Patent Application
20230132679
This invention relates to a filter element assembly for removing material that is entrained in a gas stream. The invention also relates to a drainage promoter for a filter element, and a filter element.
Filtration of gas in a compressed gas system is generally required so that the gas is sufficiently clean for a subsequent application or to minimise adverse effects of impurities on components of the system. For example, removal of compressor oil can be required to minimise chemical contamination and accumulation on valves which might lead to malfunction of the valves.
There are many known filter elements for use in a filter assembly in gas systems. Such filter elements generally comprise a cylindrical filtration layer or “coalescing layer” and a cylindrical anti-re-entrainment barrier or “drainage layer” surrounding the filtration layer on the outside of the filter element. The filter elements typically also comprise an end cap having a trough in which the coalescing and drainage layers are retained.
A gas stream enters the tubular filter element through an inlet port and flows through the cylindrical walls of the filter element, generally radially outward from the inside of the filter element to the outside. When the assembly is used to collect liquid droplets in the gas stream (for example which is carried in the stream as an aerosol), the filtration/coalescing layer will cause liquid droplets to coalesce for collection. The coalesced liquid will be carried by the flow of gas to the drainage layer where the liquid can collect. The drainage layer is configured to ensure that re-entry of the liquid into the gas stream is minimised. In use, the liquid will sink to the bottom of the drainage layer, from which it can drain into a reservoir where it can collect prior to disposal. If the liquid does not drain from the drainage layer into the reservoir at least as quickly as liquid is supplied to the drainage layer, the liquid can tend to collect at the base of the drainage layer, where it forms a ‘wet band’ in which the material of the drainage layer is saturated with the liquid.
After prolonged use of the filter element, the depth of the wet band can increase to the extent that gas flowing through the element wall will pass through the wet band. This can increase the resistance to flow of gas through the filter element, and therefore give rise to an increase in pressure drop across the filter element. This can result in increased operating costs. Furthermore, gas flowing through or near a saturated part of the drainage layer can draw droplets of liquid from the drainage layer into the gas flow, thereby re-contaminating the gas as it is discharged from the filter element. It can therefore be seen that significant accumulation of liquid in a wet band can reduce the operating efficiency of the filter element. When the operating efficiency is significantly reduced, the filter element in the filter assembly must be replaced, giving rise to expense and possibly also a requirement for the system in which the assembly is used to be shut down.
Filter elements can be arranged so that they are positioned vertically or horizontally when in use. Traditionally, horizontally placed coalescing filter elements have a standard circular outer drainage layer, or a drainage layer with an elongate tab that is made from the same material as the drainage layer and positioned at the bottom of the element when it is in its deployed position (i.e., at the circumferentially bottom position in a horizontally deployed filter element having a cylindrical shape, viewing along the element).
Reduction of a wet band which can form during use of a filter element would allow more area of the un-wetted filtration material to be used, which would improve the performance of the filter element.
In a first aspect of the present disclosure, there is provided a filter element assembly comprising:
The filter element and the drainage promoter may be capable of being connected to one another, or configured to be connected, so that the filter element and the drainage promoter can be manipulated by a user as a unitary component for positioning in a housing of a filter.
The filter element may be adapted to be disposed, in use, in a horizontal position or orientation. The drainage promoter fin may then be located at a position around a perimeter of the filter element, which is disposed lowermost, in use. Where the filter element is generally circular in shape in cross-section (i.e., a generally cylindrically shaped hollow filter element), the position may be a bottom-most position around a circumference of the element, viewing in a direction along a length of the element in its use position.
The drainage promoter fin may compress the drainage layer of the filter element, which may break the surface tension of the drainage layer material and promote quicker, more efficient drainage of liquid from the drainage layer. An enhanced drainage effect may therefore be provided over conventional horizontally oriented filter elements, as well as over such filter elements comprising a drainage layer including an elongate tab formed of the drainage layer material itself. It may also simplify construction of the filter element, in particular its drainage layer, in contrast to drainage layers comprising such a tab. Further, and in at least some disclosed embodiments, the drainage promoter fin may be capable of being fitted to a standard filter element, without requiring modification to the structure of the element.
The fin may be elongate and may have first and second ends (which may be axial ends). The fin may comprise a base extending along a length of the fin between the ends. The fin may comprise a tip opposite the base and extending along the length of the fin. The tip may define a free edge of the fin. A length dimension of the fin may be greater than a height dimension, the height measured from the base to the tip. The fin may comprise a longitudinal axis extending along a length of the fin between its ends. The base may press into the drainage layer during use. The tip may be spaced away from the base and may define a discharge location from which liquid flowing from the drainage layer can be discharged from the fin. The fin may have a tapered shape in cross-section, which section may be taken transverse (suitably perpendicular) to a longitudinal axis of the fin. This may help to promote the flow of liquid along the fin, for subsequent discharge. The fin may taper in a direction from its base towards its tip. A cross-sectional width of the fin (taken perpendicular to the longitudinal axis) may decrease in a direction towards its tip. The fin may have a height, which may be measured in a direction from the base to the tip. The height may be substantially constant along a length of the fin. The height may vary along a length of the fin, for example the fin (in particular its base) may be curved and may be generally convex.
The fin may be connectable to at least one of the first and second end caps, so that it can be secured to the filter element. The fin may be connectable to both end caps. The fin may extend from one end cap to the other end cap. The fin may be releasably connectable to at least one of the end caps, optionally to both end caps. Providing a releasable connection may allow the drainage promoter fin to be fitted to the filter element following assembly of the filter element, and/or may allow the fin to be used with a further filter element, if the element should become clogged during use and requires replacement.
