Support for photovoltaic modules for the treatment of said modules in a pyrolysis oven

Abstract

The invention relates to a support (500) for photovoltaic modules (100), intended to be inserted into a pyrolysis furnace, comprising: - a loading compartment (510), formed by a plurality of frames (511) providing spaces (512) between them, and allowing at least one photovoltaic module (100) to be held in each space (512), - a receptacle (520) comprising: * a tank having side walls (521), a bottom (522) and a main opening (523), the tank being intended to collect fragments of mineral matter from the photovoltaic modules after pyrolysis, the side walls being provided with secondary openings (524) to allow the circulation of gases present in the pyrolysis furnace, * support areas at the main opening to support the loading compartment (510) when it is positioned above the tank. Figure to be published with the abbreviation: Figure 3b

Description

Title of the invention: Support for photovoltaic modules for the treatment of said modules in a pyrolysis oven. FIELD OF THE INVENTION

[0001] The present invention relates to the field of photovoltaic module recycling. It relates in particular to a support for photovoltaic modules allowing the treatment of said modules in a pyrolysis furnace, for the thermal dismantling of the modules for the purpose of recycling the materials from which they are made. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] Given the exponential increase in photovoltaic panels produced and installed, their recycling becomes essential to recover and valorize the precious materials which compose them (metals, glass, silicon...) ([Fig.l]).

[0003] In a recycling process, the metal frame 110 (“frame”) of the end-of-life panels 200 and the junction box 150 are first separated from the photovoltaic module 100, which corresponds to the sandwich of functional layers, generally including a stack of glass 120, polymer layers 131, 132, 133 and photovoltaic cells 140 with semiconductor and metallic contacts.

[0004] It is then known to dismantle the photovoltaic module 100 either by a mechanical process or by thermal treatment based on a pyrolysis or combustion process. Tunnel furnaces (continuous processing, combustion process) or batch furnaces (batch processing, pyrolysis or combustion process) can be used. The polymer layers 131, 132, 133, included in the sandwich of functional layers (photovoltaic module 100), are formed of organic compounds, which are decomposed by pyrolysis or burned by combustion, thereby inducing the separation of the layers into mineral materials of the sandwich.

[0005] The efficiency of the thermal dismantling process necessarily depends on the design of the support used to support the photovoltaic modules 100 from the loading at the inlet of the furnace until the unloading at the end of the treatment. SUBJECT OF THE INVENTION

[0006] The present invention provides a support for photovoltaic modules adapted for processing said modules, particularly in a pyrolysis oven. The design of the support allows for excellent pyrolysis efficiency and very high-quality mineral material (from the modules) in fragments. BRIEF DESCRIPTION OF THE INVENTION

[0007] The invention relates to a support for photovoltaic modules, intended to be inserted into a pyrolysis oven, comprising:

[0008] - a loading compartment, formed by a plurality of frames providing between providing them with spaces, and allowing for at least one photovoltaic module to be maintained in each space.

[0009] - a receptacle comprising:

[0010] * a tank having side walls, a bottom and a main opening, the tank intended to collect fragments of mineral matter from photovoltaic modules after pyrolysis, the side walls being equipped with secondary openings to allow the circulation of gases present in the pyrolysis furnace,

[0011] * support areas at the main opening to support the loading compartment when positioned above the tank.

