U.S. patent application number 09/761504 was filed with the patent office on 2001-06-28 for method of fluid filtering.
Invention is credited to Gryder, Edd D., Morgan, Dennis R..
Application Number | 20010004977 09/761504 |
Document ID | / |
Family ID | 22173101 |
Filed Date | 2001-06-28 |
United States Patent
Application |
20010004977 |
Kind Code |
A1 |
Morgan, Dennis R. ; et
al. |
June 28, 2001 |
Method of fluid filtering
Abstract
The present invention typically involves the use of a compressed
blocking area to assist in sealing a filter element and avoiding
channeling in a wound fibrous tissue filtering system. It may
involve the use of multiple, spaced, interstitial rings. It may
involve the intentional wasting of a portion of the filter element
to create a compressed blocking area. It may also involve the use
of different heights of the rings and may include the use of
compression and secondary tapers on the rings. The heights and
spacing of the rings with respect to the other ring or rings may
vary in a certain ratio.
Inventors: |
Morgan, Dennis R.; (Howard,
OH) ; Gryder, Edd D.; (Evansville, WI) |
Correspondence
Address: |
Santangelo Law Offices, P.C.
Third Floor
125 South Howes
Fort Collins
CO
80521
US
|
Family ID: |
22173101 |
Appl. No.: |
09/761504 |
Filed: |
January 17, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09761504 |
Jan 17, 2001 |
|
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09082734 |
May 21, 1998 |
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Current U.S.
Class: |
210/767 ;
210/224; 210/445; 210/455; 210/808 |
Current CPC
Class: |
B01D 29/54 20130101;
B01D 29/073 20130101; B01D 2201/34 20130101 |
Class at
Publication: |
210/767 ;
210/224; 210/445; 210/455; 210/808 |
International
Class: |
B01D 037/00 |
Claims
1. A method of filtering a fluid comprising the steps of: a.
accepting a flow of unfiltered fluid into a container; b. flowing
said unfiltered fluid in an unfiltered flow path in said container;
c. blocking said flow of unfiltered fluid in a blocking area
through action on a filtering medium; d. filtering said unfiltered
fluid to produce a filtered fluid in a filtering area of said
filtering medium wherein said filtering occurs on an opposite side
of said blocking area from said unfiltered fluid; e. interposing at
least a portion of said filtering medium between said blocking area
and said unfiltered fluid; and f. allowing said filtered fluid to
pass out of said container.
2. A method of filtering a fluid as described in claim 1 wherein
said step of blocking said flow comprises the step of blocking said
flow with a compressive force on said blocking area that is greater
than a hydraulic flow force.
3. A method of filtering a fluid as described in claim 2 wherein
said step of blocking said flow with a compressive force further
comprises the step of blocking said flow with a radial compressive
force.
4. A method of filtering a fluid as described in claim 1 wherein
said step of blocking said flow comprises the step of annularly
uniformly compressing said blocking area.
5. A method of filtering a fluid as described in claim 1 wherein
said step of blocking said flow comprises the step of continuously
compressing said blocking area.
6. A method of filtering a fluid as described in claim 1 wherein
said step of blocking said flow comprises the step of step-wise
compressing said blocking area.
7. A method of filtering a fluid as described in claim 1 wherein
said step of blocking said flow comprises the step of non-linearly
compressing said blocking area.
8. A method of filtering a fluid as described in claim 1 wherein
said step of blocking said flow comprises the step of parabolically
compressing said blocking area.
9. A method of filtering a fluid as described in claim 1 wherein
said step of blocking said flow comprises the step compressing a
thickness of said blocking area of approximately one quarter
inch.
10. A method of filtering a fluid as described in claim 1 wherein
said step of blocking said flow comprises the step of blocking
through the use of interstitial rings.
11. A method of filtering a fluid as described in claim 10 further
comprising the step of blocking through a blocking area having a
height to thickness ratio of approximately 100%.
12. A method of filtering a fluid as described in claim 1 wherein
said step of blocking comprises the step of utilizing a plurality
of rings and further comprises the step of engaging at different
heights said plurality of rings to establish said blocking
area.
13. A method of filtering a fluid as described in claim 12 wherein
said step of utilizing a plurality of rings comprises the step of
utilizing a first ring and a second ring and further comprises the
step of engaging said first ring before engaging second ring to
establish said blocking area.
14. A method of filtering a fluid as described in claim 13 further
comprising the steps of: a. engaging a secondary taper on said
first ring; then b. engaging a secondary taper on said second ring;
and then c. engaging a compression taper on said first ring.
15. A method of filtering a fluid as described in claim 13 further
comprising the steps of: a. engaging a secondary taper on said
first ring; then b. engaging a compression taper on said first
ring; and then c. engaging a secondary taper on said second
ring.
16. A method of filtering a fluid as described in claim 13 further
comprising the steps of: a. engaging a secondary taper on said
first ring; then b. engaging a secondary taper on said second ring;
and then c. engaging a compression taper on said second ring.
17. A method of filtering a fluid comprising the steps of: a.
accepting a flow of unfiltered fluid into a container; b. flowing
said unfiltered fluid in an unfiltered flow path in said container;
c. blocking said flow of unfiltered fluid in a blocking area
through action of a filtering medium; d. filtering said unfiltered
fluid to produce a filtered fluid in a filtering area of said
filtering medium wherein said filtering occurs on an opposite side
of said blocking area from said unfiltered fluid; e. interposing at
least a portion of said filtering medium between said blocking area
and said unfiltered fluid; and f. allowing said filtered fluid to
pass out of said container.
18. A pressurized axial flow fluid filter comprising: a. a fluid
holding container with an inlet and an outlet; b. a filter element
fluidicly connected to said container comprising a filtering medium
to filter an unfiltered fluid; c. a filtered flow path in said
filter element; d. a blocking area to separate said filtered flow
path from said unfiltered fluid in said container; and e. an
interposed portion of said filtering medium between said blocking
area and said unfiltered fluid.
19. A pressurized axial flow fluid filter as described in claim 18
wherein said blocking area is interactively established by a first
and second ring.
20. A pressurized axial flow fluid filter as described in claim 18
wherein said blocking area comprises a discrete annular area within
said filter element wherein a ring compression force formed by an
interaction of said first ring and said second ring on said
blocking area is greater than a hydraulic flow force on said filter
element.
21. A pressurized axial flow fluid filter as described in claim 18
wherein said blocking area comprises an annularly uniform
compressed blocking area.
22. A pressurized axial flow fluid filter as described in claim 18
wherein said blocking area comprises a continuously compressed
blocking area.
23. A pressurized axial flow fluid filter as described in claim 18
wherein said blocking area comprises a step-wise compressed
blocking area.
24. A pressurized axial flow fluid filter as described in claim 18
wherein said blocking area comprises a non-linearly compressed
blocking area.
25. A pressurized axial flow fluid filter as described in claim 18
wherein said blocking area comprises a parabolically compressed
blocking area.
26. A pressurized axial flow fluid filter as described in claim 18
wherein said blocking area is approximately one quarter inch
thick.
27. A pressurized axial flow fluid filter as described in claim 19
wherein said blocking area has an average ring height to thickness
ration of approximately 100%.
28. A pressurized axial flow fluid filter as described in claim 19
wherein said first and second rings have different heights.
29. A pressurized axial flow fluid filter as described in claim 18
wherein said first ring has a secondary taper higher than a
secondary taper on said second ring and wherein said secondary
taper on said second ring is higher than a compression taper on
said first ring.
30. A pressurized axial flow fluid filter as described in claim 18
wherein said first ring has a secondary taper higher than a
secondary taper on said second ring and wherein a compression taper
on said first ring is higher than said secondary taper on said
second ring.
31. A pressurized axial flow fluid filter as described in claim 18
wherein said first ring has a secondary taper higher than a
secondary taper on said second ring and wherein a compression taper
on said second ring is higher than a compression taper on said
first ring.
32. A pressurized axial flow fluid filter as described in claim 29,
30, or 31 wherein said secondary and compression tapers on said
first ring face said second ring.
33. A pressurized axial flow fluid filter as described in claim 28
wherein said first ring comprises an outer ring.
34. A method of filtering a fluid comprising the steps of: a.
accepting a flow of unfiltered fluid into a container containing a
filtering medium; b. flowing said unfiltered fluid in an unfiltered
flow path in said container; c. engaging a first interstitial ring
to said filtering medium; c. engaging a second interstitial ring
proximate to said first interstitial ring; d. interposing at least
a portion of said filtering medium between said first and second
interstitial rings and said unfiltered fluid; e. filtering said
fluid in said filtering medium to produce a filtered fluid wherein
said filtering occurs on an opposite side of each of said first and
second interstitial rings from said unfiltered fluid; and f.
allowing said filtered fluid to pass out of said container.