The fin may comprise at least one connection (or engaging) feature for engaging the filter element, to connect the fin to the element. The connection feature may engage an end cap of the filter element. The fin may comprise a first connection feature for engaging one of the end caps, and a second connection feature for engaging the other one of the end caps. The first and second connection features may be spaced apart along a length of the fin. The fin may comprise a first axial end and a second axial end, and the first and second connection features may be provided on, at or near the respective first and second axial ends.
The filter element may comprise at least one connection (or engaging) feature, which may cooperate with the connection feature on the fin, for connecting the fin to the element. At least one of the end caps may comprise the connection feature. The first end cap may comprise a first connection feature and the second end cap may comprise a second connection feature. The first and second end cap connection features may each be configured to cooperate with the respective first and second connection features of the fin, to connect the fin to the element.
The connection feature of the fin may be a male connection feature and the connection feature of the filter element may be a corresponding female connection feature. The connection feature of the fin may be a female connection feature and the connection feature of the filter element may be a corresponding male connection feature. Where the fin comprises first and second connection features, they may each be a male connection feature, each a female connection feature, or a mixture of male and female connection features may be provided. The first and second connection features of the filter element may therefore each be a female connection feature, each a male connection feature, or a mixture of male and female connection features may be provided, as appropriate.
The female connection feature may define an opening or entrance which is shaped to receive the male connection feature. The male connection feature may be a protrusion or projection, such as a pin, boss, shaft, finger, rib or the like. The female connection feature may be a recess, socket, bore, channel, passage or the like.
The filter element assembly may comprise a pivoting connection between the fin and the filter element. The pivoting connection may be defined by the connection features of the fin and the filter element. One of the fin and the filter element may define a connection feature in the form of a pivot pin or shaft, and the other one of the fin and the filter element may define a pivot mount or socket shaped to receive the pivot pin, so that the fin can pivot relative to the filter element.
The pivot pin and pivot mount may be aligned with, or along, a longitudinal axis of the fin, so that the fin can pivot about the longitudinal axis. The fin may be pivotable between a folded (or installation) position and a deployed (or use) position. The fin may be pivotable generally about or near to its base. When the fin is in the folded position, a tip of the fin may be disposed closer to an outer surface of the drainage layer than when the fin is in its deployed position. A flank of the fin may be disposed proximate the outer surface of the drainage layer when the fin is in its folded position. The ability of the fin to fold in this way may facilitate fitting of the filter element assembly in the filter housing, for example if access to the housing is restricted. The fin may comprise a pivot pin, or a pivot mount at each of its ends, configured to engage a corresponding pivot mount or pivot pin of the filter element. The fin may comprise a pivot pin at both ends, a pivot mount at both ends, or a pin at one end and a mount at the other.
The pivot pin may be disposed transverse (e.g., perpendicular) to the longitudinal axis of the fin. A pair of pivot pin portions may be provided, and axes of the pin portions may be aligned. A first pivot pin portion may extend in a first lateral direction away from the fin, and a second pivot pin portion may extend in a second lateral direction away from the fin. The lateral directions may be transverse to the longitudinal axis of the pin and are suitably perpendicular to it. The pivot pin and the pivot mount/socket may be disposed on a pivot axis which is transverse to the longitudinal axis of the fin, suitably perpendicular to it, when the fin is connected to the filter element. The arrangement may be reversed, with pin portions provided by the filter element (suitably an end cap) and a mount on the fin.
The fin may be pivotable about the pivot axis between a disconnected position in which the fin can be disconnected from the filter element, and a connected position in which the fin is connected to the filter element. In the disconnected position, a longitudinal axis of the fin may be disposed transverse to a longitudinal axis of the filter element. In the connected position, a longitudinal axis of the fin may be disposed substantially parallel to a longitudinal axis of the filter element.
The fin and the filter element may define respective latch features, which may cooperate to provide a latching engagement between the fin and the element. The latch feature on the fin may be spaced along a length of the fin from the pivot pin or pivot mount. The latch feature on the filter element may be provided on one of the end caps. One of the latch features provided by the fin and the filter element may be a resiliently deformable element such as a latch arm, finger, catch or the like, and the other latch feature may be a recess, bore or the like, or an edge surface or face.
The filter element assembly may comprise a sliding connection between the fin and the filter element. The sliding connection may be defined by the connection features of the fin and the filter element. The fin may be translatable relative to the filter element between a disconnected position in which it is not connected to the filter element, and a connected position in which it is connected to the filter element. One of the fin and the filter element may define a connection feature in the form of a protrusion or projection, which may form a key, and which may be a tab, finger or the like. The other one of the fin and the filter element may define a connection feature shaped to receive the protrusion in a sliding fit, may form a keyway, and may be a channel, recess, guide or the like. The key and keyway may have to be aligned for engagement of the connection features. The sliding connection may comprise a restraint which may serve to resist further translation of the fin relative to the filter element (in at least one direction), once the fin has been translated a sufficient distance relative to the filter element and adopted its connected position. The restraint may be a shoulder, which may be provided or defined by the fin and/or the filter element, in particular by their connection features.
The first end cap may comprise a first connection feature for engaging a corresponding first connection feature on the fin. The second end cap may comprise a second connection feature for engaging a corresponding second connection feature on the fin. The respective first connection features of the filter element and the fin, and the respective second connection features of the filter element and the fin, may require to be aligned in order for the fin to be connected to the element. The connection features of the filter element may be aligned along an axis extending along the filter element substantially parallel to its longitudinal axis. At least one of the end caps may comprise a plurality of connection features, which may be spaced around a perimeter of the end cap. This may be advantageous during assembly of the filter element, facilitating rotational alignment of the end cap connection features, so that the fin can subsequently be fitted to the element.
