US20230132679A1

US20230132679A1 - Filter Element Assembly

Info

Publication number: US20230132679A1
Application number: US17/899,029
Authority: US
Inventors: Kenneth Wright
Original assignee: Parker Hannifin Manufacturing UK Ltd
Current assignee: Parker Hannifin Manufacturing UK Ltd
Priority date: 2020-03-04
Filing date: 2022-08-30
Publication date: 2023-05-04
Also published as: WO2021175978A3; CN115515698A; GB202003117D0; WO2021175978A2; EP4114550A2; US20220410053A1; EP4194074A1; EP4114551A1; CN115515697A; WO2021175980A1

Abstract

A filter element assembly (10) is disclosed comprising: a filter element (12) for location in a housing (4) of a filter (2), comprising a wall (16) of a filtration medium which defines a hollow space (18), for a gas stream to flow from the space through the wall, the filtration medium including a filtration layer (20), and a drainage layer (22) located outside the filtration layer, first (24) and second (26) end caps at opposite ends of the wall, one including a port (28) for a gas stream which communicates with the space; and a drainage promoter (14) comprising a fin (46) which can be fitted to the filter element so that it extends along the filter element substantially an entire distance between the first and second end caps, the fin compressing the drainage layer along its length to promote drainage of liquid which has collected in the drainage layer.

Description

TECHNICAL FIELD

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.

BACKGROUND

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.

SUMMARY

In a first aspect of the present disclosure, there is provided a filter element assembly comprising:

- a. a filter element 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; and
- b. a drainage promoter comprising a fin which can be fitted/configured to be connected to the filter element so that it extends along the filter element substantially an entire distance between the first and second end caps, the fin compressing the drainage layer along its length to promote drainage of liquid which has collected in the drainage layer.

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:

- a. at least one fin which can be fitted to the filter element so that it extends along the filter element substantially an entire distance between first and second end caps of the filter element, to compress a drainage layer of the filter element along its length and promote drainage of liquid which has collected in the drainage layer;
- b. in which the fin comprises a first connection feature for engaging the first end cap of the filter element, and a second connection feature for engaging the second end cap of the filter element, for connecting the fin to the filter element.

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:

- a. at least one fin which can be fitted to the filter element so that it extends along the filter element substantially an entire distance between the first and second end caps, to compress a drainage layer of the filter element along its length and promote drainage of liquid which has collected in the drainage layer; and
- b. at least one connecting component which can engage the drainage layer to connect the fin to the filter element.

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:

- a. at least one fin which can be fitted to the filter element so that it extends along the filter element substantially an entire distance between the first and second end caps, to compress a drainage layer of the filter element along its length and promote drainage of liquid which has collected in the drainage layer, the fin having first and second axial ends and a longitudinal axis extending along the fin between its axial ends; and
- b. at least one drainage element coupled to the fin and extending in a direction away from the fin, transverse to its longitudinal axis.

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:

- a. a filter element 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; and
- b. a drainage promoter connected to the filter element so that it extends along the filter element substantially an entire distance between the first and second end caps, the fin compressing the drainage layer along its length to promote drainage of liquid which has collected in the drainage layer.

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:

- a. 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;
- b. 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; and
- c. at least one connection feature configured to cooperate with a connection feature on a drainage promotor fin, for connecting the filter element to the drainage promotor fin.

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.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a front view of a filter element assembly in accordance with an embodiment of the present disclosure;

FIG. 1A is a longitudinal cross-sectional view of a filter comprising the filter element assembly of FIG. 1 , drawn to a smaller scale;

FIG. 2 is an end view of the filter element assembly shown in FIG. 1 , taken in the direction of the arrow A in FIG. 1 ;

FIG. 3 is an end view of the filter element assembly shown in FIG. 1 , taken in the direction of the arrow B in FIG. 1 ;

FIG. 4 is a longitudinal cross-sectional view of the filter element assembly shown in FIG. 1 ;

FIG. 5 is a front view of a drainage promoter forming part of the filter element assembly shown in FIG. 1 ;

FIG. 6 is an end view of a drainage promoter forming part of the filter element assembly shown in FIG. 1 ;

FIG. 7 is a perspective view of a drainage promoter forming part of the filter element assembly shown in FIG. 1

FIG. 8 is a perspective view of the filter element assembly shown in FIG. 1 , drawn to a smaller scale;

FIG. 9 is an end view of the filter element assembly, drawn to the smaller scale of FIG. 8 , and showing fitting of the drainage promoter to a filter element of the assembly;

FIG. 10 is a perspective view of the filter element assembly, drawn to the smaller scale of FIG. 8 , and showing fitting of the drainage promoter to a filter element of the assembly;

FIG. 11 is a front view of a filter element assembly in accordance with another embodiment of the present disclosure;

FIG. 12 is an end view of the filter element assembly shown in FIG. 11 , taken in the direction of the arrow A in FIG. 11 ;

FIG. 13 is an end view of the filter element assembly shown in FIG. 11 , taken in the direction of the arrow B in FIG. 11 ;

FIG. 14 is a perspective view of the filter element assembly shown in FIG. 11 , drawn to a smaller scale;

FIG. 15 is a longitudinal cross-sectional view of the filter element assembly shown in FIG. 11 , drawn to a smaller scale;

FIG. 16 is an end view of the filter element assembly, drawn to the smaller scale of FIG. 14 , and showing fitting of a drainage promoter to a filter element of the assembly;

FIG. 17 is a front view of the drainage promoter forming part of the filter element assembly shown in FIG. 11 ;

FIG. 18 is an end view of the drainage promoter forming part of the filter element assembly shown in FIG. 11 ;

FIG. 19 is a perspective view of the drainage promoter forming part of the filter element assembly shown in FIG. 11 ;

FIG. 20 is an enlarged detail view showing connection features of the filter element and the drainage promoter following connection of the drainage promoter to the filter element;

FIG. 21 is a further enlarged detail view showing connection features of the filter element and the drainage promoter following connection of the drainage promoter to the filter element;

FIG. 22 is a front view of a filter element assembly in accordance with a further embodiment of the present disclosure;

FIG. 23 is an end view of the filter element assembly shown in FIG. 22 , taken in the direction of the arrow A in FIG. 22 ;

FIG. 24 is an end view of the filter element assembly shown in FIG. 22 , taken in the direction of the arrow B in FIG. 22 ;

FIG. 25 is a longitudinal cross-sectional view of the filter element assembly shown in FIG. 22 ;

FIG. 26 is a perspective view of the filter element assembly shown in FIG. 22 , illustrating a drainage promoter being fitted to a filter element of the assembly;

FIG. 26A is a side view of the filter element assembly shown in FIG. 22 , showing a first step fitting of a drainage promoter to a filter element of the assembly;

FIG. 26B is a side view of the filter element assembly shown in FIG. 22 , showing a second step fitting of a drainage promoter to a filter element of the assembly;

FIG. 26C is a side view of the filter element assembly shown in FIG. 22 , showing a third step fitting of a drainage promoter to a filter element of the assembly;

FIG. 27 is a side view of the drainage promoter forming part of the assembly of FIG. 22 ;

FIG. 28 is an end view of the drainage promoter forming part of the assembly of FIG. 22 ;

FIG. 29 is a perspective view of the drainage promoter forming part of the assembly of FIG. 22 ;

FIG. 30 is a front view of a filter element assembly in accordance with a further embodiment of the present disclosure;