35. A method of filtering a fluid as described in claim 34 further
comprising the step of establishing a blocking area between said
first interstitial ring and said second interstitial ring.
36. A method of filtering a fluid as described in claim 35 further
comprising the step of uniformly compressing said blocking
area.
37. A method of filtering a fluid as described in claim 35 further
comprising the step of continuously compressing said blocking
area.
38. A method of filtering a fluid as described in claim 35 further
comprising the step of establishing said blocking area of a
thickness of approximately one quarter inch.
39. A method of filtering a fluid as described in claim 35 wherein
said step of establishing a blocking area comprises the step of
compressing said blocking area with a compressive force that is
greater than a hydraulic flow force on said filtering medium.
40. A method of filtering a fluid as described in claim 34 wherein
said rings have different heights and further comprising the step
of engaging said filtering medium at different heights relative to
said different heights of said rings.
41. A method of filtering a fluid as described in claim 40 further
comprising the steps of: a. engaging a secondary taper on said
first interstitial ring; then b. engaging a secondary taper on said
second interstitial ring; and then c. engaging a compression taper
on said first interstitial ring.
42. A method of filtering a fluid as described in claim 40 further
comprising the steps of: a. engaging a secondary taper on said
first interstitial ring; then b. engaging a compression taper on
said first interstitial ring; and then c. engaging a secondary
taper on said second interstitial ring.
43. A method of filtering a fluid as described in claim 40 further
comprising the steps of: a. engaging a secondary taper on said
first interstitial ring; then b. engaging a secondary taper on said
second interstitial ring; and then c. engaging a compression taper
on said second interstitial ring.
44. A pressurized axial flow fluid filter comprising: a. a fluid
holding container with an inlet and an outlet; b. an unfiltered
flow path containing unfiltered fluid; c. a filter element
fluidicly connected to said container comprising a filtering medium
to filter said unfiltered fluid; d. a first interstitial ring which
interstitially engages said filtering medium; e. a second
interstitial ring which interstitially engages said filtering
medium and is proximate to said first interstitial ring.
45. A pressurized axial flow fluid filter as described in claim 44
further comprising a blocking area established between said first
interstitial ring and said second interstitial ring.
46. A pressurized axial flow fluid filter as described in claim 45
wherein said blocking area comprises a uniformly compressed
blocking area by an interaction between said first interstitial
ring and said second interstitial ring.
47. A pressurized axial flow fluid filter as described in claim 45
wherein said blocking area comprises a continuously compressed
blocking area by an interaction between said first interstitial
ring and said second interstitial ring.
48. A pressurized axial flow fluid filter as described in claim 45
wherein said blocking area is approximately one quarter inch
thick.
49. A pressurized axial flow fluid filter as described in claim 45
wherein said blocking area comprises an average ring height to
thickness ratio of approximately 100%.
50. A pressurized axial flow fluid filter as described in claim 44
wherein said rings have different heights.
51. A pressurized axial flow fluid filter as described in claim 50
wherein said first ring has a secondary taper higher than a
secondary taper on said second ring and wherein said secondary
taper on said second ring is higher than a compression taper on
said first ring.
52. A pressurized axial flow fluid filter as described in claim 50
wherein said first ring has a secondary taper higher than a
secondary taper on said second ring and wherein a compression taper
on said first ring is higher than said secondary taper on said
second ring.
53. A pressurized axial flow fluid filter as described in claim 50
wherein said first ring has a secondary taper higher than a
secondary taper on said second ring and wherein a compression taper
on said second ring is higher than a compression taper on said
first ring.
54. A pressurized axial flow fluid filter as described in claim 51,
52, or 53 wherein said secondary and compression tapers on said
first ring face said second ring.
55. A pressurized axial flow fluid filter as described in claim 54
wherein said first ring comprises an outer ring.
56. A method of filtering a fluid comprising the steps of: a.
accepting a flow of unfiltered fluid into a container; b. flowing
said unfiltered fluid in an unfiltered flow path in said container
and into a filtering medium; c. assuring the annular engagement of
a uniform area of said filtering medium in a uniform engaged area;
d. filtering said unfiltered fluid in said filtering medium to
produce a filtered fluid wherein said filtering occurs on an
opposite side of said uniform engaged area from said unfiltered
fluid; and e. allowing said filtered fluid to pass out of said
container.
57. A method of filtering a fluid as described in claim 56 wherein
said step of assuring said annular engagement of said uniform area
of said filtering medium further comprises the step of annularly
uniformly blocking in said uniform engaged area.
58. A method of filtering a fluid as described in claim 57 wherein
said step of annularly uniformly blocking comprises the step of
blocking for an thickness of approximately one quarter inch.
59. A method of filtering a fluid as described in claim 57 wherein
said step of annularly uniformly blocking comprises the step of
blocking with a radial compression force that is greater than a
hydraulic flow force acting on said filtering medium.
60. A method of filtering a fluid as described in claim 56 wherein
said step of assuring said annular engagement of said uniform area
comprises the step of utilizing at least a first and second
ring.
61. A method of filtering a fluid as described in claim 60 wherein
said rings have different heights and further comprising the step
of engaging said filtering medium at different heights relative to
said different heights of said rings.
62. A method of filtering a fluid as described in claim 61 further
comprising the steps of: a. engaging a secondary taper on said
first interstitial ring; then b. engaging a secondary taper on said
second interstitial ring; and then c. engaging a compression taper
on said first interstitial ring.
63. A method of filtering a fluid as described in claim 61 further
comprising the steps of: a. engaging a secondary taper on said
first interstitial ring; then b. engaging a compression taper on
said first interstitial ring; and then c. engaging a secondary
taper on said second interstitial ring.
64. A method of filtering a fluid as described in claim 61 further
comprising the steps of: a. engaging a secondary taper on said
first interstitial ring; then b. engaging a secondary taper on said
second interstitial ring; and then c. engaging a compression taper
on said second interstitial ring.
65. A pressurized axial flow fluid filter comprising: a. a fluid
holding container into which an unfiltered fluid flows in a flow
path wherein said container comprises an inlet and an outlet; b. a
filter element fluidicly connected to said container comprising a
filtering medium; c. an uniform engaged area comprising an assured
annular engagement of a uniform portion of said filtering medium;
and d. a filtering area located on an opposite side of said uniform
engaged area from said unfiltered fluid wherein said filtering area
filters said unfiltered fluid to produce a filtered fluid which
exits said container through said outlet.
66. A pressurized axial flow fluid filter as described in claim 65
wherein said uniform engaged area comprises a blocking area.
67. A pressurized axial flow fluid filter as described in claim 66
wherein said blocking area comprises a uniformly compressed
blocking area.
68. A pressurized axial flow fluid filter as described in claim 66
wherein a radial compressive force acting on said blocking area is
greater than a hydraulic flow force acting on said filtering
medium.
69. A pressurized axial flow fluid filter as described in claim 66
wherein said blocking area is approximately one quarter inch
thick.
70. A pressurized axial flow fluid filter as described in claim 66
wherein said blocking area is created by an interaction of a first
ring and a second ring.
71. A pressurized axial flow fluid filter as described in claim 70
wherein said blocking area has a average ring height to thickness
ratio of approximately 100%.
72. A pressurized axial flow fluid filter as described in claim 70
wherein said rings have different heights.
73. A pressurized axial flow fluid filter as described in claim 72
wherein said first ring has a secondary taper higher than a
secondary taper on said second ring and wherein said secondary
taper on said second ring is higher than a compression taper on
said first ring.
74. A pressurized axial flow fluid filter as described in claim 72
wherein said first ring has a secondary taper higher than a
secondary taper on said second ring and wherein a compression taper
on said first ring is higher than said secondary taper on said
second ring.
75. A pressurized axial flow fluid filter as described in claim 72
wherein said first ring has a secondary taper higher than a
secondary taper on said second ring and wherein a compression taper
on said second ring is higher than a compression taper on said
first ring.
76. A pressurized axial flow fluid filter as described in claim 73,
74, or 75 wherein said secondary and compression tapers on said
first ring face said second ring.
77. A pressurized axial flow fluid filter as described in claim 76
wherein said first ring comprises an outer ring.
78. A method of filtering a fluid comprising the steps of: a.
accepting a flow of unfiltered fluid into a container; b. flowing
said unfiltered fluid in an unfiltered flow path in said container;
c. engaging a filtering medium with a first interstitial ring
having a first axial height and located in said container; d.
engaging said filtering medium with a second interstitial ring
having a second axial height which is different from said first
axial height; e. filtering said unfiltered fluid in said filtering
medium to produce a filtered fluid; and f. allowing said filtered
fluid to pass out of said container.
