FILTER ELEMENT

Abstract

The present invention relates to a ceramic filter arrangement comprising a ceramic filter and a support housed within the ceramic filter, wherein the support is in contact with inside walls of the ceramic filter.

Claims

1. A ceramic filter arrangement comprising a ceramic filter and a support housed within the ceramic filter, wherein the support is in contact with inside walls of the ceramic filter.

2. A ceramic filter arrangement according to claim 1, wherein the support comprises a plurality of bars and two or more reinforcing elements spaced along and connected to the bars.

3. A ceramic filter arrangement according to claim 1, wherein the support comprises a knuckle for making contact with the inside walls of the ceramic filter.

4. A ceramic filter arrangement according to claim 3, wherein the knuckle is formed by bending a section of the one or more bars substantially inwards.

5. A ceramic filter arrangement according to claim 3, wherein one or more knuckles are provided at one end of the support.

6. A ceramic filter arrangement according to claim 3, wherein the diameter of the support at the knuckles is greater than the diameter of the support above the knuckles.

7. A ceramic filter arrangement according to claim 1, wherein the support comprises a secondary support element connected to the support, the secondary support element extending radially from the support for making contact with the inside walls of the ceramic filter.

8. A ceramic filter arrangement according to claim 1, wherein the secondary support element is releasable from the support.

9. A ceramic filter arrangement according to claim 1, wherein one or more secondary support elements are provided at one end of the support.

10. A ceramic filter arrangement according to claim 1, wherein the support comprises at least two secondary support elements.

11. A ceramic filter arrangement according to claim 1, wherein the support element comprises a venturi.

12. A ceramic filter arrangement according to claim 1, wherein the length of the ceramic filter is between 1.0 and 5.0 metres.

13. A ceramic filter arrangement according to claim 12, wherein the length of the ceramic filter is between 1.5 and 3.0 metres.

14. A ceramic filter arrangement according to claim 1, wherein the support extends substantially along the length of the ceramic filter.

15. A ceramic filter arrangement according to claim 1, wherein the support and/or the secondary support element comprises a metallic material.

16. A ceramic filter arrangement according to claim 1, wherein the ceramic filter and the support are provided in the form of hollow tubes.

17. A ceramic filter arrangement according to claim 1, wherein the ceramic filter is closed at one end.

18. A ceramic filter arrangement according to claim 1, wherein the ceramic filter comprises a radially, outwardly extending flange at the end opposite to the closed end.

19. A ceramic filter arrangement as claimed in claim 1, where the ceramic filter is rigid and self-supporting and is a non-layered single-piece construction.

20. The use of a ceramic filter arrangement of claim 1 as a filter of particulates from a gas stream.

21. A method for providing a supported ceramic filter arrangement, which comprises the steps of: a. providing a ceramic filter; b. providing a support; and c. providing the support within the ceramic filter so that the support is in contact with inside walls of the ceramic filter.

22. A support for supporting a ceramic filter, wherein the support comprises a knuckle for making contact with inside walls of the ceramic filter.

23. A support for supporting a ceramic filter, wherein the support comprises a secondary support element extending radially from the support for making contact with inside walls of the ceramic filter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0038] In order that the invention may be more clearly understood an embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

[0039] FIG. 1A shows a support comprising knuckles and inwardly extending bar sections.

[0040] FIG. 1B shows an exploded view of the support comprising knuckles and inwardly extending bar sections.

[0041] FIG. 1C shows a plan view of the support.

[0042] FIG. 2 shows a first design of a secondary support element according to the invention.

[0043] FIG. 3 shows a support comprising primary and secondary support elements

[0044] FIG. 4 shows a support comprising primary and secondary support elements being provided within a ceramic filter

[0045] FIGS. 5A and 5B shows a second design of a secondary support element according to the invention.

[0046] FIGS. 1A-C shows a first example of a support (1). The support in the form of a barred enclosure having a length dimension of 2700 mm and a diameter of 100 mm. The support comprises eight vertical bars (2) disposed in a substantially spaced apart cylindrical configuration and reinforcing hoops (3) spaced along and connected to the vertical bars to form a support having a hollow tubular structure. The support comprises 10 reinforcing hoops being spaced apart at 150 mm intervals and 13 reinforcing hoops being spaced apart at 75 mm intervals. The 10 reinforcing hoops spaced apart at 150 mm intervals are located at an end of the support closest to a knuckle (4) and inwardly extending bar sections (5). The distance between the knuckle and the reinforcing hoop closest the knuckle is 100 mm, while the length of the inwardly extending bar section is 25 mm. The 13 reinforcing hoops are located at an end of the support closest to collar (6) to which the support is at least partly housed. By reducing the distance between the reinforcing elements at this end, for instance from 150 mm to 75 mm, additional support is afforded to the ceramic filter where it is most prone to fracture.

