U.S. patent application number 09/795745 was filed with the patent office on 2001-07-19 for filter apparatus.
Invention is credited to Drori, Mordeki.
Application Number | 20010008219 09/795745 |
Document ID | / |
Family ID | 27533541 |
Filed Date | 2001-07-19 |
United States Patent
Application |
20010008219 |
Kind Code |
A1 |
Drori, Mordeki |
July 19, 2001 |
Filter apparatus
Abstract
A fluid filter comprising a housing defining a fluid inlet and a
fluid outlet, a filter element defining an upstream surface
communicating with the fluid inlet and a downstream cylindrical
surface communicating with the fluid outlet, the filter element
comprising a stack of filter disks defining a hollow volume
interiorly thereof and a longitudinal axis, and backflushing means
for removing filtered out sediment from the filter element
comprising an axially displaceable backflushing nozzle assembly
disposed within the hollow volume comprising a rotating head
coupled to the fluid inlet and having fluid outlet means, arranged
to provide a generally radially directed pressurized jet and
rotational motion of the rotating head.
Inventors: |
Drori, Mordeki; (Mentor,
OH) |
Correspondence
Address: |
Paul R. Steffes, Esq.
Renner, Otto, Boisselle, & Sklar, L.L.P.
1621 Euclid Avenue, 19th Floor
Cleveland
OH
44115
US
|
Family ID: |
27533541 |
Appl. No.: |
09/795745 |
Filed: |
February 28, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09795745 |
Feb 28, 2001 |
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09229228 |
Jan 12, 1999 |
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09229228 |
Jan 12, 1999 |
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08660450 |
Jun 7, 1996 |
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5858231 |
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08660450 |
Jun 7, 1996 |
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08381014 |
Jan 30, 1995 |
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5545321 |
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08381014 |
Jan 30, 1995 |
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08150582 |
Nov 9, 1993 |
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08150582 |
Nov 9, 1993 |
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07943132 |
Sep 10, 1992 |
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07943132 |
Sep 10, 1992 |
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07479057 |
Feb 12, 1990 |
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07479057 |
Feb 12, 1990 |
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07013248 |
Feb 10, 1987 |
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4935126 |
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Current U.S.
Class: |
210/411 ;
210/413; 210/435 |
Current CPC
Class: |
B01D 29/15 20130101;
B01D 25/26 20130101; B01D 25/30 20130101; B01D 25/327 20130101;
B01D 29/902 20130101; B01D 29/94 20130101; B01D 25/307 20130101;
B01D 29/46 20130101; B01D 29/885 20130101; B01D 29/90 20130101;
B01D 29/682 20130101; B01D 2201/084 20130101; B01D 29/684
20130101 |
Class at
Publication: |
210/411 ;
210/413; 210/435 |
International
Class: |
B01D 025/32 |
Claims
What is claimed is:
1. A filter comprising: a housing in communication with an inlet, a
drain and an outlet and having an upper aperture; a filter element
disposed in said housing for separating particles from the fluid
flowing from said inlet passage through said filter element to said
outlet passage and having an external circumferential surface and
an internal cylindrical surface defining a hollow internal volume
and a central axis, one of said surfaces being in communication
with the outlet and the other surface being in communication with
the inlet and with the drain; and a movable cleaning mechanism
comprising a hollow longitudinal means extending through said upper
aperture, one end of said longitudinal means being connected to a
rotatable discharge device disposed in said internal volume and
having at least one opening for discharging a tangential jet, the
other end of said longitudinal means being connected to an external
means adapted to communicate with an external pressurized fluid
source and with an external source of power such that during a
cleaning operation said external source of power effects the linear
movement of said rotatable discharge device and simultaneously the
pressurized fluid flowing from said external pressurized fluid
source discharged from said opening effects the rotational movement
of said rotatable discharge device around said central axis within
said internal volume.
2. The filter of claim 1 wherein said rotatable discharge device
comprises at least one additional opening for discharging a jet of
pressurized fluid to splash on the inner surface of said filter
element.
3. The filter of claim 2 wherein said additional opening is adapted
to discharge a substantially direct jet of pressurized fluid to
splash along the inner surface of said filter element to dislodge
particles accumulated on said filter element.
4. The filter of claim 1 wherein at least two openings are defined
on said rotatable discharge device, one of said openings being
adapted to discharge a tangential jet of pressurized fluid to
effect the rotational movement of said rotatable discharge device,
the other opening being adapted to splash pressurized fluid on the
inner surface of said filter element.
5. The filter of claim 1 wherein at least one opening for
discharging a tangential jet is defined on said rotatable discharge
device and at least one additional opening is defined on said
rotatable discharge device adapted to discharge pressurized fluid
to splash on the inner surface of said filter element to dislodge
particles accumulated on the filter element.
6. The filter of claim 1 wherein at least two eccentric openings
are defined on said discharge device and are adapted to discharge
pressurized fluid in the form of tangential jets.
7. A filter comprising: a housing having an inlet passage, an
outlet passage and an aperture; a filter element disposed within
said housing in order to separate particles from the fluid flowing
from said inlet passage through said filter element to said outlet
passage said filter element having an external circumferential
surface and an internal cylindrical surface defining a hollow
internal volume and a central axis interiorly thereof, one of said
surfaces being in communication within the inlet passage and the
other surface being in communication with the outlet passage; and a
displaceable discharge mechanism comprising a hollow means
extending through said aperture, one end of said hollow means being
connected to an external means adapted to communicate with an
external source of pressurized fluid and an external source of
power, the other end being connected to a rotatable discharge
device disposed in said internal volume and having at least one
eccentric opening for discharging an eccentric jet; characterized
in that during a cleaning operation said external power source
effects a linear movement of said rotatable discharge device and
simultaneously pressurize fluid from said external source of
pressurized fluid flowing through said eccentric opening effects
the rotation of said rotation of said rotatable discharge device
around the central axis.
8. The filter of claim 7 wherein said rotatable discharge device
defines at least one additional opening adapted to splash a jet on
the internal surface of said filter element in order to sweep
particles from the filter element.
9. The filter of claim 7 wherein said rotatable discharge device
comprises at least two first and second openings for discharging
pressurized fluid, the first opening being adapted to effect the
rotational movement of said rotatable discharge device and the
second opening being adapted to discharge a jet of pressurized
fluid to splash on the internal surface of said filter element in
order to dislodge particles accumulated on said filter element.
10. The filter of claim 7 wherein said rotatable discharge device
comprises at least two eccentric openings adapted to discharge
pressurized fluid in order to rotate said rotatable discharge
device and to dislodge particles accumulated on said filter
element.
11. The filter of claim 7 wherein said rotatable discharge device
comprises at least two nozzles adapted to discharge tangential jets
of pressurized fluid.
12. The filter of claim 7 wherein said rotatable discharge device
comprises at least one opening adapted to splash a jet of
pressurized fluid on said internal cylindrical surface of said
filter element in order to dislodge the accumulated particles from
said filter element.
13. The filter of claim 12 wherein said rotatable discharge device
comprises at least one eccentric nozzle to effect the rotational
movement of said discharge device and at least one nozzle adapted
to splash pressurized fluid jet on said inlet cylindrical surface
of said filter element in order to dislodge accumulated particles
from said filter element.
14. A filter apparatus comprising: a housing having an inlet
passage and a drain passage for nonfiltered fluid, an outlet
passage for the filtered fluid and an upper aperture; a filter
element disposed within said housing in order to separate particles
from the fluid flowing from said inlet passage through said filter
element to said outlet passage, said filter element having a
circumferential external surface and an internal cylindrical
surface defining a hollow internal volume and a central axis, one
of said surfaces being in communication with the outlet passage and
the other surface being in communication with the inlet and drain
passages; and a cleaning mechanism comprising a hollow means
extending through said aperture and connected on one end to an
external means adapted to be in communication with an external
source of pressurized fluid and an external source of power, and on
the other end to a discharge device disposed in said internal
volume having at least one opening for discharging pressurized
fluid; characterized in that during a cleaning operation said
external source of power effects the linear movement of said
discharge device and simultaneously pressurized fluid from said
external pressurized fluid source discharged from said opening
splashes fluid on said internal cylindrical surface of said filter
element.
15. The filter of claim 14 wherein said discharge device comprises
at least two openings for discharging pressurized fluid to impinge
the internal surface.
16. The filter of claim 14 wherein said discharge device comprises
at least one eccentric opening to discharge an eccentric jet.
17. The filter of claim 14 wherein said discharge device comprises
at least one opening adapted to discharge a tangential jet.
18. The filter of claim 16 wherein said eccentric jet effects the
rotational movement around the central axis of said discharge
device.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to filters and particularly
too multiple-disk type filters useful in filtering particles from
water and in many other applications.
BACKGROUND OF THE INVENTION
[0002] Multiple-disk type filters generally include a housing in
which the filter body within the housing is in the form of a stack
or like, centrally-apertured, filter disks of substantially uniform
thickness along their widths and having grooved side faces defining
filtering channels between the adjacent disks in the stack. In some
applications of such filters, the outer face of the stack of filter
disks constitutes the upstream side of the filter, in which case
the fluid being filtered passes from the outer face to the inner
face of the stack. In other applications of such filters, the inner
face of the stack constitutes the upstream side of the filter, in
which case the fluid being filtered passes from the inner to the
outer face through the filter stack.
[0003] Multiple-disk type filters have a number of advantages over
other known types of filters, for example, the cylindrical-screen
type filter. The multiple-disk filter has a larger capacity for
removing and retaining dirt particles, since these may be retained
also between the side faces of the disks, in addition to being
retained on the upstream surface as in the cylindrical-screen type
filter. Another advantage in the multiple-disk filter is that it is
not as easily ruptured as the screen type and therefore there is
less danger that because of a malfunction, unfiltered water may
pass through and clog sprinklers or other devices downstream of the
filter. The latter advantage is particularly important in
self-cleaning filters wherein the upstream face of the filter is
cleaned by a cleaning nozzle which, in the case of a screen-type
filter, may rupture the screen by particles becoming wedged between
the cleaning nozzle and the filter screen.
[0004] Back-flushable filters of various types are well known in
the art for a great variety of applications. A particularly
successful type of backflushable filter employing filter disks is
described and claimed in the following patents of applicant: U.S.
Pat. Nos. 4,026,806; 4,042-504; 4,045.345; 4,271,018;
4,295.963.
SUMMARY OF THE INVENTION
[0005] There is provided in accordance with a preferred embodiment
of the invention a fluid filter comprising a housing defining a
fluid inlet and a fluid outlet; a filter element defining an
upstream surface communicating with the fluid inlet and a
downstream surface communicating with the fluid outlet, the filter
element defining a hollow volume interior thereof; and backflushing
apparatus associated with the filter element, the fluid inlet and
the fluid outlet.
