Drum for a drum filter

Abstract

The present invention relates to a drum (12) intended to be rotatably mounted in a drum filter (10) about an axis of rotation (X), the drum (12) having a cylindrical frame intended to support filtering panels (22), the frame of the drum (12) comprising at least two beams that extend axially, the frame of the drum (12) comprising hoops that extend circularly about the axis of revolution (R), each of the hoops being mounted between the at least two beams, the hoops being axially spaced apart from one another by a non-zero distance, the beams each comprising a trapezoidal main section, and the hoops comprising bevelled bearing ends so as to allow the bearing ends of the hoops to bear flat against the side walls of the beams.

Description

[0001] DESCRIPTION

[0002] TITLE: TAM BOUR FOR A TAM BOUR FILTER

[0003] Technical field of the invention

[0004] The present invention relates to a drum intended to be mounted in a drum filter.

[0005] Technical background

[0006] It is known to produce drum filters, for example, for water treatment upstream of an industrial plant, particularly with high liquid flow rates. Such drums can be used in particular in aquaculture installations.

[0007] This type of drum filter consists of a filter drum which is rotatably mounted in a tank partially submerged in the flow of liquid to be filtered.

[0008] The drum then comprises, circularly distributed around its periphery, in one or more rows, a plurality of filter panels. Each filter panel rests in particular on circular hoops, themselves secured to axial beams. The hoops and beams then define a drum frame which itself delimits an internal volume of the drum.

[0009] In such a drum filter, the liquid entering the tank penetrates inside the drum and then passes through the filter panels radially by gravity from the inside to the outside of the internal volume and then flows towards the outlet of the tank. Thus, debris and other impurities are deposited on the inside of the filter panels.

[0010] To facilitate the filtration of debris in the drum, it is usual for the latter to include protruding grooves in the internal volume of the drum, these grooves ensuring the mixing of the liquid in the drum.

[0011] Currently, the beams and hoops of such drums each have a "T" section and their manufacture requires the welding of many parts together. In particular, to ensure sufficient rigidity of the drum, it is necessary to multiply the reinforcement bars and crosspieces aimed at preventing deformation of the drum during use, or even breakage of this drum in the event of premature wear. Thus, the manufacture of the frame of a drum for a drum filter is tedious and requires numerous handling and operations by an operator, thus extending the manufacturing time and therefore the cost of such frames.

[0012] The present invention therefore aims to solve the aforementioned problem by proposing a drum whose elements constituting its frame have a simplified structure in their design and assembly while maintaining high filtration performance and robustness of the drum.

[0013] Summary of the invention

[0014] The invention provides a drum intended to be mounted in rotation in a drum filter about an axis of rotation, the drum having a cylindrical frame about an axis of revolution coaxial with the axis of rotation, the frame being intended to support filter panels, the frame delimiting an internal volume of the drum, the frame of the drum comprising at least two beams which extend axially and in such a way that they are angularly spaced from each other by an identical degree, the frame of the drum comprising hoops which extend circularly about the axis of revolution, each of the hoops being mounted between the at least two beams and in such a way that the hoops define a circumference of the frame of the drum, the hoops being axially spaced from each other by a non-zero distance, the beams each comprising a trapezoidal main section,and the hoops comprising beveled support ends so as to allow flat support of the support ends of the hoops against side walls of the beams.,

[0015] The advantage of such a drum is that it simplifies its manufacture by limiting the parts and welding steps required, while maintaining sufficient robustness for its use.

[0016] According to other characteristics of the invention: - the beams each comprise a radial extension which extends from an external base of each of the beams; each arch has an arc shape with an axial section in the shape of a “U”;

[0017] - the filter panels are placed resting on the hoops and are held on the frame at the level of the beams, outside the internal volume of the drum;

[0018] - the beams are made from at least one sheet whose shape is obtained by stamping;

[0019] The invention also relates to a drum filter comprising a tank provided with an inlet for a liquid to be filtered and an outlet, and comprising a drum according to any one of the preceding characteristics, the drum being rotatably mounted in the tank about the axis of rotation.

