GB2598099A

GB2598099A - Filter for gas turbine intake

Info

Publication number: GB2598099A
Application number: GB2012550.6A
Authority: GB
Inventors: De Arcangelis Gianluca
Original assignee: Trans Technology Europe Ltd
Current assignee: Trans Technology Europe Ltd
Priority date: 2020-08-12
Filing date: 2020-08-12
Publication date: 2022-02-23
Also published as: GB202012550D0

Abstract

A v-panel inlet filter system comprising filter 1 and support structure (2, fig. 5). The v-type filter comprises a closed (12, fig. 5) and open (11, fig. 5) end opposed to each other. A first 14 and second (15, fig. 5) face, positioned opposite to each other, extend between the two ends. The faces are closer at the closed end than at the open end providing a v-shape. The filter comprises connection plates 1823 and 1821 extending between the faces and able to connect to the support frame (2, fig. 5) via connection members 21 that extend through the open end. Flange 17 at the open end and end panel 16 at the closed end act to hold the filter together. The faces may have filter material (141, 151, fig. 5) associated with them which may be pleat packs. The filter system may comprise side panels 181 that are in contact with the first and second face and extend from the open end, tapering, to the closed end. These panels may comprise two portions, one closer to the open end and one closer to the closed end and these portions may be joined by connection plate 4.

Description

Filter for Gas Turbine Intake

Field of disclosure

100011 The present invention generally relates to v-panel filters Background [0002] Filters have been used in many applications to remove particulate matter from a fluid flowing through the filter. When filtering physical matter, a filter comprises a porous material through which the fluid can flow. Filters can be used in a variety of technological areas, from swimming pool filters to vacuum cleaners to internal combustion engines to gas turbines.

10003] For example, in relation to gas turbines (or 'combustion turbines'), they come in various different forms and are used in many different applications; such as power stations, pumps (e.g. for gas pipelines), and powering vehicles (including marine vessels, locomotives, jet propulsion in, say, aircraft). The general operation of a gas turbine is well known and involves four theoretical stages: 1) isentropic compression, 2) isobaric combustion, 3) isentropic expansion, and 4) heat rejection. Those steps in combination are also called the Brayton Cycle or the Joule Cycle.

[0004] Examples where one or more filters can be used in a gas turbine include the air intake. In the gas turbine, air is taken in and compressed, and then mixed with fuel. The mixture is then ignited (burned) to create a hot gas. That hot gas can be channelled over blades of a turbine to create rotational motion of the blades about their axis and thereby rotate the drive shaft of those blades. The rotating drive shaft can cause rotation in other members (such as generators, compressors, pumps, propellers of a marine vessel or other machinery).

[0005] Filtering the air that enters the gas turbine assists in preventing blade fouling, erosion, corrosion and asset integrity. Placing an air filter in the air intake of a gas turbine is therefore critical to the longevity, mechanical efficiency and cost efficiency of the gas turbine.

[0006] While ensuring a clean air to the gas turbine is mandatory (particularly as newer gas turbines can be more sensitive to water/dust ingress), it comes at the cost of reducing the rate of flow of the fluid since the air filters provide a resistance measured as pressure drop. In a gas turbine, pressure drop through the air intake filters has a quantifiable cost, usually around 0.15% in output Vs 100Pa.

100071 An example of a conventional filter l' for a gas turbine is shown in Figs. 1 to 32. Fig. 1 shows a side view of a conventional filter l' mounted on a support structure 2' that holds the filter I' against a wall 3 of a fluid passage Fig. 2 shows a top-down view of the filter l' through line A'-A' of Fig. I. Fig. 3 shows a view of the conventional filter l' as seen from the open end 12'. Such a filter is sometimes called a v-panel filter and has a cavity 13' defined by a first face 14', a second face 15' an end plate 16' at a closed end 11' of the filter and an opening at an open end 12' of the filter I'. The first face 14' and the second face 15' of the v-panel filter l' are closer at the closed end 11' than at the open end 12'. Fluid passing through the opening enters the cavity 13' and is then filtered through filter material at the first face 14' and the second face 15'. In order to increase the efficiency of the v-panel filter l', different types of filter material can be used. For example, a denser filter material will filter more particulates from the fluid passing through the filter material, but will cause a greater drop-off in fluid velocity.

