MODULAR FILTER ELEMENT

Abstract

The present invention relates to a modular filter element comprising a first elongate hollow body, a second elongate hollow body and connection means for connecting the first elongate hollow body to the second elongate hollow body, wherein the connection means comprises a connection member that extends into a lower wall of the first elongate hollow body and into the upper wall of the second elongate hollow body to provide a gas-tight seal between the first elongate hollow body and the second elongate hollow body.

Claims

1. A modular filter element comprising a first elongate hollow body, a second elongate hollow body and connection means for connecting the first elongate hollow body to the second elongate hollow body, wherein the connection means comprises a connection member that extends into a lower wall of the first elongate hollow body and into the upper wall of the second elongate hollow body to provide a gas-tight seal between the first elongate hollow body and the second elongate hollow body.

2-41. (canceled)

42. A filter element according to claim 1, wherein the filter element comprises an internal support structure in the form of a cage member.

43. A filter element according to claim 42 wherein an elongate member depends from the cage member.

44. A filter element according to claim 43, wherein the cage member is located in an upper region of the filter element and the elongate member is located in a lower region of the filter element.

45. A filter element according to claim 43, wherein the elongate member comprises a rod, a wire or a spring.

46. A filter element according to claim 42, wherein the support structure extends through a sleeve.

47. A filter element according to claim 46, wherein the sleeve is perforated.

48. A filter element according to claim 46, wherein the sleeve is attached to the connection member.

49. A filter element according to the claim 48, wherein when the connection member is metallic, the sleeve is welded to the connection member.

50. A filter element according to claim 1, wherein the filter element comprises an end cap, the end cap comprising a perimeter wall that is configured to extend into the lower wall of the second elongate hollow body.

51. A filter element according to claim 50, wherein the filter element comprises an end cap adjustment system for adjusting the longitudinal position of the end cap relative to the filter element.

52. A filter element according to claim 51, wherein the end cap adjustment system comprises a threaded bolt configured to engage with the end cap.

53. A filter element according to claim 52, wherein the end cap is rotatably moveable along the threaded bolt.

54. A filter element according to claim 51, wherein the end cap adjustment system comprises a resilient member for maintaining contact between the end cap and the lower wall of the second elongate hollow body.

55. A filter element according to claim 54, wherein the resilient member comprises a spring.

56. A filter element according to claim 1, wherein the filter element is greater than 3 metres in length.

57. A filter element according to claim 1, wherein the filter element is a filter candle.

58. A method for forming a filter element, the method comprising the steps of: providing a first elongate hollow body having an upper wall and a lower wall; providing a second elongate hollow body having an upper wall and a lower wall; inserting a connection member into the lower wall of the first elongate hollow body and into the upper wall of the second elongate hollow body, and bringing the lower wall of the first elongate hollow body into contact with the second elongate hollow body to form a gas tight seal.

59. A support structure for a filter element according to claim 1, wherein the support structure comprises a cage member and an elongate member depending from the cage member.

60. A support structure according to claim 59, wherein the base of the elongate member is configured to engage with an end cap for closing the filter element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0039] In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

[0040] FIG. 1 shows a modular filter element in accordance with a first embodiment of the invention.

[0041] FIG. 2 shows a modular filter element in accordance with a second embodiment of the invention.

[0042] FIG. 3 shows a modular filter element in accordance with a third embodiment of the invention.

[0043] FIG. 4 shows a support structure comprising an end cap adjustment system.

[0044] FIG. 5 shows a support structure comprising a sprung end cap adjustment system.

