Waste sorting facility

Abstract

Title: Waste sorting installation The invention relates to a waste sorting installation, in particular street sweepings, characterized in that it comprises a device (4) for screening the waste capable of separating at least three distinct fractions of the waste according to their size, the screening device (4) comprising: first screening means having meshes with a size of a value X1 capable of retaining a first fraction, called the coarse fraction, and of letting a second fraction, called the intermediate fraction, and a third fraction, called the fine fraction, pass through; second screening means having meshes with a size of a value X2, with X1 ≥ 4×X2, capable of retaining the intermediate fraction, and of letting the fine fraction pass through. Figure for the abstract: Fig. 1

Description

Title of the invention: Waste sorting installation Technical field

[0001] The field of the invention is that of the design of sorting installations.

[0002] The invention relates more particularly to a waste sorting installation, in particular road sweepings. State of the art

[0003] The various uses of roads produce an accumulation of "sediments" on the roads. These sediments are part of the by-products of sanitation; in fact, one of the aims of sweeping roads is to reduce the quantity of products entering the rainwater collection networks through the drains.

[0004] These products to be eliminated have several origins: - the degradation of roadways, - fragments of tires and mechanical parts, - animal droppings, - plant residues, - various waste left behind through negligence, etc.

[0005] They are collected by vacuum sweepers during routine maintenance, thus avoiding the accumulation of these more or less coarse fractions.

[0006] Sweepings are characterized by a mineral content of more than 60%, a high concentration of total hydrocarbons (TCH), and a high total organic carbon (TOC) content. In addition, these wastes are wet.

[0007] These characteristics (the percentage of mineral matter and the high humidity content) invalidate an incineration method for treating them.

[0008] Road sweepings are not permitted in inert waste storage facilities, as the HCT concentration and TOC content without prior treatment exceed the admissibility thresholds.

[0009] The majority of communities that attempted treatment via treatment plants did not continue their trials. The sweepings caused too much disruption to the general operation.

[0010] The majority of street sweepings are therefore sent to landfill, in storage facilities for non-inert, non-hazardous waste. At best, these facilities have gas recovery systems that allow energy production.

[0011] We also recall that in 2023, regional plans for waste management provide for a drastic reduction in the use of landfills and the law anti-waste and circular economy support in this direction. Technical problem

[0012] The invention aims in particular to overcome these drawbacks of the prior art.

[0013] More specifically, the invention aims to propose a solution for treating waste, including road sweepings, in a more virtuous manner than landfilling, and in a more optimal manner than treatment via treatment plants.

[0014] The invention also aims to provide such a solution which makes it possible to envisage recycling the collected waste. Summary of the invention

[0015] These objectives, as well as others which will appear subsequently, are achieved thanks to the invention which has as its subject a waste sorting installation, in particular street sweepings, characterized in that it comprises: - a waste screening device capable of separating at least three distinct fractions of the waste according to their size, the screening device comprising: • first sieving means having meshes with a size of a value XI capable of retaining a first fraction, called the coarse fraction, and of allowing a second fraction, called the intermediate fraction, and a third fraction, called the fine fraction, to pass; • second sieving means having meshes with a size of a value X2, with XI > 4xX2, capable of retaining the intermediate fraction, and allowing the fine fraction to pass; - a first storage area, placed under the screening device to collect the fine fraction; - an intermediate fraction conveyor at the outlet of the screening device, intended to collect the intermediate fraction; - a suction module associated with the intermediate fraction conveyor, to suck up waste with a weight less than a value X3; - a second storage area to collect waste sucked up by the suction module; - a third storage area at the exit of the intermediate fraction conveyor; - a coarse fraction conveyor at the outlet of the screening device, intended to collect the coarse fraction; - a fourth storage area at the exit of the coarse fraction conveyor.

[0016] Thanks to the installation according to the invention, it is possible to envisage a relatively significant recycling of sorted waste, and in particular street sweepings.

