U.S. patent application number 11/531986 was filed with the patent office on 2007-02-01 for filter assembly and filter element.
Invention is credited to E. Bayne Carew.
Application Number | 20070023339 11/531986 |
Document ID | / |
Family ID | 22846713 |
Filed Date | 2007-02-01 |
United States Patent
Application |
20070023339 |
Kind Code |
A1 |
Carew; E. Bayne |
February 1, 2007 |
Filter Assembly And Filter Element
Abstract
A filter assembly and a method of filtering a fluid using the
filter assembly are disclosed. The filter assembly includes wave
coils arranged axially to define a filter element. The filter
element includes bottom and top ends and an inner cavity. The
filter assembly also includes a base plate that engages one, or
both, ends to support the wave coils. The fluid flows toward the
base plate, and the base plate diverts the fluid inside or outside
the inner cavity. The wave coils include crests and troughs
engaging one another on adjacent wave coils to define filtration
apertures. The diverted fluid is filtered through the filtration
apertures such that a filtrate of the fluid passes through the
inside or outside of the inner cavity, and a retentate of the fluid
is retained on the other of the inside or outside of the inner
cavity relative to the filtrate.
Inventors: |
Carew; E. Bayne; (Mildord,
MI) |
Correspondence
Address: |
HOWARD & HOWARD ATTORNEYS, P.C.
THE PINEHURST OFFICE CENTER, SUITE #101
39400 WOODWARD AVENUE
BLOOMFIELD HILLS
MI
48304-5151
US
|
Family ID: |
22846713 |
Appl. No.: |
11/531986 |
Filed: |
September 14, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10863798 |
Jun 8, 2004 |
7122123 |
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11531986 |
Sep 14, 2006 |
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09931510 |
Aug 16, 2001 |
6761270 |
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10863798 |
Jun 8, 2004 |
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60225895 |
Aug 17, 2000 |
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Current U.S.
Class: |
210/167.21 |
Current CPC
Class: |
B01D 29/15 20130101;
B01D 29/606 20130101; B01D 36/003 20130101; B01D 29/48 20130101;
B01D 29/906 20130101; B01D 29/23 20130101; B01D 29/902 20130101;
B01D 2201/0415 20130101; B01D 29/908 20130101; B01D 29/58 20130101;
A01K 63/045 20130101; B01D 29/925 20130101; B01D 29/668 20130101;
B01D 2201/184 20130101; B01D 37/025 20130101 |
Class at
Publication: |
210/167.21 |
International
Class: |
A01K 63/04 20060101
A01K063/04 |
Claims
1. A filter assembly for filtering a fluid, said assembly
comprising: a plurality of wave coils arranged axially to define a
filter element having first and second ends and an inner cavity; a
support engaging one of said first and second ends for supporting
said wave coils and for diverting the fluid inside or outside said
inner cavity of said filter element; and each of said wave coils
including at least one crest and at least one trough with said at
least one crest of one wave coil engaging said at least one trough
of an adjacent wave coil to define at least one filtration aperture
between each crest and each trough of adjacent wave coils for
filtering the fluid diverted by said support.
2. A filter assembly as set forth in claim 1 further comprising an
adjustment mechanism engaging at least one of said first and second
ends for modifying a length L, extending between said first and
second ends of said filter element, to reduce and expand said at
least one filtration aperture.
3. A filter assembly as set forth in claim 2 wherein said
adjustment mechanism is at least partially disposed in said inner
cavity of said filter element.
4. A filter assembly as set forth in claim 2 wherein said
adjustment mechanism comprises a base plate engaging one of said
first and second ends of said filter element.
5. A filter assembly as set forth in claim 4 wherein said support
is further defined as said base plate.
6-8. (canceled)
9. A filter assembly as set forth in claim 4 wherein said
adjustment mechanism further comprises a flange member engaging the
other of said first and second ends relative to said base plate,
said flange member being adjustably engaged relative to said base
plate for modifying said length L to reduce and expand said at
least one filtration aperture.
10. A filter assembly as set forth in claim 9 wherein said
adjustment mechanism further comprises an adjustment shaft
extending from said base plate to engage said flange member such
that said flange member is adjustable relative to said base plate
for modifying said length L of said filter element.
11-24. (canceled)
25. A filter assembly as set forth in claim 1 further comprising at
least one retention post extending through said inner cavity and
between said first and second ends of said filter element for
maintaining the axial arrangement of said wave coils.
26. A filter assembly as set forth in claim 1 wherein said wave
coils are further defined as a wave spring.
27. A filter assembly as set forth in claim 1 wherein each of said
wave coils comprises a shearing surface for imparting shear forces
on the fluid being filtered.
28. A filter assembly as set forth in claim 27 wherein said
shearing surfaces of said wave coils comprise a plurality of ridges
enhancing the shear forces imparted on the fluid being
filtered.
29. A filter assembly as set forth in claim 27 wherein said
shearing surfaces of said wave coils comprise a coating for
modifying a flow of the fluid being filtered.
30. A filter assembly as set forth in claim 1 wherein said wave
coils extend continuously in an endless path through said at least
one crest and said at least one trough and between said first and
second ends of said filter element.
31. A filter assembly as set forth in claim 30 wherein said wave
coils extend continuously in a helix through said endless path
between said first and second ends.
32. A filter assembly as set forth in claim 2 further comprising a
controller in communication with said adjustment mechanism such
that adjustment mechanism automatically modifies said length L of
said filter element to reduce and expand said at least one
filtration aperture.
33. A filter assembly as set forth in claim 32 further comprising
at least one pressure sensor in communication with said controller
for activating said adjustment mechanism to automatically reduce
and expand said at least one filtration aperture.
34. A filter assembly as set forth in claim 1 in combination with a
filter canister comprising an inlet for receiving the fluid to be
filtered and an outlet for delivering the fluid that has been
filtered, said filter assembly being disposed in said filter
canister.
35-41. (canceled)
42. A filter assembly as set forth in claim 34 wherein said inlet
of said filter canister is oval-shaped for imparting a vortex onto
the fluid received into said filter canister for filtering.
