WO2011000437A1 - Camflo gt wireframe - Google Patents

Camflo gt wireframe Download PDF

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Publication number
WO2011000437A1
WO2011000437A1 PCT/EP2009/058452 EP2009058452W WO2011000437A1 WO 2011000437 A1 WO2011000437 A1 WO 2011000437A1 EP 2009058452 W EP2009058452 W EP 2009058452W WO 2011000437 A1 WO2011000437 A1 WO 2011000437A1
Authority
WO
WIPO (PCT)
Prior art keywords
filter
pockets
filter unit
pocket
unit
Prior art date
Application number
PCT/EP2009/058452
Other languages
French (fr)
Inventor
Erik Lans
Original Assignee
Camfil Ab
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Camfil Ab filed Critical Camfil Ab
Priority to PCT/EP2009/058452 priority Critical patent/WO2011000437A1/en
Publication of WO2011000437A1 publication Critical patent/WO2011000437A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/02—Particle separators, e.g. dust precipitators, having hollow filters made of flexible material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/02—Particle separators, e.g. dust precipitators, having hollow filters made of flexible material
    • B01D46/023—Pockets filters, i.e. multiple bag filters mounted on a common frame
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/02—Particle separators, e.g. dust precipitators, having hollow filters made of flexible material
    • B01D46/04—Cleaning filters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/02—Particle separators, e.g. dust precipitators, having hollow filters made of flexible material
    • B01D46/06—Particle separators, e.g. dust precipitators, having hollow filters made of flexible material with means keeping the working surfaces flat
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/56—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with multiple filtering elements, characterised by their mutual disposition
    • B01D46/62—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with multiple filtering elements, characterised by their mutual disposition connected in series
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
    • F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
    • F02C7/04—Air intakes for gas-turbine plants or jet-propulsion plants
    • F02C7/05—Air intakes for gas-turbine plants or jet-propulsion plants having provisions for obviating the penetration of damaging objects or particles
    • F02C7/055—Air intakes for gas-turbine plants or jet-propulsion plants having provisions for obviating the penetration of damaging objects or particles with intake grids, screens or guards

