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 also relates to a filter sleeve adapted to such a device, and an installation comprising such a device.

[0004] The term "bag-type air filtration device" refers, in particular, to a cyclonic pre-separation dust collector for filtering air streams necessary for transporting pollutants. This dust collector can be integrated into a system that allows for the direct capture of said pollutants at the source, followed by filtration and recovery. Such a dust collector has been commercially available for years under the trade name "Cyclofiltre®".

[0005] Such an air filtration device of the type with filter bags of this kind 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, processing or storage of powdered products, or from certain industries resulting in the emission of waste, such as sawdust or very volatile shavings.

[0007] This type of device described in document FR2856936 consists in a known manner of three main elements generally centered on the same vertical axis: - an upper body, cylindrical or truncated cone, into which the air to be dusted enters tangentially, - a sedimentation chamber, funnel-shaped or cylindrical, located under the upper body; this chamber being equipped with means for collecting waste at its lower part, - a filter cartridge consisting of vertical filter sleeves which extend between said sedimentation chamber and a cap into which the filtered air is discharged.

[0008] The corresponding filter sleeves have a general cylindrical shape and are classically made of needle-punched felt material, or any other resistant material allowing equivalent filtration.

[0009] Document FR2856936 teaches in a known way 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 the foul air on the outside side of the filter sleeves; - their upper ends are secured to an upper support structure, usually in the form of a tray with circular openings, to allow the filtered air to escape.

[0010] The assembly of each filter sleeve within this type of device consists first of all in securing its upper end to one of the openings of the upper plate. This securing is traditionally achieved by means of an integrated, deformable ring-shaped element (commonly called a "snap ring" in the trade) within the filter sleeve.

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

[0012] For this purpose, the corresponding end is provided with a base plate having a protruding rod, which protruding rod is intended to pass through an additional orifice provided in a profile constituting the lower support structure.

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

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

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

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

[0017] Moreover, 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 may present health risks, particularly in the context of equipment dealing with atmospheres which may in some cases have explosive or flammable characteristics.

[0018] Therefore, document FR2856936 proposes, as a solution to these prior art problems, a bag-type air filtration device The filtering system described in document FR2856936 additionally comprises a filter cartridge made up of vertically tensioned filter sleeves, with upper and lower fixing means for the filter sleeves adapted to allow tension adjustment of each sleeve at its upper end. This enables an operator to perform most assembly and maintenance operations on the upper support structure of the sleeves in a safe and relatively clean environment.

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

[0020] Document FR2856936 states that the lower end of the filter sleeves is fitted with a bottom cup, equipped with a protruding rod having a hooking element. This hooking element is designed to cooperate with a support profile of suitable shape, provided in the lower support structure in the form of folded sheet metal. This profile consists of a central part extending vertically, the upper end of which is extended by a right-angled or substantially right-angled return element extending along its entire length, and provided with several open slots, each ensuring the passage of a protruding sleeve rod and the positioning of the hooking element of said protruding rod.

[0021] The upper end of the support profile(s) includes a return element consisting of two parts forming a dihedral angle, one part extending at a right angle or substantially at a right angle 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 of pulling the upper end of a filter sleeve in the form of a hand tool, and a means of operating said pulling means.

[0023] Document FR2856936 also teaches a particular method for 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 means of a suitable fastening, to the lower support structure, - to put the filter sleeve under tension by a vertical, regular and constant traction, in particular between thirty (30) and forty (40) kilograms, i.e. a traction force between two hundred ninety-four (294) Newtons and three hundred ninety-two (392) Newtons, - to fix the upper end of the filter sleeve to the upper support structure by means of a suitable fixing device.

[0024] The sleeve attachment operation 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 gently rocks it to position the fastening element in one of the slots. The lower end of the sleeves is thus attached to the lower support structure from above without requiring any special tools.

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

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

[0028] Tensioning a sleeve is achieved using a manual tensioning tool installed on a filter sleeve to tension said sleeve. The tool is then removed and moved to another sleeve, and so on.

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

[0030] In addition, 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 ninety-four (294) Newtons and three hundred ninety-two (392) Newtons, 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 twenty (11720) Newtons and fifteen thousand six hundred eighty (15680) Newtons. These approximate values ​​are calculated 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 with more than three hundred and fifty (350) filter sleeves, which generates a significant tension on the supports, between ten (10) and fourteen (14) tonnes, i.e., a force exerted 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 successively calibrated, the tension 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 for all the sleeves to be satisfactorily tensioned.