[0045] With reference to the drawings, and in accordance with an example of the present invention there is provided a ceramic filter element 100 for filtering particulate matter from hot gas streams. The modular filter element 100 comprises a first elongate hollow body 110 formed from a ceramic material having a length of about 1.8 metres and an external diameter of between 140 and 160 mm. The first elongate hollow body 110 has a substantially tubular profile that comprises an upper wall 111, a lower wall 112 and a side wall 113 that extends between the upper wall 111 and the lower wall 112. As best shown in FIG. 1, a flange 114 is located at an open upper end of the first elongate hollow body 110. The flange 114 is configured to enable mounting of the filter element 100 to a filter housing (not shown) and in this embodiment a metallic plate 115 is used to reinforce the flange 114 since this area of the filter element 100 is known to be susceptible to fracturing. As shown in FIG. 1 the lower end of the first elongate hollow body 110 is open. The modular filter element 100 also comprises a second elongate hollow body 120. The second elongate hollow body 120 is about 1.8 metres in length and has an external diameter of between 140 and 160 mm. Accordingly, the length: width ratio of the modular filter element 100 is greater than that shown in the drawings. The second elongate hollow body 120 is formed from a ceramic material and has a substantially tubular profile. In particular, the second elongate hollow body 120 comprises an upper wall 121, a lower wall 122 and a side wall 123 that extends between the upper wall 121 and the lower wall 122. The upper end of the second elongate hollow body 120 is open while the lower end is closed with an end cap 124, the upper edge of which cuts into the lower wall 122 of the second elongate hollow body 120.

[0046] As best shown in FIG. 1 the filter element 100 comprises a connection member 130 for forming a gas tight seal between the first elongate hollow body 110 and the second elongate hollow body 120. In particular, the connection member 130 is provided in the form of a steel seal ring that is capable of cutting into the lower wall 112 of the first elongate hollow body 110 and into the upper wall 121 of the second elongate hollow body 120. As the first and second elongate hollow bodies are brought together the seal ring 130 is pushed into and along the side wall 113 of the first elongate hollow body 110 and into and along the side wall 123 of the second elongate hollow member 120 to form the gas tight seal. A ceramic based adhesive 131 is provided at the interface between the first elongate hollow body 110 and the second elongate hollow body 120 in order to reinforce the seal ring 130 and to contribute to strengthening the connection between the first elongate hollow body 110 and the second elongate hollow body 120.

[0047] In this embodiment a tubular steel cage 140 extends centrally through and substantially along the length of the filter element 100. The cage 140 comprises a plurality of longitudinal bars 141 and ring members 142 that are spaced apart along the longitudinal bars 141. As best shown in FIG. 1 a lower part of the metal plate 115 is welded to an upper region of the cage 140 in order to secure the cage 140 in place within the filter element 100.

[0048] As best shown in FIG. 4, a rectangular steel plate 143 spans the lowermost ring member 142 and is part of an assembly for securing the end cap 124 to the filter element 100 and for adjusting its position. In particular, the plate 143 and an elongate block 144 that extends upwardly from the plate 143 comprise threaded apertures that enable a bolt 145 to be secured to the cage 140. As best shown in FIG. 4, the threaded bolt passes through the end cap 124, the plate 143 and the block 144, and by rotating the end cap 124 in a clockwise or anti-clockwise direction, the location of the end cap 124 can be adjusted with respect to the lower end of the second elongate hollow body 120 to account for longitudinal expansion of the filter element when filtering hot gas streams.

[0049] As best shown in FIG. 5, the end cap 124 may be sprung. In this embodiment the lower end of the cage 140 is closed using a circular plate 146. The circular plate 146 comprises an opening and the bolt 145 extends through the opening into the interior of the hollow cage 140. A spring 147 extends along the bolt 145 between the circular plate 146 and a retaining nut 148 which secures the spring 147 on the bolt 145. This arrangement allows the end cap 124 to maintain contact with the lower wall 122 of the second elongate hollow body 120 during a filter operation despite the steel cage 140 and the ceramic filter element 100 expanding and contracting in the longitudinal direction to different extents in use

[0050] According to a second example of the invention, and as best shown in FIG. 2, there is provided ceramic filter element 200 for filtering particulate matter from hot gas streams. The modular filter element 200 comprises a first elongate hollow body 210 formed from a ceramic material. The first elongate hollow body 210 has a substantially tubular profile that comprises an upper wall 211, a lower wall 212 and a side wall 213 that extends between the upper wall 211 and the lower wall 212. The first elongate hollow body 210 in this example does not comprise an integral ceramic flange and is open at both ends. The first elongate hollow body 210 is about 2.8 metres in length and has an external diameter of 140 to 160 mm.

[0051] The modular filter element 200 also comprises a second elongate hollow body 220. The length and width of the second elongate hollow body 220 is about 2.8 metres and 140 to 160 mm respectively. As such, the length: width ratio of the modular filter element 200 is greater than that shown in the drawings.

