Air filtration device with filter bags, bag and corresponding mounting and tensioning methods

Abstract

Air filtration device 1 with filter bags 5 comprising: - an upper body 2 from which the air filtered by the device 1 is discharged; - a sedimentation chamber 3 disposed below said upper body 2, and equipped with waste collection means at its lower part; - a vertical filter cartridge 4 comprising a peripheral casing 40 and filter bags 5 extending between said sedimentation chamber 3 and the upper body 2, and attached in the filter cartridge 4 to a lower support structure 6 and to an upper support structure 7; - means for energizing all the filter bags 5 at a predetermined average voltage. Method for mounting and tensioning filter bags 5 in such a device. Corresponding filter bag 5. Installation comprising such a device 1. Drawing: Fig 1

Description

Title of the invention: Air filtration device with filter bags, bag and corresponding mounting and tensioning methods

[0001] The present invention relates to an air filtration device of the filter bag type.

[0002] It also relates to a method of mounting filter sleeves within the device, as well as a method of tensioning said filter sleeves adapted to said device.

[0003] It further relates to a filter sleeve adapted to such a device, and an installation comprising such a device.

[0004] The term air filtration device of the filter bag type refers in particular to a cyclonic pre-separation dust collector for filtering air flows necessary for the transport of pollutants. This dust collector can be integrated into an installation allowing said pollutants to be captured directly at the source and then filtered and recovered. Such a dust collector has been commercially available for years under the trade name “Cyclofiltre®”.

[0005] Such an air filtration device of the filter bag type is described in document FR2856936.

[0006] Document FR2856936 teaches that this type of device ensures the extraction of elements suspended in an atmosphere drawn from particular premises, for example premises for the production, treatment or storage of powdered products, or from certain industries resulting in the emission of waste, such as sawdust or highly volatile shavings.

[0007] This type of device taught in document FR2856936 is made up in a known manner of three main elements generally centered on the same vertical axis: - an upper body, cylindrical or truncated, in which the tangential arrival of the air to be dusted takes place, - a sedimentation chamber, funnel-shaped or cylindrical, arranged under the upper body; this chamber being equipped with means for recovering waste at its lower part, - a filter cartridge consisting of vertical filter sleeves which extend between said sedimentation chamber and a cover where the filtered air is evacuated.

[0008] The corresponding filter sleeves have a generally cylindrical shape and are conventionally made of needle felt type material, or any other resistant material allowing equivalent filtration.

[0009] Document FR2856936 teaches in a known manner that these sleeves are stretched vertically within the filter cartridge between two suitable support structures: - their lower ends are secured to a lower support structure, for example in the form of a grid, which is located above the sedimentation chamber, and which allows access of stale air to the outer side of the filter sleeves; - their upper ends are secured to an upper support structure, generally in the form of a tray with circular openings, to allow the evacuation of filtered air.

[0010] The assembly of each filter sleeve within this type of device consists first of all in securing their upper end at one of the openings of the upper plate. This securing is traditionally obtained by means of an integrated member in the form of a deformable ring (commonly called in the trade "snap ring") in the filter sleeve.

[0011] The lower end of the sleeve is then fixed to the lower support structure.

[0012] For this, the corresponding end is provided with a bottom plate provided with a projecting rod, which projecting rod is intended to pass through a complementary orifice provided in a profile constituting the lower support structure.

[0013] In a known manner, the projecting rod in question comprises a thread which cooperates with a nut to ensure that the sleeve is held in position; the adequate tensioning of each sleeve is obtained by an appropriate tightening operation of this nut.

[0014] Due to an environment which may contain dust or explosive waste, the constituent elements of the lower support structure and the projecting rod are made of materials which do not allow the formation of sparks in the event of impacts or friction.

[0015] However, due to the current structure of filtration devices, an operator must access the lower support structure to perform most of the assembly and maintenance operations relating to the filter sleeves.

[0016] However, the corresponding interventions are not very practical to carry out because of the narrow spaces between the sleeves.

[0017] Furthermore, these interventions are carried out in dusty and dirty environments; they can be dangerous for the operator due to the dust present, some of which can present health risks, particularly in the context of equipment dealing with atmospheres which may in certain cases have explosive or flammable characteristics.