[0006] The present invention also provides an improved disk-type
filter including a housing having an inlet connectable to an
upstream pipe, and an outlet connectable to a downstream pipe; and
a stack of disks disposed within the housing for separating solid
particles from a fluid flowing between the disks from the upstream
side of the stack to the downstream side thereof; characterized in
that a filter aid is associated with the stack.
[0007] A filter aid is a finely divided solid, which may be
precoated on the filter support, and is usually also mixed with a
liquid to be filtered. It may also be a liquid, which is mixed with
the liquid to be filtered. In the process of filtration, both the
filter aid and foreign solids are removed from the liquid, and the
filter aid, added to the liquid gradient, forms a rigid, permeable,
incompressible "cake" on the filter. Whatever fine solids were
originally suspended in the liquid are entrained in the cake as it
is built up. The porous nature of the cake prevents such solids
from agglomerating and forming an impervious layer on the filter.
This porous, bulky cake makes filtration more rapid and efficient
than it would have been in the absence of a filter aid and greatly
increases the time which elapses before the filter becomes
clogged.
[0008] Various types of filter aid are known, including
diatomaceous earth, plastic-coated diatomaceous earth, diatomaceous
silica, bentonites, carbon, asbestos, cellulose, pumice, pumicite,
obsidian, pitchstone, volcanic ash, volcanic glass, attapulgite
clay, wood pulp, fly ash, kieselguhr, or calcium hypochlorite.
[0009] Filter aids are disclosed in the following US patents, the
techniques of which are incorporated herein by reference: U.S. Pat.
No. 2,508,602 to Goets, re-issue Pat. No. 26,709 to Vander Linden;
U.S. Pat. No. 3,282,435 to Goldberg et al.; U.S. Pat. No. 3,278,450
to Goldberg et al.; U.S. Pat. No. 3,233,741 to Bell et al.; U.S.
Pat. No. 2.956,016 to Leppla et al.; U.S. Pat. No. 2,926,137 to
Calvert; U.S. Pat. No. 2,892,240 to Frankenhoff; and U.S. Pat. No.
2,696,306 to Gomory.
[0010] The backflushing apparatus includes inlet pressure
responsive valve apparatus operative to open in response to a
selected inlet pressure so as to permit fluid flow into engagement
with the upstream surface and to close in the absence the selected
inlet pressure, preventing backflow of fluid from the interior of
the housing to the inlet.
[0011] In accordance with a preferred embodiment of the invention,
the pressure responsive valve apparatus includes means for
deflecting fluid entering the housing via the inlet from direct
impingement with the facing upstream surface of the filter
element.
[0012] Additionally in accordance with a preferred embodiment of
the present invention the inlet pressure responsive valve apparatus
includes apparatus for providing fluid coupling between the
interior of the housing adjacent the upstream surface and a
backflushing outlet when the valve apparatus closes off the fluid
inlet from the interior of the housing.
[0013] Further in accordance with a preferred embodiment of the
invention, the filter element is of generally cylindrical
configuration defining an upstream cylindrical surface and a
downstream cylindrical surface.
[0014] Additionally in accordance with a preferred embodiment of
the present invention, the backflushing apparatus comprises a
backflushing nozzle normally disposed within the hollow cylindrical
volume and comprising a rotating head having fluid outlet means
arranged to provide a generally radially directed presssurized jet
and rotational motion of the rotating head.
[0015] The present invention also seeks to provide a backflushable
filter, preferably of the disk type, which is suitable for any
water filtration system, and which is characterized by a filter aid
being associated with the filter.
[0016] The present invention also provides a backflushable filter,
preferably of the disk type, which is suitable for any water
filtration system such as that used for a health tub or pool, and
is particularly suitable for household use, in that it can readily
be cleaned to a pristine state, without substantial
disassembly.
[0017] There is also provided in accordance with an embodiment of
the invention a filter element comprising a multiplicity of
disk-like elements of a porous material separated by a multiplicity
of grooved spacer elements, each spacer element defining axially
tapered generally radially extending grooves.
[0018] Additionally in accordance with a preferred embodiment of
the invention, each spacer element defines on a first side thereof
axially tapered generally radially extending grooves opening to a
downstream side and on a second side thereof axially tapered
generally radially extending grooves opening to an upstream
side.
[0019] Further in accordance with an embodiment of the invention,
the grooves on the first and second sides are skewed with respect
to each other so as to provide structural strength to the spacer
elements.
[0020] In accordance with a preferred embodiment of the present
invention the grooves disposed on opposite sides of the disk of
porous material are arranged in mutually skewed orientation such
that each groove on a given side of the porous material overlaps at
least two and preferably three grooves on the opposite side of the
porous material.
[0021] The above arrangement enables fluid passing through the
filter element during normal filtering operation to enter through
any given groove and, after passing through the porous material to
drain from the filter element through a plurality of channels, thus
enabling clogged or blocked channels to be bypassed and greatly
extending the filtration capacity of the filter element.
[0022] The above arrangement also enables backflushing fluid
passing through the filter element during backflushing operation to
enter from the downstream side at any given groove and after
passing through the porous material to drain from the filter
element through a plurality of channels, thus increasing the
efficiency of backflushing operation.
[0023] Additionally in accordance with an embodiment of the
invention, the grooves taper downwardly from a maximum adjacent
their opening. Further in accordance with an embodiment of the
invention the grooves are terminated at the end opposite their
opening, thus requiring all fluid to pass through the porous
material.
[0024] Further in accordance with a preferred embodiment of the
present invention there are defined first and second peripheral
sealing bands on the first side of the spacer element and third and
fourth peripheral sealing bands on the second side of the spacer
element. The sealing bands provide sealing engagement with porous
material interposed between adjacent stacked disks, whereby fluid
entering a groove at an upstream side of the filter element during
normal filtering may only exit the groove via the porous material
to the downstream side of the filter element and whereby fluid
entering a groove at a downstream side of the filter element during
backflushing can only exit the groove via the porous material to
the upstream side of the filter element.
[0025] The first and second rings are located at respective
upstream and downstream radial locations on the first side of the
disk. The third and fourth rings are located at respective upstream
and downstream radial locations on the second side of the disk. The
third and fourth rings are each typically radially offset outwardly
with respect to the respective corresponding first and second
rings, such that the first and third rings lie in adjacent
relationship on opposite sides of the disk and the second and
fourth rings lie in adjacent relationship on opposite sides of the
disk.
[0026] The sealing rings are generally coplanar with the upstanding
portions adjacent thereto.
[0027] There is also provided in accordance with a preferred
embodiment of the present invention, a backflushable filter
defining an inlet and an outlet and comprising a filter element
defining an upstream side arranged to receive a flow of fluid to be
filtered from the inlet, and a downstream side arranged to be
coupled to the outlet, the filter element being arranged about a
longitudinal axis; apparatus for providing a concentrated,
relatively high pressure flow of backflushing liquid to the Filter
element directed from the downstream side to the upstream side nad
arranged to be axially movable, parallel to the longitudinal axis
such that the relatively high pressure flow sequentially engages
different regions of the filter element for sequential backflushing
thereof.
[0028] Additionally in accordance with an embodiment of the
invention, the filter apparatus also comprises a one way valve
apparatus permitting high pressure flow to bypass the filter
element from the inlet to the outlet.
[0029] According to a preferred embodiment of the present
invention, the one way valve comprises a first one way valve such
as a pressure valve arranged between the inlet and the downstream
side and a second one way valve such as a check valve arranged
between the outstream side and the outlet.
[0030] There is also provided in accordance with a preferred
embodiment of the present invention, a disk-type filter including a
housing having an inlet connectable to an upstream pipe, and an
outlet connectable to a downstream pipe; and a stack of disks
disposed within the housing for separating solid particles from a
fluid flowing between the disks from an upstream side of the stack
to a downstream side thereof; characterized in that the stack
includes a plurality of co-operating filter elements defining a
plurality of paired co-operating filter surfaces, including a first
surface defining a plurality of spaced, generally circumferentially
extending raised line portions separated by generally
circumferentially extending grooves and a second surface defining a
plurality of generally radially extending fingers each outlined by
a raised line portion having a notched configuration, the exterior
of the fingers communicating with either one of the upstream side
or the downstream side and the interiors of the fingers
communicating with the other one of the upstream side or the
downstream side.
[0031] In accordance with a preferred embodiment of the present
invention, the raised line portion on the second surface defines a
filtering barrier between the upstream side and the downstream
side. Further in accordance with an embodiment of the invention,
the notched configuration of the raised line portion on the second
surface defines an enhanced length filtering barrier.
[0032] Additionally in accordance with a preferred embodiment of
the present invention, the thickness of the raised line portion on
the second surface is less than the separation between adjacent
line portions. Preferably, the thickness of the raised line portion
on the second surface is approximately one half or less than the
separation between adjacent line portions, thus enabling a
relatively high density of filtering barrier to be defined on a
given area of filter disk.
[0033] Further in accordance with an embodiment of the invention,
the raised line portion is of generally uniform thickness, thus
providing a filtering barrier of generally uniform
characteristics.
[0034] In accordance with a preferred embodiment of the invention,
the raised line portion on the second surface is continuous along
the entire second surface and defines a closed loop.
[0035] In accordance with a preferred embodiment of the present
invention the stack of disks comprises first and second disk types,
the first disk type being formed with first filter surfaces on both
of its planar surfaces and the second disk type being formed with
second filter surfaces on both of its planar surfaces.
[0036] In accordance with this preferred embodiment, the radially
extending raised line portions on the two second surfaces of the
second disk type defining the fingers are preferably displaced in
respective out of phase relationship. This arrangement provides
enhanced structural strength of the second disk type and obviates
the requirement for a predetermined relative azimuthal arrangement
of disks in a stack.
[0037] There is also provided in accordance with a preferred
embodiment of the invention a fluid filter comprising a housing
defining a fluid inlet and a fluid outlet, a filter element of
generally cylindrical configuration defining an upstream
cylindrical surface communicating with the fluid inlet and a
downstream cylindrical surface communicating with the fluid outlet,
the filter element defining a hollow cylindrical volume interior
thereof, a backflushing nozzle normally disposed within the hollow
cylindrical volume and comprising a rotating head having fluid
outlet means arranged to provide a generally radially extending
stream and rotational motion of the rotating head.
[0038] Additionally in accordance with a preferred embodiment of
the invention, the backflushing nozzle also includes a centering
base member which is apertured to permit passage of fluid
therepast.
[0039] Further in accordance with a preferred embodiment of the
present invention, the housing is formed of a main portion and a
top portion and rod means are provided for securing the filter
element to the housing and the top portion onto the main
portion.
[0040] According to a preferred embodiment of the present
invention, the filter element comprises a disk-type filter element
and includes a stack of disks.
[0041] In this embodiment, the rod means are also operative for
securing the disks in the stack together.
[0042] According to a further preferred embodiment of the present
invention, the rotating head comprises first and second liquid
outlets, the first outlet being arranged to provide a radially
extending stream and the second outlet arranged to provide a
tangentially directed stream for driving the rotating head in
rotational motion.