[0012] According to other advantageous and non-limiting features of the invention, taken alone or in any technically feasible combination: • the support areas are provided by horizontal bars connecting two opposite sides of the main opening or by a horizontal grid covering the main opening; • the tank has inclined internal walls which meet to form a gable roof, said internal walls having diffusers which put the inside and outside of the tank into fluidic communication; • the diffusers provide staggered openings to prevent fragments of mineral matter from passing outside the tank; • the gable roof rises at least halfway up the side walls; • the support is formed from a ferrous alloy or 304 stainless steel; • The receptacle has a hinged drain door, attached to a wall lateral to the tank and able to open when the tank is positioned on an inclined plane; • the receptacle has a hinged drain door, attached to the bottom of the tank and able to open when the tank is positioned above a container for recovering fragments of mineral materials; • the loading compartment is configured to hold the flat photovoltaic modules in a horizontal position, along a horizontal plane; • the charging compartment is configured to hold the flat photovoltaic modules in a vertical position, along a vertical plane; • the loading compartment has two longitudinal edges parallel to the vertical longitudinal plane, and it includes two guide panels, each arranged along a longitudinal edge, inclined outwards relative to the vertical longitudinal plane at an angle between 10° and 45°; • each guide panel has a height greater than or equal to one third of a vertical dimension of the photovoltaic modules when they are loaded in the charging compartment; • the loading compartment is removable and can be separated from the receptacle; • The support includes a cover configured to seal the main opening and secondary openings of the receptacle tank. BRIEF DESCRIPTION OF THE FIGURES

[0013] Other features and advantages of the invention will become apparent from the detailed description of the invention which follows with reference to the accompanying figures in which:

[0014] [Fig.1] Fig.1 presents an exploded view of a photovoltaic panel;

[0015] [Fig.2] Fig.2 shows fragments of mineral materials resulting from pyrolysis of photovoltaic modules, (A) according to a prior art process, (B) with a pyrolysis process using a support according to the present invention;

[0016] [Fig.3a] Figure [Fig.3a] shows a photograph of a support for photovoltaic modules according to a first embodiment of the invention;

[0017] [Fig. 3b] Figure 3b shows a cross-sectional view, along a plane (x,z), of a support for photovoltaic modules conforming to the first embodiment of the invention;

[0018] [Fig.4a] Figure [Fig.4a] shows a photograph of a support for photovoltaic modules according to a second embodiment of the invention;

[0019] [Fig. 4b] Figure 4b shows a cross-sectional view, along a plane (x,z), of a support for photovoltaic modules conforming to the second embodiment of the invention;

[0020] [Fig. 5] Figure 5 shows a side view, along a plane (y,z), of a receptacle of support for photovoltaic modules according to the invention;

[0021] [Fig. 6] Figure 6 shows a perspective view of a hooded support receptacle for photovoltaic modules according to the invention;

[0022] [Fig.7] Fig.7 presents a schematic view of a pyrolysis oven for batch processing, using a support for photovoltaic modules according to the invention.

[0023] Some figures are schematic representations which, for the purpose of readability, are not necessarily to scale or in which certain details are omitted. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention relates to a support 500 for photovoltaic modules 100, intended to enter an oven 1 in order to apply a pyrolysis treatment to said modules 100. This pyrolysis is implemented to dismantle the modules 100 with a view to recycling the mineral materials (glass, silicon, metals) which compose them.

[0025] The quality of the mineral materials recovered after pyrolysis is crucial for the profitability of a photovoltaic module recycling process. This quality depends on the complete degradation of the polymer layers into inorganic matter (gas + carbon residues) and the complete oxidation of the carbon residues into gas. Furthermore, the heat treatment time should be as short as possible for obvious economic reasons.

[0026] Loading a pallet of 100 photovoltaic modules, stacked one on top of the other, leads to very slow and poor-quality processing of the modules in the pyrolysis furnace. As an illustration, [Fig. 2] (A) shows a photograph of fragments of mineral materials resulting from pyrolysis in the aforementioned configuration: the glass fragments are relatively opaque due to the presence of brownish deposits (carbon residues); and pieces of carbon residue are present among the glass fragments, silicon, and aluminum wires. This complicates the sorting of the materials and affects the quality of their recycling.

[0027] Fig. 2 (B) shows a photo of fragments of mineral materials from a pyrolysis carried out using the support 500 for photovoltaic modules 100 according to the present invention: the fragments of glass, cells (silicon and silver contact) and aluminium are of good quality and no carbon residue is present.