FIG. 31 is a front view of a drainage promoter forming part of the filter element assembly shown in FIG. 30 ;

FIG. 32 is an end view of a drainage promoter forming part of the filter element assembly shown in FIG. 30 ;

FIG. 33 is a perspective view of a drainage promoter forming part of the filter element assembly shown in FIG. 30 ;

FIG. 34 is a front view of a filter element assembly in accordance with a further embodiment of the present disclosure;

FIG. 35 is an end view of the filter element assembly shown in FIG. 34 , taken in the direction of the arrow A in FIG. 34 ;

FIG. 36 is an end view of the filter element assembly shown in FIG. 34 , taken in the direction of the arrow B in FIG. 34 ;

FIG. 37 is a perspective view of the filter element assembly shown in FIG. 34 , drawn to a smaller scale;

FIG. 38 is a longitudinal cross-sectional view of the filter element assembly shown in FIG. 34 , drawn to a smaller scale;

FIG. 39 is a front view of a drainage promoter forming part of the filter element assembly shown in FIG. 34 , drawn to a smaller scale;

FIG. 40 is an end view of a drainage promoter forming part of the filter element assembly shown in FIG. 34 , drawn to a smaller scale;

FIG. 41 is a perspective view of a drainage promoter forming part of the filter element assembly shown in FIG. 34 , drawn to a smaller scale;

FIG. 42A is an end view of the filter element assembly of FIG. 34 , shown during fitting of the drainage promoter to the filter element;

FIG. 42B is an end view of the drainage promoter forming part of the filter element assembly of FIG. 34 , showing assembly of the drainage promoter;

FIG. 43 is a front view of a filter element assembly in accordance with a further embodiment of the present disclosure;

FIG. 44 is an end view of the filter element assembly shown in FIG. 43 , taken in the direction of the arrow A in FIG. 43 ;

FIG. 45 is an end view of the filter element assembly shown in FIG. 43 , taken in the direction of the arrow B in FIG. 43 ;

FIG. 46 is a front view of a drainage promoter forming part of the filter element assembly shown in FIG. 43 , drawn to a smaller scale;

FIG. 47 is an end view of a drainage promoter forming part of the filter element assembly shown in FIG. 43 , drawn to a smaller scale;

FIG. 48 is a perspective view of a drainage promoter forming part of the filter element assembly shown in FIG. 43 , drawn to a smaller scale;

FIG. 49 is a front view of the filter element assembly shown in FIG. 43 , shown during fitting of the drainage promoter to a filter element of the assembly, drawn to a smaller scale;

FIG. 50 is an end view of the filter element assembly shown in FIG. 43 , shown during fitting of the drainage promoter to a filter element of the assembly, drawn to a smaller scale;

FIG. 51 is a longitudinal cross-sectional view of the filter element assembly shown in FIG. 43 , drawn to the smaller scale of FIG. 49 and shown following fitting of the drainage promoter to the filter element; and

FIG. 52 is a perspective view of the filter element assembly shown in FIG. 43 , drawn to the smaller scale of FIG. 49 and shown following fitting of the drainage promoter to the filter element.