[0043] There is also provided in accordance with a preferred
embodiment of the invention a fluid filter comprising a housing
defining a fluid inlet and a fluid outlet, a filter element of
generally cylindrical configuration defining an upstream
cylindrical surface communicating with the fluid inlet and a
downstream cylindrical surface communicating with the fluid outlet,
the filter element defining a hollow cylindrical volume interior
thereof, a backflushing nozzle normally disposed within the hollow
cylindrical volume and comprising a rotating head having fluid
outlet means arranged to provide at least one generally outwardly
radially extending stream.
[0044] In accordance with this preferred embodiment of the
invention, the filter element defines a multiplicity of generally
outwardly radially extending filtering chambers which are arranged
such that the at least one stream, when impinging thereon, is
directed therethrough for enhanced backflushing operation.
[0045] Further in accordance with this preferred embodiment of the
invention, the fluid outlet means are preferably configured to have
a configuration such that along the dimension of the longitudinal
axis of the the cylinder of the filter element, the extent of the
stream is such that it may be directed onto a single filtering
chamber for enhanced backflushing operation.
[0046] Additionally in accordance with this preferred embodiment of
the invention, the fluid outlet means comprise first and second
fluid outlets, producing respective first and second radially
extending streams which are directed in generally parallel planes
spaced from each other along the longitudinal axis of the
cylinder.
[0047] Further in accordance with a preferred embodiment of the
invention there is provided a fluid filter comprising a housing
defining a fluid inlet and a fluid outlet, a filter element of
generally cylindrical configuration defining an upstream
cylindrical surface communicating with the fluid inlet and a
downstream cylindrical surface communicating with the fluid outlet,
the filter element defining a hollow cylindrical volume interior
thereof, a backflushing nozzle normally disposed within the hollow
cylindrical volume and comprising a rotatable head having fluid
outlet means arranged to provide at least one eccentrically
directed generally outwardly radially extending stream and means
for restricting the stream to predefined azimuthal limits.
[0048] In accordance with a preferred embodiment of the embodiment,
the fluid outlet means comprises at least one nozzle and curved
engagement means surrounding the at least one nozzle for engagement
with the downstream cylindrical surface.
[0049] Additionally in accordance with a preferred embodiment of
the invention, there is provided a backflushing nozzle for use in
backflushing a filter and comprising a rotating head having first
and second liquid outlets, the first outlet arranged to provide a
radially extending stream and the second outlet arranged to provide
a tangentially directed stream for providing rotational motion of
the rotating head.
[0050] Additionally in accordance with an embodiment of the
invention, there is provided a backflushing nozzle for use in
backflushing a filter and comprising a head defining a tapered
protrusion and a liquid outlet disposed at the protrusion, whereby
the head is arranged such that the protrusion sequentially engages
and spreads folds of filter material while the liquid outlet
provides a pressurized spray at the spread folds.
[0051] An object of the present invention is to provide a
multiple-disk-filter having a capacity for removing and retaining
large quantities of solid particles from the fluid before cleaning
of the filter is required.
[0052] According to a broad aspect of the present invention, there
is provided a filter including a housing having an inlet
connectable to an upstream pipe, and an outlet connectable to a
downstream pipe; and a stack or disks disposed within said housing
for separating solid particles from a fluid flowing between said
disks from the upstream side of said stack to the downstream side
thereof; characterized in that the stack includes: a plurality of
filter disks having a large surface area of their side faces formed
with grooves; and a spacer member interposed between each pair of
adjacent filter disks; the spacer members having surfaces
contacting only a portion of the grooved faces of the filter disks
leaving a portion of the grooved faces of the filter disks on the
upstream side of the stack not contacted by the spacer members, to
thereby form; (a) compartments on the upstream side of the stack
for accumulation of solid particles which settle in the grooves;
(b) edge filtering passageways along the upstream edges of the
spacer members in contact with the grooved faces of the filter
disks, which passageways define the size of particles separated by
the filter; and (c) further filtering passageways of large surface
area in the compartments, the latter passageways extending between
the particles settling in the grooves in the compartments, and
through the grooves to the downstream side of the stack.
[0053] A filter constructed in accordance with the foregoing
features has been found to have a large capacity for removing and
retaining solid particles before cleaning of the filter is required
because of undue clogging by the removed particles.
[0054] There is provided in accordance with a preferred embodiment
of the present invention, a disk-type filter including a housing
having an inlet connectable to an upstream pipe, and an outlet
connectable to a downstream pipe; and a stack of filter elements
disposed within the housing for separating solid particles from a
fluid flowing between the filter elements from an upstream side of
the stack to a downstream side thereof; characterized in that the
stack includes a plurality of cooperating filter elements defining
a plurality of paired cooperating filter surfaces, including a
first surface defining an array of grooves, extending in a first
orientation and a second surface defining an undulating strip
defining an array of grooves facing the array of grooves of the
first surface and extending in a second orientation, skewed with
respect to the first orientation, one side of the undulating strip
communicating with the upstream side and the other side of the
undulating strip communicating with the downstream side.
[0055] In accordance with a preferred embodiment of the present
invention, the undulating strip is configured to define a plurality
of generally radially extending fingers each having formed thereon
a pair of spaced, generally raised line portions separated by an
interior area, the raised line portions defining a plurality of
spaced grooves facing the plurality of grooves of the first surface
and extending in a second orientation, skewed with respect to the
first orientation, the exterior of the fingers communicating with
either one of the upstream side or the downstream side and the
interiors of the fingers communicating with the other one of the
upstream side or the downstream side.
[0056] In accordance with a preferred embodiment of the invention
the first surface defines a continuous surface and the first
orientation is a circumferentially extending orientation.
[0057] In accordance with another preferred embodiment of the
invention the first surface defines a plurality of generally
radially extending fingers arranged in registration with the
fingers of the second surface, whereby the raised line portions and
grooves of the first and second surfaces extend in overlapping
mutually-skewed orientations.
[0058] Additionally in accordance with the invention, the raised
line portions and grooves of the first and second surfaces define
multiple branched paths for traversal of fluid from the upstream
side to the downstream side.
[0059] Further in accordance with a preferred embodiment of the
invention, a filter aid, such as diatomaceous earth or activated
carbon is disposed upstream of the engaged first and second
surfaces.
[0060] In accordance with a preferred embodiment of the present
invention, the upstream facing edge of the second surface defines a
filtering barrier between the upstream side and the downstream
side. Further in accordance with an embodiment of the invention,
the engaging mutually skewed groove arrays of the first and second
surfaces define an enhanced length filtering pathway.
[0061] Additionally in accordance with a preferred embodiment of
the present invention, the thickness of the raised line portion on
the second surface, is less than the separation between adjacent
line portions. Preferably, the thickness of the raised line portion
on the second surface is approximately one half or less than the
separation between adjacent line portions, thus enabling a
relatively high density of filtering barrier to be defined on a
given area of filter element.
[0062] Further in accordance with an embodiment of the invention,
the raised line portion is of generally uniform thickness, thus
providing a filtering barrier of generally uniform
characteristics.
[0063] In accordance with a preferred embodiment of the invention,
the raised line portion on the second surface is continuous along
the entire second surface and defines a closed loop.
[0064] Further in accordance with a preferred embodiment of the
present invention, the undulating strip is configured in the form
of curved fingers, thus producing an overall strip of enhanced
length to filter element surface area ratio.
[0065] In accordance with one preferred embodiment of the present
invention the stack of filter elements comprises first and second
filter element types, the first filter element type being formed
with first filter surfaces on both of its planar surfaces and the
second filter element type being formed with second filter surfaces
on both of its planar surfaces.
[0066] In accordance with this preferred embodiment, the radially
extending raised line portions on the two second surfaces of the
second filter element type defining the fingers are preferably
displaced in respective out of phase relationship. This arrangement
provides enhanced structural strength of the second filter element
type and obviates the requirement for a predetermined relative
azimuthal arrangement of filter elements in a stack.
[0067] Further in accordance with a preferred embodiment of the
present invention, the stack of filter elements comprises a
generally cylindrical element having an axial central bore along
its longitudinal axis which defines the downstream side.
[0068] Additionally in accordance with this embodiment of the
invention, the apparatus for providing comprises a fluid discharge
device arranged for axial movement along the bore in communication
with the downstream side.
[0069] Further in accordance with an embodiment of the invention,
the fluid discharge device comprises fluid driven means for
providing rotation of the relatively high pressure flow about the
longitudinal axis.
[0070] Additionally in accordance with an embodiment of the
invention, the fluid discharge device is manually manipulable for
providing the axial movement along the bore.
[0071] Further in accordance with an embodiment of the invention,
the discharge device in normally seated within the bore.
[0072] Additionally in accordance with an embodiment of the
invention, the discharge device is provided with valve means which
seal the discharge device when it is fully seated within the
bore.
[0073] Further in accordance with an embodiment of the invention,
the filter apparatus comprises a manually operable multi-flow valve
having a normal position wherein fluid to be filtered is coupled to
the upstream side of the stack of filter elements and a backflush
position wherein fluid to be filtered is prevented from reaching
the upstream side of the stack of filter elements and is directed
to the means for providing a pressurized flow and wherein a
backflush drain communicating with the upstream side of the stack
of filter elements is coupled for draining to the atmosphere.
BRIEF DESCRIPTION OF THE DRAWINGS
[0074] The present invention will be understood and appreciated
more fully from the following detailed description taken in
conjunction with the drawings in which:
[0075] FIG. 1 is a partially cut-away side view sectional
illustration of a filter constructed and operative in accordance
with an embodiment of the present invention in a first operative
orientation;
[0076] FIG. 2 is a partially cut-away side view sectional
illustration of the filter of FIG. 1 in a second operative
orientation;
[0077] FIG. 3 is a partially cut-away side view sectional
illustration of a filter constructed and operative in accordance
with an alternative embodiment of the present invention;
[0078] FIG. 4 is a partially cut-away top view sectional
illustration of the filter of FIG. 3, showing the structure of
valve apparatus forming part thereof in a first operative
orientation;
[0079] FIG. 5 is a partially cut-away side view sectional
illustration of the filter of FIG. 3, showing the structure of
valve apparatus forming part thereof in a second operative
orientation;
[0080] FIGS. 6A and 6B are respective side view sectional
illustrations of the valve apparatus of the valve of FIGS. 3-5 in
respective first and second operative orientations.