Definitions

  • the present invention relates to a pocket filter assembly for removing particles from an air or gas flow
  • the pocket filter assembly may, for example, be provided in an air intake device for a gas turbine, such to prevent particles to enter the gas turbine.
  • Filters are often used to remove solid particles such as e.g. dust, pollen, mold, or sand from an air flow. Especially in applications where air quality is important, notably in building ventilation systems and in engines, filters are often indispensible for the provision of clean air.
  • gas turbines are generally operated with one or more filters for removing particles from an air or gas flow such that particles are hindered to enter the turbine.
  • potential damage risks such as e.g. turbine fouling, corrosion, and adhesion of the particles to the rotor blades in the gas turbine air compressing device may be impeded.
  • the filters are provided to maintain the functionality of an electricity generation output from the gas turbine.
  • the gas turbine may be switched off such that a filter replacement may be made when the gas turbine is not operating, thereby avoiding some problems related to the deteriorating effects of a gas turbine operation without any filter.
  • this approach leads to other problems, as ruptures in gas turbine operation usually are cumbersome and problematic.
  • a supply stop of electricity arises which may be costly.
  • a pocket filter assembly for removing particles from an air or gas flow, comprising a filter unit comprising a plurality of filter pockets arranged in parallel, wherein the filter pockets have flexible sides facing each other, a pre- filter unit comprising a plurality of filter pockets, wherein each of at least a majority of the filter pockets of the pre-filter unit are arranged within a respective one of the filter pockets of the filter unit, and wherein the pre-filter unit is releasably connected to the filter unit for enabling removal therefrom, and a support structure for supporting the plurality of filter pockets of the filter unit, such that the filter pockets of the pre-filter unit extend within the filter pockets of the filter unit at least a major part of the length thereof, and the support structure comprises support elements arranged to abut the flexible filter pocket sides of the filter pockets of the filter unit such that sideway flexing of the filter pockets of the filter unit is hindered, and a passage of the filter pockets of the pre-filter unit into and out of
  • the support structure facilitates a pre-filter removal and insertion from the filter unit such that the filter unit may be kept in the pocket filter assembly during machine operation, while the pre-filter unit is removed from the filter unit.
  • the support structure simplifies a removal of the pre-filter unit from the filter unit due to filter replacement, repair, or the like, while the filter unit may be kept in the pocket filter assembly such that particles are hindered to enter the turbine.
  • the pocket filter assembly may still provide a functional filter performance at machine operation although the pre-filter unit is removed from the assembly. Consequently, several problems may be avoided related to filter maintenance such as e.g. switching off the machine for which the filter is provided or running the risk of damaging the machine due to particle intrusion if no filter is present.
  • obstacles such as e.g. deteriorated machine operations, supplementary repair costs or machine operation ruptures may be circumvented.
  • the support structure supports the plurality of filter pockets of the filter unit such that the filter pockets of the pre-filter unit extend within the filter pockets of the filter unit at least a major part of the length thereof.
  • each of at least a majority of the filter pockets of the pre-filter unit may be arranged deep within a respective one of the filter pockets of the filter unit.
  • the direction of the air or gas flow should be construed as the direction substantially parallel to the depths of the filter pockets, through the pocket filter assembly.
  • the filter unit comprising a plurality of filter pockets arranged in parallel, it is here meant that the filter pockets having flexible sides facing each other are arranged substantially perpendicular to the direction of the air or gas flow.
  • the support structure comprises support elements arranged to abut the flexible filter pocket sides of the filter pockets of the filter unit such that sideway flexing of the filter pockets of the filter unit is hindered.
  • the support elements counteract e.g. filter pocket bending, folding, interference, or the like, which could, in the absence of the support structure, be subjected to the filter pockets.
  • the support elements hindering the mentioned actions of the filter pockets provide several advantages in this aspects, as filter pocket bending, folding, interference, or the like, may deteriorate the filter properties, reducing the efficiency of removing particles from an air or gas flow.
  • the filter pockets of the first plurality of filter pockets may be formed by a material or materials suited for the removal of particles from an air or gas flow without the need of the material being strengthened by additional materials or structures such as plastics, metals, or the like.
  • filter pockets may be formed by a material adapted for filter performance of particle removal, not
  • complementary material integrated in or applied to the filter pockets to support the structure of the filter pockets of the filter unit may be superfluous.
  • the complementary material may hinder the air or gas flow due to a decreased flow-permeability, thereby deteriorating the filter performance, may be avoided.
  • Another advantage of a homogeneous filter material is that it is cheaper to manufacture and more easily recyclable compared to a filter material comprising integrated material for the support of the filter unit.
  • the possible absence of any complementary material integrated in or applied to support the form of the filter unit may provide a lighter filter which is easier to insert to and remove from the pocket filter assembly, respectively.
  • Materials suited for the removal of particles from an air or gas flow whilst still being air or gas-permeable may be any of, or the combination of, e.g. glass fiber, polypropylene, polyester, spunbonded fabric or the like.
  • the material may be any other material for the removal of particles from an air or gas flow whilst still being air or gas-permeable.
  • these may be textile filter materials such as rayon, nylon, polyacrylonithle, or the like.
  • the pocket filter assembly forms a free passage for the filter pockets of the pre-filter unit into and out of the filter pockets of the filter unit.
  • the pre-filter unit removal from, or insertion into, the filter unit, respectively is relatively unhindered.
  • such an operation becomes relatively straightforward and easy to conduct as the pocket filter assembly provides a relatively un-obstructed path for the pockets of the pre-filter unit.
  • the arrangement of each of at least a majority of the filter pockets of the pre-filter unit within a respective one of the filter pockets of the filter unit becomes facilitated.
  • the free passage enabled by the pocket filter assembly provides a simplified removal of the filter pockets of the pre-filter unit from within the filter pockets of the filter unit.
  • the arrangement as disclosed here provides an easily handed operation.
  • the filter unit may be kept in the pocket filter assembly during pre- filter unit removal from, or insertion into, the filter unit, respectively. This also holds for the support structure, as it does not need to be removed at pre-filter removal or insertion.
  • the support structure is located and arranged such that it does dot obstruct insertion or removal of the pre-filter unit.
  • the filter pocket assembly still provides a filter functionality at operation when the pre-filter unit is removed.
  • the turbine may still be operating although a pre-filter removal and/or insertion is conducted.
  • negative effects related to ruptures in gas turbine operation such as e.g. particle intrusion into the gas turbine or costly electricity supply stops may be circumvented.
  • the filter pockets of the pre-filter unit extend within the filter pockets of the filter unit
  • the filter pockets of the pre-filter unit may extend within the filter pockets of the filter unit to any length between a major part of the length thereof and to the bottom thereof.
  • the filter pockets of the pre- filter unit may extend within the filter pockets of the filter unit to 3/5, 3/4, 4/5 or the like.
  • the filter pockets of the pre-filter unit not necessarily have to extend unitarily within the filter pockets of the filter unit.
  • the more centrally positioned filter pockets in the pre-filter unit may extend within the filter pockets of the filter unit to a first length, whereas the more peripherally positioned filter pockets may extend to a second length, different from the first length.
  • This may, e.g., be embodied such that the more centrally positioned filter pockets in the pre-filter unit may extend within the filter pockets of the filter unit to 4/5 thereof, whereas the more peripherally positioned filter pockets may extend to 3/5 thereof, or vice versa.
  • the outer dimensions of the filter pockets of the pre-filter unit and the inner dimensions of the filter pockets of the filter unit may be substantially equal.
  • each of at least a majority of the filter pockets of the pre-filter unit tightly fit within a respective one of the filter pockets of the filter unit.
  • the filter pockets of the pre-filter unit may be arranged in a close proximity to the filter pockets of the filter unit, an advantage of this arrangement is that the filter performance may be increased. This is realized as an enlarged filter media surface area for the particle collection may be provided, enhancing the performance of the pocket filter assembly.
  • the substantially equal dimensions facilitate an operation wherein the filter pockets of the pre-filter unit are inserted within the filter pockets of the filter unit.
  • filter pockets of the pre-filter unit being e.g. bigger than the filter pockets of the filter unit, may be more difficult to insert.
  • a removal of the pre-filter unit from the filter unit when the pre-filter unit e.g. needs to be replaced by a new filter, or to be cleaned and/or repaired before being reinserted into the filter unit is simplified.
  • the filter pockets of the pre-filter unit may have larger or smaller outer dimensions compared to the inner dimensions of the filter pockets of the filter unit.
  • Filter pockets of the pre-filter unit being smaller that the filter pockets of the filter unit further facilitates an insertion or removal of the filter pockets of the pre-filter unit within the filter pockets of the filter unit.
  • the ratio between the circumference of the filter pockets of the pre-filter unit and the circumference of the filter pockets of the filter unit may be 2/3, 1/2, or less.
