U.S. patent number RE44,424 [Application Number 13/088,937] was granted by the patent office on 2013-08-13 for filter assembly and method.
This patent grant is currently assigned to SPX Flow Technology USA, Inc.. The grantee listed for this patent is James W. Barnwell. Invention is credited to James W. Barnwell.
United States Patent |
RE44,424 |
Barnwell |
August 13, 2013 |
Filter assembly and method
Abstract
A filter assembly comprising a filter head having inlet and
outlet ports; a filter bowl attached to the filter head, wherein
the filter bowl has a drain hole located at the bottom of the
filter bowl for draining fluids; a filter element housed within the
filter bowl, the filter element including a barrier of filtration
media, a drain layer and at least one support tube; wherein a
pressure differential exists across the filter element; a bottom
cap that seals fluid within the filter element; a top cap having a
non-planar flange portion, wherein the flange portion has a
substantially curving, generally s-shaped cross-sectional profile,
the non-planar flange sealingly received within the filter head
such that the filter head is divided into inlet and outlet
partitions; wherein the top cap directs fluid from the inlet port
into the filter element, where the fluid flows through the barrier
of filtration media and then out of the assembly through the outlet
port; and, a float drain component attached to the base of the
filter bowl and aligned with the drain hole for controlling a
condensed fluid level within the assembly.
Inventors: |
Barnwell; James W. (Moravian
Falls, NC) |
Applicant: |
Name |
City |
State |
Country |
Type |
Barnwell; James W. |
Moravian Falls |
NC |
US |
|
|
Assignee: |
SPX Flow Technology USA, Inc.
(Ocala, FL)
|
Family
ID: |
40259979 |
Appl.
No.: |
13/088,937 |
Filed: |
April 18, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
11826474 |
Jul 16, 2007 |
7618480 |
Nov 17, 2009 |
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Current U.S.
Class: |
95/273; 210/443;
55/DIG.17; 55/423; 55/510; 55/498; 210/444; 55/504; 55/502;
55/486 |
Current CPC
Class: |
B01D
46/003 (20130101); B01D 46/2411 (20130101); B01D
46/0041 (20130101); B01D 46/4254 (20130101); B01D
46/0086 (20130101); B01D 2201/296 (20130101); Y10S
55/17 (20130101) |
Current International
Class: |
B01D
46/00 (20060101) |
Field of
Search: |
;55/418,421,423,486,487,498,502,504,505,507,508,510 ;95/273
;210/443,444,452 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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4335451 |
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1042045 |
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May 2004 |
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EP |
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1042044 |
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1042046 |
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1042047 |
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Feb 2005 |
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1297880 |
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970826 |
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2408223 |
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Dec 2006 |
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GB |
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H0437519 |
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Mar 1992 |
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JP |
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5015929 |
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Apr 1993 |
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JP |
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7328364 |
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JP |
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4624553 |
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Feb 2011 |
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JP |
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4781607 |
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Sep 2011 |
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JP |
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Other References
European Search Report issued on Jul. 11, 2012 for Application
Serial No. 12158175.5. cited by applicant .
Japanese Office Action issued on Feb. 28, 2012 for Application
Serial No. 2010-517048. cited by applicant .
Japanese Office Action dated May 15, 2013. cited by
applicant.
|
Primary Examiner: Clemente; Robert
Attorney, Agent or Firm: Baker & Hostetler LLP
Claims
What is claimed is:
1. A method of directing flow through a filter assembly,
comprising: directing flow of a fluid into an inlet port located
within a filter head of the filter assembly; passing the fluid from
the inlet port into a filter element using a top cap having a
non-planar flange portion, wherein the flange portion has a
substantially curving, generally s-shaped cross-sectional profile
to reduce the pressure loss at the inlet and outlet portions of the
filter head, the non-planar flange sealingly received within the
filter head such that the filter head is divided into inlet and
outlet partitions; passing the fluid through components of the
filter element housed within the filter bowl, the filter element
including a barrier of filtration media, a drain layer and at least
one support tube; wherein a pressure differential exists across the
filter element; preventing fluid from escaping from a bottom
portion of the filter bowl with a bottom cap; passing the fluid
through the barrier of filtration media and then out of the
assembly through the outlet port; and, controlling a fluid level
within the assembly using a float drain component attached to the
base of the filter bowl and aligned with a drain hole.
2. The method of directing flow through a filter assembly of claim
1, further comprising measuring the pressure differential across
the filter element.
3. The method of directing flow through a filter assembly of claim
1, further comprising capillary draining of liquid drops that
escape the drain layer using inner ribs running axially along an
inside surface of the filter bowl.
4. The method of directing flow through a filter assembly of claim
1, further comprising hand tightening the filter bowl to the filter
head using outer ribs running along an outside surface of the
filter bowl.
5. The method of directing flow through a filter assembly of claim
1, further comprising forming a pressurized attachment between the
filter bowl and the filter head.
6. The method of directing flow through a filter assembly of claim
1, further comprising minimizing re-entrainment of coalesced fluid
using a baffle located along the bottom inner portion of the filter
bowl.