[0028] To achieve such a result, the 500 support for 100 photovoltaic modules has been specifically optimized for: - to allow efficient and rapid heat transfer from enclosure 2 of pyrolysis oven 1 to the photovoltaic modules 100, ensuring good circulation of gas and / or air between said modules 100; - maintain an aerated architecture even after polymer decomposition to promote the kinetics of pyrolysis and then oxidation reactions; - to allow complete oxidation of carbon residues by providing air circulation at the end of the pyrolysis cycle; - improve the cooling speed, to minimize the duration of the treatment.

[0029] Because it is intended to be subjected to temperatures exceeding 500°C, the support 500 is formed from any material providing mechanical resistance at such temperatures. Preferably, it is made from a ferrous alloy, in particular from 304 stainless steel.

[0030] The support 500 according to the invention comprises a loading compartment 510, formed of a plurality of frames 511 providing spaces 512 between them, and allowing at least one photovoltaic module 100 to be held in each space 512 ([Fig.3a], [Fig.3b], [Fig.4a], [Fig.4b]). Each module 100 is thus held in a fully deployed state, i.e., flat, not folded upon itself.

[0031] By way of example, two or three modules 100 can be arranged in the same space 512; however, it remains advantageous for only one photovoltaic module 100 to be positioned in each space 512.

[0032] Typically, the spaces 512 have a width (interval between two frames 511, along the x-axis in Figures 3a and 3b, and along the z-axis in Figures 4a and 4b) of between 0.5 cm and 5 cm, for example 2 cm.

[0033] Typically, a 100 photovoltaic module is rectangular, its length is between 1 m and 2.5 m, its width is between 0.8 m and 1.5 m, and its thickness can vary between 2 mm and a few cm.

[0034] According to a first embodiment, illustrated in Figures 3a and 3b, each photovoltaic module 100 is positioned substantially vertically along a plane (y,z). The charging compartment 510 has two longitudinal edges parallel to the vertical longitudinal plane (y,z) and two lateral edges parallel to the vertical lateral plane (x,z). The longitudinal and lateral edges are not solid, but largely perforated. For example, as illustrated in [Fig. 3a], the longitudinal edges consist solely of metal bars 511a connecting the frames 511. Each frame 511 of the compartment 510 can be similarly stiffened by metal bars connecting two opposite sides of said frame 511.

[0035] The height of compartment 510 (along the z-axis in the figures) is preferably equal to or greater than the vertical dimension of modules 100 when loaded into spaces 512.

[0036] Advantageously, in this first embodiment, the loading compartment 510 comprises two guide panels 513, each arranged along a longitudinal edge. Each guide panel 513 is inclined outwards and upwards, forming an angle α between 10° and 45° with respect to the longitudinal vertical plane (y,z) ([Fig. 3a], [Fig. 3b]). These panels 513 allow the dislocated module pieces to be guided into the receptacle 520, which will be described later, and prevent some pieces from scattering in oven 1, in case of too sudden a dislocation or by rebound on the metal structure.

[0037] Advantageously, each guide panel 513 has a height greater than or equal to one third, or even half, of the vertical dimension of the photovoltaic modules 100 when they are loaded into the loading compartment 510 (in the example of [Fig.3a], the vertical dimension considered is the width of the modules 100).

[0038] According to a second embodiment, illustrated in Figures 4a and 4b, each photovoltaic module 100 is positioned substantially horizontally, along a plane (x,y). The charging compartment 510 has two longitudinal edges parallel to the vertical longitudinal plane (y,z) and two lateral edges parallel to the vertical lateral plane (x,z).

[0039] The structure of compartment 510 can be similar to that described in the first embodiment, except that it is tilted by 90° so as to provide horizontal support for the modules 100 instead of vertical support. In this second embodiment, the height of compartment 510 (along the z-axis) is defined by the number of frames 511 (and therefore loading spaces 512) provided.

