IE87162B1 - A recirculating recycling system - Google Patents

Abstract

The present invention provides a recirculating recycling system which facilitates continuous processing of mixed waste materials for sorting prior to recycling, the recycling system comprising an input line operable to transport mixed material for sorting; two or more receptacles; one or more first sorting apparatus defining a first sorting phase and operable to direct items from the material on the input line into one of the two or more receptacles; an output conveyor; and at least one recirculating conveyor operable to direct material for further sorting; wherein the two or more receptacles are operable to selectively deposit material onto the output conveyor or the recirculating conveyor. <Figure 1>

Description

A Recirculating Recycling System Field of the invention This invention relates to a recirculating recycling system for use in the processing and sorting of waste, in particular large volumes of waste such as municipal waste or the like, and more particularly mixed dry waste products to be recycled, and which system provides a greater degree of separation of the various mixed materials while allowing the recycling process to be carried out continuously as opposed to the conventional batched processing of such materials.

Background of the invention Screening and sorting plants are typically used by waste management companies to sort mixed collected materials typically, paper, cardboard, plastic bottles, plastic films, steel and aluminium cans and the like. The plants can be of various size and capacity, depending on the local requirements and volumes of material that may need to be processed.

The screening and sorting plants conventionally consist of various mechanical screening machines interlinked by conveyor systems. In smaller scale facilities human operators can be used in place of machinery to pick the various recyclable items from a moving conveyor belt to be deposited into specific bunkers or other containers which are used to differentiate the products from the mixed materials.

In larger scale facilities mechanical machines are used to prepare the mixed materials into either defined size or shape prior to these products then being sorted by human operators to remove contaminants.

In current screening and sorting plants the design and process flow is linear, whereby the materials are typically only passed over the screening and sorting machine once, and then passed by the human operator(s) who also only have a single pass or opportunity to remove any contaminants from the material stream.

If there is an overloading of the screening and sorting system there is poor mechanical screening and sizing from the mechanical sorting machines and an increased level of contamination making it difficult for the human operators to reach the required level of contaminant removal.

If there is a high contamination rate in the screened material it is difficult to maintain a consistent output due in large part to human fatigue. There is also a health and safety risk in using human operators to screen products that have high contamination rates. 05/02/2019 It is therefore an object of the present invention to overcome the above mentioned problems of the prior art.

Summary of the invention According to the present invention there is provided a recirculating recycling system comprising an input line operable to transport mixed material for sorting; two or more receptacles; one or more first 10 sorting apparatus defining a first sorting phase and operable to direct items from the material on the input line into one of the two or more receptacles; an output conveyor; and at least one recirculating conveyor operable to direct material for further sorting; wherein the two or more receptacles are operable to selectively deposit material onto the output conveyor or the recirculating conveyor.

Preferably, the system comprises one or more second sorting apparatus defining a second sorting phase and operable to direct items into one of the two or more receptacles, the recirculating conveyor directing material to the one or more second sorting apparatus.

Preferably, the receptacles are arranged in two arrays with receptacles in the first array being 20 supplied with items from the first sorting apparatus, and receptacles in the second array being supplied with items from the second sorting apparatus.

Preferably, at least one of the second sorting apparatus is operable to direct items into one of the receptacles in the first array in order to facilitate recirculation of items back to the second sorting 25 phase.

Preferably, the receptacles in the second array are arranged to direct material onto the output conveyor.

Preferably, the system comprises at least one screening system upstream of the one or more sorting apparatus and operable to separate mixed material into two or more at least partially sorted material streams for supply to at least the first sorting apparatus.

Preferably, the at least one screening system comprises a first trommel.

Preferably, the at least one screening system additionally comprises a first ballistic separator supplied from a first outlet of the first trommel and supplying at least the first sorting apparatus.

Preferably, the at least one screening system additionally comprises a second ballistic separator 40 supplied from a second outlet of the first trommel and supplying at least the first sorting apparatus. 05/02/2019 Preferably, the at least one screening system additionally comprises a second trommel upstream of the first trommel, a first outlet of the second trommel supplying the first trommel.

Preferably, the system comprises a bag opening station fed from a second outlet of the second 5 trommel and which directs at least some of the contents of opened bags to one or more of the receptacles.

Preferably, the system comprises a quality control station through which the output conveyor passes.

Preferably, the system comprises one or more metal separating stations to which one or more streams of material may be fed from upstream and/or downstream of the one or more first sorting apparatus.

