ES2758184A1 - Installation for recycling composite materials with carbon fiber and/or fiberglass reinforcement and procedure for the implementation of the installation. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Installation for recycling of composite materials with carbon fiber and/or fiberglass reinforcement and procedure for the implementation of said installation. The installation comprises a vertical reactor with a single treatment chamber (6), inside which there are means of heating the treatment chamber, either by means of electrical resistances or gas burners, a watertight treatment chamber (6), of tubular configuration and vertically elongated, with a material loading zone and an outlet duct (9) for the gases generated in the decomposition of the matrix, with means to selectively redirect the volatiles to a liquefiable gas condenser exchanger or to a decanting before filtering, while in correspondence with its lower area it includes some injectors (7) for gasifying the material that make up the matrix of the material, as well as an outlet gate for the recovered reinforcement material towards a collection container (8), assisted by a cooling means. (Machine-translation by Google Translate, not legally binding)

Description

D E S C R I P C I Ó N

Installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement and procedure for implementing the installation.

TECHNICAL SECTOR

The present invention refers to a facility for recycling composite materials with carbon fiber and / or fiberglass reinforcement, where said reinforcement is contained in a matrix next to which said composite material forms.

The invention is therefore situated in the field of the recycling industry.

The object of the invention is to provide a recycling facility for this type of materials with a simpler structure than conventional facilities, compact, and highly efficient, all with a lower cost of implementation.

The invention also affects the industrial process carried out within the installation.

BACKGROUND OF THE INVENTION

Composite materials are those that consist of two or more components, the properties of said composite material being superior to those of the separate constituent materials.

Composite materials are made up of two phases, a continuous phase called the matrix and another dispersed phase called the reinforcement. The reinforcement provides the mechanical properties to the composite material while the matrix provides the thermal and chemical resistance. The matrix and the reinforcement are separated by the interface.

The composite materials market is experiencing continuous growth every year, so in addition to being materials that are increasingly present in our lives are also more present as waste once their useful life has ended.

To obtain the highest quality in the recycling of the constituents, it is necessary to recover the material in the closest possible state to the original. Therefore, in the case of fibers from continuous fiber composite materials, it is necessary to recover the fibers with total absence of residues from the matrix, so that an exploitation of said fibers is possible.

The two most widely used methods of recycling composite materials today are mechanical recycling, which destroys most of the properties of the base material, and incineration, which only allows energy recovery.

In this sense, in the patent of invention EP0750944, an ultra-high energy impact system is described to reduce the particle size of the composite materials in a process of recycling them, up to an average diameter as small as approximately 40 ^ m, which comprises a cooling station to cool said material to a temperature within the range of about -40 ° F to about -450 ° F, a grinding station to reduce the particle size of the materials of said cooling, where Said grinding station includes a rotor operating at a peak speed within the range of about 600 to about 1500 feet per second and, an atmosphere modifier for modifying the gaseous atmosphere within said grinding station.

In this case, a crushing system of materials previously cooled to a temperature below the glass transition temperature of the material before being crushed is described. During crushing, the materials are crushed into particles of roughly the same size. In this way, it is possible to completely grind the material into fine particles.

Thus, this device does not allow a subsequent separation of the crushed materials. In addition, the very low necessary cooling temperatures generate high process costs.

Furthermore, reference document US2016039118 defines a pyrolysis plant for the recovery of carbon fibers from composite materials. This pyrolysis plant comprises an elongated pyrolysis furnace for continuous pyrolysis of material that works continuously during operation, an inlet station for introducing material to be processed into the pyrolysis furnace at one end, an outlet station for discharge which recovers the carbon fiber material from the pyrolysis furnace at its other end, a gas extraction device for pyrolysis gas produced in the pyrolysis furnace, and a control device for the regulation of the individual components at least of the gas in the pyrolysis oven.

This pyrolysis furnace is an indirectly heated rotary tube furnace that has at least the following components: an elongated rotary tube that forms the housing space for the material and is connected to the inlet station and the outlet station, with the rotating tube is provided on its cylindrical wall with outlet openings to discharge the pyrolysis gas formed during the pyrolysis over at least part of its length and, an insulated housing from the outside, which at least in part surrounds the rotating tube and has openings for the entrance station and, optionally, also for the exit station and has discharge lines for the pyrolysis gas.