[0018] This is why document FR2856936 proposes as a solution responding to these problems of the prior art an air filtration device of the filter bag type described in document FR2856936, additionally comprising a filter cartridge consisting of filter bags stretched vertically, with top and bottom fixing means for the filter bags adapted to allow adjustment of the tension of each bag at their upper end. This allows an operator to consequently carry out most of the assembly and maintenance operations at the upper support structure of the bags, in a safe and low-polluted environment.

[0019] Document FR2856936 teaches more precisely a deformable ring with an external and peripheral annular groove, this ring being intended to be positioned within the sleeves in the upper part, once the sleeves are fixed on the lower support structure, and stretched, so as to maintain said sleeves in this stretched state by tightening against the contour of the openings of the upper support structure.

[0020] Document FR2856936 teaches that the lower end of the filter sleeves is provided with a bottom cup, fitted with a projecting rod comprising a hooking element. This hooking element is intended to cooperate with a support profile of suitable conformation, arranged at the level of the lower support structure in the form of folded sheet metal. This profile consists of a central part extending vertically, and the upper end of which is extended by a return element at right angles or substantially at right angles extending over its entire length, and provided with several open slots each ensuring the passage of a projecting rod of the sleeve and the positioning of the hooking element of said projecting rod.

[0021] The upper end of the support profile(s) comprises a return element consisting of two parts forming a dihedral, one part extending at right angles or substantially at right angles from the upper end of the central part of the support profile, the other part extending diagonally downwards.

[0022] Document FR2856936 also teaches a means for pulling the upper end of a filter sleeve in the form of a hand tool, and a means for operating said pulling means.

[0023] Document FR2856936 also teaches a particular method of mounting a filter sleeve within an air filtration device which consists mainly and successively of: - to fix the lower end of the filter sleeve, by a suitable fixing means, to the lower support structure, - to tension the filter sleeve by a vertical, regular and constant traction, in particular between thirty (30) and forty (40) kilograms, i.e. a traction force between two hundred and ninety-four (294) Newtons and three hundred and ninety-two (392) Newton, - to fix the upper end of the filter sleeve to the upper support structure using a suitable fixing means.

[0024] The operation of attaching the sleeves has the advantage of being able to be carried out from the upper area of ​​the cartridge, at the level of the cap.

[0025] To do this, the operator holds the upper end of the sleeve and swings this sleeve slightly so as to position the attachment element in one of the slots. The lower end of the sleeves is thus fixed to the lower support structure from above without requiring any special tools.

[0026] This solution, however, has the disadvantage of being imprecise, as the swinging attachment can be hazardous and tedious in the case of a large number of filter sleeves.

[0027] Furthermore, the successive tensioning of the sleeves with a manual tool is a repetitive and manual task, and requires significant physical effort.

[0028] Tensioning a sleeve is done by a manual tensioning tool which is installed at a filter sleeve to tension said sleeve. The tool is then uninstalled and then moved to another sleeve and so on.

[0029] The tension exerted on each sleeve may differ according to the operator's judgment and thus differ greatly from a target tension value.

[0030] Furthermore, the successive tensioning of the sleeves can cause mechanical deformations of the supports, as the sleeves are tensioned.

[0031] In the case of a tension applied to each filter sleeve of between thirty (30) and forty (40) kilograms, i.e. a tensile force of between two hundred and ninety-four (294) Newton and three hundred and ninety-two (392) Newton, in a filter cartridge comprising forty (40) sleeves, this represents a total tension exerted on the supports of between one thousand two hundred (1200) and one thousand six hundred (1600) kilograms, i.e. a force exerted between eleven thousand seven hundred and twenty (11720) Newton and fifteen thousand six hundred and eighty (15680) Newton. These approximate values ​​are calculated by considering the unit "g" of Earth's gravity as equal to 9.8 m / s2.

[0032] It should be noted that there are filter cartridges comprising more than three hundred and fifty (350) filter sleeves, which generates significant tension on the supports, between ten (10) and fourteen (14) tons, i.e. an exerted force of between one hundred thousand (100,000) and one hundred and thirty-seven thousand (137,000) Newtons.