[0047] According to a second example of the invention, the support having a tubular structure and a length of 1600 mm comprises eight vertical bars (2) and reinforcing hoops spaced apart and connected to the vertical bars. In this example, 6 reinforcing hoops, spaced apart at 140 mm intervals, are located at an end closest the knuckle (4) and the inwardly extending bar sections (5), whereas 7 reinforcing hoops spaced apart at 75 mm intervals are located at an end closest the tube plate away from the knuckle and inwardly extending bar sections. The distance between the knuckle and the reinforcing hoop closest to the knuckle is 100 mm, while the length of the inwardly extending bar section is 25 mm.

[0048] In both examples, the diameter of the support at the knuckles is 120 mm, whereas the diameter of the support above the knuckles is 100 mm. Similarly, the diameter at tips of the inwardly extending bar sections is 100 mm.

[0049] It has been found that the supports according to example 1 and example 2 are very suitable for retaining the ceramic filter when the ceramic filter is fractured. It was additionally found that the support comprising knuckles could be easily inserted into the ceramic filter without causing damage to the inside walls of the ceramic filter.

[0050] FIG. 2 shows a first design of a secondary support element (7a). The secondary support element comprises a substantially rectangular body (8). The rectangular body exhibits a slight s-profile. This is due to the rectangular body being slightly inclined at one end and slightly declined at the other. The inclined end (9) of the body has an outer edge that is adapted for gripping an inside wall of a ceramic filter. The declined end (10) of the body in conjunction with two flaps (11, 12) that extend from each longitudinal edge of the body are used to attach the secondary support element to reinforcing hoops (3).

[0051] As shown in FIG. 3, the declined end of the body fit inside a hoop (3) of the support. The two flaps remain outside the support and press onto the vertical bars (2). This means that when the secondary support element is fitted, there is enough pressure to retain the secondary support element on the barred enclosure. For further security, the declined end of the body may be bent around the hoop after the secondary support element has been secured to the support, ensuring that the secondary support element cannot be easily removed.

[0052] FIG. 4 shows a ceramic filter (13), a support (1) in the form of a barred enclosure and secondary support elements (7a) at one end of the barred enclosure. The support is provided inside the ceramic filter by sliding the end comprising the secondary support elements into the ceramic filter first. This means that the rectangular body (8) of the secondary support element enters the ceramic filter before the inclined end (9) of the body. This ensures that damage to the inside walls of the ceramic filter is minimised. Once inside the ceramic filter, the rectangular body, extending axially outwards, causes the inclined end of the rectangular body to press tightly against the inside wall of the ceramic filter, which ensures that the ceramic filter is retained in the event it is fractured.

[0053] FIGS. 5A and 5B shows a second design of a secondary support element (7b), which comprises a rectangular body (14) having an inclined tab (15) at one end of the body and a blade section (16) at the opposite end that is slightly inclined with respect to the plane of the body. The secondary support element additionally comprises inclined flaps (17, 18) extending along the longitudinal edge of the body. The secondary support element is secured to the support (2) by positioning the secondary support element inside the barred enclosure and bending the inclined tab and inclined flaps around a hoop (3) and vertical bars (2) respectively. This causes the blade section of the secondary support element to extend radially outwards from the barred enclosure.

[0054] Any number of secondary support elements (7a) may be attached to the support (1). However, by attaching four secondary support elements at one end of the support and inserting this end of the of the support into the ceramic filter (13) first, the full weight of a ceramic filter was supported when the ceramic filter was fractured, even when the fracture occurred at an end closest to a tube sheet to which the ceramic filter is connected. It was also found that a support comprising two secondary support elements (7b) was sufficient for retaining the ceramic filter and its associated dust cake when the ceramic filter became fractured at the end closest to the tube sheet. This has the advantage that the filtering operation does not have to be halted and the particulate matter to be filtered is not contaminated with ceramic material from the fractured ceramic filter.