GB2355981A - A Glass Recycling Apparatus - Google Patents

Abstract

A glass recycling apparatus comprises a trough (20) with a base floor (21) and an upper floor (22) spaced apart from the base floor. Cooling water inlet (25) and outlet (26) are used for the recirculation of water within the trough. A drag-chain conveyor (30) which has transverse scraper blades mounted between chains which scraper blades project above and below the chains is fed over the upper floor (22) pulling glass away from glass inlets (9) across the trough (20) and then down onto the lower floor (21) where the drag chain conveyor (30) pulls the glass towards a glass outlet hopper (10) Glass crushers are preferably sited in the glass inlets (9) and glass crushers may be sited around the manufacturing plant and further glass crushers may be sited adjacent the outlet hopper (10). The glass crushers are preferably rotating of the hammer mill type. In operation any hot glass on being delivered into the trough (20) will shatter, or if not shatter will at least have its crystalline structure altered which will facilitate further crushing.

Description

2355981 "A Glass Recycling Apparatus" The present invention relates to a

glass recycling apparatus for waste glass produced at least one station in a glass manufacturing plant.

Conventionally in glass manufacturing plants there is often a considerable amount of waste produced. A product can suffer from distortion for example during the manufacturing process or have a contamination or other manufacturing defect which can occur not alone during the normal running of the manufacturing process, but particularly at start up and also at change over from one product to another. Indeed the defect can be caused by slight variations in the raw materials, or indeed by any defect in the machinery itself. Conventionally what happens is that the defective glass is ejected from the production line, often by air jets and is then delivered down a chute through the floor on which the equipment is stored to a basement beneath where it is left unfit cool enough to be removed. Generally this is by means of a loading shovel or other materials handling device such as a conveyor.

In such glass manufacturing plants, there are usually a series of glass crushers provided. Quite often such glass crushers are of the so-called hammer mill type, though not exclusively so. Such a glass crusher comprises a hopper having front rear and side walls, the side walls mounting a rotatable shaft carrying a plurality of axially spaced apart sets of circurnfrentially arranged flail-like hammers, the hopper having an open-mouthed inlet and a discharge oubet below the shaft.

A. further problem arises in the manufacture of flat and plate glass as the manufacturing process always requires that the plates of glass be trimmed to a specific width and size. These trimmings can be large strips of glass of indefinite length and variable width up to 300 to 400 mm. These are exceedingly difficult to break not alone because of the abrasive properties of glass, particularly when it is plate, but also because of the fact that they come off the machinery in strips of glass of varying widths and lengths. Most are too long to fit into conventional crushers.

Subsequent to collecting the waste glass it is recycled. However, this is not by any means safisfactory. The problem is that the glass collected is of varying size and thus when it is subsequently handled there are considerable problems in crushing the glass and sizing it generally. Also there is a considerable waiting time as the glass is often hot and it is not possible, as would be desirable, to immediately recycle the glass.

One of the major problems is thus the handling of hot waste glass products. While not necessarily all the waste glass produced in a typical glass manufacturing plant Will be hot but at least one station will always produce waste glass which is hot This may even be from a furnace of imperfectly formed glass. Everything must be done to recycle the glass as quickly as possible and also to remove the hot glass which is a source of hazard in the working place.

One can readily appreciated that where a plant produces products having various colours that it is of little use to have crushed waste glass of a particular colour when the production of product using that colour of glass has ceased. Further, there is a need to have the glass in as small pieces as possible for subsequent recycling, therefore everything should be done to have the glass break naturally and thus obviate subsequent crushing.

In any event a glass crusher is almost certainly always required and conventional glass crushers suffer from a number of disadvantages. Firstly, they often cannot be easify adjusted to handle varying size of waste and secondly, particularly for harnmer mill types, they can be difficult to maintain in that access to the hammers can be difficult.

The present invention is directed towards overcoming these problems and providing a more efficient and safer way of recycling glass from a manufacturing system.