100081 Pleated filter packs, in which the filter media uses a folding pattern, allow an increased surface area of the filter medium which results in a reduction of pressure drop (unless exceptional circumstances, e.g. when the media is plated too much such that the remaining space between the pleats is ineffective). An example of a pleated filter can be seen in U52019/0234307A1, which relates to a filtration system, particularly for cleaning the intake of a gas turbine, including a flow channel surrounded by walls with an inflow opening and an outflow opening, a partition wall with at least two openings between a dirty side and a clean side which is positioned between the inflow opening and the outflow opening and limited by the walls of the flow channel, and at least two filters for purifying a flowing fluid. At least one filter is installed at a first opening on the dirty side of the partition wall and at least one filter at a second opening on the clean side of the partition wall. Arrangements such as that shown in US2019/0234307A1 focus on the increasing the number of filters within a flow channel without increasing the size of the flow channel, but do not focus on improving fluid flow through individual filters to improve the fluid flow thorough the filter system as a whole.

[0009] Accordingly, there is a need for a filter that can effectively filter particulates from a fluid flowing therethrough while minimising the pressure drop across the filter. An improvement to the filtration efficiency, and dust holding capacity, can extend the filters' usable lifetime.

Means for solving the problem [0010] The inventor have devised novel and inventive filter. A broad description will be given of specific aspects of the invention. Preferred features of the specific aspects are set out in the dependent claims.

[0011] In accordance with the present invention, there is provided a filter as set out in claim 1 and a filter system as set out in claim 10. Other aspects of the invention can be found in the dependent claims.

[0012] In a preferred embodiment, a filter comprises a closed end, an open end opposed to the closed end, a first face extending between the closed end and the open end, a second face opposite the first face, the second face extending between the closed end and the open end, wherein the first face and the second face are closer at the closed end than at the open end, at least one connection plate extending from the first face to the second face and being operable to connect to a support frame that has connection members that extend through the filter from the open end, wherein a distance between the open end and the connection plate is less than a distance between the open end and the closed end.

[0013] In some embodiments, a filter comprises a first sheet of filter material associated with the first face and a second sheet of filter material associated with the second face, wherein the first and second sheet of filter material are closer at the closed end than at the connection plate. Preferably, the first sheet of filter material and the second sheet of filter material are in physical contact at the closed end. Preferably the sheets of filter material are pleat packs.

[0014] In some embodiments, the filter comprises an end plate parallel to the at least one connection plate, the end panel being at the closed end.

[0015] Some embodiments comprise two connection plates.

[0016] In some embodiments, the filter comprises a filter frame haying a flange at the open end, and first side panel and a second side panel, wherein the first side panel and the second side panel are both in contact with the first face and the second face, and wherein the first side panel and the second side panel taper from a widest point at the flange toward a narrowest point at the closed end Preferably, the first side panel includes a main portion and a closed end portion, the closed end portion being closer to the closed end than the main portion and is offset from the main portion toward the second side panel. Preferably, the second side panel includes a main portion and a closed end portion, the closed end portion being closer to the closed end than the main portion and is offset from the main portion toward the first side panel.

[0017] In some embodiments, at least one connection plate consists of a connection plate in contact with the first side panel and another connection plate in contact with the second side panel.

100181 A filter system according to the invention comprises a filter as described above and a support frame, the support frame comprises a base plate having a hole therethrough and at least one connection means, wherein the base plate is located at the open end of the filter and wherein the at least one connection members connects to the at least one connection plate.