[0081] FIG. 7 is a pictorial illustration of a portion of a stack
of filter disks constructed and operative in accordance with a
preferred embodiment of the invention;
[0082] FIG. 8 is an enlarged illustration of a portion of the stack
of filter disks illustrated in FIG. 7;
[0083] FIG. 9 is a plan view illustration or a surface of one of
the filter disks constructed and operative in accordance with a
preferred embodiment of the present invention;
[0084] FIG. 10 is a side sectional view of filter apparatus
constructed and operative in accordance with a preferred embodiment
of the present invention;
[0085] FIG. 11 is a sectional illustration taken along the lines
XI-XI of FIG. 10;
[0086] FIG. 12 is an enlarged illustration of part of the filter
apparatus of FIG. 10 in a somewhat different operating orientation
from that illustrated in FIG. 10;
[0087] FIG. 13 is a side sectional view of an alternative
embodiment of filter apparatus constructed and operative in
accordance with the present invention;
[0088] FIG. 14 is a side view sectional illustration of part of the
filter apparatus of FIG. 10, taken at 90 degrees to the plane of
FIG. 10;
[0089] FIG. 15 is a sectional illustration of the filter apparatus
of FIG. 14 taken along the lines XV-XV;
[0090] FIG. 16 is a side view sectional illustration of a further
alternative embodiment of filter apparatus constructed and
operative in accordance with the present invention;
[0091] FIG. 17 is a pictorial illustration of fluid discharge
apparatus useful in various embodiments of the invention seen along
lines A-A of FIG. 16;
[0092] FIG. 18 is an illustration of two disconnected portions of a
still further alternative embodiment of filter apparatus
constructed and operative in accordance with the present
invention;
[0093] FIG. 19 is a pictorial illustration of a portion of a stack
of filter disks constructed and operative in accordance with a
preferred embodiment of the invention;
[0094] FIG. 20 is an enlarged illustration of a portion of the
stack of filter disks illustrated in FIG. 19;
[0095] FIG. 21 is a sectional illustration taken along the lines
XXI-XXI of FIG. 20;
[0096] FIG. 22 is a plan view illustration of a disk of porous
material forming part of the stack of FIG. 20;
[0097] FIG. 23 is a plan view illustration of a transparent spacer
disk showing the overlapped arrangement of the grooves formed on
opposite sides thereof;
[0098] FIG. 24 is a pictorial illustration of a stack of filter
disks of the type shown in FIGS. 19-23;
[0099] FIG. 25 is an illustration of a portion of a stack of filter
disks constructed and operative in accordance with another
preferred embodiment of the invention;
[0100] FIG. 26 is a sectional illustration taken along the lines
XXVI-XXVI in FIG. 25;
[0101] FIG. 27 is an enlarged sectional illustration of the stack
of filter disks shown in FIGS. 25 and 26 showing the direction of
fluid flow during normal filtering operation;
[0102] FIG. 28 is an enlarged sectional illustration of the stack
of filter disks shown in FIGS. 25 and 26 showing the direction of
fluid flow during backflushing operation;
[0103] FIG. 29 is a partially cut-away side view sectional
illustration of a filter constructed and operative in accordance
with an embodiment of the present invention;
[0104] FIG. 30 is a sectional illustration taken along the lines
XXX-XXX of FIG. 29;
[0105] FIG. 31 is a sectional illustration taken along the lines
XXXI-XXXI of FIG. 29;
[0106] FIG. 32 is a partially cut-away side view sectional
illustration of a filter constructed and operative in accordance
with an alternative embodiment of the present invention;
[0107] FIG. 33 is a sectional illustration taken along the lines
XXXIII-XXXIII of FIG. 32;
[0108] FIG. 34 is a sectional illustration corresponding to that of
FIG. 33 but illustrating a dual nozzle variety of filter otherwise
similar to the single-nozzle variety shown in FIGS. 32 and 33;
[0109] FIG. 35 is a sectional illustration taken along the lines
XXXV-XXXV of FIG. 33;
[0110] FIG. 36 is a sectional illustration taken along the lines
XXXVI-XXXVI of FIG. 34;
[0111] FIG. 37 is a partially cut-away side view sectional
illustration of a filter constructed and operative in accordance
with a further alternative embodiment of the present invention;
[0112] FIG. 38 is a sectional illustration taken along the lines
XXXVIII-XXXVIII of FIG. 37;
[0113] FIG. 39 is a sectional illustration corresponding to that of
FIG. 38 but illustrating another variety of dual-nozzle filter
otherwise similar to the variety shown in FIGS. 32 and 33;
[0114] FIG. 40 is a sectional illustration corresponding to that of
FIG. 37 but illustrating a single-nozzle variety of filter
otherwise similar to the dual-nozzle variety of filter otherwise
similar to the dual-nozzle variety shown in FIGS. 37-39;
[0115] FIG. 41 is a sectional illustration taken along the lines
XLI-XLI of FIG. 40;
[0116] FIGS. 42A, 42B, 42C illustrate three alternative
configurations of dual-nozzle outlet means;
[0117] FIG. 43 is a pictorial illustration of a portion of a stack
of filter elements constructed and operative in accordance with a
preferred embodiment of the Invention;
[0118] FIG. 44 is a pictorial illustration of a portion of a stack
of filter elements shown in FIG. 43, also showing the accumulation
of sediment thereon;
[0119] FIG. 45 is an enlarged illustration of a portion of the
stack of filter elements illustrated in FIG. 43;
[0120] FIG. 46 is an enlarged illustration of a portion of the
stack of filter elements illustrated in FIG. 44 also showing the
accumulation of sediment thereof;
[0121] FIG. 47 is a further enlarged illustration of a portion of
the stack of filter elements illustrated in FIG. 44 also showing
the accumulation of sediment thereon;
[0122] FIG. 48 is a pictorial illustration of the curved
configuration of one of the stack of filter elements shown in FIG.
43;
[0123] FIGS. 49A and 49B are sectional illustrations taken along
the lines A-A and B-B respectively of FIG. 48;
[0124] FIG. 49C is a superimposed illustration showing the relative
orientations of opposite sides of a filter element of the type
illustrated in FIG. 48;
[0125] FIG. 50 is a pictorial illustration of a portion of a stack
of filter elements constructed and operative in accordance with
another preferred embodiment of the invention;
[0126] FIG. 51 is a pictorial illustration of a portion of a stack
of filter elements of FIG. 50 also showing the accumulation of
sediment thereon;
[0127] FIG. 52 is an enlarged illustration of a portion of the
stack of filter elements illustrated in FIG. 50;
[0128] FIG. 53 is an enlarged illustration of a portion of the
stack of filter elements illustrated in FIG. 51, also showing the
accumulation of sediment thereon; and
[0129] FIG. 54 is a further enlarged illustration of a portion of
the stack of filter elements illustrated in FIG. 53 also showing
the accumulation of sediment thereon.
DETAILED DESCRIPTION OF THE DRAWINGS
[0130] Reference is now made to FIG. 1 which illustrates a filter
constructed and operative in accordance with a preferred embodiment
of the present invention and comprising a base 1010 on which is
fixedly supported a bottom housing portion 1012. Removably mounted
onto the bottom housing portion 1012 is a top housing portion 1014,
which is maintained in sealing engagement therewith by means of a
sealing ring 1016. The bottom housing portion 1012 typically
comprises an inlet opening 1013 and an outlet opening 1015.
[0131] A fluid inlet 1018 is provided at inlet opening 1013 and
communicates with the outside cylindrical surface, hereinafter
termed the "upstream surface" of a filter element 1019. A fluid
outlet 1020 is defined at outlet opening 1015 and communicates with
a hollow interior volume 1021 of filter element 1019 adjacent the
inner cylindrical surface of the filter element, hereinafter termed
the "downstream surface".
[0132] The filter element 1019 preferably comprises a stack of
hollow center filter disks 1022 of any suitable type.
Alternatively, the filter element may comprise any other suitable
type of filter element such as a cartridge or cylindrical mesh
filter. Suitable filter disks are described in the U.S. Patents
listed hereinabove in the "Background of the Invention," and are
operative to remove particulate matter from liquids passing
therethrough from the upstream surface to the downstream surface. A
preferred filter disk arrangement is described and claimed in
co-pending Israel Patent Application 78160, filed Mar. 14, 1986,
the disclosure of which is incorporated herein by reference.
[0133] The stack of filter disks 1022 is preferably removably
mounted in coaxial relationship so as to define volume 1021 and is
retained within the housing by means of top and bottom retaining
collars 1024 and 1026. A plurality of threaded rods 1028, typically
four in number, secure the stack of filter disks 1022 in place. A
cover retaining nut 1034 serves to retain cover portion 1014 onto
the bottom portion 1012.
[0134] It is noted that throughout the present specification and
claims reference is made to fluid filtering. According to a
preferred embodiment of the invention, the apparatus is adapted for
filtering of liquids, however, it is also alternatively applicable
for filtering of other fluids, such as gases.
[0135] A high pressure revolving spray nozzle assembly 1040 is
disposed mainly within volume 1021 and comprises a water supply
shaft 1050 having a water inlet 1051 and an associated inlet valve
1053. A fixed base portion 1054 is typically mounted onto shaft
1050 and serves to maintain the nozzle assembly 1040 centered with
respect to volume 1021 and the downstream cylindrical surface of
filter element 1019. Base portion 1054 is typically formed in an
apertured manner to permit liquid flow therepast through volume
1021.
[0136] A rotating outlet head 1056 is arranged for relatively free
rotation about a rotation axis 1060 defined in shaft 1050 and is
preferably provided with first and second output apertures 1057 and
1058.
[0137] Outlet aperture 1057, which is the primary outlet aperture,
is typically arranged to provide a radially directed concentrated
high pressure backflushing jet, which serves to flush particulate
matter from the filter element 1019. Outlet aperture 1058 is
arranged to provide a tangentially directed stream, which produces
rotation of head 1056 about axis 1060.
[0138] Inlet 1051 is typically coupled via a flexible hose 1084 to
a backflush liquid supply which may be connected to a pressurized
source of liquid to be filtered.
[0139] According to a preferred embodiment of the present
invention, there is associated with inlet 1018 a one way pressure
or flow responsive valve 1062 typically comprising a stem 1064,
which is slidably mounted on an apertured stem support 1066 and is
urged toward a closed orientation typically by means of a spring
1068. Spring 1068 is typically seated between a spring seat 1070
mounted onto one end of stem 1064 and the apertured stem support
1066.
[0140] The end of stem 1064, opposite from that associated with
spring seat 1070, is formed as a deflector 1072 and has a
peripheral sealing surface 1074 which sealingly engages a rim 1076
of valve 1062, when the valve is closed. FIG. 1 illustrates the
valve 1062 in an open orientation, when fluid, such as water, is
flowing under pressure from a fluid source (not shown) to the
interior of the housing, as during normal filtering operation. It
is a particular feature of the present invention that deflector
1072 serves to deflect the incoming fluid, when the valve 1062 is
open, so that it does not impinge directly onto the facing portion
of the upstream surface of filter element 1019, thus forcing dirt
thereinto. It is also a particular feature of deflector 1072 that
it provides a directionally uniform distribution of the deflected
fluid thereabout.
[0141] FIG. 2 illustrates the valve 1062 in a closed orientation,
as during backflushing, when the pressure gradient between the
inlet and the interior of the housing is opposite to that which is
obtained during normal filtering, or is zero.
[0142] It is appreciated that valve 1062 is operative to prevent
backflow of fluid into the inlet during backflushing, by
automatically closing whenever the pressurized flow of water into
the housing for normal filtering is terminated.