DETAILED DESCRIPTION

Turning firstly to FIG. 1 , there is shown a front view of a filter element assembly in accordance with an embodiment of the present disclosure, the filter element assembly indicated generally by reference numeral 10. The filter element assembly 10 is also shown in the end views of FIGS. 2 and 3 , taken in the direction of the arrows A and B respectively in FIG. 1 , and the longitudinal cross-sectional view of FIG. 4 , which is drawn to a larger scale.
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 FIG. 1A, drawn to a smaller scale. The filter element assembly 10 is located within a chamber defined by a housing 4 of the filter 2. The housing 4 includes an opening 5 through which the filter element assembly 10 can be inserted into the housing for location in the chamber 3. A cover 6 is then coupled to the housing 4, to secure the filter element assembly 10 in the chamber 3 so that fluid to be filtered can be directed through the filter element assembly 10, from a filter head 7. A tie-rod 8 secures the filter element assembly 10 within the housing 4. Gas to be filtered enters the filter head 7 through a port 9 and flows into the filter element assembly 10 to be filtered.
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 FIG. 4 , the filter element 12 comprises a wall 16 of a filtration medium defining a hollow space 18, for a gas stream to flow from the space through the wall to be filtered. The filtration medium includes a filtration layer 20, and a drainage layer 22 located outside the filtration layer, in which liquid separated from the gas stream can collect. Filter elements having such filtration and drainage layers are well known in the field of fluid filters, and persons skilled in the art will appreciate their general construction and operation during use. Accordingly, the filtration and drainage layers 20 and 22, including their materials and methods of manufacture, will not be described in detail in this document. In general terms however, the filtration and drainage layers 20 and 22 may have the following features.
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 FIG. 1A, so that the first end cap 24 defines a first lateral end of the filter element, and the second end cap 26 defines a second lateral end of the filter element.
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 (FIG. 1A), which is mounted in a groove 38 defined in a tubular wall 40 of the end cap defining the port 28. The O-ring seal 37 serves for sealing the filter element 12 relative to the filter head conduit 33, so that gas entering the head is directed into the filter element. The gas stream entering the filter element 12 flows through its port 28 generally in a direction along an axis 42 of the filter element, and into the space 18. The gas stream containing the contaminants flows from the central space 18 radially outwardly, through the wall 16 of the filter element 12, passing through the filtration layer 20 and the drainage layer 22. The filtration layer 20 serves for filtering out contaminants, which as described above may be residual oil entrained in the gas stream. Oil droplets coalesce and enter the drainage layer 22, building up to form a ‘wet band’ towards a lower part of the drainage layer. The liquid oil in this wet band progressively drains from the lower part of the drainage layer 22 into a sump 43 of the filter housing 4 and can flow out of the sump via a drain 45.
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 FIGS. 5 and 6 , and the perspective view of FIG. 7 . The drainage promoter 14 comprises a fin 46 which can be fitted to the filter element 12 so that it extends along the filter element substantially an entire distance between its first and second end caps 24 and 26, as can be seen for example in FIGS. 1 and 4 . The fin 46 acts to compress the drainage layer 22 of the filter element 12 along its length, to promote drainage of liquid which has collected in the drainage layer. In the exemplary use discussed above, this is oil which has coalesced from the gas flowing through the filter element 12, in the drainage layer 22. The drainage promoter fin 46 compresses the drainage layer 22 of the filter element 12, breaking the surface tension of the drainage layer material and promoting quicker and more deficient drainage of liquid from it. The filter element 12 and the drainage promoter 14 are capable of being connected to one another so that the filter element and the drainage promoter can be manipulated by a user as a unitary component for positioning in the housing 4 of the filter 2.
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 FIG. 4 , the fin base 52 pressing into the drainage layer 22 to break the surface tension and promote drainage of liquid. Liquid flowing from the drainage layer 22 on to the fin 46 flows in a direction from the base 52 towards the tip 54, the tip defining a discharge location from which the liquid can be discharged from the fin into the housing sump 43, as discussed above. The fin 46 has a tapered shape in cross-section, taken in a direction which is perpendicular to a longitudinal axis 56 of the fin. This tapered shape can be best seen in the end and perspective views of FIGS. 6 and 7 . Providing the fin 46 with such a tapered shape helps to promote the flow of liquid along the fin to its tip 54, and subsequent discharge. As can be seen, a cross-sectional width of the fin decreases in a direction away from its base 52 towards its tip 54. The base 52 has a generally rounded profile so as to reduce a likelihood of damaging the material of the drainage layer 22.
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 FIG. 7 . The pivot pins 58 and 60 are generally cylindrically shaped and have respective rounded heads 59 and 61. The filter element 12 comprises corresponding first and second connection features 62 and 64, which cooperate respectively with the first and second connection features 58 and 60 of the fin 46. In the illustrated embodiment, the first and second connection features 62 and 64 of the filter element 12 are provided respectively on the first and second end caps 24 and 26 and are female connection features in the form of a pivot mount or socket which is shaped to receive the pins 58 and 60 of the fin 46. To this end, the sockets are typically circular in shape, defining a cylindrical space which can receive the cylindrical pins 58 and 60.
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 FIGS. 8, 9 and 10 which are a perspective view of the filter element 12, an end view taken in the direction of the arrow B in FIG. 1 , and a front view similar to FIG. 1 , respectively, all drawn to a smaller scale. The fin 46 is shown in its deployed position in FIG. 8 (as well as FIGS. 1 to 4 ). FIG. 9 also shows the fin 46 in its deployed position, as well as the folded position of the fin, which is indicated in the drawing with a broken line 66. The fin 46 can pivot between its folded position 66 and its deployed position in the direction of the arrow C in FIG. 9 . When the fin 46 is in its folded position 66, the tip 54 of the fin is disclosed closer to the external surface 44 of the drainage layer 22 than when the fin is in its deployed position. A flank 68 of the fin is disposed proximate the external surface 44 when the fin is in its folded position. The ability of the fin 46 to fold or pivot in this way can facilitate fitting of the filter element assembly 10 in its filter housing, for example if access to the housing is restricted, such as in a tight or confined space, or if the housing opening 5 is small compared to the filter element assembly 10 with the fin deployed.
As can best be appreciated from FIGS. 5 to 7 , the pivot pins 58 and 60 are aligned along the longitudinal axis 56 of the pin 46, so that the fin pivots about its longitudinal axis when it is moved between its folded and deployed positions. The portion of the fin 46 defining the base 52 extends a certain distance away from the longitudinal axis 56, so that the base 52 presses into the external surface 44 of the drainage layer 22 to compress it, when the fin is pivoted to its deployed position. Shaping the base 58 so that it is rounded as discussed above helps to prevent damage to the drainage layer 22 as the fin 46 pivots between its different positions.
Fitting of the fin 46 to the filter element 12 is shown in FIG. 10 . The fin 46 is typically of a polymeric material and may be resiliently deformable for fitting to the filter element 12. The fin 46 may be fitted by locating one of the pivot pins 58 and 60 in its respective mounting socket 62 or 64 on the filter element 12. This requires that the fin 46 be disposed at an angle relative to the filter element 12, so that its longitudinal axis 56 is transverse to the filter element axis 42. The fin 46 can then be moved to a position in which the other one of the pivot pins 58 and 60 is proximate its mounting socket 62 or 64, and the fin resiliently deformed to a certain extent in order to snap the pivot pin into its socket. This may be achieved by deforming the fin 46 along its length, for example by causing it to adopt a curved shape, and/or the pin itself may be resiliently deformable so that it can pass into the socket. To facilitate fitting of the fin 46, the sockets 62 and 64 on the end caps 24 and 26 may comprise radially outer lips 70 and 72 forming outer wall portions of the sockets, over which the pivot pins 58 and 60 can pass in order to be received in the sockets.
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 FIG. 10 and can be achieved by bringing the fin 46 adjacent to the filter element 12 with the fin axis 56 substantially parallel to the filter element axis 42. The pivot pins 58 and 60 can then be press fitted into the sockets, passing over the lips 70 and 72, this involving a small deformation of the fin 46 to adopt a curved shape, and/or deformation of the pivot pins 58 and 60, as discussed above.
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 (FIG. 6 ) is disposed substantially on a radius of the filter element 12, which radius intersects with its longitudinal axis 42.
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 FIG. 11 , there is shown a front view of a filter element assembly in accordance with another embodiment of the present disclosure, the filter element assembly indicated generally by reference numeral 10 a. The filter element assembly 10 a comprises a filter element 12 a and a drainage promoter 14 a. Like components of the filter element assembly 10 a with the filter element 10 shown in FIGS. 1 to 10 share the same reference numerals, with the addition of the suffix “a”.
The filter element 12 a is of substantially the same construction as the filter element 12 shown in FIGS. 1 to 11 and described above. Accordingly, details of the construction and operation of the filter element 10 a will not be described again in detail, reference instead being made to the discussion of the filter element 12 forming part of the filter element assembly 10 described above. Only substantial differences between the filter element assembly 10 a and the assembly 10 will be described herein. In addition, the filter element assembly 10 a can be located in a housing 4 of a filter 2 in a horizontal orientation in the same way as the filter element assembly 10. Reference will therefore be made to the discussion above concerning the way in which the filter element assembly 10 a is located in a filter housing, and the way in which it operates during use.