43. A filter assembly as set forth in claim 34 further comprising
an inlet valve disposed at said inlet of said filter canister for
isolating said filter canister from the fluid to be filtered.
44. A filter assembly as set forth in claim 43 further comprising a
controller in communication with said inlet valve for automatically
isolating said filter canister from the fluid to be filtered.
45. A filter assembly as set forth in claim 44 further comprising a
first pressure sensor disposed at said inlet of said filter
canister for determining an inlet pressure and a second pressure
sensor disposed at said outlet of said filter canister for
determining an outlet pressure wherein said first and second
pressure sensors are in communication with said controller such
that said controller activates said valve to isolate said filter
canister from the fluid to be filtered when said outlet pressure is
less than said inlet pressure by a predetermined amount.
46. A filter assembly as set forth in claim 45 further comprising
an outlet valve disposed at said outlet of said filter canister for
allowing said filter canister to selectively receive fluid for
back-washing said filter element when said outlet pressure is less
than said inlet pressure by said predetermined amount.
47. A filter assembly as set forth in claim 9 wherein said flange
member comprises; a fixed plate engaging the other of said first
and second ends relative to said base plate, and a sliding plate
being adjustably engaged relative to said fixed plate and for
modifying said length L of said filter element to reduce and expand
said at least one filtration aperture.
48. A filter assembly as set forth in claim 47 wherein said
adjustment mechanism further comprises a controller in
communication with said sliding plate for automatically adjusting
said sliding plate relative to said fixed plate.
49. A filter assembly as set forth in claim 1 further comprising at
least one baffle disposed within said inner cavity of said filter
element for directing the fluid toward said at least one filtration
aperture.
50. A filter assembly as set forth in claim 49 wherein said at
least one baffle is hollow such that a filtration additive be can
delivered to said at least one filtration aperture through said at
least one baffle.
51. A filter assembly as set forth in claim 50 wherein said
filtration additive delivered to said at least one filtration
aperture through said at least one baffle is steam.
52. A filter assembly as set forth in claim 1 further comprising a
plurality of said filter assemblies.
53. A filter assembly as set forth in claim 52 wherein said
plurality of said filter assemblies is arranged such that said
filter assemblies are in parallel.
54. A filter assembly as set forth in claim 52 wherein said
plurality of filter assemblies is arranged such that said filter
assemblies are in series.
55. A filter assembly as set forth in claim 52 wherein at least one
filter assembly of said plurality is disposed concentrically about
another filter assembly of said plurality in a nested
configuration.
56. A filter assembly as set forth in claim 55 further comprising a
plurality of beads disposed within said inner cavity of said filter
element for increasing a surface area of the fluid to be
filtered.
57. A filter element for filtering a fluid, said filter element
comprising: a plurality of wave coils arranged axially and having
first and second ends and an inner cavity; and said assembly
characterized by each of said wave coils including at least one
crest and at least one trough with said at least one crest of one
wave coil engaging said at least one trough of an adjacent wave
coil to define at least one filtration aperture between each crest
and each trough of adjacent wave coils for filtering the fluid.
58. A filter element as set forth in claim 57 in combination with
an adjustment mechanism engaging at least one of said first and
second ends for modifying a length L, extending between said first
and second ends of said filter element, to reduce and expand said
at least one filtration aperture.
59. (canceled)
60. A filter element as set forth in claim 57 wherein said wave
coils are further defined as a wave spring.
61. A filter element as set forth in claim 57 wherein each of said
wave coils comprises a shearing surface for imparting shear forces
on the fluid being filtered.
62. A filter element as set forth in claim 61 wherein said shearing
surfaces of said wave coils comprise a plurality of ridges
enhancing the shear forces imparted on the fluid being
filtered.
63. A filter element as set forth in claim 61 wherein said shearing
surfaces of said wave coils comprise a coating for modifying a flow
of the fluid being filtered.
64. A filter element as set forth in claim 57 wherein said wave
coils extend continuously in an endless path through said at least
one crest and said at least one trough and between said first and
second ends.
65. A filter element as set forth in claim 64 wherein said wave
coils extend continuously in a helix through said endless path
between said first and second ends.
66-75. (canceled)
Description
RELATED APPLICATIONS
[0001] The present application claims priority to and all
advantages of U.S. Provisional Patent Application No. 60/225,895,
which was filed on Aug. 17, 2000.
BACKGROUND OF THE INVENTION
[0002] 1) Field of the Invention
[0003] The subject invention generally relates to a filter assembly
and method of filtering utilizing the filter assembly to filter a
fluid. More specifically, the subject invention relates to an
adjustable filter assembly including a filter element and
filtration apertures that are defined between crests and troughs of
adjacent wave coils of the filter element wherein the filtration
apertures are adjustable.
[0004] 2) Description of Related Art
[0005] Spring filters are known in the art. Helically- or
spirally-wound spring filters are also known in the art. Examples
of such conventional spring filters are disclosed in U.S. Pat. Nos.
4,113,000; 4,199,454; and 5,152,892. Conventional spring filters,
including the helically- and spirally-wound spring filters
disclosed in the above-referenced patents, are deficient for
various reasons. For instance, certain conventional spring filters
are not adjustable. Other conventional spring filters are not
easily adjustable and are not easily manufactured. As one specific
example, the conventional spring filter disclosed in the '892
patent is deficient because the entire coil of this conventional
spring filter, which is made up of a plurality of individual flat
coils, is extremely weak having a k factor of about zero. As a
result, filtration gaps, or filtration apertures, can not be
maintained between the individual flat coils when the spring filter
is vertically-oriented. This conventional spring filter is also
particularly difficult to manufacture. More specifically, this
conventional spring filter requires that the individual flat coils
of the filter be manufactured such that the filtration apertures,
between adjacent flat coils progressively increase in size and
pitch which, as understood by those skilled in the art, is a
particularly cumbersome requirement. This conventional spring
filter further requires that projections be machined into each coil
to maintain a minimum filtration aperture between adjacent coils of
the filter, thus involving additional machining requirements and
even limits on size of the spring filter.