The fin may compress the drainage layer along a majority, or all, of a length of the drainage layer defined or exposed between the first and second end caps of the filter element. This may serve to promote maximum discharge of liquid from the drainage layer, along a length of the drainage layer disposed between the end caps, during use. The fin may be captured between the end caps. The fin may extend at least partly over one or both of the first and second end caps. When the fin is fitted to the filter element, a small gap may be provided between one or both of the end caps and a facing surface of the fin. The facing surface may be in the region of and/or may define the base. The small gap may facilitate sliding connection of the fin to the filter element.
The fin may be configured so that it is connected to the filter element in a press-fit, suitably between the end caps. The fin may be resiliently deformable so that it can be press-fitted to the filter element.
The drainage promoter may comprise at least one drainage element, such as a finger, rib, arm or the like, the drainage element being coupled to the fin and extending in a direction away from the fin. The drainage element may be resilient and/or elastically deformable. The drainage element may extend in a direction around an outer surface of the drainage layer. The drainage element may compress the drainage layer along at least part of its length, which may serve to further promote the drainage of liquid from the drainage layer. The drainage element may extend part way around a perimeter of the outer surface. The drainage element may be disposed transverse to a longitudinal axis of the fin and may be disposed substantially perpendicular to the fin axis. The drainage element may be curved and may have an inner surface with a curvature which substantially matches a curvature of the outer surface of the drainage layer (e.g., for a circular section filter element).
The at least one drainage element may have a base at which it is coupled to the fin and may extend away from the base to a tip, which may define a free end. The at least one drainage element may taper in a direction from the base towards the tip. A width of the at least one drainage element (considered in an axial direction relative to the filter element), and/or a depth (considered in a radial direction relative to the filter element) may reduce in a direction towards the tip. This may help to promote the flow of liquid along the drainage element and on to the fin, for subsequent discharge.
At least one first drainage element may extend from the fin, optionally around the outer surface of the drainage layer in a first direction around the perimeter of the filter element. At least one second drainage element may extend from the fin, optionally around the outer surface of the drainage layer in a second direction around the perimeter of the filter element. The second direction may be opposite to the first direction. The first and second drainage elements may extend from respective first and second flanks of the fin. The drainage elements extending in the different directions may be disposed at common axial positions along a length of the fin or may be axially staggered.
The first and second drainage elements, extending in the different directions, may be configured to together impart a clamping force on the filter element, for connecting the drainage promoter to the element. This may be facilitated by inherent resiliency, or elastic deformability, of the drainage elements. The drainage elements may be considered to form connection features, for connecting the fin to the filter element, and may alternatively be referred to as connection features. The drainage elements may each extend around the perimeter of the filter element to an over-centre position, relative to a central axis of the filter element. This may provide the clamping force. The first and second drainage elements may therefore together encompass more than half of a circumference of a circular filter element.
The first and second drainage elements may together describe a generally cylindrical passage or opening between their inner surfaces, which passage may be shaped to receive the filter element and may have a central axis. The drainage elements may each extend to an over-centre position, relative to the central axis. A space may be defined between the free end of the first drainage element and the free end of the axially adjacent second drainage element. A dimension of the space, measured in a direction perpendicular to the longitudinal axis of the filter element, may be smaller than a diameter (or width as appropriate) of the filter element. This may provide the clamping force.
The drainage promoter may be connectable to the filter element at a location between the first and second end caps. The drainage promoter may be connectable to the drainage layer of the filter element. The drainage promoter may comprise at least one connecting component which can engage the drainage layer, to connect the fin to the filter element. The connecting component may be a strap or tie, which may extend from the fin and around at least part of a perimeter of the drainage layer. The strap or tie may be provided separately and may be connectable to the fin to secure it to the filter element, for example by passing through a locating aperture in the fin and around the discharge layer. In a variation, a strap may be connectable to an end cap, by passing around a perimeter of the cap.
The strap may comprise a first strap portion extending in a first direction away from the fin and around part of a perimeter of the drainage layer. The strap may comprise a second strap portion extending in a second direction away from the fin and around part of a perimeter of the drainage layer, which second direction may be opposite to the first direction. The first and second strap portions may be adapted to be coupled together to connect the fin to the filter element. The first and second strap portions may comprise respective connection features for coupling them together. One of the strap portions may comprise a male connection feature such as a button or stud, and the other one of the strap portions may comprise a female connection feature such as an aperture, the aperture receiving the button in a press fit. The strap portions may carry other connection features, such as zip-tie structures. The first and second strap portions may together encircle the drainage layer when coupled together.
The strap may extend from the fin around substantially the entire perimeter of the drainage layer. The strap may have a free end which is adapted to be coupled to the fin so that the strap encircles the drainage layer, to connect the fin to the filter element.
A first strap may be provided at a first axial location along a length of the fin, and a second strap may be provided which is at a second axial location along the length of the fin. The provision of two straps may provide a secure connection of the fin to the filter element. Further such straps may be provided if desired, which may depend on factors including dimensions of the filter element.
The drainage promoter may be connectable to the drainage layer of the filter element via connection features of the type described as drainage elements above. The connection features may then optionally have a drainage function as described. The drainage promoter may comprise a first part defining a first part of the fin and at least one drainage/connection element, and a second part defining a second part of the fin and at least one drainage/connection element. The first and second fin parts may be adapted to be coupled together to define the drainage promoter. This may facilitate fitting of the drainage promoter to the filter element, in particular where it is fitted to the drainage layer.