[0034] Excessive disparity in the voltage applied to the different sleeves of the device causes problems, including: - faster clogging of the sleeves in case of overvoltage, which increases the pressure drop of the device and increases the energy consumption of the ventilation systems associated with the device, - Premature wear of the sleeves weakens them and increases the risk of them tearing in the event of overstressing, - Uneven tension in the hoses, resulting in inconsistent cleaning of all hoses. This necessitates increasing the cleaning frequency to limit pressure losses, which in turn increases compressed air consumption.

[0035] Another problem with this device is that the sleeves gradually lengthen and loosen during their lifespan and under normal use. This reduces the filtration efficiency of the device.

[0036] To remedy this, a regular maintenance operation is necessary for an operator to come and tighten all the filter sleeves.

[0037] Since this operation is costly, few manufacturers carry it out, which is detrimental to the consumption of the air handling unit and the compressed air cleaning system.

[0038] The present invention aims to remedy these drawbacks by proposing an air filtration device with filter bags that facilitates the assembly and maintenance of filter bags in said device for intervention personnel.

[0039] Another objective of the invention is to provide a device whose maintenance is facilitated by limiting interventions in the lower dangerous area 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 sleeve length due to their production or due to progressive elongation over time.

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

[0043] To this end, the invention relates to an air filtration device with filter bags comprising - a superior body from which the air filtered by the device is expelled, - a sedimentation chamber, in particular funnel-shaped or cylindrical, arranged under said upper body, and equipped with means for collecting waste at its lower part, - a vertical filter cartridge comprising a peripheral cylindrical casing and at least two filter sleeves extending in the peripheral cylindrical casing between said sedimentation chamber and a cap 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 elements of the lower ends of the sleeves, and on the other hand to an upper support structure in the form of a tray with circular openings by assembly elements of the upper ends of the sleeves.

[0044] Advantageously, the device includes means for energizing all the filter sleeves at a determined average voltage.

[0045] This simplifies the tensioning of the filter sleeves. By vertically separating the lower and upper support structures, all the sleeves can be stretched simultaneously and subjected to the same predetermined average tension. Tensioning and maintaining all the sleeves together saves time and prevents local deformation of portions of the lower or upper support structures, which could affect the tension settings of the sleeves. The resulting device facilitates the assembly and tensioning of all the sleeves.

[0046] Document FR2856936 does not teach a solution for simultaneously tensioning and maintaining tension on all filter bags. Nor does it teach a solution for simplified maintenance by simultaneously adjusting the tension of all 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 elongation coefficient, it is indeed possible to calculate the tension applied to each sleeve precisely.

[0048] According to one feature of the invention, the device comprises means for energizing all 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 energized, these translation means allow the sleeves to be kept under tension.

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

[0050] According to one feature 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 translational accuracy and limits dangerous sparks in such an explosive environment.

[0052] According to a feature of the invention, the lower support structure comprises translational guidance means cooperating with an internal vertical wall of the envelope, in particular a peripheral cylindrical wall, these guidance means being in the form 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 one feature of the invention, the device includes individual means for maintaining a voltage of each filter sleeve within a defined voltage range.

[0055] This makes it possible to compensate for variations in tension due to small differences that may exist in sleeve length, and which are due to manufacturing defects, for example, in the stitching. It is thus possible to obtain sleeves mounted in the device that have a tension within the same defined tension range.

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

[0057] In fact, the combination of means for energizing all the filter sleeves and the means for maintaining individual energization within a defined voltage range makes it possible to ensure rapid energizing of the sleeves while ensuring homogeneity 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 activate the tensioning means to bring the average tension of all the sleeves back to a predetermined average tension, in particular between thirty (30) and forty (40) kilograms, i.e., a tensile force between two hundred ninety-four (294) Newtons and three hundred ninety-two (392) Newtons.

[0059] According to one feature of the invention, the individual means for maintaining a voltage within a defined voltage range of each filter sleeve comprise an elastic return element at the lower end of each filter sleeve, configured to ensure a tension of said sleeve within a defined tension range.

[0060] According to one feature of the invention, the hooking members of the filter sleeves comprise a protruding rod of the filter sleeve with a hooking element, said hooking element being intended to cooperate with an open slot of a bent sheet metal profile adapted from 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 can be provided with a hooking element comprising a bottom cup, equipped with a protruding rod comprising a hooking element; this hooking element being intended to cooperate with a support profile of suitable shape, 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 supported by a spiral spring forming said elastic return element, itself supported against a lock nut screwed onto a thread provided on the end of the rod.

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

[0065] This simplifies 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 using suitable assembly components, - fixing the lower ends of said at least two filter sleeves, by appropriate individual hooking devices, 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 ninety-four (294) Newtons and three hundred ninety-two (392) Newtons.