[0019] Advantageously, the filter of the present invention can bring two sheets of filter material closer together at the closed end of the filter. The pressure drop can therefore be reduced, the strain on the filter material can be reduced and filter efficiency can be improved. In addition, the connection plates allow a more robust connection to a support frame, thereby allowing the filter to be subject to higher fluid flows than some designs, such as bag filters. In addition, the amount of filter material used is increased and the dust-retaining capacity is increased.

Brief description of the drawings

[0020] Various embodiments and aspects of the present invention are described without limitation below, with reference to the accompanying Figures in which.

[0021] Fig. 1 is a top-down view of a conventional v-panel filter.

S

[0022] Fig. 2 is a side view of a conventional v-panel filter.

[0023] Fig. 3 is a view of a conventional v-panel filter from the open end of that filter.

[0024] Fig. 4 is a perspective view of a filter.

[0025] Fig. 5 is a top-down, cross-sectional view of a filter.

[0026] Fig. 6 shows a filter through line A-A of Fig. 5.

[0027] Fig. 7 shows a filter through line B-B of Fig. 6.

[0028] Fig. 8 shows a filter through line C-C of Fig. 6.

[0029] Fig. 9 is a top-down view of a filter mounted on a wall.

[0030] Fi. 10 is a side view of a filter mounted on a wall.

[0031] Fig. 11 is a view of a filter from the open end of that filter.

[0032] Fig. 12 shows a side view of a filter.

[0033] Fig. 13 shows a view through line D-D of Figure 12.

[0034] Fig. 14 shows a sheet of filter material.

Detailed description of a preferred embodiment

[0035] The following description relates to a filter 1, and more particularly to a v-panel filter (sometimes termed a Pak filter or a v-shaped filter). A v-panel filter is a fluid filter having two sheets of filter material that are closer at one edge than at an opposing edge. The filter 1 has a flange 17 at an open end 11 and an end panel (or,end piece') 16 at a closed end 12 (or, 'apex'), and encloses a cavity 13 between two opposed faces 14, 15 that taper toward each other at the closed end 12. When in use, the filter 1 connects to a support structure 2 that has one or more connection member 21 (also termed fingers) that extend through the filter 1 and connect to connection plates 1813, 1823 of the filter 1. The connection plates 1813, 1823 are located closer to the open end 11 of the filter 1 than the end panel 16. The faces 14, 15 of the filter 1 can therefore be closer together at the end panel 16 as the distance between those faces 14, 15 is not constrained by the diameter of the one or more connection member 21.

[0036] In the present specification, reference to the 'dirty side' of a filter I_ or filter system relates to the upstream side of the filter 1 or filter system (the side generally facing the direction from which the fluid is arriving at the filter 1) and reference to the 'clean side' of a filter 1 relates to the downstream side of the filter I (the side generally facing the direction in which the fluid leaves the filter 1).

[0037] Fig. 4 shows a perspective view of a filter system comprising a filter 1 according to preferred embodiments. More particularly, as can be seen in Fig. 4, the filter 1 is preferably a v-panel filter I_ (also called a Pak filter or a v-shaped filter). Figs. 5-8 show various angles of the filter shown in Fig. 4. In Figs. 4 to 8, the filter 1 is shown as part of a filter system, where the filter system comprises the filter 1 and a support structure 2. It will be appreciated that the filter 1 can be provided without the support structure 2. As can be seen in Fig. 5, a filter 1 comprises a first face 14 and a second face 15. Each of the first face 14 and second face 15 has an associated sheet of filter material 141, 151. The sheets of filter material 141, 151 are preferably pleated to increase the surface area of the sheet of filter material such as a pleat pack. The first face 14 and the second face 15 are closer at the closed end 12 than at the open end 11 such that the first face 14 and the second face 15, and hence the associated sheets of filter material 141, 151, form a v-shape when viewed from the top, as shown in Figs. 4 and 5. The distance between the first face 14 and the second face 15 increases as it moves away from the closed end 12 toward the open end 11, thereby creating a cavity 13 in the filter 1.