[0040] Regardless of the embodiment, the loading compartment 510, with its ventilated structure, ensures separation between the photovoltaic modules 100 and excellent circulation of the gaseous atmosphere when the support 500 is within the pyrolysis oven 1.

[0041] The support 500 also includes a receptacle 520, to collect the pieces of the modules 100 when they break apart during the pyrolysis heat treatment.

[0042] This receptacle 520 comprises a tank having side walls 521, a bottom 522 and a main opening 523 ([Fig.3a], [Fig.3b], [Fig.4a], [Fig.4b], [Fig.5]). The tank is intended to collect fragments of mineral material from the photovoltaic modules 100 after dismantling by pyrolysis.

[0043] The receptacle 520 also includes support areas 523a at the main opening 523 to support the loading compartment 510 when it is arranged above the tank.

[0044] The support areas 523a can be provided by horizontal bars connecting two opposite sides of the main opening 523 ([Fig. 4a]) or by a horizontal grid 527 covering the main opening 523 (not shown). The mesh of the grid 527 is defined so that the pieces, resulting from the dislocation of the modules 100, and having a given lateral dimension, fall into the tank. The grid 527 may, for example, have holes with a diameter (or lateral dimensions) between 5 mm and 20 mm.

[0045] If it does not serve as support zones for the loading compartment 510, the horizontal grid 527 can alternatively be placed below the support zones 523a, at a given height in the tank ([Fig. 4b]). Note that another grid 528 can be implemented below the horizontal grid 527, lower in the receptacle tank 520. It preferably has smaller holes than the horizontal grid 527, typically on the order of 0.5 mm to 1 mm. These grids 527, 528 allow for sieving and promote efficient circulation of the gaseous atmosphere around the fragments by creating layers of fragments more likely to be in contact with the atmosphere than in the case of a single pile of fragments at the bottom of the tank.

[0046] The side walls 521 of the tank are advantageously provided with secondary openings 524 to allow the circulation of gases within the receptacle 520 during the pyrolysis heat treatment. The secondary openings 524 are typically located in the upper third of the walls 521.

[0047] Also advantageously, the receptacle 520 has inclined inner walls 525a, 525b that meet to form a gable roof 525 in the interior space of the receptacle ([Fig. 3b], [Fig. 4b]). The gable roof 525 preferably extends at least halfway up the side walls 521. The inner walls 525a, 525b have diffusers 5251 that establish fluidic communication between the interior of the receptacle and the exterior (ambient atmosphere or gaseous atmosphere within the furnace 1). Several diffusers 5251 can be arranged on each inner wall 525a, 525b to maximize the circulation of the gaseous atmosphere of the furnace 1 within the receptacle 520.

[0048] The diffusers 5251 preferentially provide baffled openings, to prevent the passage of fragments of dislocated modules 100 to the outside of the tank.

[0049] The receptacle 520 is advantageously equipped with a drain door 526. This door 526 is preferably hinged and can be either integral with a side wall 521 of the tank ([Fig. 5]) or integral with the bottom 522 of the tank (not shown). In the first case, external actuation of the door 526 allows it to be opened; alternatively, it can be configured to open when it is unlocked and the tank is positioned on an inclined plane, due to the pressure of the mineral fragments contained in the tank, which flow by gravity towards a recovery container. In the second case, unlocking the drain door, when the tank is positioned above the recovery container, leads to its opening and the fragments falling into the container.

[0050] In the support 500 according to the invention, it is advantageous that the loading compartment 510 be removable and can be separated from the receptacle 520. Indeed, following the pyrolysis heat treatment, the loading compartment 510 is empty and the step of recovering the fragments contained in receptacle 520 is made much more ergonomic by the removal of said compartment 510.

