Note: Descriptions are shown in the official language in which they were submitted.
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FLUID TREATMENT ASSEMBLY
Background of the Invention
1. Field of the Invention
This invention relates to a fluid treatment assembly
including a plurality of fluid treatment elements which are
arranged in a nested relationship and which are detachable from
each other to enable the elements to be individually replaced.
In particular, it relates to a fluid treatment assembly including
a filter element and a coalescer element.
2. Description of the Related Art
Fluid treatment assemblies comprising a plurality of fluid
treatment elements in a nested relationship are used to make
efficient use of the space within the outermost of the elements.
One example of such an assembly is one containing a filter
element for removing solid particles from a fluid and a coalescer
element for coalescing one component of the fluid, either before
or after the fluid has passed through the filter element.
The two fluid treatment elements in a fluid treatment
assembly may have a different lifespan from each other, so it may
be advantageous if the two fluid treatment elements are readily
detachable from each other to enable them to be individually
replaced.
Summary of the Invention
The present invention provides a fluid treatment assembly
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including a plurality of fluid treatment elements which are
disposed in a nested relationship and which are detachable from
each other so as to permit their individual replacement.
The present invention further provides a fluid treatment
element capable of being detachably arranged with respect to
another fluid treatment element in a nested relationship.
The present invention additionally provides a method of
using~a fluid treatment assembly including a plurality of fluid
treatment elements arranged in a nested relationship.
According to one aspect of the present invention, a fluid
treatment element is in the form of a coalesces element for use
in a nested relationship with a filter element. The coalesces
element includes a coalesces body including a coalescing medium,
a first open end cap sealed to a first lengthwise end of the
coalesces body, and a second open end cap sealed to a second
lengthwise end of the coalesces body. The first end cap includes
an annular base with an opening sized to enable a filter element
to pass through it and a hollow neck extending from the base.
The neck has a surface on an interior thereof against which a
first end cap of a filter element can be sealed. The second end
cap includes an annular base and a hollow neck extending from the
base into the coalesces body and having a surface on an exterior
thereof against which a second end cap of a filter element can be
sealed.
According to another aspect of the present invention, a
fluid treatment element is in the form of a filter element for
use in a nested relationship with a coalesces element. The
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filter element includes a filter body containing a filter medium
for removing solids from a fluid and sized to enable its
insertion into a bore of a coalesces element, and a blind end cap
sealed to a first lengthwise. end of the filter body and adapted
for sealing on an exterior thereof against the coalesces element.
The blind end cap may have a surface adapted for engagement with
a retaining member which can be detachably connected to the
coalesces element to restrict lengthwise movement of the filter
element. The filter element may also include an open end cap
adapted for sealing against a surface of the coalesces element.
The end caps of the filter element are preferably spaced from
each other by a distance such that they can simultaneously be
sealed to the coalesces element.
According to yet another aspect of the present invention, a
fluid treatment assembly includes first and second fluid
treatment elements, such as a coalesces element and a filter
element. The first fluid treatment element includes a body
containing a fluid treatment medium and having an open end. The
second fluid treatment element is disposed inside the first fluid
treatment element and includes a body containing a fluid
treatment medium and a blind end cap detachably sealed to the
first fluid treatment element. The assembly may further include
a retainer detachably connected to one of the elements and
restricting lengthwise movement of the elements with respect to
each other to prevent the elements from becoming unsealed from
each other.
According to a still further aspect of the present
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invention, a method of using a coalesces element includes passing
a process fluid in succession through a filter element detachably
sealed to and disposed in a nested relationship with the
coalesces element while restricting relative lengthwise movement
between the two elements with a retainer to a level such that the
two elements remain sealed to each other. The retainer is then
disconnected from the coalesces element and the filter_element is
removed from the coalesces element. Another filter element may
then be disposed in a nested relationship with the coalesces
element.
According to another aspect of the present invention, a
method of using a fluid treatment assembly includes inserting a
filter element having a first lengthwise end equipped with a
blind end cap and an open second lengthwise end into a coalesces
element and detachably sealing the blind end cap against the
coalesces element. A process fluid is than passed in succession
through the filter element and the coalesces element.