The filter element assembly 10 a is also shown in the end views of FIGS. 12 and 13 , taken in the direction of the arrows A and B respectively in FIG. 11 . FIG. 14 is a perspective view, and FIG. 15 a longitudinal cross-sectional view of the filter element assembly 10 a, both drawn to a smaller scale.
In this embodiment, the drainage promoter 14 a again comprises a fin 46 a which is releasably connectable to the filter element 12 a. The fin 46 a is pivotable relative to the filter element 12 a for connecting it to the element, the fin being shown in a connected position in FIGS. 11 to 15 , and in a disconnected position in the side view of FIG. 16 , during fitting of the fin to the filter element. The fin 46 a is also shown separately in the front, end and perspective views of FIGS. 17, 18 and 19 , the end view being taken in the direction of the arrow D in FIG. 17 . The fin 46 a is drawn to the same scale in FIGS. 17 and 19 as it is in FIG. 11 but is shown in a different orientation.
The filter element assembly 10 a of FIGS. 11 to 19 differs from the filter element assembly 10 largely in relation to the way in which the fin 46 a is connected to the filter element 12 a. To this end, both the filter element 12 a, and the fin 46 a, include connection features which are different to those of the respective filter element 12, and fin 46.
In this embodiment, a pivoting connection is provided between the fin 46 a and the filter element 12 a which facilitates fitting of the fin to the filter element. The fin 46 a has a first axial end 48 a and a second axial end 50 a. A first connection feature 58 a is provided at the first axial end 48 a, which is a male connection feature in the form of a pivot pin. The male connection feature 58 a 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 56 a of the fin 46 a. The first pivot pin portion 76 extends in a first lateral direction away from the longitudinal axis 56 a, and the second pivot pin portion 78 in a second lateral direction.
The filter element end cap 24 a comprises a first connection feature 62 a 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 46 a. The female pivot mount 62 a on the first end cap 24 a is best shown in the enlarged perspective detail view of FIG. 20 , as well as the end views of FIGS. 12 and 13 . The connection socket 62 a includes a channel 82 which is shaped to receive the pivot pin portions 76 and 78, the channel being defined by a pair of curved arms 84 which extend from an outer perimeter 86 of the first end cap 24 a. A slot 88 is defined between ends of the two arms 84, which is shaped to receive the fin 46 and communicates with the channel 82. The channel 82 has a closed end 90 (FIG. 20 ), which defines a detent for the pivot pin portions 76 and 78.
The fin 46 a is connected to the filter element 12 a by aligning the pivot pin portions 76 and 78 with the channel 82, as shown in FIG. 13 . The pivot pin portions 76 and 78 can then be translated along the channel 82 until they come to rest at the closed end 90. The fin 46 a is then in the position shown in FIG. 16 and can be pivoted about the transverse axis 80 of the pivot pin portions 76 and 78, by moving the second axial end 50 a of the fin 46 a in the direction of the arrow F in FIG. 16 . The fin 46 a can then be secured to the second end cap 26 a at its second axial end 50 a, to secure the fin to the filter element 12 a.
Referring to FIG. 21 , which is an enlarged detail view of the connection between the fin 46 a and the second end cap 26 a, the fin comprises a second connection feature 60 a, which in this embodiment is a latch feature that provides a latching engagement with the second end cap 26 a. The second end cap 26 a comprises a second connection feature 64 a, and the latch feature 60 a on the fin 46 a engages the latch feature 64 a on the end cap 26 a to secure the fin 46 a to the filter element.
In the illustrated embodiment, the latch feature 60 a on the fin 46 a comprises a resiliently deformable latch arm 92 having a latch tooth 94. The latch feature 64 a on the end cap 26 a comprises a recess 96 which the latch tooth 94 of the latch arm 92 can engage in order to secure the fin 46 a to the end cap 26 a. A plurality of such recesses 96 may be provided in the end cap 26 a, as shown in the end view of FIG. 13 . This may facilitate orientation of the end caps 24 a and 26 a during manufacture of the filter element 12 a, so that the connection features 62 a and 64 a can be aligned for receiving the fin connection features 58 a and 60 a.
When the fin 46 a is pivoted from its disconnected position of FIG. 16 to its connected position of FIG. 21 , the latch arm 92 comes in to contact with a chamfered surface 98 on the end cap 26 a. The latch tooth 94 is similarly chamfered such that application of force to the fin 46 a in the direction F causes the latch arm 92 to deform, so that the latch tooth 94 can pass along the chamfered surface and over an end surface of the end cap 26 a, before latching into the recess 96 as shown in FIG. 21 . The fin 46 a is then connected to the filter element 12 a.
The fin 46 a also includes a recess 100 at its second axial end 50 a, the recess being shaped to receive an outer peripheral portion 102 of the end cap 26 a. When the peripheral portion 102 is located in the recess 100, the fin 46 a is securely connected to the end cap 26 a, constrained between end faces of the recess. A further resilient latch tooth 104 on the fin 46 a snaps over an inner peripheral surface 106 of the end cap 26 a, to provide an additional restraint against separation of the fin 46 a from the filter element 12 a. Engagement of the second axial end 50 a of the fin 46 a to the end cap 26 a also acts to maintain engagement between the first axial end 48 a of the fin and the first end cap 24 a, 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 12 a, the fin 46 a extends over the second end cap 46 a, and partly over the first end cap 24 a. A portion of the fin 46 a including its base 52 a is disposed between the end caps 24 a and 26 a and spans the distance between the end caps.
It will be understood that the orientation of the fin 46 a relative to the filter element 12 a may be reversed, with the pivoting connection provided at the second end cap 26 a, and the latching connection at the first end cap 24 a.
Turning now to FIG. 22 , there is shown a front view of a filter element assembly in accordance with another embodiment of the present disclosure, the filter element assembly indicated generally by reference numeral 10 b. The filter element assembly 10 b comprises a filter element 12 b and a drainage promoter 14 b. Like components of the filter element assembly 10 b with the filter element 10 shown in FIGS. 1 to 10 share the same reference numerals, with the addition of the suffix “b”.
The filter element 12 b is of substantially the same construction as the filter element 12 shown in FIGS. 1 to 11 and described above. Accordingly, details of the construction and operation of the filter element 10 b will not be described again in detail, reference instead being made to the discussion of the filter element 12 forming part of the filter element assembly 10 described above. Only substantial differences between the filter element assembly 10 b and the assembly 10 will be described herein. In addition, the filter element assembly 10 b can be located in a housing 4 of a filter 2 in a horizontal orientation in the same way as the filter element assembly 10. Reference will therefore be made to the discussion above concerning the way in which the filter element assembly 10 b is located in a filter housing 4, and the way in which it operates during use.
The filter element assembly 10 b is also shown in the end views of FIGS. 23 and 24 , taken in the direction of the arrows A and B respectively in FIG. 22 . FIG. 25 is a longitudinal cross-sectional view of the filter element assembly 10 b, and FIG. 26 is a perspective view of the assembly, showing a fin 46 b of its drainage promoter 14 b prior to connection to the filter element 12 b. The fin 46 b is shown in its connected state in FIGS. 22 and 25 , and in its disconnected state in FIG. 26 , as mentioned above. FIGS. 26A, B and C are front views of the filter element assembly 10 b showing successive steps in connection of the fin 46 b to the filter element 12 b.
In this embodiment, a sliding connection is provided between the fin 46 b and the filter element 12 b, 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 FIGS. 27 and 28 , and the perspective view of FIG. 29 , the end view taken in the direction of the arrow D in FIG. 27 . The fin 46 b is translatable relative to the filter element 12 b between its disconnected position and its connected position. The fin 46 b has a first axial end 48 b and a second axial end 50 b. A first connection feature 58 b is provided at the first axial end 48 b, and a second connection feature 60 b at the second axial end 50 b. The filter element 12 b, in particular first and second end caps 24 b and 26 b of the filter element, define corresponding connection features 62 b and 64 b, which cooperate with the respective first and second connection features 58 b and 60 b on the fin 46 b, so that the fin can be connected to the filter element end caps.
The second connection feature 60 b on the fin 46 b 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 64 b defined by the second end cap 26 b defines a keyway in the form of a channel which is shaped to receive the key 60 b of the fin 46 b in a sliding fit. The key 60 b has to be aligned with the keyway 64 b in order for the features to be connected. This is best shown in the end view of FIG. 24 .
The first connection feature 58 b on the fin 46 b similarly takes the form of a protrusion or projection defining a key. The first connection feature 62 b defined by the first end cap 24 b defines a keyway which similarly receives the key 58 b in a sliding fit. Once again, the key 58 b and the keyway 62 b must be aligned for connection of the features. A restraint in the form of a shoulder 108 on the fin 46 b proximate the key 60 b acts to resist further translation of the fin relative to the filter element 12 b, once the fin has been translated a sufficient distance relative to the filter element and adopted its connected position.
The key 58 b defined by the fin 46 b comprises key portions 110 and 112 which are aligned along a transverse axis 80 b (FIG. 28 ) of the fin, the key portion 110 extending in a first lateral direction away from the fin, and the second key portion 112 in a second, opposite lateral direction. The key portions 110 and 112 are shaped to engage within a channel 114 of the keyway 58 b on the first end cap 24 b, which is defined by a pair of arms 116 and 118. The channel 114 tapers in a direction radially outwardly of the filter element 12 b and the key portions 110 and 112 have a corresponding taper. This provides secure engagement of the key portions 110 and 112 within the channel 114 and acts to resist radial separation of the fin 46 b from the first end cap 24 b when connected. Latch teeth 120, 122 on the respective arms 116 and 118 engage on radially outer ledges 124, 126 of the respective key portions 110, 112 to restrain them in the channel 114.
