Process for recycling used air treatment filters

Abstract

The present invention relates to a method for recycling used air treatment filters comprising a step of collecting (S1) used air treatment filters, each collected used air treatment filter comprising a filter media; a step of grinding (S2) the filter media of the collected used air treatment filters so as to form filter media grinds, also called filter media grinds or filter media chips; and a step of thermally insulating (S3) an area to be thermally insulated with a thermal insulation material comprising at least the filter media grinds obtained during the grinding step. Figure 1

Description

Title of the invention: Method for recycling used air treatment filters Technical field

[0001] The present invention relates to the field of air treatment filters, and more particularly to that of the recycling of such air treatment filters. State of the art

[0002] Air handling units, whether single-flow, double-flow or constant-blowing and whether intended to equip tertiary, industrial or residential premises, and air handling terminal units are equipped with air handling filters which are intended to treat, purify and clean a flow of air circulating in said air handling units or air handling terminal units, and more particularly to capture dust and various harmful particles transported by the air flow.

[0003] An air treatment filter tends, over time, to become clogged and therefore to become blocked, which is likely to impair the efficiency and operation of the air treatment unit or the air treatment terminal unit with which it is associated.

[0004] It is therefore necessary to regularly replace the air treatment filter(s) equipping an air treatment unit or a terminal air treatment unit.

[0005] Currently, such used air treatment filters are collected as ordinary industrial waste (OIW) and are then generally dumped without being recovered or recycled. Summary of the invention

[0006] The present invention aims to remedy this drawback.

[0007] The technical problem underlying the invention consists in particular in providing a method for recycling used air treatment filters which makes it possible in particular to recover such used air treatment filters.

[0008] To this end, the invention relates to a method for recycling used air treatment filters comprising the following steps:

[0009] - collection of used air treatment filters, also called air filters, each collected used air treatment filter comprising a filter media,

[0010] - grinding of filter media from used air treatment filters collected from way of forming filter media shreds, also called filter media chips, and

[0011] - thermal insulation of an area to be thermally insulated, for example of a housing, with a thermal insulation material comprising at least the crushed filter media obtained during the crushing stage.

[0012] The use of a thermal insulation material formed at least in part from crushed filter media makes it possible to recover used air treatment filters, to limit the environmental impact of the manufacture of air treatment filters, and also to avoid, or at least limit, the use of other raw materials to produce the thermal insulation material.

[0013] The recycling method according to the present invention may further have one or more of the following characteristics, taken alone or in combination.

[0014] According to one embodiment of the invention, the thermal insulation step is a step of bulk thermal insulation of the area to be thermally insulated with a bulk thermal insulation material comprising at least the crushed filter media obtained during the grinding step.

[0015] According to one embodiment of the invention, the collected used air treatment filters are dust filters. Advantageously, the collected used air treatment filters comprise bag filters, for example flexible or rigid bag filters, and / or pleated filters, and / or thread-sewn filters, also called fan coil filters.

[0016] According to one embodiment of the invention, the used air treatment filters collected come from air treatment units, for example single-flow or double-flow, and / or from terminal air treatment units.

[0017] According to one embodiment of the invention, the area to be thermally insulated may be an attic, a sub-floor, an intermediate floor, also called a floor, or even a wall.

[0018] According to one embodiment of the invention, the bulk thermal insulation step comprises a step of spraying by blowing the bulk thermal insulation material into the area to be thermally insulated. However, according to an alternative embodiment of the invention, the bulk thermal insulation step could comprise a step of spreading the bulk thermal insulation material into the area to be thermally insulated.

[0019] According to another embodiment of the invention, the recycling method comprises a step of compacting the crushed filter media so as to form thermal insulation panels. According to such an embodiment of the invention, the thermal insulation material is formed by the thermal insulation panels, and the thermal insulation step consists of positioning the thermal insulation panels in the area to be thermally insulated.

