further comprising removing a heavier component of the third waste separate from the bath by lifting the heavier component from the bath.

12. A glass recovery process according to any of claims 9 to 1 1 , further comprising passing the lighter component through a filter to remove the lighter components from the cleaning liquid.

13. A glass recovery process according to claim 12, further comprising extracting the cleaning liquid from the filter and passing the extracted liquid to a settlement tank.

14. A glass recovery process according to claim 13, further comprising adding a flocculent to the settlement tank to encourage the separation of particulates from the liquid.

15. A glass recovery process according to claim 13 or 14, further comprising passing the liquid within the tank back to the bath for cleaning of further third waste separate.

16. A glass recovery process according to claim 10, further comprising passing a heavier component of the third waste separate to a vibration unit which is arranged to vibrate the heavier component to shake-off any liquid disposed upon the heavier component.

17. A glass recovery process according to claim 10, further comprising directing an air jet upon a heavier component of the third separate to remove excess liquid therefrom.

18. A glass recovery process according to any preceding claim, further comprising separating non-glass components from the non-metallic separate, to produce a substantially recovered glass component, prior to crushing.

19. A glass recovery process according to claim 1 , comprising:

separating oversize components from the waste material to produce a first waste separate, then subsequently

applying a vacuum suction to the first waste separate to remove lightweight components to produce a second separate, then subsequently

separating magnetisable components from the second waste separate to generate a third waste separate, then subsequently

washing the third waste separate to produce a cleaned separate, then subsequently partially drying at least a portion of the cleaned separate, then subsequently separating non-metallic and non-ferrous components from the partially dried, cleaned separate, to produce a non-metallic separate, and subsequently crushing at least a portion of the non-metallic separate

20. A glass recovery system for recovering glass from waste material, the assembly comprising a plurality of processing stations for collectively carrying out the process according to any preceding claim.

Description:
GLASS RECOVERY PROCESS

The present invention relates to a glass recovery process for recovering glass from waste material.

Domestic and industrial waste is typically placed in land-fill site. This waste may comprise metal and non-metallic components. We have now devised an improved method of recovering a glass component from waste material for subsequent use as an aggregate in the construction industry, for use in the production of insulation or for the production of glassware, for example.

According to a first aspect of the present invention, there is provided a glass recovery process for recovering glass from waste material, the process comprising the steps of:

separating oversize components from the waste material to produce a first waste separate;

applying a vacuum suction to the first waste separate to remove lightweight components, to produce a second separate;

separating magnetisable components from the second waste separate to generate a third waste separate;

washing the third waste separate to produce a cleaned separate;

partially drying at least a portion of the cleaned separate;

separating non-metallic components from the partially dried, cleaned separate, to produce a non-metallic separate; and,

crushing at least a portion of the non-metallic separate.

In an embodiment, the first waste separate is produced by passing the waste material over a mesh screen so that the first waste separate comprises the component of the waste material which passes through the screen. The oversize components are preferably separated to a bin or receptacle or the like.

In an embodiment, the vacuum suction is generated by an impeller. The impeller is arranged to generate a low pressure proximate the first separate to draw lightweight components of the first separate, such as fibrous components, to a receptacle.

In an embodiment, the third waste separate is produced by subjecting the second waste separate to a magnetic field, so that magnetisable components become separated from the second waste separate. The magnetic field may be generated by a magnetisable band or belt which is arranged to pass over the first waste separate. In an embodiment, the third waste separate is cleaned by passing the third waste separate into a bath comprising a cleaning liquid, such as water. The process further comprises agitating the cleaning liquid, such as via paddles, to minimise any settlement of lighter components of the third waste separate within the bath. In an embodiment, the process further comprises removing the lighter components of the third separate by extracting an upper region of the liquid within the bath. The process further comprises removing heavier components of the third waste separate from the bath by lifting the heavier components, such as through the use of the Archimedes screw principle, from the bath. The application of the vacuum suction prior to the cleaning further assists in minimising the settlement of lighter components within the bath and thus enables the cleaning liquid within the bath to be used for longer durations before it is necessary to replace/replenish the bath with fresh liquid.

In an embodiment, the process further comprises passing the lighter components from the third separate through a filter, such as sand based filter bed to remove the lighter components from the cleaning liquid. The process further comprises extracting the cleaning liquid from the filter and passing the extracted liquid to a settlement tank, such as a lamella clarifier. The process may further comprise adding a flocculent to the settlement tank to encourage the separation of particulates from the liquid, so that the particulates can settle to the bottom of the tank. The liquid within the tank may then be passed back to the bath for cleaning of further second waste separate.