[0033] Thus, it is necessary to check, once all the sleeves have been calibrated successively, the tensions of the first sleeves put under tension, and readjust them, which increases the handling. In fact, the tensioning operation must be carried out several times times so that all the sleeves are stretched satisfactorily.

[0034] Excessive disparity in voltage applied to the different sleeves of the device causes problems, including: - faster core clogging of the sleeves in the event of overvoltage, which increases the pressure losses of the device, and increases the energy consumption of the ventilation systems associated with the device, - premature wear of the handles weakening them and increasing the risk of them tearing in the event of overvoltage, - random sleeve tension, making the cleaning of all the sleeves irregular. It is then necessary to increase the frequency of cleaning to limit pressure losses, which increases compressed air consumption.

[0035] Another problem with this device is that the sleeves gradually stretch and relax during their life cycles and during normal use. This reduces the filtration efficiency of the device.

[0036] To remedy this, a regular maintenance operation is necessary so that an operator can come and re-tighten all of the filter sleeves.

[0037] This operation being expensive, few manufacturers carry it out, which harms the consumption of the airflow part and the compressed air unclogging system.

[0038] The present invention aims to remedy these drawbacks by proposing an air filtration device with filter sleeves making it possible to facilitate operations of mounting and maintenance of filter sleeves in said device for intervention personnel.

[0039] Another objective of the invention is to propose a device whose maintenance is facilitated by limiting interventions in the dangerous lower zone of the device.

[0040] Another objective is to propose an economical and secure device, comprising means for tensioning the filter sleeves allowing the filter sleeves to be tensioned in a simplified, precise and rapid manner.

[0041] Another objective is to propose a device capable of compensating for variations in the length of the sleeves due to their production or due to progressive elongation over time.

[0042] Another objective is to propose a method for mounting and maintaining filter sleeves in an air filtration device with filter sleeves.

[0043] To this end, the invention relates to an air filtration device with filter sleeves comprising - an upper body from which the air filtered by the device is evacuated, - a sedimentation chamber, in particular in the shape of a funnel or cylindrical, arranged under said upper body, and provided with means for recovering waste at its lower part, - a vertical filter cartridge comprising a casing, in particular a peripheral cylindrical casing, and at least two filter sleeves extending into the casing, in particular a peripheral cylindrical casing, between said sedimentation chamber and a cover of the upper body, said sleeves being attached substantially vertically within the filter cartridge, on the one hand to a lower support structure by hooking members of the lower ends of the sleeves, and on the other hand to an upper support structure in the form of a tray with openings, in particular circular openings, by assembly members of the upper ends of the sleeves.

[0044] Advantageously, the device comprises means for energizing all of the filter sleeves to a determined average voltage.

[0045] This simplifies the tensioning of the filter bags. By vertically separating the lower and upper support structures from each other, this allows all the bags to be stretched simultaneously and this allows them to be subjected to the same determined average tension. Tensioning all the bags together and maintaining them together saves time and limits the possibility of portions of the lower or upper support structures deforming locally and affecting the adjustment of the bag tensions. The device thus obtained makes it easier to assemble all the bags and tension them.

[0046] Document FR2856936 does not teach a solution allowing simultaneous tensioning of all the filter bags and maintaining tension. Nor does it teach a solution allowing simplified maintenance by simultaneously adjusting the tension of all the bags in a single operation.

[0047] This device makes it possible to precisely define the distance between the two support structures. By knowing the length of the sleeves and their stretch coefficient, it is in fact possible to calculate the tension applied to each sleeve precisely.

[0048] According to a characteristic of the invention, the device comprises means for tensioning the assembly of at least two filter sleeves in the form of means for translating the lower support structure relative to the upper support structure, said upper support structure being fixedly mounted relative to the upper body. Once tensioned, these translation means make it possible to keep the sleeves tensioned.

[0049] This allows the upper support structure to remain fixed, only the lower support structure moves within the filter cartridge, which reduces the number of moving parts and simplifies the design of the device.

[0050] According to a characteristic of the invention, the translation means are in the form of at least one threaded rod of the lower support structure cooperating with at least one corresponding tapped hole of a part of the upper support structure, or vice versa.

[0051] This ensures high translation precision and limits dangerous sparks in such an explosive environment.