[0020] According to one embodiment of the invention, the recycling method comprises a step of packaging the thermal insulation panels in roll form.

[0021] According to one embodiment of the invention, the filter media of the collected used air treatment filters comprise filter media made of fiberglass, and for example microfiberglass, and / or filter media made of synthetic fiber, for example polyester-based, and comprise for example exclusively filter media made of fiberglass and filter media made of synthetic fiber.

[0022] According to one embodiment of the invention, the crushed filter media obtained during the grinding step have maximum dimensions of less than 16 mm, and for example less than 14 mm and advantageously less than or equal to approximately 12 mm.

[0023] According to one embodiment of the invention, the grinding step is carried out at least in part by a grinding machine, such as a grinder-refiner, comprising a sieve, also called a sieve grid, comprising meshes, also called passage openings, having a mesh size of between 8 and 16 mm, advantageously of between 10 and 14 mm, and for example of approximately 12 mm.

[0024] According to one embodiment of the invention, the used air treatment filters collected during the collection step comprise used air treatment filters of different types, and for example used air treatment filters comprising filter media of different types.

[0025] According to one embodiment of the invention, the filter media of the collected used air treatment filters comprise at least filter panels, filter bags and / or pleated filter media.

[0026] According to one embodiment of the invention, the filter media of the collected used air treatment filters comprise self-supporting filter media and filter media equipped with reinforcing grids, for example metallic.

[0027] According to one embodiment of the invention, the used air treatment filters collected during the collection step comprise used air treatment filters of a first type, each used air treatment filter belonging to the first type comprising a filter medium and a support frame to which the respective filter medium is fixed. The support frame of a used air treatment filter of the first type may be metallic, for example made of steel (especially galvanized steel) or aluminum, be made of plastic, for example made of ABS, be made of cardboard or even be made of wood.

[0028] According to one embodiment of the invention, the grinding step comprises:

[0029] - a first grinding step, also called a pre-grinding step, consisting to pre-grind the collected used air treatment filters, so as to obtain pre-grinds of support frames and pre-grinds of filter media,

[0030] - a separation step consisting of separating the pre-ground filter media from the pre-crushed support frames, and

[0031] - a second grinding step, also called a grinding refining step, consisting of grinding the pre-ground filter media to form ground filter media.

[0032] According to another embodiment of the invention, the recycling method comprises, prior to the grinding step, a separation step, and for example a mechanical separation step, consisting of separating the filter media from their support frames.

[0033] According to one embodiment of the invention, the used air treatment filters collected during the collection step comprise used air treatment filters of a second type, each used air treatment filter belonging to the second type comprising only one filter medium, and therefore being devoid of a support frame. Thread-sewn filters are, for example, part of the used air treatment filters of the second type.

[0034] According to one embodiment of the invention, the recycling method comprises a step of packaging the crushed filter media in bags.

[0035] According to one embodiment of the invention, the recycling method comprises a step of washing the filter media and / or a step of washing the crushed filter media.

[0036] According to one embodiment of the invention, the washing step is carried out by bringing the filter media and / or the filter media ground material into contact with a cleaning liquid.

[0037] The present invention further relates to a use of filter media shreds, obtained by shredding filter media from used air treatment filters, for thermally insulating an area to be thermally insulated. In other words, the present invention relates to a use of filter media shreds, obtained by shredding filter media from used air treatment filters, as a thermal insulation material, and for example as a bulk thermal insulation material.

[0038] The present invention also relates to a thermal insulation material, and for example a bulk thermal insulation material, comprising crushed filter media obtained by crushing filter media from used air treatment filters.

[0039] According to one embodiment of the invention, the thermal insulation material, and for example the bulk thermal insulation material, is mainly, and for example only, made up of crushed filter media. Brief description of the figures

[0040] The aims, aspects and advantages of the present invention will be better understood from the description given below of two embodiments of the invention presented as non-limiting examples, with reference to the appended drawings in which:

[0041] [Fig. 1] is a diagram showing the steps of a method for recycling used air treatment filters according to the present invention.