Reference is made in this document to a fin which compresses a drainage layer of a filter element along its length. It will be understood that the fin will not necessarily compress the drainage layer along its entire length, and thus that a compressive effect of the fin on the drainage layer may occur along only a part of the length of the fin. The fin may overlap the drainage layer along a part of its length, and a compressive effect may be provided along the part which overlaps the drainage layer, and optionally the entire part which overlaps.
In a second aspect of the present disclosure, there is provided a drainage promoter which can be connected to a filter element, the drainage promoter comprising:
The fin may be releasably connectable to the end caps. The first and second connection features may be adapted to cooperate with corresponding connection features on the end caps. The connection features may be male connection features adapted to cooperate with corresponding female connection features on the end caps. The connection features may be female connection features adapted to cooperate with corresponding male connection features on the end caps. One of the connection features may be a male feature and the other a female feature.
One of the first and second connection features may be a pivoting connection feature, providing a pivoting connection between the fin and the end cap. This may facilitate pivoting movement of the fin relative to the filter element, between a position where an axis of the fin is transverse to a longitudinal axis of the filter element, and a position where the fin axis is substantially parallel to the filter element axis. At least one of the first and second connection features may define a latch feature, which may provide a latching engagement between the fin and the end cap.
The first and second connection features may both be pivoting connection features, providing a pivoting connection between the fin and the end cap. This may facilitate pivoting movement of the fin relative to the filter element, about a pivot axis defined by or parallel to a longitudinal axis of the fin. In this way, the fin may be pivoted between a folded (or installation) position and a deployed (or use) position.
The first and second connection features may be adapted to provide a sliding connection between the fin and the end caps.
In a third aspect of the present disclosure, there is provided a drainage promoter which can be connected to a filter element, the drainage promoter comprising:
The drainage promoter may be connectable to the filter element at a location between the first and second end caps.
The connecting component may be a strap or tie which extends from the fin and around at least part of a perimeter of the drainage layer.
The strap may comprise a first strap portion extending in a first direction away from the fin and around part of a perimeter of the drainage layer. The strap may comprise a second strap portion extending in a second direction away from the fin and around part of a perimeter of the drainage layer, which second direction may be opposite to the first direction. The first and second strap portions may be adapted to be coupled together to connect the fin to the filter element.
The strap may extend from the fin around substantially the entire perimeter of the drainage layer and may have a free end which is adapted to be coupled to the fin so that the strap can encircle the drainage layer, and connect the fin to the filter element.
The connecting component may take the form of a resilient or elastically deformable rib, finger or the like, which may be coupled to the fin and extend in a direction away from the fin. The connecting component may extend, in use, in a direction around an outer surface of the drainage layer. The connecting component may be disposed transverse to a longitudinal axis of the fin and may be disposed substantially perpendicular to the fin axis.
The connecting component may be curved and may have an inner surface with a curvature which substantially matches a curvature of an outer surface of the filter element drainage layer (for a circular section filter element).
At least one first connecting component may extend from the fin in a first direction. At least one second connecting component may extend from the fin in a second direction, which may be opposite to the first direction. The first and second connecting components extending in the different directions may be configured to together impart a clamping force on the drainage layer of the filter element, for connecting the drainage promoter to the element. The connecting components may describe a generally cylindrical passage or space between inner surfaces of the components, which passage may be shaped to receive the filter element, the passage having a central axis. The connecting components may each extend to an over-centre position, relative to the central axis. This may provide the clamping force.
In a fourth aspect of the present disclosure, there is provided a drainage promoter which can be connected to a filter element, the drainage promoter comprising:
The at least one drainage element may extend, in use, in a direction around an outer surface of the drainage layer. The at least one drainage element may compress the drainage layer along at least part of its length, which may serve to further promote the drainage of liquid from the drainage layer. The at least one drainage element may extend part way around a perimeter of the outer surface. The at least one drainage element may be disposed substantially perpendicular to the fin axis.
The drainage promoters of the second to fourth aspects may be connectable to the filter element so that, in use, the filter element and the drainage promoter can be manipulated by a user as a unitary component for positioning in a housing of a filter.
The drainage promoters defined in the second to fourth aspects, including the fins forming part of the drainage promoters, may have any of the further features of the drainage promoters defined elsewhere in this document, particularly in or with reference to the filter element assembly of the first aspect.
In a fifth aspect of the present disclosure, there is provided a method of improving drainage of liquid from a drainage layer of an existing filter element, the method comprising fitting a drainage promoter according to the third or fourth aspect of the present disclosure to the drainage layer of the filter element.
Further features of the method may be derived from the text set out elsewhere in this document.
In further aspects of the present disclosure, filter element assemblies may be provided comprising a filter element and a drainage promoter according to any one of the second, third or fourth aspects.
The filter element may be for location in a housing of a filter, comprising a wall of a filtration medium which defines a hollow space, for a gas stream to flow from the space through the wall to be filtered, the filtration medium including a filtration layer, and a drainage layer located outside the filtration layer in which liquid separated from the gas stream can collect, and first and second end caps at opposite ends of the wall, one of the end caps including a port for a gas stream which communicates with the space within the wall.
In a further aspect of the present disclosure, there is provided a filter element assembly comprising:
The filter element and the drainage promoter may be configured to be manipulated by a user as a unitary component for positioning in a housing of a filter.
The filter element and/or the drainage promoter may have any of the further features defined elsewhere in this document, particularly in or with reference to the first aspect.
