WO2006030172A2

WO2006030172A2 - Improved bag splitter device

Info

Publication number: WO2006030172A2
Application number: PCT/GB2005/003321
Authority: WO
Inventors: Gordon Moorehead; David Owen
Original assignee: WASTEC Ltd
Current assignee: WASTEC Ltd
Priority date: 2004-09-13
Filing date: 2005-08-24
Publication date: 2006-03-23
Anticipated expiration: 2007-03-13
Also published as: WO2006030172A3; GB2417914A; GB2417914B; GB0420338D0

Abstract

The present invention provides a bag splitter device, for use in a waste management apparatus, comprising a hopper for receiving mixed waste material, said hopper containing: a lower end region being provided with a unit for tearing open any of said received waste material that is held in bags, and a first exit for receiving waste so torn open from said bags; and (ii) an upper end region being provided with one or more resilient tines, and a second exit for disposing of non-tearable items of waste.

Description

Improved Bag Splitter Device

The present invention relates to a device for use in a waste separation apparatus, particularly an improved bag splitter device that can be used in such an apparatus for separating domestic waste material.

Such material is normally in a co-mingled state and can consist of newspapers, cardboard, plastic bottles, glass, organic waste and other such items. With increasing environmental awareness, objections have grown to the use of landfill and incineration for disposing of domestic waste. Recycling has therefore come to be seen as an environmentally friendly way of dealing with waste. In order for recycling to be possible, the waste must be separated material by material. Hence paper, steel, aluminium, glass, textiles, plastics, organic waste and other components of waste must all be separated one from another.

Accordingly, the sorting of waste material for recycling has become a major problem. Many different systems have been developed in order to extract various components of waste. Certain elements of waste are more readily removed than others. For example magnetic or eddy current separators may be used for metallic waste, such as beverage cans. Meshes and filters may be used to remove and separate fine waste materials. Air blowers may be used to remove paper and plastic sheet. Inevitably the processes are not entirely material specific. For example non-metallic debris may be picked up with the beverage cans during eddy removal. Paper and plastics may remain mixed after air blowing and glass and textiles may be difficult to separate by means other than hand picking. The difficulties of separating domestic waste into recyclable separated quanta has led to the development of alternative waste management systems in which waste is separated by the domestic household. Local bottle and paper banks have been created where residents may deposit their glass and paper waste into discrete banks. In the home waste collection agencies may provide different coloured waste bags. These are then assigned for use for paper, organic, plastics, glass or other waste. The success of these methods relies upon the co¬ operation of the householders. Because of the extra work that separation of waste requires within the household even the best intentioned of families find the process an inconvenient chore. Hence unless legal instruments are used to enforce waste separation within the home, there is little hope for its efficacy as a separation method.

Hence efforts have continued in the development of methods for separating co- mingled domestic waste away from the household. It is possible to separate certain elements of waste by, for example, relying upon the different physical properties of or dimensions of waste material. There is a requirement for a separation system, which can reasonably efficiently separate waste material into recyclable portions, with a minimum of un-recyclable end product.

The present applicant's co-pending patent application WO 2004/012866 discloses a waste separation system for separating domestic waste comprising: means for introducing co-mingled domestic waste held in discrete bags onto a loading waste conveyor; a bag splitter into which the waste bags are conveyed and which directs a stream of liberated waste onto; a kinetic separator comprising a generally horizontally reciprocating table which separates waste on the basis of variations in travelling response to a snatch action imparted to the table by the reciprocation, the table being formed with sloping portions which direct waste on the one hand to one or both side regions of the table and on the other hand to a distal end region of the table, a secondary waste exit means at a distal end of the table providing an exit for waste which travels the length of the table; primary waste exit means at one or both side regions of the table for waste which is directed to a side region of the table by virtue of the reciprocating motion thereof; a primary waste conveying means for transporting waste from the primary exit means of the table; a screen separator into which is conveyed primary waste, which separator comprises one or more vibrating screens for removing relatively fine debris from the primary waste, and conveying the remaining waste; an air drum separator which receive an air drum separator which receives the remaining waste, which air drum separator is adapted to entrain articles of paper or sheet plastics; a picking station along which is conveyed un-entrained waste from the air drum separator, which picking station permits removal of glass and textiles from the waste stream; a magnetic separator which removes magnetic metallic material from the waste stream by magnetic attraction; an eddy current separator for separating plastic articles, magnetic metallic articles and non-magnetic metallic articles one from another.

The bag splitter mentioned above works on the principle of containing the waste until the bags of waste are thoroughly opened.

To put this approach into effect, the prior bag splitter consists of a number of rotating drams with attached pointed protrusions. The drums are contained within a box, or hopper, with solid walls, the two solid end walls being fitted with protrusions to prevent unopened bags from being squeezed through the device unopened. Such technology was adequate whilst waste was collected in bin bags, however the introduction of large wheeled bins has allowed householders to include larger, bulkier items in their waste, which cannot pass between the drums of existing bag splitters.