[0143] A manually operable one way valve 1080 is operative to
provide selectable drainage from the interior of the housing
communicating with the upstream surface of the filter element, in
communication with a backflush drain outlet 1082.
[0144] During normal operation of the filter of the present
invention, assembly 1040 is located mainly within volume 1021 and
shaft 1050 is sealingly coupled to the top portion 1014 of the
housing by means of a sealing collar 1086 which sealingly engages
threading on shaft 1050 and on the top portion 1014. Valve 1062 is
operated by the pressure of the incoming liquid to assume an open
orientation as shown in FIG. 1, permitting the incoming liquid to
come into filtering engagement with the filter element 1019. Valve
1080 is oriented as shown in FIG. 1 such that liquid to be filtered
is not drained therethrough. The incoming liquid passes through the
filter element 1019 from the upstream surface to the downstream
surface, being filtered in the process. The filtered liquid passes
through volume 1021 and outlet 1020. Valve 1053 is closed.
[0145] During backflush operation, the pressurized liquid source is
decoupled from inlet 1018 and valve 1080 is opened, as seen in FIG.
2. Valve 1053 is opened to provide a pressurized flow of water to
assembly 1040, collar 1086 is disconnected.
[0146] High pressure spray outlet head 1056 is manually
reciprocated axially along the interior of the filter element at
the downstream surface, causing a high pressure concentrated jet of
water to impinge on the downstream surface thereof for dislodging
accumulated filtered material from the filter element. This
arrangement enables substantially the entire downstream surface to
be thus scanned, region by region, by the high pressure
concentrated jet for efficient backflush cleaning of the filter
element.
[0147] Reference is now made to FIGS. 3-6B, which illustrate an
alternative preferred embodiment of the invention. The filter shown
in FIGS. 3-6B may be identical to that described hereinabove in
connection with FIGS. 1 and 2 except as specifically explained
hereinbelow. The common elements of the two embodiments are
indicated by the same reference numerals.
[0148] In accordance with a preferred embodiment of the invention,
illustrated in FIGS. 3-6B, a two-position fluid pressure controlled
valve is provided for governing both inlet of fluid to be filtered
to the upstream side of the filter element 1019 during normal
filtering operation and drainage of backflushing drain fluid from
the upstream side of the filter element 1019 during backflushing
operation.
[0149] A conduit 1100 communicates with the interior of the filter
housing at the upstream side of the filter element via a
communication port 1102 and also defines an inlet opening 1104 for
receiving fluid to be filtered and an outlet opening 1106 for
drainage of backflushing liquid. Associated with respective
openings 1104 and 1106 are respective inlet and outlet connection
couplings 1108 and 1110, each of which defines a generally
cylindrical inwardly directed inner surface 1112 which is formed to
define an apertured stem mounting 1114. Couplings 1108 and 1110
also define respective inwardly directed rims 1115 and 1117.
[0150] A valve stem 1116 is slidingly mounted onto stem mountings
1114 and comprises a rod 1118 which is fixedly attached to or
integrally formed with a sealing cap 1120, formed with a pair of
peripheral sealing surfaces 1122, typically formed of rubber, on
opposite sides thereof. A spring 1124, seated between a spring seat
1126 formed on one side of rod 1118 and the adjacent stem mounting
1114, urges the valve stem 1116 into a second operative
orientation, wherein the cap 1120 lies in sealing engagement with
rim 1115. This orientation is illustrated in FIG. 6B.
[0151] During normal filtering operation, fluid to be filtered is
supplied under sufficient pressure as to overcome the urging of
spring 1124 and to force cap 1120 into sealing engagement with rim
1117, as shown in FIG. 6A. In this operative engagement, the fluid
to be filtered enters the upstream side of the filter housing, and
the backflush drain is blocked.
[0152] During backflushing, when the incoming fluid is cut off by
suitable means, such as a cut-off valve (not shown), or by
termination of the operation of a pump 1081, the spring 1124 causes
cap 1120 to return into sealing engagement with rim 1115, thus
providing drainage of backflushed fluid from the upstream side of
the filter element 1019 (FIG. 3).
[0153] Reference is now made to FIGS. 11-15, which illustrate a
stack of filter disks constructed and operative in accordance with
a preferred embodiment of the invention. The stack of filter disks
is suitable for use in any suitable filter apparatus, examples of
which are described in the patents and patent applications listed
hereinabove.
[0154] The assembly shown in FIGS. 7-9 comprises alternating
centrally apertured disks 2010 formed of a plastic material, such
as polypropylene. The disks are of two types, filter disks 2012 and
accumulator disks 2014. The filter disks 2012 are typically formed
with identical first planar surfaces defining circumferential
grooves 2016, typically having a generally V-shaped cross section.
Intermediate the grooves are defined raised line portions 2018
which also extend circumferentially. Both the grooves and the line
portions typically lie in a circular concentric pattern.
[0155] The accumulator disks 2014 typically comprise identically
patterned opposite second planar surfaces, wherein the patterns are
somewhat out of phase with each other, typically by one half the
spacing therebetween. This out of phase arrangement provides
enhanced structural strength to the accumulator disk 2014 and
enables it to be made of relatively thin material.
[0156] Each planar surface of accumulator disk 2014 is formed with
an accumulator barrier defined by a raised line pattern 2020, which
is arranged to extended continuously in generally undulating
configuration defining a plurality of radially extending finger
elements 2022 on the face of the planar surface. The raised line
pattern 2020 typically defines the outline of each finger element
2022 and is arranged to define a notched or serrated pattern along
the radially extending portion of each finger.
[0157] When the first and second planar surfaces are arranged in
juxtaposed engagement, the raised line pattern 2020 engages the
raised line portions 2018 on the filter disks, defining a filter
barrier between the upstream side of the filter and the downstream
side. Liquid passes through the narrow openings defined between
raised line pattern 2020 and the grooves 2016. Particles larger
than these openings cannot pass the barrier.
[0158] It is a particular feature of the present invention that the
notched or serrated pattern of the raised line pattern 2020
provides a relatively long filter barrier across which filtration
occurs, when the second planar surface is located in juxtaposed
engagement with the first planar surface. The relatively high ratio
of filter barrier to planar surface area produced by this
configuration provides a high filtering efficiency per unit size of
the filter.
[0159] It is a further particular feature of the present invention
that the raised line pattern is relatively thin so as to enable a
high density of line patterns to be provided per unit area of the
planar surface.
[0160] In the illustrated preferred embodiment, the spacer disk
2014 has an inner diameter of 9 cm and an outer diameter of 16 cm,
and thus a total surface area of 137.445 cm.sup.2. In this
embodiment a filter barrier of overall length 662.35 cm is provided
thus providing a ratio of filter barrier length to disk area of
4.82. The thickness of the raised line pattern 2020 is typically
0.75 mm and the minimum separation between adjacent filter barrier
portions is typically 1.2 mm.
[0161] It is a particular feature of the present invention that the
upstream facing edge of the filter barrier is disposed along nearly
all of its length at an angle other than 90 degrees with respect to
grooves 2016. As a result, the area subtended by the sides of the
groove 2016 and the barrier, illustrated at reference numeral 2030,
is larger than the area that would be subtended had the angle been
90 degrees. Such an area is indicated at reference numeral 2032. It
is seen that, not withstanding the fact that area 2030 is larger
than area 2032, it does not follow that a larger particle will be
allowed to pass through area 2030, since such a particle is still
limited by the constant width of groove 2016.
[0162] Reference is now made to FIGS. 10-12, which illustrate
filter apparatus constructed and operative in accordance with a
preferred embodiment of the invention. The filter apparatus
comprises a body, generally indicated by reference numeral 3010.
The body is typically formed of two separate parts, a connection
portion 3012, and a filter element housing 3014. The two parts are
typically separable by a user, but need not be so.
[0163] The connection portion 3012 defines an inlet 3016, which is
coupled to a supply of fluid to be filtered, and typically is
formed with an inner threading 3018. Inlet 3016 is preferably also
provided with an inlet bypass connector 3020, whose purpose and
function will be described hereinafter. Downstream of inlet 3016
there is provided a manually actuable valve 3022.
[0164] Valve 3022 is provided with a handle 3024, a valve seat
3026, which is preferably integrally formed with the connection
portion 3012, and a valve stem 3028, which is coupled for rotation
together with handle 3024 with respect to valve seat 3026.
According to a preferred embodiment of the invention illustrated
here, valve 3022 comprises a ball or cylinder valve and is best
seen from consideration of additional FIGS. 14 and 15.
[0165] As seen particularly in FIGS. 14 and 15, stem 3028 is
typically of spherical configuration and is formed with a
throughgoing bore 3030. It will be appreciated that stem 3028 may
be rotated by handle 3024 to assume a selected one of two operating
positions. In a first operating position, illustrated in FIG. 12,
the bore 3030 is positioned to permit direct fluid communication
from the inlet 3016 to an interior portion 3032 of the connection
portion 3012.
[0166] In an alternative operating position, illustrated in FIGS.
10, 14 and 15, the bore 3030 is at 90 degrees to its position shown
in FIG. 12 and blocks fluid communication between inlet 3016 and
the interior portion 3032. In this operating position, the bore
3030 provides fluid communication between two fluid connectors 3034
and 3036, whose purpose and function will be described
hereinbelow.
[0167] Interior portion 3032 communicates with the interior of
filter element housing 3014, and more specifically with the outer
surface 3037 of a filter element 3038 which is located within
housing 3014. The outer surface of filter element 3038 will
henceforth be termed the upstream surface thereof. An inner surface
3039 of the filter element 3038 will henceforth be termed the
downstream surface thereof. It is appreciated that these
designations may be reversed for a different flow arrangement
through the filter apparatus.
[0168] Filter element 3038 preferably but not necessarily comprises
a stack of filter disks 3040 which are held together tightly by
ring element 3046 which is fixed by a snap connection within
housing 3041 between disks 3040 and end element 3042. End element
3042 is an integral part of housing element 3014 and presses around
ring element 3046 so as to hold the filter disks tightly against
each other for high performance filtering of relatively small
particles.
[0169] Filter disks 3040 may be constructed to have any suitable
configuration. Examples of suitable configurations are provided in
applicant's pending U.S. patent application Ser. No. 709.372.
[0170] A preferred configuration of filter element is illustrated
in FIGS. 19-24, to which reference is now made. The assembly shown
in these figures comprises alternating centrally apertured disks
3040 of a porous material, such as polyester cartridge or
polypropylene cartridge or any type of mesh. Disks 3040 may be of
any preferred thickness or other characteristics so as to provide
any desired fineness of filtration.
[0171] It is specifically noted that disks 3040 may be formed of
porous material of any desired characteristics and pass through
specifications and that the term "porous material" as used herein,
also includes screen material of any suitable mesh size. It also
includes single or multiple layer porous material with uniform or
different pass through characteristics.
