Integrally supported improved pulse filter

Abstract

The filter element includes a filter media tube, a first end cap, and a second end cap. The filter media tube extends between the first end and the second end. The filter media tube has a cylindrical periphery and defines a central cavity. A first end cap is secured to a first end of the filter media tube. The first end cap includes a first aperture having a first diameter. A second end cap is secured to the second end of the filter media tube. The second end cap includes an attachment region adjacent the second end of the filter media and a first central hub located radially inward of the attachment region. The first central hub defines a second aperture having a second diameter. The second diameter is smaller than the first diameter. A system having one or more filter elements, a tubesheet, and a mounting yoke is provided.

Description

Technical Field

[0001] The present invention relates generally to filter elements for filtering air and, more particularly, to filter elements for filtering air for use with a gas turbine filter system. Background Art

[0002] Systems such as gas turbines have a filter system in the form of a filter housing with a large number of filter elements mounted to a tube sheet by corresponding mounting yokes. The filter element may be "self-cleaning", i.e. it may be cleaned in situ periodically by a pulse of compressed air from the downstream (cleaning) side, which briefly reverses the flow through the pulse filter. A large number of pulse filters in a filter housing typically has hundreds of filter elements, which need to be replaced periodically.

[0003] The traditional geometry of filter elements for such applications is to have a conical element downstream of a cylindrical element. In this way, the conical element is axially located between the tube sheet and the cylindrical element. However, it is also known to have an inverted geometry, i.e., the positions of the conical element and the cylindrical element are reversed, with the conical element being located upstream of the cylindrical element, as shown in U.S. Patent Publication No. 2015 / 0082758. In order to accommodate this inverted geometry, the diameter of the cylindrical element is increased to match the diameter of the larger diameter end of the conical element. This inverted geometry can provide a larger filtration area in the same physical space and improve the flow distribution along the length of the filter element, resulting in a reduced initial pressure loss for a given flow rate and improved filter life.

[0004] The mounting yoke to which these pulse filters may be mounted is generally in the form of a tripod comprising three legs fixed to the tube sheet or housing wall. The mounting yoke and conical filter element are sized so that the weight of the latter is supported by the former until the cylindrical element is mounted and the two elements are secured together with a nut or other securing means at the upstream end of the pulse filter.

[0005] When the configuration is reversed, with the conical element upstream of the cylindrical element, the larger diameter cylindrical element must be fitted onto the mounting yoke first. Due to the constant diameter of the cylindrical element, the end of the cylindrical element farthest from the tube sheet may not be well supported on the tripod-shaped mounting yoke with straight legs. Therefore, while the inverted geometry results in improved performance, it also potentially results in increased time and cost for the operator to install the filter. In addition, any sealing gasket on the downstream end of the filter element may not properly seat against the tube sheet in the filter housing because the sealing gasket often tilts relative to the sealing surface of the tube sheet when the conical filter element is fitted and the conical filter element is quickly secured against the cylindrical filter element, resulting in air bypass.

[0006] Known prior art includes US Patent Publication No. 2015 / 0082758 which is directed to a similar pulse filter design, and US Patent Publication No. 8888884 which is directed to an adapter for use between an end of a filter element and a filter housing.

[0007] Other known prior arts include US Patent Publication 2004 / 0103626, US Patent No. 7585343, US Patent Publication 2008 / 0229927, US Patent No. 8715384, US Patent Publication 2008 / 0092501, US Patent No. 8673040, US Patent No. 8721756 and PCT Patent Application Publication WO2010144012.

[0008] The present invention provides an improvement over the prior art as it relates to filter elements and, more particularly, filter element assemblies incorporating conical filter elements stacked axially with cylindrical filter elements within a filter housing filter system. Summary of the invention

[0009] Examples include new and improved filter elements, filter element assemblies, and filter systems. Specifically, examples include new and improved filter elements, filter element assemblies, and filter systems that include integrated structure in one or more filter elements for positioning the filter element relative to a mounting yoke of the filter system for mounting the one or more filter elements relative to a tube sheet.

[0010] In one example, a filter element is provided that includes a filter media tube, a first end cap, and a second end cap. The filter media tube extends between a first end and a second end. The filter media tube has a cylindrical outer periphery and defines a central cavity. The first end cap is secured to the first end of the filter media tube. The first end cap includes a first orifice having a first diameter. The second end cap is secured to the second end of the filter media tube. The second end cap includes an attachment area adjacent to the second end of the filter media and a first center hub positioned radially inwardly relative to the attachment area. The first center hub defines a second orifice having a second diameter. The second diameter is smaller than the first diameter.

[0011] Optionally, at least one flow aperture is formed through the second end cap radially between the first central hub and the attachment area.

[0012] Optionally, the first central hub is attached to the attachment area by at least one spoke extending radially between the first central hub and the attachment area.

[0013] Optionally, the first central hub is attached to the attachment region via an annular region having a plurality of fluid flow perforations.

[0014] Optionally, the attachment area is an annular non-perforated area forming an annular well that receives the second end of the filter media tube.

[0015] Optionally, the attachment area has a radially outer annular sidewall, a radially inner annular sidewall, and a bottom wall extending radially therebetween. The second end of the filter media tube is axially received between the radially inner sidewall and the outer sidewall.

[0016] Optionally, the filter media tube has an outer radius defined by the outer periphery and an inner radius defined by the inner periphery. The filter media tube has a filter media thickness defined between the outer radius and the inner radius. The periphery of the second aperture is radially spaced inwardly from the inner periphery of the filter media tube by a distance that is at least 50% of the filter media thickness at the second end.

[0017] Optionally, the second end cap includes a connection region connecting the attachment region to the first central hub.