[0038] The first face 14 and the second face 15 are preferably both generally quadrilaterals, and more preferably are generally rectangular in shape (wherein rectangular comprises four sided quadrilaterals with right-angle corners), with the corners at the closed end removed, as shown in Figs. 4, 6 and 10. In Fig. 5, the first face 14 and the second face 15 contact an end panel 16 at the closed end 12 of the filter 1 and a flange 17 at the open end 11 of the filter 1. The flange 17 has an opening therethrough to allow fluid to pass through the flange 17 and into the cavity 13, or for fluid to pass out of the cavity 13 through the flange 17 depending on the direction of fluid flow.

[0039] When mounted, the v-shaped filter 1 is fitted over a support structure 2 such that the support structure 2 extends through the opening created by the flange 17 and into the cavity 13. The support structure 2 includes one or more connection members (or 'fingers') 21 extending away from a base plate 22. Preferably, the fingers 21 are rods. Preferably, the support structure 2 comprises two fingers 21 as show in Fig. 6. The plane of the base plate 22 (i.e. the plane that contains the two longest extensions of the base plate) is preferably perpendicular to the length (longest dimension) of the one or more connection members 21, and will have a hole through the middle to allow the passage of fluid into or out of the filter 1. In the arrangement shown in Fig. 6, there are two connection members 21 and the hole of the base plate is between the locations at which the connection members 21 connect to the base plate 22. When mounted, the hole through the flange 17 of the filter 1 will be aligned with the hole through the base plate 22 such that fluid can pass through the base plate 22 and the flange 17 when the fluid is entering or exiting the cavity 13.

[0040] The connection members 21may have a screw thread at the end remote from the base plate 22. In this way, a nut 5 can be used to secure the filter Ito the support structure 2 once the fingers 21 have extended through the connection plates 1813, 1823 of the filter 1, as can be seen in Figs. 4 to 8. Other methods of securing the filter Ito the support structure 2 would be apparent to a person of skill in the art.

[0041] In Figs, 4, 6 and 10, the sides 181, 182 of the frame 18 are contoured according to the shape of the filter material 141, 151. The first side 181 of filter frame 18 includes a closed end portion 1811 that is offset from a main portion 1812 of the first side 181 toward the second side 182 of the filter frame 18. The main potion 1812 of the first side 18, as can be seen in Fig. 7, is a trapezium in a plane perpendicular to the width of the first and/or second face 14, 15. At the narrow end of the trapezium, the first side 181 includes a connection plate 1813 that extends from the main portion 1812 of the first side 181 toward the second side 182. The connection plate 1813 is preferably parallel to the plane of the opening in the flange 17 of the filter L The closed end portion 1811 of the first side 181 extends from the connection plate 1813 toward the closed end 12 of the filter 1 and connects to the end plate 16.

[0042] Similarly, the second side 182 of filter frame 18 includes a closed end portion 1821 that is offset from a main portion 1822 of the second side 182 toward the first side 181. The main potion 1822 of the second side 182, as can be seen in Figs. 4 and 8, is a trapezium in a plane perpendicular to the width of the first and/or second face 14, 15. At the narrow end of the trapezium, the second side 182 includes a second connection plate 1823 that extends from the main portion 1822 of the second side 182 toward the first side 181. The second connection plate 1823 is preferably parallel to the plane of the opening in the flange 17 of the filter 1. The closed end portion 1821 of the second side 182 extends from the second connection plate 1823 toward the closed end 12 of the filter 1 and connects to the end plate 16. The end plate 16 therefore connects the first and the second sides 181, 182 at the closed end 12 of the filter 1.