In a further aspect of the present disclosure, there is provided a filter element for location in a housing of a filter, the filter element comprising:
The at least one connection feature may be provided on one of the first and second end caps. A connection feature may be provided on both of the end caps. The first end cap may comprise a first connection feature and the second end cap may comprise a second connection feature. The first and second end cap connection features may each be configured to cooperate with respective first and second connection features of the drainage promoter fin, to connect the fin to the element.
The filter element may have any of the further features defined elsewhere in this document, particularly in or with reference to the first aspect. In particular, the at least one connection feature of the filter element may have any of the further features defined in, or in relation to, the first aspect.
Filter element assemblies, drainage promoters, filter elements and a method of improving drainage of liquid from a drainage layer of an existing filter element are defined in the appended claims.
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
Turning firstly to
In use, and as is well known in the field of fluid filters, the filter element assembly 10 is located in a filter 2, as shown in the cross-sectional view of
The filter element assembly 10 comprises a filter element 12, and a drainage promoter, which is indicated by reference numeral 14. As best shown in
The material for the filtration medium in the filtration layer 20 of the filter element 12 will be selected according to the nature of the gas that is to be filtered, the nature of the contaminants (liquid droplets, aerosols, solid particles etc.) to be filtered from the gas, the pressure differential across the filter and so on. Such materials are known, including those used by Parker Domnick Hunter in products which are available under the trademark OIL-X. Suitable materials include, but are not restricted to, borosilicate and other glass fibres, activated carbon minerals, activated silica materials and so on.
The filtration layer 20 can be made from woven fibres. However, as will be appreciated, the filtration layer can be made from sheets of non-woven fibres. For example, a microfibre filtration layer made from fine organic or inorganic fibres may be employed. A coarser fibre layer may be fitted on the inside of a microfibre filtration layer, which may protect a microfibre filtration layer from gross pollution. The filtration layer 20 may comprise a layer of a material which has been folded so that it is fluted (or pleated). This can increase the surface area of the filtration layer 20 through which gas flowing through the filter element 12 will pass. This can also help to increase the rigidity of the filtration layer 20.
The drainage layer 22 comprises a material that is capable of retaining liquid that has been coalesced by the filtration layer 20 and is carried to the drainage layer by the gas stream that flows through the drainage layer. The drainage layer 22 will generally be porous and made from a material which encourages flow of coalesced liquid towards the base of the filter element 12. Factors affecting the drainage characteristics may include pore size and structure, and the material of the drainage layer 22, including for example the surface energy of liquid which is in contact with the material. Materials suitable for use in the drainage layer are used in similar products sold by Parker Domnick Hunter under the trade mark OIL-X. Suitable materials include open-celled foam plastics, felted fabric material, expanded foam materials, woven and non-woven materials.
The filter element 12 also comprises first and second end caps 24 and 26 at opposite ends of the wall 16, the first end cap including a port 28 for the gas stream to flow into the filter element from the filter head port 9, the filter port 28 communicating with the space 18 within the wall. In normal use of the filter, the filter element 12 will be substantially horizontally oriented as shown in
Perforated tubular supports 30 and 32, typically of a metal or metal alloy material, are secured to the end caps 24 and 26, and serve for securing both the filtration layer 20 and the drainage layer 22 to the end caps and separating the different layers. As is well known in the field of the invention, this is suitably achieved by ‘potting’ the supports 30 and 32, and the filtration and drainage layers 20 and 22, within annular channels 34 and 36 defined by the end caps 24 and 26, using an adhesive such as an epoxy-based adhesive.
The filter head comprises a flow conduit 33 which defines the inlet port 9 and serves to direct a gas stream entering the filter head into the filter element 12 through its inlet port 28, so that contaminants in the gas stream can be removed. The filter may have a wide range of uses but may have a particular use in removing contaminants from a gas stream such as a compressed or vacuum gas stream which is to be used in an industrial application, to remove residual oil from a compressor used to pressurise the gas.
The first end cap 22 of the filter element 11 comprises a seal in the form of an O-ring 37 (
The ‘clean’ gas stream exiting the drainage layer 22 flows out through an external surface 44 of the filter element 12 (defined by the drainage layer 22) and into the chamber 3, before passing to an outlet conduit 47 of the filter housing 4. The gas stream exiting the filter 2 flows on to a downstream location.
The filter element assembly 10 of the present disclosure also comprises the drainage promoter 14. The drainage promoter 14 is shown separately in the front and end views of
The fin 46 is elongate, having first and second axial ends 48 and 50. The fin 46 also comprises a base 52 which extends along a length of the fin between its axial ends 48 and 50, and a tip 54 which defines a free edge of the fin. The tip 54 is disposed opposite the base 52, and similarly extends along the length of the fin 46. A length dimension of the fin 46 measured between its two ends 48 and 50 is greater than a height dimension, measured from the base 52 to the tip 54. In the illustrated embodiment, the height dimension is substantially constant along the length of the fin 46. However, the height may vary along a length of the fin 46, for example the fin (in particular its base 52) may be curved and may be generally convex.
As discussed above, during use, the fin 46 presses into the drainage layer 22. This is best shown in the cross-sectional view of
The fin 46 is releasably connectable to the filter element at its first and second end caps 24 and 26. Releasably connecting the fin 46 to the filter element 12 allows the drainage promoter to be fitted to the filter element following assembly of the element. It may also allow the drainage promoter 14 to be used with a further filter element, for example if the existing filter element in the filter 2 becomes clogged and requires replacement.