[0006] Due to the deficiencies identified in the spring filters of
the prior art, including those set forth above, it is desirable to
implement an adjustable filter assembly that is ideal to
manufacture and that uniquely defines a filtration aperture between
adjacent coils of a filter element for optimum filtering of fluids
due to the adjustability of the filtration aperture. It is also
desirable that the adjustable filter assembly according to the
subject invention can be easily manufactured into a wide range of
sizes and stiffnesses of the filter element.
SUMMARY OF THE INVENTION AND ADVANTAGES
[0007] A filter assembly and method of filtering utilizing the
filter assembly to filter a fluid are disclosed. The filter
assembly includes a plurality of wave coils. The wave coils include
at least one crest and at least one trough and are arranged axially
to define a filter element. The filter element includes first and
second ends and an inner cavity. The filter assembly also includes
a support that engages either the first or second end of the filter
element for supporting the wave coils. The support also diverts the
fluid inside or outside of the inner cavity of the filter element.
The crest of one wave coil engages the trough of an adjacent wave
coil to define at least one filtration aperture between each crest
and each trough of the adjacent wave coils.
[0008] The fluid flows toward the support such that the support
diverts the fluid to the inside or the outside of the inner cavity
of the filter element. The fluid diverted by the support is
filtered through the filtration apertures. More specifically, if
the fluid flows toward the support and is diverted to the inside of
the inner cavity and then through the filtration apertures, then a
filtrate of the fluid, which also flows through the filtration
apertures, passes through the outside of the inner cavity, and a
retentate of the fluid, which cannot flow through the filtration
apertures, is retained on the inside of the inner cavity of the
filter element. Alternatively, if the fluid flows toward the
support and is diverted to the outside of the inner cavity and then
through the filtration apertures, then the filtrate of the fluid
flows through the filtration apertures and passes through the
inside of the inner cavity, whereas the retentate of the fluid is
retained on the outside of the inner cavity of the filter
element.
[0009] Accordingly, the subject invention provides a filter
assembly that establishes a filtration aperture between adjacent
coils of a filter element included in the filter assembly.
Additionally, the filter assembly of the subject invention is
easily manufactured.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Other advantages of the present invention will be readily
appreciated as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings wherein:
[0011] FIG. 1A is a side view of a filter assembly illustrating a
plurality of filtration apertures defined between crests and
troughs of adjacent wave coils of a filter element of the
assembly;
[0012] FIG. 1B is a perspective view of the filter element of the
assembly illustrating the plurality of wave coils arranged axially
and defining an inner cavity;
[0013] FIG. 2A is an enlarged side view of a portion of the filter
element;
[0014] FIG. 2B is an enlarged side view of a wave coil having
crests and troughs;
[0015] FIGS. 3A through 3C are side views of various shearing
surfaces of wave coils including a plurality of ridges for
enhancing shear forces imparted on a fluid that is to be
filtered
[0016] FIG. 4 is an exploded perspective view of the filter
assembly in combination with a canister for filtering the
fluid;
[0017] FIG. 5A is a partially cross-sectional side view of the
filter assembly illustrating an inlet valve disposed at an inlet of
the filter canister and an outlet valve disposed at an outlet of
the filter canister;
[0018] FIG. 5B is a schematic representation of a backwash position
of the inlet valve at the inlet of the filter canister;
[0019] FIG. 6A is a partially cross-sectional side view of the
filter assembly disposed in the filter canister illustrating an
alternative adjustment mechanism including a manual adjustment
assembly for modifying a length L of the filter element to reduce
and expand the filtration apertures;
[0020] FIG. 6B is a enlarged, partially cross-sectional view of the
manual adjustment assembly that may be utilized in the adjustment
mechanism;
[0021] FIG. 7 is a partially cross-sectional side view of the
filter assembly disposed in the filter canister illustrating a
further alternative adjustment mechanism including a motor for
automatically modifying the length L of the filter element to
automatically reduce and expand the filtration apertures;
[0022] FIG. 8A is an exploded perspective view of two filter
assemblies in a nested configuration where one filter assembly is
disposed concentrically about another filter assembly;
[0023] FIG. 8B is an enlarged perspective view of a baffle cage
included in the nested configuration of FIG. 8A where individual
baffles are hollow such that a filtration additive can be delivered
to the filtration apertures;
[0024] FIG. 9 is a schematic view of filter assemblies arranged in
parallel and in series and illustrating a controller in
communication with the filter assemblies;
[0025] FIG. 10A is a schematic view of the fluid flowing through an
inside of the inner cavity such that a filtrate of the fluid flows
through the filtration apertures and through an outside of the
inner cavity, and a retentate of the fluid is retained on the
inside of the inner cavity; and
[0026] FIG. 10B is a schematic view of the fluid flowing through
the outside of the inner cavity such that the filtrate of the fluid
flows through the filtration apertures and through the inside of
the inner cavity, and the retentate of the fluid is retained on the
outside of the inner cavity.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Referring to the Figures, wherein like numerals indicate
like or corresponding parts throughout the several views, a filter
assembly for filtering a fluid is generally disclosed at 10. It is
to be understood that the filter assembly 10 and method of
filtering according to the subject invention are capable of
filtering both liquids and gases as the fluid. The filter assembly
10 of the subject invention is most preferably used to filter
fluids having solid particles including, but not limited to,
slurries of biological waste. As such, the filter assembly 10 is
commonly used in combination with such devices as shaker screens,
steam scrubbers and/or strippers, biofilters, conveyors, and as a
component in mobile filtration units.
[0028] As shown best in FIGS. 1A through 2B, the filter assembly 10
includes a plurality of wave coils 12. The plurality of wave coils
12 are formed from individual flat wave coils 12. The wave coils 12
include at least one crest 14 and at least one trough 16 and are
arranged axially to define a filter element 18. Although the wave
coils 12 need only include one crest 14 and one trough 16, the wave
coils 12 preferably include more than one crest 14 and more than
one trough 16 and will be described as such below.