[0018] Optionally, the connection area is provided by a nozzle extending axially toward the first end. The outlet end of the nozzle provides the second orifice. The outlet end is axially positioned between the first end and the second end of the filter medium tube.

[0019] Optionally, the nozzle includes a curved surface extending between the attachment area and the first central hub. When moving from the attachment area to the first central hub, the curved surface extends radially inward and axially toward the first end of the filter media tube so that the diameter of the nozzle decreases when moving from the attachment area to the second central hub.

[0020] Optionally, the second end cap comprises at least one guide vane attaching the first central hub to the attachment area.

[0021] Optionally, at least one guide vane is positioned radially between the attachment area and the first central hub.

[0022] Optionally, a second central hub is provided. The second central hub is axially spaced apart from the first central hub and away from the first end of the filter medium tube. The second central hub includes a third central orifice having a third diameter. The third diameter is smaller than the first diameter and the second diameter.

[0023] Optionally, the second central hub is connected to at least one guide vane. The at least one guide vane axially connects the first central hub to the second central hub.

[0024] Optionally, the filter media tube defines a central axis extending axially between a first end and a second end. At least one guide vane has a first vane end proximate the attachment area and a second vane end axially spaced from the first vane end toward the first end of the filter media tube. The first and second vane ends are angularly offset from each other around / about the central axis.

[0025] Optionally, at least one guide vane extends axially toward the first end cap. At least one guide vane has a radially inner edge that contracts radially outwardly when moving axially toward the first end cap.

[0026] Optionally, at least one guide vane is a spiral vane.

[0027] Optionally, the at least one guide vane is configured to impart an angular component about / with respect to a central axis of the filter media tube to the fluid flow within the central cavity.

[0028] Optionally, the second end cap is an end disc formed from sheet metal.

[0029] Optionally, the second diameter is at least 25%, more preferably at least 40%, of the outer diameter of the filter media tube.

[0030] Optionally, the first central hub defines a mounting yoke locating surface. The mounting yoke locating surface faces radially inwardly. The mounting yoke locating surface at least partially defines the second aperture.

[0031] In one example, a filter element assembly is provided, which includes a first filter element as described above and a conical filter element. The conical filter element is axially aligned with the first filter element in operation. The conical filter element includes a conical section of filter media extending between a third end and a fourth end. The conical section of the filter media defines a second central cavity. In operation, the second central cavity is in fluid communication with the first central cavity of the first filter element. The outer diameter of the third end is greater than the outer diameter of the fourth end. The outer diameter of the second end of the filter media tube of the first filter element is substantially equal to the outer diameter of the third end of the conical section of the filter media of the conical filter element.

[0032] Optionally, the outer diameter of the second end of the filter media tube of the first filter element is plus or minus 10% of the outer diameter of the third end of the tapered section of the filter media of the tapered filter element.

[0033] Optionally, the conical filter element comprises a third end cap fixed to a third end of the conical section of the filter medium. The third end cap comprises a fourth aperture having a fourth diameter. The fourth diameter is greater than the second diameter.

[0034] Optionally, the fourth diameter is substantially equal to the first diameter of the first end cap of the first filter element.

[0035] Optionally, the first end cap is substantially identical to the third end cap.

[0036] Optionally, the fourth diameter is substantially equal to the second diameter of the second end cap of the first filter element.

[0037] Optionally, the second end cap is substantially identical to the third end cap.

[0038] In one example, a filter system is provided. The filter system includes a filter element assembly according to any of the above embodiments or examples, a tube sheet, and a mounting yoke. The tube sheet defines a flow orifice. The mounting yoke includes a plurality of legs that contract toward each other when moved away from the tube sheet.

[0039] Optionally, the plurality of legs of the mounting yoke include a first leg and a second leg. Each leg includes a first end and a second end. The first end is connected to the tube sheet in a spaced relationship from one another. The second end of the first leg is connected to the second end of the second leg so that when moving / transitioning away from the tube sheet toward the second end, the first leg and the second leg contract toward each other. The first center hub is sized to position the second end cap of the first filter element relative to the first leg and the second leg when the filter element assembly is mounted to the mounting yoke.

[0040] Optionally, the conical filter element has a fourth end cap secured to a fourth end thereof, the fourth end cap having a non-perforated region enclosing a fourth end of the conical section of the filter medium, the non-perforated region having a mounting hole extending therethrough. A mounting shank of the mounting yoke extends through the mounting hole. A fastener attached to the mounting shank secures the filter element assembly axially to the mounting yoke and in axial abutment with the tube sheet, while the first aperture of the first end cap of the filter element is in fluid communication with the flow aperture of the tube sheet.

[0041] Optionally, a tube sheet seal seals the first end cap of the first filter element to the tube sheet.

[0042] Optionally, the filter element assembly seal seals the first filter element to the conical filter element.The first filter element and the conical filter element are separate components that are not permanently fixed to each other.

[0043] Optionally, the first central hub radially engages at least one of the first leg and the second leg of the mounting yoke. In a more specific example, the first central hub radially engages all legs of the mounting yoke.

[0044] Optionally, the first central hub radially engages both the first leg and the second leg.

[0045] Optionally, the mounting yoke is a tripod including a third leg having a first end and a second end. The first end is secured to the tube sheet in a spaced relationship from the first ends of the first and second legs, and the second end is secured to the second ends of the first and second legs. The first center hub is sized to position the second end cap of the first filter element relative to the first, second and third legs when the filter element assembly is mounted to the mounting yoke.

[0046] Optionally, the conical filter element includes a third end cap fixed to the third end of the conical filter medium. The third end cap has a third aperture. When the filter assembly is mounted on the mounting yoke, the third aperture of the third end cap of the conical filter element is not radially positioned by the mounting yoke.