[0017] Indeed, for example for road sweepings, the first storage zone allows the fine fraction to be collected, which corresponds to very small particles that can be used in particular as backfill material, or for sanitation work. In the second storage zone, there is waste with a weight lower than the value X3, which corresponds for example to plastic compounds and various small waste such as cigarette butts, and in the third storage zone, there is a heavier fraction which corresponds in particular to mineral matter such as gravel. Finally, in the fourth storage zone, there are larger stones that can be reused in various sectors.

[0018] The sorting and targeting carried out then promotes reuse of the sorted waste.

[0019] According to a preferred characteristic, the value XI is equal to 50 mm, and in that the value X2 is equal to 8 mm.

[0020] Advantageously, the screening device takes the form of a double trommel.

[0021] Such a device makes it possible to carry out screening efficiently, that is to say quickly and precisely, while only occupying a limited space.

[0022] According to an advantageous characteristic, the screening device comprises a brush for unclogging at least one rotating screen of the double trommel.

[0023] Such a clogging brush is particularly advantageous in the case where the waste to be sorted is at least partially wet.

[0024] Advantageously, the unclogging brush is configured to brush the rotating screen having the smallest mesh, wet sand being able to tend to clog this type of screen.

[0025] According to an advantageous variant, the intermediate fraction conveyor comprises a feed chute provided at least partially with an anti-friction coating.

[0026] The anti-friction coating can be produced in particular by means of plates made of anti-friction material coupled to the structure of the feed chute.

[0027] This anti-friction coating makes it possible in particular to prevent particularly light particles, such as leaves, from becoming blocked at the feed chute, their weight and gravity then sometimes not being sufficient to allow them to flow properly into the hopper.

[0028] According to a preferred embodiment, the installation comprises a module for capturing ferromagnetic elements, the capture module integrating means for generating a magnetic field.

[0029] Sorting is thus carried out at the level of the coarse fraction in order to separate scrap metal elements, for example cans, of non-ferromagnetic mineral elements.

[0030] According to a preferred design, the installation comprises a terminal conveyor positioned at the outlet of the coarse fraction conveyor, the terminal conveyor comprising a conveyor belt with a relief provided with roughness, the conveyor belt extending longitudinally at an angle of between 20° and 40° with the horizontal, and the fourth storage area is subdivided into: - a first storage sub-zone located under a lower end of the slope of the conveyor belt, for waste having an essentially spherical shape and being likely to roll on the conveyor belt; - a second storage sub-area located under a high end of the conveyor belt slope.

[0031] This design makes it possible to differentiate particles of essentially spherical shape, these particles rolling on the conveyor belt and falling into the first storage sub-zone, from elements of non-spherical shape, which are carried by the conveyor belt and thrown into the second storage sub-zone.

[0032] According to an advantageous embodiment, the installation comprises a main feed hopper, and an initial conveyor feeding the screening device from the main feed hopper, the initial conveyor comprising a conveyor belt, and having a reinforced zone for receiving waste from the main feed hopper.

[0033] The reinforced receiving area makes it possible to avoid a rebound effect of the waste when it falls onto this area from the feed hopper.

[0034] According to a preferred characteristic, the initial conveyor comprises side cheeks bordering the conveyor belt, and seals located at the interface between the side cheeks and the conveyor belt.

[0035] This prevents very small particles from falling off the conveyor belt and disrupting the operation of the conveyor belt. Brief description of the drawings

[0036] Other characteristics and advantages of the invention will appear more clearly on reading the following description of different preferred embodiments of the invention, given as illustrative and non-limiting examples, and the single figure: • [Fig.l] [Fig.l] is a schematic representation of a sorting installation according to the invention. Detailed description

[0037] As can be seen in [Fig.l], a waste sorting installation is shown. This waste sorting installation is particularly suitable for sorting street sweepings.