Thus, one aim of the present invention is to provide a solution to the disadvantages of the prior bag splitter devices, so that in particular waste containing larger, bulkier items can still be processed.

According to one aspect of the present invention, a bag splitter device, for use in a waste management apparatus, comprising a hopper for receiving mixed waste material, said hopper containing:

(i) a lower end region being provided with a unit for tearing any items of said received waste material that are tearable, and a first exit for receiving waste so torn; and

(ii) an upper end region being provided with one or more resiliently mounted obstructing members, and a second exit for disposing of non-tearable items of waste.

Typically, the tearing unit comprises a plurality of rotatably driven spindles, each spindle provided with a plurality of coaxially disposed spaced apart tearing members, each tearing member optionally comprising several radially extending arms.

Preferably, all said spindles rotate in the same direction, optionally being in a direction towards the second exit.

In a preferred embodiment, the arrangement of said obstructing members and the rotation of the tearing members is such as to direct said non-tearable items of waste laterally through the upper end region and its obstructing members so as to exit laterally through the second exit; and to direct said waste material held in bags perpendicularly downwards, relative to the lateral movement of said non-tearable items, into the unit for tearing in the lower end region such that said waste material held in bags is torn open from said bags and disposed of downwards through said first exit.

Preferably, the relative resilience of said resiliently mounted obstructing members is such as to resist lateral momentum of incoming bags of waste moved at least by said unit for tearing, so as to direct said bags downwards into the lower end region of the hopper; and is such as to allow lateral movement of said non-tearable items out of the second exit and away from the lower region of the hopper.

Typically, each obstructing member comprises one or more tine(s). Usually, the resilient mounting of each obstructing member is hydraulically operated.

Typically, the non-tearable items are items that are larger, more rigid and/or bulkier that said tearable items; optionally, the tearable items includes waste material held in non-rigid bags.

The tearing members preferably have a star configuration, for example six pointed stars. The purpose of the "bag splitter" is to liberate the contents of the as received source material prior to presentation to, for example, a kinetic streaming equipment, but without presenting larger and bulkier items to such a kinetic streaming equipment.

The bag splitter can exist as a stand-alone unit of a particular size or can be used in parallel with similar units to suit a given plant's requirements. A unit can be fed in a controlled manner in a number of ways such as by grab crane, belt feed, or screw conveyor.

In one embodiment, the bag splitter may consist of rows of parallel rotating shafts each containing a number of "star-wheels" over their length. The shafts, wheels, and distance between the rows can be set at pre-determined distances from one another depending upon the particular application. The speed and direction of rotation of these shafts may be variable one with respect to another in order to modify and enhance the release effect.

Material in bags is directed by the resilient tines so as to enter the lower end region of the device's hopper from above and falls onto the sole or upper row of star- wheels. These wheels then force apart compacted items within the waste and tear open any bags or containers releasing their contents. Released material is then free to fall through gaps between individual wheels and onto any next row. If a plurality of rows is present, they may be arranged one above another, and each row of wheels may have a reduced fall-through gap, thus gradually reducing the average product size into a suitable size for streaming purposes.

Upon exit from the splitter, the material that was in the bags can be either directly loaded onto a single kinetic streamer or fed to numerous streamers at pre-determined constant feed rates by means of screw conveyors, or other conveyors.

Meanwhile, the bulkier items exit the splitter separately and in a relatively lateral direction (parallel to the motion of the rotating tearing members) of the tearing unit, so as to be disposed of in a more appropriate way.

Further optionally, preferred features are evident from the accompanying subsidiary claims.

The following is a non-limiting description, by way of example only, of an embodiment of the present invention with reference to the accompanying drawings, in which:

Figure 1 shows a side view of a bag splitter according to one embodiment of the present invention;

Figure 2 shows an end view of the device shown in Figure 1;

Figure 3 illustrates a plan view of the device shown in Figures 1 and 2;

Figure 4 depicts a tine, being a component of the device as shown in Figures 1 to 3;

Figure 5 shows a star-wheel half, being part of a component of the device as shown in Figures 1 to 3;

The bag splitter 10 shown in Figure 1 is also shown in Figures 2 to 3. The splitter comprises a hopper 100. The hopper is located over a base 101 that carries a row of spindles 102 within a lower end region 105 of the hopper. The spindles 102 each carry a plurality of six-pointed star shaped tearing wheels 104, each held on a wheel drum 105. The row comprises four horizontally spaced parallel spindles 102. Each spindle carries a plurality of six-pointed star shaped tearing wheels 104. If desired, further rows of spindles 102 may be provided, such that the rows can be located one above the other.