The fluid treatment elements of a~fluid treatment assembly
according to the present invention are not restricted to any
specific type, and the different elements may perform the same or
different types of treatment. Some examples of types of
treatment which can be performed are filtration, coalescing, and
separation of a coalesced fluid from another fluid. In preferred
embodiments, the fluid treatment elements include a filter
element for removing solid particles from a fluid and a coalesces
element for coalescing a component of the fluid passing through
the filter element. A process fluid to be treated by the fluid
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treatment elements need not be of a particular type. For
example, it may be primarily a liquid, primarily a gas, or a
multiphase mixture.
In preferred embodiments, a fluid treatment assembly
includes only two fluid treatment elements in a nested
relationship, but a larger number of fluid treatment elements may
be nested to provide more levels or more types of fluisi
treatment.
Although the present invention will be described with
respect to a number of preferred embodiments, the present
invention is not limited to the specific structures of those
embodiments, and one or more features of one embodiment may be
freely combined with one of more features of another embodiment
without departing from the scope of the present invention.
Brief Description of the Drawings
Figure 1 is a cross-sectional elevation of an embodiment of
a fluid treatment assembly according to the present invention.
Figure 2 is an enlarged vertical cross-sectional view
showing the structure of the upper portion of the body of the
coalescer element of Figure 1.
Figure 3 is a plan view of the retaining nut of the
embodiment of Figure 1.
Figure 4 is a cross-sectional elevation of a modification of
the embodiment of Figure 1 employing a different type of
retaining member.
Figure 5 is an isometric view of the retainer of the
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embodiment of Figure 4.
Description of Preferred Embodiments
Figures 1-3 illustrate a first embodiment of a fluid
treatment assembly according to the present invention. As best
shown in Figure 1, which is a cross-sectional elevation, this
embodiment includes a first fluid treatment element comprising a
filter element 10 for removing solid particles from a fluid and a
second fluid treatment element comprising a coalesces element 40
for coalescing a component of a fluid which passes through the
filter element 10. The two fluid treatment elements 10, 40 are
disposed in a nested relationship with respect to each other,
with the two elements being readily detachable from each other to
enable them to be individually replaced.
In the drawings, the fluid treatment elements 10, 40 are
illustrated as being vertically oriented, but they can have any
orientation with respect to the vertical. For convenience, the
terms "upper" and "lower" may be used to refer to various
portions of the fluid treatment elements, but use of these terms
is not intended to impose any restrictions on the manner in which
the elements can be oriented.
A process fluid being treated is intended to flow
substantially radially through the filter element 10 and the
coalesces element 40 between the hollow interior of the assembly
and the region surrounding the assembly. While the illustrated
assembly is intended primarily for radially outward flow of
process fluid during normal operation, a fluid treatment assembly
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according to the present invention may also be used for radially
inward flow. In fluid treatment assemblies employing a filter
element and a coalesces element in series, it is typical for the
filter element to be on the upstream side of the coalesces
element so as to act as a prefilter for the coalesces element and
remove solid particles which could clog the coalesces element and
impair its performance, but it is also possible for process fluid
to flow through the two elements in the reverse order. Since the
illustrated assembly is intended for radially outward flow of
process fluid with the process fluid passing through the filter
element 10 before passing through the coalesces element 40, the
filter element 10 is shown installed on the interior of the
coalesces element 40, but if the assembly is intended for
radially inward flow of process fluid, the filter element 10 may
be installed on the exterior of the coalesces element 40.
