Installation for the transformation of an expanded polymer into magma

Abstract

The invention relates to an installation for transforming a polymer, particularly expanded polystyrene, using a reagent, from an expanded solid state to an unexpanded amorphous state to obtain a magma of a pasty and flexible consistency. The installation comprises: a receiving chamber for receiving the polymer to be transformed; a grinding device for grinding the polymer; a treatment chamber comprising a spraying device for spraying the reagent onto the ground polymer to obtain a magma; a separation chamber comprising a dewatering device for dewatering the magma to extract a liquid containing the reagent, thus obtaining a dewatered magma; a first discharge device for removing the dewatered magma from the separation chamber; and a second discharge device for removing the extracted liquid from the separation chamber. Figure 1 (for the abstract)

Description

Title of the invention: Installation for the transformation of an expanded polymer into magma. Technical field

[0001] The invention relates to the field of recycling and recovery of polymers, and more particularly to the transformation of a polymer, such as an expanded polymer like expanded polystyrene.

[0002] The invention relates more specifically to an installation for transforming such a polymer from an expanded solid state to an unexpanded amorphous state to obtain a magma. Previous technique

[0003] The use of expanded polystyrene-type polymers is very widespread, particularly in the field of packaging for shock protection. Traditionally, expanded polystyrene blocks are used in the packaging of household appliances or computer equipment.

[0004] One disadvantage of expanded polystyrene is that it generates large quantities of waste, which are difficult to recycle.

[0005] Document WO99 / 07776 describes a solution to this problem, consisting of a process for transforming an expanded polymer into a pasty and flexible magma. By magma, we mean a substance having a viscous and malleable texture, capable of deforming or flowing slowly under the influence of external forces, such as gravity, while retaining a certain cohesion and plasticity.

[0006] The process consists of treating the polymer with a transformation solution comprising a solvent, a lubricant and an alcohol.

[0007] Document CA2739698 describes a process for reducing the volume of polystyrene foam using a solvent. Description of the invention

[0008] An object of the invention is to provide an installation for transforming a polymer, in particular of the expanded polystyrene type, using a reagent, from an expanded solid state to an unexpanded amorphous state to obtain a magma of pasty and flexible consistency.

[0009] To achieve this, the installation includes:

[0010] a receiving chamber for receiving the polymer to be transformed;

[0011] a grinding device for grinding the polymer;

[0012] a reagent reservoir;

[0013] a treatment chamber comprising a spraying device for spraying the reagent onto the ground polymer in order to obtain a magma;

[0014] a separation chamber comprising a wringing device to wring the magma in order to extract a liquid containing the reagent, called the extracted liquid, and obtain a wrung magma;

[0015] a first evacuation device for removing the drained magma from the separation chamber; and

[0016] a second evacuation device, separate from the first evacuation device, to evacuate the extracted liquid out of the separation enclosure.

[0017] The reagent may be similar to that described in document WO99 / 07776, namely a transformation solution comprising a solvent, a lubricant, and an alcohol. By way of non-limiting example, the solvent may be acetin, the lubricant may be glycerin, and the alcohol may be 95% ethyl alcohol.

[0018] The polymer to be transformed is, for example, expanded polystyrene, which may be in the form of pieces or blocks. By way of example, expanded polystyrene may be that used for shock-absorbing packaging or food packaging.

[0019] It may also be polystyrene from deconstruction.

[0020] The polymer to be processed is placed in the receiving chamber by an operator. The grinding device, preferably located in the receiving chamber, grinds the polymer to obtain a ground polymer. For example, when the polymer to be processed is expanded polystyrene, the ground polymer will be ground expanded polystyrene consisting of small fragments of expanded polystyrene.

[0021] The reagent is sprayed onto the crushed polymer fragments in the treatment chamber by means of the spraying device connected to the reagent reservoir.

[0022] The chemical reaction has the effect of transforming the ground polymer into a substance called magma.

[0023] According to the invention, the magma is then dewatered in the separation chamber using the dewatering device. The dewatering step extracts a liquid containing the reagent from the magma. This liquid can be the reagent itself, that is, the remaining reagent that did not react with the ground polymer. This yields a dewatered magma on the one hand, and the extracted liquid on the other.

[0024] By drained magma, we preferably mean a substance containing less than 20% by mass of reagent.