  • Filter pockets of the pre-filter unit being larger that the filter pockets of the filter unit may be an embodiment of the present invention. However, deteriorating effects related to filter pockets of the pre-filter unit being larger that the filter pockets of the filter unit may be present.
  • the dimensions of the filter pockets of the pre-filter unit in relation to the dimensions of the filter pockets of the filter unit not necessarily have to be unitary.
  • there may be a first ratio between the circumferences of the more centrally positioned filter pockets in the pre-filter unit and the respective filter pockets of the filter unit whereas there may be a second ratio between the circumferences of the more peripherally positioned filter pockets in the pre-filter unit and the respective filter pockets of the filter unit, the first and second ratio being different.
  • the ratio between the circumferences of the more centrally positioned filter pockets in the pre-filter unit and the respective filter pockets of the filter unit may be 2/3, whereas the ratio between the
  • circumferences of the more peripherally positioned filter pockets in the pre- filter unit and the respective filter pockets of the filter unit may be 1/2, or vice versa.
  • the support elements of the pocket filter assembly are arranged to abut the flexible filter pocket sides of a respective one filter pocket of the filter unit such that the filter pockets arranged in parallel are kept apart.
  • This separation of a respective one filter pockets of the filter unit provides an improved filter operation, regarding numerous aspects.
  • the support elements provide a better operation as filter pockets coming into contact with each other deteriorate the air or gas flow through the pocket filter assembly. By keeping the filter pockets apart, additional filter pocket wear as a result of filter pockets flapping against each other during operation, may be avoided.
  • filter pockets kept apart contribute to an increased stability of the pocket filter assembly at operation. When the filter pockets are kept apart, an improved pocket filter assembly maintenance is provided, as maintenance activities such as e.g. cleaning between the filter pockets and detection of filter pocket defects are facilitated. Additionally, the arrangement contributes to the simplified operation of removal and/or insertion of the pre-filter unit from and/or into, respectively, the filter unit.
  • the support elements of the pocket filter assembly may be arranged to abut one side of a respective one flexible filter pocket of the filter unit. This may be advantageous in cases when e.g. the arrangement of support elements are superfluous on one side of a respective one flexible filter pocket.
  • the support elements may abut the outsides of the flexible filter pocket sides of a respective one filter pocket of the filter unit. This further improves the pocket filter assembly regarding several aspects.
  • the insertion, or removal, of the filter pockets of the pre-filter unit within the filter pockets of the filter unit may be performed in a
  • the support elements being non-obstructive in this respect.
  • the elements interfere to a lesser extent with the insertion or removal of the filter pockets of the pre-filter unit.
  • the arrangement of the support elements abutting the outside of the flexible filter pocket sides of the filter unit decreases the risk of damaging the filter pockets of the pre-filter unit at insertion.
  • the insertion of the filter pockets of the pre-filter may extend even deeper within the filter pockets of the filter unit.
  • any maintenance, repair and/or cleaning of the support elements such as e.g. welding, replacements or the like, becomes easier with the support elements provided on the downstream side of the respective one filter pocket of the filter unit.
  • downstream direction should, in this context, be construed as the direction of flow from the outside ambience through the pocket filter assembly.
  • downstream side it is meant the leeward side.
  • upstream should be construed as the direction of flow reverse to the "downstream” direction.
  • upstream side it is meant the windward side.
  • the support elements may comprise bars, grids, meshes, or the like.
  • the support elements provide a relatively light-weight pocket filter assembly, such to enable that e.g. filter unit replacements and/or maintenance of the support elements may be
  • the material of the support elements may be any material, or any combination of materials, providing a substantially rigid structure of the elements such as metal, plastics, or the like. With this, the material of the support elements provides a rigid structure such that sideway flexing of the filter pockets of the filter unit is hindered. As a consequence, e.g. filter pocket bending, folding, interference, or the like, deteriorating the filter performance, may be circumvented.
  • the support elements constructed of e.g. bars, grids, meshes, or the like may be provided to support the filter pockets of the filter unit in many ways.
  • bars may extend with the depth of the filter pockets, substantially in the direction of the air or gas flow.
  • bars may extend perpendicular to the depth of the filter pockets.
  • support elements provided as elliptical rings, encircling the filter pockets of the filter unit may be possible embodiments of the present invention.
  • the support elements may partially enclose a respective one filter pocket of the filter unit, the support elements being v-shaped, cone-shaped, pyramid-shaped or the like.
  • the shapes of the support elements may be provided in the approximate shapes and sizes of a respective one filter pockets of the filter unit, such as to adapt the support elements to the filter pockets in the pocket filter assembly.
  • v-shaped should, in this context, be construed as a structure wherein the distance between support elements decreases constantly from the mouth to the tip of a respective one filter pocket of the filter unit, which pocket the elements partially enclose.
  • support elements provided around the mouth of a filter pocket extend to abut the outsides of the flexible filter pocket sides of a respective one filter pocket of the filter unit, such that the elements come together in a point so as to form a v-shape.
  • the terms "cone-shaped” and “pyramid-shaped” should be construed similarly, i.e. that the support elements provided around the mouth of a filter pocket extend from the mouths to the tips of the flexible filter pocket sides of a respective one filter pocket of the filter unit, such that the elements form a v-shape or a pyramid-shape.
  • v-shaped cone-shaped
  • pyramid- shaped it is meant the profile of the structure that the support elements provide.
  • the support elements may be provided as spirals around a respective one filter pocket of the filter unit, wherein the spiral profiles may be cone-shaped, v-shaped, pyramid-shaped, or the like, such that the diameter of the spirals decrease from the mouths to the tips of a respective one filter pocket of the filter unit.
  • the support elements are constructed such that only a part of a respective one filter pocket of the filter unit is enclosed, to ensure a substantially unobstructed permeability of air or gas flow through the pocket filter assembly.
  • the shapes of the support elements may provide a cage-like enclosure of a respective one filter pocket of the filter unit.
  • the support elements may partially enclose a respective one filter pocket of the filter unit, wherein the elements however only extend to a part of the depths of the filter pockets.
  • support elements may be provided to extend from the mouth of a respective one filter pocket of the filter unit to approximately half the depth of a respective one filter pocket of the filter unit.
  • the v-shaped elements may instead of enclosing the filter pockets of the filter unit be provided in the space between two adjacent filter pockets of the filter unit.
  • a support element provided at the mouth of a first filter pocket of the filter unit may extend to come together in a point with a support element provided at the mouth of a second filter pocket of the filter unit so as to form a v-shape in the space between the two adjacent filter pockets.
  • the support elements of the pocket filter assembly may abut both sides of a respective one filter pocket of the filter unit substantially parallel to the depth of the filter pockets of the filter unit. This further hinders sideway flexing of the filter pockets of the filter unit such that e.g. filter pocket bending, folding, interference, or the like, deteriorating the filter performance, may be circumvented.
  • the support elements abutting both sides of the respective filter pocket of the filter unit may be structurally different, i.e. one embodiment may be that for one side of each filter, the support elements may be bars, whereas for the other side, the support elements may be meshes.
  • the support elements of the pocket filter assembly may symmetrically abut the sides of the respective one filter pocket of the filter unit. This may especially be the case when pocket filters are cone-shaped, pyramid-shaped, or the like. As another example, the support elements of the pocket filter assembly may instead asymmetrically abut the sides of the respective filter pocket of the filter unit. This embodiment could be advantageous in cases when supplementary support is needed for the filter pockets of the filter unit. As an example, if the mounting of the pocket filter assembly is provided such that there is an angle between the depths of the filter pockets of the filter unit and the direction of the gas or air flow, a supplementary support may be needed on the downstream sides of the filter pockets.
  • the support elements may constitute a framework structure comprising a plurality of pairs of v-shaped bars abutting the sides of the respective one filter pocket of the filter unit, the framework structure further comprising supplementary bars to substantially fix the positions of the v-shaped bars of the framework structure. This arrangement contributes to the stability of the pocket filter assembly at gas turbine operation.
  • frame structure it is meant a
  • the framework structure provided in the filter pocket assembly should still ensure a permeability of air or gas flow through the pocket filter assembly such to provide a satisfactory filter functionality.
  • the plurality of v-shaped bars may instead be cone-shaped, pyramid-shaped, or the like.
  • the supplementary bars may instead be supplementary grids, meshes, or the like, such to substantially fix the positions of the bars of the framework structure.
  • the filter unit is provided on a first frame structure
  • the pre-filter unit is provided on a second frame structure
  • the framework structure constitutes a constituent unit
  • the filter unit is inserted into the framework structure
  • the pre-filter unit is inserted into the filter unit
  • the respective units are releasably connected to one another.
  • the pre-filter unit and the filter unit such as to simplify an insertion of the pockets of the pre-filter unit within the filter pockets of the filter unit.