The keyway 64 b defined by the second end cap 26 b is similarly tapered, as is the key 60 b defined by the fin 46 b. This acts to restrain the key 60 b within the keyway 64 b once the fin 46 b has been connected to the filter element 12 b. The key 60 b also has a tapered leading end 128 which assists alignment with the keyway 64 b during connection of the fin 46 b. The leading end 128 defines a latch tooth 130 which can engage in a circumferential recess 132 (FIG. 25 ) defined on a lower end of the second end cap 26 b. This acts to resist sliding movement of the fin 46 b away from its connected position.
The keyways 62 b and 64 b on the end caps 24 b and 26 b, and the keys 58 b and 60 b defined by the fin 46 b, must be aligned along an axis which is parallel to a longitudinal access 42 b of the filter element 12 b in order for connection of the fin to the element. The alignment axis is shown in the perspective view of FIG. 26 and given the reference numeral 134. In use, and once the fin 46 b has been connected to the filter element 12 b, a longitudinal axis 56 b of the fin 46 b resides on the alignment axis 134.
Fitting of the fin 46 b to the filter element 12 b is shown in the views of FIGS. 26A to C. As can be seen from FIG. 26A, a base 52 b of the fin 46 b has an axial length which is slightly smaller than an axial length L₁of the drainage layer 22 b disposed between the filter end caps 24 b and 26 b. This allows the base 52 b to be inserted between the end caps 24 b and 26 b, in contact with the drainage layer 22 b. This is shown in FIG. 26B. The key 60 b is aligned with the keyway 64 b, and the key 58 b with the keyway 62 b, along the axis 134. The base 52 b of the fin 46 b has facing end surfaces, one of which is defined by the shoulder 108, and the other by a shoulder 136 (FIG. 29 ). The key portions 110 and 112 of the key 58 b are spaced along a length of the fin 46 b from the shoulder 136, defining an area 138 which can receive the arms 116 and 118 of the keyway 62 b, so that the fin 46 b can be located between the end caps 24 b and 26 b as shown in FIG. 26B. In this position, the key 60 b is axially spaced from the keyway 64 b on the second end cap 26 b, and the key 58 b is axially spaced from the keyway 62 b on the first end cap 24 b.
With the keys and keyways aligned as discussed above, the fin 46 b can then be translated in the direction of the arrow G in FIG. 26C. This advances the key 60 b into the keyway 64 b, and the key 58 b into the keyway 62 b, so that they are located in their respective positions shown in FIG. 24 and FIG. 23 and described above. The latch tooth 130 engages in the circumferential recess 132 on the second end cap 26 b, and a lip 140 adjacent the shoulder 108 on the fin 46 b engages over an inner peripheral surface 106 b (FIG. 25 ) of the second end cap 26 b. When the fin 46 b is connected to the filter element 12 b, there is a small gap 142 between the shoulder 136 on the fin and the first end cap 24 b. This gap enables fitting of the fin 46 b between the end caps 24 b and 26 b, and the translational movement of the fin between its positions of FIG. 28 and FIG. 29 .
As can best be seen from FIGS. 24 and 26 , the second end cap 26 b in fact comprises a plurality of keyways 64 b, which are spaced around a circumference of the end cap. The provision of such a plurality of keyways 64 b can aid manufacture of the filter element 12 b. In particular and as discussed above, the filtration and drainage layers 20 and 22 of the filter element 12 b, as well as other components such as the perforated support tubes 30 b and 32 b, are potted in the end caps 24 b and 26 b using a suitable adhesive. In order for the fin 46 b to be fitted to the filter element 12 b, the keyway 62 b on the first end cap 24 b must be aligned with a keyway 64 b on the second end cap 26 b. Providing the large number of keyways 64 b spaced around the circumference of the second end cap 26 b can simplify alignment with the keyway 62 b during assembly.
When fitted to the filter element 12 b, the fin 46 b extends along the second end cap 26 b, and partly over the first end cap 24 b. A portion of the fin 46 a including its base 52 a is disposed between the end caps 24 a and 26 a and spans a majority of the distance between the end caps.
Turning now to FIG. 30 , there is shown a front view of a filter element assembly in accordance with another embodiment of the present disclosure, the filter element assembly indicated generally by reference numeral 10 c. The filter element assembly 10 c comprises a filter element 12 c and a drainage promoter 14 c. Like components of the filter element assembly 10 c with the filter element assembly 10 shown in FIGS. 1 to 10 share the same reference numerals, with the addition of the suffix “c”.
The filter element 12 c and the drainage promoter 14 c are in fact of very similar construction to the filter element 12 b and the drainage promoter 14 b of the filter element assembly 10 b shown in FIGS. 22 to 29 and described above. In particular, the drainage promoter 14 c comprises a fin 46 c which is connected to the filter element 12 c in a sliding connection, in the same way as the fin 46 b is fitted to the filter element 12 b. Reference is therefore made to the discussion of FIGS. 22 to 29 concerning the way in which the fin 46 c is fitted to the filter element 12 c.
The drainage promoter 14 c is shown separately, disconnected from the filter element 12 c, in the front, end and perspective views of FIGS. 31, 32 and 33 . The drainage promoter fin 46 c differs from the fin 46 b in that it comprises a plurality of drainage elements 144 to 162, each of which is coupled to the fin 46 c and extends in a direction away from the fin. The drainage elements 144 to 162 each take the form of a finger, rib, arm or the like, and are typically moulded integrally with the fin 46 c. It will be understood however that the drainage elements 144 to 162 may be manufactured separately and subsequently connected to the fin 46 c. The drainage elements 144 to 162 each extend in a direction around an outer surface of a drainage layer 22 c of the filter element 12 c, as shown in FIG. 30 , and act to compress the drainage layer along their lengths, to further promote the drainage of liquid from the drainage layer and on to the fin 46 c.
A first row or array of drainage elements 164 comprises drainage elements 144, 148, 152, 156 and 160, which each extend from the fin 46 c 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 46 c 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 44 c of the drainage layer 22 c when the drainage promoter 14 c is fitted to the filter element 12 c. 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 12 c. Accordingly, the drainage element need only extend around part of the circumference of the drainage layer 22 c in order to provide the enhanced drainage effect.
The drainage elements 144 to 162 are each disposed transverse to a longitudinal axis 56 c of the fin and are suitably disposed substantially perpendicular to the fin axis, as can be seen in FIG. 31 . It will be understood however that the drainage elements 144 to 162 may be oriented so that they are transverse to the fin axis 56 c but at non-perpendicular angles. The drainage elements 144 to 162 are each curved, having inner surfaces which have a curvature that substantially matches a curvature of the external surface 44 c of the drainage layer 22 c, an inner surface of drainage element 144 being shown in FIG. 33 and given the reference numeral 172.
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 FIG. 33 . The drainage elements 144 to 162 each taper in a direction from their base towards a respective tip, the tip 176 of drainage element 146 being shown in FIG. 33 . As can best be seen from FIG. 31 , a width of each drainage element W₁at its base (shown for the drainage element 146 in FIG. 31 ) reduces in a direction towards its tip, to a width W₂. An effective depth D₁of the drainage element 144 to 162 also reduces in a direction from its base 174 towards its tip 176, as again shown in FIG. 31 . The reduced depth at the tip 176 can be appreciated from the perspective view of FIG. 33 . Providing drainage elements 144 to 162 which taper in width and/or depth may help to promote the flow of liquid along the drainage elements and on to the fins 46 c for subsequent discharge, during use of the drainage promoter 14 c.
The drainage elements in the first row 164 are axially staggered along a length of the fin 46 c relative to the drainage elements in the second row 166. This can best be seen from FIG. 31 . Staggering the drainage elements in the first row 164 relative to the second row 166 can help to improve drainage of liquid from the drainage layer 22 c in the wet band 170. It will be understood however that the drainage elements in the first and second rows 164 and 166 may be axially aligned, for example by arranging the elements in pairs at common axial positions. For example, and viewing FIG. 31 , the drainage elements 144 and 146 may be arranged at a common axial position, and so aligned along a transverse axis of the fin 46 c.
Whilst the drainage elements 144 to 162 have been shown on a fin 46 c which is a sliding connection to its filter element 12 c in the fashion of the fin 46 b to the element 12 b, 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 FIG. 1 , and on the fin 46 a of FIG. 11 .
Turning now to FIG. 34 , there is shown a front view of a filter element assembly in accordance with another embodiment of the present disclosure, the filter element assembly indicated generally by reference numeral 10 d. The filter element assembly 10 d comprises a filter element 12 d and a drainage promoter 14 d. Like components of the filter element assembly 10 d with the filter element 10 shown in FIGS. 1 to 10 share the reference numerals, with the addition of the suffix “d”.
The filter element 10 d is of substantially the same construction as the filter element 12 shown in FIGS. 1 to 11 and described above. Accordingly, details of the construction and operation of the filter element 10 d will not be described again in detail, reference instead being made to the discussion of the filter element 12 forming part of the filter element assembly 10 described above. Any substantial differences between the filter element assembly 10 d and the assembly 10 will be described herein. In addition, the filter element assembly 10 d can be located in the housing 4 of a filter 2 in a horizontal orientation in the same way as the filter element assembly 10. Reference will therefore be made to the discussion above concerning the way in which the filter element assembly 10 d is located in a filter housing 4, and the way in which it operates during use.
The filter element assembly 10 d is also shown in the end views of FIGS. 35 and 36 , taken in the direction of the arrows A and B respectively in FIG. 34 . FIG. 37 is a perspective view and FIG. 38 a longitudinal cross-sectional view of the filter element assembly 10 d, both drawn to a smaller scale.