[0052] According to a characteristic of the invention, the lower support structure comprises translational guide means cooperating with an internal vertical wall of the envelope, in particular a peripheral cylindrical wall, these guide means being in the form in particular of rollers pivoting freely vertically against said wall.

[0053] This makes it possible to limit the movements of the lower support structure other than in translation, which limits shocks and sparks during its movement and during its use.

[0054] According to a characteristic of the invention, the device comprises individual means for maintaining a voltage of each filter sleeve within a defined voltage interval.

[0055] This makes it possible to compensate for variations in tension due to small differences which may exist in the length of the sleeves, and which are due to manufacturing defects, for example in sewing. It is thus possible to obtain sleeves fitted in the device which have a tension included in the same defined tension interval.

[0056] Document FR2856936 does not teach a solution to compensate for a possible elongation of a single filter sleeve, which causes a reduction in the harmful tension exerted on this sleeve. It teaches manipulation on each sleeve by an operator with a tension device which must be moved from one sleeve to another, and presenting the problems described above.

[0057] In fact, the combination of means for tensioning all the filter sleeves and the individual means for maintaining tension within a defined tension interval makes it possible to ensure rapid tensioning of the sleeves while ensuring uniformity of the tensions of each sleeve.

[0058] When the sleeves relax, the average tension of all the sleeves decreases, but the holding means make it possible to maintain the tension of each sleeve within a satisfactory range. Maintenance is also simplified, since it is sufficient to actuate the tensioning means to bring the average tension of all the sleeves back to a determined average tension, in particular between thirty (30) and forty (40) kilograms, i.e. a tensile force between two hundred and ninety-four (294) Newtons and three hundred and ninety-two (392) Newtons.

[0059] According to a characteristic of the invention, the individual means for maintaining a tension in a defined tension interval of each filter sleeve comprise an elastic return member at the lower end of each filter sleeve, configured to ensure a tension of said sleeve included in a tension interval of defined tension.

[0060] According to a characteristic of the invention, the hooking members of the filter sleeves comprise a rod projecting from the filter sleeve with a hooking element, said hooking element being intended to cooperate with an open slot of a suitable folded sheet metal profile of the lower support structure.

[0061] This allows the lower end of each sleeve to be quickly assembled to the lower support structure.

[0062] As taught in document FR2856936, the lower end of each filter sleeve may be provided with a hooking element comprising a bottom cup, provided with a projecting rod comprising a hooking element; this hooking element being intended to cooperate with a support profile of suitable conformation, arranged at the level of the lower support structure.

[0063] This attachment element may consist of a chamfered ring configured to come into contact with the profile bearing on a spiral spring forming said elastic return member, itself bearing against a lock nut screwed onto a thread provided on the end of the rod.

[0064] The lower support structure may comprise at least one support profile, in the form of folded sheet metal, consisting of a central part extending vertically, and the upper end of which is extended by a return element at right angles or substantially at right angles, extending over its entire length. The corresponding return element may be provided with several open slots, each ensuring the passage of a rod projecting from the sleeve and the positioning of the element for attaching said projecting rod. The upper end of the support profile(s) may comprise a return element consisting of two parts forming a dihedral. One of said parts, called the horizontal part, may extend at right angles or substantially at right angles from the upper end of the central part of the support profile; the other of said parts, called the inclined part, extending diagonally downwards.This return element may be provided with a plurality of open slots, each of which ensures the passage of a rod projecting from the sleeve, the attachment element of said projecting rod being intended to be positioned under the aforementioned horizontal part.

[0065] This makes it possible to simplify the assembly of the filter sleeves to the lower support structure.

[0066] The invention relates to a method for mounting and tensioning at least two filter sleeves within an air filtration device as described above, said method comprising the following steps: - fixing the upper ends of at least two filter sleeves to an upper support structure by suitable assembly members, - fixing the lower ends of said at least two filter sleeves, by suitable individual hooking members, on a lower support structure, - simultaneous tensioning of said at least two filter sleeves by means of tensioning all the filter sleeves exerting on each sleeve a determined average tension, in particular between thirty (30) and forty (40) kilograms, i.e. a tensile force between two hundred and ninety-four (294) Newton and three hundred and ninety-two (392) Newton.