[0025] The drained magma is evacuated from the separation chamber via the first evacuation device, while the liquid extracted from the magma is evacuated from the separation chamber via the second evacuation device.

[0026] The first and second evacuation devices preferably comprise orifices.

[0027] The drained magma can then be advantageously used to make glue, agglomerate, or any other product using magma.

[0028] Without departing from the scope of the present invention, the installation can be used with other types of polymers, such as styrenic copolymers.

[0029] Advantageously, the installation according to the invention further includes a conveyor for bringing the ground polymer from the receiving enclosure to the processing enclosure, said conveyor preferably extending at least partially into the processing enclosure.

[0030] Preferably the conveyor extends both into the receiving enclosure and into the processing enclosure.

[0031] According to a preferred embodiment, the conveyor rotates around a conveyor axis. It is preferably equipped with a worm screw.

[0032] Furthermore, preferably, the conveyor is inclined relative to the horizontal so that the processing enclosure is positioned lower than the receiving enclosure.

[0033] The treatment chamber is therefore lower than the receiving chamber. This inclination facilitates the transfer of the ground polymer from the receiving chamber to the treatment chamber.

[0034] Advantageously, the grinding device comprises at least one grinding roller which is rotating around a first axis of rotation.

[0035] The grinding roller has a plurality of radial teeth to break down the polymer blocks to be transformed.

[0036] Preferably, the grinding device comprises two grinding rollers arranged side by side, and above the conveyor.

[0037] Advantageously, but not exclusively, the conveyor axis is substantially parallel to the first axis of rotation.

[0038] Advantageously, the spraying device comprises at least one spray nozzle connected to the reagent reservoir. The spray nozzle is located in the treatment chamber, preferably above the conveyor.

[0039] Preferably, the spraying device comprises several spray nozzles connected to the reagent reservoir.

[0040] Advantageously, the installation according to the invention further comprises a hydraulic circuit connected to the spraying device and the reagent tank, the second evacuation device communicating with said reagent tank, whereby, in operation, the extracted liquid exiting the separation chamber flows into the reagent tank.

[0041] It is therefore understood that the extracted liquid, which consists essentially of reagent, is advantageously recovered and reinjected into the treatment chamber. The invention thus makes it possible to reduce reagent consumption by reusing the reagent extracted from the magma, which has therefore not reacted with the polymer.

[0042] According to a preferred embodiment, the treatment enclosure is arranged above the separation enclosure, the treatment enclosure having an outlet communicating with an inlet of the separation enclosure, preferably via a junction conduit.

[0043] Preferably, the outlet is an opening made on a back wall of the treatment enclosure.

[0044] The junction pipe preferably has a frustoconical shape whose cross-section decreases towards the separation chamber

[0045] It is understood that the magma is transferred from the treatment chamber to the separation chamber by falling under the action of gravity. Without departing from the scope of the invention, transfer means could be provided to facilitate the transfer of the magma from the treatment chamber to the separation chamber.

[0046] Advantageously, the first discharge device and the second discharge device are arranged at two opposite ends of the separation chamber. The discharge of the drained magma and the extracted liquid takes place in two positions axially distant from each other.

[0047] Preferably, the first and second evacuation devices are arranged axially on either side of the entrance to the separation enclosure.

[0048] Advantageously, the separation chamber further comprises a rotating conveyor element having a direction of movement to bring the magma towards the dewatering device.

[0049] The extracted liquid that exits the wringing device flows along the conveyor element towards the second discharge device.

[0050] Preferably, the conveyor element rotates around an axis of rotation which is inclined with respect to the horizontal, so that the second discharge device is arranged lower than the wringing device.

[0051] This arrangement facilitates the flow of the extracted liquid towards the second evacuation device, while the conveyor moves the magma towards the dewatering device.

[0052] Preferably, the second evacuation device is therefore arranged lower than the spin-drying device.

[0053] According to a preferred embodiment, the spinning device comprises a spinning head connected to the conveyor element, and a die having a housing receiving the spinning head, the first evacuation device having a first outlet orifice communicating fluidly with the housing.

[0054] It is understood that the magma flows between the wringing head and the matrix where it is crushed in order to be wrung out. The wrung-out magma then flows by gravity towards the first discharge device.