79. A method of filtering a fluid as described in claim 78 further
comprising the step of blocking said flow of unfiltered fluid in a
blocking area between said first and second interstitial ring.
80. A method of filtering a fluid as described in claim 79 further
comprising the step of interposing at least a portion of said
filtering medium between said blocking area and said unfiltered
fluid.
81. A method of filtering a fluid as described in claim 79 wherein
the step of blocking said flow comprises the step of blocking said
flow with a compressive force on said blocking area that is greater
than a hydraulic flow force.
82. A method of filtering a fluid as described in claim 79 wherein
said step of engaging said filtering medium with said first
interstitial ring occurs in the proximity of said step of engaging
said filtering medium with said second interstitial ring.
83. A method of filtering a fluid as described in claim 81 wherein
said step of blocking said flow with a compressive force further
comprises the step of blocking said flow with a radial compressive
force.
84. A method of filtering a fluid as described in claim 81 wherein
said step of blocking said flow comprises the step of annularly
uniformly compressing said blocking area.
85. A method of filtering a fluid as described in claim 78 further
comprising the steps of: a. engaging a secondary taper on said
first interstitial ring; then b. engaging a secondary taper on said
second interstitial ring; and then c. engaging a compression taper
on said first interstitial ring.
86. A method of filtering a fluid as described in claim 78 further
comprising the steps of: a. engaging a secondary taper on said
first interstitial ring; then b. engaging a compression taper on
said first interstitial ring; and then c. engaging a secondary
taper on said second interstitial ring.
87. A method of filtering a fluid as described in claim 78 further
comprising the steps of: a. engaging a secondary taper on said
first interstitial ring; then b. engaging a secondary taper on said
second interstitial ring; and then c. engaging a compression taper
on said second interstitial ring.
88. A pressurized axial flow fluid filter comprising: a. a fluid
holding container through which a fluid flows in a flow path
wherein said container comprises an inlet and an outlet; b. a
filter element fluidicly connected to said container comprising a
filtering medium to filter said fluid; c. a first interstitial ring
which engages said filtering medium and comprises a first axial
height; and d. a second interstitial ring which engages said
filtering medium and comprises a second axial height which is
different from said first axial height.
89. A pressurized axial flow fluid filter as described in claim 88
further comprising a blocking area situated between said first
interstitial ring and said second interstitial ring.
90. A pressurized axial flow fluid filter as described in claim 89
wherein said blocking area comprises a discrete annular area within
said filter element wherein a ring compression force formed by an
interaction of said first interstitial ring and said second
interstitial ring on said blocking area is greater than a hydraulic
flow force on said filter element.
91. A pressurized axial flow fluid filter as described in claim 89
wherein said blocking area comprises an annularly uniform
compressed blocking area.
92. A pressurized axial flow fluid filter as described in claim 89
wherein said blocking area comprises a continuously compressed
blocking area.
93. A pressurized axial flow fluid filter as described in claim 89
wherein said first and second axial height comprise an average ring
height and wherein said blocking area has an average ring height to
thickness ratio of approximately 100%.
94. A pressurized axial flow fluid filter as described in claim 88
wherein said first interstitial ring has a secondary taper higher
than a secondary taper on said second interstitial ring and wherein
said secondary taper on said second interstitial ring is higher
than a compression taper on said first interstitial ring.
95. A pressurized axial flow fluid filter as described in claim 88
wherein said first interstitial ring has a secondary taper higher
than a secondary taper on said second interstitial ring and wherein
a compression taper on said first interstitial ring is higher than
said secondary taper on said second interstitial ring.
96. A pressurized axial flow fluid filter as described in claim 88
wherein said first interstitial ring has a secondary taper higher
than a secondary taper on said second interstitial ring and wherein
a compression taper on said second interstitial ring is higher than
a compression taper on said first interstitial ring.
97. A pressurized axial flow fluid filter as described in claim 94,
95, or 96 wherein said secondary and compression tapers on said
first interstitial ring faces said second interstitial ring.
98. A pressurized axial flow fluid filter as described in claim 88
wherein said first interstitial ring comprises an outer ring.
99. A method of filtering a fluid comprising the steps of: a.
accepting an unfiltered fluid into a container; b. flowing said
unfiltered fluid in an unfiltered flow path in said container; c.
forcing flow through a filtering medium substantially parallel to a
filtering flow to produce a filtered fluid; d. forcing flow through
a restrictor element substantially transverse to said filtering
flow; e. blocking said flow from flowing around at least one edge
of said restrictor element; and f. allowing said filtered fluid to
pass out of said container.
100. A method of filtering a fluid as described in claim 99 further
comprising the step of creating a pressure equalization across a
cross sectional area of said substantially parallel filtering
medium with said restrictor element.
101. A method of filtering a fluid as described in claim 99 further
comprising the step of utilizing a ring located proximate to said
edge of said restrictor element to assist in said step of blocking
said flow.
102. A method of filtering a fluid as described in claim 101
further comprising the step of engaging said filtering medium
interstitially with said ring.
103. A method of filtering a fluid as described in claim 99 wherein
said step of blocking further comprises the step of blocking said
flow around an inner and an outer edge of said restrictor
element.
104. A pressurized axial flow fluid filter comprising: a. a fluid
holding container through which a fluid flows wherein said
container comprises an inlet and an outlet; b. a filtering flow
path through which said fluid is filtered; and c. a filter assembly
fluidicly connected to said filtering flow path comprising: i. a
substantially parallel filtering medium with respect to said
filtering flow path to filter said fluid; ii. a restrictor element
substantially transverse to said filtering flow path and fluidicly
connected to said substantially parallel filtering medium; and iii.
at least one lip to engage said substantially parallel filtering
medium and block said fluid flow from flowing around at least one
edge of said restrictor element.
105. A pressurized axial flow fluid filter as described in claim
104 wherein said lip comprises a curved section of said restrictor
element.
106. A pressurized axial flow fluid filter as described in claim
104 further comprising a ring located proximate to said lip wherein
said ring assists said lip to engage said substantially parallel
filtering medium and block said fluid flow.
107. A pressurized axial flow fluid filter as described in claim
104 wherein said restrictor element substantially equalizes a
pressure of said flow across a cross sectional area of said
substantially parallel filtering medium.
Description
FIELD OF INVENTION
[0001] The field of the present invention relates to fluid
filtering systems and techniques in general and to fluid filter
collector systems in particular.
BACKGROUND OF THE INVENTION
[0002] There is a maxim that four quarts of clean oil mixed with
one quart of dirty oil makes five quarts of dirty oil. In the area
of fluid filtering apparatus and related filtering applications,
this is especially true. Modem vehicles and industrial machinery
rely on a number of recirculating fluids for effective operation.
Effective filtration of these fluids can extend the life of the
apparatus and maintain the operation at high levels of performance.
Furthermore, to the extent fluids can be maintained free of
contamination, the life of the fluid itself is extended, saving
cost due to fluid replacement and machinery downtime.
[0003] One particularly effective type of fluid filter causes
fluids to flow interstitially between layers of fibrous tissue
which have been wound about an inner core. Such fluid filters may
be packaged either as disposable canisters, replaceable cartridges,
or as containers for containing generally one or more filter
elements. In-flow and out-flow connections provide the container's
inlet and outlet ports. By flowing interstitially between the
layers of filtering tissues, dirt and smudge is removed from the
fluid by the tissue layers. The fluid exits the filter element and
then is directed by a fluid collector through passageways to a flow
path which is fluidicly connected to the outlet port.
[0004] Because of the efficiency and quality of wound fibrous
tissue filtering systems, the popularity of such systems has
increased. However, this popularity has not been without a need to
improve the various sealing areas of the filtering tissue systems.
For instance, because the filtering fluid typically flows
interstitially and not transversely through the wound media, a
problem known as "channeling" can occur. Channeling typically has
the effect of short circuiting the filtering process. It may occur,
for instance, due to localized high pressures that open the space
between wound layers of fibers such that a larger portion of
unfiltered fluid may pass. Furthermore, in using these and other
types of filters, other leakages can occur. For instance, leakages
can occur around the ends of the filtering elements such that
unfiltered fluid from an unfiltered flow path leaks into a filtered
flow path and contaminates what fluid was actually filtered. Thus,
it is critical to seal the unfiltered fluid from the filtered
fluid.
[0005] Another example relates to the use of multiple filter
element in a filtering system. To increase the flow through a
filtering system, it is often desirable to provide a plurality of
stacked tissue elements to minimize flow resistance. However, the
junctions between the multiple elements is prone to leakage of
unfiltered fluid into filtered fluid. To reduce this problem, a
fluid collector is typically used.
[0006] A typical fluid collector serves to seal the end of the
filter element from leakage of unfiltered fluid to filtered fluid.