[0052] The second elongate hollow body 220 is formed from a ceramic material and has a substantially tubular profile. In particular, the second elongate hollow body 220 comprises an upper wall 221, a lower wall 222 and a side wall 223 that extends between the upper wall 221 and the lower wall 222. The upper end of the second elongate hollow body 220 is open while the lower end is closed with an end cap 224, the upper edge of which cuts into the lower wall 222 of the second elongate hollow body 220.

[0053] The first and second elongate hollow bodies 210, 220 are joined together by a connection member 230. The connection member is in the form of a steel seal ring 230 which either cuts into the lower wall 212 of the first elongate hollow member 210 or is inserted into a groove or recess (not shown) formed in the upper wall 212. Similarly, the seal ring 230 can either cut into the upper wall 221 of the second elongate hollow body 220 or be inserted into a recess or groove formed in the upper wall 221.

[0054] As the first and second elongate hollow bodies 210, 220 are brought together the steel ring is pushed into and along the side wall 213 of the first elongate hollow body 210 and into and along the side wall 223 of the second elongate hollow member 220 to form the gas tight seal. In order to reinforce the steel ring and to strengthen the connection between the first elongate hollow body 210 and the second elongate hollow body 220, a ceramic based adhesive 231 can be provided at the interface between the first elongate hollow body 210 and the second elongate hollow body 220 and/or, in the grooves or recesses formed in the lower wall 212 and/or upper wall 221 of the first and second elongate hollow bodies 210, 220 respectively.

[0055] The filter element 200 also comprises a steel sleeve 250 having an outer diameter of about 107 mm and a length of approximately 400 mm. The sleeve 250 is located at the joint between the first elongate hollow body 210 and the second elongate hollow body 220 and is used for strengthening the connection between the elongate hollow bodies 210, 220. The sleeve 250 is welded to the steel seal ring 230. In this embodiment a tubular steel cage 240 extends centrally through the sleeve 250 and substantially along the length of the filter element 200. The cage 240 does not contact the interior surface of the sleeve.

[0056] As shown in FIG. 2, the cage 240 comprises a plurality of longitudinal bars 241 and ring members 242 that are spaced apart along the longitudinal bars 241. Since the first elongate hollow body 210 does not comprise a ceramic flange, a steel flange 214 is welded to an upper region of the cage 241 for securing the filter element 200 to the filter housing. The steel flange 214 comprises integrated venturi (not shown).

[0057] As best shown in FIG. 4, a rectangular steel plate 243 spans the lowermost ring member 242 of the cage 240. The plate 243 is part of an assembly for securing the end cap 224 to the filter element 200 and for adjusting its position relative to filter element 200. Specifically, the plate 243 and an elongate block 244 that extends upwardly from the plate 243 comprise threaded apertures that enable a bolt 245 to be secured to the cage 240. As best shown in FIG. 4, the threaded bolt 245 passes through the end cap 224, the plate 243 and the block 244, and by rotating the end cap 224 in a clockwise or anti-clockwise direction, the location of the end cap 224 can be adjusted with respect to the lower end of the second elongate hollow body 220 to account for longitudinal expansion of the filter element when filtering hot gas streams.

[0058] As best shown in FIG. 5, the end cap 224 may be sprung. In this embodiment the lower end of the cage 240 is closed using a circular plate 246. The circular plate 246 comprises an opening and the bolt 245 extends through the opening into the interior of the hollow cage 240. A spring 247 extends along the bolt 245 between the circular plate 146 and a retaining nut 248 which secures the spring 247 on the bolt 245. This arrangement allows the end cap 224 to maintain contact with the lower wall 222 of the second elongate hollow body 220 during a filter operation despite the steel cage 240 and the ceramic filter element 200 expanding and contracting in the longitudinal direction to different extents in use

[0059] According to a third example of the invention, and as best shown in FIG. 3, there is provided a ceramic filter element 300 that is suitable for filtering particulate matter from hot gas streams. The modular filter element 300 comprises a first elongate hollow body 310 formed from a ceramic material. The first elongate hollow body 310 has a substantially tubular profile that comprises an upper wall 311, a lower wall 312 and a side wall 313 that extends between the upper wall 311 and the lower wall 312. The length of first elongate hollow body 310 is about 2.8 metres while its external diameter is 140 to 160 mm.