  • the frame structures also provide an improved stability of the pocket filter assembly at operation, as the frame structures enable an improved relative positioning of the filter pockets of the pre-filter unit and the filter unit.
  • the attachment of the second frame structure to the first frame structure may be provided by locking elements, wherein e.g. apertures or recesses may be provided on the first frame structure, while e.g. projections are provided on the second frame structure, or vice versa.
  • the material of the frame structures may be any material providing a rigid structure of the frames such as metal, plastics, or the like.
  • the frame structures may be formed by galvanized steel plates.
  • Figure 1 shows a profile view of a filter unit according to an
  • Figure 2 shows a perspective view of a filter unit according to an exemplifying embodiment of the invention.
  • Figure 3 shows a side view of a filter unit according to an exemplifying embodiment of the invention.
  • Figure 4 shows a perspective view of a filter unit according to an exemplifying embodiment of the invention.
  • Figure 5 shows a perspective view of a pre-filter unit according to an exemplifying embodiment of the invention.
  • Figure 6 shows a perspective view of a pocket filter assembly according to an exemplifying embodiment of the invention.
  • Figure 1 shows a profile view of a pocket filter assembly 1 comprising a filter unit 2 having six filter pockets 3.
  • the filter pockets 3 are arranged in parallel, wherein the filter pockets 3 have flexible sides 4 facing each other.
  • the profile view of the figure is in a direction perpendicular to an axis parallel to the elongated filter pockets 3 and perpendicular to the direction of the air or gas flow 5.
  • the filter pockets 3 are elongated substantially in the downstream direction of the air or gas flow 5.
  • the fabrication of the filter pockets 3 result in welds 6, elongated on the sides of the filter pockets 3.
  • the downstream direction of the air or gas flow 5 is defined from right to left, i.e. the flow 5 enters the filter pockets 3 of the filter unit 2 through mouths 7 provided on the right hand portion of the filter pockets 3, and the flow 5 flows through the filter pockets 3 and exits the filter unit 2 to the left.
  • the profiles of the filter pockets 3 are v-shaped such that the circumferences of the filter pockets 3 decrease with the depths of the filter pockets 3, in the downstream direction of the air or gas flow 5.
  • the circumferences of the filter pockets 3 decrease from the mouths 7 to the tips 8 of the filter pockets 3, the tips 8 provided on the left hand portion of the filter pockets 3.
  • a support structure 9 for supporting the respective one filter pocket 3 of the filter unit 2 is provided in the pocket filter assembly 1 , wherein the support structure 9 comprises support elements 10.
  • the support structure 9 comprises support elements 10.
  • a plurality of support element pairs 11 are provided in v-shapes.
  • the two support elements 10 of each support element pair 11 are separated at the mouth 7 of the respective one filter pocket 3 and extend from the mouths 7 of the respective one filter pocket 3, the support elements 10 abutting both outer, downstream sides of the flexible filter pocket sides 4 of the filter pockets 3 of the filter unit 2.
  • the support element pairs 11 partially enclose a respective one filter pocket 3 of the filter unit 2, and the planes formed by each support element pair 11 are perpendicular to the elongated direction of the filter pockets 3.
  • the support elements pairs 11 provide a cage-like enclosure of the filter pockets of the filter unit.
  • the filter unit 2 and the support structure 9 for supporting the plurality of filter pockets 3 of the filter unit 2 are releasably connected to a first frame structure 12.
  • the first frame structure 12 is arranged in a plane at the mouths 7 of the filter pockets 3 of the filter unit 2, the plane being perpendicular to the direction of the air or gas flow 5.
  • the filter pockets 3 and the plurality of support element pairs 11 are attached to the first frame structure 12, the filter pockets 3 being equidistantly separated.
  • FIG. 1 A perspective view of the pocket filter assembly 1 shown in figure 1 is shown in figure 2.
  • Each of the six filter pockets 3 of the filter unit 2 is supported by the support structure 9 comprising five pairs 11 of support elements 10.
  • the support element pairs 11 abutting both outer, downstream sides of the flexible filter pocket sides 4, are provided in v-shapes.
  • the openings of the v-shaped support element pairs 11 are provided at the mouths 7 of a respective one filter pocket 3.
  • the closures of the v-shaped support element pairs 11 are provided beyond the tips 8 of the filter pockets 3.
  • the five support element pairs 11 provided for a respective one filter pocket 3 are arranged in parallel, such that the planes formed by each pair of the support element pairs 11 face each other. Furthermore, the element pairs 11 are equidistantly separated. The distance along the width of the filter pocket 3 between the two outermost positioned support element pairs 11 is within the width of the filter pocket 3.
  • a supplementary support element 13 is diagonally elongated on the outermost side 4 of the filter pocket 3.
  • the supplementary support element 13 is provided on the outer, downstream side of the five support elements 10 of the five support element pairs 11 of the outermost filter pocket 3.
  • the supplementary support element 13 extends diagonally from the mouth of the outermost filter pocket 3, at one of the outermost positioned support elements 10, to a position 14 where the two support elements 10 of the other outermost positioned support element pair 11 of the five support element pairs 11 come in contact. At this contact, the tips of the support element pair 11 and the supplementary support element 13 are welded together. Furthermore, welds are provided at the intersections of the supplementary support element 13 with the five support elements 10 on the outermost side 4 of the filter pocket 3 such to ensure a stability of the support elements 10.
  • Figure 3 shows a side view of a filter unit 2 of the pocket filter assembly 1 in a direction perpendicular to an axis parallel to the elongated filter pockets 3 and perpendicular to the downstream direction of the air or gas flow 5.
  • the figure shows the outermost side 4 of a filter pocket 3 of the filter unit 2.
  • the side 4 is substantially rectangular, wherein the long side is substantially elongated in the direction of the air or gas flow 5.
  • the five pairs 11 of support elements 10 of each of the filter pockets 3 (of which pairs 11 only the five outermost support elements 10 are shown) abut both outer, downstream sides of the flexible filter pocket sides 4.
  • the five support element pairs 11 provided for each filter pocket 3 are arranged in parallel, such that the planes formed by each pair of the support element pairs 11 face each other.
  • the supplementary support element 13 is diagonally elongated on the outermost side 4 of the filter pocket 3.
  • Figure 4 shows a view of the filter unit 2 of the pocket filter assembly 1 in the downstream direction of the air or gas flow 5.
  • the rectangular-shaped first frame structure 12 comprises four peripheral frame portions 12a, 12b, 12c, 12d and five separating bars 15 extending separately, and in parallel to each other between the two opposite peripheral frame portions 12b, 12d, so as to define six longitudinal mouths 7 of the filter pockets 3.
  • the six filter pockets 3 of the filter unit 2 are provided side by side in the first frame structure 12 and are attached to the first frame structure 12.
  • the filter pockets are further attached to the five separating bars 15.
  • Figure 5 shows a perspective view of a pre-filter unit 16 of the pocket filter assembly 1 , the pre-filter unit 16 having six filter pockets 17.
  • the filter pockets 16 are elongated substantially in the downstream direction of the air or gas flow entering the filter pockets 17 through mouths provided on the right hand portion of the filter pockets 17.
  • the profiles of the filter pockets 17 are v-shaped such that the circumferences of the filter pockets 17 decrease in the downstream direction of the air or gas flow 5.
  • a rectangular shaped, second frame structure 18 is arranged at the mouths 7 of the filter pockets 17 of the pre-filter unit 16.
  • the filter pockets 17 are releasably connected to the second frame structure 18.
  • Figure 6 shows a perspective view of a pocket filter assembly 1 comprising a filter unit 2 and a pre-filter unit 16, both as described previously. At least a majority of the filter pockets 17 of the pre-filter unit 16 may be arranged within a respective one of the filter pockets 3 of the filter unit 2.
  • the pre-filter unit 16 is releasably connected to the filter unit 2 for enabling removal therefrom.
  • the outer dimensions of the filter pockets 17 of the pre- filter unit 16 and the inner dimensions of the filter pockets 3 of the filter unit 2 are substantially equal, such that the filter pockets 17 of the pre-filter unit 16 tightly fit within a respective one of the filter pockets 3 of the filter unit 2.
  • the filter pockets 17 of the pre-filter unit 16 are formed to extend within the filter pockets 3 of the filter unit 2 substantially to the bottom thereof.
  • the second frame structure 18 is releasably connected to the first frame structure 12 such that the filter pockets 17 of the pre-filter unit 16 provided on the first frame structure 12 extend within the filter pockets 3 of the filter unit 2 provided on the second frame structure
  • the attachment of the second frame structure 18 to the first frame structure 12 may be provided by locking elements, wherein e.g. apertures or recesses may be provided on the first frame structure 12, while e.g.
  • projections are provided on the second frame structure 18, or vice versa.
  • any object as described may take on any other geometrical shape.
  • the rectangular-shaped first frame structure 12 and second frame structure 18 may instead be triangular, circular, quadratic or pentagonal-shaped.
  • the filter pockets 3, 17 of the filter unit 2 and the pre-filter unit 16, respectively may be cone-shaped, pyramid-shaped or the like.
  • any embodiment related to the number of e.g. frame structures 12, 18, filter pockets 3, 17, support elements 10, supplementary support elements 13, or the like may be varied.
  • any embodiment related to the placement of the above, or other, elements of the pocket filter assembly 1 e.g. frame structures 12, 18, filter pockets 3, 17, support elements 10, supplementary support elements 13, or the like may be varied.
  • supplementary support elements 13 provided on the opposite side of the first frame structure, connecting a plurality of tips 14 of the support element pairs 11 such to increase the stability of the support elements 10.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
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  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Filtering Of Dispersed Particles In Gases (AREA)

