FILTER ELEMENT FOR THE FILTRATION OF EXHAUST GASES OR PROCESS GASES AND METHOD FOR MANUFACTURING SUCH A FILTER ELEMENT

Abstract

Filter element (1), in particular filter cartridge, for filtering exhaust gases or process gases, having a filter body (2) which defines a longitudinal direction (R) and is subdivided along the latter into a plurality of substantially tubular filter body elements (7, 8) which are each connected in pairs at their end portions (9, 10) pointing towards one another, wherein the filter body (2) defines an interior space (5) of the filter element (1), wherein two filter body elements (7, 8) connected together in pairs are screwed together by means of internal and external threads (11, 12) formed at their end portions (9, 10) and corresponding to one another and are additionally glued together in their contact regions by means of an adhesive (13).

Claims

1. Filter element (1), in particular filter cartridge, for filtering exhaust gases or process gases, having a filter body (2) which defines a longitudinal direction (R) and is subdivided along the latter into a plurality of substantially tubular filter body elements (7, 8) which are each connected in pairs at their end portions (9, 10) pointing towards one another, the filter body (2) defining an interior space (5) of the filter element (1), wherein two filter body elements (7, 8) which are connected to one another in pairs are screwed to one another by means of internal and external threads (11, 12) which are formed at their end portions (9, 10) and correspond to one another, and are additionally bonded to one another in their contact regions by means of an adhesive (13).

2. Filter element (1) according to claim 1, wherein the internal and external threads (11, 12) are conical, in particular slightly conical, wherein the external thread (12) tapers in the direction of an end face of the end portion (6) on which the external thread (12) is formed and the internal thread (10) is correspondingly tapered.

3. Filter element (1) according to claim 1, wherein the internal and external threads (11, 12) are threads with a substantially uniform thread pitch.

4. Filter element (1) according to claim 1, wherein the thread depth of the internal and external threads (11, 12) is in each case 5 to 20 mm.

5. Filter element (1) according to claim 1, wherein the internal and external threads (11, 12) are each a trapezoidal thread, a round thread and/or a rectangular thread.

6. Filter element (1) according to claim 1, wherein the internal and external threads (11, 12) each have a length of 50 to 200 mm in the longitudinal direction (R).

7. Filter element (1) according to claim 1, wherein the filter body elements (7, 8), which are respectively connected to one another in pairs, are adhesively bonded to one another at their end faces (15) and in the engagement region of the internal and external threads (11, 12).

8. Filter element (1) according to claim 1, wherein the adhesive (13) extends in the axial transition regions (16) between two connected filter body elements (7, 8) at least partially onto the outer surface (17) and/or inner surface (18) of the filter body (2).

9. Filter element (1) according to claim 1, wherein a layer thickness of the adhesive (13), which is preferably uniform, is 1 to 5 mm.

10. Filter element (1) according to claim 1, wherein the adhesive (13) is designed in such a way that it cures and/or sinters when heated above a specific limit temperature, the adhesive (13) ceramicizing in particular at 250 C.

11. Filter element (1) according to claim 1, wherein the adhesive (13) has particles which in particular have a particle size of up to 2 mm, preferably 0.1 to 0.5 mm.

12. Filter element (1) according to claim 1, wherein the adhesive (13) is thin liquid and/or an alumosilicate adhesive and/or a waterglass-based adhesive.

13. Filter element (1) according to claim 1, wherein the filter body elements (7, 8), which are connected to one another in pairs, are flush with one another in such a way that the outer surface (17) and/or the inner surface (18) of the filter body (2) are substantially smooth in the axial transition regions (16) between the two filter body elements (7, 8).

14. Filter element (1) according to claim 1, wherein it has the shape of a filter cartridge with a substantially hollow cylindrical filter cartridge body (2), which is closed at one end (3), in particular hemispherical, and open at its opposite end (4).

15. Filter element (1) according to claim 14, wherein a radially projecting collar (6) is integrally formed on the open end (4) of the filter cartridge body (2), in particular a substantially cylindrical collar or a substantially conical collar which tapers in the direction of the closed end (3) of the filter cartridge body (2).