In this embodiment, the drainage promoter 14 d can be connected to a drainage layer 22 d of the filter element 12 d, rather than to first and second end caps 24 d and 26 d of the filter element 12 d, in the way that the previously described drainage promoters are connected to their respective filter elements. The drainage promoter 14 d is connected to the filter element 12 d at a location between first and second end caps 24 d and 26 d of the filter element. A fin 46 d of the drainage promoter 14 d comprises connection features which serve for connecting the fin directly to the drainage layer 22 d. 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 14 c discussed above.
The drainage promoter 14 d is shown separately in the front, end and perspective views of FIGS. 39, 40 and 41 . A first array 164 d of connection elements is provided, comprising connection elements 144 d, 148 d, 152 d, 156 d and 160 d. A second row or array 166 d comprises connection elements 146 d, 150 d, 154 d, 158 d and 162 d. The connection elements 144 d to 162 d are of similar construction to the drainage elements 146 to 162 described above, and can also provide a drainage function, serving to enhance the flow of liquid from the drainage layer 22 to the fin 46 d. However, a primary function of the connection elements 144 d to 162 d in this embodiment is to connect the fin 46 d to the drainage layer 22 d, and so to the filter element 12 d.
The connection elements 144 d to 162 d each have a shape which is substantially similar to the drainage elements 144 to 162, tapering from a base 174 d towards a tip 176 d, which is shown for the connection element 144 d in the end view of FIG. 40 . In this embodiment however, the drainage elements 144 d to 162 d are arranged to impart a clamping force on the drainage layer 22 d, for connecting the drainage promoter 14 d to the filter element 12 d. Specifically, the connection elements are arranged in pairs, axially adjacent connection elements (taken in a direction along a length of the fin 46 d) acting together to provide the clamping force. A clamping force is therefore exerted between the connection elements 144 d and 146 d, as well as between successive pairs of connection elements along the length of the fin 46 d. Thus, a clamping force is along exerted between the connection elements 146 d and 148 d, the connection elements 148 d and 150 d and so on. This is achieved by providing the connection elements as resilient arms, fingers or the like in a similar fashion to the drainage elements 144 to 162 described above.
In order to provide the clamping force, the connection elements 144 d to 162 d each extend from the fin 46 d around a circumference of the filter element 12 d to an over-centre position, relative to a central longitudinal axis 56 d of the filter element 12 d. A location of the central axis 56 d, and the over-centre positioning of the connection elements 144 d to 162 d, is shown in the end view of FIG. 40 . As can be seen, the pair of connection features 144 d and 146 d together encompass more than half of a circumference of the circular section drainage layer 22 d, and so the filter element 12 d. Effectively, the connection elements 144 d to 162 d together describe a generally cylindrical passage or opening 178 which is shaped to receive the filter element 12 d. A space is defined between the ends 176 of the connection elements 144 d to 162 d, the space indicated generally by reference numeral 180 in FIG. 20 . A dimension W₂of the space 180 is smaller than a diameter of the filter element 12 d at its drainage layer 22 d. This serves to provide the clamping force.
The drainage promoter 14 c described above is typically moulded as a unitary or one-piece component, comprising its fin 46 c and drainage features 144 to 162. The drainage promoter 14 d 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 22 d. This would require that the space 180 defined between the tips 176 of the connection features 144 d to 162 d be opened up to pass around the drainage layer 22 d, over its diameter to the over-centre position shown in FIG. 40 .
It may therefore be preferable to construct the drainage promoter 14 d as a two-piece structure, to facilitate fitting of the drainage promoter to the filter element 12 d. This is best shown in the end view of the drainage promoter 14 d in FIG. 42B, and the end view of the assembly in FIG. 42A, showing fitting of the drainage promoter to the filter element 14 d. Referring to FIG. 42B, first piece 182 of the drainage promoter 14 d comprises a first part 184 of its fin 46 d and the first row 164 d of connection features. A second piece 186 comprises a second part 188 of the fin 46 d and the second row 166 d of connection features. The first part 184 of the fin 46 d defines a first flank 165 d of the fin and a planar inner mating surface 190. The second part 188 of the fin 46 d comprises a second flank 167 d of the fin and a planar inner mating surface 192. The planar mating surface 190 is shown in the cross-sectional view of FIG. 38 and carries a number of mating protrusions 194 and mating apertures 196, the protrusions engaging in corresponding apertures (not shown) on the mating surface 192 and the apertures receiving corresponding mating protrusions 198 (one shown) on the mating surface 192. Engagement between the respective mating protrusions and apertures on the planar surfaces 190 and 192 serves for connecting the first and second pieces 182 and 186 of the fin together as shown in FIG. 40 . The first fin piece 182 is typically fitted to the drainage layer 22 d of the filter element 12 d as shown in FIG. 42A, and then the other fin piece 186 is connected to the first fin piece, so that the connection features 144 d to 162 d clamp the drainage layer 22 d.
When fitted to the filter element 12 d, the fin 46 d is disposed between the end caps 24 d and 26 d and spans a majority of the distance between the end caps.
Turning now to FIG. 43 , there is shown a front view of a filter element assembly in accordance with another embodiment of the present disclosure, the filter element assembly indicated generally by reference numeral 10 e. The filter element assembly 10 e comprises a filter element 12 e and a drainage promoter 14 e. Like components of the filter element assembly 10 e with the filter element assembly 10 shown in FIGS. 1 to 10 share the same reference numerals, with the addition of the suffix “e”.
The filter element 12 e is of substantially the same construction as the filter element 12 shown in FIGS. 1 to 11 and described above. Accordingly, details of the construction and operation of the filter element 10 e will not be described again in detail, reference instead being made to the discussion of the filter element 12 forming part of the filter element assembly 10 described above. Any substantial differences between the filter element assembly 10 e and the assembly 10 will be described herein. In addition, the filter element assembly 10 e can be located in a housing 4 of a filter 2 in a horizontal orientation in the same way as the filter element assembly 10. Reference will therefore be made to the discussion above concerning the way in which the filter element assembly 10 e is located in a filter housing 4, and the way in which it operates during use.
The filter element assembly 10 e is also shown in the end views of FIGS. 44 and 45 , taken in the direction of the arrows A and B respectively in FIG. 43 . In this embodiment, the drainage promoter 14 e can be connected to the filter element 12 e at a location between first and second end caps 24 e and 26 e of the filter element. The drainage promoter 14 e can be connected to a drainage layer 22 e, in a similar fashion to the drainage promoter 14 d discussed above.
The drainage promoter 14 e comprises a fin 46 e and first and second connection elements 200 and 202 which can engage the drainage layer 22 e, 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 46 e and are suitably provided at respective first and second axial ends 48 e and 50 e of the fin 46 e. It will be understood however that the connection components 200 and 202 may be provided at alternative locations on the fin 46 e, 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 46 e and around a circumference of the drainage layer 22 e. The drainage promoter 14 e is shown separately in the front, end and perspective views of FIGS. 46, 47 and 48 , which are drawn to a smaller scale, FIG. 47 viewing in the direction of the arrow D in FIG. 46 .
The first strap 200 comprises a first strap portion 204 which extends in a first direction away from the fin 46 e and around part of a perimeter of the drainage layer 22 e, 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 46 e to the filter element 12 e. 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 46 e to encompass the entire circumference of the drainage layer 22 e, 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 22 e, the strap being coupled at one end to the fin 46 e 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 46 e to secure it to the filter element 12 e, for example by passing through a locating aperture in the fin and around the drainage layer (or in an alternative, around an end cap).
FIGS. 49 and 50 are front and end views of the filter element assembly 10 e shown during fitting of the drainage promoter 14 e to the filter element 12 b, drawn to a smaller scale. As shown in these drawings, the drainage promoter is introduced to the filter element 12 e so that the fin 46 e is positioned adjacent to the drainage layer 22 e and located between the end caps 24 e and 26 e. The first strap portions 204 and 208 pass away from the fin 46 e on one side of the fin, and the second strap portions 206 and 210 pass away from the other side of the fin. The strap portions 204 and 206 can then be brought together to encircle the drainage layer 22 e, by bringing ends of the strap portions together in the direction of the arrows E and F shown in FIG. 50 . The stepped end portion 209 on the first strap portion 204 can be located so that it passes over the button 207 on the second strap portion 206, and the button press-fitted through the aperture 205 to connect the two strap portions together. A similar procedure can then be followed for the strap portions 208 and 210 of the second strap 202.
Engagement of the strap portions 204, 206 and 208, 210 exerts a clamping force on the drainage layer 22 e, causing the fin 46 e to press into its external surface 44 e, as shown in the longitudinal cross-sectional view of FIG. 51 . The fitted drainage promoter 14 e therefore adopts the position shown in the perspective view of FIG. 52 . The connection straps 200 and 202 can also act to compress the drainage layer 22 e, to provide improved drainage, in a similar fashion to the drainage elements discussed above.
When fitted to the filter element 12 e, the fin 46 e is disposed between the end caps 24 e and 26 e 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 14 e and 14 d) 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 FIG. 11 , the fin 46 a may be pivotally connected to the second end cap 26 a and may latch-fit to the first end cap 24 a.
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.