[0020] The invention also relates to a method for assembling a drum frame according to any one of the preceding characteristics, the method comprising at least a first step during which at least two sheets are deformed by stamping and assembled by a welding operation so as to form one of the beams with a trapezoidal main section, at least a second step during which at least one metal plate is stamped so as to form a hoop with a "U"-shaped axial section and at least a third step during which at least one of the support ends of the hoop is welded to one of the side walls of the at least one beam.

[0021] Brief description of the figures

[0022] Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the appended drawings in which:

[0023] [Fig.1] is a general perspective view of a drum filter comprising a drum according to an example of the invention comprising a cutaway so as to highlight an internal volume of the drum;

[0024] [Fig.2] is a general perspective view of a frame of the drum of Figure 1 comprising beams and hoops;

[0025] [Fig.3] is a radial sectional view of the drum frame of Figure 2;

[0026] [Fig.4] is a close-up radial sectional view of a beam of the drum frame of Figure 2 showing a filter panel, a tensioner and a fixing plate;

[0027] [Fig.5] is a close-up perspective view of the drum frame of Figure 2 showing fixing plates;

[0028] [Fig.6] is an axial sectional view of one of the hoops of the drum frame of Figure 2;

[0029] [Fig.7] is a detail view of a beam of the frame of Figure 2 before its assembly.

[0030] Detailed description of the invention

[0031] In the following description, identical, similar or analogous elements will be designated by the same reference numbers.

[0032] Figure 1 illustrates a drum filter 10 equipped with a drum 12 according to an example of the invention.

[0033] The drum filter 10 comprises a tank 14 provided with an inlet orifice 16 for a liquid to be filtered and an outlet orifice 18. The direction of circulation inside the drum filter 10 is represented by arrows F1 and F2. More precisely, the arrow F1 corresponds to the inlet of the fluid into the drum filter and the arrow F2 corresponds to the outlet of the filtered fluid from the drum filter.

[0034] Inside the tank 14, the drum 12 is mounted to rotate around an axis of rotation X.

[0035] In particular, the drum 12 comprises a cylindrical frame 20, visible in FIG. 2, of which an axis of revolution R coincides with the axis of rotation X of the drum 12.

[0036] The drum 12 illustrated in FIG. 1 comprises filter panels 22 which are mounted peripherally on its cylindrical frame 20. In particular, the filter panels 22 have a curved shape and they delimit a circumference of the drum 12.

[0037] The drum 12 will be described in more detail in the remainder of the detailed description in Figures 2 to 6.

[0038] In the remainder of the detailed description, it will be understood that the axial and radial directions are defined according to the axis of rotation X of the drum 12 or the axis of revolution R of the frame 20, these axes being the same.

[0039] The drum filter 10 illustrated in FIG. 1 comprises a spray bar 24 equipped with a plurality of spray nozzles 26. This spray bar 24 extends here parallel to the axis of rotation X of the drum 12, outside the drum 12, such that the fluid that it projects is capable of unclogging the filter panels 22 of the drum 12.

[0040] According to the example of the invention, the drum 12 comprises a channel arranged to recover the residues resulting from the unclogging of the filter panels 22 and so as to evacuate them outside the drum filter 10 via an evacuation orifice 25.

[0041] The drum 12 will now be described in more detail by means of Figures 2 to 6.

[0042] The frame 20 of the drum 12 comprises, according to the example illustrated and in a non-limiting manner, four beams 28 which extend axially and hoops 30 which extend circularly between the beams 28.

[0043] The hoops 30 and the beams 28 delimit in particular a circumference of the frame 20 and an internal volume 32 of the drum 12 intended to receive the liquid to be filtered as mentioned previously.

[0044] The drum 12 also includes a tubular end ring for driving the drum in rotation by means of a belt and an end disc at the other end. The tubular ring and the belt axially close the internal volume of the drum.

[0045] As seen in Figure 3, each beam 28 is arranged angularly at 90° to an adjacent beam 28.

[0046] In other words, the four beams 28 are arranged at the ends of two perpendicular diameters of the drum 12.