Abstract

A pocket filter assembly for removing particles from an air or gas flow, comprising a filter unit comprising a plurality of filter pockets, a pre-filter unit comprising a plurality of filter pockets, wherein each of at least a majority of the filter pockets of the pre-filter unit are arranged within a respective one of the filter pockets of the filter unit, and wherein the pre-filter unit is releasably connected to the filter unit, and a support structure such that the filter pockets of the pre-filter unit extend within the filter pockets of the filter unit at least a major part of the length thereof, and the support structure comprises support elements such that sideway flexing of the filter pockets of the filter unit is hindered, and a free passage for the filter pockets of the pre-filter unit into and out of the filter pockets of the filter unit is formed.

Description

CAMFLO GT WIREFRAME
FIELD OF THE INVENTION
The present invention relates to a pocket filter assembly for removing particles from an air or gas flow wherein the pocket filter assembly may, for example, be provided in an air intake device for a gas turbine, such to prevent particles to enter the gas turbine.
BACKGROUND OF THE INVENTION
Filters are often used to remove solid particles such as e.g. dust, pollen, mold, or sand from an air flow. Especially in applications where air quality is important, notably in building ventilation systems and in engines, filters are often indispensible for the provision of clean air.
As an example, gas turbines are generally operated with one or more filters for removing particles from an air or gas flow such that particles are hindered to enter the turbine. With this, potential damage risks such as e.g. turbine fouling, corrosion, and adhesion of the particles to the rotor blades in the gas turbine air compressing device may be impeded. Thus, the filters are provided to maintain the functionality of an electricity generation output from the gas turbine.
After a certain time of operation, dependent on the ambient conditions in which the gas turbine operates, a large quantity of accumulated particles in the filters deteriorate the function of the intake device. In other words, the air or gas flow resistance increases which may, as a consequence, result in an electricity output loss of the gas turbine. Moreover, other ambient conditions such as sand storms, snow storms, rain, heat, cold, or the like may negatively affect the performance of the filters. In the above mentioned, or other, situations, the filters may have to be replaced to regain the sought air filter efficiency. However, a filter
replacement may raise several problems. If the filter is removed from an intake device during gas turbine operation, the prevention of particles entering the gas turbine at the air intake is impaired. Such a particle intrusion into the gas turbine may lead to a deteriorated gas turbine operation, costly
maintenance, and/or possibly, a gas turbine breakdown. On the other hand, the gas turbine may be switched off such that a filter replacement may be made when the gas turbine is not operating, thereby avoiding some problems related to the deteriorating effects of a gas turbine operation without any filter. However, this approach leads to other problems, as ruptures in gas turbine operation usually are cumbersome and problematic. Furthermore, by switching off the gas turbine, a supply stop of electricity arises which may be costly.
SUMMARY OF THE INVENTION
It is an object of the present invention to mitigate at least one of the above problems and to provide an improved filter assembly.
This and other objects are achieved by providing a pocket filter assembly having the features defined in the independent claim. Preferred embodiments are defined in the dependent claims.
According to a first embodiment of the present invention, this is realized by a pocket filter assembly for removing particles from an air or gas flow, comprising a filter unit comprising a plurality of filter pockets arranged in parallel, wherein the filter pockets have flexible sides facing each other, a pre- filter unit comprising a plurality of filter pockets, wherein each of at least a majority of the filter pockets of the pre-filter unit are arranged within a respective one of the filter pockets of the filter unit, and wherein the pre-filter unit is releasably connected to the filter unit for enabling removal therefrom, and a support structure for supporting the plurality of filter pockets of the filter unit, such that the filter pockets of the pre-filter unit extend within the filter pockets of the filter unit at least a major part of the length thereof, and the support structure comprises support elements arranged to abut the flexible filter pocket sides of the filter pockets of the filter unit such that sideway flexing of the filter pockets of the filter unit is hindered, and a passage of the filter pockets of the pre-filter unit into and out of the filter pockets of the filter unit is enabled.
Due to the pocket filter assembly as disclosed here, the support structure facilitates a pre-filter removal and insertion from the filter unit such that the filter unit may be kept in the pocket filter assembly during machine operation, while the pre-filter unit is removed from the filter unit. Thus, the support structure simplifies a removal of the pre-filter unit from the filter unit due to filter replacement, repair, or the like, while the filter unit may be kept in the pocket filter assembly such that particles are hindered to enter the turbine. With this, the pocket filter assembly may still provide a functional filter performance at machine operation although the pre-filter unit is removed from the assembly. Consequently, several problems may be avoided related to filter maintenance such as e.g. switching off the machine for which the filter is provided or running the risk of damaging the machine due to particle intrusion if no filter is present. Thus, with the pocket filter assembly as disclosed here, obstacles such as e.g. deteriorated machine operations, supplementary repair costs or machine operation ruptures may be circumvented.
The support structure supports the plurality of filter pockets of the filter unit such that the filter pockets of the pre-filter unit extend within the filter pockets of the filter unit at least a major part of the length thereof. In other words, each of at least a majority of the filter pockets of the pre-filter unit may be arranged deep within a respective one of the filter pockets of the filter unit. With this assembly, the filter performance is ameliorated, as the depth of the filter pockets of the pre-filter unit into the filter pockets of the filter unit provides a large pre-filter pocket area for air or gas flow filtering. This is realized as filter pockets with more shallow depths usually provide an inferior filter functionality. Thus the filter efficiency of removing particles from an air or gas flow with the pocket filter assembly as described here, is enhanced.
The direction of the air or gas flow should be construed as the direction substantially parallel to the depths of the filter pockets, through the pocket filter assembly. With the filter unit comprising a plurality of filter pockets arranged in parallel, it is here meant that the filter pockets having flexible sides facing each other are arranged substantially perpendicular to the direction of the air or gas flow.
Moreover, the support structure comprises support elements arranged to abut the flexible filter pocket sides of the filter pockets of the filter unit such that sideway flexing of the filter pockets of the filter unit is hindered. Thus, the support elements counteract e.g. filter pocket bending, folding, interference, or the like, which could, in the absence of the support structure, be subjected to the filter pockets. The support elements hindering the mentioned actions of the filter pockets provide several advantages in this aspects, as filter pocket bending, folding, interference, or the like, may deteriorate the filter properties, reducing the efficiency of removing particles from an air or gas flow.
By the mitigation of the sideway flexing of the filter pockets, another advantage provided by the support elements is a contribution to the service life of the filter pockets. This is realized as a sideway flexing may increase the filter pocket wear as a result of e.g. bending fatigue or interference with other filter pockets at operation.
Another advantage of the support elements arranged to abut the flexible filter pocket sides of the filter pockets of the filter unit, the filter pockets of the first plurality of filter pockets may be formed by a material or materials suited for the removal of particles from an air or gas flow without the need of the material being strengthened by additional materials or structures such as plastics, metals, or the like. Explained differently, filter pockets may be formed by a material adapted for filter performance of particle removal, not
necessarily adapted to support its own structure. This is advantageous regarding several aspects. Considering the filter performance, any
complementary material integrated in or applied to the filter pockets to support the structure of the filter pockets of the filter unit may be superfluous. Thus, such filter units, wherein the complementary material may hinder the air or gas flow due to a decreased flow-permeability, thereby deteriorating the filter performance, may be avoided. Another advantage of a homogeneous filter material is that it is cheaper to manufacture and more easily recyclable compared to a filter material comprising integrated material for the support of the filter unit.
Regarding the aspect of filter replacement, the possible absence of any complementary material integrated in or applied to support the form of the filter unit may provide a lighter filter which is easier to insert to and remove from the pocket filter assembly, respectively.
Manufacturing measures such as corrugation, strengthening and/or stiffening of the filters to support filter structures, may be laborious and/or costly. As a consequence, a high cost related to the filter manufacturing may be especially unwanted in the cases of e.g. gas turbines operating in extreme conditions, wherein filters often need to be replaced more frequently compared to more normal conditions.
Materials suited for the removal of particles from an air or gas flow whilst still being air or gas-permeable may be any of, or the combination of, e.g. glass fiber, polypropylene, polyester, spunbonded fabric or the like.
However, in other embodiments, the material may be any other material for the removal of particles from an air or gas flow whilst still being air or gas-permeable. Examples of these may be textile filter materials such as rayon, nylon, polyacrylonithle, or the like.
Additionally, the pocket filter assembly forms a free passage for the filter pockets of the pre-filter unit into and out of the filter pockets of the filter unit. With this, it is meant that the pre-filter unit removal from, or insertion into, the filter unit, respectively, is relatively unhindered. In other words, such an operation becomes relatively straightforward and easy to conduct as the pocket filter assembly provides a relatively un-obstructed path for the pockets of the pre-filter unit. Thus, the arrangement of each of at least a majority of the filter pockets of the pre-filter unit within a respective one of the filter pockets of the filter unit becomes facilitated.
Analogously, the free passage enabled by the pocket filter assembly provides a simplified removal of the filter pockets of the pre-filter unit from within the filter pockets of the filter unit. Thus, when a pre-filter unit needs to be removed from the pocket filter assembly to e.g. be replaced by a new pre- filter unit, or to be cleaned and/or repaired before being reinserted into the filter unit, the arrangement as disclosed here provides an easily handed operation. The filter unit may be kept in the pocket filter assembly during pre- filter unit removal from, or insertion into, the filter unit, respectively. This also holds for the support structure, as it does not need to be removed at pre-filter removal or insertion. Thus, the support structure is located and arranged such that it does dot obstruct insertion or removal of the pre-filter unit.
Due to the remaining filter unit, the filter pocket assembly still provides a filter functionality at operation when the pre-filter unit is removed. For the application of e.g. a gas turbine, the turbine may still be operating although a pre-filter removal and/or insertion is conducted. Thereby, negative effects related to ruptures in gas turbine operation such as e.g. particle intrusion into the gas turbine or costly electricity supply stops may be circumvented.
According to an embodiment of the present invention, the filter pockets of the pre-filter unit extend within the filter pockets of the filter unit
substantially to the bottom thereof. This arrangement further enhances the filter performance at operation, as the depth of the filter pockets of the pre- filter unit into the bottom of the filter pockets of the filter unit may provide an even larger pre-filter pocket area. Thus, with this pocket filter assembly, the particle removing efficiency from an air or gas flow is enhanced even further.
The filter pockets of the pre-filter unit may extend within the filter pockets of the filter unit to any length between a major part of the length thereof and to the bottom thereof. As an example, the filter pockets of the pre- filter unit may extend within the filter pockets of the filter unit to 3/5, 3/4, 4/5 or the like. With this, it should also be understood that the filter pockets of the pre-filter unit not necessarily have to extend unitarily within the filter pockets of the filter unit. As an example, the more centrally positioned filter pockets in the pre-filter unit may extend within the filter pockets of the filter unit to a first length, whereas the more peripherally positioned filter pockets may extend to a second length, different from the first length. This may, e.g., be embodied such that the more centrally positioned filter pockets in the pre-filter unit may extend within the filter pockets of the filter unit to 4/5 thereof, whereas the more peripherally positioned filter pockets may extend to 3/5 thereof, or vice versa.