[0042] [Fig.2] is a perspective view of two used air treatment filters of a first type.

[0043] [Fig. 3] is a perspective view of a used air treatment filter of a second type.

[0044] [Fig.4] is a perspective view of filter media shreds. Detailed description

[0045] The present invention relates to a method for recycling used air treatment filters 2 according to one embodiment of the invention.

[0046] The recycling process includes in particular:

[0047] - a collection step SI consisting of collecting used air treatment filters 2 originating at least in part from air treatment plants, for example single-flow, double-flow or constant-blowing, and / or from terminal air treatment units, the collected used air treatment filters may for example comprise used air treatment filters 2 of different types, and in particular comprise used air treatment filters 2 provided with filter media of different types,

[0048] - a grinding step S2 consisting of grinding the filter media 3 of the filters of treatment of collected used air, so as to form filter media shreds, also called filter media chips, and

[0049] - a thermal insulation step S3 consisting of thermally insulating a zone to be thermally insulated, for example a dwelling, with a thermal insulation material comprising at least, and for example only, the crushed filter media obtained during the crushing step S2.

[0050] According to one embodiment of the invention, the used air treatment filters 2 collected during the collection step SI comprise in particular bag filters, for example flexible bag filters or rigid bag filters, and pleated filters, but may also comprise any other type of air treatment filter provided with a filtering medium 3.

[0051] The used air treatment filters 2 collected during the collection step SI comprise in particular used air treatment filters 2 of a first type and used air treatment filters 2 of a second type, each used air treatment filter 2 belonging to the first type comprising a filtering medium 3 and a frame support frame 4 to which the respective filter medium 3 is attached, and each used air treatment filter 2 belonging to the second type comprising only a filter medium 3 and therefore being devoid of a support frame 4 (a thread-sewn filter is an example of a used air treatment filter belonging to the second type). The support frame 4 of a used air treatment filter 2 of the first type may be metallic, and for example made of steel (in particular galvanized steel) or aluminum, be made of plastic, and for example ABS, be made of cardboard or even be made of wood.

[0052] Advantageously, the filter media 3 of the used air treatment filters 2 collected during the collection step SI comprise filter media 3 made of fiberglass, and for example microfiberglass, and / or filter media 3 made of synthetic fiber, for example polyester-based. According to one embodiment of the invention, the filter media 3 of the used air treatment filters 2 collected during the collection step SI comprise self-supporting filter media and also filter media equipped with reinforcing grids, for example metal.

[0053] Advantageously, the used air treatment filters 2 can for example be collected from building maintenance companies and / or industrial maintenance companies.

[0054] According to one embodiment of the invention, the grinding step S2 is carried out at least in part with a grinding machine, such as a grinder-refiner, comprising a sieve comprising meshes (for example of square, rectangular, circular or any other shape) having a mesh size of between 8 and 16 mm, advantageously between 10 and 14 mm, and for example of approximately 12 mm. Such a grinding machine makes it possible to obtain ground filter media advantageously having maximum dimensions less than or equal to approximately 12 mm, which ensures optimal thermal insulation of the area to be thermally insulated.

[0055] According to one embodiment of the invention, the grinding step S2 comprises:

[0056] - a first grinding step, also called a pre-grinding step, consisting to pre-grind the collected used air treatment filters, so as to obtain pre-grinds of support frames and pre-grinds of filter media,

[0057] - a separation step consisting of separating the pre-ground filter media from the pre-crushed support frames, and

[0058] - a second grinding step, also called grinding refining step, consisting of grinding the pre-ground filter media to form ground filter media.

[0059] According to another embodiment of the invention, the recycling method could comprise, prior to the grinding step S2, a separation step, and for example a mechanical separation step, consisting, for the treatment filters of the first type, to separate the filter media 3 from their support frames 4, and the grinding step S2 would then consist only of grinding the filter media 3 of the different types of used air treatment filters 2 so as to form ground filter media.