Statements of Invention

According to the invention there is provided a glass recycling apparatus for waste glass produced at a number of stations in a glass manufacturing plant, some of which glass maybe hot comprising:

an elongate cooling water containing trough having a base floor and an upper floor spaced above and apart from the base floor within the trough; a glass inlet above the upper floor; a liquid passageway down through the trough from above to below the upper floor; a drag conveyor encompassing the upper floor and compriising an endless belt formed from a plurality of transversely arranged spaced apart scraper blades mounted on and projecting above and below endless flexible connectors the scraper blades being led across the upper floor and beneath it across the lower floor in the opposite direction to a glas's outlet; conveying means for delivering waste glass from the station to the glass inlet; and glass crushers for the waste glass.

The advantage of this is that now the glass which is cooled can be handled immediately and there is no delay between, when necessary, the rejection of the glass and the recycling of it. This can be particularly important as will be appreciated with coloured glass. A further advantage is that it reduces the amount of waste glass stored on the premises and a further advantage is that because the hot glasses are delivered into the trough, which contains cooling water, the glass will often shatter on delivery into the trough but in any case whether it shatters or not the rapid cooling of the glass alters the crystalline structure of the waste glass and this in turn facilitates the subsequent crushing of the glass. Thus even If the glass is not very hot the cooling will have a beneficial effect.

A further advantage of the invenbon is that by having this particular construction of drag conveyor in combination with a spaced apart upper floor it is possible to have relatively widely spaced inlets along the trough and at the same time get sufficient 4 cooling of the glass without the necessity of providing an extremely long trough.

Spacing the inlets apart will prevent the build up of glass at any particular place in the trough and will avoid the jamming of the trough and consequent damage to the trough. Further the drag conveyor pulls the glass back across the trough and ensures that effectively the capacity of the trough is doubled and the glass can be handled efficiently.

In one embodiment of the invention the scraper blades are spaced apart from the floors. By spacing the scraper blades apart from the floors it is possible to reduce the wear on the floors since the glass will wear against other glass and will not thus abrade the floors. This reduces the wear on the floors, although it does increase the power requirements since generally it is easier to scrape glass from what are flat floors than to scrape glass along other glass which will of its nature provide a greater resistance to the drag conveyor.

Ideally there is provided a plurality of waste glass inlets longitudinally arranged along the trough above the upper floor. The advantage of this is mentioned above.

Ideally the base floor of the trough inclines upwardly to the glass outlet therefore the glass will be removed out of the trough in an efficient way.

A water recycling pump for the trough may be provided and this is useful since it will ensure that if there is a flow of water, this will further facilitate the cooling of the glass.

In one embodiment of the invention the glass crusher comprises a pair of contrarotating crusher rollers which ideally carry outwardly projecting hammers which are preferably pivotally mounted flail-like hammers. An advantage of this is that the flails can be relatively easily removed and the type of crusher is parficularly suitable for glass which is relatively fragile.

In another embodiment of the invention the glass crusher comprises: a hopper having front rear and side walls, the side walls mounting a rotatable shaft carrying a plurality of axially spaced sets of circumfrentially arranged flail-like hammers, the hopper having an open mouthed inlet and discharge outlet below the shaft in which portion of the front wall and portion of each of the two side walls connected thereto is pivotally mounted on the hopper. The advantage of this construction is that the hammers can be relatively easily accessed and that the crusher can be easily cleared of any jam such as might occur from an overload of glass into the hopper, or, alternatively the hammers can be accessed for maintenance.

To facilitate maintenance ideally the portions of the front and side walls define part of the hopper inlet and extend to adjacent the shaft.

In another embodiment of the invention with this crusher the front wall carries a pivotally mounted wear plate opposite the hammers defining a passageway for glass therebetween and adjustment means for moving the wear plate towaeds and away from the shaft to vary the size of the passageway and preferably the shaft has fast thereon end and intermediate plates carrying a plurality of circurriferentially arranged pivot bars each bar carrying in turn longitudinally arranged pivotally mounted hammers. These are particularly suitable constructions of crusher which are efficient in use.