7. The method of directing flow through a filter assembly of claim
1, further comprising connecting the filter assembly to at least
one other filtration apparatus using a plurality of ganging
clamps.
8. The method of directing flow through a filter assembly of claim
1, further comprising clipping the filter element using a
compression tab.
9. The method of directing flow through a filter assembly of claim
1, further comprising sealing the filter head to the top cap using
a compression tab.
10. A filter assembly comprising: a filter head having inlet and
outlet ports; a filter bowl attached to the filter head, wherein
the filter bowl has a drain hole located at a bottom of the filter
bowl for draining fluids; a filter element housed within the filter
bowl, the filter element including a barrier of filtration media, a
drain layer and at least one support tube; wherein a pressure
differential exists across the filter element; a bottom cap that
prevents fluid from escaping from a bottom portion of the filter
element; a top cap having a non-planar flange portion, wherein the
flange portion has a substantially curving, generally s-shaped
cross-sectional profile, the non-planar flange sealingly received
within the filter head such that the filter head is divided into
inlet and outlet partitions; wherein the top cap directs fluid from
the inlet port into the filter element, where the fluid flows
through the barrier of filtration media and then out of the
assembly through the outlet port; and, a float drain component
attached to the base of the filter bowl and aligned with the drain
hole for controlling a fluid level within the assembly.
11. The filter assembly of claim 10, wherein the inlet and outlet
ports are generally inline with one another.
12. The filter assembly of claim 10, further comprising a pressure
gauge having pressure sensors attached to the filter head for
measuring the pressure differential across the filter element.
13. The filter assembly of claim 12, wherein the filter head
includes sensor ports for attaching the pressure sensors within the
filter head.
14. The filter assembly of claim 10, wherein the filter head
includes a slanted inner top surface for decreasing a volume of the
filter head.
15. The filter assembly of claim 10, wherein the filter bowl
includes inner ribs running axially along an inside surface of the
filter bowl for capillary draining of liquid drops that escape the
drain layer.
16. The filter assembly of claim 10, wherein the filter bowl is in
threaded attachment with the filter head.
17. The filter assembly of claim 16, wherein the filter bowl
includes outer ribs running along an outside surface of the filter
bowl for improved hand tightening and loosening of the threaded
attachment.
18. The filter assembly of claim 10, wherein the filter bowl
includes an o-ring groove located along an upper outer surface of
the filter bowl for forming a pressurized attachment between the
filter bowl and the filter head.
19. The filter assembly of claim 10, wherein the filter bowl
includes a baffle located along a bottom inner portion of the
filter bowl for minimizing re-entrainment of coalesced liquids.
20. The filter assembly of claim 10, wherein the filter bowl
includes a sight glass for viewing the condensed fluid level.
21. The filter assembly of claim 10, further comprising a cosmetic
cover configured to mate with a top outer surface of the filter
head.
22. The filter assembly of claim 10, further comprising a plurality
of ganging clamps for connecting the filter assembly to at least
one other filtration apparatus.
23. The filter assembly of claim 10, wherein the float drain
includes a high-density foam float.
24. The filter assembly of claim 10, further comprising at least
one compression tab configured to maintain a compression seal
between the filter head and the top cap.
25. The filter assembly of claim 10, further comprising at least
one compression tab configured to position the filter element.
26. The filter assembly of claim 10, wherein the pressure
differential is reduced due to the construction of the element top
cap.
27. The filter assembly of claim 10, further comprising a bleed
orifice configured to whistle a warning signal when there is an
attempt to disassemble the assembly while it is under pressure.
28. The filter assembly of claim 10, wherein the flange portion
incorporates a modified venturi.
29. The filter assembly of claim 10, wherein the filtration media
includes at least one of the following: borosilicate glass fibers,
activated carbon fibers, .Iadd.granular activated carbon particles,
.Iaddend.polyester fibers, polypropylene fibers, nylon fibers and
spun bonded scrim.
30. A filter assembly comprising: filter head means for containing
inlet and outlet ports; filter element means for housing:
filtration media means for causing separation of fluids, drain
layer means for removing coalesced fluids and at least one support
means for supporting the filtration media means; pressuring means
for maintaining a pressure differential across the filter element
means; filter bowl means for housing the filter element, wherein
the filter bowl means is attached to the filter head means; bottom
cap means for sealing fluid within a bottom portion of the filter
element means; top cap means for dividing the filter head into
inlet and outlet partitions; wherein the top cap means includes a
non-planar flange portion, wherein the flange portion has a
substantially curving, generally s-shaped cross-sectional profile,
the non-planar flange sealingly received within the filter head;
wherein the top cap means directs fluid from the inlet port into
the filter element means, where the fluid flows through the
filtration media means and then out of the assembly through the
outlet port; and draining means for draining fluids coalesced
within the draining layer means.
.Iadd.31. The method of directing flow through a filter assembly of
claim 1, wherein the filter head includes a slanted inner top
surface for decreasing a volume of the filter head..Iaddend.
.Iadd.32. The method of directing flow through a filter assembly of
claim 4, wherein the filter bowl is in threaded attachment with the
filter head..Iaddend.