The heavier components of the third waste separate are passed to a vibration unit which is arranged to vibrate the heavier components to shake-off any cleaning liquid disposed thereon. The process further comprises directing an air jet upon the heavier components to remove excess water therefrom. The air-jet preferably comprises a planar jet of air.

In an embodiment, the non-metallic separate is produced using an Eddy current separator, for example. The process may further comprise separating non-glass components from the non-metallic separate, to produce a substantially recovered glass component, prior to crushing, such as using a cone crusher. In an embodiment, the process comprises an ordered sequence of processing stages, comprising:

separating oversize components from the waste material to produce a first waste separate, then subsequently

applying a vacuum suction to the first waste separate to remove lightweight components to produce a second separate, , then subsequently separating magnetisable components from the second waste separate to generate a third waste separate, , then subsequently

washing the third waste separate to produce a cleaned separate, then subsequently partially drying at least a portion of the cleaned separate, then subsequently separating non-metallic components from the partially dried, cleaned separate, to produce a non-metallic separate, and subsequently

crushing at least a portion of the non-metallic separate.

This ordered sequence is found to produce a less contaminated recovered glass component which can be used directly in the production of glassware. According to a second aspect of the present invention, there is provided a glass recovery system for recovering glass from waste material, the system comprising a plurality of processing stations for collectively carrying out the process of the first aspect.

Whilst the invention has been described above it extends to any inventive combination of the features set out above, or in the following description, drawings or claims. For example, any features described in relation to any one aspect of the invention is understood to be disclosed also in relation to any other aspect of the invention.

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 a is a schematic illustration of a system for recovering glass from waste material according to an embodiment of the present invention, illustrating the first, second, third and fourth processing stations;

Figure 1 b is a schematic illustration of a system for recovering glass from waste material according to an embodiment of the present invention, illustrating the fifth, sixth and seventh processing stations; and, Figure 2 is a flow chart illustrating the steps associated with a glass recovery process according to an embodiment of the present invention.

Referring to figures 1 a and 1 b of the drawings, there is illustrated a glass recovery system 100 according to an embodiment of the present invention, for recovering glass from waste material 200, and is arranged to implement a glass recovery process 300 according to an embodiment of the invention, as illustrated in figure 2 of the drawings.

The system 100 comprises a hopper 101 for holding the waste material 200 to be processed and a plurality of process stations 1 10-170 for processing the waste material 200. The system 100 further comprises conveying means 102 for conveying the waste material 200 between the stations 1 10-170, as will now be described.

The hopper 101 comprises a collection bin, for example for receiving the raw waste material 200 at step 301 , and is arranged to feed the waste material onto a first conveyor belt 102a for example at step 302, which passes the waste material to a first processing station 1 10 for separating oversize components 200a from the waste 200 at step 303. The first station 1 10 comprises a mesh screen 1 1 1 and the waste material 200 is deposited upon the mesh screen 1 1 1 from the first conveyor belt 102a. The screen 1 1 1 is substantially planar, but inclined, so that components 200a of the waste which are above a threshold size, namely an aperture size within the mesh 1 1 1 , can pass over the mesh 1 1 1 and are directed into a first collection bin or bay 1 12 by a chute (not shown). The waste components 200b which are below the threshold size can pass through the mesh 1 1 1 and are directed onto a second conveyor belt 102b at step 304.

The material passed though the mesh screen 1 1 1 at step 304 comprises a first waste separate 200b and is subsequently passed to a second processing station 120 at step 305. During this processing stage, the first waste separate 200b is subject to a vacuum suction by an impeller 121 . The impeller is arranged to generate a low pressure proximate a portion of the second conveyor belt 102b to draw lightweight components, such as fibrous material (not shown) including paper and plastics, along a vacuum duct 122. The vacuum duct comprises an inlet 123 disposed proximate the second conveyor 102b and the fibrous component is drawn into the duct via the inlet, to a receptacle 124, which is arranged to store the fibrous component. The remaining heavier components of the first separate constitute a second separate 200c, which continues along the second conveyor 102b to a third processing station 130 at step 306. The third processing station 130 is arranged to separate magnetisable components