In multiple tissue element systems, it may also separate the
fibrous tissue rolls from one another and provide passage for
filtered fluid to leave the filter element. Fluid collectors,
generally known in the art, may be formed which may have a
plurality of alternating radial slots and ridges with the ridges
serving to space the fibrous tissue roll elements from the
collector and the slot serving to direct the filtered fluid into a
central flow tube. A separate fluid collector may be used or the
function of a fluid collector may be built into a container.
Typical materials include various hard plastics known to those in
the art such as Delrin 500, nylon, or other suitable materials.
[0007] A further complication of using wound fibrous layers is from
the differential pressure generated from the unfiltered flow path
to the filtered flow path. Typically, the unfiltered flow path will
have a higher pressure than the pressure of the filtered flow path
due to the pressure drop through the fluid filter. This
differential pressure may create extra stress on the fibrous layers
and overall compress the layers away from the higher pressure,
typically, toward the inner core and the filtered fluid path. These
substantial compressive forces are described in U.S. Pat. No.
4,792,397 to Rasmussen in column 1, lines 35-49 as follows:
[0008] Substantial compressive forces are exerted hydraulically on
the tissue layers. These forces tend to compress and deform the
filter elements, particularly at the end of each filter element
where the filter fluid exits into a collector. As disclosed in U.S.
Pat. No. 4,017,400 to Schade, these collectors often have an
annular portion which extends into the adjacent filter element ends
to form a seal which separates the filtered fluid from the
unfiltered fluid. Nevertheless, deformation of the filter element
at its exit end may cause flow channels to form which then allow
fluid to flow around the annular seal and thus entirely bypass the
filter element. As a result, a significant amount of unfiltered
fluid can pass around the deformed filter element without removal
of contaminants.
[0009] Obviously, in using these wound fibrous tissue filter
elements, such leakage can occur from using one or a plurality of
such filter elements in any given system. As is noted in U.S. Pat.
No. 4,773,990 to Hood in column 1, lines 24-42:
[0010] A significant problem associated with the use of axial flow
filters has been leakage of contaminated fluid around the wound
tissue filter element. Ordinarily, filter elements are positioned
on a flow tube and contaminated fluid is directed to one axial end
surface of the element where the fluid enters the tissue layers in
an axial direction, flows through the layers, and out the opposite
axial end surface of the element into an annular channel then into
the flow tube. The pressure differentials between the axial ends of
the element, and between the outer cylindrical surface of the
elements and the annular channel are typically very high,
encouraging leakage around the elements, permitting unfiltered
fluid to contaminate the filtered fluid. Numerous attempts have
been made to fashion a seal which will prevent a flow bypass of
this type.
[0011] In recognizing some of the problems, various inventors have
suggested solutions. One such solution is seen in U.S. Pat. No.
271,850 to Stutzman. In that patent, reduction of leakage bypassing
is discussed in terms of axial compression in column 5, lines
18-23:
[0012] Bypassing is precluded in the apparatus of this invention by
squeezing the filter cartridge from top and bottom between circular
stub edges to indent the cartridge faces so tightly that no fluid
can flow regularly to the axial bore or the outflow pipe without
proceeding axially through one-half of the dual cartridge.
[0013] However, other inventions realize that there is a practical
limit to how tight the actual ends can be squeezed to reduce
leakage and perhaps rely instead on other methods of sealing.
[0014] U.S. Pat. No. 4,017,400 to Schade appears to attempt to find
a solution in sealing the outer periphery of the filter element
against the container wall and providing an "interlocking annular
seal" in column 1, line 64--column 2, line 2.
[0015] An interlocking annular seal provided in the manner of this
invention is enhanced in efficiency by application of radial
pressure and will resist failure under extreme pressure better than
seals formed by axial compression of a filter element or by an
annular sealing ring which causes the filter element to be squeezed
and deformed radially.
[0016] Noteworthy, this was a single ring which apparently
attempted to restrain the filter element from pulling away from the
inner container wall surface. Unfortunately, Schade and others
apparently realized subsequent to this patent that this was not a
final solution.
[0017] While the Schade '400 reference may have recognized an issue
of radial compression, it apparently did not offer a satisfactory
solution. In U.S. Pat. No. 4,366,057 to Bridges et. al., the Schade
'400 reference is described. As a background, that reference
indicates that a "pressure drop across the filter may be in excess
of 90 P.S.I., resulting in substantial compressive forces being
exerted hydraulically on the filter tissue. These forces tend to
compress and distort the filter element, particularly at the return
or exhaust ends thereof." (Column 1, lines 33-38). Then, the
Bridges '057 reference describes that the Schade '400 reference
provided an interlocking annular seal inserted into the filter
element a few layers inwardly of the perimeter of the filter
element. The Bridges '057 reference continues in stating in Column
1, lines 45-52,
[0018] However, it has been discovered that even with such an
annular seal, the great hydraulic forces within the filter still
results in deformation of the filter element. This causes flow
channels to form which allow fluid to flow around the annular seal
and thus bypass entirely the filter element. The result is that a
significant amount of unfiltered oil is recirculated without
removal of much of the contaminates.
[0019] U.S. Pat. No. 4,773,999 to Schade, approximately eleven
years later after the Schade '400 reference, noted that "provision
of an effective seal about the outer periphery of the outflow
gallery is especially problematic because the configuration of the
wound tissue rolls tend to distort under the effects of the
differential pressure and the rolls tend to be compressed so as to
pull away from less conformable sealing means, . . . " (Column 1,
lines 19-25). The Schade '999 reference attempted to solve the
earlier problems by providing a seal "between filter elements by
wrappings of filter medium tissue being applied around the outer
peripheral surfaces of the elements to at least partially encase
such surfaces and completely overlap the space between the elements
which comprises the filtrate overflow gallery." (Column 1, lines
48-54) In other words, it appears that Schade attempted to solve
the sealing problems by providing an outer "sock" that overlaps the
gap between multiple filter elements, with the inference from the
Schade '999 reference that interstitial sealing by flow collectors
and similar devices was ineffective.
[0020] The next generation of improvements in attempting to better
seal against this type of leakage is perhaps found is U.S. Pat. No.
4,780,204 to Rasmussen assigned to Harvard Corporation of
Evansville, Wis. Among other things in that reference, the concept
of placing an annular ring portion inwardly a few tissue layers was
extended to allow a taper to a sharp edge to more easily push the
fluid collector between the layers of filtered tissue of adjacent
filter element ends without damaging the tissue. (Column 5, lines
27-32) However, even with this improvement, some additional
improvement was needed.
[0021] Another improvement is seen in U.S. Pat. No. 4,792,397 to
Rasmussen and assigned to Harvard Corporation. In that reference,
two outer rings in proximity to each other appear to be disclosed.
One ring does not appear to engage the interstitial layers, but is
located on the outside of the layers of tissue with an overlapping
sheet made from a material typically known under the trademark
"Mylar" to attempt to seal the intersection of the ends of the two
filter elements. A second ring is located proximate to the outer
ring and appears in functional similarity to the ring of the
Rasmussen '204 reference. The Rasmussen '397 reference attempted to
restrict the outer movement of the tissue layers in the filter and
avoid compressing the filter against the container wall causing
difficult removal. This perhaps was a problem in the Schade '400
reference where the filter element may have become lodged against
the container wall and difficult to remove. However, the Rasmussen
'397 reference does not appear to have accounted for circular
inconsistencies in the outer periphery of a wound filter element.
For instance, if the filter element were wound in an oblong
fashion, one of the two seals, if not indeed both of them, might
escape interstitial sealing against the wound layers.
[0022] Thus, the field of the present invention is such that
economics and efficiency are realized by using wound tissue layers.
However, the need still exists for improved leakage control both
between the wound tissues of layers as well as around the sealing
ends of the filter elements.
[0023] Ironically, the development and filtration and improvements
in leakage control have prompted the emergence of previously
unencountered or unnoticed weaknesses in the filtration system.
That is, the more tightly sealed filter elements have been found,
on occasion, to develop axial flow bypass channels down through the
filter elements themselves. These bypass channels may result in
direct, substantially uninhibited, flow communication between the
fluid entry surface and the fluid exit surface by allowing
unfiltered fluid to completely escape filtration. This unexpected
occurrence has presented new problems for filter manufacturers and
developers. Thus, as various problems have been solved, other
problems have developed. The technology has seen an increase of the
need for further leakage control. The present invention fulfills
this extra need.