[0055] The spin head is mobile in rotation within the die, preferably driven by the rotation of the conveyor element.

[0056] Preferably, the wringing head comprises a conical surface having at least one helical groove, the matrix having a conical inner wall complementary to that of the conical surface, by which the magma is wrung out by flowing between the helical groove and the conical inner wall of the matrix.

[0057] Without departing from the scope of the present invention, the spin head may include several helical grooves formed on the conical surface of the spin head.

[0058] Alternatively, the dewatering device does not include a dewatering head but only a conical matrix having a conical inner wall against which the magma is compressed by the thrust exerted by the conveyor element. The compression of the magma against the conical wall has the effect of dewatering the magma, which then flows by gravity out of the separation chamber through the first discharge device.

[0059] The first discharge device is preferably located at an axial end of the die or the spin head, opposite the conveying element.

[0060] Advantageously, the installation according to the invention further comprises a receptacle cooperating with the first evacuation device to recover the drained magma.

[0061] The receptacle is, for example, a barrel.

[0062] The installation includes a removable connection element for connecting the barrel in a watertight manner to the first evacuation device. Description of the drawings

[0063] The invention will be better understood upon reading the following description of embodiments of the invention given by way of non-limiting examples, with reference to the accompanying drawings, in which:

[0064] [Fig-1] Fig. 1 is a cross-sectional view of an example embodiment of the installation according to the invention;

[0065] [Fig.2] The [Fig.2] is a top view of the installation of the [Fig.1];

[0066] [Fig.3] Fig.3 is a detailed view of the separation device of the installation the [Fig. 1]; and

[0067] [Fig.4] The [Fig.4] is a cross-sectional view of a variant of the separation device. Detailed description

[0068] Figure 1 illustrates an example of the implementation of an installation 10 according to the invention for transforming a polymer, in particular expanded polystyrene. using a reagent R, from an expanded solid state to an unexpanded amorphous state to obtain a magma of pasty and flexible consistency.

[0069] In [Fig. 1], the installation 10 is shown in longitudinal section, which displays the main constituent elements of the installation. The installation 10 comprises a frame 12 supporting the various constituent elements of the installation 10. The installation 10 includes a receiving chamber 14 located in the upper part of the installation 10. This receiving chamber 14 is intended to receive the polymer P to be processed.

[0070] In this example, the polymer P to be transformed consists of pieces of expanded polystyrene. The receiving enclosure 14 is in the form of a hopper in which a grinding device 16 is arranged to grind the polymer P.

[0071] As can be seen in [Fig.2], the grinding device 16 comprises a first grinding roller 18, and a second grinding roller 20 arranged side by side, the first grinding roller 18 being rotating about a first axis of rotation A. The second grinding roller 20 is, for its part, rotating about a second axis of rotation B.

[0072] As can be seen in [Fig. 2], the first and second axes of rotation A, B are parallel. The first and second grinding rollers 18, 20 are equipped with wings 18a and 20a which extend radially from the first and second axes of rotation A, B.

[0073] It is therefore understood that the pieces of expanded polystyrene introduced into the receiving chamber are crushed by the first and second crushing rollers 18, 20 and fall by gravity below the crushing device. In this example, as illustrated in [Fig. 1], the installation 10 further includes a conveyor 30 below the crushing device 16; the conveyor 30 rotates around a conveyor axis C. In this example, the conveyor 30 is equipped with a screw conveyor 31.

[0074] As can be seen in [Fig. 2], the conveyor 30 is inclined with respect to the horizontal. Furthermore, the conveyor axis C is substantially parallel to the first axis of rotation A of the first grinding roller 18. It can be seen that the first grinding roller 18 is inclined with respect to the horizontal.

[0075] The installation 10 also includes a reservoir 40 of reagent R. In this example, reagent R comprises a solvent, a lubricant, and an alcohol. Preferably, but not exclusively, the reagent may, for example, be similar to that described in document WO99 / 07776, namely a transformation solution comprising a solvent, a lubricant, and an alcohol. By way of non-limiting example, the solvent may be acetin, the lubricant may be glycerin, while the alcohol may be 95% ethyl alcohol.