A plurality of gas sections at different adjustable temperatures are provided in the housing along the length of the rotating tube; wherein the outlet openings in the rotary tube are provided at least in the section that has the highest gas temperature. The pyrolysis furnace has several sections formed by at least one heating zone, a first pyrolysis zone, a second pyrolysis zone and a cooling zone.

The composition of the gas and the temperature in the pyrolysis furnace in the various sections of the rotary tube can be regulated differently, with a defined proportion of oxygen and with a defined temperature in the first pyrolysis zone and with a defined proportion of oxygen. and with a defined temperature in the second pyrolysis zone.

In this case, we see that oxygen is used in the pyrolysis process, so it requires exhaustive control of the internal atmosphere and temperature to avoid combustion.

Likewise, in this pyrolysis process, both the entrance of the material, its heating, the exit of the gases, the separation of the fibers and decomposition of the matrix, and the exit of said fibers, are carried out in the same chamber inside the oven, continuously, so that the product to be recycled enters through one end of the chamber and the resulting product exits through the other. This camera is also in continuous rotation.

In this way, since the material is subject to rotation at all times, from the beginning when it is a composite material to the end when it is decomposed into fibers and resins, a lower quality of the final product is generated.

In addition, when the entire process is carried out continuously, the result obtained, since all the material remains in the chamber throughout the process and there is no clear separation between materials with a greater or lesser degree of separation in their constituent elements, is that the product itself in the transition zones from some controlled atmosphere conditions to others intermingles and hinders a greater effectiveness of the process.

For its part, the invention patent P201630474 refers to an installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, where said reinforcement is contained in a matrix next to which said composite material forms, which it comprises a horizontal reactor divided into three independent and watertight zones, arranged in line and separated from each other by respective separation gates that allow the passage of the composite material to be recycled from one previous zone to the next only when the process has finished in said previous zone , where the first zone also includes an inlet gate for the composite material, a rotation mechanism for said composite material and a first means for the exit of the gases generated by the decomposition of the matrix, where the second area comprises air injectors and a few second means of exit of the gases generated by the reaction of the air with the residues of the matrix and, where the The third zone comprises an outlet gate for the reinforcing material and a cooling means for the reinforcing material.

Thus, in said installation multiple independent cameras participate, which makes it present a large volumetry, with a complex structure, in addition to requiring means of dragging the material from one chamber to another, which translates into a expensive installation and difficult to implement.

A similar situation occurs in the case of the invention patent WO 2009090264, in which an installation / method for recycling composite material comprising carbon fibers and a resin is defined.

The installation involves an oven with a heating zone, a conveyor to transport the composite material through the oven; furnace in which controlled oxygen entry is foreseen, so that in it the resin of the composite material is removed, as it travels through the heating portion of the furnace in the conveyor, by chemical decomposition at a first temperature , with the resulting generation of fumes; wherein the fumes generated are removed from the heating portion in a controlled manner, so that the percentage of oxygen in the atmosphere in the heating portion is controlled. Consequently, this installation presents the same problem as that described for document P201630474.

EXPLANATION OF THE INVENTION

The installation for recycling of composite materials with carbon fiber and / or fiberglass reinforcement that is recommended solves the aforementioned problem in a fully satisfactory way, based on a simple but effective solution.

More specifically, the installation allows the recycling of composite materials with carbon fiber and / or fiberglass reinforcement, where said reinforcement is contained in a matrix next to which said composite material forms, being able to treat both complete parts and pieces. of small size, previously divided according to their different variants of implementation.

In any of the cases, the installation of the invention is constituted from a reactor that in the present case, and contrary to what happens conventionally, adopts a vertical arrangement, being formed by a cylindrical cavity that determines a treatment chamber , which is automatically fed from the top and discharged from the bottom.

The reactor also includes a condenser heat exchanger designed to collect the condensable vapors obtained in the first part of the process and a decanter to clean the gases produced in the intermediate stage of the process from volatile impurities.

As previously mentioned, depending on whether the composite material to be recycled is supplied in small pieces, previously fractionated, or in larger pieces, it will be automatically fed through a worm screw that dose and pour the material to be treated inside the treatment chamber, or discrete loads of different sizes will be fed through the upper section.