In another embodiment of the invention the crusher is in the form of a glass breaker comprising:

an elongate hopper, having a pair of side walls and facing end walls; a shaft rotatably mounted between the end walls; a plurality of radially arranged hammers mounted on the shaft; and a plurality of spaced apart glass support bars mounted between the side walls defining slots through which the hammers project on rotation of the shaft.

This particular form of crusher is suited for elongate pieces of glass such as, for example, plate or flat glass that might have been cut to size during the glass manufacturing process. Considerable difficulty has been experienced in feeding such glass into conventional crushers as the lengths of the glass tend to jam within the mouth of the inlet hoppers and in any case are very difficult to handle. Such a crusher is particularly suited as mentioned for plate glass but can be used for any elongate pieces of glass that might be produced such as by extrusion.

Ideally the hammers are mounted in pairs on the shaft and are diametrically spaced apart around the shaft.

In this latter embodiment preferably the hammer in alternate pairs of hammers along the shaft are offset by 900 from each other. This arrangement is particularly suitable for lengths of glass in that the glass will be alternately impacted on by the hammers and this will further break the glass.

Such hammers vAll require constant maintenance and thus ideally each hammer is mounted on a half cylinder for connecting to another half cylinder to form a shaft protecting sleeve on a least one side of the hammer and in which the sleeve is mounted on each side of the hammer.

In certain instances the glass crushers may be mounted adjacent the portion of the apparatus where the actual waste is produced or alternatively may be mounted adjacent the glass inlet to the trough. By mounting the glass crusher adjacent the glass inlet to the trough, the glass can be delivered into the trough in a size suitable for handling by the drag conveyor. When, however, the glass has been suitably cooled in the trough it is often advantageous that a glass crusher be mounted adjacent the glass outlet of the trough so that the glass is in suitable form for subsequent recycling.

Detailgd Description of the InventlQn

The invention will be more clearly understood from the following descOption of some embodiments thereof given by way of example only with reference to the accompany drawings in which:

7 Fig. 1 is a layout of a typical glass manufacturing plant according to the invention, Fig. 2 is a side view of a glass recycling apparatus, Figs. 3 and 4 are enlarged side views of portion of the apparatus of Fig. 2, Fig. 5 is an enlarged side view of another portion of the apparatus, 10 Fig. 6 is a sectional view of a glass inlet used in the apparatus of Figs. 3 to 5. Fig. 7 is a typical sectional view of a crusher according to the invention, 15 Fig. 8 is a sectional view similar to Fig. 7, showing by interrupted lines operation of the glass crusher, Fig. 9 is a front view of a shaft and flail-like hammers forming part of the.20 crusher, Fig. 10 is an end view of the shaft of Fig. S.

Fig. 11 is an end view of a plate for mounting on the shaft of Fig. S. 25 Fig. 12 is a plan view of a glass breaker according to the invention, Fig. 13 is an elevational View of the breaker, Fig. 14 is a sectional view along the lines XIV-XIV of Fig. 13, Fig. 15 is an exploded front view of portion of a pair of hammers forming part of the breaker, and Fig. 16 is an end view of the hammer.

Referring to the drawings and initially to Fig. 1 thereof, there is illustrated a typicaj glass manufacturing plant indicated generally by the reference numeral 1, having a conventional sand handling glass furnace 2 and a waste glass furnace 3 associated with a plate glass line 4 and a glass bottle line 5 feeding a glass recycling apparatus 8 through glass inlets 9 and then out a glass outlet 10 via a further glass crusher 6 to the waste glass furnace 3. Waste glass whether fully or partially produced is also fed from the furnaces 2 and 3 to the glass inlets 9. These are not shown to avoid unnecessarily confusing the drawings.