.Iadd.33. The method of directing flow through a filter assembly of
claim 1, wherein the filter bowl includes a sight glass for viewing
the condensed fluid level..Iaddend.
.Iadd.34. The method of directing flow through a filter assembly of
claim 1, wherein a cosmetic cover is configured to mate with a top
outer surface of the filter head..Iaddend.
.Iadd.35. The method of directing flow through a filter assembly of
claim 1, wherein the float drain includes a high-density foam
float..Iaddend.
.Iadd.36. The method of directing flow through a filter assembly of
claim 1, wherein the pressure differential is reduced due to the
construction of the element top cap..Iaddend.
.Iadd.37. The method of directing flow through a filter assembly of
claim 1, wherein the filter assembly comprises a bleed orifice
configured to whistle a warning signal when there is an attempt to
disassemble the assembly while it is under pressure..Iaddend.
.Iadd.38. The method of directing flow through a filter assembly of
claim 1, wherein the flange portion incorporates a modified
venturi..Iaddend.
.Iadd.39. The method of directing flow through a filter assembly of
claim 1, wherein the filtration media includes at least one of the
following: borosilicate glass fibers, activated carbon fibers,
granular activated carbon particles, polyester fibers,
polypropylene fibers, nylon fibers, and spun bonded
scrim..Iaddend.
.Iadd.40. A top cap of a filter assembly, comprising: a
funnel-shaped body to direct flow into a filter element of the
filter assembly; and a top surface comprising a non-planar flange
portion having a generally s-shaped cross-sectional
profile..Iaddend.
.Iadd.41. The top cap of claim 40, wherein the non-planar flange
portion is arranged within a filter head of the filter assembly
such that the filter head is divided into inlet and outlet
portions..Iaddend.
.Iadd.42. A replacement portion of a filter assembly, comprising: a
top cap to transition fluid into the filter assembly, a top surface
of the top cap comprising a non-planar flange portion having a
generally s-shaped cross-sectional profile; a filter element
comprising the filter media; and a bottom cap configured to inhibit
the fluid from flowing through the filter element without being
filtered..Iaddend.
.Iadd.43. The replacement portion of claim 42, wherein the
non-planar flange portion is arranged within a filter head of the
filter assembly such that the filter head is divided into inlet and
outlet portions..Iaddend.
.Iadd.44. A filter comprising: a top cap having a substantially
curved, non-planar flange portion, the non-planar flange sealingly
received within a filter head of a filter assembly such that the
filter head is divided into inlet and outlet portions and the
non-planar flange having generally s-shaped cross-sectional
profile..Iaddend.
Description
FIELD OF THE INVENTION
This invention relates generally to a filter assembly and method
for improving flow through the assembly. More particularly, the
present invention relates, for example, to a fluid filter assembly
having a non-planar flange for directing flow through the
assembly.
BACKGROUND OF THE INVENTION
It is known in the art that hydraulic and pneumatic filters may be
used to remove particulates, oils and water vapor from fluid
mixtures. These filters may also be used to remove odors from
breathing air. It is known in the art that compressed air, which
has several uses including in food packaging, pharmaceutical labs
and integrated circuit manufacturing, may be treated to remove
contaminants and water vapor. For instance, in circuit design, it
is critical for the compressed air to be devoid of oils and water
vapor which can cause a short circuit. Compressed air is treated
before use in manufacturing systems to remove water vapor and
contaminants from the air that may spoil the end product or at
least increase the cost of production by robbing the system of
power and efficiency.
Conventional filters, which are used in various applications such
as in treating compressed air, may contain a two-piece housing
including a filter head and an elongated tubular filter housing. An
elongated tubular element is typically removably located within the
housing, the tubular elements having annular end caps sealingly
bonded at each end of a ring-shaped media. These filters also
include a diverter or elbow structure which may direct flow into
the filter and provide a means for separating the head casting into
inlet and outlet streams, respectively connected to the inner and
outer portions of the elongated tubular element.
More recently, filters have utilized a top cap that serves the
function of a diverter. These top caps may have a truncated
funnel-like configuration removably located within a cylindrical
cavity of the head casting. The flow passes through the filter
element, which may consist of a media or membrane designed to
prevent undesired substances from flowing through the element into
the filtrate product stream. Accordingly, filtrate that flows
through the media then continues through the outlet port within the
head casting. In coalescing filters, the media causes certain
condensed liquid components to coalesce and combine the coalesced
droplets out of the gaseous product stream while solid particles
are trapped by sieving, impaction or Brownian motion.
The shape of the inlet-side surface of the top cap controls the
flow geometry of the inlet flow into the element. Similarly, the
outlet-side surface of the top cap controls the outlet flow. When
the inlet stream directly impacts a wall portion of the top cap,
the impact causes turbulence in the fluid flow. As a result, the
kinetic energy of the fluid is decreased which increases the
velocity of the fluid as it enters the filter element. These
filters have included a top cap having a planar flange section
which affects inlet flow from the head casting into the filter
element. The flange may tend to reduce the effects of turbulence by
decreasing the energy of the fluid and disturbing the velocity of
the fluid as it enters the filter element. However, the planar
flange may still result in turbulent flow in the inlet and outlet
streams.