The filter element 10 includes a filter body 20 capable of
being inserted into the hollow interior of the coalesces element
40 and containing one or more filter medium capable of removing
solid particles from a fluid passing through it. The filter body
20 may have any structure appropriate for the type of particles
which it is desired to remove from the fluid being processed. To
give but a few examples, the filter body 20 may be a pleated
structure, a spirally wound structure, a string wound structure,
a tubular fibrous mass, a plurality of concentric cylindrically
wound layers, or a bag. A pleated filter body having a
configuration like that described in U.S. Patent No. 5,543,047 or
WO 96/33789, for example (the disclosures of which are
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incorporated by reference), in which a plurality of pleats are
formed into a cylindrical body with the heights of the pleats
being greater than (D-d) /2 and less than (Dz -d2) / [4 (d+2t) ) ,
wherein D is the outer diameter of the cylindrical body, d is the
S inner diameter of the cylindrical body, and t is the thickness of
each pleat, is frequently suitable because such a filter body has
a large surface area available for filtration for a given volume
of the filter body as well as high strength. Furthermore, such a
configuration can increase the dirt capacity of the filter body
by providing more uniform flow conditions. In Figure 1, the
filter body 20 is a hollow member with a cylindrical inner and
outer periphery, but it may have other peripheral shapes, such as
oval or polygonal, and its shape may vary over its length.
Furthermore, it need not be hollow. The filter medium in the
filter body 20 may be any type suitable for the type and size of
the particles which are to be removed from the fluid being
processed. A few examples of types of filter media which may be
employed are fibrous mats, woven or non-woven fibrous sheets,
porous membranes such as supported or unsupported microporous
membranes, porous foams, and porous metals or ceramics. The
filter medium may be formed from any suitable materials,
including but not being limited to natural or synthetic polymers,
glass, metals, and ceramics. In addition to a filter medium,. the
filter body 20 may contain a variety of other conventional
components, such as one or more drainage layers to provide
support and/or drainage for the filter medium, and one or more
cushioning layers to protect the filter medium from abrasion.
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Depending upon the strength required of the filter element
10, it may be equipped with various reinforcing or protecting
members, such as a perforated core or other internal support, a
perforated cage or other external support, or an external wrap
member to restrain the filter body 20 against outward forces and
to help the filter body 20 maintain a desired shape.
If desired, one or both lengthwise ends of the filter
element 10 may be equipped with an end cap to perform one or more
functions, such as sealing a lengthwise end of the filter body
20, protecting the lengthwise ends against damage, providing a
sealing surface against which a seal can be formed between the
filter element 10 and another member, or to provide a structure
by which the filter element 10 can be secured to another member.
In the present embodiment, fluid is intended to be introduced
into the fluid treatment assembly through its lower end and then
flow radially outwards through the two fluid treatment elements
10 and 40, so the upper lengthwise end of the filter element 10
is equipped with a blind upper end cap 30 which closes off the
upper lengthwise end, and the lower lengthwise end of the filter
element 10 is equipped with an open lower end cap 35 through
which fluid can flow into the center of the filter element 10.
Alternatively, both end caps 30, 35 may be open end caps. The
upper end cap 30 may be equipped with a handle 31 or other
structure by which the filter element 10 can be grasped when it
is to be withdrawn from or inserted into the coalescer element
40. The upper end cap 30 may also include structure by which it
can be secured to the interior of a housing in which it is
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installed during operation. For example, the illustrated upper
end cap 30 includes a threaded bore 32 for receiving a stud for
detachably connecting the filter element 10 to a retaining spider
of a filter housing to prevent the filter element 10 from
wobbling during operation.
Each end cap 30, 35 can be sealed to a lengthwise end of the
filter body 20 in any manner suitable for the materials of which
the filter body 20 and the end caps are made, such as by adhesive
bonding, melt bonding, spin welding, or by use of a gasket or
other sealing member disposed between the end cap and the filter
body 20.
The coalesces element 40 includes a hollow coalesces body 50
containing a porous coalescing medium capable of coalescing one
or more components in a fluid passing through it. The coalesces
body 50 may have any structure suitable for the type of
coalescing which it is desired to perform. Examples of types of
coalescing which the coalesces element 40 may be used to perform
include removal of a liquid phase from a gaseous phase, and
removal of a first liquid phase from a second liquid phase. A
few examples of many possible structures which can be employed
for the coalesces body 50 are those described in U.S. Patent No.
4,759,782 entitled "Coalescing Filter for Removal of Liquid
Aerosols from Gaseous Streams", U.S. Patent No. 5,443,724
entitled "Apparatus for Separating the Components of a
Liquid/Liquid Mixture", U.S. Patent No. 5,480,547 entitled
"Corrosive Liquid Coalesces", and International Publications Nos.