[0067] Document FR2856936 does not teach simultaneous tensioning of all the filter sleeves. Nor does it teach a solution allowing simplified maintenance by simultaneously adjusting the tension of all the sleeves of the device in a single operation.

[0068] It should be noted that the assembly steps according to the invention differ from the teachings of document FR2856936, this method according to the invention making it possible to simplify the number of manipulations for assembly and maintenance of at least two filter sleeves in such a device.

[0069] For maintenance, it is simply sufficient to implement the last step of this described process by simultaneously tensioning all of the sleeves until a determined average tension is reached on each sleeve.

[0070] The invention relates to a filter sleeve comprising a hooking member at its lower end and an assembly member at its upper end configured to allow attachment of said sleeve in a filter cartridge of a device as described previously.

[0071] The invention relates to a filtering installation comprising at least one such device as described above.

[0072] Other aims and advantages of the present invention will appear during the description which follows with reference to the attached drawings illustrating an exemplary embodiment and in which:

[0073] [Fig.l] is a schematic perspective view with semi-transparent walls of an air filtration device with filter sleeves according to the invention.

[0074] [Fig.2] is a partial schematic view of a filter cartridge of the device of [Fig.l], of which a portion of a peripheral wall is missing, revealing filter sleeves extending between an upper support structure and a lower support structure.

[0075] [Fig.3] is a schematic side view of the filter cartridge of the device of the [Fig.2],

[0076] [Fig.4] is a detail view of an upper part of the device of [Fig.2].

[0077] [Fig.5] is a detail view of the lower end of a filter sleeve and a part of the lower support structure of the device of [Fig.2].

[0078] [Fig.6] is a schematic sectional detail view of the upper end of a filter sleeve and part of the upper support structure of the device of [Fig.2],

[0079] The invention relates to an air filtration device with filter sleeves 1 hereinafter referred to as "device 1" or "air filtration device 1". It comprises, in a known manner, an upper body 2 with an outlet opening 20 from which the air filtered by the device 1 is evacuated. The upper body 2 is surmounted by a cap 21.

[0080] The device 1 also comprises a sedimentation chamber 3 here in the form of a funnel or cylindrical, with vertical walls, arranged under said upper body 2, and provided with means for recovering waste at its lower part.

[0081] The device 1 also comprises a filter cartridge 4, vertical, comprising a peripheral cylindrical casing 40 here and filter sleeves 5, at least two, extending into the peripheral cylindrical casing 40, interposed between said sedimentation chamber 3 and the cap 21 of the upper body 2.

[0082] These filter sleeves 5, hereinafter referred to as "sleeves 5", are attached substantially vertically within the filter cartridge 4 on the one hand to a lower support structure 6 and on the other hand to an upper support structure 7 in the form of a plate 70 with circular openings 71 here. The upper support structure 7 may comprise at least one reinforcing frame 72 making it possible to stiffen the plate 70, as illustrated in [Fig.l].

[0083] The handles 5 are substantially vertical, that is, they may be carried by a vertical axis, or have an angle of inclination relative to a vertical axis of less than five (5) degrees. As illustrated in [Fig. 3], the handles may have an angle of inclination relative to a vertical axis of three (3) degrees, plus or minus two (2) degrees, in order to facilitate the installation and positioning of the handles 5.

[0084] With reference to [Fig.l], the device 1 is considered in a position of use, with the sedimentation chamber 3 placed and resting on the ground and the upper body 2 above.

[0085] Thus, as illustrated in the figures, the bottom of the device 1 is at the bottom of the figures, and the top of the device 1 is at the top of the figures.

[0086] The device 1 further comprises means 8 for tensioning all of the filter sleeves 5 to a determined average tension, in particular between thirty (30) and forty (40) kilograms, i.e. a tensile force between two hundred and ninety-four (294) Newtons and three hundred and ninety-two (392) Newtons.

[0087] These tensioning means 8 are in the form of translation means 80 of the lower support structure 6 relative to the upper support structure 7. The upper support structure 7 is mounted in the device 1 fixedly relative to the upper body 2 by welding, riveting, bolting or any other means allowing fixed mounting. This mounting may or may not be reversible.

[0088] As illustrated in the figures, the translation means 80 may be in the form of three threaded rods 81 of the lower support structure 6, regularly spaced and cooperating with tapped holes in parts 82 of the upper support structure 7, or vice versa.