Accordingly, it is desirable to provide a fluid filter assembly
having a flange which has inlet-side and outlet-side surfaces that
enable more laminar flow of fluid directly into and out of the
filter assembly. It is desirable to decrease turbulence because of
the pressure drop and also because turbulence causes re-entrainment
of condensed fluid in coalescing filters.
SUMMARY OF THE INVENTION
The foregoing needs are met, to a great extent, by the present
invention, wherein aspects of a fluid filter assembly having a
non-planar flange portion may be used for directing flow through
the assembly. Example embodiments of the present invention provide
improved flow through a filter element top cap that to a greater
extent incorporates a "modified venturi" having a generally
diagonal entrance with non-planar surface facing the process flow
inlet for in-to-out flow through the element. As such, the novel
top cap allows for a smoother transition into the media resulting
in lower overall pressure loss. The fluid filter assembly of the
present invention enables an inlet connection that directs the
process gas directly into the vessel without the use of an elbow or
diverter or other similar flow restriction device.
Example embodiments of the present invention relate to a filter
assembly having a filter head having inlet and outlet ports; a
filter element housed within a filter bowl, wherein a pressure
differential exists across the filter element. In example
embodiments, the pressure differential, which may be from 0 to 10
pounds per square inch (psi) or greater, is reduced. In example
embodiments, a compression tab configured to maintain a compression
seal between the filter head and the top cap may be used. A
compression tab may also be configured to position the filter
element. A bleed orifice may be configured to whistle a warning
signal when there is an attempt to disassemble the assembly while
it is under pressure.
The filter element may include a barrier of filtration media, a
drain layer and at least one support tube. The assembly may also
include a bottom cap that seals fluid within the filter element and
a top cap a top cap having a non-planar flange portion, wherein the
flange portion has a substantially curving, generally s-shaped
cross-sectional profile. The flange portion incorporates a modified
venturi for improved flow of both inlet and outlet streams through
the filter assembly. In example embodiments, the non-planar flange
is sealingly received within the filter head such that the filter
head is divided into inlet and outlet partitions; wherein the top
cap directs fluid from the inlet port into the filter element,
where the fluid flows through the barrier of filtration media and
then out of the assembly through the outlet port.
The filtration media may include at least one of the following:
borosilicate glass fibers, activated carbon fibers, polyester
fibers, polypropylene fibers, nylon fibers, spun bonded scrim or
similar media. Depending on the media used, liquid mists, fine
particulates and/or hydrocarbon vapors may be removed from the
fluid stream. In example embodiments, the filter assembly may also
include a drain hole located in the bottom of the filter bowl for
draining liquids. A float drain component, which may include a
high-density foam float, is attached to the base of the filter bowl
for draining fluids that escape the drain layer.
In example embodiments of the present invention, the inlet and
outlet ports of the filter assembly may be generally inline with
one another, which is preferable in compressed gas applications.
The assembly may also include a pressure gauge having pressure
sensors attached to the filter head for measuring the pressure
differential across the filter element. The filter head could
include sensor ports for attaching the pressure sensors within the
filter head. In example embodiments, the filter bowl is in threaded
attachment with the filter head. The filter bowl may then include
outer ribs running along an outside surface of the filter bowl for
improved hand tightening and loosening of the threaded attachment.
The filter head may include a slanted inner top surface for
decreasing a volume of the filter head, which is preferable in
certain applications.
In example embodiments of the present invention, the filter bowl
includes inner ribs running axially along an inside surface of the
filter bowl for capillary draining of liquid drops that escape the
drain layer. The filter bowl may include an o-ring groove located
along an upper outer surface of the filter bowl for forming a
pressurized attachment between the filter bowl and the filter head.
This o-ring seal isolates the threads from the fluid reducing the
possible corrosive effect on the threads. Additionally, the filter
bowl may include a baffle located along a bottom inner portion of
the filter bowl for quieting the gas to minimize re-entrainment of
coalesced liquids. The filter bowl may also include a sight glass
for viewing the fluid level.
In some embodiments of the filter assembly of the present
invention, a cosmetic cover is configured to mate with a top outer
surface of the filter head. When it is desirable to use more than
one filtration apparatus, a plurality of ganging clamps may be used
for connecting the filter assembly to at least one other filtration
apparatus.
Further contemplating in this invention is a method of directing
flow through a filter assembly, comprising: directing flow of a
fluid into an inlet port located within a filter head of the filter
assembly; passing the fluid from the inlet port into a filter
element using a top cap having a non-planar flange portion, wherein
the flange portion has a substantially curving, generally s-shaped
cross-sectional profile to reduce the pressure loss at the inlet
and outlet portions of the filter head, the non-planar flange
sealingly received within the filter head such that the filter head
is divided into inlet and outlet partitions; passing the fluid
through components of the filter element housed within the filter
bowl, the filter element including a barrier of filtration media, a
drain layer and at least one support tube; wherein a pressure
differential exists across the filter element; preventing fluid
from escaping from a bottom portion of the filter bowl with a
bottom cap; passing the fluid through the barrier of filtration
media and then out of the assembly through the outlet port; and,
controlling a fluid level within the assembly using a float drain
component attached to the base of the filter bowl and aligned with
a drain hole.