[0024] Part of the problems remaining from prior endeavors appear
to be caused by not realizing the real world aspects of
manufacturing wound tissue filter elements. Pictorially, this is
represented in FIG. 1. As can be seen, the outer circle could be a
container wall (14), ring, and so forth. The inner circle could be
a ring such as disclosed in the above-references. In some
instances, the ring could engage interstitially a portion of the
filtering medium between the tissue layers (area A). In some
instances, the engagement could be minimal (area B) and in other
instances perhaps not at all (area C). Thus, unfiltered fluid, in
seeking the path of least resistance, could seek out the minimal or
no engagement areas and leak past the rings into the filtered flow
path and contaminate the filtered fluid. The present invention, at
least in one goal, seeks to remedy this apparent deficiency.
[0025] Another aspect that may have been realized by some inventors
and yet not apparently fully resolved is shown in FIG. 2. An
unfiltered flow path (12) containing the unfiltered fluid typically
flows between the container walls (14) and the original outer
periphery (15) of a filter element. However, because of pressure
differences between the unfiltered flow path (12) and the filtered
flow path (12a), a hydraulic flow force (16) may be directed
against the filter element and may compress the wound layers of
tissue (22). This compression may move the original outer periphery
(15) to a new resulting outer periphery (17) of the filter element
after the hydraulic flow force compresses the element. Because the
hydraulic flow force may be strong, this may drive unfiltered fluid
through a leakage channel (18a) into the filtered flow path (12a)
and contaminate the filtered fluid.
[0026] FIG. 3 shows an improvement by using at least two rings, one
non-interstitial ring (15a) and a single interstitial ring (15b).
However, as described in FIG. 2, it appears that the hydraulic flow
force (16) may also force leakage in a similar manner as in FIG. 2.
This may occur for at least two reasons. First, by using a
non-interstitial outer ring, the difficulty of varying thickness
(as described in FIG. 1), does not assure an engagement of a
sufficient amount of wound layers of tissue (22) between the
non-interstitial ring (15a) and single interstitial ring (15b).
Thus, the hydraulic flow force may likewise drive unfiltered fluid
along the similar leakage channel (18a). A second reason is that
there may be a hydraulic flow force that forces the wound layers of
tissue (22) on the inside circumference of the single interstitial
ring (15b) such that a non-engaged area (18) appears. It may be
that this was originally thought to be a seal but appears
ineffective because of the hydraulic flow force (16) compressing
the layers away from this ring or perhaps other reasons.
[0027] Thus, of the solutions found and reviewed, a need still
exists for more effective sealing. The present invention fills this
gap. While the needed implementing arts and elements have long been
available, and a long felt need has existed, no invention appears
to have accomplished the goals and objects of the present
invention. Certainly, those in the field appreciated that a problem
existed and that the problem involved leakage, but were unable to
fully appreciate the solution to the problem. As seen above and in
other areas, substantial attempts were made by those skilled in the
art to fulfill the needs or to cope with the difficulties, but they
either failed to appreciate the full scope of the problem or only
provided a partial solution. Part of this realization may have been
a failure to understand the real world complexities of producing
satisfactory shaped filters of the quality needed, considering the
expense involved. Thus, the present invention seeks to resolve
these issues and provide a simple and economical apparatus and
method.
SUMMARY OF INVENTION
[0028] The invention of the present patent is a practical
invention. It realizes the real world inconsistencies of wound
filter elements and leakage control. The present invention
recognizes the need for proximately compressing interstitially the
wound layers in the filter elements. For instance, other references
generally relied on sealing the filter about the base of a
collector or container in an axial direction by axial compression.
The present invention may not rely, in some embodiments, on axial
compression; it simply may utilize a compressed blocking area in
the filter element. The present invention also recognizes the real
world out-of-roundness that typical filter elements contain and
adjusts accordingly, such that in some embodiments a compressed
area is uniformly compressed about the circumference of the filter
element. This invention also recognizes that it might be
advantageous in forming this compressed area to engage the filter
elements at different points at different periods. For instance, it
may vary the height of interstitial rings to assist in the
compression procedure. The present invention also recognizes the
utility to proximately and interstitially locate at least two rings
such that a compressed area is formed interstitially between the
layers of the filter element (and in some instances assuring that
it is formed interstitially). Furthermore, the present invention
recognizes the utility for secondary and compression tapers which
may appear separately or in combination with different heights and
different engagement points of multiple rings to assist in securing
a compressed area.
[0029] Thus, one goal of the present invention is to provide a
method of filtering a fluid which typically could comprise the
steps of accepting a flow of unfiltered fluid into a container such
as a filtering container, flowing the unfiltered fluid in an
unfiltered flow path in that container, blocking the flow of
unfiltered fluid in a blocking area through some type of action on
or of a filtering medium contained in the container, filtering the
unfiltered fluid to produce a filtered fluid in some filtering area
typically contained within the filtering medium where the filtering
occurs on an opposite side of the blocking area from the unfiltered
fluid, interposing at least a portion of the filtering medium
between the blocking area and the unfiltered area, and allowing the
filtered fluid to pass out of the container. An object of this goal
could be to provide a blocking area having a compressive force
exerted on it that is greater than a hydraulic flow force caused by
the fluid to better effectuate a seal. Such a compressive force
could be in a radial direction and could comprise a radial
compressive force. Another object could be to block the flow by
annularly uniformly compressing the blocking area. Another object
of this goal could be to continuously compress the blocking area.
Still another object could be to compress in a step-wise fashion
the blocking area. Still another object could be to compress the
blocking area in a non-linear fashion, which may or may not include
in a parabolic fashion. Such blocking could occur through the use
of at least two interstitial rings. The blocking area could have a
height to thickness ratio of approximately one-hundred percent
(100%) in that the engaged height of the blocking area through the
use of interstitial rings compared to the thickness of the blocking
area between the interstitial rings could be approximately a ratio
of one. To assist in the engagement, the rings could have different
heights that could interstitially engage the filter element at
different heights to form the blocking area. Another object could
include engaging a first ring before engaging a second ring
interstitially to establish the blocking area. For instance, this
could include engaging a secondary taper on a first ring, then
engaging a secondary taper on a second ring, and then engaging a
compression taper on the first ring. Alternatively, it could
include engaging a secondary taper on the first ring, then engaging
a compression taper on the first ring and then engaging a secondary
taper on the second ring. Another alternative could include
engaging a secondary taper on the first ring, then engaging a
secondary taper on the second ring and then engaging a compression
taper on the second ring. Other variations are possible. Another
object could include establishing the blocking area by the
interactive engagement of a first and second ring. The interactive
engagement can be accomplished by the proximate location of the
first and second ring. Such proximate location of the first and
second ring can function interactively such that the blocking area
is compressed where the blocking area is created to resist the
leakage of unfiltered fluid. Likewise, this blocking area may form
a discreet annular area around the filter element. In some cases,
the blocking area could be approximately one-quarter inch
thick.
[0030] Another goal of the present invention is to filter a fluid
by accepting a flow of unfiltered fluid into a container where the
container contains a filtering medium, flowing the unfiltered fluid
in an unfiltered flow path in the container, engaging a first
interstitial ring to the filtering medium, engaging a second
interstitial ring which is proximate to the first interstitial
ring, interposing at least a portion of the filtering medium
between the first and second interstitial rings and the unfiltered
fluid, filtering the fluid through the filtering medium so that the
filtering occurs on the opposite side of each of the first and
second interstitial rings with respect to the unfiltered fluid, and
allowing the filtered fluid to pass out of the container. Thus, the
invention may include a fluid holding container with an inlet and
an outlet, an unfiltered flow path for unfiltered fluid, a filter
element fluidicly connected to the container comprising a filtering
medium, a first interstitial ring which may interstitially engage
the filtering medium, and a second interstitial ring which may
interstitially engage the filtering medium and may be proximate to
the first interstitial ring. Similar to the other objects, the
rings could have secondary and compression tapers at different
relative heights for engagement at different points on the
filtering medium, could have an average ring height to thickness
ratio of approximately one-hundred percent (100%), could be
approximately one-quarter inch thick, and could form continuously
compressed blocking areas or uniformly compressed blocking
areas.
[0031] Another goal of the present invention is to accept the flow
of unfiltered fluid into a container, flow the unfiltered fluid in
an unfiltered flow path in the container, assure the annular
engagement of a uniform area of filtering medium in a uniform
engaged area, filter the fluid in the filtering medium to produce a
filtering fluid where the filtering occurs on an opposite side of
the uniform engaged area from the unfiltered fluid, and allow the
filtered fluid to pass out of the container. One object of this
goal could include establishing a blocking area from the uniform
engaged area. The blocking area could comprise a uniformly
compressed blocking area. It could also include a ring compression
force acting on the blocking area that is greater than a hydraulic
flow force acting on the filter element.