[0089] Each threaded rod 81 can be mounted on the one hand free to rotate with the lower support structure 6, and on the other hand protruding from the upper support structure 7 and having at its upper end a nut 83 fixedly secured to said threaded rod 81, as illustrated in [Fig.4].

[0090] This makes it possible to operate the means 8 for energizing all of the filter sleeves 5 from above the plate 70, which is a less dangerous and dusty area for the intervention personnel.

[0091] Thus, rotating a nut 83 makes it possible to rotate the corresponding threaded rod 81. The device 1 may comprise drive means, such as, for example, shafts of electric stepper motors, removable or not, comprising end pieces configured to rotate the nuts 83 simultaneously or not. It is thus possible to translate the lower support structure 6 relative to the upper support structure by screwing or unscrewing the nuts 83. It is also possible to adjust the inclination of the lower support structure 6 by acting on some of the nuts 83.

[0092] According to an embodiment not illustrated here, the device 1 may comprise means for controlling the horizontality of the lower support structure 6, for example in the form of spirit levels inserted between the threaded rods 81.

[0093] According to an embodiment not illustrated here, the device 1 may comprise means for controlling the rotation of each threaded rod 81 remotely, in the form of a human-machine interface controlling an electric stepper motor connected to each threaded rod 81. The device 1 may also comprise means for measuring the translation height of the lower support structure 6 in the form, for example, of a displacement sensor on said stepper motor.

[0094] It is thus possible to tension all of the filter sleeves 5 remotely in complete safety, without having to enter the device 1, and to calculate the overall tension exerted on all of the sleeves to deduce an average tension exerted on each sleeve 5.

[0095] The lower support structure 6 may comprise translational guide means 60 cooperating with an internal vertical wall 41 of the peripheral cylindrical envelope 40. These translational guide means may be presented, as illustrated in FIGS. 2 and 3, in the form of three rollers 600 spaced regularly apart. lately on the periphery of the lower support structure 6, mounted free to rotate vertically relative to said lower support structure 6. These rollers 600 can come to bear against the vertical wall 41 of the interior of the peripheral cylindrical casing 40.

[0096] Each handle 5 has a lower end 50 and an upper end 51. The lower end 50 of each handle has a hooking member 52 capable of allowing it to be hooked to the lower support structure 6, and an assembly member 53 capable of allowing it to be assembled to the upper support structure 7.

[0097] The hooking member 52 will be described later.

[0098] The assembly member 53 may, in a known manner, be in the form of a deformable ring secured to the upper end 51 of the sleeve 5, and it may comprise an annular groove extending over its external contour, intended to fit onto the internal contour of the circular openings 71 of the upper support structure 7, so as to block the corresponding sleeve 5 in a corresponding circular opening 71.

[0099] This deformable ring may have an upper part having a collar with a diameter greater than the diameter of the circular openings 71, so as to prevent the corresponding sleeve 5 from accidentally falling entirely through a circular opening 71.

[0100] The device 1 may comprise individual means 54 for maintaining a voltage within a defined voltage interval of each filter sleeve 5. The defined voltage interval is substantially plus or minus five (5) kilograms of voltage, i.e. a voltage interval of plus or minus forty-nine (49) Newtons relative to the value of the determined average voltage, which is in particular between thirty (30) and forty (40) kilograms, i.e. between two hundred and ninety-four (294) Newtons and three hundred and ninety-two (392) Newtons.

[0101] Said individual means 54 for maintaining a tension in a defined tension interval of each filter sleeve 5 may comprise an elastic return member 55, located at the lower end 50 of each sleeve 5, said elastic return member 55 being configured to ensure a tension of said sleeve 5 included in the tension interval defined above.

[0102] The hooking member 52 of each sleeve 5 allowing it to be attached to the lower support structure 6 may comprise a projecting rod 520 of the filter sleeve with a hooking element 521, said hooking element 521 being intended to cooperate with an open slot 61 of a profile 62 made of folded sheet metal adapted from the lower support structure 6.

[0103] As illustrated in [Fig.5], this attachment element 521 can be in the form: - a chamfered ring 522 configured to come into contact with the profile, - a spiral spring, forming said elastic return member 55, bearing against the underside of the chamfered ring 522, - a lock nut 523 screwed onto a free end of the projecting rod 520, the spring bearing against this lock nut 523. This lock nut 523 may be blind.