[0047] As seen in Figure 4, the beams 28 according to the invention each comprise a trapezoidal main section. More precisely, each of the beams 28 comprises a main section in the shape of an isosceles trapezoid, taken in a radial plane of the drum 12.

[0048] In other words, each beam 28 has the shape of a trapezoidal tube.

[0049] In the remainder of the description, the structural characteristics of a single beam 28 will be described but it is understood that these characteristics apply mutatis mutandis to all of the beams 28 of the drum 12.

[0050] It should also be considered that the drum may include more or less than four beams depending on the diameter of the drum. For example, and without limitation, the drum may include two beams when the drum has a diameter of 80cm, three beams when the drum has a diameter of 120cm, four beams when the drum has a diameter of 160cm and five beams when the drum has a diameter of 200cm.

[0051] In relation to the isosceles trapezoid shape in radial section of the beam 28, two bases 34 of the beam 28 are defined which extend parallel to each other, being connected by side walls 36.

[0052] The bases 34 of the beam 28 extend perpendicular to a radial direction of the drum 12.

[0053] According to the example of the invention illustrated, an internal base 34a and an external base 34b of the beam 28 are defined, the internal base 34a extending into the internal volume 32 of the drum 12 and the external base 34b extending on the external periphery of the frame 20 of the drum 12.

[0054] The side walls 36 of the beam 28 extend between the inner base 34a and the outer base 34b such that they each form an obtuse angle AO with the outer base 34b, and an acute angle AA with the inner base 34a.

[0055] It is then understood that the side walls 36 extend projecting into the internal volume 32 of the drum 12 and thus make it possible to form, with the filter panels 22, retention zones 37 for the residues during the filtration operation, and thus allow the mixing of the fluid and residue mixture, consequently improving the filtration. According to the example of the invention illustrated, the beam 28 comprises a radial extension 38 which extends from its external base 34b.

[0056] Thus, in a general perspective view of the drum 12 of Figure 2, the radial extension 38 takes the form of an external wall which extends radially from the external base 34b of the beam 28.

[0057] According to the example of the invention illustrated, the beam 28 is formed of two sheets 40a, 40b, visible in FIG. 7, folded in a shape mirroring each other relative to an axial plane of the drum 12 and in such a way as to form one half of the beam 28.

[0058] In particular, the shape of each of the sheets 40a, 40b can be obtained by stamping or by threading.

[0059] According to the example of the invention illustrated in Figures 4 and 7, a first sheet 40a has a “d” shaped section while a second sheet 40b has a “b” shaped section.

[0060] It is then understood that the radial extension 38 of the beam 28 corresponds to one end of each sheet 40a, 40b, not deformed, and in plane contact with each other.

[0061] Once folded, the two sheets 40a, 40b are welded to each other in such a way as to form the trapezoidal main section of the beam 28 with its radial extension 38.

[0062] It should also be considered that the beam could, in a non-limiting and not illustrated manner, be made from a single deformed sheet.

[0063] As mentioned previously, the drum 12 comprises the hoops 30 taking the form of circular arcs and which each extend circularly between two beams 28.

[0064] Thus, the hoops 30 participate in delimiting the circumference of the frame 20 of the drum 12 as visible in figure 3.

[0065] As seen in Figure 4, the hoops 30 comprise beveled support ends 42 so as to allow flat support of the support ends 42 of the hoops 30 against the side walls 36 of the beams 28 described previously.

[0066] It is then understood from the above that the beveling of the support ends 42 of the hoops 30 is turned towards the internal volume 32 of the drum 12 so as to present a complementarity of shape with the angle of inclination of the side walls 36 relative to the radial direction of the drum 12, as visible in figure 4.

[0067] According to the example of the invention illustrated, the hoops 30 here form quarter circles. It is then understood that four hoops 30 arranged in the same radial plane, between the beams 28, delimit a circumference of the frame 20 of the drum 12, as visible in FIG. 3.

[0068] Furthermore, the hoops 30 are distributed axially along the drum 12 and are spaced axially from each other by a constant distance D1, visible in figure 2.