[0076] Installation 10 also includes a treatment chamber 50, visible in Figures 1 and 3, which has a substantially cylindrical shape. It can be seen that Conveyor 30 extends into the processing chamber 50. In this example, the diameter of conveyor 30 is approximately equal to the diameter of the processing chamber 50. Since conveyor 30 is inclined relative to the horizontal, the processing chamber 50 is located lower than the receiving chamber 14. More precisely, the processing chamber is located lower than the receiving chamber 16. It is understood that the shredded polystyrene produced by the shredding device is conveyed by conveyor 30 into the processing chamber 50.

[0077] The treatment enclosure 50 further comprises a spraying device 52 comprising a first spray nozzle 52a and a second spray nozzle 52b which are axially separated from each other and which are located on an upper part 50a of the treatment enclosure 50.

[0078] The spray device 52 is designed to spray the reagent R onto the ground polymer in the treatment chamber to obtain a magma M through a chemical reaction between the ground polymer and the reagent. To achieve this, the first and second nozzles 52, 52b of the spray device are connected to the reagent reservoir 40 via a hydraulic circuit 54. As illustrated in Figures 1 and 3, the hydraulic circuit 54 comprises piping extending from the reservoir 40 to the spray nozzles 52a and 52b. A mechanical gear pump 57, known elsewhere, can be used to circulate the reagent in the hydraulic circuit.

[0079] The upper part 50a of the treatment enclosure 50 further includes an opening 50b for accessing, if necessary, the inside of the treatment enclosure 50.

[0080] The installation 10 comprises a separation chamber 60 which, in this example, is arranged below the treatment chamber 50. The treatment chamber 50 comprises an outlet 51 formed in the lower part 50d of the treatment chamber. This outlet 51 communicates with an inlet 61 of the separation chamber 60 via a connecting conduit 62. This connecting conduit 62 comprises an upper portion 62a of substantially cylindrical shape which continues into a lower, frustoconical portion 62b.

[0081] In this example, the magma M flows by gravity through the junction pipe 62 from the treatment chamber 50 to the separation chamber 60.

[0082] The separation chamber 60 also includes a dewatering device 70 whose function is to dewater the magma in order to extract a liquid L containing the reagent, which is called the extracted liquid, and to obtain a dewatered magma ME. The dewatered magma is then discharged from the separation chamber via a first discharge device 72. In this example, the first discharge device 72 has an opening 72a which is connected to a connection device 72b arranged to be mounted at an upper part 80a of a barrel 80. It is therefore understood that the drained magma ME falls by gravity into the barrel 80 after the draining stage.

[0083] The separation chamber 60 includes a conveyor element 64 comprising a screw conveyor 65 for conveying the magma towards the dewatering device 70. The conveyor element 64 rotates about an axis of rotation D by means of a motor 100. The conveyor element has a direction of movement symbolized by the arrow S, illustrating the direction of movement of the magma towards the dewatering device 70. As can be seen in [Fig. 3], the axis of rotation D is inclined with respect to the horizontal. The dewatering device is located downstream of the inlet 61 considered along the direction of movement S.

[0084] The installation also includes a second discharge device 90, separate from the first discharge device 72a, for removing the extracted liquid from the separation chamber. Figure 3 shows that the second discharge device 90 is positioned lower than the dewatering device 70. Since the axis of rotation D of the conveyor element is inclined relative to the horizontal, the extracted liquid L flows in the opposite direction to the direction of travel. The extracted liquid therefore flows by gravity to the second discharge device 90 to be removed from the separation chamber via a hydraulic circuit 95. The circuit 95 is connected to the reservoir 40. Thus, during operation, the liquid exiting the separation chamber flows into the reagent reservoir 40.In this example, the extracted liquid consists mainly of reagent R, so the excess reagent that has not reacted with the ground polymer is advantageously recovered and then reinjected into the treatment chamber.

[0085] It can be seen that the first discharge device 72a, which allows the drained magma to be discharged from the separation chamber, and the second discharge device 92, for discharging the extracted liquid from the separation chamber, are located at two opposite ends of the separation chamber. In the example of [Fig. 3], the dewatering device comprises a matrix 71 having a frustoconical inner wall, such that the magma pushed into the matrix 71 by the action of the conveyor element is compressed due to the reduction in diameter, which has the effect of dewatering the magma M. Furthermore, the thrust exerted by the conveyor element has the effect of pushing the dewatered magma ME out of the separation chamber via the first discharge device.