[0043] In the preferred embodiment, the filter 1 comprises a filter frame 18 into which a first sheet 141 of filter material associated with the first face 14 and a second sheet 151 of filter material associated with the second face 15 are mounted. The frame 18 includes an opening at the open end 11 of the filter 1, and further includes two sides 181, 182 extending away from the open end. The first and second sides 181, 182 connect to the end plate 16.

[0044] In Figs. 4-8, the filter 1 is shown as being constructed of two sections connected together at a join 4. The join 4 extends laterally around the filter 1 and assists in holding the filter material 141, 151 in the filter 1. The arrangement shown in Figs. 4-8 could equally be constructed of a single section such that no join 4 would be present.

[0045] Some of the differences over the conventional v-panel filter will be apparent when comparing Figs. Ito 3 to Figs. 9 to 11. Figs. 9 and 10 show a filter system comprising a filter 1 and a support structure 2. The support structure 2 is shown as connecting the filter Ito the wall 3 of a fluid passage. As with the arrangements of Figs. 4-8, connection members 21 of the support structure 2 connect to the filter 1 at a connection plates 1813. 1823. The point at which the first and second faces 14, 15 are closest is further away from the open end 12 of the filter 1 than the connection plates 1813, 1823.

[0046] At the end plate 16, the first sheet 141 of material and the second sheet 151 of material are physically close than at the connection plates 1813, 1823. In preferred embodiments, the first sheet 141 of filter material and the second sheet 151 of filter material are in physical contact with each other at the end plate 16. Fig. 11 shows a view from the open end 11 of the filter 1, and shows the first face 14 and the second face 15 being closer at the end plate 16 than at the connection plates 1813, 1823. In the arrangement of Fig. 11, the end plate 16 can be seen between the first face 14 and the second face 15. The first and second sheet 141, 151 of filter material, when mounted in the filter frame 18, may obscure the end plate 16 from view through the open end 11 through the flange 17. This is in contrast to a conventional v-panel filter 1' shown in Figs. 1-3, in which the first face 14' and the second face 15' are closest at the end panel 16'. As can be seen in Fig. 3, the size of the end panel 16' of the conventional filter l', in a direction between the first face 14' and the second face 15', is limited by the diameter of the fingers of the support frame to which the conventional filter l' is to be attached. Sheets of filter material mounted in the conventional filter 1' are therefore spaced at least by the diameter of the fingers.

[0047] Fig. 12 shows the first face 14 of a filter frame 18. A corresponding view and description applies to the second face 15 and so is not repeated. The first connection plate 1813 and second connection plate 1823 are closer to the flange 17 than the end panel 16. The first and second connection plates 1813, 1823 are both at the narrow end of the filter 1. The side panels 181, 182 have associated retaining means. In Fig. 12, the retaining means are shown as lips 1814, 1824. It will be apparent that other retaining means are envisaged. Then a sheet of filter material 141 is mounted in the filter frame 18, the lips 1814, 1824 of the side panels 181, 182 overlap the edges of the sheet of filter material to prevent the sheet of filter material detaching from the filter frame 18. When the distance between the connection plates 1813, 1823 and the flange 17 (or open end 12) is less that the distance between the side panels 181, 182, the lips 1814, 1824 associated with the side panels 181, 182 can be sufficient to retain a filter sheet.

[0048] Fig. 12 also shows a lip 1834 associated with the end plate 16 and the connection plates 1813, 1823. Fig. 12 also shows a lip 1844 associated with the flange 17. Those lips 1834, 1844 serve as retaining means that allows a simple yet robust arrangement to keep a sheet of filter material mounted in the filter 1. The lips 1814, 1824 associated with the side panels 181, 182 in Fig. 12 extend from the open end of the filter 1 (i.e. from the flange 17) to the connection plate 1813, 1823. In other arrangements, the lips 1814, 1824 associated with the side panels 181, 182 can also extend from the connection plates 1813, 1823 to the end plate 16.