According to an embodiment of the present invention, the outer dimensions of the filter pockets of the pre-filter unit and the inner dimensions of the filter pockets of the filter unit may be substantially equal. With this, it is meant that each of at least a majority of the filter pockets of the pre-filter unit tightly fit within a respective one of the filter pockets of the filter unit. As the filter pockets of the pre-filter unit may be arranged in a close proximity to the filter pockets of the filter unit, an advantage of this arrangement is that the filter performance may be increased. This is realized as an enlarged filter media surface area for the particle collection may be provided, enhancing the performance of the pocket filter assembly.
Furthermore, the substantially equal dimensions facilitate an operation wherein the filter pockets of the pre-filter unit are inserted within the filter pockets of the filter unit. As a comparison, filter pockets of the pre-filter unit being e.g. bigger than the filter pockets of the filter unit, may be more difficult to insert. Analogously, a removal of the pre-filter unit from the filter unit when the pre-filter unit e.g. needs to be replaced by a new filter, or to be cleaned and/or repaired before being reinserted into the filter unit, is simplified.
However, in other embodiments of the present invention, the filter pockets of the pre-filter unit may have larger or smaller outer dimensions compared to the inner dimensions of the filter pockets of the filter unit.
Filter pockets of the pre-filter unit being smaller that the filter pockets of the filter unit further facilitates an insertion or removal of the filter pockets of the pre-filter unit within the filter pockets of the filter unit. As an example, the ratio between the circumference of the filter pockets of the pre-filter unit and the circumference of the filter pockets of the filter unit may be 2/3, 1/2, or less.
Filter pockets of the pre-filter unit being larger that the filter pockets of the filter unit may be an embodiment of the present invention. However, deteriorating effects related to filter pockets of the pre-filter unit being larger that the filter pockets of the filter unit may be present.
With this, it should also be understood that the dimensions of the filter pockets of the pre-filter unit in relation to the dimensions of the filter pockets of the filter unit not necessarily have to be unitary. As an example, there may be a first ratio between the circumferences of the more centrally positioned filter pockets in the pre-filter unit and the respective filter pockets of the filter unit, whereas there may be a second ratio between the circumferences of the more peripherally positioned filter pockets in the pre-filter unit and the respective filter pockets of the filter unit, the first and second ratio being different. More specifically, the ratio between the circumferences of the more centrally positioned filter pockets in the pre-filter unit and the respective filter pockets of the filter unit may be 2/3, whereas the ratio between the
circumferences of the more peripherally positioned filter pockets in the pre- filter unit and the respective filter pockets of the filter unit may be 1/2, or vice versa.
In an embodiment of the invention, the support elements of the pocket filter assembly are arranged to abut the flexible filter pocket sides of a respective one filter pocket of the filter unit such that the filter pockets arranged in parallel are kept apart. This separation of a respective one filter pockets of the filter unit provides an improved filter operation, regarding numerous aspects. Firstly, the support elements provide a better operation as filter pockets coming into contact with each other deteriorate the air or gas flow through the pocket filter assembly. By keeping the filter pockets apart, additional filter pocket wear as a result of filter pockets flapping against each other during operation, may be avoided. Furthermore, filter pockets kept apart contribute to an increased stability of the pocket filter assembly at operation. When the filter pockets are kept apart, an improved pocket filter assembly maintenance is provided, as maintenance activities such as e.g. cleaning between the filter pockets and detection of filter pocket defects are facilitated. Additionally, the arrangement contributes to the simplified operation of removal and/or insertion of the pre-filter unit from and/or into, respectively, the filter unit.
According to an embodiment of the invention, the support elements of the pocket filter assembly may be arranged to abut one side of a respective one flexible filter pocket of the filter unit. This may be advantageous in cases when e.g. the arrangement of support elements are superfluous on one side of a respective one flexible filter pocket.
According to an embodiment, the support elements may abut the outsides of the flexible filter pocket sides of a respective one filter pocket of the filter unit. This further improves the pocket filter assembly regarding several aspects. The insertion, or removal, of the filter pockets of the pre-filter unit within the filter pockets of the filter unit may be performed in a
straightforward manner, the support elements being non-obstructive in this respect. In other words, with the mentioned arrangement of the support elements, the elements interfere to a lesser extent with the insertion or removal of the filter pockets of the pre-filter unit.
Furthermore, the arrangement of the support elements abutting the outside of the flexible filter pocket sides of the filter unit, i.e. the support elements abutting the downstream side, decreases the risk of damaging the filter pockets of the pre-filter unit at insertion. Also, with the absence of any support elements on the inside of the filter unit, i.e. on the upstream side, the insertion of the filter pockets of the pre-filter may extend even deeper within the filter pockets of the filter unit. Moreover, any maintenance, repair and/or cleaning of the support elements such as e.g. welding, replacements or the like, becomes easier with the support elements provided on the downstream side of the respective one filter pocket of the filter unit.
Here, the term "downstream direction", should, in this context, be construed as the direction of flow from the outside ambience through the pocket filter assembly. Analogously, with the term "downstream side", it is meant the leeward side.
The term "upstream" should be construed as the direction of flow reverse to the "downstream" direction. Analogously, with the term "upstream side", it is meant the windward side.
Furthermore, by "sideway flexing", it is here meant a flexing of the parallel filter pockets in a direction substantially perpendicular to the planes of the filter pocket sides and substantially perpendicular to the direction of the air or gas flow. According to an embodiment of the invention, the support elements may comprise bars, grids, meshes, or the like. By this, the filter pockets of the filter unit are supported by the support elements, still ensuring the
permeability of the air or gas flow through the pocket filter assembly. This means that the construction of the support elements does not notably obstruct the air or gas flow through the filter, yet still providing a sufficient support for the filter pockets of the filter unit such that the mentioned advantages are obtained. The suggested embodiments of the support elements provide a relatively light-weight pocket filter assembly, such to enable that e.g. filter unit replacements and/or maintenance of the support elements may be
conveniently performed.
The material of the support elements may be any material, or any combination of materials, providing a substantially rigid structure of the elements such as metal, plastics, or the like. With this, the material of the support elements provides a rigid structure such that sideway flexing of the filter pockets of the filter unit is hindered. As a consequence, e.g. filter pocket bending, folding, interference, or the like, deteriorating the filter performance, may be circumvented.
It should be noted that the support elements constructed of e.g. bars, grids, meshes, or the like may be provided to support the filter pockets of the filter unit in many ways. As an example, bars may extend with the depth of the filter pockets, substantially in the direction of the air or gas flow.
Alternatively, bars may extend perpendicular to the depth of the filter pockets. Moreover, support elements provided as elliptical rings, encircling the filter pockets of the filter unit may be possible embodiments of the present invention.
According to another embodiment of the present invention, the support elements may partially enclose a respective one filter pocket of the filter unit, the support elements being v-shaped, cone-shaped, pyramid-shaped or the like. As an example, the shapes of the support elements may be provided in the approximate shapes and sizes of a respective one filter pockets of the filter unit, such as to adapt the support elements to the filter pockets in the pocket filter assembly. The term "v-shaped" should, in this context, be construed as a structure wherein the distance between support elements decreases constantly from the mouth to the tip of a respective one filter pocket of the filter unit, which pocket the elements partially enclose. In other words, support elements provided around the mouth of a filter pocket extend to abut the outsides of the flexible filter pocket sides of a respective one filter pocket of the filter unit, such that the elements come together in a point so as to form a v-shape.
Analogously, the terms "cone-shaped" and "pyramid-shaped" should be construed similarly, i.e. that the support elements provided around the mouth of a filter pocket extend from the mouths to the tips of the flexible filter pocket sides of a respective one filter pocket of the filter unit, such that the elements form a v-shape or a pyramid-shape.
Furthermore, by the terms "v-shaped", "cone-shaped" and "pyramid- shaped", it is meant the profile of the structure that the support elements provide. As an example, the support elements may be provided as spirals around a respective one filter pocket of the filter unit, wherein the spiral profiles may be cone-shaped, v-shaped, pyramid-shaped, or the like, such that the diameter of the spirals decrease from the mouths to the tips of a respective one filter pocket of the filter unit.
With the term "partially", it is here meant that the support elements are constructed such that only a part of a respective one filter pocket of the filter unit is enclosed, to ensure a substantially unobstructed permeability of air or gas flow through the pocket filter assembly. As an example, the shapes of the support elements may provide a cage-like enclosure of a respective one filter pocket of the filter unit. Alternatively, the support elements may partially enclose a respective one filter pocket of the filter unit, wherein the elements however only extend to a part of the depths of the filter pockets. As an example, support elements may be provided to extend from the mouth of a respective one filter pocket of the filter unit to approximately half the depth of a respective one filter pocket of the filter unit.
As another alternative, the v-shaped elements may instead of enclosing the filter pockets of the filter unit be provided in the space between two adjacent filter pockets of the filter unit. As an example, a support element provided at the mouth of a first filter pocket of the filter unit may extend to come together in a point with a support element provided at the mouth of a second filter pocket of the filter unit so as to form a v-shape in the space between the two adjacent filter pockets.
According to yet another embodiment of the present invention, the support elements of the pocket filter assembly may abut both sides of a respective one filter pocket of the filter unit substantially parallel to the depth of the filter pockets of the filter unit. This further hinders sideway flexing of the filter pockets of the filter unit such that e.g. filter pocket bending, folding, interference, or the like, deteriorating the filter performance, may be circumvented.
It should be noted that the support elements abutting both sides of the respective filter pocket of the filter unit may be structurally different, i.e. one embodiment may be that for one side of each filter, the support elements may be bars, whereas for the other side, the support elements may be meshes.
The support elements of the pocket filter assembly may symmetrically abut the sides of the respective one filter pocket of the filter unit. This may especially be the case when pocket filters are cone-shaped, pyramid-shaped, or the like. As another example, the support elements of the pocket filter assembly may instead asymmetrically abut the sides of the respective filter pocket of the filter unit. This embodiment could be advantageous in cases when supplementary support is needed for the filter pockets of the filter unit. As an example, if the mounting of the pocket filter assembly is provided such that there is an angle between the depths of the filter pockets of the filter unit and the direction of the gas or air flow, a supplementary support may be needed on the downstream sides of the filter pockets.
According to an embodiment of the present invention, the support elements may constitute a framework structure comprising a plurality of pairs of v-shaped bars abutting the sides of the respective one filter pocket of the filter unit, the framework structure further comprising supplementary bars to substantially fix the positions of the v-shaped bars of the framework structure. This arrangement contributes to the stability of the pocket filter assembly at gas turbine operation.