WO 96/33789 entitled "Method and Apparatus for Separating and
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Immiscible Liquid/Liquid Mixture Containing Solid Matter", WO
97/38781 entitled "Disposable Coalesces", and WO 98/14257
entitled "Coalesces Element", the disclosures of which are
incorporated by reference. As shown in Figure 2, which is an
enlarged vertical cross-sectional view of a portion of the
coalesces body 50 of Figure 1, in the present embodiment, the
coalesces body 50 has a multi-layer structure including a
cylindrical depth filter medium 51 comprising continuous
polymeric fibers and sold by Pall Corporation under the trade
name PROFILE, a porous cylindrical sleeve 52 surrounding the
depth filter medium 51 and made of a lightly needled polyester
felt with a weight of approximately 9 ounces per square yard and
an uncompressed thickness of approximately 3/16 inch, a porous
cylindrical sleeve 53 made of a high loft polyester batting with
a weight of approximately 6.5 ounces per square yard and an
uncompressed thickness of approximately 5/8 inch, two porous
cylindrical sleeves 54 surrounding sleeve 53 and each made of a
lightly needled polyester felt with a weight of approximately 5
ounces per square yard and an uncompressed thickness of
approximately 0.1 inches, and a perforated sleeve 55 of a porous
non-woven polyester sheet available from Reemay of Old Hickory,
Tennessee under the trade name REEMAY with a weight of
approximately 1 ounce per square yard and an uncompressed
thickness of approximately 0.008 inches
which has been treated by any convenient conventional method to
render it hydrophobic. Such a multilayer structure can be used
for a variety of applications but is particularly suitable for
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coalescing water from a liquid hydrocarbon, such as jet fuel or
other fuel. Porous layers 51 - 54, which become less dense and
coarser from layer 51 to layer 54, are able to coalesce water
present in fuel into larger and larger droplets as the fuel flows
radially outwards through the layers. The perforated sleeve 55
is pervious to hydrocarbon fuel but is impervious to water except
in the perforations due to its having been hydrophobically
treated, so it can increase the efficiency of coalescing by
increasing the size of the water droplets which are coalesced in
layers 51 - 54 and reduce re-entrainment of the droplets in the
fuel leaving the coalescer body 50,,as described, for example, in
WO 98/14257. The use of polyester fibers for the various porous
layers 51 - 55 is frequently suitable when the fluid being
treated is a petroleum-based fuel because of the compatibility of
polyester with such fuels, but any other fibers compatible with
the fluid being treated may also be employed.
If desired, the coalescer element 40 may include an internal
or external reinforcing member, such as a perforated core 56
and/or an unillustrated perforated cage, to reinforce the
coalescer body 50. In the present embodiment, the inner
periphery of the core 56 is preferably sufficiently close to the
outer periphery of the filter body 20 so as to be able to act as
an external reinforcing member for the filter body 20 and
reinforce it against radially outward fluid forces. To
facilitate assembly, it may be convenient if there is a radial
clearance between the outer periphery of the filter element 10
along the filter body 20 and the inner periphery of the core 56
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when no differential pressure is acting on the assembly, with the
radial clearance being sufficiently small that the amount of
radial expansion of the filter body 20 until it is restrained by
the core 56 is below a level that can damage the filter body 20.
The appropriate amount of clearance will depend upon the strength
of the filter body 20. In the present embodiment, the radial
clearance between the outer periphery of the filter element 10
along the filter body 20 and the inner periphery of the core 56
is preferably approximately 0.030 - 0.090 inches, and more
preferably approximately 0.060 inches.
The coalescer element 40 will frequently have a peripheral
shape similar to that of the filter element 10, but the two
elements may differ from each other in shape. The illustrated
coalescer element 40 has a cylindrical inner and outer periphery,
but it may have other peripheral shapes, such as oval or
polygonal, and its shape may vary over its length.