16. Filter element (1) according to claim 1, wherein the filter body elements (7, 8) comprise or consist of a vacuum moulded part, in particular a fired or unfired vacuum moulded part based on aluminium silicate wool, alkaline earth silicate wool and/or polycrystalline high-temperature wool.

17. Filter element (1) according to claim 16, wherein at least one catalyst is incorporated in the vacuum moulding.

18. Filter element (1) according to claim 1, wherein the filter body (2) has a length of 1 to 6 m, preferably 4 to 6 m, and/or the filter body elements (7, 8) each have a length of 0.5 to 2.5 m.

19. Filter element (1) according to claim 1, wherein the filter body (2) has an outer diameter of 30 to 300 mm and/or a wall thickness of 5 to 30 mm, preferably of 10 to 25 mm.

20. Filter element (1) according to claim 1, wherein a material of the filter body (2) has a porosity of 50 to 90%, preferably greater than 70%.

21. Method for producing a filter element (1), in particular according to claim 1, wherein, in order to form a filter body (2) of the filter element (1), a plurality of substantially tubular filter body elements (7, 8) are each connected in pairs at their end portions (9, 10) pointing to one another, wherein two filter body elements (7, 8) to be connected to one another in pairs are screwed to one another by means of internal and external threads (11, 12) formed at their end portions (9, 10) and corresponding to one another, and are additionally glued to one another in their contact regions by means of an adhesive (13).

22. Method according to claim 21, wherein the filter body elements (7, 8) to be connected to one another in pairs in each case are adhesively bonded to one another at their end faces (15) and in the engagement region of the internal and external threads (11, 12).

23. Method according to claim 21, wherein the adhesive (13) is applied in the contact regions before the plurality of filter body elements (7, 8) are each screwed together in pairs.

24. Method according to claim 21, wherein the adhesive (13) is applied at least partially to the outer surface (17) and/or inner surface (18) of the filter body (2) in the axial transition regions (16) between two connected filter body elements (7, 8).

25. Method according to claim 21, wherein the adhesive (13) is applied with a layer thickness of 1 to 5 mm, preferably uniformly.

26. Method according to claim 21, wherein an adhesive (13) is used which cures and/or sinters when heated above a certain limit temperature, the adhesive (13) ceramicizing in particular at 250 C.

27. Method according to claim 21, wherein an adhesive (13) is used which comprises particles which in particular have a particle size of up to 2 mm, preferably 0.1 to 0.5 mm.

28. Method according to claim 21, wherein an adhesive (13) is used which is thin liquid and/or an aluminosilicate adhesive and/or a water glass based adhesive.

29. Method according to claim 21, wherein the filter body elements (7, 8) are designed in such a way that in each case two filter body elements (7, 8) to be connected are flush with one another, so that the outer surface (17) and/or the inner surface (18) of the filter body (2) are substantially smooth in the axial transition regions (16) between the two filter body elements (7, 8).

Description

[0026] Further characteristics and advantages of the present invention become clear by the following description of a design form of the filter element according to the invention with reference to the enclosed drawing. In it is:

[0027] FIG. 1 a schematic view of a filter element according to the invention according to a form of the present invention;

[0028] FIG. 2 a schematic zoom view of a connection area of the invention filter element according to FIG. 1;

[0029] FIG. 3 a schematic cross-sectional view of a part of a first filter body element of the invention filter element as shown in FIG. 1 in a non-screwed and nonbonded configuration; and

[0030] FIG. 4 a schematic cross-sectional view of a part of a second filter body element of the invention filter element according to FIG. 1 in a non-screwed and non-bonded configuration.

[0031] FIGS. 1 to 4 show schematic views of a filter element 1 according to the invention for the filtration of exhaust gases or process gases according to a design of the present invention. As can be seen from FIG. 1, the filter element 1 is formed in the form of a filter cartridge and has a substantially hollow cylindrical filter body 2, which is hemispherically closed at one, lower end 3 and open at its opposite, upper end 4 and defines an interior space 5 of the filter element 1. At the open end 4 of the filter body 2 a radially projecting conical collar 6 is formed, which tapers in the direction of the closed end 3 of the filter body 2.