[0051] The fragments of mineral materials may have lateral dimensions on the order of centimeters, millimeters, or even smaller, which can then correspond to very fine particles capable of generating dust when the receptacle 520 is transported and during the unloading of the contents of the receptacle 520 into the recovery container. Thus, the support 500 may include a cover 530, configured to close the main opening 523 and the secondary openings 524 of the tank, in the absence of the loading compartment 510 ([Fig. 6]). The receptacle 520 thus covered can be stored or transported to a subsequent stage with a minor risk of particulate contamination of the plant. Furthermore, the dust raised by the flow of fragments during transfer to the recovery container is contained within the internal space of the tank.

[0052] The support 500 according to the present invention can, for example, be used in a pyrolysis oven 1 for batch processing, as illustrated in [Fig. 7]. The loading compartment 510, arranged on the receptacle 520, is first filled with photovoltaic modules 100 to be recycled, comprising (as mentioned in the introduction) a stack of glass 120, polymer layers 131, 132, 133, and photovoltaic cells 140 with semiconductor and metallic contacts. Each module 100 is positioned in a space 512 defined between two frames 511 of the loading compartment 510. The module 100 is kept flat; it is not folded over itself, which will greatly promote heat diffusion over its entire surface during the heat treatment.

[0053] Prior to their placement on the support 500, it is advantageous to break the glass layer 120 of the photovoltaic modules 100. Since this layer is made of tempered glass, it fractures into small, non-cutting pieces a few millimeters in size upon impact. Given the presence of the polymer layers 131, 132, 133, each module 100 nevertheless remains in its intact form, typically a rectangle of 1 to several square meters, and can be easily placed on the support 500. This pre-fracturing of the glass layer 120 allows for the recovery, at the end of the pyrolysis process (i.e., when all the polymer layers have been decomposed), of fragments of mineral materials (glass, semiconductors, metals), which are easier to sort and handle than large layers.

[0054] The support 500, including the loading compartment 510 holding the modules 100 and the receptacle 520, is introduced into the chamber 2 of the pyrolysis oven 1, via a sealed door 25. When the sealed door 25 is closed, the temperature inside the chamber 2 is increased, by means of heating means 41 (for example, one or more burners), to the pyrolysis temperature. This temperature is typically between 400°C and 600°C. Pyrolysis is carried out with little or No oxygen is present in the gaseous atmosphere of chamber 2 (typically less than 5% oxygen, or even less than 4%, or even less than 3%). The polymer decomposition kinetics are favored by the excellent gas circulation between the modules 100, which ensures rapid heat diffusion. A layered dislocation of module 100, linked to the decomposition of the polymer layers, occurs during pyrolysis. Since the glass layer 120 is previously broken, glass fragments fall onto the grid, the gable roof 525, and / or the bottom 522 of the tank, and the cell layer (silicon and contact) also breaks into pieces as a result of its fall.

[0055] The pyrolysis gases, resulting from the decomposition of the polymers, are burned in a post-combustion chamber 3, maintained at a temperature greater than or equal to 850°C (according to the standards imposed), by heating means 42,43 which may be burners, supplied with commercial combustion gas (natural gas, LPG) and an oxidant (for example air).

[0056] Once the polymers have decomposed and all (or a large majority) of the pyrolysis gases have been generated and burned in the afterburner chamber 3, an oxidation step at a temperature typically between 500°C and 800°C is carried out in the chamber 2 of the pyrolysis furnace 1, under an oxidizing atmosphere (for example, an oxygen content in the gaseous atmosphere of furnace 1 greater than or equal to 5%). This step eliminates carbonaceous residues and is all the more effective when the fragments of the dislocated modules are brought into contact with the oxidizing atmosphere.

[0057] The furnace temperature is then lowered (for example, in the range of 150°C to 300°C) to allow the support 500 to be removed. The empty loading compartment 510 is separated from the receptacle 520 containing the mineral material fragments and can be placed on another empty receptacle to be refilled with modules 100. The receptacle 520, the chamber of which is filled with fragments, is advantageously covered before being transported to the recovery container and emptied into it. Preferably, the horizontal grid 527 or other grid 528, if present, is also removed from the chamber before the receptacle 520 is covered.