The coalescer element 40 may be equipped with an end cap at
one or both of its lengthwise ends to perform one or more
functions like those which may be performed by the end caps of
the filter element 10. In the present embodiment, the coalescer
element 40 is equipped with an open end cap 60, 70 at each of its
lengthwise ends. The upper end cap 60 includes an annular base
61 which is secured to the core 56 and/or the coalescer body 50
and is sealed to the upper lengthwise end of the coalescer body
50. A cylindrical neck 62 extends upwards from the base 61 and
surrounds the upper end cap 30 of the filter element 10. The
inner diameter of the upper end cap 60 is large enough so that
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the filter element 10 can pass through the upper end cap 60 when
being inserted into or removed from the coalescer element 40.
The lower end cap 70 includes an annular base 71 having an
upper surface sealed to the lower end face of the coalescer body
50 and secured to one or both of the coalescer body 50 and the
core 56, and a hollow first neck 72 which extends upwards from
the base 71 into the first filter element l0. It may also
include a second neck 73 which extends downwards from the base 71
and which can be used to connect the end cap 70 to other
equipment, such as a tube sheet, a nipple, or another fluid
treatment assembly. The illustrated second neck 73 is equipped
with internal threads 74 which can be screwed onto a threaded
portion of another member, such as a threaded nipple of a filter
housing. The lower end cap 70 may also be equipped with an
unillustrated sealing member, such as a gasket, to form a seal
between the fluid treatment element and a member to which the
element is connected by the lower end cap 70. The illustrated
end cap 70 is formed as a single piece, but it may instead be
formed from a plurality of sections which are joined to each
other by bonding, welding, spin welding, or other suitable
method, depending upon the materials of which it is made.
The end caps 60, 70 of the coalescer element 40 may be
sealed to the lengthwise ends of the coalescer body 50 by any
suitable methods, such as those described with respect to the end
caps for the filter element 10.
The end caps of both elements 10 and 40 and the core 56 of
the coalescer element 40 are illustrated as being made of a
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polymeric material, but there are no restrictions on the
materials of which these portions and other hardware of the
elements are formed. Thus, polymers, metals, ceramics, or any
other materials compatible with other portions of the elements
and the fluid being processed may be employed.
The filter element 10 and the coalescer element 40 are
preferably detachably sealed to each other so as to prevent fluid
which is to be treated from bypassing one or both elements by
flowing along any gap between the two while permitting the
elements to be readily detached from each other without damage to
the elements. Seals may be formed in any desired locations of
the elements, the seals may be of any desired types (such as
piston seals or axial face seals), and the seals may be formed
with or without the use of sealing members such as gaskets or
sealing rings. In the present embodiment, a piston seal is
formed between each end cap of the filter element 10 and one of
the end caps of the coalescer element 40 by a suitable sealing
mechanism. The sealing mechanism may be integrally formed with
the end caps, or it may be separately formed from the end caps
and then mounted thereon. For example, the sealing mechanism may
comprise a region of an end cap formed of an elastomer or other
resilient material capable of directly sealing against another
member such as against another end cap, or it may comprise a
ring, a gasket, or other sealing member mounted on an end cap.
As shown in Figure 1, the upper end cap 30 of the filter element
10 is sealed to the upper end cap 60 of the coalescer element 40
by a sealing mechanism comprising an O-ring 33 which is mounted
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in a groove on the exterior of the upper end cap 30 and forms a
piston seal against the interior surface of the neck 61 of the
upper end cap 60 of the coalesces element 60. Similarly, the
lower end cap 35 of the filter element 10 is sealed to the lower
end cap 70 of the coalesces element 40 by a sealing mechanism
comprising an O-ring 36 mounted in a groove formed in the
interior of the lower end cap 35 to form a piston seal_ against
the exterior of the first neck 72 of the lower end cap 70 of the
coalesces element 40. Alternatively, the lower end cap 35 of the
filter element 10 may have a neck or other portion which can be
inserted into the first neck 72 of end cap 70, and a piston seal
may be formed between the exterior of the neck of the lower end
cap 35 and the interior of the first neck 72 of end cap 70 by an
O-ring or other sealing member mounted on one of the two necks.