[0172] Intermediate disks 3040 there are provided spacer disks 3044
which define axially tapered generally radially extending grooves.
It is a particular feature of the present invention that the
generally radially extending grooves are normally not all precisely
radial, for reasons which will now be described.
[0173] Specifically considering spacer disks 3044, it is seen that
the disks 3044 define two opposite grooved surfaces, which will be
termed, for convenience, surfaces 3048 and 3049. Surface 3048 is
formed with tapered generally radially extending upstanding
portions 3050 which are highest at the inner edge 3052 of the
spacer disk and taper to a minimum adjacent a raised peripheral
portion 3054 lying alongside the outer edge 3056 of the spacer
disk.
[0174] Surface 3049 is formed with tapered generally radially
extending upstanding portions 3060 which are highest at the outer
edge 3056 of the spacer disk and taper to a minimum adjacent a
raised peripheral portion 3064 lying alongside the inner edge 3052
of the spacer disk.
[0175] In order to provide maximum structural strength to spacer
disk 3044, it is preferred but not essential that the upstanding
portions 3050 and 3060 which overlie each other are somewhat skewed
with respect to each other, such that upstanding portion 3050
diagonally overlies upstanding portion 3060. This arrangement
enables the thickness of the planar portion 3066 of the spacer disk
3044 to be made very thin. In this arrangement, one or both of the
upstanding portions 3050 and 3060 are non-radial. Nevertheless, in
view of their generally radial orientation, such an arrangement is
being defined throughout as providing generally radially extending
grooves.
[0176] In the preferred embodiment of the invention in which the
upstanding portions 3050 and 3060 are skewed, it is preferable that
their relative angular orientation be such that the groove or
channel 3065 defined between each pair of upstanding portions 3050
partially overlaps and crosses at least two and preferably three
such grooves or channels 3067. This structure is shown in FIG. 23
which illustrates a transparent spacer disk, it being understood
that the transparent spacer disk is illustrated herein only for
purposes of clarity of illustration and explanation and that
normally, non-transparent spacer disks are used.
[0177] The structure wherein each groove or channel 3065 partially
overlaps and crosses at least two and preferably three such grooves
or channels 3067 has a number of advantages. Liquid to be filtered
typically enters a channel 3067 at the outer edge of the filter
element. Channel 3067 tapers down to a closed end against raised
peripheral portion 3064. Therefore all of the liquid must pass
through the adjacent porous material of disk 3040.
[0178] The liquid can pass through the porous material of disk 3040
at any location along the channel 3067 and thus, when it exits the
opposite side of adjacent disk 3040, it may then travel in any one
of channels 3065 which lead to the interior of the filter element.
Which of the channels 3065 carries the liquid is dependent upon the
location at which the liquid leaves disk 3040. Thus if one or more
of the channels 3065 becomes blocked or clogged for any reason, the
liquid can pass along one or more alternative channels.
[0179] Similarly, during backflushing operation, a backflush fluid
typically enters a channel 3065 at the inner edge of the filter
element. Channel 3065 tapers down to a closed end against raised
peripheral portion 3054. Therefore all of the liquid must pass
through the adjacent porous material of disk 3040.
[0180] The liquid can pass through the porous material of disk 3040
at any location along the channel 3065 and thus, when it exits the
opposite side of adjacent disk 3040, it may then travel in any one
of channels 3067 which lead to the exterior of the filter element.
Which of the channels 3067 carries the liquid is dependent on the
location at which the liquid leaves disk 3040. Thus if one or more
of the channels 3067 becomes blocked or clogged for any reason the
liquid can pass along one or more alternative channels.
[0181] FIG. 21 illustrates the arrangement of a portion of a stack
of filter disks as described hereinabove. It is seen that the
arrangement is symmetric with respect to upstream and downstream
surfaces of a filter element constituted from a stack or such
filter disks, in that both surfaces are defined by an array of
tapered grooves which serve to collect dirt upstream of the porous
disk 3040.
[0182] Another preferred configuration of a filter element is
illustrated in FIGS. 25-28, to which reference is now made. The
assembly shown in these figures comprises alternating centrally
apertured disks 3240 of a porous material, such as polyester
cartridge or polypropylene cartridge or any type of mesh. Disks
3240 may be of any preferred thickness or other characteristics so
as to provide any desired fineness of filtration and may be similar
in all relevant respects to disks 3040 described above.
[0183] Intermediate disks 3240 there are provided spacer disks 3244
which define axially tapered generally radially extending
grooves.
[0184] Specifically considering spacer disks 3244, it is seen that
the disks 3244 define two opposite grooved surfaces, which will be
termed, for convenience, surfaces 3248 and 3249. Surface 3248 is
formed with tapered generally radially extending upstanding
portions 3250 which are highest with respect to the disk surface
3251 at the inner edge 3252 of the spacer disk and terminate in a
peripheral rim 3253 along the inner edge of the spacer disk, at the
same height as the adjacent portions of the upstanding portions
3250.
[0185] The upstanding portions 3250 taper to a minimum, adjacent a
raised peripheral rim portion 3254, of height equal to the height
of the adjacent upstanding portions. Rim portion 3254 lies adjacent
but spaced from the outer edge 3255 of the spacer disk by a
plurality of spacer rib portions 3256 which in fact define portions
of upstanding portions associated with disk surface 3249.
[0186] Surface 3249 is formed with tapered generally radially
extending upstanding portions 3260 which are highest at the outer
edge 3255 of the spacer disk and terminate in an outer peripheral
rim 3257, which lies at the same height as the upstanding portions
3260 adjacent thereto. Upstanding portions 3260 taper to a minimum
adjacent a rim 3262 which lies adjacent to but spaced from the
inner edge 3252 of the spacer disk.
[0187] It may be appreciated that rims 3253 and 3262 lie in
adjacent. non-overlapping relationship on opposite sides of the
spacer disk, rim 3262 being located radially inward with respect to
rim 3253. Similarly rims 3254 and 3257 lie in adjacent,
non-overlapping relationship on opposite sides of the spacer disk,
rim 3254 being located radially inward with respect to rim
3257.
[0188] The above described structure of rims 3253, 3254, 2357, and
3262 provides extremely high quality sealing between the spacer
disks 3244 and the porous material disks 3240, while defining clear
openings for both filtration and backflushing.
[0189] As described hereinabove in connection with FIGS. 20-24, it
is preferred but not essential that the upstanding portions 3250
and 3260 which overlie each other are somewhat skewed with respect
to each other, such that upstanding portion 3250 diagonally
overlies upstanding portion 3260. This portion 3251 of the spacer
disk 3244 to be made very thin. In this arrangement, one or both of
the upstanding portions 3250 and 3260 are non-radial. Nevertheless,
in view of their generally radial orientation, such an arrangement
is being defined throughout as providing generally radially
extending grooves.
[0190] In the preferred embodiment of the invention in which the
upstanding portions 3250 and 3260 are skewed, it is preferable that
their relative angular orientation be such that the groove or
channel 3265 defined between each pair of upstanding portions 3250
partially overlaps and crosses at least two and preferably three
such grooves or channels on the opposite side of the spacer disk as
shown in FIG. 23 for disks without the rims described
hereinabove.
[0191] Reference is now made to FIGS. 27 and 28 which illustrate
the fluid flows for normal filtering and backflushing respectively.
As seen in FIG. 27, a fluid such as a liquid to be filtered
typically enters a channel 3265 at the outer edge of the filter
element. Channel 3265 tapers down to a closed end against rim 3262.
Therefore all of the liquid must pass through the adjacent porous
material of disk 3240.
[0192] The liquid can pass through the porous material of disk 3240
at any location along the channel 3265 and thus, when it exits the
opposite side of adjacent disk 3240, it may then travel in any one
of channels 3266 which lead to the interior of the filter element.
Which channel carries the liquid is dependent upon the location at
which the liquid leaves channel 3265, which in turn is determined
by the state of clogging of each given channel. Thus if one or more
of the channels becomes blocked or clogged for any reason, the
liquid can pass along one or more alternative channels.
[0193] Similarly, during backflushing operation, as illustrated in
FIG. 28, a backflush fluid typically enters a channel 3266 at the
inner edge of the filter element. Channel 3266 tapers down to a
closed end against rim 3254. Therefore all of the liquid must pass
through the adjacent porous material of disk 3240.
[0194] Returning now to the connection portion 3012, as shown in
FIGS. 10 and 12, it is seen that there is defined a central volume
3070, which is separated from volume 3032 by a one way valve such
as pressure valve 3072, which is operative to permit fluid flow
from volume 3032 to volume 3070 only when the differential pressure
between volume 3032 and volume 3070 is sufficient to overcome the
biasing of pressure valve 3072. Pressure valve 3072 does not permit
fluid flow from volume 3070 to volume 3032 therethrough under any
circumstances.
[0195] Volume 3070 is separated from an outlet 3071 by means of a
second one-way valve such as check valve 3074, which is operative
to permit fluid flow from volume 3070 to outlet 3071 when the
differential pressure between volume 3070 and outlet 3071 is
sufficient to overcome the biasing of check valve 3074. Check valve
3074 does not permit fluid flow from volume 3070 to volume 3032
therethrough under any circumstances.
[0196] Slidably disposed within the body 3010 is a manually
operable flushing arm 3080. Flushing arm 3080 defines a fluid inlet
3082 which is coupled by a flexible conduit (not shown but
indicated by dashed lines) to the inlet by-pass connector 3020 for
receiving a pressurized flow of fluid from the inlet 3016.
[0197] Arm 3080 comprises a sealing collar 3084 which is arranged
to engage a corresponding fixed collar 3086 formed on the bottom
surface of filter element housing 3014. Typically sealing collar
3084 is formed of any desired elastic material. Arm 3080 also
comprises an elongate rigid tube 3088 at the end of which is
defined a discharge portion 3090.
[0198] The discharge portion 3090 may define a desired fluid
outlet. According to one embodiment, discharge portion 3090 may
provide a 360 degree outlet backflushing flow at relatively high
pressure, in engagement with the downstream surface 3039 of the
filter element. According to an alternative embodiment of the
invention, which will be described hereinbelow in connection with
FIG. 17, a rotatable directional flow may be provided.
[0199] In the embodiment discussed here, as shown in FIGS. 10 and
12, the discharge portion 3090 is provided with a sealing valve
arrangement 3092, which seals the discharge portion against fluid
communication in either direction, when the arm 3080 is fully
seated in the body 3010, i.e. when the valve 3092 is fully seated
against surface 3094 of the connection portion 3012.
[0200] A backflush drain 3096 is defined by element housing 3014 in
communication with the upstream surface of the filter element 3038
and is provided with a connector 3098, which is typically
connected, by a suitable conduit, not shown, but indicated in
dashed lines, to connector 3036 (FIG. 14). Connector 3034 may
typically be connected to a backflush drain, which is vented to the
atmosphere.