Referring to Figs. 2 to 6 inclusive portion of the glass recycling apparatus 8 is shown in more detail and comprises a trough indicated generally by the reference numeral 20 having a base floor 21 and an upper floor 22 spaced apart from the base floor 21. A cooling water inlet 25 and cooling water outlet 26 connected to a recycling pump (not shown) are also provided. Further an overflow outlet 27 is also provided as is a suitable sump drain 28. The base floor 21 of the trough 20 is upwardly inclined towards the outlet hopper 10. A conveyor, in this embodiment a modified drag chain conveyor, 30 is formed from a plurality of transversely arranged spaced apart scraper blades 31 mounted between chains 32 (see Fig. 5) and run from a tail drum 33 to a head drum 34 which head drum 34 is driven by a motor 35. To avoid unnecessary complications in the drawings and to avoid obscurity the drag chain conveyor 30 is not illustrated in detail in Figs. 2 to 4, but is simply illustrated by parts of the chain 32. Thus numerous portions of the chain 32 is omitted in each of these drawings that does not however detract from the understanding of the invention. It will be seen that the conveyor 30 moves over the upper floor 22 and then between the upper floor 22 and the base floor 21, essentially surrounding the upper floor 22. Ideally the upper floor 22 and the base floor 21 are covered with a suitable wear resistant material which is both abrasion and heat resistant. For example, abrasion and heat resistant tiles may be used.

Referring specifically to Fig. 6 there is illustrated the glass inlet 9 compirising a chute 40 housing a crusher indicated generally by the reference numeral 41 comprising a pair of contra-rotating rollers 42 driven by a motor 43. Mounted on the contra-rotating rollers 42 by pivot pins 45 are flail-like hammers 44.

In operafion, the conveyor 30 is driven in the direction of the arrow X across the upper floor 22 and in the direction of the arrow Y across the base floor 21 with the scraper blades 31 contacting the respective floors. The trough 20 is filled with water and the water is recirculated from the water inlet 25 through the trough 20 to the water outlet 26. The conveyor 30 is moved very slowly in the direction of the arrow X across the upper floor 22 and hot glass which will be delivered through the inlets 9, as is conventional, falls into the water where it will be shattered and will rest on the upper floor 22 where it will be scraped off it by the scraper blades 31 towards the end of the upper floor 22 where it will drop down onto the base floor 21 where it will then be delivered in the direction of the arrow Y, up the inclined portion of the base floor 21 to the outlet hopper 10. In the particular embodiment as described with reference to Fig. 6 the glass inlet 9 also mounts the crushers 41, 15. which will further break the glass prior to entry into the trough. The crushers 41 will be used when relatively large pieces are expected to need recycling.

By spacing the inlets 9 apart it is possible to avoid build up of glass, and also by bringing the glass back across the trough the length of the trough can be kept to a minimum.

Alternatively the waste glass itself can be used as a wear surface y leaving a space between the scrapper blades 31 and the floors 21 and 22 so that a layer of glass remains on the floor. The spacing would generally be of the order of 20 to 30 mm. While this is very efficient in that it reduces the wear on the floors, the problem is that there is then a higher power usage in moving the glass through the trough 20 as there is higher frictional resistance.

It is envisaged that the conveyor will move relatively slowly to ensure that there is sufficient dwell time in the trough to allow the glass to cool so that on delivery out the outlet it will not damage, for example, other conveyors such as rubber beft conveyors and the like could be used.

In addition it is envisaged that in many instances where the glass is very hot that it will shatter on coming into contact with the water and this helps the recycling, process. Needless to say all the glass will not be hot Referring now to Figs. 7 to 11 inclusive there is illustrated an alternative construction of glass crusher indicated generally by the reference numeral 50. The glass crusher comprises a hopper having a front wall 52, rear walls 53, side walls namely an upper side wall 54 and a lower side wall 55 mating along a parting line 56. The hopper has an open-mouthed inlet 57 and a discharge outlet 58. Secured by externally mounted bearings not shown on the lower side wall 55 is a shaft 60 carrying flail-like hammers 61. The flail--like hammers 61 are mounted between end plates 62 having a bore 63 for reception of the shaft 60 and four circumferentially spaced apart holes 64 carrying pivot bars 65. Similarly constructed intermediate plates 66 are mounted along the shaft 60 so that each flail-like hammer 61 is sandwiched between either two plates 66 or plates 62 and 66. Suitable spacers 67 are provided.