Within an upper end region 107 of the hopper are held three rows of tines 108, each row of tines being associated with a respective one of the spindles 102. Each tine acts in a resilient manner due to an associated hydraulic operating mechanism 109.

Figure 4 shows an individual tine 108 and its attachment point 115 for its associated hydraulic operating mechanism.

Figure 5 shows a half section of one of the star shaped tearing wheels as used in this embodiment.

Each spindle is driven by a unique variable speed bi-directional electric motor 107. The motors are provided with a controller (not shown) allowing user adjustment of spindle rotation speed and direction. Differential directions and speeds as between adjacent spindles can provide enhanced shearing and tearing action.

The hopper 100 is three-sided, being open at one end (that is, at the second exit of the upper end region of the hopper). Waste materials are loaded 112 by chute 111 at the feed end of the device, which is opposite the open end. The drums 106 rotate in the same direction towards the open end of the hopper, the speed of rotation being variable and different for each drum 106. The direction of rotation is also reversible.

The purpose of the resiliently mounted tines 108 is to hold back bags of waste to allow the star wheels to tear them open, such that liberated materials can pass between the star wheels and fall onto a conveyor (not shown). However, larger items such as carpets, ironing boards, duvets, wood, cardboard boxes, and so forth, that are too large to fall between the drum's star wheels are sufficiently rigid to displace the tines 108, so as to be advanced by the star wheels towards the open end, passing under the displaced tines 108 and through the open end to exit the hopper.

Thus, the present invention provides a new, improved bag splitter that has the advantage of being able to separate large items present in incoming waste material out of its hopper for disposal elsewhere, whilst other less bulky material can be processed ready for conveyance onwards through a different exit.

Claims

CLAIMS:

1. A bag splitter device, for use in a waste management apparatus, comprising a hopper for receiving mixed waste material, said hopper containing:

(iii) an upper end region being provided with one or more resiliently mounted obstructing members, and a second exit for disposing of non-tearable items of waste.

2. A device as claimed in claim 1, wherein the tearing unit comprises a plurality of rotatably driven spindles, each spindle provided with a plurality of coaxially disposed spaced apart tearing members, each tearing member optionally comprising several radially extending arms.

3. A device as claimed in claim 2, wherein all said spindles rotate in the same direction, optionally being in a direction towards the second exit.

4. A device as claimed in either claim 2 or claim 3, wherein the arrangement of said obstructing members and the rotation of the tearing members directs said non-tearable items of waste laterally through the upper end region and its obstructing members so as to exit laterally through the second exit; and directs said waste material held in bags perpendicularly downwards, relative to the lateral movement of said non-tearable items, into the unit for tearing in the lower end region such that said waste material held in bags is torn open from said bags and disposed of downwards through said first exit.

5. A device as claimed in any preceding claim, wherein the relative resilience of said resiliency mounted obstructing members is such as to resist lateral momentum of incoming bags of waste moved at least by said unit for tearing, so as to direct said bags downwards into the lower end region of the hopper; and is such as to allow lateral movement of said non-tearable items out of the second exit and away from the lower region of the hopper.

6. A device as claimed in any preceding claim, wherein each obstructing member comprises one or more tine(s).

7. A device as claimed in claim 6, wherein the resilient mounting of each obstructing member is hydraulically operated.

8. A device as claimed in any preceding claim, wherein the non-tearable items are items that are larger, more rigid and/or bulkier that said tearable items; optionally, wherein the tearable items include waste material held in non-rigid bags.

9. A device as claimed in any one of claims 2-8, wherein the tearing members have a star configuration, for example six pointed stars.

10. A device as claimed in any one of claims 2-9, wherein the tearing members on adjacent spindles overlap so that space between tearing members on one spindle is occupied by the radially extending arms of a tearing member on the adjacent spindle.

11. A device as claimed in any of claims 2-10, wherein the spindles are arranged in one or more horizontally extending rows.

12. A device as claimed in claim 11, wherein the spindles are arranged in two or more horizontally extending rows, one row above the other.

13. A device as claimed in claim 12 wherein each relatively uppermost row is arranged so that free space between spindles and tearing members of each relatively uppermost row is greater than free space between the spindles and tearing members of each relatively lowermost row, so that larger size particles may pass through the upper rows than the lower rows.

14. A device as claimed in claim 13, wherein the free space is achieved by providing a greater density of tearing members per spindle on the spindles of the lower rows.

15. A device as claimed in any of claims 2-14, wherein each spindle is provided with drive means that allow for different rotational speeds or rotational directions as between spindles within a row, and/or as between spindles in different rows.

16. A device as claimed in any of claims 6-15, wherein each spindle is associated with a row of tines extending horizontally in a direction perpendicular to the direction in which the rows of spindles extend.

17. A device as claimed in claim 16 wherein, a portion of each tine is located between successive tearing members.

18. A device substantially as hereinbefore described with reference to, and/or as illustrated by, the accompanying drawings.