In accordance with the embodiment in which the reactor is fed through an endless screw, it has been provided that the chamber comprises a permeable plate located above the entrance height of the material, which allows the passage of the volatiles and not of the solids.

In either case, the installation includes a hatch located in the lower part of the treatment chamber, which can be folded down by external means, so that it allows the exit of the treatment chamber of the recycled product to another collection compartment, which includes also a gas installation to avoid contact of the hot product with the outside air or with oxygen.

The cooling means can be materialized in multiple ways, such as a coil cooled by the passage of water, air cooling or by a cooled gas.

For its part, the vertical reactor has a casing made of steel or aluminum at least on its outer surface, duly covered internally by a thermal insulation layer, the cylindrical vertical chamber or treatment chamber, internally and concentrically being of watertight construction.

Outside said treatment chamber, and inside the casing-insulator assembly, heating means are established, which can be materialized in an electric heating system, or a treatment chamber heating system using gaseous fuels through a burner that recirculates gases around the treatment chamber.

Another aspect, according to a preferred embodiment, is the existence of a gas circuit through which the interior of the treatment chamber is fed with a gas (nitrogen and / or oxygen) or gas mixtures through one or more injectors.

In either case, the treatment chamber will have an outlet for evaporated gases arranged in correspondence with its upper area, which includes a branch at its outlet, determining an outlet conduit for the evaporated gases towards a condenser exchanger for liquefied gases and another to a previously filtered settling circuit. The way in which the generated volatiles will circulate will depend on the moment of the cycle and is controlled by a three-way valve.

As for the procedure that is carried out within the installation, this procedure comprises two main phases, which are determined below.

A first phase consists of a complete pyrolysis in which the composite material enters the watertight treatment chamber of the vertical reactor, where it is heated to a temperature between 500 and 700 ° C in a controlled atmosphere with an absence of oxygen. In this first phase the matrix decomposes thermally without burning. Due to the decomposition of the matrix, an output of evaporated gases is generated.

The polymeric matrix of the composite material can be formed by any type of resin or even a polymer, being included in the term "resin" or "polymer", polyester, vinyl ester, epoxy, bisphenolic or melanin.

The reinforcing or reinforcing agent can be constituted by a fiberglass and / or carbon fiber.

Composite materials may contain other components in small proportions, to improve or enhance some of their characteristics or to aid in their formation process, such as accelerators, colorants, fluidizers, catalysts, microspheres, foams, mold release agents, metal components, wood or anti UV.

Thus, the by-products obtained from pyrolysis are condensable liquids as a result of the thermal cracking of the matrix, so depending on the incoming product, phenols, aliphatics, aromatics, etc. can be obtained. The gases obtained in this phase are condensable, for the most part hydrocarbons.

With the advance of the process, at a moment the previous condensables stop being produced and the treatment chamber is fed with a mixture of gases, preferably nitrogen and oxygen or any other reducing or inert gas, producing a gasification of the material that forms matrix.

The gas mixture introduced in this second phase reacts with the matrix residues, generating the exit of gases due to said reaction that will circulate through the filtering and decantation circuit, the material resulting at the end of this part of the cycle being the material reinforcement exclusively.

Subsequently, a second phase that begins once the previously performed process has finished, passing the obtained product to the cooling zone. In this zone, the reinforcement material is cooled by means of cooling means and without contact with the oxygen in the air.

During the process carried out in this phase, the discharge gate for the reinforcing material is kept closed.

From this structuring / process, a significant improvement in the state of the art is obtained.

This is so, with a simple installation (a single area) of small dimensions, the recycling process is carried out in two phases, achieving an efficient separation of the recyclable component and the use of gases.

With all this, it is a recycling facility that is simpler and more efficient than those existing to date, as is the case with carrying out the recycled in said facility.

DESCRIPTION OF THE DRAWINGS

To complement the description that will be made below and in order to help a better understanding of the characteristics of the invention, according to a preferred example of practical embodiment thereof, a set of drawings is included as an integral part of said description. where, by way of illustration and not limitation, the following has been represented:

Figure 1.- Shows a schematic view of a longitudinal section of the installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, made according to the object of the invention, according to a first variant. for the installation, in which the heat generating means of the reactor are electric.