[0047] Optionally, the conical filter element includes a third end cap fixed to the third end of the conical filter medium. The third end cap has a third aperture. When the filter assembly is mounted on the mounting yoke, the third aperture of the third end cap of the conical filter element is positioned by the mounting yoke.

[0048] Optionally, the third end cap of the conical filter element is substantially identical to the first end cap of the cylindrical filter element.

[0049] In one example, a method of mounting a filter element assembly to a tube sheet and a mounting yoke is provided. The tube sheet defines a flow orifice. The mounting yoke extends outward from the tube sheet. The mounting yoke includes a first leg and a second leg. The legs contract toward each other when moving / transitioning away from the tube sheet. The method includes mounting a first filter element to the mounting yoke in a manner such that a first center hub is located on the mounting yoke and a first end of the first filter element is axially located between the tube sheet and a second end of the first filter element. After mounting the first filter element, the method includes mounting a conical filter element to the mounting yoke and positioning the conical filter element axially against a second end cap of the first filter element.

[0050] Optionally, the method includes axially compressing a first seal between a first end cap of the filter element and the tube sheet. The method includes axially compressing a second seal between a second end cap of the filter element and the first end cap of the conical filter element. The method includes securing the first filter element and the conical filter element to a mounting yoke using a fastener. The fastener provides axial compression.

[0051] Optionally, a filter element for a gas turbine having a mounting yoke is provided. The filter element includes a conical element and a cylindrical element, each element having opposite (or opposing) faces. An annular intermediate disk is located between the opposite faces of the conical element and the cylindrical element. The conical element, the cylindrical element and the intermediate disk are fixed together. When the filter element is assembled on the gas turbine, the annular intermediate disk is supported on the mounting yoke.

[0052] Optionally, the annular intermediate disk includes structure having one or more apertures to allow air to flow through the length of the filter element.

[0053] Optionally, the annular intermediate disk has aerodynamic means configured to change the flow distribution within the filter element.

[0054] Optionally, the aerodynamic device has a configuration selected from the group consisting of one or more guide vanes or nozzles.

[0055] In one example, a mounting yoke having a longitudinal axis is provided for supporting a filter element in a gas turbine. The mounting yoke includes one or more support structures extending along the longitudinal axis. An annular intermediate disk is supported by the support structure along the longitudinal axis. The annular intermediate disk is configured to receive and support the filter element. The intermediate disk is fixed along the longitudinal axis of the mounting yoke and supports the filter element when the filter element is assembled on the mounting yoke.

[0056] Other aspects, objects and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The accompanying drawings, which are incorporated in and form a part of the specification, illustrate several aspects of the present invention and together with the description serve to explain the principles of the invention. In the drawings:

[0058] Figure 1 is a perspective view of at least a portion of a filter system according to an example;

[0059] Figure 2 yes Figure 1 an exploded view of a portion of the illustrated filter system showing the filter element assembly and its tube sheet removed from the mounting yoke;

[0060] Figure 3 is a cross-sectional view of a filter element assembly mounted to a mounting yoke of a filter system;

[0061] Figure 4 yes Figure 1 A perspective and partially assembled view of a filter assembly of a filter system;

[0062] Figure 5 is a cross-sectional view of a filter element assembly of a filter system;

[0063] Figure 6 is an exploded view of a cylindrical filter element of a filter element assembly;

[0064] Figure 7 yes Figure 6 a cross-sectional view of a second end cap of a cylindrical filter element;

[0065] Figure 8 showing a cylindrical filter element mounted to a mounting yoke of a filter system with a tapered cone of the filter element assembly removed;

[0066] Figure 9-11 is an alternative embodiment of an end cap for use with a cylindrical filter element according to an example;

[0067] Fig.12 is a partial illustration of an alternative end cap for a cylindrical filter element mounted to a mounting yoke of a filter system, wherein the end cap includes a spiral blade

[0068] Fig.13 yes Fig.12 A cross-sectional view of the end cap and mounting yoke;

[0069] Fig.14 yes Fig.12 A front view of an end cap;

[0070] Fig.15 yes Fig.12 The end caps and Fig.14 Relative rear view;

[0071] Fig.16 and 17 yes Fig.12 A perspective view of an end cap;

[0072] Fig.18 is a partial illustration of an alternative end cap for a cylindrical filter element mounted to a mounting yoke of a filter system, wherein the end cap includes a nozzle;

[0073] Fig.19 yes Fig.18 A cross-sectional view of the end cap and mounting yoke;

[0074] Fig. 20 and 21 yes Fig.18 A cross-sectional view of an end cap;

[0075] Fig. 22 is a partial illustration of an alternative end cap for a cylindrical filter element mounted to a mounting yoke of a filter system, wherein the end cap includes an alternative form of a nozzle;

[0076] Fig.23 is used Fig. 22 A cross-sectional view of a cylindrical filter element with an end cap mounted to a mounting yoke of a filter system;

[0077] Fig.24 and 25 yes Fig. 22 a cross-sectional view of an end cap; and

[0078] Fig.26 yes Fig. 22 A perspective view of the end cap.

[0079] While the invention will be described in conjunction with certain preferred embodiments, it is not intended to be limited to those embodiments. On the contrary, the intention is to cover all alternatives, modifications and equivalents included within the spirit and scope of the invention as defined by the appended claims. DETAILED DESCRIPTION

[0080] Figure 1 A filter system 100 is shown, and more particularly an air filter system for filtering air for a gas turbine. Although the present filter system is particularly suitable for use in an air filter system for a gas turbine, the filter system 100 and its components may be used in other filter systems for filtering fluids other than air, and in filter systems for filtering fluids for other downstream systems other than gas turbines.