[0201] The operation of the apparatus of FIGS. 10-12, 14 and 15
will now be described briefly. During normal operation of the
filter, fluid, typically water to be filtered, enters at inlet 3016
and passes via valve 3022, in its first operating position shown in
FIG. 12, to volume 3032, wherein it impinges in a pressurized
manner on the filter element 3038 at its upstream surface 3037.
Dirt and other spurious matter filtered from the fluid are retained
within filter element 3038 and on the upstream surface thereof and
the filtered water exits the filter element at the downstream
surface which communicates with volume 3070 and from volume 3070
around check valve 3074 to the filtered water outlet 3071.
[0202] When it is sought to provide an extremely high volume, high
pressure flow of water, as for use in a spa or whirlpool bath,
pressure valve 3072 opens under pressure of the water, providing
bypassing of the filter and direct axial throughflow of the water
from the inlet 3016 to the outlet 3071.
[0203] When it is sought to clean the filter element, valve 3022 is
turned to its alternative operating position, as seen in FIG. 10,
thus blocking the flow of water from inlet 3016 to volume 3032.
Valve 3022 then interconnects connectors 3034 and 3036 (FIG. 15),
thus providing fluid communication from backflush drain 3096 to the
atmosphere.
[0204] Backflush arm 3080 may then be unseated from engagement with
surface 3094, thus causing opening of valve 3092 and providing a
relatively high pressure backflush flow of fluid received via
connector 3020 from the inlet 3016 in engagement with the
downstream surface 3039 of the filter element 3038. Reciprocal
displacement of the discharge portion 3090 along axis 3100,
provides flushing of the entire downstream surface of the filter
element 3038. The backflushed fluid together with the accumulated
dirt and other spurious material is drained through backflush drain
3096 to the atmosphere.
[0205] Reference is now made to FIG. 13, which illustrates an
alternative embodiment of filter apparatus, which represents a
simplification of the apparatus of FIG. 10. For the sake of
clarity, all elements of the apparatus which are similar in both
embodiments are labelled with the reference numerals employed
hereinabove. These elements are not described again here for the
sake of conciseness.
[0206] Briefly speaking, the apparatus of FIG. 13 eliminates the
use of valve 3022. Accordingly backflush arm 3080 is provided with
a manually actuable inlet valve 3102 which governs the supply of
backflushing fluid thereto from a pressurized source (not shown).
Similarly backflush drain 3096 is provided with an outlet valve
3104, which governs the outlet of backflush fluid therefrom. It is
also noted that the arm 3080 is arranged upside down in the
arrangement of FIG. 13 as compared with the arrangement of FIG. 10.
This is not considered to have any particular significance.
[0207] During normal filtering operation of the apparatus of FIG.
13, valves 3102 and 3104 are closed. They are both opened for
backflushing operation and the main water supply to the filter
inlet 3016 is closed.
[0208] Reference is now made to FIG. 16, which illustrates a
further alternative embodiment of the invention. The embodiment
includes both valves 3102 and 3401 as well as valve 3022. Here,
however, valve 3022 does not provide connections for the backflush
drain as in the embodiment of FIG. 10.
[0209] A further additional feature of the embodiment of FIG. 16 is
the provision of a rotating, directional backflush discharge head
3110, which is shown in plan view in FIG. 17. Head 3110 is
reciprocated along axis 3100 by the movement of arm 3080 and
provides eccentric, highly directional flows of backflushing fluid,
which cause rotation of the head in a direction indicated by arrow
3112 about axis 3100. This arrangement provides enhanced
backflushing operation because it employs a highly concentrated
flow, which "scans" each groove or cell defined in the filter
element with a flow, which is at higher pressure than a broader
flow, as provided by the discharge portion 3090 of the embodiment
of FIG. 10.
[0210] FIG. 18 illustrates a further alternative embodiment of the
invention, wherein the filter element housing portion 3014 is
removable from the remainder of the body for backflushing. A
separate backflushing arm 3120, typically of the type shown in
FIGS. 16 and 17 is coupled to a source of backflushing fluid (not
shown) and reciprocated along axis 3100 to backflush the filter
element. In this embodiment, where there is no need for inlet 3082
or backflush drain 3096, sealing the respective upstream and
downstream sides of the filter element with plugs 3122 and 3124
provides an inexpensive and double-purpose use of the same filter
element.
[0211] Reference is now made to FIGS. 29-31, which illustrate a
filter constructed and operative in accordance with a preferred
embodiment of the present invention and comprising a base 5010 on
which is fixedly supported a bottom housing portion 5012. Removably
mounted onto the bottom housing portion 5012 is a top housing
portion 5014, which is maintained in sealing engagement therewith
by means of a sealing ring 5016. The bottom housing portion 5012
typically comprises an inlet and outlet defining portion 5013,
which is typically molded integrally with base 5010, and a
cylindrical portion 5015, which may be extruded of a plastic
material, and may be sealingly joined to each other with the aid of
a sealing ring 5017.
[0212] A fluid inlet 5018 is formed at one side of defining portion
5013 and communicates with the outside cylindrical surface,
hereinafter termed the "upstream surface", of a stack of filter
elements 5019. A fluid outlet 5020 is defined at an opposite side
of defining portion 5013 and communicates with a hollow interior
portion 5021 of stack of filter elements 5019 adjacent the inner
cylindrical surface of the stack of filter elements, hereinafter
termed the "downstream surface".
[0213] The stack of filter elements 5019 preferably comprises a
stack of hollow center filter disks 5022 of any suitable type.
Alternatively, the stack of filter elements may be replaced by any
other suitable type of filter element such as a cartridge or
cylindrical mesh filter. Suitable filter disks are described in the
U.S. Patent Applications listed hereinabove in the "Background of
the Invention", and are operative to remove particulate matter from
liquids passing therethrough from the upstream surface to the
downstream surface. A preferred filter disk arrangement is
described and claimed in co-pending Israel Patent Application
78160, filed Mar. 14, 1986, the disclosure of which is incorporated
herein by reference.
[0214] The stack of filter elements 5022 is preferably removably
mounted in coaxial relationship so as to define volume 5021 and is
retained within the housing by means of top and bottom retaining
collars 5024 and 5026. A plurality of threaded rods 5028, typically
four in number, are anchored, as by suitable nuts 5030, in defining
portion 5013. Retaining collars 5024 and 5026 are mounted onto rods
5028 and retained by stack retaining nuts 5032. Cover retaining
nuts 5034 serve to retain top housing portion 5014 onto the bottom
housing portion 5012.
[0215] A high pressure revolving spray nozzle assembly 5040 is
disposed mainly within volume 5021 and comprises a water supply
shaft 5050 having a water inlet 5051 and an associated inlet valve
5053. A fixed base portion 5054 is typically mounted onto shaft
5050 and serves to maintain the nozzle assembly 5040 centered with
respect to volume 5021 and the downstream cylindrical surface of
stack of filter elements 5019. Base portion 5054 is typically
formed in an apertured manner to permit liquid flow therepast
through volume 5021.
[0216] A rotating outlet head 5056 is arranged for relatively free
rotation about a rotation axis 5060 defined in shaft 5050 and is
preferably provided with first and second output apertures 5057 and
5058.
[0217] Outlet aperture 5057, which is the primary outlet aperture,
is arranged to provide a radially directed concentrated high
pressure backflushing jet, which serves to flush particulate matter
from the stack of filter elements 5019. Outlet aperture 5058 is
arranged to provide a tangentially directed stream, which produces
rotation of head 5056 about axis 5060.
[0218] Inlet 5051 is typically coupled via a flexible hose 5052 to
a backflush liquid supply which may be connected to a pressurized
source of liquid to be filtered 5066. A two way valve 5067
selectably couples the water inlet 5018 of the filter either to
pressurized source 5066 or to backflush liquid drain 5063.
[0219] During normal operation of the filter of the present
invention, assembly 5040 is located mainly within volume 5021 and
shaft 5050 is sealingly coupled to the top portion 5014 of the
housing by means of a sealing collar 5068 which sealingly engages
threading on shaft 5050 and on the top portion 5014. Valve 5067 is
oriented as shown in FIG. 29 such that liquid to be filtered enters
from source 66 and passes to inlet 5018 and through the stack of
filter elements 5019 from the upstream surface to the downstream
surface, being filtered in the process. The filtered liquid passes
through volume 5021 and through the apertures formed in base 5054
to outlet 5020. Valve 5053 is closed.
[0220] During backflush operation, valve 5067 is manipulated to
close off pressurized liquid source 5066 and to provide
communication between inlet 5018 and backflush drain 5063. Valve
5053 is opened to provide a pressurized flow of water to assembly
5040, and collar 5068 is disconnected.
[0221] High pressure spray outlet head 5056 is manually
reciprocated axially along the interior of the stack of filter
elements at the downstream surface, causing a high pressure
concentrated jet of water to impinge on the downstream surface
thereof for dislodging accumulated filtered material from the stack
of filter elements. This arrangement enables substantially the
entire downstream surface to be thus scanned, region by region, by
the high pressure concentrated jet for efficient backflush cleaning
of the stack of filter elements.
[0222] Reference is now made to FIGS. 32, 33 and 35 which
illustrate a filter constructed and operative in accordance with a
preferred embodiment of the present invention and comprising a base
5070 on which is fixedly supported a bottom housing portion 5072.
Removably mounted onto the bottom housing portion 5072 is a top
housing portion 5074, which is maintained in sealing engagement
therewith by means of a sealing ring 5076.
[0223] A fluid inlet 5078 is provided adjacent the bottom of
housing portion 5072 and communicates with the outside cylindrical
surface, hereinafter termed the "upstream surface", of a stack of
filter elements 5079. A fluid outlet assembly 5080 is coupled to
housing portion 5072 and communicates with a hollow interior
portion 5081 of stack of filter elements 5079 adjacent the inner
cylindrical surface of the stack of filter elements, hereinafter
termed the "downstream surface".
[0224] The stack of filter elements 5079 preferably comprises a
stack of hollow center filter disks 5082 of any suitable type.
Alternatively, the stack of filter elements may be replaced by any
other suitable type of filter element such as a cartridge or
cylindrical mesh filter. Suitable filter disks are described in the
U.S. Patent Applications listed hereinabove in the "Background of
the Invention", and are operative to remove particulate matter from
liquids passing therethrough from the upstream surface to the
downstream surface. A preferred filter disk arrangement is
described and claimed in co-pending Israel Patent Application
78160, filed Mar. 14, 1986, the disclosure of which is incorporated
herein by reference.
[0225] The stack of filter elements 5082 is preferably removably
mounted in coaxial relationship so as to define volume 5081 and is
retained in suitably tight engagement by means of top and bottom
retaining collars 5084 and 5086 joined by a plurality of threaded
rods 5088, typically four in number, and associated nuts 5090. A
collar member 5092 engages retaining collar 5084 for retaining
cover portion 5074 onto stack of filter elements 5079 and onto the
bottom housing portion 5072.