Preferably, the metal sorting station comprises a magnetic and/or eddy current separator.

Preferably, an output from the one or more metal separating stations is directed into one of the receptacles.

Preferably, the receptacles comprise a bidirectional discharge conveyor.

Preferably, the one or more first and/or second sorting apparatus each comprise an optical sorter.

As used herein, the term “upstream” is intended to refer to the relative position of a part or location of the recirculating recycling system with respect to the location or position of another part of the system, in particular with reference to the flow of material through the system, whereby the material will pass through an upstream part or location before passing through another part or location.

Brief description of the drawings The present invention will now be described with reference to the accompanying drawings, in which; Figure 1 illustrates a perspective view of a complete recycling plant incorporating a recirculating recycling system according to the present invention; Figure 2 illustrates an enlarged view of a recycling section of the recycling plant and housing the recirculating recycling system of the invention; Figure 3 illustrates a perspective view of the recycling section illustrated in Figure 2 but from the 40 opposite side thereof; 05/02/2019 Figure 4 illustrates the recycling plant of Figure 1 but from the reverse angle thereof; Figure 5 illustrates an array of receptacles forming part of the recirculated recycling system of the invention; Figure 6 illustrates a schematic end elevation of the recirculating recycling system; Figure 7 illustrates a schematic plan view of the recirculating recycling system of the invention; Figure 8 illustrates a schematic perspective view of the recirculating recycling system, from one angle; Figure 9 illustrates the schematic perspective view of the recirculating recycling system from another angle which is turned ninety degrees from that of Figure 8; Figure 10 illustrates a further schematic perspective view turned through ninety degrees from Figure 9; and Figure 11 illustrates a perspective view turned through ninety degrees from that of Figure 10. 20 Detailed description of the drawings Referring now to the accompanying drawings there is illustrated a recirculating recycling system, 25 generally indicated as 100, which in use will generally form part of a larger recycling plant 10 as illustrated in Figures 1-4. The recycling plant 10 comprises a front end 12 to which mixed materials to be recycled are delivered, a central recycling section 14 which is defined by the recirculating recycling system 100 of the invention, and a rear end 16 at which items exit in sorted streams for onward processing and/or storage, etc. The recirculating recycling system 100 of the present 30 invention differs from conventional recycling systems in allowing continuous processing of the materials to be recycled, as opposed to the conventional batched operation of existing systems and methods.

As with a conventional arrangement, the front end 12 comprises a tipping area 18 onto which 35 material to be sorted is deposited by any suitable conventional means, and an in feed trench 20 into which this material is loaded in conventional fashion. The material is transferred from the in feed trench 20 to a first trommel 22 of conventional design and operation, and which sorts the material into a first output which feeds the input of a second trommel 24, and a second output which feeds a bag opening station 26. The first and second trommels 22, 24 are arranged to sort the infeed 40 materials by splitting them into three fraction sizes, hereinafter referred to as oversized items which may consist of, for example, of unopened bags and very large cardboard pieces, which are fed to the 05/02/2019 bag opening station 26 from the first trommel 22, medium sized items from one output of the second trommel 24 and small sized items fed from a second output of the second trommel 24. This particular configuration is known in the art for sorting incoming streams of mixed materials into various grades for further processing. It is the arrangement of the recirculating recycling system 100 5 and its processing of the material from this point on that defines the present invention.

As described in greater detail hereinafter the recirculating recycling system 100 of the invention comprises an array of receptacles 28 defining containers into which individual materials or grades of a particular material are deposited, the system 100 additionally comprising an array of conveyors 10 and sorting apparatus operable to selectively deposit material from the mixed stream being fed from the trommels 22, 24 into sorted collections of material, for example oversized cardboard, cardboard, paper, plastic film, plastic bottles, aluminium items, steel items, glass, etc. Referring in particular to Figure 4 the recirculating recycling system 100 comprises an array of the receptacles 28 which in the embodiment illustrated are arranged into a pair of opposed rows each containing six of the receptacles 28, although it will be appreciated from the following description of the configuration and operation of the recirculating recycling system 100 that the number and particular arrangement and orientation of the receptacles 28 maybe varied as necessary.