[0038] This waste may include, but is not limited to, earth, sand, gravel, stones, scrap metal, plant waste such as leaves, plastic waste such as packaging waste.

[0039] The components of the installation described below are installed on a floor 1 which is preferably flat and horizontal. The components can be installed on the floor 1 either directly in the case where these components have a suitable base, or indirectly by means of a structure positioned on the floor 1 and on which the component is positioned. Such a height positioning of the components makes it possible in particular to provide storage areas into which the sorted waste can flow thanks to gravity, and to tilt the components relative to the horizontal if necessary.

[0040] The installation comprises a waste screening device 4, capable of separating at least three distinct fractions of the waste according to their size.

[0041] The screening device 4 comprises for this purpose first screening means and second screening means. These screening means take in particular the form of sieves, and more precisely cylindrical sieves. Indeed, according to the present embodiment, the screening device 4 takes the form of a double trommel. The two cylindrical sieves are then nested one inside the other, one cylindrical sieve having a smaller diameter than the other cylindrical sieve, and being located at least partially inside the other cylindrical sieve. These coaxial cylindrical sieves have an axis of rotation inclined relative to the horizontal so as to cause the waste to descend towards one of the sides of the sieves which is open to allow the retained waste to flow out. The waste to be sorted is fed from the inside of the smallest cylindrical sieve.

[0042] The screening device comprises motor means setting the screening means in motion. These motor means take the form in particular of an electric motor configured to drive the cylindrical screens in rotation and carry out the screening.

[0043] The first sieving means have meshes with a size of a value XI capable of retaining a first fraction, called the coarse fraction, and of allowing a second fraction, called the intermediate fraction, and a third fraction, called the fine fraction, to pass through.

[0044] By the expression "mesh with a size of a value", it is understood that the sieve has regular meshes defining square openings, with a spacing between the meshes equal to the given value, this measurement being taken from the center of a stitch in the center of the other directly adjacent stitch.

[0045] The screening device 4 comprises second screening means having meshes with a size of a value X2, capable of retaining the intermediate fraction, and of allowing the fine fraction to pass.

[0046] According to the present embodiment, the following ratio is respected: XI > 4xX2.

[0047] Preferably, the value XI is equal to 50 mm, and the value X2 is equal to 8 mm.

[0048] Concretely, the waste to be sorted is first sieved by the first means of sieving. The coarse fraction is then the only one retained by the sieve. Subsequently, the rest of the waste is sieved by the second sieving means, the sieve of which retains the intermediate fraction and lets the fine fraction pass through.

[0049] As can be seen in [Fig.l], the screening device 4 comprises a brush 41 for unclogging at least one rotating screen of the double trommel.

[0050] The unclogging brush 41 is notably configured to brush the exterior of the cylindrical screen of the second screening means which have the smallest mesh.

[0051] This unclogging brush 41 is driven in rotation by an electric motor. This unclogging brush in fact takes the form of a cylindrical brush formed by a multitude of strands extending axially around a mandrel.

[0052] The sorted waste is sorted again and / or distributed in storage areas as detailed below. The supply of waste to the screening device 4 is previously described below.

[0053] It is possible that the waste to be sorted is directly poured into the double trommel by a vehicle.

[0054] However, as illustrated by [Fig.l], and according to the present embodiment, the installation comprises: - a main feed hopper 2; - an initial conveyor 3 feeding the screening device 3 from the main feed hopper 2.

[0055] The main feed hopper 2 is configured to receive all of the waste to be sorted, and to gradually bring it onto the initial conveyor 3. This main feed hopper 2 has, for example, a capacity of 7m3.

[0056] The initial conveyor 3 comprises a conveyor belt. This conveyor belt is set in motion by means of an electric motor. The speed of the conveyor belt can be adjusted in order to optimize the sorting of waste.

[0057] The conveyor belt is a smooth belt, and is notably made of rubber.