Claims

1. A filter element assembly, comprising:

a filter element for location in a housing of a filter, the 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, 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; and

a drainage promoter comprising a fin configured to be connected to the filter element so that, in use, it extends along the filter element substantially an entire distance between the first and second end caps and compresses the drainage layer along its length to promote drainage of liquid which has collected in the drainage layer, and wherein the fin comprises at least one connection feature for engaging the filter element, to connect the fin to the filter element.

2. The filter element assembly as claimed in claim 1, in which the fin is elongate, having first and second axial ends, a base extending along a length of the fin between the ends, and a tip opposite the base and extending along the length of the fin, in which the tip defines a free edge of the fin and the base presses into the drainage layer during use.

3. The filter element assembly as claimed in claim 2, in which the tip defines a discharge location from which liquid flowing from the drainage layer can be discharged from the fin, and in which the fin has a tapered shape in cross-section, tapering in a direction towards its tip.

4. The filter element assembly as claimed in claim 1, in which the fin is configured to be connected to at least one of the first and second end caps, so that it can be secured to the filter element.

5. The filter element assembly as claimed in claim 4, in which the fin is configured to be connected to both end caps so that it extends from one end cap to the other end cap.

6. The filter element assembly as claimed in claim 1, in which the fin is configured to be releasably connected to at least one of the end caps.

7. The filter element assembly as claimed in claim 1, in which the connection feature engages an end cap of the filter element.

8. The filter element assembly as claimed in claim 7, in which the fin comprises 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 being spaced apart along a length of the fin.

9. The filter element assembly as claimed in claim 8, in which the fin comprises a first axial end and a second axial end, and the first and second connection features are provided at or near the respective first and second axial ends.

10. The filter element assembly as claimed in claim 7, in which the filter element comprises at least one connection feature, which cooperates with the connection feature on the fin for connecting the fin to the element.

11. The filter element assembly as claimed in claim 10, in which at least one of the end caps comprises the connection feature.

12. The filter element assembly as claimed in claim 11, in which the first end cap comprises a first connection feature and the second end cap comprises a second connection feature, the first and second end cap connection features being configured to cooperate with respective first and second connection features of the fin, to connect the fin to the filter element.

13. The filter element assembly as claimed in claim 10, in which:

the connection feature of the fin is a male connection feature, and the connection feature of the filter element is a corresponding female connection feature; or

the connection feature of the fin is a female connection feature, and the connection feature of the filter element is a corresponding male connection feature.

14. The filter element assembly as claimed claim 1, comprising a pivoting connection between the fin and the filter element.

15. The filter element assembly as claimed in claim 14, in which one of the fin and the filter element defines a connection feature in the form of a pivot pin, and the other one of the fin and the filter element defines a pivot mount shaped to receive the pivot pin, so that the fin can pivot relative to the filter element.

16. The filter element assembly as claimed in claim 15, in which the pivot pin and the pivot mount are aligned along a longitudinal axis of the fin, so that the fin can pivot about its longitudinal axis between a folded position and a deployed position.

17. The filter element assembly as claimed in claim 15, in which the fin comprises 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.

18. The filter element assembly as claimed in claim 15, in which the pivot pin and the pivot mount are disposed on a pivot axis which is transverse to the longitudinal axis of the fin when the fin is connected to the filter element.

19. The filter element assembly as claimed in claim 18, in which the fin comprises a first pivot pin portion extending in a first lateral direction away from the fin, and a second pivot pin portion extending in a second lateral direction away from the fin.