[0086] Figure 4 illustrates a variant of the spin-drying device 70 which differs from the example in Figure 3 in that the spin-drying device 70' comprises a spin-drying head 74' which is connected to the conveyor element 64. In other words, the rotation of the conveyor element 64 around the axis D causes the spin-drying head 74' to rotate. In this example, the spin-drying device 70' also comprises a matrix 71' having a housing 76'. In the example of [Fig.4], the spin head 74' has a conical surface 74a' having one or more helical grooves 75'.

[0087] The matrix has a conical inner wall 71a' which is complementary to that of the conical surface, by which the magma is drained by flowing between the helical groove 75' and the conical inner wall of the matrix 71'.

Claims

Demands

1. An installation (10) for transforming a polymer, in particular expanded polystyrene, using a reagent (R), from an expanded solid state to an unexpanded amorphous state to obtain a magma of pasty and flexible consistency, said installation comprising: a receiving chamber (14) for receiving the polymer (P) to be transformed; a grinding device (16) for grinding the polymer (P); a reagent (LR) reservoir (40); a treatment chamber (50) comprising a spraying device (52) for spraying the reagent onto the ground polymer to obtain a magma; a separation chamber (60) comprising a dewatering device (70) for dewatering the magma to extract a liquid (L) containing the reagent, referred to as the extracted liquid, and to obtain a dewatered magma; a first evacuation device (72a) to evacuate the drained magma out of the separation enclosure;and a second evacuation device (90), separate from the first evacuation device (72a), for evacuating the extracted liquid (L) out of the separation enclosure.;

2. Installation according to claim 1, further comprising a conveyor (30) for bringing the ground polymer from the receiving enclosure to the processing enclosure, said conveyor (30) preferably extending at least partially into the processing enclosure.

3. Installation according to claim 2, wherein the conveyor (30) is rotatable about a conveyor axis (C).

4. Installation according to claim 2 or 3, wherein the conveyor (30) is inclined with respect to the horizontal so that the processing enclosure (50) is arranged lower than the receiving enclosure (14).

5. Installation according to any one of claims 2 to 4, wherein the conveyor (30) is provided with a screw conveyor (31).

6. Installation according to any one of the preceding claims, wherein the grinding device comprises at least one grinding roller (18,20) which is rotatable about a first axis of rotation (A).

7. Installation according to claims 3 and 6, wherein the conveyor axis (C) is substantially parallel to the first axis of rotation (A).

8. Installation according to any one of the preceding claims, wherein the spraying device (52) comprises at least one spray nozzle (52a, 52b) connected to the reagent reservoir.

9. An installation according to any one of the preceding claims, further comprising a hydraulic circuit (54) connected to the spraying device and the reagent tank (40), the second discharge device (90) communicating with said reagent tank, whereby, in operation, the extracted liquid exiting the separation chamber flows into the reagent tank (40).

10. An installation according to any one of the preceding claims wherein the separation enclosure is disposed below the treatment enclosure (50), the treatment enclosure (50) having an outlet (51) communicating with an inlet (61) of the separation enclosure (60), preferably via a connecting conduit (62).

11. An installation according to any one of the preceding claims, wherein the first evacuation device and the second evacuation device are arranged at two opposite ends of the separation enclosure.

12. Installation according to any one of the preceding claims, wherein the separation enclosure (60) further comprises a rotating conveyor element (64) for bringing the magma to the dewatering device (70).

13. Installation according to claim 12, wherein the conveyor element is rotatable about an axis of rotation (D) which is inclined with respect to the horizontal, so that the second discharge device (90) is disposed lower than the wringing device (70).

14. Installation according to claim 12 or 13, wherein the spinning device (70) comprises a spinning head (74') connected to the conveyor element, and a die having a housing receiving the spinning head, the first discharge device comprising a first outlet orifice communicating fluidly with the housing.

15. Installation according to claim 14, wherein the wringing head (74') comprises a conical surface (74a') having at least one helical groove (75), the matrix having a conical inner wall (71a') complementary to that of the conical surface, by which the magma is wrung out by flowing between the helical groove (75') and the conical inner wall of the matrix.

16. Installation according to any one of the preceding claims, further comprising a receptacle (80) cooperating with the first evacuation device to recover the drained magma.

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