Figure 2.- Shows a schematic view of a section according to an imaginary horizontal plane of the installation of the previous figure.

Figure 3.- Shows a view similar to that of Figure 1, but corresponding to a variant embodiment in which the material to be recycled is supplied in small pieces or fractions, being fed through a hopper-screw assembly. endless.

Figure 4.- Shows a view similar to that of figure 1, but corresponding to an embodiment variant in which the heat generating means in the reactor are materialized in a gas burner.

Figure 5.- Shows a schematic view of a section according to an imaginary horizontal plane of the installation of the previous figure.

Figure 6.- Shows, finally, a view similar to that of Figure 4, but corresponding to a variant embodiment in which the material to be recycled is supplied in small pieces or fractions, being fed through a set hopper-screw endless.

PREFERRED EMBODIMENT OF THE INVENTION

In view of the outlined figures, and especially of Figures 1 and 2, it can be seen as the installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, according to a first variant of the planned embodiment for it, it is constituted from a vertical reactor, in which a casing (3), preferably made of steel or aluminum, with an internal layer of insulating material (4), such as refractory ceramic fiber and / or wool, participates. of mineral rock, casing (3) inside which a watertight treatment chamber (6) is established, with a tubular configuration, vertically elongated and thermally conductive in nature.

The composite material, which can be of different sizes, is introduced into the treatment chamber (6) through the loading area (1), through a cover (2) with its corresponding thermal insulator, which communicates with the upper end of said treatment chamber (6).

In proximity to said upper zone of the treatment chamber (6), an outlet duct (9) is established for the gases generated in the decomposition of the matrix, a duct that has a bifurcation assisted by a three-way valve, which redirects the volatile to a liquefied gas condenser exchanger or to a previously filtered settling circuit, depending on the moment of the cycle in which the reactor is located.

Continuing with the described embodiment example, within the reactor, that is, in the space defined between the treatment chamber (6) and the casing (3) and insulator (4) thereof, a system is established heating by electric resistances (5), responsible for heating the treatment chamber (6).

In proximity to the lower area of said treatment chamber (6), gas injectors (7), preferably nitrogen and oxygen, are established, intended to produce a gasification of the material that makes up the matrix. The injectors (7) will include a flow regulator and a control solenoid valve, with diffusers for more application homogeneous of said gases.

Finally, the treatment chamber (6) is finished off at the bottom in an exit hatch of the reinforcing material recovered in the process to a collection container (8), which will be assisted by cooling means, either a coil cooled by the passage of water that is introduced through a cooling water inlet and after going through the coil cooling the reinforcing material, leaves through a cooling water outlet, recirculating in a closed circuit through an air cooler located outside the ship .

According to a second variant of practical embodiment, the one shown in figure 3, when the material to be recycled is supplied in a small size, previously fragmented, starting from the same basic reactor structure provided for the variant of figures 1 and 2 This can be automatically fed through an external hopper (1 '), which feeds a worm screw (10) that goes through the casing (3) and the insulator (4), extending internally until the material is directly discharged into the treatment chamber (6), and more specifically in the upper area of said treatment chamber (6), having provided that above said discharge area a permeable plate (15) is interposed, which allows the passage of volatiles and does not of the solids, keeping the rest of the components of the reactor analogous to the previously described variant of embodiment, with the exception of the condensable outlet line (9) which will be arranged this time in co correspondence with the upper end of the treatment chamber (6).

At the same time, and according to two other variants of the installation as a function of the feeding means of the composite material, those shown in Figures 4 to 6, the heating means of the treatment chamber (6) could be replaced by gaseous fuel burners, more specifically through a burner (11) that recirculates the gases around the treatment chamber, having for this purpose a chimney (13) for expelling the gases generated by the combustion of said gaseous fuels, being able to take advantage of its residual heat through an exchanger (14) to optimize the process.

As previously stated, the reactor in its variant embodiment in which the heating means of the treatment chamber (6) are materialized in gaseous fuel burners, it may be fed from above, by the loading area (1), through a cover (2) with its corresponding thermal insulator, which communicates with the upper end of said treatment chamber (6), as shown in figure 4, or through a hopper assembly (1 '), worm screw (10), when the material to be recycled is supplied in small items size, as shown in figure 6.

