WO2006003064A1

WO2006003064A1 - Supporting framework for accommodating filter packets of a particle filter

Info

Publication number: WO2006003064A1
Application number: PCT/EP2005/052505
Authority: WO
Inventors: Helmut Knoedl; Martin Eggenmueller; Thomas Lehmann
Original assignee: Robert Bosch Gmbh
Priority date: 2004-07-06
Filing date: 2005-06-01
Publication date: 2006-01-12
Also published as: DE102004032541A1

Abstract

The invention relates to a particulate filter with a filter packet (1) having filter pockets (2). This filter packet is accommodated inside a tubular hollow body (6) whose inner tube (12) has a flow opening (7) on the inflow side of a flow of gas loaded with particles. The filter packet (1) is supported on the movable bearing side-end (4) inside the inner tube (12) by a one-piece or multiple piece framework structure (13, 14; 20; 33, 42) or by a flanging (50, 51) that holds the filter pockets (2).

Description

Support framework for storage Filter package of a particle filter

Technical area

Particulate filters, which are used to filter out particles from flowing media, can either be constructed according to the wall flow principle (wall flow filter) or be constructed in accordance with the matting principle. In contrast to honeycomb filters, which are generally extruded or produced by a comparable method, particulate filters constructed according to the mat principle can contain mat parts made of different materials. The base materials of the mats used range from ceramic to metallic substances, with ceramics, these are processed in the as-yet-not sintered, usually pre-dried state or, in the case of metallic substances, in the finished state. The mats produced from metallic substances are sintered in the finished state or as a tissue or as a combination thereof.

State of the art

From DE 36 37 516 Cl filter elements for dust filters are known. The filter elements are mounted in a Trenriboden between the dust gas and the clean gas side and surrounded by a dust gas entry, clean gas discharge and Staübaustrag provided housing. They are flowed through by the gases to be purified from outside to inside. From the dust adhering to the outer surface of the filter layer, they can be cleaned by periodically repeating them by means of a cleaning device to be pressurized with compressed gas. When taking over the good properties of the filter elements in tube form can be accommodated at the same time a multiple of Fütterfläche on the same installation space. For this purpose, the outer surface of the filter element to be filtered is formed of wedge-shaped cells arranged next to one another around the central axis of the filter element, which cells are similar to a tube at their upper end and converge at their lower end in a star shape on a center line. This is arranged in the direction of the individual cell bisectors. EP 0 764 455 A2 discloses a filter for filtering particulates in the exhaust gas and a device for treating exhaust gases with this particulate filter. The filter can be used, for example, on a diesel engine and, in addition to a high throughput capacity, has good durability, is also economical and has outstanding maintenance properties. The filter is manufactured by cutting an end portion of a wound material. The material in coil form is a high-temperature-resistant stainless steel which has good heat resistance. The fibers obtained by separating from the material in coil form are formed into a band, this band is sintered in a subsequent processing step, and then the sintered band is heat-treated. In the heat treatment, an aluminum slurry is applied to the sintered fibers.

EP 1 256 369 A2 relates to a filter for exhaust gas aftertreatment and a filtration process. An exhaust aftertreatment filter is proposed, which is included in the exhaust system of an internal combustion engine. The filter comprises a cylindrical filter roll extending in the axial direction, which contains a filter medium which defines a number of channels extending in the axial direction. There is a first flow section provided with flow channels, and a second filtering section with alternately closed channels, which impose a flow through the Fil¬ termedium the exhaust gas. A core section is used for filter regeneration and produces an exothermic reaction. A catalytic converter filter contains a first catalytic section which is treated with a catalyst and a second filter section with alternately closed channels.

EP 1 270 886 A1 relates to a method and apparatus for reducing nitrogen oxides in an exhaust system of a diesel engine. According to this method, soot and other constituents are retained on an electrically regenerable filter and NO _{x is} adsorbed on a NO _x adsorber. The adsorbed NO _x is later reduced to N ₂ , using thermal energy, CO and hydrocarbon, which are provided when regenerating the filter.