[0058] The initial conveyor 3 has a reinforced zone for receiving waste from the main feed hopper 2.

[0059] This reinforced area is framed by panels delimiting a funnel. These panels allow waste to be guided towards the conveyor belt. These panels are, for example, formed by steel plates fixed to a frame of the initial conveyor 3.

[0060] In this reinforced receiving area, the conveyor belt is specially reinforced by means of additional support systems positioned under the conveyor belt. These support systems take the form of cylinders mounted to rotate around fixed axes.

[0061] In this way, waste landing on the conveyor belt in the reinforced area does not tend to bounce. If waste does bounce, or tends to come out due to the presence of other waste, the funnel-shaped panels allow it to be held on the conveyor belt.

[0062] The initial conveyor 3 also comprises lateral cheeks bordering at least partially the conveyor belt, and preferably bordering the conveyor belt over its entire length.

[0063] This prevents waste from falling to the side of the conveyor belt.

[0064] The initial conveyor 3 still includes seals located at the interface between the cheeks side and conveyor belt.

[0065] This prevents the fine fraction from escaping from the conveyor belt.

[0066] The initial conveyor 3 also comprises a V-shaped scraper at the base of the conveyor belt in order to avoid waste leakage at this level, and to avoid damage to the components of the initial conveyor 3 located nearby.

[0067] The installation comprises a first storage area 11. This first storage area 11 is placed under the screening device 4 to collect the fine fraction which has passed through the first screening means and the second screening means. This fine fraction thus falls into the first storage area 11 directly from the screening device 4 by the action of gravity.

[0068] The installation also comprises an intermediate fraction conveyor 5 at the outlet of the screening device 4. This intermediate fraction conveyor collects the intermediate fraction which has been retained by the second screening means and which emerges from the screening device. The intermediate fraction conveyor 5 thus collects the intermediate fraction.

[0069] This intermediate fraction conveyor 5 also comprises a conveyor belt.

[0070] The intermediate fraction conveyor 5 can also comprise: - panels, delimiting a feed chute, to guide the waste towards the conveyor belt; - side cheeks bordering at least partially the conveyor belt, and preferably bordering the conveyor belt along its entire length; - seals located at the interface between the side cheeks and the conveyor belt.

[0071] The feed chute is advantageously provided, at least partially, with an anti-friction coating. Preferably, it is entirely provided with an anti-friction coating on its internal faces. For example, the anti-friction coating may be formed by a plate or a film of anti-friction material.

[0072] According to the present embodiment, the installation further comprises a suction module 6 associated with the intermediate fraction conveyor 5, for sucking up waste with a weight less than a value X3.

[0073] This suction module 6 comprises a blower provided with a suction mouth positioned directly near the intermediate fraction conveyor 5, and more precisely, opposite a discharge end of the conveyor belt of the intermediate fraction conveyor 5, being oriented towards this discharge end.

[0074] The suction mouth is positioned at a distance of between 25 cm and 45 cm from the discharge end of the conveyor belt, depending on the humidity level of the incoming waste.

[0075] For example, the suction mouth can be positioned 20 centimeters from the discharge end of the conveyor belt.

[0076] This blower is configured so as to create a suction flow sufficient to suck up waste with a weight less than the value X3.

[0077] For example, this value X3 can be equal to 1 gram.

[0078] The blower also includes an outlet for expelling the sucked-up waste.

[0079] The installation comprises for this purpose a second storage zone 12 for collecting waste sucked up by the suction module 6. The expulsion mouth thus opens into this second storage zone 12.

[0080] The second storage area 12 may take the form of a box, advantageously closed, for example by being covered by a tarpaulin through which a pipe of the suction module is inserted to position the expulsion mouth in the box. This box may correspond to a skip having a lateral opening system in order to allow the skip to be carried and emptied simply and easily.

[0081] The installation also comprises a third storage zone 13 at the outlet of the intermediate fraction conveyor 5. This third storage zone 13 collects the part of the intermediate fraction which has not been sucked up by the suction module 6.