[0081] The filter system 100 generally includes a tube sheet 102 and a plurality of filter element assemblies 104 mounted thereon. The plurality of filter element assemblies 104 are arranged in an array. In some filter systems 100, more than 100 filter assemblies 104 may be mounted to the tube sheet 102.

[0082] In the filter system 100, an optional reverse pulse cleaning system 106 is provided. The reverse pulse cleaning system 106 blows air through the filter element assembly 104 from a downstream location in a direction opposite to that during normal filtering operation to remove impurities from the filter element assembly that have been separated from the fluid flowing through the filter element assembly 104 during normal operation.

[0083] Generally, the tube sheet 102 is oriented vertically, and each filter element assembly 104 is mounted in a suspended orientation. The tube sheet 102 provides a flow aperture 110 adjacent each filter assembly 104. The fluid to be filtered will flow through each filter element assembly (radially in the example shown) and then through the associated flow aperture 110.

[0084] A mounting yoke 112 positioned adjacent each flow aperture 110 secures the filter element assembly 104 against the tube sheet 102 and supports the filter element assembly 104 in a suspended orientation.

[0085] Additional references Figure 2 and Figure 3 , in this example, the mounting yoke 112 is in the form of a tripod having three longitudinally extending legs 114. Each leg 114 extends between a first end 115 and a second end 116. The first end 115 is operatively secured to the tube sheet 102 (in this example by screws 119). The second ends 116 are secured to each other by mounting studs 118. In this example, the legs 114 converge toward each other when moving / transitioning axially away from the tube sheet 102 and toward the interconnected second ends 116.

[0086] Tube sheet seal 122 operatively seals filter element assembly 104 to upstream face 124 of tube sheet 102 to prevent fluid bypass between filter element assembly 140 and tube sheet 102, forcing dirty fluid to flow through the filter element assembly before flowing downstream.

[0087] In this example, mounting stud 118 is a threaded stud that receives a fastener 126 for securing filter element assembly 104 to mounting yoke 112. The fastener may axially press filter element assembly 104 against tube sheet 102 and, in particular, tube sheet seal 122.

[0088] Reference Figure 3-5, in this example, the filter element assembly 104 includes first and second filter elements in the form of a cylindrical filter element 130 and a conical filter element 132. The cylindrical filter element 130 includes a filter media tube 133 defining a central cavity 134, which is in operative fluid communication with a central cavity 136 of a conical section of filter media 137 of the conical filter element 132. In the example shown, the filtered fluid flow 138 flows radially through the filter media 133, 137, and then flows axially within the central cavities 134, 136, and then flows out through the flow apertures 110 of the tube sheet 102 (see Figure 3 ).

[0089] Reference Figure 6 The filter media tube 133 of the cylindrical filter element 130 extends axially between a first end 140 and a second end 142. First and second end caps in the form of first and second end discs 144, 146 are operatively secured to the first and second ends 140, 142 of the filter media tube 133.

[0090] In this example, each end disc 144, 146 has an attachment area 147, 149, which is shown in the form of a bottom annular wall portion, which partially defines an annular well 148, 150 that receives the corresponding end 140, 142 of the filter medium tube 133. An adhesive such as plastisol or urethane can be used to secure the end disc 144, 146 to the filter medium tube 133. The annular well 148, 150 has an axially extending annular side wall and a radially connecting bottom wall extending radially between the inner and outer annular side walls.

[0091] The first end disk 144 defines a first aperture 152 that provides an outlet aperture for the filter element assembly 104 through which filtered air exits the filter element assembly and passes through the tube sheet flow aperture 110. In this example, the first aperture 152 is provided by the radially innermost portion of the annular well 148, such as by a radially inner, axially extending annular sidewall.

[0092] Reference Figure 4-7 The second end disc 146 includes a first central hub 154 that defines a second aperture 156 through which filtered fluid that has passed through the filter media 137 enters the central cavity 134 before exiting the filter element assembly 104 .

[0093] In this example, the first central hub 154 is provided by an axially extending sidewall 158 that is operatively connected to the attachment area 149 of the second end disk 146, i.e., the second annular well 150. In this example, a plurality of spokes 160 extend radially between the radially innermost annular sidewall 161 and the first central hub 154. Intermediate flow passages 162 are formed between the spokes 160. Thus, the spokes 160 provide a connection portion extending between the first central hub 154 and the attachment area of ​​the second end cap 146.

[0094] Reference Figure 8 , the first central hub 154 is used to locate the second end of the cylindrical filter element 130 when mounted to the mounting yoke 112. More specifically and with additional reference to Figure 6 , the filter media tube 133 filter element has a substantially constant inner diameter D1 and outer diameter D2 along its entire axial length. In addition, the first aperture 152 has a diameter D3 that is sized to allow the mounting yoke 112 to pass through and be received so that the cylindrical filter element 130 can be sealed against the tube sheet 102. In addition, the diameter D3 is preferably sized so that the size of the first end disc 144 closely matches the size of the imaginary circular perimeter defined by the legs 114 of the mounting yoke 112 to properly align the first end disc 44 with the tube sheet 102 during assembly.

[0095] However, since the mounting yoke 112 is generally in the form of a tripod or at least in the form of a conical support structure (the conical support structure defines an imaginary circular perimeter but with a reduced diameter as it moves / transitions axially away from the tube sheet 102), the second end disc 146 incorporates a first central hub 154 for locating the second end of the conical filter element 130 during installation. In this example, the diameter D4 of the second orifice 156 provided by the central hub 154 is smaller than the diameter D3. In addition, when the cylindrical filter element has been installed on the mounting yoke 112 but the conical filter element 132 has not yet been installed (particularly before the fasteners 118 are installed), the smaller diameter D4 allows the first central hub 154 to locate the second end of the cylindrical filter element 130. The addition of the first central hub 154 prevents the second end of the conical filter element 130 from pivoting and tilting toward the legs 114 of the mounting yoke 112 under the action of gravity (this is caused by the reduced perimeter defined by the contracted configuration of the legs).