[0104] The spiral spring forming said elastic return member 55 is thus interposed between the chamfered ring 522 and the lock nut 523.

[0105] More generally, any type of particular equivalent hooking member can be envisaged, comprising the individual means 54 for maintaining a tension in a defined tension interval of each filter sleeve 5.

[0106] Concerning the lower support structure 6, it can be made up of a plurality of parallel folded sheet metal profiles 62 fixed to a reinforcement arranged at a lower end of the peripheral cylindrical envelope 40, the fixing in question being able to be carried out by means of connecting plates.

[0107] The profiles may consist of a vertical central portion delimited by an upper end edge and a lower end edge. The lower end edge may be extended over its entire length by a right-angle return element, to improve the rigidity of the profiles 62.

[0108] The upper end edge of each profile 62 may be provided with a return element, in the form of a dihedron, consisting of a first and a second part. The first part may extend at right angles, along a horizontal or substantially horizontal plane. The second part may extend in a downwardly inclined manner.

[0109] The return element may have several open slots 61, extending transversely over the two parts of said upper return element. The end of each open slot 61 may have a general V-shape at the opening. The other end of each open slot may extend only partially over the first horizontal part of the return element.

[0110] When mounting a sleeve 5 in a cartridge 4, the lower end 50 and the hooking member 52 of the sleeve 5 can be passed and hung through a corresponding circular opening 71 of the plate 70.

[0111] The distance between the lower support structure 6 and the upper support structure can be configured to be a few millimeters to a few centimeters less than the length of the filter sleeves 5.

[0112] The assembly member 53 of the sleeve 5 is then fixed to the corresponding circular opening 71 as illustrated in [Fig.6].

[0113] The sleeve is slightly stretched and the projecting rod 520 of the sleeve 5 is positioned at the flared end of the open slot 61 concerned, the chamfered ring 522 being arranged under the end of the second part of the element of return by compressing the spiral spring. The V-shape of this end 33 facilitates the insertion of the projecting rod 520 into the corresponding open slot 61

[0114] It is then sufficient to push the projecting rod 520 into the open slot 61 to finalize the positioning. Indeed, the inclined conformation of the second part of the return element allows the hooking member 52 to move until it comes into position against the lower face of the first horizontal part of the return element. The first inclined part of the upper return element forms a sort of stop, intended to hold the hooking member 52 in position against the first horizontal part of the return element, when the sleeve 6 is kept taut.

[0115] To deactivate the attachment of the hooking member 52 to the lower support structure 6, it is sufficient to remove the tension exerted on the sleeve 5 and to disengage the projecting rod 520 from the open slot 61, or alternatively to pull the chamfered ring downwards to allow disengagement of the projecting rod 520 from the open slot 61.

[0116] The elastic return member 55 and more particularly the spiral spring may be a spring known as a constant force (return) spring or a spring known as a constant tension (return) spring.

[0117] The invention also relates to a method of mounting and tensioning at least two filter sleeves within an air filtration device 1 as described above.

[0118] This method comprises the following steps: - fixing the upper ends 51 of at least two filter sleeves 5 on an upper support structure 7 by suitable assembly members 53, - fixing the lower ends 50 of said at least two filter sleeves 5, by suitable individual hooking members 52, on a lower support structure 6, - simultaneous tensioning of said at least two filter sleeves 5 by tensioning means 8 of all the filter sleeves 5 exerting on each sleeve 5 a determined average tension, in particular between thirty (30) and forty (40) kilograms, i.e. a tensile force between two hundred and ninety-four (294) Newtons and three hundred and ninety-two (392) Newtons.

[0119] It should be noted that the fixing of the filter sleeves 5 in the filter cartridge 4 can be done on a manufacturing site of the filter cartridge 4, which is then transported to its place of use or installation. Once installed, it is possible to implement the tensioning means 8 to simultaneously tension all of the filter sleeves 5 to a determined average tension.

[0120] The device 1 may comprise means for measuring or detecting the voltage exerted by the means 8 for energizing all of the filter sleeves. 5, for example in the form of traction sensors on each of the translation means 80.