In the illustrated embodiment, the fin 46 comprises first and second connection features 58 and 60 at its first and second axial ends 48 and 50, which serve for connecting the fin to the filter element 12. The first and second connection features 58 and 60 each take the form of a male feature, in particular a protrusion or projection defining a pivot pin, as best shown in
The pins 58 and 60, and the sockets 62 and 64, together provide a pivoting connection between the fin 46 and the filter element 12. The pins 58 and 60 can rotate within the sockets 62 and 64, so that the fin 46 can be pivoted between a folded or installation position, and a deployed or used position. Reference is made here to
As can best be appreciated from
Fitting of the fin 46 to the filter element 12 is shown in
Although the fin 46 can be fitted to the filter element 12 by locating the fin at a transverse angle relative to the filter element, the sockets 62 and 64 on the end caps 24 and 26, and in particular their lips 70 and 72, may be dimensioned so that the fin 46 can be press-fitted to both sockets at the same time. This is shown in
The fin 46 will typically be located in its folded position during installation of the filter element assembly 10 in a filter housing. Following location of the filter element assembly 10 in the housing with the fin disposed at the bottom of the element (considered in a circumferential sense and viewing along the assembly), the fin 46 can be manually rotated towards its deployed position, in which a transverse axis 74 of the fin (
As discussed above, the drainage promoter fin 46 may be of a polymeric material, and may be moulded, for example injection moulded. Suitable materials may include Nylon, ABS (Acrylonitrile Butadiene Styrene), Polypropylene and Acetal (POM, PolyOxyMethylene). Constructing the fin 46 from such materials may provide it with sufficient resilience/elastic deformability for it to be fitted to the filter element 12. Other materials and manufacturing techniques may however be suitable, including die casting using an aluminium or zinc alloy, for example.
In the illustrated embodiment, the fin 46 includes pivot pins 58 and 60, and pivot mounts 62 and 64 are provided on the filter element 12. It will be understood however that this arrangement may be reversed so that the fin 46 is provided with mounts, and the filter element with pivot pins. Equally, the fin 46 may be provided with one pivot pin and one pivot mount, for engaging a corresponding mount and pin on the filter element 12.
As discussed above, the drainage promoter 14 can readily be fitted to the filter element 12 and facilitates drainage of liquid contaminants from the gas stream flowing through the filter. The drainage promoter fin 46 is fitted to the end caps 24 and 26 of the filter element 12, which must carry appropriate fittings such as the pivot sockets 62 and 64. Dedicated end caps will therefore need to be manufactured, although it is conceivable that existing filter elements could be modified by mounting additional structure on its end caps, providing mountings for the connection features on the fin 46.
Turning now to
The filter element 12a is of substantially the same construction as the filter element 12 shown in
The filter element assembly 10a is also shown in the end views of
In this embodiment, the drainage promoter 14a again comprises a fin 46a which is releasably connectable to the filter element 12a. The fin 46a is pivotable relative to the filter element 12a for connecting it to the element, the fin being shown in a connected position in
The filter element assembly 10a of
In this embodiment, a pivoting connection is provided between the fin 46a and the filter element 12a which facilitates fitting of the fin to the filter element. The fin 46a has a first axial end 48a and a second axial end 50a. A first connection feature 58a is provided at the first axial end 48a, which is a male connection feature in the form of a pivot pin. The male connection feature 58a in fact comprises first and second pivot pin portions 76 and 78, which are generally cylindrical and have rounded heads. The pivot pin portions 76 and 78 are aligned along a transverse axis 80, which is disposed substantially perpendicular to a longitudinal axis 56a of the fin 46a. The first pivot pin portion 76 extends in a first lateral direction away from the longitudinal axis 56a, and the second pivot pin portion 78 in a second lateral direction.
The filter element end cap 24a comprises a first connection feature 62a in the form of a pivot socket or mount, which is a female feature that is shaped to receive the male connection feature defined by the pivot pin portions 76 and 78 on the fin 46a. The female pivot mount 62a on the first end cap 24a is best shown in the enlarged perspective detail view of
The fin 46a is connected to the filter element 12a by aligning the pivot pin portions 76 and 78 with the channel 82, as shown in
Referring to
In the illustrated embodiment, the latch feature 60a on the fin 46a comprises a resiliently deformable latch arm 92 having a latch tooth 94. The latch feature 64a on the end cap 26a comprises a recess 96 which the latch tooth 94 of the latch arm 92 can engage in order to secure the fin 46a to the end cap 26a. A plurality of such recesses 96 may be provided in the end cap 26a, as shown in the end view of
When the fin 46a is pivoted from its disconnected position of
The fin 46a also includes a recess 100 at its second axial end 50a, the recess being shaped to receive an outer peripheral portion 102 of the end cap 26a. When the peripheral portion 102 is located in the recess 100, the fin 46a is securely connected to the end cap 26a, constrained between end faces of the recess. A further resilient latch tooth 104 on the fin 46a snaps over an inner peripheral surface 106 of the end cap 26a, to provide an additional restraint against separation of the fin 46a from the filter element 12a. Engagement of the second axial end 50a of the fin 46a to the end cap 26a also acts to maintain engagement between the first axial end 48a of the fin and the first end cap 24a, because it prevents movement of the pivot pin portions 76 and 78 out of the channel 82 defined between the arms 84. When fitted to the filter element 12a, the fin 46a extends over the second end cap 46a, and partly over the first end cap 24a. A portion of the fin 46a including its base 52a is disposed between the end caps 24a and 26a and spans the distance between the end caps.
It will be understood that the orientation of the fin 46a relative to the filter element 12a may be reversed, with the pivoting connection provided at the second end cap 26a, and the latching connection at the first end cap 24a.