[0067] Document FR2856936 does not teach simultaneous energizing of all filter sleeves. Nor does it teach a solution enabling simplified maintenance by simultaneously adjusting the tension of all the device's sleeves 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 an assembly and maintenance of at least two filter sleeves in such a device.

[0069] For maintenance, it is simply a matter of implementing the last step of this described process by simultaneously putting all the sleeves under tension until a determined average tension is reached on each sleeve.

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

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

[0072] Other objects and advantages of the present invention will become apparent from the following description, which refers to the accompanying drawings illustrating an example of an embodiment and in which:

[0073] [Fig.1] is a schematic perspective view with semi-transparent walls of an air filtration device with filter bags according to the invention.

[0074] [Fig.2] is a partial schematic view of a filter cartridge of the device of [Fig.1], of which part 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 in [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 in [Fig.2].

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

[0079] The invention relates to an air filtration device with filter bags 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 discharged. The upper body 2 is surmounted by a cap 21.

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

[0081] The device 1 also includes a vertical filter cartridge 4, comprising a peripheral cylindrical envelope 40 and filter sleeves 5, at least two, extending in the peripheral cylindrical envelope 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 one side to a lower support structure 6 and on the other side to an upper support structure 7 in the form of a tray 70 with circular openings 71. The upper support structure 7 may include at least one reinforcing frame 72 allowing the tray 70 to be stiffened, as illustrated in [Fig.1].

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

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

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

[0086] The device 1 further includes means for energizing 8 the entire set of filter sleeves 5 at a determined average voltage, in particular between thirty (30) and forty (40) kilograms, i.e. a traction force between two hundred ninety-four (294) Newtons and three hundred ninety-two (392) Newtons.

[0087] These power-up means 8 are in the form of translation means 80 of the lower support structure 6 relative to the support structure upper 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 can be in the form of three threaded rods 81 of the lower support structure 6, spaced regularly 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 one side free to rotate with the lower support structure 6, and on the other side protruding from the upper support structure 7 and having at its upper end a nut 83 fixedly attached to said threaded rod 81, as illustrated in [Fig.4].

[0090] This allows the power-up means 8 of all the filter sleeves 5 to be operated from the top of the platform 70, which is a less dangerous and dusty area for the intervention personnel.

[0091] Thus, rotating a nut 83 causes the corresponding threaded rod 81 to rotate. The device 1 may include drive means, such as, for example, removable or fixed stepper motor shafts, having end caps configured to rotate the nuts 83 simultaneously or not. It is therefore possible to translate the lower support structure 6 relative to the upper support structure by tightening or loosening the nuts 83. It is also possible to adjust the inclination of the lower support structure 6 by adjusting some of the nuts 83.

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

[0093] According to an embodiment not illustrated here, the device 1 may include means for remotely controlling the rotation of each threaded rod 81, in the form of a human-machine interface controlling a stepper motor connected to each threaded rod 81. The device 1 may also include 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 put all the filter sleeves 5 under tension remotely and safely, without having to enter the device 1, and to calculate the overall tension exerted on all the sleeves in order to deduce an average tension exerted on each sleeve 5.

[0095] The lower support structure 6 may include translational guiding means 60 cooperating with an inner vertical wall 41 of the peripheral cylindrical shell 40. These translational guiding means may be presented, as illustrated in figures 2 and 3, in the form of three rollers 600 spaced regularly on the periphery of the lower support structure 6, mounted freely in vertical rotation relative to said lower support structure 6. These rollers 600 can bear against the vertical wall 41 of the inside of the peripheral cylindrical envelope 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 suitable for hooking it to the lower support structure 6, and an assembly member 53 suitable for assembling it to the upper support structure 7.

[0097] The lock-picking mechanism 52 will be described later.

[0098] The assembly member 53 can, in a known manner, be in the form of a deformable ring attached to the upper end 51 of the sleeve 5, and it can have an annular groove extending over its outer contour, intended to fit into the inner contour of the circular openings 71 of the upper support structure 7, so as to lock 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 include individual means 54 for maintaining a voltage within a defined voltage range of each filter sleeve 5. The defined voltage range is substantially plus or minus five (5) kilograms of voltage, i.e. a voltage range of plus or minus forty-nine (49) Newtons with respect to the determined average voltage value, which is in particular between thirty (30) and forty (40) kilograms, i.e. between two hundred ninety-four (294) Newtons and three hundred ninety-two (392) Newtons.

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

[0102] The hooking member 52 of each sleeve 5 enabling its attachment to the lower support structure 6 may include a protruding 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 of bent sheet metal adapted from the lower support structure 6.