[0096] Figure 8 The first central hub 154 is shown positioned relative to the legs 114 of the mounting yoke 112 prior to installation of the conical filter element 132 , but with the cylindrical filter element 130 against the tube sheet 102 .

[0097] Reference Figure 3 and Figure 5, the conical filter element 132 includes first and second end discs 170, 172 attached to opposite first and second ends 174, 176 of the conical section of the filter medium 137. The first and second end discs 170, 172 include annular wells 178, 180 receiving the ends (portions) 174, 176, respectively. The first end disc 170 defines an orifice 182 that fluidly connects the central cavity 136 to the central cavity 134 via the orifice 156.

[0098] The second end disc 172 has a substantially non-perforated area 184 that spans the open second end 176 of the tapered section of the filter media 137. The non-perforated area 184 includes a central mounting aperture 186 that receives the mounting stud 118 of the mounting yoke 112.

[0099] In some preferred but optional embodiments, first end disc 170 of conical filter element 132 is identical to first end disc 144 of cylindrical filter element 130 .

[0100] In other examples, the first end disc 170 is substantially the same as or similar to the second end disc 146 of the cylindrical filter element 130. In such an arrangement, the first end disc 170 would then have a central hub similar to the central hub 154, which would help locate that end of the conical filter element 132 during installation.

[0101] The filter assembly seal 188 is disposed between the second end disk 146 of the cylindrical filter element 130 and the first end disk 170 of the conical filter element 132. When the filter assembly 104 is mounted to the mounting yoke 112, compression of the filter element assembly 104 by the fasteners 126 also compresses the filter assembly seal 188 between the cylindrical filter element 130 and the conical filter element 132, forming a seal between the two filter elements 130 and 132.

[0102] In a preferred embodiment, the distance D5 between the inner periphery of the filter media tube 133 and the radially inward positioning surface 190 of the first central hub 154 is at least 50% (e.g., (diameter D1-D2) / 2) of the radial thickness T of the filter media tube. In the illustrated embodiment, the distance D5 is about 90% of the radial thickness T or more.

[0103] In one embodiment, a distance D5 between the inner periphery of filter media tube 133 and radially inward positioning surface 190 of first central hub 154 is no greater than 25% of the filter media tube inner diameter D2 (ie, no greater than 50% of the inner radius of filter media tube 133).

[0104] If this is applied to a conical filter element, these dimensions are considered at the axial position where the central hub is located relative to the axial length of the filter media of the conical filter element.

[0105] In some examples, the first and second end discs 144, 146 are formed of stamped metal, such as stamped sheet metal. However, other embodiments may employ other materials such as molded plastics. Furthermore, in other examples, the end caps need not include wells, and the end caps may be secured to the filter media in other ways, such as by embedding the ends of a segment of the filter media into an attachment area of ​​the end caps. In some examples, the end caps may be formed in situ, rather than being preformed and then subsequently secured to the segment of the filter media.

[0106] The inclusion of openings 162 in second end disk 146 reduces flow restriction between conical filter element 132 and cylindrical filter element 130 .

[0107] Figure 9-11 Additional embodiments of second end discs 246, 346, 446 are shown. Although filter media is not shown, a filter media tube similar to filter media tube 133 and a first end disc similar to first end disc 144 can be provided in combination with second end discs 246, 346, 446 to form a corresponding cylindrical filter element.

[0108] Fig. 9 Another embodiment of a second end disc 246 is shown. The second end disc 246 is substantially similar to the second end disc 146. However, rather than using spokes 160, a connection extending between the first central hub 254 and the attachment region 247 is provided by an annular region 261 that includes a plurality of perforations 162 that help reduce flow restriction.

[0109] Fig.10 Another embodiment of a second end disc 346 is shown having a connection portion provided by an annular region 361. In this embodiment, the connection portion is completely non-perforated between the first central hub 354 and the attachment region 347. While this design provides greater resistance, it can still function to allow positioning of a cylindrical filter element on a retracted mounting yoke.

[0110] Fig.11 Another embodiment of a second end disc 446 is shown that includes fewer flow apertures 462 than the first embodiment of the second end disc 146 .

[0111] Figure 12-17Another embodiment of a second end disc 546 is shown removed from the remainder of the cylindrical filter element but mounted to the mounting yoke 112. In this embodiment, the second end disc 546 includes an attachment area 547 similar to the attachment area 147. Although the filter media is not shown, a filter media tube similar to the filter media tube 133 and a first end disc similar to the first end disc 144 can be provided in combination with the second end disc 546 to form a corresponding cylindrical filter element.

[0112] The end disk 546 includes a plurality of guide vanes in the form of spiral blades 592 to impart swirl to the clean fluid flow within the central cavity of the filter element assembly, which results in a change in the radial pressure distribution at the filter discharge plane. The selection of parameters such as the pitch and number of spiral blades 592 can reduce the total pressure loss through the filter element and the tube sheet 102. The guide vanes can impart an angular flow component around the central axis of the filter element assembly to the clean fluid flow within the filter element assembly.

[0113] The spiral blade 592 extends axially from a first end 593 to a second end 594. The first end 593 is positioned near the first end of the filter media tube (not shown), i.e., toward the tube sheet 102, and the second end 594 is positioned near the second end of the filter media tube (not shown), i.e., toward the thread stud 118. The second end 594 is connected to the attachment area 547. The first end 593 is connected to the first central hub 554. Thus, the spiral blade 592 connects the attachment area 547 to the first central hub 554.