The method of directing flow through a filter assembly may also
include measuring the pressure differential across the filter
element. The method of directing flow through a filter assembly may
also include capillary draining of liquid drops that escape the
drain layer using inner ribs running axially along an inside
surface of the filter bowl. The method of directing flow through a
filter assembly may also include hand tightening of the filter bowl
to the filter head using outer ribs running along an outside
surface of the filter bowl. Furthermore, a pressurized attachment
between the filter bowl and the filter head may be formed.
In example embodiments of the method of directing flow through a
filter assembly in accordance with the present invention, the
method also includes minimizing re-entrainment of coalesced fluid
using a baffle located along the bottom inner portion of the filter
bowl. The method may also include connecting the filter assembly to
at least one other filtration apparatus using a plurality of
ganging clamps that align the various filter housings. The method
of directing flow through a filter assembly of claim 21, further
comprising clipping the filter element using one or more
compression tab(s) and sealing the filter head to the top cap using
compression tab(s).
In example embodiments of the present invention, a filter assembly
may include: filter head means for containing inlet and outlet
ports; filter element means for housing: filtration media means for
causing separation of fluids, drain layer means for removing
coalesced fluids and at least one support means for supporting the
filtration media means; pressuring means for maintaining a pressure
differential across the filter element means; filter bowl means for
housing the filter element, wherein the filter bowl means is
attached to the filter head means; bottom cap means for sealing
fluid within a bottom portion of the filter element means; top cap
means for dividing the filter head into inlet and outlet
partitions; wherein the top cap means includes a non-planar flange
portion, wherein the flange portion has a substantially curving,
generally s-shaped cross-sectional profile, the non-planar flange
sealingly received within the filter head; wherein the top cap
means directs fluid from the inlet port into the filter element
means, where the fluid flows through the filtration media means and
then out of the assembly through the outlet port; and draining
means for draining fluids coalesced within the draining layer
means.
There has thus been outlined, rather broadly, certain embodiments
of the invention in order that the detailed description thereof
herein may be better understood, and in order that the present
contribution to the art may be better appreciated. There are, of
course, additional embodiments of the invention that will be
described below and which will form the subject matter of the claim
appended hereto.
In this respect, before explaining at least one embodiment of the
invention in detail, it is to be understood that the invention is
not limited in its application to the details of construction and
to the arrangements of the components set forth in the following
description or illustrated in the drawings. The invention is
capable of embodiments in addition to those described and of being
practiced and carried out in various ways. Also, it is to be
understood that the phraseology and terminology employed herein, as
well as the abstract, are for the purpose of description and should
not be regarded as limiting.
As such, those skilled in the art will appreciate that the
conception upon which this disclosure is based may readily be
utilized as a basis for the designing of other structures, methods
and systems for carrying out the several purposes of the present
invention. It is important, therefore, that the claims be regarded
as including such equivalent constructions insofar as they do not
depart from the spirit and scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a filter assembly having a
non-planar flange, according to an embodiment of the present
invention.
FIG. 2 provides an exploded view of the inner components of the
filter assembly of FIG. 1.
FIG. 3A provides a plan view of the filter assembly of FIG. 1.
FIG. 3B provides a plan view of the filter assembly of FIG. 1
without the differential pressure gauge.
FIG. 4A provides an angled plan view of the top of the filter head
of the filter assembly of FIG. 1.
FIG. 4B provides an angled plan view of the bottom of the filter
head of the filter assembly of FIG. 1.
FIG. 5 provides a perspective view of a cosmetic cap for the filter
assembly of FIG. 1.
FIG. 6A provides a partially cutaway view of the interior of the
filter bowl of the filter assembly of FIG. 1.
FIG. 6B provides a frontal view of the exterior of the filter bowl
of the filter assembly of FIG. 1.
FIG. 6C provides a topical view of the interior of the filter bowl
of the filter assembly of FIG. 1.
FIG. 7 provides a plan view of the filter assembly of FIG. 1 having
ganging clamps attached to the inlet and outlet ports.
DETAILED DESCRIPTION
Various embodiments of the present invention provide for a fluid
filter assembly having a non-planar flange portion for directing
flow directly into the assembly without the use of an elbow or
similar flow restriction device. In some arrangements, the present
invention may be utilized in a compressed air or gas system, for
example. It should be understood, however, that the present
invention is not limited in its application to compressed air
systems, but may have application in other fluid separation systems
that utilize a filter assembly having a head containing both inlet
and outlet ports. Embodiments of the invention will now be further
described with reference to the drawing figures, in which like
reference numbers refer to like parts throughout.
FIG. 1 is a cross-sectional view of the filter assembly 100,
according to an embodiment of the present invention. In example
embodiments of the present invention, filter assembly 100 having a
non-planar flange portion 105 is provided. Example embodiments of
the filter assembly 100 include a filter bowl 115, a tapered filter
head 120, a top cap 135 having a non-planar flange portion 105, a
bottom cap 150, and a filter element 110, which includes: a filter
media 112 surrounded by support tubes 140, and a drain layer 117,
which is the outer most layer of the filter element 110.