[0069] As seen in Figure 6, the hoops 30 each have an axial section in the shape of an “II” of which a bottom wall 44 is arranged on the periphery of the drum 12 as seen in Figure 5.

[0070] The bottom wall 44 of the hoops 30 of axial “U” section thus forms a support surface for the filter panels 22 of the drum 12 as visible in figure 5.

[0071] The "II" shape of the hoops is used to advantage, as it allows them to be manufactured by stamping a single metal plate while obtaining a part of great rigidity.

[0072] According to the example of the invention illustrated in Figure 3, the filter panels 22 have a curved shape here according to a quarter of a circle so as to be arranged in support on two axially adjacent hoops 30 and between two angularly adjacent beams 28.

[0073] It is then understood that, according to this example of the invention, the filter panels 22 each have an axial dimension at least equal to the distance D1 axially separating two axially adjacent hoops 30.

[0074] The filter panels 22 are held on the frame 20 of the drum 12 at the level of the beams 28, outside the internal volume 32 of the drum 12, as visible in figures 4 and 5.

[0075] In particular, the drum 12 comprises fixing plates 46 of radial “V” section, arranged to cover the radial extensions 38 of the beams 28.

[0076] More particularly and in relation to FIG. 4, a top 48 of the fixing plates 46 is defined from which two walls 50 extend in the direction of the drum 12 so as to have a “V” shape in radial section.

[0077] Thus, the top 48 of each fixing plate 46 rests on a free end of the radial extensions 38 of the beams 28 and in such a way that the walls 50 of the fixing plates 46 extend while being directed towards the frame 20 of the drum 12.

[0078] For example, the fixing plates 46 are welded at their top 48 to the free end of the radial extension 38 of each beam 28.

[0079] According to the example of the invention illustrated and visible in Figures 2 and 5, the fixing plates 46 are arranged along the radial extension 38 of each beam 28 such that two fixing plates 46 extend on either side of each hoop 30.

[0080] Each of the walls 50 of the fixing plates 46 comprises a through hole 52 so as to allow the fixing of a holding element 53, visible in FIG. 4, of the filter panels 22 on the frame 20 of the drum 12.

[0081] According to the example of the invention illustrated and visible in Figure 4, the drum comprises tensioners 23 arranged between the filter panels 22 and the holding element 53, the tensioners 23 participating in the pressing of the filter panels 22 against the frame 20 of the drum 12.

[0082] According to a non-limiting example of the invention, the through holes 52 of the fixing plates 46 may comprise an internal thread and the holding element 53 may take the form of a screw capable of cooperating with the internal thread of the through holes 52.

[0083] Thus, according to the illustrated example of the holding element, the screw is moved in rotation via the internal thread of the through holes 52 until one end of said screw comes into contact with the tensioner 23 associated with the filter panel 22, so as to press and radially block in position the filter panel 22 on the frame 20 of the drum 12.

[0084] Alternatively, the holding elements 53 can take the form of screws in the through holes 52 of the fixing plates 46 and in such a way as to radially block the filter panels 22 in position on the frame of the drum 12 as illustrated in FIG. 4. As visible in FIG. 5, the drum 12 comprises wedges 54 which each extend between the radial extension 38 of one of the beams 28 and a bottom wall 44 of one of the hoops which is integral with said beam 28.

[0085] The wedges 54, particularly visible in Figure 4, here take the form of a flat metal plate welded to the free end of the radial extension 38 of a beam 28 and which extend towards one of the bottom walls 44 of one of the hoops 30 to which they are welded, so as to form a locking element in the axial position of the filter panels 22 when they are positioned on the frame 20 of the drum 12.

[0086] It is then understood that the fixing plates 46 ensure a locking in the radial position of the filter panels 22 while the wedges 54 ensure a locking in the axial position of the filter panels 22 on the frame 20 of the drum 12, as visible in figure 5.

[0087] According to the example of the invention illustrated, a wedge 54 extends axially between each pair of fixing plates 46 arranged on either side of the same hoop 30 as described previously.