Additional sealing members may be mounted on the end caps of one
or both elements 10, 40. It may be convenient for any sealing
members which may require replacement to be installed on the
filter element 10 rather than on the coalesces element 40, since
they can be more readily accessed and replaced than if mounted on
the coalesces element 40. The distance between the two end caps
30, 35 of the filter element 10 is such that they can be
simultaneously sealed to the end caps of the coalesces element
40.
Instead of the lower end cap 35 of the filter element 10
being sealed to the coalesces element 40, it is possible for it
to be sealed to another member, such as to a hollow fitting of a
tube sheet or other member on which the coalesces element 40 is
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mounted. Thus, the lower ends of the filter element 10 and the
coalesces element 40 may be sealed to the same member without
being directly sealed to each other.
During operation of the assembly, the difference between the
fluid pressure on the interior and the exterior of the assembly
may tend to urge the filter element 10 upwards in Figure 1 in the
lengthwise direction with respect to the coalesces element 40.
If the filter element 10 is moved too far in its lengthwise
direction by fluid pressure, it may become unsealed from the
coalesces element 40. The assembly may therefore be equipped
with structure which can prevent the relative lengthwise movement
of the two fluid treatment elements 10, 40 or to limit any
lengthwise movement to an amount such that the two fluid
treatment elements 10, 40 remain sealed to each other. A wide
variety of structures can be employed for this purpose, such as
threaded engagement between the two fluid treatment elements, a
snap fit or bayonet fit between the adjoining upper or lower end
caps of the two fluid treatment elements, or a retaining member
such as a nut, a retaining pin, a clamp, or a latch formed
separately from the fluid treatment elements and detachably
connectable to one or both elements. In the present embodiment,
relative lengthwise movement of the two fluid treatment elements
is restricted by a retaining member comprising a retaining nut
80, shown in plan in Figure 3, which can be detachably mounted on
the upper end cap 60 of the coalesces element 40 atop the upper
end cap 30 of the filter element 10. The nut 80 includes an
outer cylindrical wall 81 having internal threads with engage
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with external threads 63 formed on the neck 62 of the upper end
cap 60, and a plate 82 which extends radially inwards from the
wall 81 and overlaps the upper end cap 30 of the filter element
in a radial direction so as to block the upwards movement of
5 the filter element 10 with respect to the coalescer element 40.
The plate 82 may have an opening 83 through which the handle 31
or other portion of the upper end cap 30 of the filter element 10
can pass. However, if there are no upwardly projecting members
formed on the upper end cap, the plate 82 may be without an
10 opening. The plate 82 may contact the upper end cap 30 of the
filter element 10 to completely restrain the filter element 10
against lengthwise movement, or the plate 82 may be spaced from
the upper end cap 30 to permit a certain amount of movement of
the filter element 10 in its lengthwise direction, with the
amount of movement being sufficiently small that the end caps of
the two elements are not unsealed from each other. However,
since fluid pressure exerts an upwards force on the filter
element 10 during operation of the assembly, the upper end cap 30
of the filter element 10 will usually be pressed into contact
with the plate 82 once operation of the assembly starts, even if
the plate 82 and the end cap 30 do not initially contact each
other when the nut 80 is mounted on the upper end cap 60 of the
coalescer element 40. The illustrated nut 80 is not attached to
the upper end cap 30 of the filter element 10, but it may instead
be attached to the upper end cap 30 by a retaining ring, for
example, to permit the nut 80 to rotate with respect to the upper
end cap 30 while preventing it from becoming completely detached,
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thereby enabling the filter element 10 and the retaining nut 80
to be handled as a single unit.