In the embodiment illustrated each of the receptacles 28 comprises a base and tall side walls in 20 order to allow a substantial volume of material to be stored therein at any one time. In addition the base of each receptacle 28 is defined by a bidirectional conveyor which may therefore be selectively driven in either direction in order to expel material stored within the receptacle 28 from either open end thereof. In this way the material can be deposited onto one or other of a pair of conveyors running perpendicular the receptacles 28 as will be described in greater detail hereinafter. These 25 conveyors essentially comprise an output conveyor 30 which runs down the centre of the two rows of receptacles 28 and which is therefore common and accessible to both of the rows, allowing material in any of the receptacles 28 in either row to be deposited onto the output conveyor 30 to be transported to the rear end 16 of the recycling plant 10, again as will be described hereinafter in detail. An extended section 30a of the output conveyor 30 is also located on the other side of the 30 receptacles 28 of one of the rows, such that material can be deposited onto this extended section 30a of the output conveyor 30 which therefore effectively acts to define an overflow volume of the receptacles 28 in that row, allowing a greater capacity of material to be processed by the recirculating recycling system 100, and which is a factor is allowing the continuous operation of the recycling system 100. The receptacles 28 are additionally serviced by a recirculating conveyor 32 35 which runs perpendicular to the back of the receptacles 28 in the first row, and onto which material can be deposited from said receptacles 28 to be passed for further sorting as will be described in detail hereinafter.

The partially sorted streams and material exiting the second trommel 24 are passed as parallel 40 streams to a first ballistic separator 34 and a parallel second ballistic separator 36. The ballistic separators 34, 36 acts as a further screening step and separate three dimensional objects such as 05/02/2019 bottles, cans and the like from flatter two-dimensional material such as paper, cardboard and film. The ballistic separators 34, 36 preferably include screening decks which permit smaller pieces of paper, glass and other items to pass through and which are then transferred via a conveyor 38 or any other suitable means to a metal separating station comprising a magnetic separator 40 and an 5 eddy current separator 42 which are operable respectively to remove ferrous and aluminium items from the stream of material. The ferrous material separated may be deposited in a container such as a skip or the like (not shown). The aluminium material extracted by the eddy current separator 42 passes along a conveyor 44 and is deposited into one of the receptacles 28 to be outputted from the recycling section 14 once said receptacle 28 has been suitably filled. This is achieved by driving the 10 conveyor forming the base of the respective receptacle 28 in order to deposit the material onto the output conveyor 30/30a to be transferred to the rear end 16 of the recycling plant 10.

The remaining material in this particular stream is passed along a further conveyor 46 to an optical sorting apparatus in the form of an optical sorter 48 which operates in known fashion to identify 15 different materials and eject them in one direction or another using a blast of compressed air, such as to send a particular material into a particular receptacle 28. The optical sorter 48 incorporates a speed up conveyor at the entrance thereof which runs faster than the conveyor 46 feeding the optical sorted 48, and for example 1.5 times the speed thereof. This ensures that a single layer of material is presented to the scanning unit of the optical sorter 48, which consists of a near infrared scanning 20 unit operable in known fashion to determine the nature of the material passing therebeneath and which then triggers a blast of compressed air in order to eject the particular item in one direction or another from the optical sorted 48 to land in one or other of the adjacent receptacles 28. Again as each of these receptacles 28 fills with the particular material, whether paper, film, plastic bottles or the like, the contents thereof may be ejected onto either the output conveyor 30 running along the 25 centre of the two rows of the receptacles 28 to be transported to the rear end 16 of the recycling plant 10, or if further sorting or grading is required the contents of the particular receptacle 28 may be ejected in the opposite direction onto the recirculating conveyor 32 for further sorting as hereinafter described.

In similar fashion the parallel streams of material which leave the ballistic separators 34, 36 are passed to a pair of parallel optical sorters 50a, 50b, 50c which are again operable as hereinbefore described to draw the respective stream of material into a single layer of items for sorting into two of the receptacles 28 in the first row. Again from here the sorted material in the receptacles 28, when filled, may be ejected onto the output conveyor 30 or the recirculating conveyor 32, depending on the 35 direction the conveyor forming the base of receptacle 28 is driven. If the contents of the receptacle are sufficiently sorted and of a suitable quality they may be ejected onto the output conveyor 30; 30a, or alternatively where additional sorting is required onto the recirculating conveyor 32.