Additionally, a float drain 141 having a closed cell rigid foam
float may be attached to the bottom of the bowl 115 to adjust the
fluid level within the filter. The float drain 141 includes a float
hole 143 that can open and close depending on the level of the
float at the bottom of the bowl 115 (discussed further below).
The filter bowl 115 may be threaded with a tapered filter head 120,
which includes both threaded inlet and outlet ports, 125 and 130,
respectively. The inlet and outlet ports, 125 and 130,
respectively, may be generally inline with each other, as shown in
FIG. 1, for ease of assembly into a compressed air or gas system.
This is because multiple filter assemblies 100 are often used in
compressed gas systems, and it is easier to connect assemblies 100
in series when the inlet and outlet ports 125 and 130 share the
same center line. As such, no elbow or diverter is needed to
connect the multiple filter assemblies 100 and thus, piping the
series of assemblies will be made easier and cheaper from a
manufacturing standpoint.
In example embodiments of the present invention, a pressure
differential exists across the inlet and outlet ports, 125 and 130.
In example embodiments, the differential pressure may be from 0 to
10 pounds per square inch (psi) or greater. The filter assembly 100
may also include pressure sensors 134a, positioned at the inlet and
outlet ports, 125 and 130, for measuring the pressure differential
across the filter element 110 using a pressure gauge 133. The
pressure at the inlet is higher than the pressure at the outlet
and, as such, fluid flows through the filter assembly 100 is driven
by the pressure differential. Because the process flow is
pressurized during operation, a bleed orifice 160 may be used in
such a way as to whistle a warning in the case that an attempt is
made to disassemble the assembly 100 while it is under
pressure.
In example embodiments of the present invention, the assembly 100
includes top cap 135 having a funnel-like configuration for
directing flow into the filter element 110. The top cap 135 is
generally horn-shaped, allowing for a smooth transition of the flow
into the media 112 resulting in lower overall pressure loss across
the inlet and outlet streams. The top surface of top cap 135 may
have a curved lip portion described as non-planar flange portion
105. The non-planar flange portion 105 incorporates a "modified
venturi" having a generally diagonal entrance facing the process
flow inlet for improved in-to-outflow through the filter element
110. The non-planar flange portion 105 is generally s-shaped, or
shaped like an ogee, wherein a top-most end 105a and a bottom-most
end 105b of the non-planar flange portion 105 are substantially
perpendicular with the inner side wall of the filter head 120 and
therefore, form a seal with the inner side wall.
In example embodiments of the present invention, a seal 137 is
formed between the top cap 135 and the filter head 120 by mating
the top cap 135 with the inner wall of the filter head 120 along
the non-planar flange portion 105 to form seal 137, as shown in
FIG. 1. Accordingly, all the process flow is driven down into the
element 110. In example embodiments of the present invention, the
filter assembly 100 also includes a bottom cap 150 for sealing
fluid within the filter element 110, thereby forcing all fluid that
enters the filter element 110 to pass through the filter media 112
from the inside out.
In example embodiments of the present invention, seal 137 may be
formed with the help of a compression tab 145 on the bottom portion
of the top cap 135. The compression tab 145 serves the dual purpose
of maintaining the proper squeeze (pressure) on the seal 137 while
also ensuring proper positioning of the filter element 110 during
assembly of the filter assembly 100. In example embodiments of the
present invention, a compression tab 145 may be located below the
outlet port 130. The compression tab 145 may apply a squeeze to the
top cap 135 at the top-most 105a and bottom-most ends 105b of the
non-planar flange portion 105. In some embodiments, the compression
tab 145 may become seated against the filter bowl 115 due to being
pushed down as a result of the pressure differential.
The compression tab 145 is seated such that it encloses the top
portion of each component of the filter element 110, as shown in
FIG. 1, to ensure that the inlet fluid flowing into the filter
element 110 and out through the media 112. The compression tab 145
positions the filter element 110, ensuring that the required force
for sealing the filter element 110 within the assembly 100 is
applied. The compression tab 145 is positioned to sit just above
the top edge of the bowl 115 once the filter has been assembled so
as to keep the element 110 from sliding downward and breaking the
pressurized seal. In other embodiments of the present invention,
the filter assembly 100 may include more than one compression tab
145.
FIG. 2 provides an exploded view of the inner components of the
filter assembly of FIG. 1. These inner components include the top
cap 135, the bottom cap 150 and the individual components of the
filter element 110. In addition to the compression tab 145, the top
cap 135 may have a groove 207, as shown in FIG. 2, for an o-ring
(not shown) which may also be used to help maintain the seal 137.
This o-ring seal isolates the threads, which are used in attaching
the filter head 120 to the bowl 115, from the fluid reducing the
possible corrosive effect on the threads.