Filter configurations containing convolutions or corrugations are known from EP 0 765 455. There, multiple waves of a filter material band are described, furthermore, EP 1 270 886 shows the multiple waves of a filter material, wherein this is brought ge in a circular shape. Honeycomb structures can be formed according to EP 1 256 369 as corrugated-like structures with closure of the waves about an imaginary axis. A disadvantage of Fil¬ terelementen with honeycomb structures are mainly the long channels. In honeycomb structures formed filters have naturally clogged every other channel, so that the Eintritts¬ cross-section is reduced to more than 50% of the theoretically conceivable inlet cross-section, resulting in a significant pressure loss result. Furthermore, this design involves the risk that the inlet openings of the channels of a honeycomb structure become clogged with soot, and with long channels there is also the risk that they will fill with ash from the rear side, which entails a loss of area with regard to the effectively usable filter area , In the case of honeycomb structures, a radially different soot charge can occur, which results in different soot burning times, whereby this soot firing takes place inside quickly and externally delayed, which in turn leads to thermal stresses within the feeder component.

In particulate filters filter cartridges are usually introduced into tubular cavities and supported by a support disk. This support disk is cut out as a sheet metal ram. Subsequently, corresponding outbreaks are punched out of the shell component sheet metal hoop. Thereafter, the support disk is crimped or deep-drawn. In principle, a high proportion of waste is inherent in the punching process, as a result of which not inconveniently high costs occur because of the material which can not be reused but is theoretically usable. Furthermore, considerable costs arise with regard to the raw material used for the support disk when using higher-grade steel grades.

Presentation of the invention

The support framework proposed according to the invention for supporting a filter pack in a filter housing serves for its storage and allows both a compensation of the thermally induced radial and axial extensions of the filter pack. The proposed support structure is characterized by extreme cost-effectiveness and is very filigree, which contributes to weight reduction. Due to the proposed support structure, which receives a clamped at a fixed bearing point filter pack at their Losla- site, favorable vibration characteristics of the overall system of filter pack and housing are achieved, the rigidity is not insignificantly improved. Due to the filigree structure of the support structure a very good mechanical strength is obtained with the least possible Mate¬ rialeinsatz. Furthermore, the weldability considerably improves the handling of the proposed support structure in its various embodiments in mass production. Due to the construction on the proposed support structure for supporting a filter package in a GeMuse this can be very easily adapted for particulate filter, so for example Dieselpartikel¬ filter in any cross-sections.

In general, the filtration of the soot particles essentially takes place by means of a filter packet which is constructed from individual pockets arranged side by side. Die¬ ses Füterpaket subject to inherent high thermal stress. For the Losla¬ gerseite a arranged on a fixed bearing side filter pack a supporting framework in the form of a wire framework in a variety of variants is used.

In one embodiment, a plurality of support elements can be joined together in a star shape around an inner ring in a material-locking manner. A star-shaped configured first half-timbered part can interact with a second outer ring framework and connect the filter pack on its bearing side with the inner tube.

In a further embodiment variant, a star-shaped truss construction can be connected to an inner ring and a flanged edge of the inner tube, whereby the suspension of the filter pack is laid in the middle.

Furthermore, it is possible in a third embodiment variant to realize a support via a diameter-smaller inner ring, which is surrounded by a support ring of medium diameter.

In a fourth embodiment variant, the inner tube can be made shorter and the pockets of the filter pack can be joined with a solid ring cohesively wer¬. The solidly formed ring and the inner tube are connected to each other in this fourth Ausfuhrungsva¬ about the truss structure. The vibration behavior is improved by placing a solid inner ring in the middle passageway.

In a further, fifth embodiment variant of the inventively proposed Lage¬ tion of a filter pack at the movable bearing point, the support of the filter bags can be made against the inner tube by means of a bead and a flange. Both the bead and the flange are provided in the axial direction with outbreaks, which receive the individual filter bags of the filter pack. These are welded together with the flange.

drawing With reference to the drawing, the invention will be described below in more detail.

It shows:

1 shows an embodiment in which the movable bearing of the filter pack is formed by a first star-shaped framework and a second, outer ring framework,

FIG. 2 shows an embodiment variant of the solution proposed according to the invention with a single truss with central suspension of the filter pack,

FIG. 3 shows a further embodiment variant of the solution proposed according to the invention with a star-shaped framework materially connected to a support ring,

Figure 4 shows a variant of the proposed solution according to the invention with a shortened inner tube and a meander-shaped, stoff¬ conclusively connected to an outer ring truss and

FIG. 5 shows a further embodiment variant of the solution proposed according to the invention with an inner tube which is provided with a bead and a flanged edge, wherein the filter flaps of the filter packet are stored in outbreaks at bead and flanged edge.

variants

The illustration according to Figure 1 is shown in a filter pack 1, the filter bags 2 are mounted on a non-illustrated fixed bearing 3 of a hollow body 6 and at a designated reference numeral 4 movable bearing of the hollow body 6. The hollow body 6 is provided with a circular Strömungsöfmung 7 and mounted on a flange 8 at a weite¬ ren tubular hollow body.