[0058] The support 500 has been described above in a particular embodiment, but could be used in other types of pyrolysis furnaces, and according to different heat treatment sequences.

[0059] Of course, the invention is not limited to the embodiments and examples described, and alternative embodiments can be made without departing from the scope of the invention.

Claims

Demands

1. A support (500) for photovoltaic modules (100), intended to be inserted into a pyrolysis oven (1), comprising: - a loading compartment (510), formed of a plurality of frames (511) providing spaces (512) between them, and allowing at least one photovoltaic module (100) to be held in each space (512), - a receptacle (520) comprising: * a tank having side walls (521), a bottom (522) and a main opening (523), the tank being intended to collect fragments of mineral matter from the photovoltaic modules (100) after pyrolysis, the side walls (521) being provided with secondary openings (524) to allow the circulation of gases present in the pyrolysis oven (1), * support areas (523a) at the main opening (523) to support the loading compartment (510) when it is placed above the tank.

2. Support (500) for photovoltaic modules (100) according to the preceding claim, wherein the support areas (523a) are provided by horizontal bars connecting two opposite sides of the main opening (523) or by a horizontal grid covering the main opening (523).

3. Support (500) for photovoltaic modules (100) according to any one of the preceding claims, wherein the tank comprises inclined inner walls (525a, 525b) which meet to form a gable roof (525), said inner walls comprising diffusers (5251) putting the inside and outside of the tank into fluidic communication.

4. Support (500) for photovoltaic modules (100) according to the preceding claim, wherein the diffusers (5251) provide baffled openings, to prevent the passage of fragments of mineral matter to the outside of the tank.

5. Support (500) for photovoltaic modules (100) according to any one of claims 3 and 4, wherein the gable roof (525) rises at least halfway up the side walls (521).

6. Support (500) for photovoltaic modules (100) according to any one of the preceding claims, formed from a ferrous alloy or 304 stainless steel.

7. Support (500) for photovoltaic modules (100) according to any one of the preceding claims, wherein the receptacle (520) has a hinged drain door (526) attached to a side wall (521) of the tank and capable of opening when the tank is positioned on an inclined plane.

8. Support (500) for photovoltaic modules (100) according to any one of claims 1 to 6, wherein the receptacle (520) has a hinged drain door, integral with the bottom (522) of the tank and capable of opening when the tank is positioned over a container for recovering fragments of mineral matter.

9. Support (500) for photovoltaic modules (100) according to any one of the preceding claims, wherein the loading compartment (510) is configured to hold the flat photovoltaic modules (100) in a horizontal position, along a horizontal plane (x,y).

10. Support (500) for photovoltaic modules (100) according to any one of claims 1 to 8, wherein the loading compartment (510) is configured to hold the flat photovoltaic modules (100) in a vertical position, along a vertical plane (y,z).

11. Support (500) for photovoltaic modules (100) according to the preceding claim, wherein the loading compartment (510) has two longitudinal edges parallel to the vertical longitudinal plane (y,z), and it comprises two guide panels (513), each disposed along a longitudinal edge, inclined outwards with respect to the vertical longitudinal plane (y,z) at an angle between 10° and 45°.

12. Support (500) for photovoltaic modules (100) according to the preceding claim, wherein each guide panel (513) has a height greater than or equal to one third of a vertical dimension of the photovoltaic modules (100) when loaded into the loading compartment (510).

13. Support (500) for photovoltaic modules (100) according to any one of the preceding claims, wherein the charging compartment (510) is removable and can be separated from the receptacle (520).

14. Support (500) for photovoltaic modules (100) according to the preceding claim, comprising a hood (530) configured to close the main opening (523) and the secondary openings (524) of the receptacle tank (520).

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