Portion of the front wall 52 and that portion of the upper sides walls 54 which are connected to the front wall 52 are pivotally mounted about a bearing 70. - Suitable releasable connectors, not shown, are provided to prevent pivoting except as required and to secure the hopper in a rigid condition for use.

Mounted within the hopper is a wear plate 75 pivotally mounted on a pivot bar 76.

A pusher arm 77 is pivotally mounted on the wear plate 76 at 78. The pusher arm 77 is movable into and out of the hopper by a control wheel 79 in conventional manner. Thus the wear plate 75 can be moved towards and away from the hammer like flails 61. A suitable motor 79(a) is provided with associated drive, not shown.

Preferably the interior of the glass crusher 50 is lined with suitable wear plates usually manufactured by wear resistant steel castings, In operation, referring to Fig. 7 glass is delivered through the inlet 57 and falls down between the wear plate 75 and the flail-like hammers 61 which are rotating in the direction of the arrow A. The rotating flail- like hammers 61 crush the glass which is then delivered out down beneath the shaft 60 and through the discharge outlet 58.

It can be seen from Fig. 8 how the upper side wall 54 which is attached to the front wall 52 can be pivoted downwards in the direction of the arrow B to allow the shaft 5 60 and flail-like hammers 61 to be exposed.

It will be noted that the parting line 56 has been chosen so as to allow any bearings carrying the shaft 60 to be securely mounted on the lower side wall 55 while at the same time sufficient of the upper side wall 54 can be pivoted out of the way to allow maintenance both on the bearings and shaft 60 but also on the flail-like hammers 61.

Referring to Figs, 12 to 17 there is provided a glass or more correctly a breaker indicated generally by the reference numeral 80 comprising a base support framework 82 on which is mounted an elongate hopper formed from a pair of side walls 83 and facing end walls 84. Projecting through the end walls 84 is a shaft 85 mounted between bearings 86. The shaft 85 is connected through a coupling 87 and gearbox 88 to an electric motor 89. Mounted within the hopper on the shaft 85 are a plurality of pairs of flail-like hammers 90 which are fast on the shaft 85. 20 Referring now to Fig. 15 each hammer 90 comprises a half cylinder 91 for engaging the shaft 85 and for connecting to half cylinder 91 to form a pair of hammers 90. The half cylinders 91 together combine to form a shaft protecting sleeve. It will be noted that each pair of hammers 90 are diametrically opposed 25 around the shaft 85 and for alternate hammers 90 along the shaft 65 they are each separated by 900. Round glass support bars 95 are mounted beneath the shaft 85 between the side walls 83 (see Fig.14). In use, elongate lengths of strips of glass which fall into the hopper will tall onto the 30 support bars 95 and will broken by the hammers 90.

While the crusher illustrated in Fig. 6 is ideally sited at the inlet to the glass recycling apparatus illustrated, there is no need for it to be sited there. in some instances it may be preferable to site glass crushers adjacent where the waste glass is actually produced a particular example of this would be where as wit other production processes glass is cut to size and there are large slivers or st(ips of glass produced during the production process. These can be extremely difficult to handle and thus a crusher such as illustrated in Figs 5 to 17 would be sited within the actual glass manufacturing plant and thus somewhat away from the rest of the glass recycling apparatus.

In other instances when the glass has been cooled and will itself in many instances have naturally shattered within the trough further crushing may take place to produce glass which is suitable for use in a waste glass furnace. Thus total flexibility of the positioning and use of the glass crushers as illustrated above are envisaged with the present invention.

In the specification the terms "comprise, comprises, comprised and comprising" or any variation thereof and the terms "include, includes, included and including" or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation and vice versa.

The invention is not limited to the embodiment hereinbefore described, but may be varied in both construction and detail within the scope of the claims.