Turning now to
The filter element 12b is of substantially the same construction as the filter element 12 shown in
The filter element assembly 10b is also shown in the end views of
In this embodiment, a sliding connection is provided between the fin 46b and the filter element 12b, the sliding connection being defined by connection features of the fin and the filter element. The connection features on the fin are shown in more detail in the enlarged front and end views of
The second connection feature 60b on the fin 46b takes the form of a protrusion or projection which defines a key, and which takes the form of an elongate finger. The second connection feature 64b defined by the second end cap 26b defines a keyway in the form of a channel which is shaped to receive the key 60b of the fin 46b in a sliding fit. The key 60b has to be aligned with the keyway 64b in order for the features to be connected. This is best shown in the end view of
The first connection feature 58b on the fin 46b similarly takes the form of a protrusion or projection defining a key. The first connection feature 62b defined by the first end cap 24b defines a keyway which similarly receives the key 58b in a sliding fit. Once again, the key 58b and the keyway 62b must be aligned for connection of the features. A restraint in the form of a shoulder 108 on the fin 46b proximate the key 60b acts to resist further translation of the fin relative to the filter element 12b, once the fin has been translated a sufficient distance relative to the filter element and adopted its connected position.
The key 58b defined by the fin 46b comprises key portions 110 and 112 which are aligned along a transverse axis 80b (
The keyway 64b defined by the second end cap 26b is similarly tapered, as is the key 60b defined by the fin 46b. This acts to restrain the key 60b within the keyway 64b once the fin 46b has been connected to the filter element 12b. The key 60b also has a tapered leading end 128 which assists alignment with the keyway 64b during connection of the fin 46b. The leading end 128 defines a latch tooth 130 which can engage in a circumferential recess 132 (
The keyways 62b and 64b on the end caps 24b and 26b, and the keys 58b and 60b defined by the fin 46b, must be aligned along an axis which is parallel to a longitudinal access 42b of the filter element 12b in order for connection of the fin to the element. The alignment axis is shown in the perspective view of
Fitting of the fin 46b to the filter element 12b is shown in the views of
With the keys and keyways aligned as discussed above, the fin 46b can then be translated in the direction of the arrow G in
As can best be seen from
When fitted to the filter element 12b, the fin 46b extends along the second end cap 26b, and partly over the first end cap 24b. A portion of the fin 46a including its base 52a is disposed between the end caps 24a and 26a and spans a majority of the distance between the end caps.
Turning now to
The filter element 12c and the drainage promoter 14c are in fact of very similar construction to the filter element 12b and the drainage promoter 14b of the filter element assembly 10b shown in
The drainage promoter 14c is shown separately, disconnected from the filter element 12c, in the front, end and perspective views of
A first row or array of drainage elements 164 comprises drainage elements 144, 148, 152, 156 and 160, which each extend from the fin 46c in a first lateral direction, from a first flank 165 of the fin. A second row or array 166 comprises the drainage elements 146, 150, 154, 158 and 162 which each extend from the fin 46c in a second lateral direction, from a second flank 167 of the fin. The drainage elements in the arrays 164 and 166 each extend partway around a circumference of an external surface 44c of the drainage layer 22c when the drainage promoter 14c is fitted to the filter element 12c. The drainage elements 144 to 162 in the two rows 164 and 166 together act to promote drainage of liquid from a wet band or zone 170, which can form during use of the filter element 12c. Accordingly, the drainage element need only extend around part of the circumference of the drainage layer 22c in order to provide the enhanced drainage effect.
The drainage elements 144 to 162 are each disposed transverse to a longitudinal axis 56c of the fin and are suitably disposed substantially perpendicular to the fin axis, as can be seen in
The drainage elements 144 to 162 each have a base at which they are coupled to the fin, a base 174 of the drainage element 146 being shown in
The drainage elements in the first row 164 are axially staggered along a length of the fin 46c relative to the drainage elements in the second row 166. This can best be seen from
Whilst the drainage elements 144 to 162 have been shown on a fin 46c which is a sliding connection to its filter element 12c in the fashion of the fin 46b to the element 12b, it will be understood that similar such drainage elements may be provided on any of the other drainage promoters/fins disclosed in this document. By way of non-limiting example therefore, similar such drainage elements may be provided on the fin 46 of
Turning now to
The filter element 10d is of substantially the same construction as the filter element 12 shown in
The filter element assembly 10d is also shown in the end views of
In this embodiment, the drainage promoter 14d can be connected to a drainage layer 22d of the filter element 12d, rather than to first and second end caps 24d and 26d of the filter element 12d, in the way that the previously described drainage promoters are connected to their respective filter elements. The drainage promoter 14d is connected to the filter element 12d at a location between first and second end caps 24d and 26d of the filter element. A fin 46d of the drainage promoter 14d comprises connection features which serve for connecting the fin directly to the drainage layer 22d. In this case, the connection features take the form of resilient elements which are similar to the drainage elements 144 to 162 forming part of the drainage promoter 14c discussed above.