[0029] The filter element 18 includes first 20 and second 22 ends
and an inner cavity 24. The filter element 18 also includes a
length L extending between the first and second ends 20, 22. The
filter assembly 10 of the subject invention incorporates at least
one retention post 26, as shown in FIG. 4, that extends through the
inner cavity 24 and between the first and second ends 20, 22 of the
filter element 18 to maintain the axial arrangement of the wave
coils 12. The first end 20 of the filter element 18, as disclosed
throughout the Figures, is a bottom end 20 of the filter element
18, and the second end 22 of the filter element 18, as disclosed
throughout the Figures, is a top end 22 of the filter element 18.
Therefore, the subject description will continue only with
reference to the top and bottom ends 20, 22 of the filter element
18. However, the description of the first and second ends 20, 22 of
the filter element 18 is not intended to be limiting, and it is to
be understood that the first and second ends 20, 22 of the filter
element 18 could also be a left and right end of the filter element
18. Also, the diameter, the length L, and the stiffness of the
filter element 18 may vary.
[0030] As shown in the Figures, the wave coils 12 that define the
filter element 18 are preferably a wave spring. As such, the wave
coils 12 preferably extend continuously in an endless path through
the crests 14 and troughs 16 and between the first and second ends
20, 22 of the filter element 18. It is to be understood that the
wave coils 12 are not required to extend continuously. That is,
although not preferred, the subject invention may include
connecting members, not shown in the Figures, that connect each of
the wave coils 12 together. In this embodiment, the wave coils 12
can be said to be segmented. Also, in the preferred embodiment, the
wave coils 12 actually extend continuously in a helix through the
endless path between the first and second ends 20, 22.
[0031] Referring now to FIGS. 3A through 3C, the wave coils 12
include a shearing surface 28. The shearing surface 28 imparts
shear forces on the fluid as the fluid is being filtered.
Preferably, the shearing surfaces 28 of the wave coils 12 include a
plurality of ridges 30 to enhance the shear forces imparted on the
fluid being filtered. As shown in FIGS. 3A through 3C, the ridges
30 may be of varying shapes and sizes depending on the purpose for
the filter assembly 10. For instance, if shearing of the fluid is
the primary purpose, then the ridges 30 having sharp, cone-shaped
teeth, as shown in FIG. 3C are ideal. Preferably, the ridges 30 are
laser-etched both transversely and sequentially along the wave
coils 12, and the ridges 30 are machined to ridge depths on the
wave coils 12 of from hundredths of millimicrons to microns.
Alternatively, the ridges 30 may be photo-etched.
[0032] It is not required that the wave coils 12 be only flat or
ridged for shearing purposes. That is, although not preferred, the
wave coils 12 may even be formed from round or smooth stock.
Furthermore, the wave coils 12 may include a coating for modifying
the flow of the fluid being filtered. That is, the wave coils 12
may be coated to adsorb or to repel solutes in the fluid. Such
coatings include, but are not limited to, magnetic coatings,
hydrophilic coatings, hydrophobic coatings, and specific affinity
coatings such as antibodies which have a specific affinity toward a
particular antigen such as PCBs. The coatings can assist the wave
coils 12 in performing `micro-filtration` when the filtration
apertures are at a 0 micron filtration aperture 34 size, which is
described below. The hydrophobic coating is particularly useful
throughout industrial applications for the filtering of water, oil,
and water/oil mixtures.
[0033] The filter assembly 10 also includes a support 32 that
engages one of the bottom and top ends 20, 22 of the filter element
18 for supporting the wave coils 12. That is, the support 32
engages either the bottom end 20 or top end 22. The support 32 also
diverts the fluid inside or outside of the inner cavity 24 of the
filter element 18. In other words, the support 32 also diverts the
fluid to one of the inside and outside of the inner cavity 24.
Depending on the embodiment, the support 32 functions to divert the
fluid inside the inner cavity 24 or to divert the fluid outside the
inner cavity 24. The support 32 will be described in further detail
below.
[0034] The crests 14 of one wave coil 12 engage the trough 16 of an
adjacent wave coil 12 to define at least one filtration aperture
34, or a filtration pore, between each crest 14 and each trough 16
of the adjacent wave coils 12. Preferably the filtration aperture
34 is spindle-shaped as disclosed throughout the Figures. In a
preferred embodiment, the filter element 18 is 2.25 inches in
diameter, the length L is 5 inches, the filter element 18 includes
100 wave coils 12, and each wave coil 12 engages the adjacent wave
coil 12 three and one-half times per 360.degree.. Of course, the
number of times each wave coil 12 engages the adjacent wave coil 12
can vary. It is to be understood that, with the exception of FIG.
1A, the crests 14 and troughs 16, as well as the at least one
filtration aperture 34 defined therebetween, are significantly
exaggerated for the descriptive and illustrative purposes of
subject invention. As disclosed throughout the Figures, the subject
invention preferably includes a plurality of filtration apertures
34, and the subject invention will be described below in terms of
the plurality of filtration apertures 34 although more than one
filtration aperture 34 is not necessarily required.
[0035] The fluid that is diverted by the support 32 is filtered
through the filtration apertures 34. This will be described below.
For now, if, for example, the filtration apertures 34 had a crest
14-to-trough 16 separation of 500 microns, then any particulates
suspended within the fluid that are less than 500 microns will pass
through the filtration apertures 34 as a filtrate 36 of the fluid,
and any particulates suspended within the fluid that are greater or
equal to 500 microns will be retained on the filter element 18 as a
retentate 38, or filter cake, of the fluid.