[0032] Another goal of the present invention is to accept the flow
of unfiltered fluid into a container flow the unfiltered fluid in
an unfiltered path in the container, engage the filtering medium
with the first interstitial ring having a first axial height,
engage the filtering medium with a second interstitial ring at a
second axial height which is different than the first axial height,
filter the unfiltered fluid in a filtering medium, and allow a
filtered fluid to pass out of the container.
[0033] Another goal of the present invention is to accept an
unfiltered fluid into a container, flow the unfiltered fluid in an
unfiltered path in the container, force the flow through a
filtering medium which is substantially parallel to a filtering
flow to produce a filtering fluid, force the unfiltered fluid
through a restrictor element substantially transverse to the
filtering flow, block the flow from flowing around at least one
edge of the restrictor element, and allow the filtered fluid to
pass out of the container. The object of this goal could include
creating a pressure equalization across an end of the substantially
parallel filtering medium using the restrictor element. Another
object of this goal could include blocking the flow around an inner
and an outer edge. Such blocking could occur from a lip having a
curved section on the restrictor element.
[0034] Naturally, further goals and objects of the invention are
disclosed throughout other areas of the specification and
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 represents an out-of-round filter element.
[0036] FIG. 2 represents a prior art non-interstitial ring.
[0037] FIG. 3 represents a prior art non-interstitial ring with a
single interstitial ring.
[0038] FIG. 4 represents a cross section of relevant aspects of the
present invention.
[0039] FIG. 5 represents a detail of the compressed area between
rings.
[0040] Figure 5a represents a cross section of another embodiment
to show an integral fluid collector designed to engage a pair of
filter elements.
[0041] FIG. 6 represents a detail of the secondary and compression
tapers of the rings.
[0042] FIG. 7 represents a cross sectional and area showing a
discreet annular area within the filter element.
[0043] FIG. 8 represents another variation of the secondary and
compression tapers.
[0044] FIG. 8a is another embodiment of a cross section of
rings.
[0045] FIG. 8b is another embodiment of a cross section of
rings.
[0046] FIG. 8c is another embodiment of a cross section of
rings.
[0047] FIG. 8d is another embodiment of a cross section of
rings.
[0048] FIG. 9 represents a cross section of a different
configuration of the filter element (21a) but in other aspects
corresponds to FIG. 7.
[0049] FIG. 10 represents a use of a transverse restrictor element
that may equalize the pressure across a cross sectional area of the
substantially parallel filtering medium and may seal at least one
edge.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] The basic concepts of the present invention may be
implemented in a variety of ways. It may involve the use of two or
more interstitial rings; it may involve the intentional wasting of
a portion of the filter element to create a compressed blocking
area; it may also involve the use of different heights of rings to
accomplish various goals and objects of the present invention and
may include the use of compression and secondary tapers on the
rings. Furthermore, various aspects mentioned above may be
applicable to a variety of devices and where applicable could
include single element filters, multiple element filters, fluidic
filtering systems (which could include gases or liquids) and may
include filtering systems in different industries. It involves both
methods and devices to accomplish the appropriate method. In this
patent, the methods are disclosed as part of the results shown to
be achieved by the various devices described and as steps that are
inherent to utilization of the invention. They may be simply the
natural result of utilizing the devices intended and described. In
addition, while some devices are disclosed, it would be understood
that these not only accomplish certain methods, but also can be
varied in a number of ways. Importantly, as to the foregoing, all
of these facets should be understood to be encompassed by this
patent.
[0051] Having described FIGS. 1-3 above and the various prior
attempts to solve the problems, reference is now directed to FIG.
4. In FIG. 4, a fluid filter (10) is shown. This fluid filter
typically may be pressurized in use and has an axial flow (10b)
through the filter element (22). The fluid (11) enters the inlet
port (19) as shown. It then may flow along the outer periphery of
the filter assembly collectively shown as (21) which may be
comprised of various filter elements such as (21a). The unfiltered
fluid may flow in the unfiltered flow path (12) until reaching a
return point and flowing in the axial flow path (10b) in the filter
element (21a). As the fluid flows between the interstitial wound
layers of tissue (22), impurities are trapped against the surfaces
of the tissue. As fluid flows axially, it may enter the fluid
collector element (24), travel toward the inner core (23), and
enter the filtered flow path (12a). The filtered fluid then may
exit the outlet port (20) into the rest of the fluidic system.
Naturally, if only a single element (21a) were used, then the fluid
collector element (24) could be integral to the fluid container
(13) or could be a separate element as shown perhaps in FIG. 5.
Also, if multiple pairs of filter elements (21a) were used as part
of the filter assembly (21), then more fluid collector elements
(24) would generally be used.
[0052] The fluid collector element (24) as shown in FIG. 4 may
include a substantially flat portion (25). The substantially flat
portion generally may have two sides and at least one of which may
be adapted to face the filter element (21a). In the illustration of
FIG. 4, both sides appear to be adapted to face each filter element
(21a). Either separate or integral to the substantially flat
portion (25) may be a first ring (26) and perhaps a second ring
(30). The rings are described in more detail in FIG. 5 below. One
novel aspect of the present invention is that both rings may be
interstitially oriented to the filter element (21a) and may
interstitially engage the wound layers of tissue (22). It is
believed that by interstitially engaging with at least two rings,
at least two events may occur. First, a blocking area may be
created between the two rings. This blocking area may be compressed
between the two rings. By blocking, it is not meant to be absolute
in the sense of no leakage; it is meant to achieve a substantial
blocking of unfiltered fluid leaking through a leakage channel
(18a). Thus, filtering could occur on at least a portion of the
filtering medium on an opposite side (34a) of the blocking area
(34) from the unfiltered fluid in the unfiltered flow path (12).
The blocking area may be uniformly compressed in that both rings
are interstitial and, thus, any manufacturing tolerances that might
produce an out-of-shape element may be accounted for. A second
event may occur in that an outer ring, by being interstitial, may
allow a portion of the filtering medium to be interposed between
the blocking area and the unfiltered fluid in the unfiltered flow
path (12).
[0053] Referring to FIG. 5, more detail may be seen of at least one
aspect of the present invention. The fluid collector element (24)
is shown in at least two pieces and may include a wire screen (25a)
or other separate member and a substantially flat portion (25)
having two sides, at least one of which may be adapted to face the
filter element and may include a first ring (26) and a second ring
(30). The embodiment shown is certainly not restrictive. For
instance, the embodiment may include a one-piece arrangement, shown
in FIG. 5a. What is important, at least in one aspect, is that the
rings form a blocking area. In the preferred embodiment, it appears
that approximately one-quarter inch thick section of the wound
layers of tissue may be appropriate for some applications. The
blocking area may be interstitial in that an interposed portion
(22a) exists between the unfiltered flow path (12) and the blocking
area (34).
[0054] This blocking area may be interactively established by the
interaction of the first ring (26) and the second ring (30). The
first ring and the second ring are described in more detail in FIG.
6. For effective sealing, it may be advantageous to have a
continuously compressed blocking area. The first ring may have a
first ring height (26a). The second ring may have a second ring
height (30a). An average of the two heights compared to the
thickness of the compressed blocking area in the preferred
embodiment may approximate a one-to-one ratio, i.e., one-hundred
percent (100%). This novel aspect of the present invention differs
from prior efforts that most efforts relied upon axially, not
radially, compressing the fibers to overcome leakage along the
leakage channel (18a) shown in FIGS. 2 and 3. The present invention
seeks to overcome this leakage problem by providing a blocking area
between, for instance, the two rings shown. Obviously, other
blocking area arrangements could be made. It is envisioned that
some action on the filtering medium, such as pre-compressing a
portion of the wound tissues, will be useful for creating the
blocking area. Once the blocking area is created, then the
filtering medium could block the leakage by action of the filtering
medium. The blocking area shown in FIG. 5 may have a radial
compression component in terms of a pre-compressed state between
the two rings before filtering occurs in the filter element. By
pre-compressing a defined interstitial area radially, it is
believed that less dependence upon axial compression is required in
blocking the leakage channel (18a) such as shown in FIGS. 2 and 3.
This aspect, novel to the present invention, sacrifices a portion
of the filtering medium in its efficiency by intentionally not
using a portion of the filter to create a blocking area in order to
secure better purity and avoid less leakage.
[0055] To assure a suitable blocking area, the first ring may be
located a few layers in from the outer periphery of the filter
element to form an interposed section (22a) of a filtering medium
wound layers of tissue (22), shown in FIG. 5. This may insure more
uniformity to the blocking area. In such an instance, filtering
could occur on an opposite side (34a) of both the first and second
rings from unfiltered fluid. Naturally, the order of the first ring
and second ring could be switched so that the second ring is to the
outside of the first ring for the purposes of this disclosure and
the goals and objects of the invention. By interposing a section,
some advantages may result. First, it may be assured that a
blocking area is formed between the two rings (26) and (30). By
interposing such a section, it may be assured that the blocking
area (34) forms a discreet annular area that may be uniformly
compressed. This may reduce the problems discussed related to FIG.