[0060] According to one embodiment of the invention, the thermal insulation material is a bulk thermal insulation material, and the thermal insulation step S3 is a step of bulk thermal insulation of the area to be thermally insulated with the bulk thermal insulation material.

[0061] According to one embodiment of the invention, the area to be thermally insulated during the thermal insulation step S3 may be an attic, a sub-floor, an intermediate floor, also called a floor of a storey, or even a wall. The thermal insulation step S3 may for example be carried out by spraying by blowing or by spreading the bulk thermal insulation material, and therefore the crushed filter media, in the area to be thermally insulated.

[0062] According to one embodiment of the invention, the thermal insulation material used during the thermal insulation step S3 is mainly, and for example only, made up of crushed filter media, and is advantageously free of additive.

[0063] According to one embodiment of the invention, the recycling method according to the present invention could further comprise:

[0064] - a washing step consisting of washing the filter media 3 and / or ground materials filter media with a cleaning fluid, such as isopropyl alcohol, and

[0065] - a conditioning step consisting of conditioning the media shreds filters obtained during grinding step S2 in bags.

[0066] According to an alternative embodiment of the invention, the recycling method could comprise a step of compacting the crushed filter media so as to form thermal insulation panels, and the thermal insulation step S3 could consist of thermally insulating the area to be thermally insulated with the thermal insulation panels as thermal insulation material. According to such an embodiment of the invention, the recycling method could comprise a step of packaging the thermal insulation panels in roll form.

[0067] Of course, the invention is in no way limited to the embodiments described and illustrated which have been given only as examples. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Claims

1. A method for recycling used air treatment filters (2) comprising the following steps: - collecting used air treatment filters (2), each collected used air treatment filter comprising a filter media (3), - grinding the filter media (3) of the collected used air treatment filters so as to form ground filter media, and - thermally insulating an area to be thermally insulated with a thermal insulation material comprising at least the ground filter media obtained during the grinding step.

2. A recycling method according to claim 1, wherein the thermal insulation step is a bulk thermal insulation step of the area to be thermally insulated with a bulk thermal insulation material comprising at least the filter media shreds obtained during the grinding step.

3. A recycling method according to claim 1 or 2, wherein the filter media (3) of the collected used air treatment filters comprise filter media (3) made of glass fiber, and / or filter media (3) made of synthetic fiber.

4. Recycling method according to any one of claims 1 to 3, in which the crushed filter media obtained during the crushing step have maximum dimensions of less than 16 mm.

5. A recycling method according to any one of claims 1 to 4, wherein the grinding step is carried out at least in part by a grinding machine comprising a sieve having meshes having a mesh size of between 8 and 16 mm.

6. A recycling method according to any one of claims 1 to 5, wherein the used air treatment filters collected during the collection step comprise used air treatment filters (2) of different types.

7. A recycling method according to claim 6, wherein the used air treatment filters collected during the collecting step comprise used air treatment filters (2) of a first type, each used air treatment filter belonging to the first type comprising a filter medium (3) and a support frame to which the respective filter medium (3) is attached.

8. A recycling method according to claim 7, wherein the grinding step comprises: - a first grinding step of pre-grinding the collected used air treatment filters, so as to obtain support frame pre-grinds and filter media pre-grinds, - a separation step of separating the filter media pre-grinds from the support frame pre-grinds, and - a second grinding step of grinding the filter media pre-grinds so as to form filter media grinds.

9. A recycling method according to claim 7 or 8, wherein the used air treatment filters collected during the collection step comprise used air treatment filters (2) of a second type, each used air treatment filter belonging to the second type comprising only one filter medium (3).

10. A recycling method according to any one of claims 1 to 9, which comprises a step of packaging the filter media shreds in bags.

11. Thermal insulation material comprising crushed filter media obtained by crushing filter media (3) from used air treatment filters (2).

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