To install the fluid treatment assembly in a fluid treatment
system, the coalesces element 40 can be inserted into a housing,
for example, of the fluid treatment system, and the lower end cap
70 can be screwed onto a hollow threaded male fitting of the
housing. One or both of the end caps 60, 70 of the coalesces
element 40 may be equipped with recesses, projections, or flat
surfaces suitable for being grasped by a wrench or other tool to
facilitate the rotation of the coalesces element 40 when the
lower end cap 70 is being screwed onto the fitting. After the
coalesces element 40 is installed in the housing, the filter
element 10 can be inserted into the coalesces element 40 until
the O-ring 36 on the lower end cap 35 of the filter element 10
seals against the exterior of the first neck 72 of the lower end
cap 70 of the coalesces element 40 and the O-ring 33 on the upper
end cap 30 of the filter element 10 seals against the interior
surface of the neck 62 of the upper end cap 60 of the coalesces
element 40. The retaining nut 80 can then be screwed onto the
external thread 63 of the upper end cap 60 of the coalesces
element 40 to prevent or limit the axial movement of the filter
element 10 so as to prevent it from being unsealed from the
coalesces element 40. The fluid treatment assembly is now ready
to be used for fluid treatment. During operation, a process
fluid to be treated is introduced into the assembly through the
lower end caps 35, 70 of the elements l0, 40 and flows into the
interior of the filter element 10. The process fluid flows
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radially outwards through the filter body 20 of the filter
element 10, which removes solid particles of a predetermined size
from the process fluid. The filtered process fluid then flows
radially outwards through the coalesces element 40, in the
process of which one or more component of the process fluid is
coalesced. The coalesced and non-coalesced components can then
be removed from the housing along different flow paths for
collection, discarding, or further processing, for example.
After exiting from the coalesces element 40, the process fluid
may be discharged from the housing as is, or it may be subjected
to additional types of fluid treatment. For example, the process
fluid may be passed through a separator element which can
separate the coalesced component of the process fluid from the
non-coalesced component.
When the filter element 10 requires replacement due, for
example, to having become loaded with particles removed from the
process fluid, the retaining nut 80 can be unscrewed from the
upper end cap 60 of the coalesces element 40, and the filter
element 10 can be withdrawn from the interior of the coalesces
element 40 to be replaced with a new filter element 10. The
coalesces element 40 can remain installed in the housing of the
fluid treatment system while the filter element 10 is being
replaced, or the two elements 10, 40 can be together removed from
the fluid treatment system.
Figure 4 is a cross-sectional elevation of another
embodiment of a fluid treatment assembly according to the present
invention. This embodiment is similar to the embodiment of
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Figure 1-3 but employs a different retaining member for
restricting lengthwise movement of a filter element 10 with
respect to a coalescer element 40. The upper cap 90 of the
coalescer element 40 is similar to the upper end cap 60 of the
coalescer element 40 of the embodiment of Figure 1, but the
external threads of end cap 60 have been replaced with portions
which can engage with portions of a retainer 100 by a snap fit.
In the present embodiment, the engaging portions of the upper end
cap 90 of the coalescer element 40 comprise one or more recesses
91 formed on the exterior of a neck of the end cap 90, and the
engaging portions of the retainer 100 comprise one or more jaws
101 which can snap into the recesses 91 of the upper end cap 90
of the coalescer element 40. Alternatively, the upper end cap 90
of the coalescer element 40 may be equipped with jaws or other
outward projections which can snap into recesses formed in the
retainer 100. The recesses 91 and the jaws 101 may extend around
all or a portion of the circumference of the upper end cap 90 and
the retainer 100, respectively. For example, the retainer 100
may be an annular member which extends around the entire
periphery of the upper end cap 90. As shown in Figure 5, which
is an isometric view of the retainer 100, in the present
embodiment, the retainer 100 comprises an elongated member which
extends diametrically across the upper end cap 90. It has a
generally rectangular shape as viewed in plan and an upper wall
102 with an opening 103 through which the handle 31 of the upper
end cap of the filter element 10 can pass. The upper wall 102
can contact the upper surface of the upper end cap 30 of the
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CA 02278961 1999-11-04
filter element 10 to prevent the filter element 10 from moving
far enough to become unsealed from the coalescer element 40. The
retainer 100 may further include a pair of handles 104 which
extend upwards from the upper wall 102. When the handles 104 are
squeezed towards each other, the retainer 100 will flex in a
direction causing the jaws 101 to spread apart from each other
and making it easier to detach the retainer 100 from the upper
end cap 90 of the coalescer element 40. The structure of this
embodiment may be otherwise the same as that of the embodiment of
Figure 1.
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