1 in which, because of manufacturing real world tolerances, it may
not necessarily follow that an equal amount of wound tissue fibers
are compressed around the entire blocking area. By interactively
using the first and second ring, or taking some action on the
filtering medium such as squeezing the filtering medium between the
rings, a ring compression force (37) may be formed and may compress
the blocking area. In some instances, it may be such that the ring
compression force is greater than the hydraulic flow force
discussed in FIG. 2 and 3, so that the hydraulic flow force does
not displace the filtering medium and so that leakage through the
leakage channel (18a) of FIGS. 2 and 3 is reduced or eliminated.
This may enable the filter to achieve higher purity in reducing the
filtered fluid contamination due to the leakage channel (18a).
[0056] The first ring, as shown in FIG. 5, may be an outer ring,
although, other configurations are possible. It may extend axially
from the flat portion (25) of the fluid collector element (24) and
may not necessarily be perpendicular to that flat portion.
Similarly, the second ring (30) may be interstitial; it may extend
axially from the flat portion (25) of the fluid collector element
(24) and need not be perpendicular to the flat portion of the
collector. In the preferred embodiment, the second ring (30) may be
proximate to the first ring (26). While in the preferred
embodiment, this proximate distance may be approximately
one-quarter inch, other distances may be possible such that
proximate is intended to include all distances by which the goals
of forming a blocking area are accomplished. As shown in FIG. 5,
the first ring (26) may have a first ring height (26a) that may be
greater than the second ring height (30a). Similarly, other rings
may be formed, either integral to or separate from the fluid
collector element (24). For instance, an inner ring (shown in FIG.
5a), could be formed in the fluid collector closer to the inner
core (23) that could perform other functions. Typically, this inner
ring may not be proximate to the first or second ring because it
may not be advantageous to create another blocking area over an
extended thickness of the filter element and further reduce the
efficiency of the filter element (21a).
[0057] To assist in forming the blocking area, each ring may have
at least one taper. These tapers may be formed on the inner surface
(31) of the second ring (30) or outer surface (32) of the ring. For
the purposes of the present invention, the inner surface is defined
as the surface facing the inner core (23) and the outer surface
(32) is defined as the surface facing the outer periphery of the
filter element (21a). The first ring (26) would similarly have an
inner surface (27) and an outer surface (28). Furthermore, by
interactively establishing a blocking area, the blocking area may
form a discreet annular area, shown in FIG. 7 described below. This
discreet annular area may be annularly uniform in that a uniform
amount of material may be used to create a blocking area around an
annulus of a cross section of the filter element (21a). By annular,
it is meant to include all shapes of elements such as round,
oblong, square, and other geometric shapes.
[0058] Figure 5a shows another embodiment of the present invention
representing an integral molded assembly including the first and
second ring and an inner ring which may be molded to the fluid
collector (24). FIG. 5b shows a plan view of this embodiment. Fluid
collector elements, other then the goals and objects of the present
invention, are known to those in the art and would include such
devices as the Rasmussen '397 reference, the Rasmussen '204
reference, and the McGinness '290 reference disclosed above and
assigned to Harvard Corporation of Evansville, Wis. The embodiment
with an inner ring (here a third ring) may offer additional
benefits in using a restrictor element described in more detail
below in FIG. 10.
[0059] To further clarify the tapers on the inner and outer
surfaces, reference is now made to FIG. 6. The fluid collector
element (24) may comprise a substantially flat portion (25) with at
least one side adapted to face a filter element. The side adapted
to face the filter element may contain two rings as disclosed
above. The first ring (26) may have a substantially perpendicular
outer surface (28) with respect to the substantially flat portion
(25). The inner surface (27) of the first ring (26) may include a
compression taper (39). As shown in FIG. 6, this compression taper
may face the second ring (30). Toward the upper portion of the
first ring (26), a second taper described as a secondary taper (40)
on the first ring may appear. The secondary taper on the first ring
may be sharp and may engage the filter wound layers of tissue (22).
As could be recognized by one skilled in the art, as the first ring
progressively engages interstitially the wound layers of tissue,
the layers typically first engage the secondary taper (40). Then,
as the layers engage the compression taper (39), the entrapped
wound layers of tissue could be forced or compressed against the
secondary ring (30) and its outer surface (32) to create a ring
compression force. In such an embodiment as shown in FIG. 6,
different heights of the first ring may be appropriate compared to
different heights of the second ring. For instance, the first ring
height (26a) may be higher than the second ring height (30a). This
may assist in engaging the wound layers of tissue first with the
first ring (26) with a secondary taper (40) at a first ring height
(26a), then engaging the second ring (30) at its second ring height
(30a), and then engaging the compression taper (39) on the first
ring, so that the wound layers of tissue are entrapped and can be
compressed between the compression taper (39) on the first ring and
the outer surface (32) on the second ring (30).
[0060] Typically, the wound filter elements are flat on their ends.
Thus, by changing the heights of the various tapers on each or both
rings, the order in engagement can be altered. Naturally, if the
ends of the wound layers of tissue were not flat, then the order of
engagement could also be varied through that means. Thus, the
heights, as described herein, should be understood to encompass a
relative order of engagement and not necessarily a fixed height
with relationship to each ring.
[0061] Obviously, other variations of engagement are possible, some
of which will be described below. It may be useful to also include
a secondary taper (41) on the second ring (30) to assist in
interstitially engaging the wound layers of tissue. The compression
taper height (26b) on the first ring (26) may be higher or lower
than the second ring height (30a) or the compression taper height
(30b) on the second ring (30) depending on the order of engagement
desired.
[0062] While the creation or compression of a blocking area has
been described in terms of a combination or an interactive
combination of a first and second ring, more generally, this
feature may be referred to as a uniform compression element which
could include sub-elements such as the first and second rings.
Other embodiments of a uniform compression element may occur. A key
for a uniform compression element is to assure that a uniform
amount of tissue layers are engaged even when the periphery of the
wound filter element (21a) may be out of shape. One approach for
achieving a more "uniform" amount is to begin the engagement of the
tissue layers interstitially at least a few layers from the
periphery and the locate the annular area entirely interstitially.
This is illustrated in FIG. 7 where the discreet annular area (36)
may be an annularly uniform amount. By the term "assure", it is
meant to include a high probability of creating, in this case, a
uniform area of engagement. Similarly, a uniform compression
element could increasingly compress as it engages the wound
tissues. As described below, this compression may be continuous,
linear, step-wise, or other appropriate modes. Also, it may be
non-linear such as would accompany a curved compression taper and
could include parabolic shapes and other combinations.
[0063] FIG. 8 shows at least one alternative of the engagement ring
heights. In FIG. 8, (assuming a flat end of the filter element
(21a)), the engagement order could be as follows: first, the filter
element might engage the secondary taper (40) on the first ring
(26), then engage the compression taper (39) on the first ring with
a height (26b), then engage the secondary taper (41) on the second
ring (30) with a height (30a). Thus, the first ring height (26a)
would be higher than the compression taper height (26b) which in
turn would be higher than the second ring height (30a) on the
second ring (30). FIG. 8 also changes (as an example of variations
possible) the orientation of the secondary taper (41) which faces
the first ring (26), compared to FIG. 6. Various combinations could
be made such as may be dictated by manufacturing concerns, economy,
and efficiency. FIG. 8 shows a somewhat linear compression taper
(39). Thus, upon engagement, the embodiment of FIG. 8 may allow for
continuously compressing the filter element between the first ring
and the second ring. This compression may occur in a somewhat
linear fashion, although certainly other configurations are
possible.
[0064] FIG. 8a shows another configuration of the cross section of
compression and secondary tapers. In FIG. 8a (as well as in FIGS.
8b and 8c), the compression taper is shown on the first ring;
however, it could be placed on the second ring (and other rings) as
well (Such as shown in FIG. 8d). Therefore, any discussion in this
patent regarding the first ring and its configuration may be
applicable to the second ring. In FIG. 8a, the secondary taper (40)
may terminate at a height (26b) from the flat portion (25). From
that point to the flat portion (25), the compression taper may be
non-linear. This may, for instance, offer a rate of compression
that would be greater at the beginning of the engagement and taper
off toward the end of the engagement.
[0065] FIG. 8b shows a step-wise compression taper that starts at a
height (26b) at the lower end of the secondary taper (40). A first
step (39a) may offer a decreased rate of compression compared to
the second step (39b). Obviously, single or multiple steps could be
used.