[0032] The filter body 2 defines a longitudinal direction R and is divided along this into two essentially cylindrical tubular filter body elements 7, 8, which are connected to each other at their end portions 9, 10 pointing towards each other. For this purpose, the filter body elements 7, 8 have corresponding internal and external threads 11, 12 at their mutually facing end portions 9, 10, which screw them together. In addition, the end portions 9, 10 are glued together in their contact areas by means of an adhesive 13. The provision of both types of connection, i.e. gluing and screwing, is advantageous. In contrast to a pure bonding of the filter body elements 7, 8, a greater stability of the connection is achieved. Compared to a pure screw connection, it is ensured that the separating gap between the filter body elements 7, 8 connected by a screw connection is sealed against the penetration of fluids.

[0033] The two filter body elements 7, 8 are designed as vacuum moulded parts with a catalyst embedded. The vacuum moulded parts can be fired or unfired vacuum components based on aluminium silicate wool, alkaline earth silicate wool and/or polycrystalline high-temperature wool. Even if a catalyst is stored in the vacuum moulded parts in the present design form, it should be clear that it is also conceivable to have designs in which no such catalyst is stored in the vacuum moulded parts. Vacuum moulded parts can also be merely a component of filter body 2 or filter body 2 can do entirely without vacuum moulded parts. In general, the material of the filter body 2 should have a porosity of 50 to 90%, preferably greater than 70%.

[0034] The filter body 2 can normally be 1 to 6 m long, preferably 4 to 6 m, for example. As shown in FIG. 1, each of the two filter body elements 3, 4 is approximately half the total length of the filter body 2. Of course, it is also possible in other designs not shown here to form the filter body 2 from more than two filter body elements 7, 8, so that each filter body element 7, 8 constitutes a smaller part of the total length of the filter body 2. The filter body 2 can have an outer diameter of 30 to 300 mm and/or a wall thickness of 5 to 30 mm, preferably 10 to 25 mm.

[0035] FIGS. 3 and 4 in particular show how the two filter body elements 7 and 8 of this design example of an inventive filter element 1 are screwed together. For the purpose of a clearer representation, parts of the two filter body elements 7, 8 are shown in FIGS. 3 and 4 in a non-bolted and non-bonded configuration. The internal and external threads 11, 12 are threads with an essentially uniform thread pitch. These each have a length of 50 to 200 mm in the longitudinal direction R here. The thread depth of the internal and external threads 11, 12 is between 5 and 20 mm. In other designs not shown here, the internal and external threads 11, 12 can also be conical. The internal and external threads 11, 12 of the present design are partly similar to a round thread. In principle, internal and external threads 11, 12 can also be trapezoidal or flat threads.

[0036] The zoom view of a connection area 14 of the invention filter element 1 shown in FIG. 2 shows that the two filter body elements 7, 8 are bonded to each other in their contact areas, i.e. in this design example at their end faces 15 and in the contact area of the internal and external threads 11, 12, in their contact areas. In addition, the adhesive 13 in the axial transition areas 16 between the two connected filter body elements 7, 8 extends at least partially onto the outer surface 17 and inner surface 18 of the filter element 1. The layer thickness of the adhesive 13 is uniform and can, for example, be 1 to 5 mm. In this design example, the adhesive 13 is designed in such a way that it sinters when heated above a certain limit temperature. This results in a high mechanical load capacity and strength. In other designs not shown here, the adhesive 13 may also or alternatively also contain, for example, particles, be low viscosity, an aluminosilicate adhesive and/or a water glass based adhesive.

[0037] As can also be seen from FIG. 2, the two connected filter body elements 7, 8 are flush with each other in such a way that the outer surface 17 and the inner surface 18 of the filter body 2 are essentially smooth in the axial transition areas 16 between the two filter body elements 7, 8, i.e. without larger edges or projections.

[0038] With regard to further features or advantages of the features or feature combinations of the previously described design form of a filter element conforming to the invention, reference is made to the general description section in order to avoid repetitions.

REFERENCE CHARACTER LIST

[0039] a. filter element [0040] b. filter body [0041] c. closed end [0042] d. open end [0043] e. interior space [0044] f. collar [0045] g. filter body element [0046] h. filter body element [0047] i. end portion [0048] j. end portion [0049] k. internal thread [0050] l. external thread [0051] m. adhesive [0052] n. Connection area [0053] o. end faces [0054] p. axial transition area [0055] q. outer surface [0056] r. inner surface