[0036] Referring primarily to FIGS. 4 through 7, the filter
assembly 10 of the subject invention further includes an adjustment
mechanism 40. More specifically, the adjustment mechanism 40
engages at least one of the bottom and top ends 20, 22 of the
filter element 18 for modifying the length L, extending between the
first and second ends 20, 22 of the filter element 18, to reduce
and expand the at least one filtration aperture 34 or the
filtration apertures 34. Therefore, the filtration apertures 34 are
variably-size filtration aperture 34 because they are adjustable or
tunable by the adjustment mechanism 40. The filtration apertures 34
are adjustable, depending on process requirements and the
characteristics of the filter element 18, specifically of the wave
coils 12, between a maximum filtration aperture 34 size and a 0
micron filtration aperture 34 size. The length L is increased to
expand the at least one filtration aperture 34, or to allow the
crests 14 and troughs 16 to decompress, and the length L is
decreased to reduce the at least one filtration aperture 34, or to
compress the crests 14 and troughs 16. Although the adjustment
mechanism 40 varies depending on the embodiment, the adjustment
mechanism 40 is preferably at least partially disposed in the inner
cavity 24 of the filter element 18.
[0037] The adjustment mechanism 40 includes a base plate 42
engaging one of the bottom and top ends 20, 22 of the filter
element 18. As shown in FIG. 4, the base plate 42 preferably
engages the bottom end 20 of the filter element 18. The support 32,
introduced above, is further defined as the base plate 42. As such,
the base plate 42 supports the wave coils 12 and also diverts the
fluid inside or outside of the inner cavity 24 for filtering. As
understood by those skilled in the art, in the embodiment where the
fluid is first diverted inside of the inner cavity 24, as shown in
FIG. 10A, the base plate 42 is preferably a doughnut-shaped plate
surrounding the filter element 18 that blocks the outside of the
inner cavity 24 such that the fluid can only flow into the inside
of the inner cavity 24.
[0038] The base plate 42 includes a base collar 44 and a platform
46 extending from the collar 44. The platform 46 of the base plate
42 is at least partially disposed in the inner cavity 24 of the
filter element 18. In this position, the platform 46 operates to
keep the base plate 42 in engagement with either the bottom end 20
or top end 22 of the filter element 18. The wave coils 12 of the
filter element 18 are preferably anchored to the platform 46. A
shoulder portion 48 of the base plate 42 is defined between the
base collar 44 and the platform 46. The shoulder portion 48 of the
base plate 42 actually supports one of the bottom and top ends 20,
22 of the filter element 18. As shown in FIGS. 4 and 5A, the
shoulder portion 48 supports the bottom end 20 of the filter
element 18.
[0039] In the preferred embodiment, the adjustment mechanism 40
further includes a flange member 50 that engages the other of the
bottom and top ends 20, 22 of the filter element 18 relative to the
base plate 42. The flange member 50, as described in greater detail
below, is adjustably engage relative to the base plate 42 for
modifying the length L. As such the filtration apertures 34 can be
reduced and expanded.
[0040] The flange member 50 more specifically includes a flange
collar 52 and a yoke 54. The yoke 54 extends from the collar 52
toward the base plate 42. Preferably, the yoke 54 is integrally
molded with the flange collar 52 and includes a yoke base segment
56 that is described below. The yoke 54 of the flange member 50 is
at least partially disposed in the inner cavity 24 of the filter
element 18 to keep the flange member 50 in engagement with the
other of the bottom and top ends 20, 22 of the filter element 18
relative to the base plate 42. That is, the yoke 54 keeps the
flange member 50 in engagement with the top end 22 of the filter
element 18. A shoulder portion 58 of the flange member 50 is
defined between the flange collar 52 and the yoke 54. The shoulder
portion 58 of the flange member 50 supports the other of the bottom
and top ends 20, 22 of the filter element 18 relative to the base
plate 42. That is, the shoulder portion 58 of the flange member 50
supports the top end 22 of the filter element 18.
[0041] The adjustment mechanism 40 more specifically includes at
least one pilot spring 60, preferably a compression spring. As will
be described below, the pilot spring 60 subjects the filter
assembly 10 to a loading pressure by biasing the flange member 50.
The pilot spring 60 is supported on the yoke 54 of the flange
member 50. More specifically, the pilot spring 60 is supported on
the base segment 56 of the yoke 54 and is further supported by
first and second washers 61, 63. The base segment 56 of the yoke 54
defines an opening, not numbered, and the pilot spring 60 is
supported on the base segment 56 of the yoke 54 about the opening.
In this position, the pilot spring 60 biases the flange member 50
to decrease the length L of the filter element 18 and reduce the
filtration apertures 34, and the pilot spring 60 biases the flange
member 50 to increase the length L of the filter element 18 and
expand the filtration apertures 34.
[0042] The adjustment mechanism 40 of the filter assembly 10
further includes an adjustment shaft 62. As disclosed throughout
the Figures, the adjustment shaft 62 extends from the base plate 42
to engage the flange member 50 such that the flange member 50 is
adjustable relative to the base plate 42. More specifically, the
adjustment shaft 62 extends from the base plate 42 through the
opening and the pilot spring 60 to engage the flange member 50 such
that the flange member 50 is adjustable relative to the base plate
42. As such, the length L of the filter element 18, as described
above, can be modified. Preferably, the adjustment shaft 62 extends
from the base plate 42 though the inner cavity 24 of the filter
element 18 to engage the flange member 50. Also in the preferred
embodiment, the adjustment shaft 62 is threaded and is integrally
molded with the base plate 42. It is to be understood that the
adjustment shaft 62 may alternatively include locking teeth or
detents, as opposed to threads. In certain embodiments of the
subject invention, the adjustment shaft 62 can be rendered
electromagnetic such that the wave coils 12 are
magnetically-induced by the adjustment shaft 62 to adsorb a fluid
having magnetic particles. This electro-magnetized adjustment shaft
62 is preferably used throughout various medical applications
including, but not limited to, blood separation applications where
cellular and viral components are removed from blood using magnetic
antibodies.