[0103] As illustrated in [Fig. 5], this attachment element 521 can be in the form of: - of a chamfered ring 522 configured to come into contact with the profile, - of 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 protruding 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 equivalent particular locking device can be envisaged, comprising individual means for maintaining a tension within a defined tension range of each filter sleeve 5.

[0106] Regarding the lower support structure 6, it can consist of a plurality of parallel folded sheet metal profiles 62 fixed to a reinforcement provided 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 central vertical part delimited by an upper end edge and a lower end edge. The lower end edge may be extended along its entire length by a right-angled return element to improve the rigidity of the profiles 62.

[0108] The upper end edge of each profile 62 may be provided with a dihedral return element consisting of a first and a second part. The first part may extend at a right angle, along a horizontal or substantially horizontal plane. The second part may extend downwards at an angle.

[0109] The return element may have several open slots 61 extending transversely over both 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 in the plate 70.

[0111] The distance between the lower support structure 6 and the upper support structure can be configured to be less than a few millimeters to a few centimeters 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 protruding rod 520 of the sleeve 5 is positioned at the flared end of the relevant open slot 61, the chamfered ring 522 being disposed under the end of the second part of the return element, thus compressing the spiral spring. The V-shape of this end 33 facilitates the insertion of the protruding rod 520 into the corresponding open slot 61

[0114] The protruding rod 520 is then simply pushed into the open slot 61 to finalize the positioning. The inclined shape of the second part of the return element allows the picking member 52 to move until it is positioned against the underside of the first horizontal part of the return element. The first inclined part of the upper return element forms a kind of stop, designed to hold the picking member 52 in position against the first horizontal part of the return element when the sleeve 6 is held taut.

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

[0116] The elastic return member 55 and more particularly the spiral spring can be a spring said to have constant force (returning) or a spring said to have constant tension (returning).

[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 process comprises the following steps: - fixing the upper ends 51 of at least two filter sleeves 5 to an upper support structure 7 by means of suitable fastening elements 53, - fixing the lower ends 50 of said at least two filter sleeves 5, by means of suitable individual hooking elements 52, to a lower support structure 6, - simultaneous tensioning of said at least two filter sleeves 5 by means of tensioning 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 ninety-four (294) Newtons and three hundred ninety-two (392) Newtons.

[0119] It should be noted that the fixing of the filter sleeves 5 in the filter cartridge 4 can be carried out at a manufacturing site for the filter cartridge 4, which is then transported to its place of use or installation. Once installed, it is possible to implement the power-up means 8 to simultaneously power up all the filter sleeves 5 to a determined average voltage.

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

[0121] The device may further include means for controlling the individual means 54 of maintaining a voltage within a defined voltage range of each filter sleeve, in the form, for example, 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 above.

[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, enabling it to be mounted in the filter cartridge 4 of the device 1.

[0124] At least one device 1 as described above may be included in an installation for capturing pollutants and then filtering and recovering them.

Claims

Demands

1. Air filtration device (1) with filter bags comprising - an upper body (2) from which the air filtered by the device (1) is discharged, - a sedimentation chamber (3), in particular funnel-shaped or cylindrical, disposed under said upper body (2), and provided with waste recovery means at its lower part, - a vertical filter cartridge (4) comprising a peripheral, in particular cylindrical, casing (40) and at least two filter bags (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 bags (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 bags (50),and on the other hand to an upper support structure (7) in the form of a platform (70) with openings, in particular circular ones (71), by means of assembly (53) of the upper ends of the sleeves (51), and - means for energizing (8) the entire set of filter sleeves (5) to a determined average voltage, characterized in that the means for energizing (8) the entire set of filter sleeves (5) are in the form of means for translating 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).

2. Air filtration device (1) according to claim 1, 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.

3. Air filtration device (1) according to any one of claims 1 or 2, characterized in that the lower support structure (6) comprises translational guidance means (60) cooperating with a vertical inner wall (41) of the outer cylindrical envelope (40) in particular in the form of rollers (600) pivoting freely vertically against said wall (41).

4. Air filtration device (1) according to any one of claims 1 to 3, characterized in that it comprises individual means for maintaining a voltage within a defined voltage range of each filter sleeve (5).

5. Air filtration device (1) according to claim 4, characterized in that the individual means for maintaining a tension within a defined tension range 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 range.

6. Air filtration device (1) according to any one of claims 1 to 5, characterized in that the hooking members (52) of the at least two filter sleeves (5) comprise a protruding 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 bent sheet metal profile (62) adapted from the lower support structure (6).

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

8. 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 any one of claims 1 to 6. 18

9. Filtration installation comprising at least one air filtration device (1) with filter bags (5) according to any one of claims 1 to 6.

Images