The bottom cap 150, used to prevent fluid from flowing through the
filter element 110 without passing through the media 112, may also
have an outer lip portion 150a which mates to form a seal with the
drain layer 117 and an inner lip portion 150b which is sized to fit
within the inner surface of the filter media 112. The bottom end
cap 150 is solid (closed off) effectively sealing fluid within the
filter element 110, such that all fluid that enters the filter
assembly 100 must pass radially through the filter media 112 or in
the case of a granular type bed of media, the bottom end cap 150
may be open allowing axial flow through the bed. The bottom cap 150
may be adhered to the drain layer 117 using epoxy adhesive or
urethane adhesive to seal.
In example embodiments of the present invention, the filter element
110 may be housed within the filter bowl 115 and which encloses:
the filter media 112 surrounded by porous, louvered or perforated
metal support tubes 140; the top cap 135 and the bottom end cap
150. The filter may include one, two or more porous, louvered or
perforated support tubes 140 designed to support the inner and/or
the outer surfaces of a filter media 112 without impeding flow
through the filter element 110 while rigidly linking the top cap to
the bottom cap. In example embodiments, the filter element 110
includes two support tubes, as shown in FIG. 2. The support tubes
140 may be made of metal or plastic or alternatively, a wire screen
that is suitable for providing support to the filter media 112 may
be used.
In example embodiments of the present invention, the filter media
112 may be cylindrical wrapped and/or pleated media or
alternatively a granular bed of media. The filter media may be made
of borosilicate glass and/or various hydrocarbon based materials
depending on the desired filtration. A common media is made of
borosilicate glass fibers treated with hydrophobic and or
oleophobic matter to assist in the coalescing of contaminants and
trapping of particulates. In example embodiments of the present
invention, several different grades of borosilicate glass or
nanofibers may be added to progressively remove solid particulates
in the fluid inlet stream in addition to causing fluids to coalesce
out of the fluid inlet stream as it passes through the media
112.
In example embodiments of the present invention, in addition to or
instead of coalescing media, activated carbon may be used within
the media 112 in order to remove contaminants, such as organic
vapors, and odors from the fluid stream. The addition of activated
carbon may have application in systems for purifying breathing air,
for example.
Because pleating increases the surface area of the media 112 and
allows for more uniform air to flow through the media 112, spun
bonded polyester and nylon scrims may be added to assist in
pleating process and maintain separation between pleats of the
media 112. In example embodiments of the present invention, the
media may include at least: borosilicate glass fibers, activated
carbon fibers, polyester fibers, polypropylene fibers, nylon
fibers, spun bonded scrim and/or similar media.
FIG. 3A provides a plan view of the filter assembly of FIG. 1 and
FIG. 3B provides a plan view of the filter assembly of FIG. 1
without the differential pressure gauge. In example embodiments, a
differential pressure gauge 133, best shown in FIGS. 3A and 7,
measures the pressure differential across the filter element 110.
The sensors 134a of the gauge 133 are attached to the filter head
120 via ports 134b, as best shown in FIGS. 3A and 3B. An overall
pressure differential drives fluid that enters the assembly 100
through the filter element 110, from the inlet port 125 ultimately
out through the outlet port 130. The ports 134b may be threaded for
attachment of the pressure gauge 133 and sensors 134a. An o-ring
groove 344 for attachment of ganging clamps (not shown in FIGS. 3A
and 3B) may be found on the inlet and outlet ports 125 and 130.
Ganging clamps are used to attach multiple filter assemblies 100,
as discussed below.
In example embodiments of the present invention, the top outer
surface of the filter head 120 has a slanted cylindrical
configuration having a diagonal inner top surface 127, as shown in
FIGS. 1, 3A and 4A. The inner top surface 127 is slanted in order
to minimize the volume of the filter head 120, which may be desired
in certain applications. FIG. 4A provides an angled plan view of
the top of the filter head 120 of the filter assembly 100 and FIG.
4B provides an angled plan view of the bottom of the filter head
120 of the filter assembly 100. In example methods of using the
filter assembly, fluid enters the filter head 120 at the inlet port
125. The top inner surface of the filter head 120 has a sloped
portion 428 that curves to compliment the inlet port 125, as best
shown in FIG. 4B. The fluid outlet flows out of the filter head 120
through the outlet port 130. As would be appreciated by one of
ordinary skill in the art, the filter head 120 of the present
invention is novel in its simplicity because there is no need for a
diverter component to direct flow into and out of the filter
assembly 100.
In example embodiments, a cosmetic top cover 555, as best shown in
FIG. 5, may be fitted to compliment the slanted top surface 127 of
the filter head 120 for estedic reasons. The top cover 555 would
include access ports 557 for attaching sensors 134a to the
differential pressure gauge 133 through the filter head 120. The
top cover 555 may be made of plastic, metal or any other suitable
material. In example embodiments the cover is made of plastic.
Referring now to FIGS. 6A-6C, various views of the filter bowl 115
are provided. Another inventive feature of the present invention is
that, in example embodiments, the filter bowl 115 may contain
shallow inner ribs 665 running axially along the inside surface of
the filter bowl 115, as shown in FIGS. 6A and 6C, for capillary
draining of liquid drops that may escape the drain layer 117. For
instance, the inner ribs 665 may act as a capillary to drain oil
droplets that form on the inside wall of the filter bowl 115 as the
amount of oil within the drain layer 117 builds up. As such, the
inner ribs 665 force the oil droplets, using capillary action along
with gravitational force, to continue to flow down into the float
drain 141 and keep the coalesced oil from re-entraining in the
outlet fluid stream. In example embodiments of the present
invention, outer ribs 680 may be located on the outer surface of
the filter bowl 115 to aid in disassembling the filter housing by
hand, for instance, when the filter media 112 needs to be
replaced.