[0060] The modular filter element 300 also comprises a second elongate hollow body 320 having a length of about 2.8 metres and an external diameter of 140 to 160 mm. Thus, the length: width ratio of the modular filter element 300 is greater than that shown in the drawings. The second elongate hollow body 320 is formed from a ceramic material and comprises an upper wall 321, a lower wall 322 and a side wall 323 that extends between the upper wall 321 and the lower wall 322. The upper end of the second elongate hollow body 320 is open while the lower end is closed with an end cap 324. The end cap 324 is in the form of a disc with a perimeter wall, the upper edge of which is configured to cut into the lower wall 322 of the second elongate hollow body 320.

[0061] A connection member 330 in the form of a steel seal ring is used to join the first and second first and second elongate hollow bodies 310, 320. The seal ring 230 either cuts into the lower wall 312 of the first elongate hollow member 310 or is inserted into a groove or recess (not shown) formed in the upper wall 312. Similarly, the seal ring 330 either cuts into the upper wall 321 of the second elongate hollow body 320 or can be inserted into a recess or groove formed in the upper wall 321.

[0062] As the first and second elongate hollow bodies 310, 320 are brought together the seal ring 330 is pushed into and along the side wall 313 of the first elongate hollow body 310 and into and along the side wall 323 of the second elongate hollow member 320 to form the gas tight seal. In order to reinforce the steel ring and to strengthen the connection between the first and second elongate hollow bodies 310, 320, a ceramic based adhesive 331 is provided at the interface between the first and second elongate hollow bodies 310, 320 and/or in the grooves or recesses formed in the lower wall 312 and/or upper wall 321 of the first and second elongate hollow bodies 310, 320 respectively.

[0063] The filter element 300 also comprises a steel sleeve 350 having an outer diameter of about 107 mm and a length of approximately 400 mm. The sleeve 350 is located at the joint between the first elongate hollow body 310 and the second elongate hollow body 320 and is used for strengthening the connection between the elongate hollow bodies 310, 320. The sleeve 350 is welded to the steel seal ring 330.

[0064] In this embodiment a tubular steel cage 340 extends from an upper region of the first elongate hollow body 310 towards the end cap 324. The cage 340 comprises a plurality of longitudinal bars 341 and ring members 342 that are spaced apart along the longitudinal bars 341. As shown in FIG. 3 the first elongate hollow body does not comprise an integral ceramic flange and therefore a steel flange 314 is welded to an upper region of the cage 340 for securing the filter element 300 to the filter housing. The steel flange 314 comprises integrated venturi (not shown).

[0065] In this embodiment, rather than extending the length of filter element 300 as in the second example (FIG. 2), the cage 340 terminates at a location above the sleeve 350. As best shown in FIG. 3 the longitudinal bars 341 of the cage taper inwards towards the centre of the cage 340 and a single longitudinal rod 345 extends downwardly from the point where the longitudinal bars 341 converge. The rod 345 extends centrally through the sleeve 350 and beyond the lower wall 322 of the second elongate body 320. The length of the cage is about 900 mm while the length of the rod 345 is about 480 mm. The rod 345 is threaded and such an arrangement means that the end cap 324 can be secured to the rod 345 and its position can also be adjusted by rotating the end cap 324 in a clockwise or anti-clockwise direction along rod 345. In some embodiments the rod 345 may be replaced by wire or by a resilient element such as a spring. In another embodiment the end cap 324 may be sprung, in which case the lower end of the cage 340 is closed using a circular plate 346. The circular plate 346 comprises an opening and the rod 345 extends through the opening into the interior of the hollow cage 340. A spring 347 extends along the rod 345 between the circular plate 346 and a retaining nut 348 which secures the spring 347 in position on the rod 345. This arrangement allows the end cap 324 to maintain contact with the lower wall 322 of the second elongate hollow body 320 during a filter operation despite the steel cage 340 and the ceramic filter element 100 expanding and contracting in the longitudinal direction to different extents in use.

[0066] The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the invention.