[0114] The first central hub 554 has an aperture 556 that is sized and configured to position the second end disc 546 on an imaginary periphery defined by the legs 114 of the mounting yoke 112. In this example, the first central hub 554 is positioned at an axial position along the mounting yoke 112 that is axially closer to the tube sheet 102.

[0115] The first central hub 554 provides stability to the spiral blade 592 and maintains the angular spacing of the first end 593. The first central hub is shown attached proximate the first end 593 near the radially inner edge 598 of the spiral blade 592.

[0116] The first central hub 554 has a first radius R1 (see Fig.15 ).

[0117] The second center hub 595 is attached to the radially inner edge of the spiral blade 592 near the second end 594. The second center hub 595 can be configured to be radially positioned on the outer periphery of the leg 114. In some embodiments, the first center hub 554 is not configured to be positioned on the outer periphery of the leg 114, and only the second center hub 595 is positioned on the foot 114. In other embodiments, only the first center hub 554 is radially positioned on the outer periphery of the leg 114.

[0118] Reference Fig.15 , the second center hub 595 has a second inner radius R2. The second inner radius R2 is smaller than the first inner radius R1. The smaller radius R2 only needs to be suitable for the portion of the mounting yoke 112 that defines the smaller imaginary outer periphery.

[0119] The first end 593 of the spiral blade 592 is angularly offset about the central axis 596 of the second end disk 546. In addition, in this example, when axially moving / transitioning between the first end 593 and the second end 594, each spiral blade twists about the axis extending between the first and second ends 593, 594, thereby providing a spiral shape.

[0120] The spiral blades 592 are configured to spin the filtered fluid exiting the conical filter element and flowing into the corresponding cylindrical filter element to help reduce air flow pressure drop.

[0121] When moving / transitioning from the second end 594 toward the first end 593, the radially inner edge 598 of the spiral blade 592 contracts radially outward. This prevents interference between the spiral blade 592 and the leg 114 during installation. This also corresponds to the relationship that the radius R1 is greater than the radius R2.

[0122] In the example shown, the radially outer edge 599 of the spiral blade maintains a substantially constant radial distance from the central axis 596 when moving / transitioning from the second end 594 to the first end 593 .

[0123] In this example, the first central hub 554 for positioning the second end disc 546 on the mounting yoke 112 will be axially located within the central cavity of the filter media and will be axially positioned between the first and second ends of the filter media tube (e.g., filter media tube 133 and ends 140, 142).

[0124] The flow apertures 562 are formed between the second central hub 595 and the attachment area 547 and the adjacent spiral blades 592. The spiral blades 592 act as spokes extending radially between the second central hub 595 and the attachment area 547.

[0125] As used herein, a spiral blade 592 may have a flat surface or may have a curved surface.

[0126] Figure 18-21 Another example of a second end disc 646 for use with a conical filter element is shown. Although the filter media is not shown, a filter media tube similar to the filter media tube 133 and a first end disc similar to the first end disc 144 can be provided in combination with the second end disc 646 to form a corresponding cylindrical filter element.

[0127] In this example, a connecting portion 667 extending between the attachment area 647 and the first central hub 654 forms the nozzle 656 .

[0128] This configuration including nozzle 656 increases the portion of flow through the upstream conical filter element.Nozzle 656 can also reduce pressure losses across the filter element assembly for a given flow rate of fluid flow through the filter element assembly.

[0129] The outlet end of the nozzle 656 provides a first central hub 654 that positions the cylindrical filter element on the periphery of the leg 114 .

[0130] Reference Fig. 20 , when the connecting portion 667 moves / transitions from the attachment area 647 toward the outlet end (e.g., the first central hub 654), the connecting portion 667 extends radially inward and axially toward the first end of the corresponding filter element (e.g., toward the tube sheet). In addition, the connecting portion 667 is a generally arcuate annular sidewall. In this example, the connecting portion 667 has a circular cross-sectional shape. In other examples, the annular sidewall can have an oval or elliptical cross-sectional shape.

[0131] In this example, the connecting portion 667 is connected to the radially inner annular side wall of the portion forming the well 650 .

[0132] In this example, the first central hub 654 used to position the second end disc 646 on the mounting yoke 112 will be axially located within the central cavity of the filter media and will be axially positioned between the first and second ends of the filter media tube (e.g., filter media tube 133 and ends 140, 142).

[0133] Figure 22-26 A conical filter element 730 (see Fig.23 ) is another example of a second end plate 746 used in conjunction with the filter medium 733 and the first end plate 744. Fig.23 Shown in.

[0134] In this embodiment, an alternative form of nozzle 756 is formed upstream of the first central hub 754. In addition, the first central hub 754 is configured to radially position the second end pa 746 relative to the outer periphery of the leg 114.

[0135] A plurality of spokes 761 extend radially between the attachment area 747 and the nozzle 756 and its first central hub 754. A plurality of flow orifices 762 are disposed between the spokes 761, the outer periphery of the nozzle 756, and the attachment area 747.

[0136] In this example, the first end 771 of the nozzle 756 is offset from the tube axis of the filter medium 733. When the corresponding filter element assembly is to be mounted to the mounting yoke 112, the nozzle 756 will be located in the central region of the conical filter element (e.g., the conical filter element 132). In other examples (not shown), the nozzle 756 can be located closer to the tube sheet 102. This may require appropriate changes in the diameter of the first central hub 754 to enable it to be positioned on the mounting yoke 112.

[0137] The nozzle 756 generally decreases in inner diameter when moving / transitioning axially from the first end 771 to the first central hub 754 .

[0138] This configuration including nozzle 756 increases the portion of flow through the upstream conical filter element.Nozzle 756 can also reduce pressure losses across the filter element assembly for a given flow rate of fluid flow through the filter element assembly.