Here, by the expression "framework structure", it is meant a
constructional system or structure that provides a support and/or strength to the filter pockets of the filter unit.
Furthermore, in this context, the framework structure provided in the filter pocket assembly should still ensure a permeability of air or gas flow through the pocket filter assembly such to provide a satisfactory filter functionality.
In other embodiments of the present invention, the plurality of v-shaped bars may instead be cone-shaped, pyramid-shaped, or the like. Furthermore, the supplementary bars may instead be supplementary grids, meshes, or the like, such to substantially fix the positions of the bars of the framework structure.
According to an embodiment of the invention, the filter unit is provided on a first frame structure, the pre-filter unit is provided on a second frame structure, the framework structure constitutes a constituent unit, the filter unit is inserted into the framework structure, the pre-filter unit is inserted into the filter unit, and wherein the respective units are releasably connected to one another. This arrangement of the pocket filter assembly is advantageous e.g. when the filter pockets of the pre-filter unit are inserted within the filter pockets of the filter unit. This is realized as the second frame structure releasably connected to the first frame structure provides a relative
positioning of the pre-filter unit and the filter unit such as to simplify an insertion of the pockets of the pre-filter unit within the filter pockets of the filter unit.
The frame structures also provide an improved stability of the pocket filter assembly at operation, as the frame structures enable an improved relative positioning of the filter pockets of the pre-filter unit and the filter unit.
The attachment of the second frame structure to the first frame structure may be provided by locking elements, wherein e.g. apertures or recesses may be provided on the first frame structure, while e.g. projections are provided on the second frame structure, or vice versa. The material of the frame structures may be any material providing a rigid structure of the frames such as metal, plastics, or the like. Advantageously, the frame structures may be formed by galvanized steel plates.
Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. Persons skilled in the art realize that different features of the present invention can be combined to create embodiments other than those described in the following. BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects of the present invention will now be described more in detail, with reference to the appended drawings.
Figure 1 shows a profile view of a filter unit according to an
exemplifying embodiment of the invention.
Figure 2 shows a perspective view of a filter unit according to an exemplifying embodiment of the invention.
Figure 3 shows a side view of a filter unit according to an exemplifying embodiment of the invention.
Figure 4 shows a perspective view of a filter unit according to an exemplifying embodiment of the invention.
Figure 5 shows a perspective view of a pre-filter unit according to an exemplifying embodiment of the invention.
Figure 6 shows a perspective view of a pocket filter assembly according to an exemplifying embodiment of the invention.
DETAILED DESCRIPTION
In the following description, the present invention is described with reference to a pocket filter assembly for removing particles from an air or gas flow.
Figure 1 shows a profile view of a pocket filter assembly 1 comprising a filter unit 2 having six filter pockets 3. The filter pockets 3 are arranged in parallel, wherein the filter pockets 3 have flexible sides 4 facing each other.
The profile view of the figure is in a direction perpendicular to an axis parallel to the elongated filter pockets 3 and perpendicular to the direction of the air or gas flow 5. The filter pockets 3 are elongated substantially in the downstream direction of the air or gas flow 5. The fabrication of the filter pockets 3 result in welds 6, elongated on the sides of the filter pockets 3.
In the figure, the downstream direction of the air or gas flow 5 is defined from right to left, i.e. the flow 5 enters the filter pockets 3 of the filter unit 2 through mouths 7 provided on the right hand portion of the filter pockets 3, and the flow 5 flows through the filter pockets 3 and exits the filter unit 2 to the left. The profiles of the filter pockets 3 are v-shaped such that the circumferences of the filter pockets 3 decrease with the depths of the filter pockets 3, in the downstream direction of the air or gas flow 5. Thus, the circumferences of the filter pockets 3 decrease from the mouths 7 to the tips 8 of the filter pockets 3, the tips 8 provided on the left hand portion of the filter pockets 3.
A support structure 9 for supporting the respective one filter pocket 3 of the filter unit 2 is provided in the pocket filter assembly 1 , wherein the support structure 9 comprises support elements 10. For each filter pocket 3, a plurality of support element pairs 11 (only one pair 11 for each filter pocket 3 is shown in the profile view) are provided in v-shapes. The two support elements 10 of each support element pair 11 are separated at the mouth 7 of the respective one filter pocket 3 and extend from the mouths 7 of the respective one filter pocket 3, the support elements 10 abutting both outer, downstream sides of the flexible filter pocket sides 4 of the filter pockets 3 of the filter unit 2.
Eventually, the two support elements 10 of each support element pair 11 come in contact at positions beyond the tips 8 of the filter pockets 3, the tips of the support elements 10 being welded together.
The support element pairs 11 partially enclose a respective one filter pocket 3 of the filter unit 2, and the planes formed by each support element pair 11 are perpendicular to the elongated direction of the filter pockets 3. Thus, the support elements pairs 11 provide a cage-like enclosure of the filter pockets of the filter unit. The filter unit 2 and the support structure 9 for supporting the plurality of filter pockets 3 of the filter unit 2 are releasably connected to a first frame structure 12. The first frame structure 12 is arranged in a plane at the mouths 7 of the filter pockets 3 of the filter unit 2, the plane being perpendicular to the direction of the air or gas flow 5. The filter pockets 3 and the plurality of support element pairs 11 are attached to the first frame structure 12, the filter pockets 3 being equidistantly separated.
A perspective view of the pocket filter assembly 1 shown in figure 1 is shown in figure 2. Each of the six filter pockets 3 of the filter unit 2 is supported by the support structure 9 comprising five pairs 11 of support elements 10. The support element pairs 11 abutting both outer, downstream sides of the flexible filter pocket sides 4, are provided in v-shapes. The openings of the v-shaped support element pairs 11 are provided at the mouths 7 of a respective one filter pocket 3.
Analogously, the closures of the v-shaped support element pairs 11 are provided beyond the tips 8 of the filter pockets 3. The five support element pairs 11 provided for a respective one filter pocket 3 are arranged in parallel, such that the planes formed by each pair of the support element pairs 11 face each other. Furthermore, the element pairs 11 are equidistantly separated. The distance along the width of the filter pocket 3 between the two outermost positioned support element pairs 11 is within the width of the filter pocket 3.
On each of the two outermost positioned filter pockets 3 of the filter unit 2, a supplementary support element 13 is diagonally elongated on the outermost side 4 of the filter pocket 3. The supplementary support element 13 is provided on the outer, downstream side of the five support elements 10 of the five support element pairs 11 of the outermost filter pocket 3. The supplementary support element 13 extends diagonally from the mouth of the outermost filter pocket 3, at one of the outermost positioned support elements 10, to a position 14 where the two support elements 10 of the other outermost positioned support element pair 11 of the five support element pairs 11 come in contact. At this contact, the tips of the support element pair 11 and the supplementary support element 13 are welded together. Furthermore, welds are provided at the intersections of the supplementary support element 13 with the five support elements 10 on the outermost side 4 of the filter pocket 3 such to ensure a stability of the support elements 10.
Figure 3 shows a side view of a filter unit 2 of the pocket filter assembly 1 in a direction perpendicular to an axis parallel to the elongated filter pockets 3 and perpendicular to the downstream direction of the air or gas flow 5. The figure shows the outermost side 4 of a filter pocket 3 of the filter unit 2. The side 4 is substantially rectangular, wherein the long side is substantially elongated in the direction of the air or gas flow 5. The five pairs 11 of support elements 10 of each of the filter pockets 3 (of which pairs 11 only the five outermost support elements 10 are shown) abut both outer, downstream sides of the flexible filter pocket sides 4. The five support element pairs 11 provided for each filter pocket 3 are arranged in parallel, such that the planes formed by each pair of the support element pairs 11 face each other. On each of the two outermost positioned filter pockets 3 of the filter unit 2, the supplementary support element 13 is diagonally elongated on the outermost side 4 of the filter pocket 3.
Figure 4 shows a view of the filter unit 2 of the pocket filter assembly 1 in the downstream direction of the air or gas flow 5. The rectangular-shaped first frame structure 12 comprises four peripheral frame portions 12a, 12b, 12c, 12d and five separating bars 15 extending separately, and in parallel to each other between the two opposite peripheral frame portions 12b, 12d, so as to define six longitudinal mouths 7 of the filter pockets 3. The six filter pockets 3 of the filter unit 2 are provided side by side in the first frame structure 12 and are attached to the first frame structure 12. The filter pockets are further attached to the five separating bars 15.
Figure 5 shows a perspective view of a pre-filter unit 16 of the pocket filter assembly 1 , the pre-filter unit 16 having six filter pockets 17. The filter pockets 16 are elongated substantially in the downstream direction of the air or gas flow entering the filter pockets 17 through mouths provided on the right hand portion of the filter pockets 17. The profiles of the filter pockets 17 are v-shaped such that the circumferences of the filter pockets 17 decrease in the downstream direction of the air or gas flow 5. A rectangular shaped, second frame structure 18 is arranged at the mouths 7 of the filter pockets 17 of the pre-filter unit 16. The filter pockets 17 are releasably connected to the second frame structure 18.
Figure 6 shows a perspective view of a pocket filter assembly 1 comprising a filter unit 2 and a pre-filter unit 16, both as described previously. At least a majority of the filter pockets 17 of the pre-filter unit 16 may be arranged within a respective one of the filter pockets 3 of the filter unit 2. The pre-filter unit 16 is releasably connected to the filter unit 2 for enabling removal therefrom. The outer dimensions of the filter pockets 17 of the pre- filter unit 16 and the inner dimensions of the filter pockets 3 of the filter unit 2 are substantially equal, such that the filter pockets 17 of the pre-filter unit 16 tightly fit within a respective one of the filter pockets 3 of the filter unit 2. The filter pockets 17 of the pre-filter unit 16 are formed to extend within the filter pockets 3 of the filter unit 2 substantially to the bottom thereof. The second frame structure 18 is releasably connected to the first frame structure 12 such that the filter pockets 17 of the pre-filter unit 16 provided on the first frame structure 12 extend within the filter pockets 3 of the filter unit 2 provided on the second frame structure 18.
The attachment of the second frame structure 18 to the first frame structure 12 may be provided by locking elements, wherein e.g. apertures or recesses may be provided on the first frame structure 12, while e.g.
projections are provided on the second frame structure 18, or vice versa.
Even though the invention has been described with reference to specific exemplifying embodiments thereof, many different alterations, modifications and the like will become apparent for those skilled in the art. The described embodiments are therefore not intended to limit the scope of the invention, as defined by the appended claims. For example, any object as described may take on any other geometrical shape. As an example, the rectangular-shaped first frame structure 12 and second frame structure 18 may instead be triangular, circular, quadratic or pentagonal-shaped.
Analogously, the filter pockets 3, 17 of the filter unit 2 and the pre-filter unit 16, respectively, may be cone-shaped, pyramid-shaped or the like. Moreover, any embodiment related to the number of e.g. frame structures 12, 18, filter pockets 3, 17, support elements 10, supplementary support elements 13, or the like may be varied. As an example, there may instead be ten filter pockets 3, 17 of the filter unit 2 and the pre-filter unit 16, respectively, and/or e.g. three pairs of support element pairs 11 to partially enclose a respective one filter pocket 3 of the filter unit 2.
Furthermore, any embodiment related to the placement of the above, or other, elements of the pocket filter assembly 1 , e.g. frame structures 12, 18, filter pockets 3, 17, support elements 10, supplementary support elements 13, or the like may be varied. As an example, there may instead be
supplementary support elements 13 provided on the opposite side of the first frame structure, connecting a plurality of tips 14 of the support element pairs 11 such to increase the stability of the support elements 10.