[0088] It is then understood that according to the example of the invention illustrated, the filter panels 22 each have an axial dimensioning substantially equal to the distance D1 which separates two axially adjacent hoops 30.

[0089] A method of manufacturing the frame 20 of the drum 12 will now be described in relation to FIGS. 2 to 6.

[0090] In a first step of the process, the first sheet 40a and the second sheet 40b of each beam 28 are stamped in such a way as to give them their respective “d” and “b” shapes previously described in figure 7.

[0091] Once the two sheets 40a, 40b of each beam 28 have been stamped, they are assembled and welded to each other so as to form the beams 28 of trapezoidal section with their radial extension 38 as described previously.

[0092] Thus, the manufacture of each beam requires only one step of stamping the two sheets and their assembly by a welding operation. In a second step prior to, simultaneous with or subsequent to the first step, the U-shaped cross-section arches 30 are each formed by stamping a metal plate and their free ends are beveled so as to form the support ends 42 as described previously.

[0093] Also, we understand that the manufacture of each of the hoops only requires a step of stamping a plate and cutting their support ends.

[0094] Once the beams 28 and the hoops 30 have been manufactured, they are assembled and secured to each other by welding the support ends 42 of each hoop 30 onto one of the beams 28 according to the structural characteristics of the drum 12 described previously, so as to form the frame 20 of the drum 12.

[0095] Furthermore, the beams 28 and the hoops 30 are also welded to the tubular ring and to the end disc previously described.

[0096] The drum as just described is thus advantageous in that the manufacture and assembly of its frame are simple and quick to carry out for an operator and require little handling and welding operations, while maintaining efficiency in the mixing of the fluid mixed with the residues adequate for optimal filtration.

Claims

CLAIMS 1. Drum (12) intended to be mounted in rotation in a drum filter (10) about an axis of rotation (X), the drum (12) having a cylindrical frame (20) about an axis of revolution (R) coaxial with the axis of rotation (X), the frame (20) being provided to support filter panels (22), the frame (20) delimiting an internal volume (32) of the drum (12), the frame (20) of the drum (12) comprising at least two beams (28) which extend axially and such that they are angularly spaced from each other by an identical degree, the frame (20) of the drum (12) comprising hoops (30) which extend circularly about the axis of revolution (R), each of the hoops (30) being mounted between the at least two beams (28) and such that the hoops (30) define a circumference of the frame (20) of the drum (12), the hoops (30) being axially spaced from each other by a non-zero distance (D1),the beams (28) each comprising a trapezoidal main section, and the hoops (30) comprising support ends (42) beveled so as to allow flat support of the support ends (42) of the hoops (30) against side walls (36) of the beams (28)., 2. Drum (12) according to the preceding claim, wherein the beams (28) each comprise a radial extension (38) which extends from an external base (34b) of each of the beams (28).

3. Drum (12) according to any one of the preceding claims, in which each hoop (30) has an arcuate shape with an axial section in the shape of a “U”.

4. Drum (12) according to any one of the preceding claims, in which the filter panels (22) are arranged to rest on the hoops (30) and are held on the frame (20) at the level of the beams (28), outside the internal volume (32) of the drum (12).

5. Drum (12) according to any one of the preceding claims, in which the beams (28) come from at least one sheet (40a, 40b) whose shape is obtained by stamping.

6. Drum filter (10) comprising a tank (14) provided with an inlet (16) for a liquid to be filtered and an outlet (18), and comprising a drum (12) according to any one of the preceding claims, the drum (12) being rotatably mounted in the tank (14) about the axis of rotation (X).

7. Method for assembling a frame (20) of a drum (12) according to any one of claims 1 to 5, the method comprising at least a first step during which at least two sheets (40a, 40b) are deformed by stamping and assembled by a welding operation so as to form one of the beams (28) with a trapezoidal main section, at least a second step during which at least one metal plate is stamped so as to form a hoop (30) with an axial section in the shape of an "II" and at least a third step during which at least one of the support ends (42) of the hoop (30) is welded to one of the side walls (36) of the at least one beam (28).

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