[0043] To make the flange member 50 adjustable relative to the base
plate 42, the subject invention includes an adjustable lock 64 that
engages the adjustment shaft 62. More specifically, the adjustable
lock 64 is disposed on the adjustment shaft 62, adjacent the spring
60 and opposite the base segment 56 of the flange member 50, for
adjusting the flange member 50 relative to the base plate 42 to
modify the length L. Manipulation of the adjustable lock 64
directly causes the spring 60 to bias the flange member 50. In the
preferred embodiment, the adjustable lock 64 is a threaded
adjustment nut 66 that is disposed on the threaded adjustment shaft
62. In alternative embodiments, the adjustable lock 64 may be
designed to engage and lock locking teeth or detents on the
adjustment shaft 62. As shown in FIG. 4, a set screw 68 may extend
through the adjustable lock 64 to the adjustment shaft 62 to ensure
that the adjustable lock 64 is locked on the adjustment shaft 62
for retaining the flange member 50 in an adjusted position relative
to the base plate 42.
[0044] When operating the adjustable lock 64 to reduce the
filtration apertures 34, the lock is tightened on the adjustment
shaft 62. The pilot spring 60 exerts a compressive force on the
flange member 50 which, in turn, exerts a compressive force on the
filter element 18. As understood by those skilled in the art, the
strength of the pilot spring 60, i.e., the weight required to
compress the pilot spring 60, must exceed the strength of the wave
coils 12, i.e., the weight required to compress the wave coils 12,
that define the filter element 18. For example, the strength of the
pilot spring 60 could be 32 pounds and the strength of the wave
coils 12 could be 25 pounds. In such an example, when the
adjustable lock 64 is tightened, pressure is applied to the
stronger pilot spring 60 which transfers the compressive pressure
to the weaker wave coils 12 of the filter element 18 thereby
reducing the filtration apertures 34. The opposite occurs when the
adjustable lock 64 is loosened on the adjustment shaft 62. The
reduction and expansion of the filtration apertures 34 may be
calibrated by developing a linear plot of the rotations of the
adjustable lock 64 versus the size of the filtration apertures
34.
[0045] In alternative embodiments of the subject invention,
disclosed in FIGS. 6A, 6B, and 7, the adjustment mechanism 40
varies. Referring now to FIG. 6A, the flange member 50 only
includes a flange collar 52, i.e., the yoke 54 is not a functioning
component of the flange member 50. Instead, the flange collar 52
acts as a fixed plate, not numbered, engaging the other of the
bottom and top ends 20, 22 of the filter element 18 relative to the
base plate 42. That is, in this embodiment, the fixed plate engages
the top end 22 of the filter element 18. In this embodiment, the
flange member 50 also includes a sliding plate 70, also known as a
floating plate. As described in the orientation disclosed in FIG.
6A, the sliding plate 70 is disposed between the base plate 42 and
the fixed plate. The base plate 42 is adjustable. More
specifically, the sliding plate 70 is supported above the base
plate 42 by one or more pilot springs 60. The sliding plate 70 is
adjustably engaged relative to the fixed plate for modifying the
length L of the filter element 18 to reduce and expand the
filtration apertures 34. Preferably, the sliding plate 70 is
adjustable relative to the fixed plate along side posts 71 which
may, or may not be, the same as the retention posts 26. Preferably,
a controller 72, as shown in FIG. 9, is in communication with the
sliding plate 70 of this alternative adjustment mechanism 40 to
automatically adjust the sliding plate 70 relative to the fixed
plate. Other functions of the controller 72 will be described
below.
[0046] In contrast to automatic adjustment accomplished, in part,
with the controller 72, a manual adjustment assembly 74, shown
generally in FIG. 6A and more specifically in FIG. 6B, may be used
to modify the length L of the filter element 18. More specifically,
the manual adjustment assembly 74. The assembly 74 includes an
adjustment handle 76. The adjustment handle 76 rotates a handle
adjustment nut 78, preferably a packing nut. The adjustment handle
76, through rotation of the handle adjustment nut 78, contacts a
packing spring 80 to advance or pull-back a drive rod 82. As shown
in the Figures, the drive rod 82 is in direct contact with the base
plate 42 and is in indirect contact with the sliding plate 70 via
the pilot springs 60. Of course, it is to be understood that a
number of turns of the adjustment handle 76 can be correlated to
the size of the filtration apertures 34.
[0047] Referring now to FIG. 7, the subject invention includes a
motor 84, selectively activated by the controller 72, refer to FIG.
9, to automatically adjust the adjustment mechanism 40. It is to be
understood that the motor 84 can be selectively activated by the
controller 72 in response to various forms of data including, but
not limited to, flow data, pressure data, solids loading data, time
data, and particle size distribution data. In the alternative
embodiment for the adjustment mechanism 40 disclosed in FIG. 7, the
sliding plate 70 is eliminated as well as the pilot springs 60.
Instead, the drive rod 82 of the adjustment mechanism 40 is rigidly
fixed, as through a weld or screw end, directly to the base plate
42 that supports the filter element 18. The base plate 42 is
adjustable. In this embodiment, referred to as `direct drive,` the
motor 82 preferably has two settings, a maximum setting for
controlling the size of the filtration apertures 34 during
filtering, and a minimum setting for expanding the filtration
apertures 34 during automatic backwashing, which is described
below. Of course, in either of the embodiments disclosed in FIGS.
6A and 7, the manual adjustment assembly 74 and the motor for
automatically adjusting the adjustment mechanism 40 can be
interchanged.
[0048] The filter assembly 10 of the subject invention is utilized
in combination with a filter canister 86. The filter canister 86
includes an inlet 88 for receiving the fluid to be filtered and an
outlet 90 for delivering the fluid that has been filtered. As shown
in FIG. 5A, the inlet 88 of the filter canister 86 is preferably
oval-shaped to impart a vortex onto the fluid received into the
filter canister 86 for filtering. The vortex imparted by the
oval-shaped inlet 88 is effective in exposing the fluid to the
filter element 18. The vortex also maintains the retentate 38
toward an inner wall 92 of the filter canister 86 and away from the
filtration apertures 34 as long as possible. The canister 86 may
also include internal blades, baffles, and the like to encourage a
vortex and more effectively expose the fluid to the filter element
18.