At the floating bearing 4 of the filter pack 1 this is supported by a wire truss 5.

In the embodiment variant shown in FIG. 1, the wire framework comprises a star-shaped framework 13 as well as an annular framework 14 enclosing this Filter bags 2 of the filter pack 1 are materially connected to an inner ring 10 and an outer ring 11. The cohesive connection can be produced for example by welding. A first joint between the star-shaped truss 13 and the inner ring 10 is designated by reference numeral 15, a further, second joint between the star-shaped truss 13 and the outer ring 11 is indicated by reference numeral 16. Reference numeral 12 marks an inner tube, which is provided with a beaded edge 17. The Rmg framework 14 connects the filter pack 1 with the inner tube 12. For this purpose, the ring framework 14, which encloses the star-shaped framework 13, at an inner joint 18 to the outer ring 11 materially connected, so for example, welded, and at an outer joint 19 with the beaded edge 17 of the inner tube 12 are welded.

By the embodiment variant shown in Figure 1, the inner tube 12 and the Au¬ ßenring 11 via the ring framework 14 are materially interconnected, while the outer ring 11 and the inner ring 10 are connected stoff¬ conclusively about the star-shaped truss 13. Due to the star-shaped design of Fach¬ factory 13 results in a plurality of concentrically arranged support points, with which the filter pockets 2 of the filter pack 1 in the tubular hollow body 6 can be accommodated on the inner tube 12. The illustrated embodiments of the star-shaped truss 13 and the surrounding this ring framework 14 offer a tremendously weight-saving construction, the favorable properties in terms of Schwin¬ gungsverhaltens the entire system filter pack l / hollow body 6 and is characterized by a minimal use of materials, but not at the expense of achievable rigidity of the floating bearing 4 goes.

FIG. 2 shows a further embodiment variant of a bearing of the floating bearing point of a filter pack accommodated in a hollow body with a plurality of radially arranged filter pockets.

The illustration according to FIG. 2 shows that a star-shaped framework 20 is accommodated at the floating bearing 4 of the filter package 1, which comprises a plurality of filter pockets 2. The star-shaped truss 20 is at a joint 21 to the In¬ nenring 10 cohesively connected, so welded, for example, and at a further joint 22 to the Bördehand 17 of the inner tube 12 materially connected, so for example, also welded. The star-shaped configured truss 20 is accommodated in the flow opening 7 of the hollow body 6 and offers the particle-laden gas flow flowing into the filter pack 1 a very low flow resistance. In the embodiment variant shown in FIG. 2, the annular ring shown in FIG. truss 14 will be omitted; 2 is achieved by the Austuhrungsvariante shown in Figure 2, that the suspension of the filter pack 2 is moved in relation to the tubular ausgebilde¬ th hollow body 6 in the middle and can be referred to as a central suspension.

The flanged edge 17 of the inner tube 12 encloses the joints 22 of the star-shaped aus¬ formed framework 20, which facilitates a lightweight, automated feasible stoffschlüs¬ siges connecting the six support points of the star-shaped framework 20 with the flanged edge 17 of the inner tube 12. The suspension placed in the center of the filter pack 1 is indicated by reference numeral 23 in FIG.

The illustration of Figure 3 shows a further embodiment of a wire framework, with which a filter pack on its bearing side with a tubular hollow body cohesively, radial and Axialdehnungen compensating taken up.

From the illustration according to FIG. 3, it can be seen that the inner tube 12 of the hollow body 6 is also provided with a flanged edge 17 according to this embodiment. The inner ring 30 formed in a smaller diameter according to this embodiment is surrounded by a somewhat larger diameter support ring 31. The support ring 31 is materially connected to each of the filter bags 2 of the package Füterpaketes 1, so welded, for example. As cohesive joining process, for example, the brazing in question.

In addition, it is of course also possible to connect the support ring 31 via joining methods such as by means of screws or by riveting.