The drainage promoter 14d is shown separately in the front, end and perspective views of
The connection elements 144d to 162d each have a shape which is substantially similar to the drainage elements 144 to 162, tapering from a base 174d towards a tip 176d, which is shown for the connection element 144d in the end view of
In order to provide the clamping force, the connection elements 144d to 162d each extend from the fin 46d around a circumference of the filter element 12d to an over-centre position, relative to a central longitudinal axis 56d of the filter element 12d. A location of the central axis 56d, and the over-centre positioning of the connection elements 144d to 162d, is shown in the end view of
The drainage promoter 14c described above is typically moulded as a unitary or one-piece component, comprising its fin 46c and drainage features 144 to 162. The drainage promoter 14d can similarly be constructed as a unitary or one-piece structure, which would then require a push-fit of the drainage promoter to the drainage layer 22d. This would require that the space 180 defined between the tips 176 of the connection features 144d to 162d be opened up to pass around the drainage layer 22d, over its diameter to the over-centre position shown in
It may therefore be preferable to construct the drainage promoter 14d as a two-piece structure, to facilitate fitting of the drainage promoter to the filter element 12d. This is best shown in the end view of the drainage promoter 14d in
When fitted to the filter element 12d, the fin 46d is disposed between the end caps 24d and 26d and spans a majority of the distance between the end caps.
Turning now to
The filter element 12e is of substantially the same construction as the filter element 12 shown in
The filter element assembly 10e is also shown in the end views of
The drainage promoter 14e comprises a fin 46e and first and second connection elements 200 and 202 which can engage the drainage layer 22e, to connect the fin to the filter element. In the illustrated embodiment, the connection components 200 and 202 are spaced spart along a length of the fin 46e and are suitably provided at respective first and second axial ends 48e and 50e of the fin 46e. It will be understood however that the connection components 200 and 202 may be provided at alternative locations on the fin 46e, and/or that more than two connection components, or conceivably only a single connection component, may be provided.
The connection components 200 and 202 each take the form of a strap or tie which extends from the fin 46e and around a circumference of the drainage layer 22e. The drainage promoter 14e is shown separately in the front, end and perspective views of
The first strap 200 comprises a first strap portion 204 which extends in a first direction away from the fin 46e and around part of a perimeter of the drainage layer 22e, and a second strap portion 206 which extends in a second opposite direction away from the fin and around a further part of the perimeter of the drainage layer. The first and second strap portions 204 and 206 can be coupled together to connect the fin 46e to the filter element 12e. To this end, the strap portions 204 and 206 comprise respective connection features 205 and 207 which serve for coupling the portions together.
The first strap portion 204 comprises a female connection feature in the form of an aperture 205 formed in a stepped end section 209. The second strap portion 206 comprises a male connection feature in the form of a protrusion such as a button 207, which can be located within the aperture 205 in a press-fit, to secure the strap portions 204 and 206 together. The button 207 may include an enlarged head and may be resiliently deformable for passing through the aperture 205 and securing the strap portions 204 and 206 together. It will be understood that this represents just one option for the way in which the strap portions 204 and 206 can be coupled together. Alternatives can be envisaged, including a zip-tie type structure, a separate mechanical connection, or the use of an adhesive. The second strap 202 comprises similar such first and second strap portions 208 and 210 which also comprise connection features in the form of an aperture 212 and a button 214.
The straps 200 and 202 extend from the fin 46e to encompass the entire circumference of the drainage layer 22e, when their respective strap portions 204/206 and 208/210 are coupled together. In a variation however, a strap may be provided comprising a single portion which substantially encircles the drainage layer 22e, the strap being coupled at one end to the fin 46e and having a free end which can be connected to the fin after encircling the drainage layer. In a further variation, one or more straps may be provided separately, and may be connectable to the fin 46e to secure it to the filter element 12e, for example by passing through a locating aperture in the fin and around the drainage layer (or in an alternative, around an end cap).
Engagement of the strap portions 204, 206 and 208, 210 exerts a clamping force on the drainage layer 22e, causing the fin 46e to press into its external surface 44e, as shown in the longitudinal cross-sectional view of
When fitted to the filter element 12e, the fin 46e is disposed between the end caps 24e and 26e and spans the distance between the end caps.
Drainage promoters of the type disclosed in this document which can be connected to a drainage layer of a filter element (in particular the drainage promoters 14e and 14d) may provide the advantage that they can be connected to filter elements of a standard type, without necessarily requiring any modification to be made to the structure of the filter element, in particular its end caps. These and other drainage promoters disclosed in this document can provide the advantage that they can be removed from the filter element and connected to a further element, say in the situation where the filter element becomes clogged during use and requires replacement. This may provide material and cost benefits.
Various modifications may be made to the foregoing without departing from the spirit or scope of the present invention.
Numerous different embodiments of drainage promoters and filter elements to which the disclosed drainage promoters can be fitted are disclosed in this document. In further variations, the features of one or more of the disclosed embodiments may be provided in combination. Thus, for example, combinations of sliding and pivoting connection features, and connection features involving connection to a drainage layer rather than end caps of a filter element, may be provided in combination in further embodiments.
In each embodiment of filter element assembly disclosed in this document, either of the first and second end caps may comprise a port for the entry of gas into the filter element. In relevant embodiments, the fin may be connected differently to end caps of the filter element, for example in the embodiment of
Reference is generally made in this document to a filter element comprising a wall of a filtration medium which defines a hollow space for a gas stream to flow from the space through the wall to be filtered, and a drainage layer located outside the filtration layer in which liquid separated from the gas stream can collect, as well as to a drainage promoter which compresses the drainage layer to promote drainage of liquid which has collected in the drainage layer. Reference may however be made generally to a fluid stream (which may not specifically be a gas), and to the drainage of fluid (which may not specifically be a liquid) which has collected in the drainage layer. The fluid which is collected in the drainage layer may have been filtered from the fluid stream flowing through the wall of the filter element. The fluid stream may therefore comprise a first fluid and at least one further fluid, which further fluid may collect in the drainage layer.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2003117.5 | Mar 2020 | GB | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2021/055441 | Mar 2021 | US |
| Child | 17899029 | US |