[0049] The filter assembly 10, and in particular the filter element
18 of the filter assembly 10, is disposed in the filter canister
86. More specifically, the filter canister 86 includes a shelf 94
for supporting the filter assembly 10 in the filter canister 86. A
gasket 96, such as an O-ring, is disposed about the flange member
50 to mate with the shelf 94 of the filter canister 86. As such,
the outlet 90 of the filter canister 86 is sealed from the inlet 88
of the filter canister 86. More specifically, the flange collar 52
of the flange member 50 includes a machined depression 98. The
gasket 96 is disposed in the machined depression 98 to ensure that
the filter assembly 10 fits tightly into the shelf 94 of the filter
canister 86. The gasket 96 presses against the inner wall 92 of the
filter canister 86 such that outlet 90 of the filter canister 86 is
sealed from the inlet 88 of the filter canister 86. Furthermore, a
plurality of fastening screws 100 extend through the flange collar
52 and into threaded inserts 102 in the shelf 94 of the filter
canister 86. Once the filter element 18 and flange member 50,
including the flange collar 52, are inserted into the filter
canister 86, the fastening screws 100 are tightened to rigidly
maintain the filter assembly 10 on the shelf 94. Rigid maintenance
of the filter assembly 10 on the shelf 94 ensures that the outlet
90 and inlet 88 of the filter canister 86 are sealed, resists
movement of the filter assembly 10 during activation of the
adjustment mechanism 40 to modify the length L, and resists
movement of the filter assembly 10 during automatic backwashing of
the filter assembly 10, which is described below.
[0050] Referring now to FIGS. 8A, 8B, and 9, the subject invention
preferably incorporates a plurality of the filter assemblies 10.
The plurality of filter assemblies 10 are disclosed in a nested
configuration in FIGS. 8A and 8B. That is, at least one filter
assembly 10 included in the plurality of filter assemblies 10 is
disposed concentrically about another filter assembly 10 of the
plurality. In this nested configuration, a coarse filter assembly
10A is disposed within a fine filter assembly 10B. Of course, it is
to be understood that any number of filter assemblies 10 may be
nested with each other.
[0051] This embodiment also includes baffle cages 104 that support
at least one baffle 106. The baffle cages 104, supporting the
baffles 106, are disposed within the inner cavity 24 of the filter
element 18 of a particular filter assembly 10. The baffles 106
provide structural support to the filter elements 18 and are
preferably angled so as to direct the fluid that is being filtered
toward the filtration apertures 34. As shown in FIG. 8B, the
baffles 106 are preferably hollow such that a filtration additive
can be delivered to the filtration apertures 34 through the baffles
106. One suitable filtration additive, steam, enhances the
filtering, or other stripping, of the fluid that is being filtered.
Other suitable filtration additives include oxygen for
bioprocessing capabilities. Additionally, a plurality of beads 108
may be disposed within the inner cavities 24 of the filter elements
18 for increasing a surface area of the fluid that is exposed for
filtering. The beads 108 are preferably used in combination with
baffles 106 that are hollow because the beads 108 are particularly
effective in exposing the fluid to be filtered to the filtration
additive.
[0052] As shown in FIG. 9, the filter assemblies 10 can be arranged
in parallel P and/or in series S depending on various process
requirements. The plurality of filter assemblies 10 can also be
arranged in a pyramid sequence. The purpose of the pyramid sequence
is to utilize more than one filter assembly 10 having different
filtration aperture 34 sizes to segregate coarse solid particles
from intermediate and fine solid particles where the filtration
apertures 34 would otherwise become immediately `blinded.` The
pyramid sequence is represented in FIG. 9 by the filtration
aperture 34 sizes of 125 microns, 50 microns, and 25 microns. Of
course, it is to be understood that such a pyramid sequence may be
continuously altered to accommodate suspended particle size
distribution and also to equalize flow rates across the filter
assemblies 10.
[0053] As shown schematically in FIG. 9, the controller 72 is in
communication with the filter assemblies 10, in particular with the
adjustment mechanisms 40 of each filter assembly 10. The controller
72 is also in communication with pressure 110, temperature 112, and
flow sensors 114, and with the valves, shown schematically, in FIG.
9. The adjustment mechanism 40 can automatically modify the length
L of the filter element 18 to automatically reduce and expand the
filtration apertures 34 as needed. The automatic modification of
the length L is primarily facilitated by at least one pressure
sensor 110 that is in communication with the controller 72. The
pressure sensor 110 communicates with the controller 72, and the
controller 72 activates the adjustment mechanism 40, preferably
through the motor 84, to automatically reduce and expand the
filtration apertures 34.
[0054] As shown in FIGS. 5A, 5B, 6A, 7, and 9, an inlet valve 116
is disposed at the inlet 88 of the filter canister 86 and an outlet
valve 118 is disposed at the outlet 90 of the filter canister 86.
The outlet valve 118 will be described further below. The inlet
valve 116 isolates the filter canister 86 from the fluid to be
filtered when necessary such as upon automatic backwashing as
described below. The controller 72 is in communication with the
inlet valve 116 to open and close the valve 116 and accomplish this
isolation. Referring to FIGS. 5A and 5B, the inlet valve 116 is
preferably a three-way inlet valve 116. In a filtering position of
the three-way inlet valve 116, as disclosed in FIG. 5A, the inlet
valve 116 allows the fluid that is to be filtered to flow through
the valve 116 and into the inlet 88 of the filter canister 86 for
filtering. However, in a backwash position 120 of the three-way
inlet valve, as disclosed in FIG. 5B, the inlet valve 116 isolates
the filter canister 86 from the fluid to be filtered. Instead, as
will be described below, the retentate 38 of the fluid is able to
flow through the inlet valve 116 when the inlet valve 116 is in the
backwash position 120.
[0055] Preferably, there is a first pressure sensor 122 disposed at
the inlet 88 of the filter canister 86 and a second pressure sensor
124 disposed at the outlet 90 of the filter canister 86. The first
pressure sensor 122 determines an inlet pressure and the second
pressure sensor 124 determines an outlet pressure. The fist and
second pressure sensors 122, 124 are in communication with the
controller 72. A difference between the inlet pressure and the
outlet pressure, which can be determined by the controller 72,
establishes a pressure differential. In reliance on this pressure
differential, the controller 72 can activate the inlet valve 116 to
isolate the filter canister 86 from the fluid to be filtered. More
specifically, the controller 72 can activate the inlet valve 116 to
isolate the filter canister 86 when the outlet pressure is less
than the inlet pressure by a predetermined amount.