[0139] The spiral blades 592 and nozzles 656, 756 are aerodynamic devices that can affect the amount and distribution of the pulsed cleaning flow, potentially increasing the entrainment rate into the pulse jet and through the tube sheet by accelerating the flow within the filter element. The size and shape of the aerodynamic devices are configured so that they are compatible with an end disc designed to fit around a mounting yoke.

[0140] In one example, the aperture provided by the center hub on the mounting yoke 112 does not carry or provide a radial seal. For example, an elastomer or felt gasket is not adjacent to the hole through the center hub to provide a direct seal radially inward.

[0141] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0142] In the context of describing the present invention (especially in the context of the following claims), the use of the terms "one", "an" and "the" as references should be interpreted as covering the singular and plural, unless otherwise specified herein or clearly contradicted by the context. Unless otherwise specified, the terms "include", "have", "include" and "include" should be interpreted as open terms (i.e., meaning "including but not limited to"). Unless otherwise specified herein, the reference to the value range herein is intended only as a shorthand method for individually citing each individual value falling within the range, and each individual value is incorporated into the specification as if it is individually quoted herein. Unless otherwise specified herein or clearly contradicted by the context, all methods described herein can be performed in any suitable order. The use of any and all examples or exemplary language provided herein (e.g., "such as") is only to better illustrate the present invention, and unless otherwise required, does not limit the scope of the present invention. Any language in the specification should not be interpreted as indicating that any undescribed element is essential to the practice of the present invention.

[0143] Preferred embodiments of the present invention are described herein, including the best mode known to the inventor for implementing the present invention. By reading the foregoing description, changes to these preferred embodiments may become apparent to those of ordinary skill in the art. The inventors expect that such changes will be appropriately adopted by those skilled in the art, and the inventors wish that the present invention be practiced in a manner different from that specifically described herein. Therefore, the present invention includes all modifications and equivalents to the subject matter described in the appended claims as permitted by applicable law. In addition, any combination of the above-mentioned elements in all possible variations thereof is included in the present invention, unless otherwise indicated herein or otherwise clearly contradictory in context.

Claims

1. A filter element, include: a filter media tube extending between a first end and a second end defining a central cavity, the filter media tube having a cylindrical outer periphery; a first end cap secured to a first end of the filter media tube, the first end cap including a first aperture having a first diameter; A second end cap is secured to the second end of the filter media tube, the second end cap comprising an attachment area adjacent the second end of the filter media and a first central hub radially positioned within the attachment area, the first central hub defining a second aperture having a second diameter, the second diameter being smaller than the first diameter.

2. The filter element according to claim 1, in, At least one flow aperture is formed through the second end cap radially between the first central hub and the attachment area.

3. The filter element according to any one of the preceding claims, in, The first central hub is attached to the attachment area by at least one spoke extending radially between the first central hub and the attachment area.

4. The filter element of claim 1 or 2, wherein the attachment region is an annular non-perforated area forming an annular well that receives the second end of the filter media tube.

5. A filter element according to any one of the preceding claims, wherein the attachment area has a radially outer annular sidewall, a radially inner annular sidewall, and a bottom wall extending radially therebetween, the second end of the filter media tube being axially received between the radially inner and outer sidewalls.

6. A filter element according to any preceding claim, in: The filter media tube has an outer radius defined by the outer periphery and an inner radius defined by the inner periphery, the filter media tube has a filter media thickness defined between the outer radius and the inner radius, and the periphery of the second aperture is radially spaced a distance from the inner periphery of the filter media tube that is at least 50% of the filter media thickness at the second end.

7. A filter element according to any preceding claim, wherein the second end cap comprises a connection region connecting the attachment region to the first central hub.

8. The filter element according to claim 7, in, The connection region is provided by a nozzle extending axially toward the first end, the outlet end of the nozzle providing the second orifice, the outlet end being axially positioned between the first and second ends of the filter media tube.

9. The filter element according to claim 8, in, The nozzle includes a curved surface extending between the attachment area and the first central hub, the curved surface extending radially inward and axially toward the first end of the filter media tube when transitioning from the attachment area to the first central hub so that the nozzle decreases in diameter when transitioning from the attachment area toward the first central hub.

10. The filter element of any one of claims 1, 2, and 4-6, wherein the second end cap includes at least one guide vane attaching the first central hub to the attachment area.

11. The filter element according to claim 10, in, The at least one guide vane is positioned radially between the attachment area and the first central hub.

12. The filter element according to claim 10 or 11 further includes a second center hub, which is axially spaced from the first center hub away from the first end of the filter medium tube, and the second center hub has a third center orifice, the third center orifice has a third diameter, and the third diameter is smaller than the first and second diameters.

13. The filter element of claim 12, wherein the second central hub is connected to the at least one guide vane, the at least one guide vane axially connecting the first central hub to the second central hub.

14. A filter element according to any one of claims 10 to 13, wherein the filter media tube defines a central axis extending axially between the first end and the second end, and the at least one guide vane has a first blade end proximate the attachment area and a second blade end axially spaced apart from the first blade end toward the first end of the filter media tube, and the first blade end and the second blade end are angularly offset from each other about the central axis.

15. The filter element according to any one of claims 10 to 14, in, The at least one guide vane extends axially toward the first end cap, and the at least one guide vane has a radially inner edge that contracts radially outward when axially transitioning toward the first end cap.

16. The filter element of any one of claims 10-15, wherein the at least one guide vane is a spiral vane.

17. The filter element of any one of claims 10-16, wherein the at least one guide vane is configured to impart an angular component about a central axis of the filter media tube to fluid flow within the central cavity.

18. A filter element according to any preceding claim, wherein the second end cap is an end disc formed from sheet metal.