[0121] The device may further comprise means for controlling the individual means 54 for maintaining a tension in a defined tension interval of each filter sleeve, for example in the form of detectors of the compression of the spiral spring of each sleeve 5.

[0122] The invention further relates to at least one filter sleeve 5 configured to allow attachment of said sleeve 5 in a filter cartridge 4 of a device 1 as described previously.

[0123] This at least one filter sleeve 5 comprises, as indicated above, a hooking member 52 at its lower end 50 and an assembly member 53 at its upper end 51, allowing it to be mounted in the filter cartridge 4 of the device 1.

[0124] At least one device 1 as described above can be included in an installation making it possible to capture pollutants and then filter and recover them.

Claims

Claims

1. Air filtration device (1) with filter sleeves comprising - an upper body (2) from which the air filtered by the device (1) is evacuated, - a sedimentation chamber (3), in particular funnel-shaped or cylindrical, arranged under said upper body (2), and provided with means for recovering waste at its lower part, - a vertical filter cartridge (4) comprising a peripheral, in particular cylindrical, casing (40) and at least two filter sleeves (5) extending in the peripheral, in particular cylindrical casing (40) between said sedimentation chamber (3) and a cap (21) of the upper body (2), said sleeves (5) being attached vertically within the filter cartridge (4), on the one hand to a lower support structure (6) by hooking members (52) of the lower ends of the sleeves (50),and on the other hand to an upper support structure (7) in the form of a plate (70) with openings, in particular circular ones (71) by assembly members (53) of the upper ends of the sleeves (51), characterized in that the device (1) comprises means for tensioning (8) all of the filter sleeves (5) to a determined average tension.,

2. Air filtration device (1) according to claim 1, characterized in that it comprises means for tensioning (8) the set of filter sleeves (5) in the form of translation means (80) of the lower support structure (6) relative to the upper support structure (7), said upper support structure (7) being fixedly mounted relative to the upper body (2).

3. Air filtration device (1) according to claim 2, characterized in that the translation means (80) are in the form of at least one threaded rod (81) of the lower support structure (6) cooperating with at least one corresponding tapped hole of a part (82) of the upper support structure, or vice versa.

4. Air filtration device (1) according to one of claims 1 to 3, characterized in that the lower support structure (6) comprises translational guide means (60) cooperating with a vertical inner wall (41) of the envelope, in particular a peripheral cylindrical envelope (40), in the form in particular of rollers (600) pivoting freely vertically against said wall (41).

5. Air filtration device (1) according to one of claims 1 to 4, characterized in that it comprises individual means (54) for maintaining a voltage in a defined voltage interval of each filter sleeve (5).

6. Air filtration device (1) according to claim 5, characterized in that the individual means (54) for maintaining a tension within a defined tension interval of each filter sleeve (5) comprise an elastic return member (55) at the lower end (50) of each filter sleeve (5) configured to ensure a tension of said sleeve (5) within a defined tension interval.

7. Air filtration device (1) according to one of claims 1 to 6, characterized in that the hooking members (52) of the at least two filter sleeves (5) comprise a projecting rod (520) of the filter sleeve (5) with a hooking element (521), said hooking element (521) being intended to cooperate with an open slot (61) of a folded sheet metal profile (62) adapted from the lower support structure (6).

8. Method for mounting and tensioning at least two filter sleeves (5) within an air filtration device (1) according to one of claims 1 to 7, said method comprising the following steps: - fixing the upper ends (51) of at least two filter sleeves (5) on an upper support structure (7) by suitable assembly members (53), - fixing the lower ends (50) of said at least two filter sleeves (5), by suitable individual hooking members (52), on a lower support structure (6), - simultaneously tensioning said at least two filter sleeves (5) by tensioning means (8) of all the filter sleeves (5) exerting on each sleeve (5) a determined average tension.

9. Filter sleeve (5) characterized in that it comprises a hooking member (52) at its lower end (50) and an assembly member (53) at its upper end (51) configured to allow attachment of said sleeve (5) in a filter cartridge (4) of a device (1) according to one of claims 1 to 7.

10. Filtering installation comprising at least one air filtration device (1) with filter sleeves (5) according to one of claims 1 to 7.

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