In this way, a very efficient recycling facility and recycling procedure is achieved, the result of which is a high-quality reinforcing material and gases that can be reusable, at a low cost and with great ease of installation.

Claims (12)

1a.- Installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, where said reinforcement is contained in a matrix next to which said composite material forms, characterized in that it is constituted from a vertical reactor, in which a casing (3) participates, with an internal layer of insulating material (4), casing (3) inside which a single watertight treatment chamber (6) is established, with a tubular configuration, vertically elongated and of a thermal nature conductive, it being provided that between the housing (3) -insulator (4) and the treatment chamber (6) assembly heating means of the treatment chamber (6) are established, said treatment chamber (6) including feeding means of the material to be recycled in correspondence with its upper zone, as well as at least one outlet duct (9) for the gases generated in the decomposition of the matrix, with means to selectively redirect the volatiles towards a condenser exchanger of liquefiable gases or to a previously filtered settling circuit, while in correspondence with the lower area of the treatment chamber (6) some injectors (7) for gasification of the material that make up the matrix of the material are established, inferiorly to which the treatment chamber (6) includes an outlet gate for the recovered reinforcing material to a collection container (8), assisted by cooling means. 2a.- Installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, according to claim 1, characterized in that the heating means of the treatment chamber (6) are embodied in a heating system using electrical resistances (5). 3a.- Installation for recycling composite materials with carbon fiber and / or glass fiber reinforcement, according to claim 1, characterized in that the heating means of the treatment chamber (6) are materialized in gaseous fuel burners. 4a.- Installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, according to claim 1, characterized in that the means of feeding the treatment chamber (6) with the material to be recycled materialize in an area load (1), provided with a cover (2) with its corresponding thermal insulator, which communicates with the upper end of the treatment chamber (6). 5a.- Installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, according to claim 1, characterized in that the means of feeding the treatment chamber (6) with the material to be recycled materialize in one external hopper (1 '), which feeds a worm screw (10) that goes through the casing (3) and the insulator (4), extending internally until the material is directly discharged into the treatment chamber (6) in the upper area of the latter , having provided that above said discharge zone a plate permeable (15) to volatiles and impermeable to solids is interposed. 6a.- Installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, according to claim 1, characterized in that the casing (3) is made of steel. 7a.- Installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, according to claim 1, characterized in that the casing (3) is made of aluminum. 8a.- Installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, according to claim 1, characterized in that the insulator (4) is made of refractory ceramic and / or mineral rock wool. 9a.- Installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, according to claim 1, characterized in that the outlet duct (9) for the gases generated in the decomposition of the matrix, has an assisted bifurcation by a three-way valve, which redirects the volatiles to a liquefied gas condenser exchanger or to a previously filtered settling circuit. 10a.- Installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, according to claim 1a, characterized in that the injectors (7) are embodied in nitrogen and oxygen injectors or a mixture of other gases, including a regulator flow and a control solenoid valve. 11a.- Installation for recycling composite materials with carbon fiber and / or fiberglass reinforcement, according to claim 1, characterized in that the cooling means of the collection container (8) are embodied in a coil cooled by water and assisted by an air cooler. 12a.- Procedure for recycling composite materials with carbon fiber and / or fiberglass reinforcement through the installation of claims 1 to 11a, characterized in that the following operational phases are established therein: • A first phase in which the composite material enters the treatment chamber (6) from its upper area, undergoing a pyrolysis process in which it is heated to a temperature between 500 and 700 ° C in a controlled atmosphere in the absence of oxygen and in which the matrix decomposes thermally without combusting, generating an outlet for evaporated gases that rise along the treatment chamber (6), as well as obtaining condensable liquids that fall by gravity towards the lower zone of said treatment chamber, then proceeding to supply the treatment chamber (6) with a mixture of gases, preferably nitrogen and oxygen or any other reducing or inert gas, producing a gasification of the material that makes up the matrix, gases that are redirected to a filter and decantation circuit. • A second phase that begins once the first phase has finished, in which the liquids obtained in the treatment chamber, specifically the reinforcing material, are discharged into a collection container (8), undergoing a cooling process without contact with oxygen in the air.