19. The filter element of any one of the preceding claims, wherein the second diameter is at least 40% of the outer diameter of the filter media tube.

20. The filter element according to any one of the preceding claims, in, The first central hub defines a mounting yoke locating surface that faces radially inwardly and at least partially defines the second aperture.

21. A filter element assembly, include: A first filter element according to any preceding claim; and a conical filter element axially aligned with the first filter element, the conical filter element comprising: A tapered section of the filter medium extends between a third end and a fourth end, the tapered section of the filter medium defining a second central cavity, the second central cavity being in fluid communication with the first central cavity of the first filter element, the third end having an outer diameter greater than an outer diameter of the fourth end, the second end of the filter medium tube of the first filter element having an outer diameter substantially equal to an outer diameter of the third end of the tapered section of the filter medium of the tapered filter element.

22. The filter element assembly according to claim 21, in: The conical filter element includes a third end cap secured to a third end of the conical section of the filter media; The third end cap includes a fourth aperture having a fourth diameter that is greater than the second diameter.

23. The filter element assembly of claim 22, wherein the fourth diameter is substantially equal to a first diameter of a first end cap of the first filter element.

24. The filter element assembly of any one of claims 21 to 23, wherein the first end cap is substantially identical to the third end cap.

25. The filter element assembly of claim 22, wherein the fourth diameter is substantially equal to a second diameter of a second end cap of the first filter element.

26. The filter element assembly of claim 21, 22 or 25, wherein the second end cap is substantially identical to the third end cap.

27. A filter system, include: A filter element assembly according to any one of claims 21 to 26; a tube sheet defining a flow orifice; a mounting yoke including a first leg and a second leg, each leg having a first end and a second end, the first end being adjacent to the tube sheet and spaced apart from each other, the second end of the first leg being adjacent to the second end of the second leg, the first leg and the second leg converging toward each other when transitioning away from the tube sheet toward the second end; Wherein the first central hub is sized to position the second end cap of the first filter element relative to the first and second legs when the filter element assembly is mounted to the mounting yoke.

28. The filter system of claim 27, wherein the conical filter element has a fourth end cap secured to a fourth end thereof, the fourth end cap having a non-perforated region enclosing a fourth end of the conical section of filter media, the non-perforated region having a mounting aperture therethrough, the mounting shank of the mounting yoke extending through the mounting aperture; Also included is a fastener attached to the mounting shank to axially secure the filter element assembly to the mounting yoke and into axial abutment with the tube sheet, with the first aperture of the first end cap of the filter element in fluid communication with the flow aperture of the tube sheet.

29. The filter system of claim 27 or 28, further comprising a tube sheet seal sealing the first end cap of the first filter element to the tube sheet.

30. The filter system of any one of claims 27-29, further comprising a filter element assembly seal sealing the first filter element to the conical filter element.

31. The filter system of any one of claims 27-30, wherein the first central hub radially engages at least one of the first leg and the second leg.

32. The filter system of any one of claims 27-31, wherein the first central hub radially engages both the first leg and the second leg.

33. The filter system of any of claims 27-32, wherein the mounting yoke is a tripod, the tripod including a third leg having a first end and a second end, the first end being secured to the tube sheet in spaced relation to the first ends of the first and second legs, and the second end being secured to the second ends of the first and second legs; Wherein the first central hub is sized to position the second end cap of the first filter element relative to the first, second and third legs when the filter element assembly is mounted to the mounting yoke.

34. The filter system of any one of claims 27-33, wherein the conical filter element includes a third end cap secured to a third end of the conical filter media, the third end cap having a third orifice, and when the filter assembly is mounted to the mounting yoke, the third orifice of the third end cap of the conical filter element is not radially positioned by the mounting yoke.

35. The filter system of any one of claims 27-33, wherein the conical filter element includes a third end cap secured to a third end of the conical filter media, the third end cap having a third orifice, the third orifice of the third end cap of the conical filter element being radially positioned by the mounting yoke when the filter assembly is mounted to the mounting yoke.

36. The filter system of claim 35, wherein the third end cap of the conical filter element is substantially identical to the second end cap of the cylindrical filter element.

37. A method of mounting a filter element assembly to a tube sheet, the tube sheet defining a flow orifice and having a mounting yoke extending outwardly from the tube sheet, the mounting yoke comprising a first leg and a second leg, each leg having a first end and a second end spaced apart from each other adjacent the tube sheet, the second ends of the first leg and the second leg being adjacent to each other such that the first leg and the second leg converge toward each other when transitioning away from the tube sheet toward the second end, the method include: mounting the filter element of any one of claims 1-20 to the mounting yoke, wherein a first central hub is located on the mounting yoke and a first end of the first filter element is axially located between the tube sheet and a second end of the first filter element; and After the first filter element is installed, the conical filter element is mounted to the mounting yoke and axially abuts the second end cap of the first filter element.

38. The method according to claim 37, further comprising: include: axially compressing a first seal between a first end cap and a tube sheet of the filter element; and A second seal between the second end cap of the filter element and the third end cap of the conical filter element is axially compressed. The first filter element and the conical filter element are secured to the mounting yoke using fasteners that provide axial compression.

39. A filter element for a gas turbine having a mounting yoke, the filter element include: A first section and a second section; the first section having a top end disc attachable to the mounting yoke, and the second section having a bottom end disc having an annular opening positionable against a filter housing, thereby connecting the filter element to a flow orifice; The bottom end plate has an aerodynamic device circumscribing the annular opening; The aerodynamic device has a configuration that changes flow distribution within the filter element.

40. The filter element of claim 39, in, The aerodynamic device has a configuration selected from the group consisting of one or more propeller blades, nozzles or ejectors.

Images