[0049] Fig. 13 shows a view through line D-D of Fig. 12 with the first sheet of filter material 141 and the second sheet of filter material 151 mounted in the filter 1. The end panel (or 'end piece') 16 has a generally semi-circular cross-section. When the cavity 13 is on the dirty side of the filter I, the semi-circular cross section of the end piece 16 reduces the building up of stagnant fluid caused by fluid incident on the end piece 16. In Fig. 13, the first sheet of filter material 141 is closest to the second sheet of filter material 151 at a point more remote from the flange 17 than the connection plate 1823.

[0050] Bringing the first sheet of filter material 141 and the second sheet of filter material 151 closest together at a point further from the open end 12 than the connection plates 1813, 1823 improves the efficiency of the filter. In an example where fluid flow is incident on the end plate 16, with the cavity 13 downstream of the filter material 141, 151, an area of high pressure will be generated at the end plate 16 (and any connection plate) as fluid cannot flow therethrough and will be forced to change direction before flowing along the first or second face 141, 151 of the filter 1. The fluid that has changed direction before flowing along the first face 14 or second face 15 will mix with the fluid that is directly incident on the first face 14 or second face 14, and will lower the velocity thereby increasing the distance from the first face 14 or second face 15 to an area of laminar flow of the fluid. As a larger end panel causes a larger area of high pressure, the volume of fluid changing direction will be greater, the laminar flow will be more remote from the first or second face 14, 15 and the force of the fluid on the sheets of filter material will be reduced and the rate of fluid passing through the sheets of filter material 141, 151 will be reduced. The larger the gap between the sheets of filter material 141, 151 at the apex of the filter, therefore, the greater the pressure drop. By haying an arrangement in which a support structure 2 connects to the filter 1 at a point closer to the open end 11 than the end plate 16, the filter media 141, 151 can be closer together at the end plate 16, thereby mitigating the pressure drop. In addition, the Such a filter arrangement therefore reduces emissions, and lowers gas consumption. When mounted to the air inlet of a Gas Turbine, this leads to a reduction in Gas Turbine output/efficiency caused by the inlet pressure drop.

[0051] Similarly, when the sheets 141, 151 of filter material are present, the cavity 13 is defined by the first sheet 141 of filter material, the second sheet 151 of filter material, the two sides 181, 182, the end structure 16 and the plane of the opening in the flange 17 at the open end 11 of the filter 1. When a fluid moves from the cavity 13 through the sheets 141, 151 of filter material, there will be high pressure on the cavity side of each side of filter material 141, 151 (i.e. the dirty side of the filter material), with an area of high pressure being at the end panel 16. If the fluid encounters the end panel 16 and not the filter material, it will have to change direction as it cannot pass through the end panel 16. With a larger end panel 16, a larger volume of fluid will need to change direction, and will mix with the laminar flow of fluid entering the cavity 13 from the opening in the flange 17. A smaller distance between the first sheet of filter material 141 and the second sheet of filter material 151 therefore has a similar effect when fluid is moving from the cavity through the filter material as when the fluid is moving from the filter material into the cavity.

[0052] Turning again to Figs. 4, 7 and 8, two grooves 1812a, 1822a can be provided in each side panel 181, 182 to retain the sheets of filter material 141, 151 respectively in the filter 1. Each groove 1812a of the first side panel 181 is a section that is indented away from the second side panel 182 relative to a main portion 1812b of the first side panel 181. Each groove 1822a of the second side panel 182 is a section that is indented away from the first side panel 181 relative to a main portion 1822b of the second side panel 182. Figs. 4, 7 and 8 show the grooves 1812a, 1822a as part of the main portion 1812, 1822 of the first and second panels 181, 182. Some embodiments also include similar grooves in the closed end portion 1811, 1821 of the first and second panels 181, 182. Instead or in addition, the side panels 181, 182 can include lips 1814, 1824, as can be seen in Figs. 4, 6 and 11-13, that partially extend into the first and second face 14, 15 to help hold the sheets of filter material 141, 151 in place. When the sheets of filter material 141, 151 are mounted in the filter, the lips 1814, 1824 are on the other side of the sheets of filter material 141, 151 than the cavity 13 and so retain the respective sheet 141, 151 of filter material in place. The sheet of filter material 141, 151 is therefore less likely to flex sufficiently to come free of the filter frame 18. Similarly, the end plate 16 may include a lip that extends partially across the first face 14 toward the open end 11 of the filter 1 and may include a lip that extends across the second face 15 toward the open end 14 of the filter Ito further assist in retaining the sheets of filter material 141, 151.