[0082] This third storage zone 13 is located in particular under the discharge end of the conveyor belt of the intermediate fraction conveyor 5.

[0083] The installation further comprises a coarse fraction conveyor 7 at the outlet of the screening device 4, and which is intended to collect the coarse fraction.

[0084] As is apparent from the preceding description, the coarse fraction conveyor 7 collects the coarse fraction which was retained by the first sieving means.

[0085] The coarse fraction conveyor 7 comprises a conveyor belt, preferably smooth, and may also comprise: - panels delimiting a funnel to guide the waste from the coarse fraction towards the conveyor belt; - side cheeks bordering at least partially the conveyor belt, and preferably bordering the conveyor belt along its entire length.

[0086] The installation comprises a fourth storage zone 14 at the outlet of the coarse fraction conveyor (7).

[0087] According to one possible embodiment, the fourth storage zone 14 collects the entire coarse fraction in an undifferentiated manner.

[0088] According to the present embodiment, the fourth storage area 14 is subdivided into a plurality of sub-areas to enable sorting of the coarse fraction to be carried out.

[0089] Indeed, the fourth storage zone 14 is subdivided into a first storage sub-zone 141, a second storage sub-zone 142, a third storage sub-zone 143.

[0090] The first storage sub-zone 141 is intended to receive waste from the coarse fraction which assumes an essentially spherical shape and which is capable of rolling on an inclined surface.

[0091] The second storage sub-zone 142 is intended to receive the waste from the coarse fraction which is not likely to roll on an inclined surface.

[0092] Finally, the third storage sub-zone 143 is intended to receive waste from the coarse fraction which is metallic, and more precisely ferromagnetic.

[0093] The installation, according to the present embodiment, comprises: - a terminal conveyor 9 positioned at the exit of the coarse fraction conveyor 7; - a module for capturing 8 ferromagnetic elements.

[0094] The ferromagnetic element capture module 8 is more precisely associated with the coarse fraction conveyor 7 in order to capture the ferromagnetic elements contained in the coarse fraction.

[0095] The capture module 8 is located at the level of a chute for ejecting the coarse fraction from the coarse fraction conveyor 7.

[0096] The ejection chute is located partly in line with the end of the conveyor belt of the coarse fraction conveyor 7 through which the coarse fraction is ejected. In this way, the coarse fraction falls by gravity into the ejection chute.

[0097] The capture module 8 comprises a slide 81 extending downwards from the ejection chute towards the third storage sub-area 143.

[0098] The upper end of the chute 81 is not located directly above the end of the conveyor belt of the coarse fraction conveyor 7 by which the coarse fraction is ejected into the ejection chute. Nevertheless, the capture module 8 comprises means for generating a magnetic field capable of magnetically capturing the ferromagnetic elements of the coarse fraction which fall into the ejection chute to redirect them towards the chute 81. In this way, the ferromagnetic waste of the coarse fraction is redirected towards the third storage sub-zone 143.

[0099] The coarse fraction waste which is not ferromagnetic and which passes through the ejection chute undergoes further sorting.

[0100] Indeed, the installation comprises a terminal conveyor 9 comprising a conveyor belt with a relief provided with roughness. This conveyor belt extends longitudinally forming an angle of between 20° and 40° with the horizontal, that is to say with the ground 1.

[0101] This conveyor belt is configured to advance from the bottom of the slope to the top of the slope.

[0102] The second storage sub-area 142 is located under a high end of the slope of the conveyor belt, while the first storage sub-area 141 is located under a low end of the slope of the conveyor belt.

[0103] In this way, the coarse fraction waste which assumes an essentially spherical shape, and which is capable of rolling on an inclined surface, rolls on the conveyor belt in the opposite direction to the direction in which the conveyor belt is going, and falls into the first storage sub-area 141.