In example embodiments of the present invention, a baffle 670 may
be located along the bottom inner portion of the filter bowl 115
for enhancing dead air space to prevent re-entrainment of the
coalesced fluid into the product gas stream. The baffle 670
achieves this by minimizing air circulation that otherwise would
result in more turbulent air that would sweep unwanted coalesced
liquids back into the product gas stream. The baffle 670 also
ensures that the filter element 110 is maintained in a correct
position within the element 110. In other example embodiments, the
bottom cap 150 may be rested upon the baffle 670.
In example embodiments of the present invention, the filter bowl
115 may also include a drain hole 675 for draining fluids from the
filter assembly 100 through the float drain 141 which is attached
to the bottom of the filter bowl 115. The float drain 141 may have
a snap action for very reliable open/close feature to ensure that
none of the product stream may be lost from the outlet stream.
Additionally, a sight glass 684 (not shown) may be located near the
bottom of the bowl 115 for viewing the fluid level within the float
drain 141.
In example embodiments of the present invention, another o-ring
(not shown) or some similar sealing mechanism may be present to
complete the pressurized attachment between the filter bowl 115 and
the filter head 120. The o-ring seal may also have the effect of
preventing contaminants from reaching the attaching threads,
minimizing corrosion and galling in the threads. An o-ring groove
683 for seating the o-ring may be located at the top of the filter
bowl 115, as shown in FIG. 6B.
In example embodiments of the present invention, contaminated fluid
enters the filter head 120 of the filter assembly 100 through the
inlet port 125. The filter top cap 135 directs fluid from the inlet
port 125, along the inner surface of its horn-shaped structure, and
into the filter element 110. The inlet fluid would then flow
radially out through a cylindrical wrapped or pleated media 112 or
alternatively, the fluid could flow axially through a bed of
granular-type media 112. The product outlet gas stream would then
flow up through the annular space between the filter element 110
and housing 115, being smoothly directed by the bottom portion of
the element top cap 135 in the filter head 120 and out of the
filter assembly 100 through the outlet port 130.
In certain applications, the media 112 affects adsorption of
condensable hydrocarbons and odors within the inlet stream. In
coalescing filters, the drain layer 117 has an effect of
facilitating the effect of gravity in causing the condensed fluids
to drop down into the float drain 117 rather than flowing into the
outlet gas stream. The drain layer 117 may be made of open shell
foam or needle point felt like polyester or any other material
suitable for absorbing coalesced fluids.
The condensed fluid should be drained from the filter assembly 100
before the liquid level reaches the height of the filter element
110. When draining is needed, the float drain 141 lifts up to allow
liquid to drain out of the assembly 100. The mechanism of the float
drain 141 operates as snap valve, which in some embodiments is
magnetic, controlled by the high density foam float 141. When the
float 141 rises, as the fluid level rises to a certain height, the
valve opens to allow liquid to drain and then shuts off before any
product gases escape the filter assembly 100. In example
embodiments, the float drain 141 may have a brass stem with o-ring
seal for attachment into the filter bowl 115.
In certain applications, it may be desirable to use more than one
filter assembly 100 in series to achieve the required degree of
filtration. The filter assembly 100 may be attached to a second
assembly via ganging clamps 785 attached to inlet port 125 and
outlet port 130, as shown in FIG. 7. The ganging clamps 785 may
also have tapered sides 787 to "squeeze" the flanges 105 of each
filter assembly 100 together. The filter heads 120 include an
o-ring groove 344 to provide space for an o-ring (not shown) which
forms a seal between the inlet and outlet ports 125 and 130. In
these embodiments, the inlet and outlet ports 125 and 130 may have
alignment tabs 790 for facilitating the connection of the ganging
clamps 785 to the filter head 120. The ganging clamps would have a
complimentary indexing key 795 for mating with the alignment tabs
790. The ganging clamps may also include holes 797 for bracket
fasteners (not shown) which may be used in wall mounting the
assembly 100.
It is understood that, although the filter assembly 100 of the
present invention is described as relating to in-to-out flow
through the cylinder filter media, the filter assembly 100 may also
be reversed using out-to-in flow in some applications with similar
results in pressure loss and improved performance due to the
non-planar flange 105. For instance, out-to-in flow would be
appropriate in applications where there may be particulate high
dust loading capacity so that caked on dirt can drop to the bottom
of the bowl 115.
The many features and advantages of the invention are apparent from
the detailed specification, and thus, it is intended by the
appended claims to cover all such features and advantages of the
invention which fall within the true spirit and scope of the
invention. Further, since numerous modifications and variations
will readily occur to those skilled in the art, it is not desired
to limit the invention to the exact construction and operation
illustrated and described, and accordingly, all suitable
modifications and equivalents may be resorted to, falling within
the scope of the invention.
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