[0053] Turning again to Figs. 4, 6 and 10, the first and the second face 14, 15 of the filter 1 are generally rectangular, but without the corners at the closed end 12 of the filter I. The filter material is of a similar shape. More particularly, the first and second sheet 141, 151 of filter material can be the same shape that is comprised of two regions The first sheet 141 of filter material, associated with the first face 14, will be discussed here in relation to Fig. 14, although it will be appreciated that a similar description applies to the second sheet 151 of material. In the discussion, the width of the face 14 is the direction across the face 14 and between the two sides 181, 182 of the filter 1, and the length of the face 14 is the direction perpendicular to the width and across the face 14 between the open end H of the filter 1 and the closed end 12 of the filter L [0054] Fig. 14 depicts a sheet of filter material 141, and shows the first region 1411 and the second region 1412 separated by a dashed line, which is provided for illustrative purposes. The first and second regions 1411, 1412 are both rectangular (wherein rectangular comprises four sided quadrilaterals with right-angle corners), and the sheet 141 of filter material has a line of symmetry in a length-wise direction. The first region 1411 is rectangular having a width the same as the first face 14 of the filter 1. The first region 1411 has a length less than the distance between the open end 11 of the filter 1 and the closed end 12 of the filter 1 at the line of symmetry. The second region 1412 has a width less than the width of the first region 1411 and a length less than the length of the first region 1411, where the combined length of the first region 1411 and the length of the second region 1412 is the same as the length of the first face 14 of the filter 1 at the line of symmetry. When the sheet 141 of filter material is mounted in the filter frame 18, therefore, the sheet 141 abuts the lip 1814, 1824 of the first side 181 and the second side 182, and is retained in place. The shape of the sheet 141 of filter material is the same for the first and second sheet 141, 151 of filter material in the preferred embodiment.

[0055] The sheets 141, 151 of filter material therefore have additional filter material when compared to a filter pack of a conventional filter. Particularly, the second region 1412 will be between the extensions of the connection members 21 when the sheet of filter material 141 is mounted in a filter 1 that is itself attached to a support structure 2.

That area is not used in a conventional filter system. The preferred embodiment therefore allows for additional filter material, beyond the point at which the connection members connect to the filter 1, to be included in the filter 1 without altering existing support structures 2. In some arrangements, the connection members 21 do not extend beyond the connection plates. Such an arrangement would still include additional material extending beyond the connection plates compared to a conventional filter where the fingers 21 connect to the end panel and no filter material is present beyond the point of connection. The additional material provides increased surface area, which results in a lower pressure drop and higher filtration efficiency.

[0056] In some implementations, such as in advanced self-cleaning (ASC) and/or superior self-cleaning (SSC) systems, the above described filter 1 will be mounted to a support frame 2 that is attached to a wall 3 of a fluid passage, as shown in Figs. 9 and 10. There may be limited space between the end of the fingers 21 of the support frame 2 and an opposed wall of the fluid passage (not shown). Having the filter material 141, 151 between the connection members 21 of the support frame 2 maximises the amount of filter material that can be present in the fluid passage, thereby increasing the efficiency of the system as a whole in terms of the down-stream fluid flow, reducing the strain on the filter material and increasing the dust holding capacity. In turn, this leads to an increased time between replacing filters.