Claims

CLAIMS 1. A pocket filter assembly for removing particles from an air or gas flow, comprising
a filter unit comprising a plurality of filter pockets arranged in parallel, wherein the filter pockets have flexible sides facing each other,
a pre-filter unit comprising a plurality of filter pockets, wherein each of at least a majority of the filter pockets of the pre-filter unit are arranged within a respective one of the filter pockets of the filter unit, and wherein the pre-filter unit is releasably connected to the filter unit for enabling removal therefrom, and
a support structure for supporting the plurality of filter pockets of the filter unit,
characterized in that
the filter pockets of the pre-filter unit extend within the filter pockets of the filter unit at least a major part of the length thereof, and
the support structure comprises support elements arranged to abut the flexible filter pocket sides of the filter pockets of the filter unit such that
sideway flexing of the filter pockets of the filter unit is hindered, and a free passage for the filter pockets of the pre-filter unit into and out of the filter pockets of the filter unit is formed.
2. The pocket filter assembly as claimed in claim 1 , wherein the filter pockets of the pre-filter unit extend within the filter pockets of the filter unit substantially to the bottom thereof.
3. The pocket filter assembly as claimed in any of the above claims, wherein the outer dimensions of the filter pockets of the pre-filter unit and the inner dimensions of the filter pockets of the filter unit are substantially equal .
4. The pocket filter assembly as claimed in any of the above claims, wherein the support elements are arranged to abut the flexible filter pocket sides of a respective one filter pocket of the filter unit such that the filter pockets arranged in parallel are kept apart.
5. The pocket filter assembly as claimed in claim 4, wherein the support elements abut the outsides of the flexible filter pocket sides of a respective one filter pocket of the filter unit.
6. The pocket filter assembly as claimed in any of the above claims wherein the support elements comprise bars, grids, meshes, or the like.
7. The pocket filter assembly as claimed in claim 5 and 6, wherein the support elements partially enclose a respective one filter pocket of the filter unit, the support elements being v-shaped, cone-shaped, pyramid-shaped or the like.
8. The pocket filter assembly as claimed in any of claims 5-7, wherein the support elements abut both sides of a respective one filter pocket of the filter unit substantially parallel to the depth of the filter pockets of the filter unit.
9. The pocket filter assembly as claimed in any of the above claims, wherein the support elements constitute a framework structure comprising a plurality of pairs of v-shaped bars abutting the sides of a respective one filter pocket of the filter unit, the framework structure further comprising
supplementary bars to substantially fix the positions of the v-shaped bars of the framework structure.
10. The pocket filter assembly as claimed in claim 9, wherein the filter unit is provided on a first frame structure, the pre-filter unit is provided on a second frame structure, the framework structure constitutes a constituent unit, the filter unit is inserted into the framework structure, the pre-filter unit is inserted into the filter unit, and wherein the respective units are releasably connected to one another.
PCT/EP2009/058452 2009-07-03 2009-07-03 Camflo gt wireframe WO2011000437A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/EP2009/058452 WO2011000437A1 (en) 2009-07-03 2009-07-03 Camflo gt wireframe

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2009/058452 WO2011000437A1 (en) 2009-07-03 2009-07-03 Camflo gt wireframe

Publications (1)

Publication Number Publication Date
WO2011000437A1 true WO2011000437A1 (en) 2011-01-06

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WO2013044960A1 (en) 2011-09-29 2013-04-04 Camfil Ab Filter unit
EP2760561A1 (en) * 2011-09-29 2014-08-06 Camfil AB Filter unit
WO2015112743A1 (en) * 2014-01-22 2015-07-30 Bha Altair, Llc Filter bag assembly with rigid mesh for reducing filter pressure loss
US9358488B2 (en) 2013-11-15 2016-06-07 Bha Altair, Llc Gas turbine filtration system with inlet filter orientation assembly
CN106215554A (en) * 2016-08-03 2016-12-14 镇江飞利达电站设备有限公司 Sack cleaner
RU191974U1 (en) * 2019-02-25 2019-08-28 Общество с ограниченной ответственностью "ОКСИ" CHANNEL HOSE FILTER FOR VENTILATION SYSTEMS
CN110755948A (en) * 2019-10-22 2020-02-07 浙江鑫源净化设备有限公司 Purification workshop

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Publication number Priority date Publication date Assignee Title
WO2013044960A1 (en) 2011-09-29 2013-04-04 Camfil Ab Filter unit
WO2013045637A1 (en) 2011-09-29 2013-04-04 Camfil Ab Filter unit
EP2760561A1 (en) * 2011-09-29 2014-08-06 Camfil AB Filter unit
CN104136092A (en) * 2011-09-29 2014-11-05 卡菲尔有限公司 Filter unit
US9522355B2 (en) 2011-09-29 2016-12-20 Camfil Ab Filter unit
US9358488B2 (en) 2013-11-15 2016-06-07 Bha Altair, Llc Gas turbine filtration system with inlet filter orientation assembly
US10323572B2 (en) 2013-11-15 2019-06-18 Bha Altair, Llc Gas turbine filtration system with inlet filter orientation assembly
WO2015112743A1 (en) * 2014-01-22 2015-07-30 Bha Altair, Llc Filter bag assembly with rigid mesh for reducing filter pressure loss
CN106215554A (en) * 2016-08-03 2016-12-14 镇江飞利达电站设备有限公司 Sack cleaner
RU191974U1 (en) * 2019-02-25 2019-08-28 Общество с ограниченной ответственностью "ОКСИ" CHANNEL HOSE FILTER FOR VENTILATION SYSTEMS
CN110755948A (en) * 2019-10-22 2020-02-07 浙江鑫源净化设备有限公司 Purification workshop

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