200d from the second separate 200c to generate a third separate 200e, at step 307. The third station 130 comprises a magnetisable band or belt 131 which is arranged to rotate around two longitudinally separated rollers (not shown), separately positioned either side of the second conveyor belt 102b and above the second conveyor belt 102b. The band 131 is arranged to move in a direction which is substantially transverse to the direction of the second conveyor belt 102b and as the second separate 200c passes under the rotating band 131 , magnetisable components 200d of the second separate 200c become attracted to the band 131 and carried away therewith. The magnetisable components 200d are then removed from the band 131 and collected in a second collection bin or bay 132 at step 308. The third waste separate 200e is then passed to a fourth processing station 140 at step 309 for washing. The third waste separate 200e is deposited by the second conveyor belt 102b into a bath 141 at step 310, which comprises a cleaning liquid 142, such as water. The bath 141 comprises a plurality of paddles 143 positioned therein, which are driven by drive means (not shown) to agitate the liquid 142 at step 31 1 and minimise any settlement of the third waste separate 200e at the bottom of the bath 141 . The fourth station 140 further comprises a lifting device in the form of an Archimedes screw 144. As the third separate 200e enters the bath 141 , the lighter components will rise toward the surface of the liquid 142, owing to the agitation of the liquid 142, whereas the heavier components will pass toward a lower region of the bath 141 , and can collect within a lower region of the screw lifting device 144.

The lighter components within the third separate 200e are removed from the cleaning liquid 142 by allowing the liquid within the bath 141 to flow over a weir (not shown), into a filter bed 145, such as a sand filled receptacle, at step 312. The sand 145 is arranged to remove fine particulates from the liquid 142, and the liquid is subsequently passed to a settlement tank 146 at step 313, which may include lamella clarifier, for example. A flocculent (not shown) may be added to the tank 146 at step 314 to encourage the aggregation of any remaining particulates, so that these aggregates can then settle to a lower region of the tank 146. The liquid within the tank 146 may then be recycled to the bath 141 via a ducting arrangement (not shown) at step 315, by extracting the water from an upper region of the tank 146, so that it is largely free from aggregates and small particulates.

The heavier components within the bath 141 are lifted out therefrom by rotating the screw 144 at step 316. The heavier components are deposited from an upper region of the screw 144 onto a third conveyor belt 102c, which conveys the heavier components to a fifth processing station 150 at step 317 in which the heavier components are partially dried. The third conveyor belt 102c is arranged to convey the heavier components through a vibration unit 151 associated with the fifth station 150. The vibration unit 151 is arranged to vibrate the heavier components at step 318 to remove excess liquid therefrom. In addition, the fifth processing station 150 comprises a compressed air unit 152 for directing a planar jet of air onto the heavier components at step 319, as they advance toward the air jet on the third conveyor 102c. The air jet is also arranged to remove any residual liquid disposed on the heavier components.

Upon exiting the compressed air unit 152, the partially dried, heavier components of the third waste separate 200e are separated into a non-metallic and non-ferrous component using an Eddy current separator, for example at step 320. The third conveyor belt 102c is arranged to deposit the partially dried heavier components onto a fourth conveyor belt 102d. The fourth conveyor belt 102d passes around a rotating magnetic rotor 153 disposed at distal end of the fourth conveyor belt 102d, such that as the partially dried heavier components approach the end of the fourth conveyor belt 102d, the rotating rotor 153 induces an alternating current in the non-ferrous component 200f which generates a magnetic field that opposes the magnetic field of the rotor 153 and thus results in the non- ferrous component 200f becoming thrown off the fourth conveyor belt 102d. The non-ferrous component 200f is collected in a third collection bin or bay 154 at step 321 , whereas the remaining non-metallic component 200g is captured by a fifth conveyor belt 102e at step 322, which conveys the non-metallic component 200g to a sixth processing station 160.

The sixth processing station 160 comprises a manual separation of non-glass constituents 200h from the non-metallic component 200g at step 323, as the non-metallic component 200g passes along the fifth conveyor belt 102e. At least a portion of the remaining waste 200h, which is largely glass, is subsequently passed to a seventh processing station 170 at step 324 in which the glass component is crushed in a crusher 171 , such as a cone crusher, at step 325, to reduce the size of the recovered glass to approximately 5-10mm, typically 6mm. The partial drying of the heavier component of the third separate ensures that the portion to be crushed remains partially wet, and this minimises the generation of dust during the crushing process. From the foregoing therefore, it is evident that the above described process and assembly provides for an improved recovery of glass from waste material.