Where material from any of the receptacles 28 in the first row is ejected onto the recirculating 40 conveyor 32 it is transferred onto a transvers portion 50 of the recirculating conveyor 32 and to an additional optical sorter 52 which operates as hereinbefore described in order to separate the 05/02/2019 incoming material into two streams, a first which is deposited into one of the receptacles 28 in the second row, and a second stream which is passed onto a further optical sorter 54 which separates the materials into two outputs, one being deposited into the outermost receptacle 28 on the second row and a second stream which is deposited onto a conveyor 56 which deposits materials therefrom into the outermost receptacle 28 on the first row. In this way the material in this particular receptacle 28 can be ejected back onto the recirculating conveyor 32 to undergo a further pass of the optical sorters 52 and 54 should additional sorting being required. In this way a continuous recirculating loop is provided around which material can be continuously passed until the desired level of sorting and/or quality of materials is achieved.

It can also be seen that the output from the bag opening station 26 is fed via a conveyor 58 to be deposited into one of two of the receptacles 28 in the second row, which may fore example be used to store oversized cardboard items or the like.

Once the contents of any one of the receptacles 28 is of suitable quality and/or consistency of the particular material in question it is deposited onto the output conveyor 30; 30a which passes through a quality control station 60 in which one or more human operators are present in order to conduct a final visual inspection of the output from the recirculating recycling system 100, before said material is passed to the rear end 16 of the recycling plant 10. From here the material may enter a bailer 62 or any other suitable processing system to package the material for further use and/or processing depending on the material and/or quality thereof.

It will therefore be appreciated that the recirculating recycling system 100 of the present invention provides a means of permitting continuous processing of materials to be sorted for onward recycling, 25 and which can recirculate material any number of times in order to achieve a desired level of grading and/or quality of sorting.

Claims (17)

Claims

1. A recirculating recycling system comprising an input line operable to transport mixed material for sorting; two or more receptacles; one or more first sorting apparatus defining a 5 first sorting phase and operable to direct items from the material on the input line into one of the two or more receptacles; an output conveyor; and at least one recirculating conveyor operable to direct material for further sorting; wherein the two or more receptacles are operable to selectively deposit material onto the output conveyor or the recirculating conveyor.

2. A recirculating system according to claim 1 comprising one or more second sorting apparatus defining a second sorting phase and operable to direct items into one of the two or more receptacles, the recirculating conveyor directing material to the one or more second sorting apparatus.

3. A recirculating recycling system according to claim 2 in which the receptacles are arranged in two arrays with receptacles in the first array being supplied with items from the first sorting apparatus, and receptacles in the second array being supplied with items from the second sorting apparatus.

4. A recirculating recycling system according to claim 3 in which at least one of the second sorting apparatus is operable to direct items into one of the receptacles in the first array in order to facilitate recirculation of items back to the second sorting phase. 25

5. A recirculating recycling system according to claim 3 or 4 in which the receptacles in the second array are arranged to direct material onto the output conveyor.

6. A recirculating recycling system according to any preceding claim comprising at least one screening system upstream of the one or more sorting apparatus and operable to separate 30 mixed material into two or more at least partially sorted material streams for supply to at least the first sorting apparatus.

7. A recirculating recycling system according to claim 6 in which the at least one screening system comprises a first trommel.

8. A recirculating recycling system according to claim 7 in which the at least one screening system additionally comprises a first ballistic separator supplied from a first outlet of the first trommel and supplying at least the first sorting apparatus. 05/02/2019

9. A recirculating recycling system according to claim 8 in which the at least one screening system additionally comprises a second ballistic separator supplied from a second outlet of the first trommel and supplying at least the first sorting apparatus.

10. A recirculating recycling system according to claim 8 or 9 in which the at least one screening system additionally comprises a second trommel upstream of the first trommel, a first outlet of the second trommel supplying the first trommel.

11. A recirculating recycling system according to claim 10 comprising a bag opening station fed from a second outlet of the second trommel and which directs at least some of the contents of opened bags to one or more of the receptacles.

12. A recirculating recycling system according to any preceding claim comprising a quality control station through which the output conveyor passes.

13. A recirculating recycling system according to any preceding claim comprising one or more metal separating stations to which one or more streams of material may be fed from upstream and/or downstream of the one or more first sorting apparatus.

14. A recirculating recycling system according to claim 13 in which the metal sorting station comprises a magnetic and/or eddy current separator.

15. A recirculating recycling system according to claim 13 or 14 in which an output from the one or more metal separating stations is directed into one of the receptacles.

16. A recirculating recycling system according to any preceding claim wherein the receptacles comprise a bidirectional discharge conveyor.

17. A recirculating recycling system according to any preceding claim in which the one or more first and/or second sorting apparatus each comprise an optical sorter.