[0057] The filter 1 described above can be attached to a number of different devices, including vacuum cleaners, gas turbine intakes, air-conditioning units, dry cleaning exhausts, vehicle engines and so forth In a preferable implementation, the filter is used in the air intake of a gats turbine [0058] The fingers 22 can be affixed to the connection plates 1813, 1823 by any suitable means. For example, the end of a finger that extends through the connection plate can have a screw portion to attach to a nut that can be tightened against the connection plate.

[0059] Other aspects, embodiments and modifications 100601 In the preceding embodiments, the support structure 2 has been described with two connection members 21. Different numbers of connection members 21 can be used with a corresponding number of connection plates 1813, 1823 in the filter frame 18. For example, when a support structure 2 includes only one connection member 21, the corresponding filter frame 18 need only include one connection plate 1813, 1823. Similarly, when a support structure 2 includes three connection members 21, the corresponding filter frame 18 will include three connection plates 1813, 1823 The distance between the sheets of filter material 1412 151 at the apex of the filter 1 will still be smaller than the distance between the sheets of filter material 141, 151 at the connection plates 1813, 1823 irrespective of the number of connection plates.

100611 In some embodiments, the connection plates are not in contact with the side panels 181, 182. For example, the first connection plate 1813 may be between the first side panel 181 and the second side panel 182, but not connected to either side panel. In such an arrangement, connection plates 1813, 1823 may include connection plate support walls extending from the connection plate 1813, 1823 to the end piece 16, and extending between the first face and the second face 141, 151. The fingers 22 of the support structure 2 therefore need not attach to the filter 1 at the corners, and additional filter material can be used.

100621 Many other variants and embodiments will be apparent to the skilled reader, all of which are intended to fall within the scope of the invention whether or not covered by the claims as filed. Protection is sought for any and all novel subject matter and combinations thereof disclosed herein.

Claims

Claims 1 A filter, comprising: a closed end, an open end opposed to the closed end, a first face extending between the closed end and the open end, a second face opposite the first face, the second face extending between the closed end and the open end, wherein the first face and the second face are closer at the closed end than at the open end, at least one connection plate extending from the first face to the second face and being operable to connect to a support frame that has connection members that extend through the filter from the open end, wherein a distance between the open end and the connection plate is less than a distance between the open end and the closed end.
2. A filter of claim 1, further comprising a first sheet of filter material associated with the first face and a second sheet of filter material associated with the second face, wherein the first and second sheet of filter material are closer at the closed end than at the connection plate.
3. A filter of claim 2, wherein the first sheet of filter material and the second sheet of filter material are in physical contact at the closed end.
4. A filter claim 2 or claim 3, wherein the sheets of filter material are pleat packs.
5. A filter of claim 1, wherein the filter comprises an end plate parallel to the at least one connection plate, the end panel being at the closed end.
6. A filter of any preceding claim, wherein the at least one connection plate consists of two connection plates.
7. A filter of any preceding claim, comprising a filter frame haying a flange at the open end, and first side panel and a second side panel, wherein the first side panel and the second side panel are both in contact with the first face and the second face, and wherein the first side panel and the second side panel taper from a widest point at the flange toward a narrowest point at the closed end.
8. A filter of claim 7, wherein the first side panel includes a main portion and a closed end portion, the closed end portion being closer to the closed end than the main portion and is offset from the main portion toward the second side panel, and wherein the second side panel includes a main portion and a closed end portion, the closed end portion being closer to the closed end than the main portion and is offset from the main portion toward the first side panel
9. A filter of claim 7 or claim 8, wherein the at least one connection plate consists of a connection plate in contact with the first side panel and another connection plate in contact with the second side panel.
10. A filter system comprising a filter of any preceding claim and a support frame, the support frame comprises a base plate having a hole therethrough and at least one connection means, wherein the base plate is located at the open end of the filter and wherein the at least one connection members connects to the at least one connection plate.