[0104] The waste from the coarse fraction which is not likely to roll on an inclined surface is conveyed by the conveyor belt to the top of the slope from where it falls into the second storage sub-zone 142.

[0105] The installation finally includes means for supplying electricity to all of the installation's electrical systems, in particular the electric motors of the conveyors, the double trommel, and the blower, and for controlling these electrical systems.

[0106] Following the sorting of road sweepings, the following may be found, for example: - sand in the first storage area 11; - packaging waste, masks, cigarette butts, and leaves in the second storage area 12; - gravel in the third storage area 13; - spherical waste such as round stones in the first sub-zone storage 141 of the fourth storage area 14; - non-spherical waste in the second storage sub-zone 142 of the fourth storage zone 14; - scrap metal in the third storage sub-area 143 of the fourth storage area 14.

[0107] The sorting installation provides a solution for treating waste in a more virtuous way than landfilling, and in a more optimal way than treatment via treatment plants.

Claims

Claims

1. Waste sorting installation, in particular street sweepings, characterized in that it comprises: - a waste screening device (4) capable of separating at least three distinct fractions of the waste according to their size, the screening device (4) comprising: • first sieving means having meshes with a size of a value XI capable of retaining a first fraction, called the coarse fraction, and of allowing a second fraction, called the intermediate fraction, and a third fraction, called the fine fraction, to pass; • second sieving means having meshes with a size of a value X2, with XI > 4xX2, capable of retaining the intermediate fraction, and allowing the fine fraction to pass; - a first storage area (11), placed under the screening device (4) to collect the fine fraction; - an intermediate fraction conveyor (5) at the outlet of the screening device (4), intended to collect the intermediate fraction; - a suction module (6) associated with the intermediate fraction conveyor (5), for sucking up waste with a weight less than a value X3; - a second storage area (12) for collecting waste sucked up by the suction module (6); - a third storage zone (13) at the outlet of the intermediate fraction conveyor (5); - a coarse fraction conveyor (7) at the outlet of the screening device (4), intended to collect the coarse fraction; - a fourth storage zone (14) at the outlet of the coarse fraction conveyor (7).

2.

3. Installation according to the preceding claim, characterized in that the value XI is equal to 50 mm, and in that the value X2 is equal to 8 mm. Installation according to any one of the preceding claims, ca- characterized in that the screening device (4) takes the form of a double trommel.

4. Installation according to the preceding claim, characterized in that the screening device (4) comprises a cleaning brush (41) of at least one rotating screen of the double trommel.

5. Installation according to any one of the preceding claims, characterized in that the intermediate fraction conveyor (5) comprises a feed chute provided at least partially with an anti-friction coating.

6. Installation according to any one of the preceding claims, characterized in that it comprises a capture module (8) for ferromagnetic elements, the capture module (8) integrating means for generating a magnetic field.

7. Installation according to any one of the preceding claims, characterized in that it comprises a terminal conveyor (9) positioned at the outlet of the coarse fraction conveyor (7), the terminal conveyor (9) comprising a conveyor belt with a relief provided with roughness, the conveyor belt extending longitudinally at an angle of between 20° and 40° with the horizontal, and in that the fourth storage zone is subdivided into at least: - a first storage sub-zone located under a lower end of the slope of the conveyor belt, for waste assuming an essentially spherical shape and being capable of rolling on the conveyor belt; - a second storage sub-zone located under a high end of the slope of the conveyor belt.

8. Installation according to any one of the preceding claims, characterized in that it comprises a main feed hopper (2), and an initial conveyor (3) feeding the screening device (3) from the main feed hopper (2), the initial conveyor (3) comprising a conveyor belt, and having a reinforced zone for receiving waste from the main feed hopper.

9. Installation according to the preceding claim, characterized in that the initial conveyor (3) comprises lateral cheeks at least partially bordering the conveyor belt, and seals located at the interface between the side cheeks and the conveyor belt.

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