20. The filter element assembly as claimed in claim 18, in which the fin is pivotable about the pivot axis between a disconnected position in which the fin is not connected the filter element, and a connected position in which the fin is connected to the filter element, and in which, in the connected position, the longitudinal axis of the fin is disposed substantially parallel to a longitudinal axis of the filter element.

21. The filter element assembly as claimed in claim 18, in which the fin and the filter element define respective latch features, which cooperate to provide a latching engagement between the fin and the element.

22. The filter element assembly as claimed in claim 21, in which the latch feature on the fin is spaced along a length of the fin from its pivot pin or pivot mount, and the latch feature on the filter element is provided on one of the end caps.

23. The filter element assembly as claimed in claim 21, in which one of the latch features provided by the fin and the filter element is a resiliently deformable latch arm.

24. The filter element assembly as claimed in claim 10, comprising a sliding connection between the fin and the filter element, the sliding connection defined by connection features of the fin and the filter element.

25. The filter element assembly as claimed in claim 24, in which the fin is 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.

26. The filter element assembly as claimed in claim 24, in which one of the fin and the filter element defines a connection feature in the form of a key, and the other one of the fin and the filter element defines a keyway shaped to receive the key in a sliding fit.

27. The filter element assembly as claimed in claim 24, in which the first end cap comprises a first connection feature for engaging a corresponding first connection feature on the fin, the second end cap comprises a second connection feature for engaging a corresponding second connection feature on the fin, and in which 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, require to be aligned in order for the fin to be connected to the element.

28. The filter element assembly as claimed in claim 24, in which at least one of the end caps comprises a plurality of connection features which are spaced around a perimeter of the end cap.

29. The filter element assembly as claimed in claim 1, in which the fin is configured so that it is connected to the filter element in a press-fit between the end caps.

30. The filter element assembly as claimed in claim 1, in which the drainage promoter comprises at least one drainage element which is coupled to the fin and extends in a direction away from the fin and around an outer surface of the drainage layer.

31. The filter element assembly as claimed in claim 30, in which the drainage element extends part way around a perimeter of the outer surface and is disposed transverse to a longitudinal axis of the fin.

32. The filter element assembly as claimed in claim 1, in which the at least one drainage element has a base at which it is coupled to the fin and extends away from the base to a tip which defines a free end, the at least one drainage element tapering in a direction from the base towards the tip.

33. The filter element assembly as claimed in claim 30, in which, in use, at least one first drainage element extends from the fin around the outer surface of the drainage layer in a first direction around the perimeter of the filter element, and at least one second drainage element extends from the fin around the outer surface of the drainage layer in a second direction around the perimeter of the filter element.

34. The filter element assembly as claimed in claim 33, in which the first and second drainage elements extend from respective first and second flanks of the fin.

35. The filter element assembly as claimed in claim 33, in which, in use, the first and second drainage elements are configured to together impart a clamping force on the filter element, for connecting the drainage promoter to the element.

36. The filter element assembly as claimed in claim 33, in which, in use, the drainage elements each extend around the perimeter of the filter element to an over-centre position, relative to a central axis of the filter element, so that the first and second drainage elements together encompass more than half of a circumference of the filter element.

37. The filter element assembly as claimed in claim 33, in which the first and second drainage elements together describe a generally cylindrical passage between their inner surfaces, which passage is shaped to receive the filter element.

38. The filter element assembly as claimed in claim 37, in which the passage has a central axis, and the drainage elements each extend, in use, to an over-centre position relative to the central axis.

39. The filter element assembly as claimed in claim 33, in which a space is defined between a free end of the first drainage element and a free end of the axially adjacent second drainage element, and in which a dimension of the space, measured in a direction perpendicular to a longitudinal axis of the filter element, is smaller than a width of the filter element.

40. The filter element assembly as claimed in claim 30, in which the drainage promoter comprises a first part defining a first part of the fin and at least one drainage element, and a second part defining a second part of the fin and at least one drainage element, and in which the first and second fin parts are adapted to be coupled together to form the drainage promoter.

41. The filter element assembly as claimed in claim 1, in which the drainage promoter is configured to be connected to the filter element at a location between the first and second end caps.

42. The filter element assembly as claimed in claim 41, in which the drainage promoter comprises at least one connecting component which is configured to engage the drainage layer, to connect the fin to the filter element.

43. The filter element assembly as claimed in claim 42, in which the connecting component is a strap which extends, in use, from the fin and around at least part of a perimeter of the drainage layer.

44. The filter element assembly as claimed in claim 43, in which the strap comprises a first strap portion extending, in use, in a first direction away from the fin and around part of a perimeter of the drainage layer, and a second strap portion extending in a second direction away from the fin and around part of a perimeter of the drainage layer, and in which the first and second strap portions are adapted to be coupled together to connect the fin to the filter element.

45. A drainage promoter which can be connected to a filter element, the drainage promoter comprising:

at least one fin which can be fitted to the filter element so that it extends along the filter element substantially an entire distance between first and second end caps of the filter element, to compress a drainage layer of the filter element along its length and promote drainage of liquid which has collected in the drainage layer;

in which the fin comprises a first connection feature configured to engage the first end cap of the filter element, and a second connection feature configured to engage the second end cap of the filter element, for connecting the fin to the filter element.

46. A drainage promoter which can be connected to a filter element, the drainage promoter comprising:

at least one fin which can be fitted to the filter element so that it extends along the filter element substantially an entire distance between the first and second end caps, to compress a drainage layer of the filter element along its length and promote drainage of liquid which has collected in the drainage layer; and

at least one connecting component configured to engage the drainage layer to connect the fin to the filter element.

47. A drainage promoter which can be connected to a filter element, the drainage promoter comprising:

at least one fin which can be fitted to the filter element so that it extends along the filter element substantially an entire distance between the first and second end caps, to compress a drainage layer of the filter element along its length and promote drainage of liquid which has collected in the drainage layer, the fin having first and second axial ends and a longitudinal axis extending along the fin between its axial ends; and

at least one drainage element coupled to the fin and extending in a direction away from the fin, transverse to its longitudinal axis.

48. 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 claim 47 to the drainage layer of the filter element.

49. A filter element for location in a housing of a filter, the filter element comprising:

a wall of a filtration medium which defines a hollow space, for a fluid 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 fluid separated from the fluid stream can collect;

first and second end caps at opposite ends of the wall, one of the end caps including a port for a fluid stream which communicates with the space within the wall; and

at least one connection feature configured to cooperate with a connection feature on a drainage promotor fin, for connecting the filter element to the drainage promotor fin.

50. A filter element assembly, comprising:

a filter element for location in a housing of a filter, the 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, the filtration medium including a filtration layer, and a drainage layer located in surrounding relation to 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 hollow space within the wall; and

a drainage promoter comprising a fin connected to the filter element so that, the drainage promoter extending along the filter element substantially an entire distance between the first and second end caps and compressing the drainage layer along its length to promote drainage of liquid which has collected in the drainage layer during use, and wherein the fin comprises at least one connection feature for engaging the filter element, to connect the fin to the filter element.

51. The filter element assembly as claimed in claim 50, in which the first end cap comprises a first connection feature and the second end cap comprises a second connection feature, the first and second end cap connection features being configured to cooperate with respective first and second connection features of the fin, to connect the fin to the filter element.

52. The filter element assembly as in claim 50, in which the first and second connection features of the first and second end caps are configured to releasably connect the fin to the filter element.