The polygon truss 33 is integrally connected at six joints 34 with the support ring 31 and at another six joints 35 with the flange 17 of the inner tube 12 materially connected, so for example welded or brazed. Although the star-shaped truss 13, 20 or 33 shown in FIGS. 1, 2 and 3 offers six support points between the crimp rim 17 and the filter pack 1, it is of course also possible to use the star-shaped trusses 13 or 20 and the polygonal truss 33 also form in another division in the circumferential direction, so that set only five or four support points instead of the illustrated in Figure 1, 2 and 3 each six support points between the filter pack 1 and the flange 17. Accordingly, in a modification of that shown in FIGS. 1 and 2, star or polygon-shaped trusses 13, 20 and 33, respectively, whose pitch in the circumferential direction is 60 °, approximately 70 ° or 90 °.

FIG. 4 shows a further embodiment variant of a truss structure for supporting a filter pack on its non-locating side on an inner tube.

The inner tube 12 shown in FIG. 4 represents a shortened inner tube 40. The filter pockets 2 of the filter pack 2 are welded to a solid ring 41 in the area of the flow opening 7 of the tube-shaped hollow body 6. The ring 41 and the shortened running inner tube 40 are connected to each other via a meander truss 42. Reference numeral 43 designates the joint of the shortened Innenroh¬ res 40 with the meandering framework 42, while reference numeral 44, the joint of the meandering truss 42 is designated by the outer ring 41. For reasons of vibration technology, a massively formed inner ring 45 is located in the flow opening 7 of the tubular hollow body 6. The mentioned joints 43 refer to the meander framework 42 and the shortened inner tube 40 between the meander framework 42 and the solid ring 41 are preferably designed stoff¬ conclusively, for example, produced by welding.

From the illustration according to FIG. 5, a further embodiment variant of a bearing of a filter pack in a tubular hollow body at its movable end in relation to the filter pack is shown in more detail.

According to this embodiment, the inner tube 12 is provided with a peripheral bead 50 and has a flange 51, which is also formed in the circumferential direction in the flow opening 7 in the inner tube 12.

The bead 50 on the inner tube 12 and the flange 51 are each provided with axial openings 52 which extend in the radial direction.

The axial outbreaks 52 run in the flow direction of the gaseous medium through the flow opening 7 parallel to the flowing medium. The receptacle 53 for the Filter¬ pockets 2 of the filter pack 1 forming axial bursts 52 extend through the bead 50, which are formed in the raw material of the hollow body 6. The peripheral flange 51 in the region of the end face of the bead 50 on the hollow body 6, on the other hand, is designed to improve the rigidity without axial outbreaks 52. The circumferential bead 50 formed in the hollow body 6 and terminating in the circumferential flanging 51 encloses the outer ends of the filter bags 2 of the filter pack 1 facing the flow opening 7 Filter bags 2 of the filter pack 1 are materially connected to the peripheral flange 51, so for example welded. The respective joints between the filter cloths 2 and the peripherally formed flange 51 are identified by reference numbers 54. At the front end of the filter pack 1, this has a massively formed inner ring 30 which, for reasons of vibration engineering, is embedded in the middle passage opening of the filter packs 1 containing the individual filter pockets 2. The use with a variable cross section is possible, ie, the hollow body 6 could for example also be formed oval, so that adjusts the same length of the filter bags 2 accordingly also an oval inner tube geometry. In the foregoing, a variable cross-section is also understood to mean a cross-section of the tubular hollow body 6 with different diameters, from which, accordingly, a corresponding inner tube geometry results.

The truss structures 13, 14, 20, 33 and 42 shown in detail in FIGS. 1 to 5 can all be manufactured very cost-effectively from a temperature-resistant wire-shaped material. Due to their low space requirement, the truss structures 13, 14, 20, 33 and 42 do not represent a significant flow resistance with respect to the particle-laden gas flow. Depending on the intended use and the diameter of the filter pack 1 to be supported on the loose bearing end 4 with the individual filter pockets 2 the truss structures 13, 14, 20, 33 and 42 with respect to the star-shaped truss structures four, five or six support points aufwei¬ sen, where the respective truss structures with the bead 17 and the radially encircling flange 51 with respect to the representation in FIG 5, cohesively connected to each other and support points can be formed forming. Depending on the number of support points, which may be dependent on the diameter of the filter pack 1 to be supported, four, five or six support points can be formed. The more Abstütz¬ points are present, the more favorable this is in terms of the vibration behavior of the tube-shaped hollow body 6 enclosed, the individual filter bags 2 having filter pack. 1