[0066] FIG. 8c shows still another configuration of the compression
taper beginning at height (26b) from the flat portion (25). This
taper may be non-linear similar to the taper of FIG. 8a but offer
an inverse relationship compared to FIG. 8a. Obviously, it could
vary from such a relationship. It may be non-linear or it may be
parabolic in that the resulting forces applied to the blocking
area, as the ring engages the wound tissue, may be non-linearly or
parabolically increased as the engagement continues to terminate at
the flat portion (25).
[0067] FIG. 8d shows yet another alternative. In that embodiment,
the first ring height (26a) at the tip of a secondary taper on the
first ring (26) might be higher than the second ring height (30a)
on the second ring (30) which in turn might be higher than the
lower end of the secondary taper at (26b) of the first ring (26),
which in turn might be higher than the compression taper height
(30b) on the second ring. Thus, in this embodiment, the compression
taper would be part of the second ring to compress toward the first
ring.
[0068] As can be seen, various embodiments are possible depending
on whether the compression is performed by the first ring or second
ring, depending on whether the blocking area is formed by a
compression taper on the first ring or the second ring, or
depending on which ring is engaged first and which taper is
engaged. The above embodiments are simply illustrative of various
aspects of engaging a discreet portion between two rings which
generally may include compressing the discreet portion along a
compression taper.
[0069] The compression taper in the preferred embodiment may be at
an angle of approximately six degrees. The secondary taper may be
at an angle of approximately twenty-five to thirty degrees.
Obviously, other variations are possible. In the preferred
embodiment, it has observed seen that the first ring height (26a)
may be approximately 0.28 inches high, the second ring height (30a)
may be approximately 0.21 inches high with an average height of
approximately 0.25 inches. The thickness of each ring may be
approximately 0.06 inches thick. If a proximate distance between
the rings was approximately 0.25 inches, then the average ring
height to thickness ratio of the blocking area would approximately
be one-hundred percent or a 1:1 ratio. While the preferred
embodiment may have different ring heights, certainly it would be
possible for the rings to have the same heights and still meet with
various goals and objects of the present invention. Likewise, the
different compression tapers and secondary tapers could be located
on the outer surfaces or inner surfaces of each ring, as might be
dictated by various concerns to establish a blocking area.
[0070] Referring to FIG. 9, the present invention is not restricted
to a circular wound element. For instance, it may be comprised of a
square, rectangular, oval, or other shaped wound filter element as
may be desired. The market place and competitive efficiencies may
dictate the particular shape. However, the goals and objects of the
present invention may be met accordingly, for instance, by
providing a blocked area for sealing against the leakage of
unfiltered fluid into filtered fluid, or by providing interstitial
rings, or other goals and objects of the present invention. FIG. 9
has, similar to FIG. 7, a cross sectional view showing the blocking
area as a discreet annular area (36) having a thickness (35) which
may be formed interstitially from the outer periphery of the filter
element (15) on the filter element (21a).
[0071] FIG. 10 shows another aspect of the present invention. In
FIG. 10, the filtering element is designated (45) which is
nominated a substantially parallel filtering medium and is
substantially parallel with respect to the filtering flow path
(45a). This may include the type of wound layers of tissue type
elements described above and nominated as filter (21a) element. The
flow through the filter assembly (21), and typically through the
substantially parallel filtering medium (45) in an axial flow
direction, may cause channeling within the wound layers of tissues
themselves. Once the channel or separation between the wound layers
of tissue occurs, less filtration may be possible. Thus, it may be
advantageous to include a restrictor element (46) to deter
unfiltered fluid from contaminating filtered fluid due to
channeling. This restrictor element may also attempt to better
equalize the pressure across a cross sectional area of the filter
element (45) to lessen the risk of channeling.
[0072] The substantially transverse restrictor element (46)
typically is perpendicular with respect to the filtering flow path
(45a). By "transverse" it is meant to include an alignment at any
angle transverse to the primary axial flow of filtration.
Typically, the restrictor element (46) may be made of material of
greater porosity than the filtering element (21a) such that the
flow is not unduly hindered, yet assistive in reducing channeling.
Additionally, one novel aspect of the present invention helps seal
around the edge of the restrictor element (46) such that the
unfiltered flow does not bypass or at least is reduced.
[0073] Unique to the present invention, it incorporates, at least
on one side, a lip (47) that rolls toward the filtering tissues
(21a). This may be used in conjunction with an inner ring (52)
(here a third ring) on the inner surfaces and perhaps a second ring
(30) on the outer surfaces. The inner ring may be interstitial.
Obviously, other combinations are possible. With the lip (47) shown
protruding upwards toward the filter element (45a), the pressure
(51) from the fluid flow helps seal the lip against the ring and
therefore seal between the interstitial wound layers of tissues,
thus reducing leakage between the restrictor element 46 and the end
of the filter element (21a) into the filtered flow path. Obviously,
both edges of the substantially transverse restrictor element (46)
could have a lip, shown on the inner edge (49) and the outer edge
(50). Thus, by using this device, the pressure may be more
equalized and inhibit channeling and perhaps prolong the life of
the filtering element by distributing the filtration across the
substantially parallel filtering medium (45). This invention, by
inclusion of the lip in conjunction with the rings in at least one
embodiment, may also reduce the leakage across this restrictor
element.
[0074] Each of these pressurized axial flow fluid filters could
include various facets of the present invention. Some may include a
blocking area, others may include interstitial rings, and still
others may include combinations of both. Some may include varieties
of restrictor elements, depending on the particular desires and
concerns. The market place and manufacturing concerns may dictate
the appropriate embodiments for the present invention.
[0075] The foregoing discussion and the claims that follow describe
only the preferred embodiments of the present invention.
Particularly with respect to the claims, it should be understood
that a number of changes may be made without departing from the
essence of the present invention. In this regard, it is intended
that such changes--to the extent that they substantially achieve
the same results in substantially the same way--will still fall
within the scope of the present invention. It is simply not
practical to describe in the claims all the possible embodiments to
the present invention which may be accomplished generally in
keeping with the goals and objects of the present invention and,
thus, disclosure which may include, separately and collectively,
such aspects as blocking the flow of unfiltered fluid in a blocking
area, interposing a portion of the filtering medium between a
blocking area and the unfiltered fluid, compressing the blocking
area, engaging a first interstitial ring and a second interstitial
ring within the wound layers of tissue, assuring the annular
engagement of a uniform area of filtering medium, engaging
filtering medium with interstitial rings having different axial
heights, and forcing flow through a restrictor element with a lip,
and forcing flow through a substantially parallel filtering medium
within the same filtering assembly, or others. These aspects,
separately or in various combinations, may be included in each of
the claims. To the extent the methods claimed in the present
invention are not farther discussed, they are natural outgrowths of
the system or apparatus claimed. Therefore, separate and further
discussion of the methods are deemed unnecessary as they otherwise
claim steps that are implicit in the use and manufacture of the
system or the apparatus claims. Without limitation, the present
disclosure should be construed to encompass subclaims similar to
those presented in each of system, apparatus, or method claims that
could be applicable to the other system, apparatus, or method
claims. Furthermore, the steps are organized in a more logical
fashion; however, other sequences can and do occur. Therefore, the
method claims should not be construed to include only the order of
sequence and steps presented.
[0076] As mentioned earlier, this invention can be embodied in a
variety of ways. In addition, each of the various elements of the
invention and claims may also be achieved in a variety of manners.
This disclosure should be understood to encompass each such
variation, be it a variation of an embodiment of any apparatus
embodiment, a method or process embodiment, or even merely a
variation of any element of these. Particularly, it should be
understood that as the disclosure relates to elements of the
invention, the words for each element may be expressed by
equivalent apparatus terms or method terms--even if only the
function or result is the same. Such equivalent, broader, or even
more generic terms should be considered to be encompassed in the
description of each element or action. Such terms can be
substituted where desired to make explicit the implicitly broad
coverage to which this invention is entitled. As but one example,
it should be understood that all action may be expressed as a means
for taking that action or as an element which causes that action.
Similarly, each physical element disclosed should be understood to
encompass a disclosure of the action which that physical element
facilitates. Regarding this last aspect, the disclosure of a
"blocking area" should be understood to encompass disclosure of the
act of "blocking"--whether explicitly discussed or not--and,
conversely, were there only disclosure of the act of "blocking",
such a disclosure should be understood to encompass disclosure of a
"block" or "blocking area." Such changes and alternative terms are
to be understood to be explicitly included in the description.
[0077] Furthermore, any references mentioned in the application or
this patent, as well as all references listed in any information
disclosure originally filed with the application, are hereby
incorporated by reference in their entirety to the extent such may
be deemed essential to support the enablement of the invention(s).
However, to the extent statements may be considered inconsistent
with the patenting of this/these invention(s), such statements are
expressly not to be considered as made by the applicant(s).
* * * * *