[0056] The method of filtering the fluid according to the subject
invention includes the step of flowing the fluid toward the support
32 of the filter assembly 10. In the context of the preferred
embodiment, the fluid flows toward the base plate 42 of the
adjustment mechanism 40 operating as the support 32. The base plate
42 diverts the fluid inside or outside the inner cavity 24 of the
filter element 18. Once inside or outside the inner cavity 24, the
diverted fluid is filtered through the filtration apertures 34
defined between the crests 14 and the troughs 16. As such, the
filtrate 36 of the fluid passes through one of the inside or
outside of the inner cavity 24 and the retentate 38 of the fluid is
retained on the other of the inside or outside of the inner cavity
24 relative to the filtrate 36. That is, the filtrate 36 passes
through either the inside or outside of the inner cavity 24 and the
retentate 38 is retained on the opposite side of the inner cavity
24 of the filter element 18 relative to the filtrate 36.
[0057] Referring now to FIG. 10A, if the fluid flows toward the
base plate 42 and is diverted to the inside of the inner cavity 24
and then through the filtration apertures 34, then the filtrate 36
of the fluid, which also flows through the filtration apertures 34,
passes through the outside of the inner cavity 24 to the outlet 90
of the filter canister 86, and the retentate 38 of the fluid, which
cannot flow through the filtration apertures 34, is retained on the
inside of the inner cavity 24 of the filter element 18. As
described above, in this embodiment, the base plate 42 is
preferably the doughnut-shaped plate surrounding the filter element
18 that blocks the outside of the inner cavity 24 such that the
fluid can only flow into the inside of the inner cavity 24.
Alternatively, as shown in FIG. 10B, if the fluid flows toward the
base plate 42 and is diverted to the outside of the inner cavity 24
and then through the filtration apertures 34, then the filtrate 36
of the fluid flows through the filtration apertures 34 and passes
through the inside of the inner cavity 24 to the outlet 90 of the
filter canister 86, whereas the retentate 38 of the fluid is
retained on the outside of the inner cavity 24 of the filter
element 18.
[0058] The method of filtering utilizing the filter assembly 10
according to the subject invention also includes the step of
adjusting the filter assembly 10 to reduce and expand the
filtration apertures 34. It is to be understood that the step of
adjusting the filter assembly 10 is preferably accomplished with
the adjustment mechanism 40 in communication with the pressure
sensor or sensors 110, 122, 124 and the controller 72 as described
above.
[0059] The method further includes the step of cleaning the filter
assembly 10. The most preferred manner in which to clean the filter
assembly 10 is by automatically backwashing the filter assembly 10
by momentarily reversing the flow of the filtrate 36, or another
fluid, as described immediately below. To automatically backwash
the filter assembly 10, the filter assembly 10 is isolated from the
fluid to be filtered. To isolate the filter assembly 10 from the
fluid to be filtered, the inlet valve 116 at the inlet 88 of the
filter canister 86 is closed. In the preferred embodiment, the
inlet valve 116 is activated into the backwash position 120. Once
the filter assembly 10 is isolated from the fluid to be filtered,
the filtrating apertures 34 are expanded. The filtration apertures
34 may be expanded at regularly-defined time intervals or according
to other process parameters as described above. However, the
filtration apertures 34 are preferably automatically expanded in
response to the pressure differential between the bottom and top
ends 20, 22 of the filter element 18. That is, the filtration
apertures 34 are preferably automatically expanded when the
pressure differential exceeds the predetermined amount such as when
the outlet pressure is less than the inlet pressure by the
predetermined amount. Once the filter assembly 10 is isolated, the
adjustment mechanism 40 increases the length L of the filter
element 18 to expand the filtration apertures 34. In the most
preferred embodiment, the threaded adjustment nut 66 is
automatically loosened on the threaded adjustment shaft 62 and the
length L of the filter element 18 automatically expands.
[0060] Once the filtration apertures 34 are expanded, the flow of
the fluid that has been filtered, i.e., the filtrate 36, is
reversed such that the filtrate 36 flows back through the
filtration apertures 34 and the retentate 38 of the fluid is
automatically dislodged from the inside or the outside of the inner
cavity 24, depending on the embodiment. It is also to be understood
that the flow of the filtrate 36 may be reversed at the same time,
or even before, the filtration apertures 34 are expanded. Of
course, as the retentate 38 is automatically dislodged, the
backwash position 120 of the preferred three-way inlet valve allows
the dislodged retentate 38 to flow to a retentate 38 collection
reservoir that collects the backwashed retentate 38. Once the
filter assembly 10 is clean, the flow of the filtrate 36 returns to
normal.
[0061] Alternatively, the outlet valve 118 at the outlet 90 of the
filter canister 86 may be a three-way outlet valve 118, similar to
the three-way inlet valve 116. As such, this three way outlet valve
118 can be manipulated to a position such that a second fluid,
distinct from the fluid that has been filtered, i.e., the filtrate
36, can be utilized to flow back through the filtration apertures
34 to automatically backwash the filter assembly 10 by dislodging
the retentate 38. In this situation, the filtrate 36 is not used to
automatically backwash the filter assembly 10. In this embodiment,
the three-way outlet valve 118 allows the filter canister 86 to
selectively receive fluid for back-washing the filter element 18
when the outlet pressure is less than the inlet pressure by the
predetermined amount as communicated by the controller 72.
[0062] The invention has been described in an illustrative manner,
and it is to be understood that the terminology which has been used
is intended to be in the nature of words of description rather than
of limitation. Obviously, many modifications and variations of the
present invention are possible in light of the above teachings. The
invention may be practiced otherwise than as specifically described
within the scope of the appended claims. Furthermore, the reference
numerals are merely for convenience and are not to be in any way to
be read as limiting.
* * * * *