By forming the truss structures 13, 14, 20, 33 and 42 from a wire-like material, an extremely cost-effective production can be realized, which is characterized in particular by the smallest amounts of waste. Furthermore, can be achieved by erfindungs¬ according to the proposed solution of supporting a filter pack 1 in a tubular body 6 a tremendous weight reduction. In manufacturing technology simplest way, the illustrated framework batches 13, 14, 20, 33 and 42 can be adapted to different diameters, depending on the size of a particulate filter and the filter package 1 to be admitted with this. -10-

LIST OF REFERENCE NUMBERS

1 filter pack 45 inner ring

2 filter bags

3 fixed bearing 50 circulation surround inner tube

4 loose-side end 51 Circulation flare inner tube

5 Wire framework 52 Axial outbreaks

6 Hollow body 53 Holder for filter bags 2

7 Stromöfrhung 54 joint filter bags 2 with Börde¬

8 flange 51

55 Durchgangsöfrhung

10 inner ring

11 outer ring

12 inner tube

13 star-shaped framework

14 ring framework

15 first joint

16 second joint

17 Border edge inner tube 12

18 inner joint

19 outer joint

20 star-shaped framework

21 joint inner ring

22 joint outer ring

23 central suspension

30 inner ring

31 support ring

32 joints filter bags

33 polygon truss

34 joint support ring

35 joint flange edge

40 shortened inner tube

41 solid (outer) ring

42 meander framework

43 Joint inner tube

44 joint massive ring

Claims

claims

1. Particle filter with a filter bag (2) comprising filter pack (1) which is mounted in a rohrformigen hollow body (6), the inner tube (12) on the inflow side of a particle-laden gas stream has a flow opening (7), characterized ge indicates that the filter pack (1) at the loose-bearing end (4) via a one-piece or multi-part framework structure (13, 14; 20; 33, 42) or a flange (50, 51) accommodating the filter pockets (2) in the inner tube (12) is supported.

2. Particle filter according to claim 1, characterized in that the one or mehrteili¬ ge truss structure (13, 14, 20, 33, 42) at joints (14, 16, 22, 35, 43) with the inner tube (12) cohesively grooved.

3. Particle filter according to claim 2, characterized in that the joints (14, 16, 22, 35, 43) within a bead (17) of the inner tube (12).

4. Particle filter according to claim 2, characterized in that the cohesive joints (14, 16, 22, 35, 43) are designed as welded joints.

5. Particulate filter according to claim 1, characterized in that the one or mehrteili¬ conditions truss structures (13, 14; 20, 33, 42) at joints (15, 21) with an inner ring (10) of the filter pack (1) are connected cohesively.

6. Particle filter according to claim 1, characterized in that the one- or mehrteili- ge framework structure (13, 14; 20, 33, 42) at joints (34) with a support ring (31) of the filter pack (1) is integrally connected.

7. Particle filter according to claim 1, characterized in that the one-part or multi-part truss structure (13, 14, 20, 33, 42) is made of a wire-shaped material.

8. Particle filter according to claim 1, characterized in that the one-part framework structure is designed as a star-shaped framework (20), as a polygon framework (33) or as a meandering framework (42).

9. Particulate filter according to claim 1, characterized in that the multi-part Fach¬ factory structure comprises a star-shaped framework (13) and this enclosing Ring¬ truss (14).

10. Particle filter according to claim 8, characterized in that the meandering framework (42) at joints (43) with the outside of the inner tube (12) and at joints (44) with a filter pockets (2) enclosing outer ring (41) cohesively is bound.

11. A particulate filter according to claim 1, characterized in that the tubular hollow body (6) for receiving the filter pack (1) at the Strömungsöfrhung (7) has a circumferential bead (50) and a Umlaufbördelung (51), the recordings ( 53) for the fi lter pockets (2).

12. Particle filter according to claim 11, characterized in that the receptacle (53) for the filter bags (2) as Axialausbrüche (52) in the peripheral flange (51) are ausge¬ leads.

13. Particle filter according to claim 8, characterized in that the filter pack (1) mit¬ means of the star-shaped framework (20) by a centrally disposed suspension (10, 23) in the hollow body (6) is supported.