Claims (19)

1 A glass recycling apparatus for waste glass produced at a number of stations in a glass manufacturing plant some of which glass may be hot comprising:

an elongate cooling water containing trough having a base floor and an upper floor spaced above and apart from the base floor within the trough; a glass inlet above the upper floor; a liquid passageway down through the trough from above to below the upper floor; a drag conveyor encompassing the upper floor and comprising an endless belt formed from a plurality of transversely arranged spaced apart scraper blades mounted on and projecting above and below endless flexible connectors the scraper blades being led across the upper floor and beneath ft across the lower floor in the opposite direction to a glass outlet, conveying means for delivering waste glass from the station to the glass inlet-, and glass crushers for the waste glass,

2. A glass recycling apparatus as claimed in claim 1 in which the scraper blades are spaced apart from the floors.

3. A glass recycling apparatus as claimed in claim 1 or 2 in which there is provided a plurality of waste glass inlets longitudinally arranged along the trough above the upper floor.

4. A glass recycling apparatus as claimed in any preceding claim in which the base floor of the trough inclines upwardly to the glass outlet.

5. A glass recycling apparatus as claimed in any preceding clairn in which there is provided a water recirculation pump for the trough.

6. A glass recycling apparatus as claimed in any preceding claim in which the glass crusher comprises a pair of contra rotating crusher rollers.

7. A glass recycling apparatus as claimed in claim 6 in which the contra rotating rollers carry outwardly projecting hammers.

B. A glass recycling apparatus as claimed in claim 7 in which the hammers are in the form of pivoially mounted flail-like hammers.

9. A glass recycling apparatus as claimed in any of claims I to 5 in which the glass crusher comprises a hopper having front rear and side walls, the side walls mounting a rotatable shaft carrying a plurality of axially spaced sets of circurnfrentially arranged flail-like hammers, the hopper having an open mouthed inlet and discharge outlet below the shaft in which portion of the front wall and portion of each of the two side walls connected thereto is pivotally mounted on the hopper.

10. A glass recycling apparatus as claimed in claim 9 in which the portions of the front and side walls define part of the hopper inlet and extend to adjacent the shaft.

11. A glass recycling apparatus as claimed in claim 9 or 10 in which the front wall carries a pivotally mounted wear plate opposite the hammers defining a passageway for glass therebetween and adjustment means for moving the wear plate towards and away from the shaft to vary the size of the passageway.

12. A glass recycling apparatus as claimed in any of claims 9 to I I in which the - is - shaft has fast thereon end and intermediate plates carrying a plurality of circumferentially arranged pivot bars each bar carrying in turn longitudinally arranged pivotally mounted hammers.

13.A glass recycling apparatus as claimed in any of claims 1 to 5 in which the glass crusher is in the form of a glass breaker comprising; an elongate hopper, having a pair of side walls and facing end walls; a shaft rotatably mounted betwe en the end walls; a plurality of radially arranged hammers mounted on the shaft; and a plurality of spaced apart glass support bars mounted between the side walls defining slots through which the hammers project on rotation of the shaft.

14. A glass recycling apparatus as claimed in claim 13 in which the hammers are mounted in pairs on the shaft and are diametrically spaced apart around the shaft.

15. A glass recycling apparatus as claimed in claim 13 or 14 in which the hammer in alternate pairs of hammers along the shaft are offset by 900 from each other.

16. A glass recycling apparatus as claimed in any of claims 13 to 15 in which each hammer is mounted on a half cylinder for connecting to another half cylinder to form a shaft protecting sleeve on a least one side of the hammer and in which the sleeve is mounted on each side of the hammer.

17. A glass recycling apparatus as claimed in any preceding claim in which the glass crusher is mounted adjacent the glass inlet to the trough.

is. A glass recycling apparatus as claimed in any preceding claim in which the glass crusher is mounted adjacent the glass outlet of the trough.

19. A glass recycling apparatus as claimed in any preceding claim substantially described herein with reference to and as illustrated in the accompanying 5 drawings.