[0226] A high pressure spray nozzle assembly 5100 is disposed
mainly within volume 5081 and comprises a water supply shaft 5110
having a water inlet 5112 and an associated inlet valve 5114.
[0227] A manually rotatable outlet head 5116 is arranged for
relatively free rotation about a rotation axis 5118 defined in
shaft 5110 and is preferably provided with a single output aperture
5119. According to a preferred embodiment of the invention, there
is provided surrounding outlet aperture 5119 a flange 5120 which is
curved to correspond to the curvature of the inner, downstream,
surface 5122 of the stack of filter elements and to generally
tightly engage same, such that the water stream exiting from outlet
aperture 5119 is forced into the volume of the stack of filter
elements facing the outlet aperture and is not permitted to be
spread out, thus reducing its strength and its backflushing
efficiency.
[0228] As noted particularly in FIG. 35, it is also a particular
feature of the present invention that the outlet aperture 5119 has
a limited height, which corresponds to the axial spacing, i.e.
along axis 5118, between adjacent filter elements 5082, as well as
a limited azimuthal extent, corresponding to the width of a
filtering chamber defined between adjacent filter elements 5082 and
between generally radially extending separations defined thereby.
This arrangement is provided such that as the outlet aperture 5119
is displaced up and down and rotated about axis 5118, the
pressurized stream produced thereby sequentially is concentrated on
individual filtering chambers defined in the stack of filter
elements to provide enhanced backflushing thereof.
[0229] As noted above, outlet aperture 5119 is arranged to provide
a radially directed concentrated high pressure backflushing jet,
which serves to flush particulate matter from the stack of filter
elements 5079.
[0230] Inlet 5112 is typically coupled via a flexible hose (not
shown) to a backflush liquid supply which may be connected to a
pressurized source of liquid to be filtered which communicates with
the inlet 5078 via a two way valve 5121. Valve 5121 selectably
couples the water inlet 5078 of the filter either to the
pressurized source 5066 or to a backflush liquid drain 5123.
[0231] During normal operation of the filter of the present
invention, assembly 5100 is located mainly within volume 5081 and
shaft 5110 is sealingly coupled to the top portion 5074 of the
housing by means of a sealing collar 5124 which sealingly engages
threading on shaft 5110 and on the top portion 5074. Valve 5121 is
oriented as shown in FIG. 32 such that liquid to be filtered enters
from the pressurized source and passes to inlet 5078 and through
the stack of filter elements 5079 from the upstream surface to the
downstream surface, being filtered in the process. The filtered
liquid passes through volume 5081. Valve 5114 is closed.
[0232] During backflush operation, valve 5121 is manipulated to
close off the pressurized liquid source and to provide
communication between inlet 5078 and backflush drain 5123. Valve
5114 is opened to provide a pressurized flow of water to assembly
5100 and collar 5124 is disconnected.
[0233] High pressure stream outlet head 5116 is manually
reciprocated axially along the interior of the stack of filter
elements at the downstream surface and is manually rotated by at
least 360 degrees, causing a high pressure concentrated jet of
water to impinge on the downstream surface thereof for dislodging
accumulated filtered material from the stack of filter elements.
This arrangement enables substantially the entire downstream
surface to be thus scanned, region by region, by the high pressure
concentrated jet for efficient backflush cleaning of the stack of
filter elements.
[0234] Reference is now made to FIGS. 34 and 36, which illustrate
an alternative embodiment of the apparatus of FIG. 32, wherein a
high pressure stream outlet head 5132 having two oppositely
directed outlet apertures 5134 and 5136 is provided. According to a
preferred embodiment, the two apertures 5134 and 5136 are arranged
at different axial locations, with respect to axis 5118, as shown
in FIG. 36, thus providing simultaneous flushing of chambers at two
different axial locations along axis 5118.
[0235] Reference is now made to FIGS. 37 and 38 which illustrate a
filter constructed and operative in accordance with another
preferred embodiment of the present invention and comprising a base
5170 on which is fixedly supported a bottom housing portion 5172.
Removably mounted onto the bottom housing portion 5172 is a top
housing portion 5174, which is maintained in sealing engagement
therewith by means of a sealing ring 5176.
[0236] A fluid inlet 5178 is provided adjacent the bottom of
housing portion 5172 and communicates with the outside cylindrical
surface, hereinafter termed the "upstream surface," of a stack of
filter elements 5179. A fluid outlet assembly 5180 is coupled to
housing portion 5172 and communicates with a hollow interior
portion 5181 of stack of filter elements 5179 adjacent the inner
cylindrical surface of the stack of filter elements, hereinafter
termed the "downstream surface."
[0237] The stack of filter elements 5179 preferably comprises a
stack of hollow center filter disks 5182 of any suitable type.
Alternatively, the stack of filter elements may be replaced by any
other suitable type of filter element such as a cartridge or
cylindrical mesh filter. Suitable filter disks are described in the
U.S. Patent Applications listed hereinabove in the "Background of
the Invention", and are operative to remove particulate matter from
liquids passing therethrough from the upstream surface to the
downstream surface. A preferred filter disk arrangement is
described and claimed in co-pending Israel Patent Application
78160, filed Mar. 14, 1986, the disclosure of which is incorporated
herein by reference.
[0238] The stack of filter elements 5182 is preferably removably
mounted in coaxial relationship so as to define volume 5181 and is
retained in suitably tight engagement by means of top and bottom
retaining collars 5184 and 5186 joined by a plurality of threaded
rods 5188, typically four in number, and associated nuts 5190. A
collar member 5192 engages retaining collar 5184 for retaining
cover portion 5174 onto stack of filter elements 5179 and onto the
bottom housing portion 5172.
[0239] A high pressure spray nozzle assembly 5200 is disposed
mainly within volume 5181 and comprises a water supply shaft 5210
having a water inlet 5212 and an associated inlet valve 5214. A
fixed base portion 5216 is typically mounted onto shaft 5210 and
serves to maintain the nozzle assembly 5200 centered with respect
to volume 5181 and the downstream cylindrical surface of stack of
filter elements 5179. Base portion 5216 is typically formed in an
apertured manner to permit liquid flow therepast through volume
5181.
[0240] A rotating outlet head 5217 is arranged for relatively free
rotation about a rotation axis 5218 defined in shaft 5210 and is
preferably provided with first and second output apertures 5220 and
5222.
[0241] Referring now specifically to FIG. 38, it is seen that
rotating outlet head 5217 comprises a generally circular central
portion 5224 and first and second truncated-conical outlet conduits
5226 and 5228 which are offset from each other azimuthally with
respect to axis 5218 and which extend generally in parallel
opposite directions and terminate in respective apertures 5220 and
5222.
[0242] Pressurized water exiting apertures 5220 and 5222 in the
illustrated offset arrangement produces a rotational moment
resulting in rotation of head 5217 with respect to the stack of
filter elements.
[0243] Reference is now made to FIG. 39, which illustrates an
alternative embodiment of the invention wherein a different
configuration of rotating outlet head is employed. Here the outlet
head 5230 comprises an elongate central portion 5232 and two angled
outlet nozzles 5234 and 5236 coupled thereto. A further radially
directed outlet aperture 5238 may be provided and selectably
plugged as by a plug 5240.
[0244] It is noted that according to a preferred embodiment of the
invention, the directions of the pressurized streams produced by
the head 5230 are somewhat skewed from the radial and are
preferably aligned with the configuration of filtering chambers
5242 defined by the stack of filter elements, such that the streams
tend to fully penetrate to the interior of the filtering chambers
5242.
[0245] The remainder of the apparatus of FIGS. 37-39 is generally
similar to that of FIG. 29 and the operation thereof is similar.
Thus, for the sake of conciseness, descriptions of the similar
structure and operation are not here repeated.
[0246] Reference is now made to FIGS. 40 and 41 which illustrate an
alternative embodiment of the apparatus of FIG. 39, which is
generally similar thereto except for the fact that here an outlet
head 5270 comprises an generally circular central portion 5272 and
only a single radially offset outlet nozzle 5274.
[0247] The remainder of the apparatus of FIGS. 40 and 41 is
generally similar to that of FIG. 37 and the operation thereof is
similar. Thus, for the sake of conciseness, descriptions of the
similar structure and operation are not here repeated.
[0248] Reference is now made briefly to FIGS. 42A-42C. FIG. 42A
illustrates an outlet head 5280 having an elongate central portion
5282 and two nozzle receiving arms 5284 and 5286, which are
arranged at right angles thereto for receiving selectably
configured nozzle elements 5288. It is noted that nozzle elements
5288 have a slanted termination end 5290, which is intended to
correspond to the cylindrical configuration of the inner surface of
volume 5081 (FIG. 32) and thus enable relatively tight "sealing"
engagement therewith for maximum penetration of a pressurized water
stream into the filter element chambers. Outlet head 5280 is also
provided with a third outlet opening 5292 which defines an
extension of central portion 5282 and is blocked as by a plug
5294.
[0249] FIG. 42B illustrates a variation of the structure of FIG.
42A, wherein the arms 5296 and 5298 extend from the central portion
5300 other than at 90 degrees.
[0250] FIG. 42C illustrates the outlet head of FIG. 42B, wherein a
nozzle element 5302 is disposed in an outlet opening 5304 which
extends axially from central portion 5300, thus sealing the
adjacent outlet opening 5306.
[0251] Reference is now made to FIGS. 43-54, which illustrate two
alternative embodiments of stacks of filter elements, each
comprising a stack of filter disks constructed and operative in
accordance with a preferred embodiment of the invention. The stack
of filter disks is appropriate for use in any suitable filter
apparatus, and are particularly useful in the filter apparatus
described hereinabove.
[0252] Reference is made first to FIGS. 43-49C. The assembly shown
in these figures comprises alternating centrally apertured filter
elements 5410 formed of a plastic material, such as polypropylene.
The filter elements are of two types, indicated respectively by
reference numerals 5412 and 5414. Disks 5412 are typically formed
with identical first planar surfaces defining circumferential
grooves 5416, typically having a generally V-shaped cross section.
The dimensions of the grooves are determined by the fineness of the
filtering sought to be achieved thereby.
[0253] Disks 5414 typically comprise identically patterned opposite
second planar surfaces, the two planar surfaces of each filter
element 5414 typically being mirror opposites of each other, as can
be seen in FIGS. 49B and 49C. This out of phase arrangement
provides enhanced structural strength to filter element 5414 and
enables it to be made of relatively thin material.
[0254] Each planar surface of spacer filter element 5414 is formed
with a filter barrier defined by a raised line pattern 5420, which
preferably is arranged to extended continuously in generally
undulating configuration defining a plurality of radially extending
finger elements 5422 on the face of the planar surface. The raised
line pattern 5420 typically defines the outline of each finger
element 5422 and may be configured to define a smooth outline or
alternatively a notched or serrated pattern along the generally
radially extending portion of each finger element 5422.
[0255] Referring specifically to FIGS. 48 and 49B, it is seen that
the configuration of the finger element 5422 is preferably not
exactly radial, although for the purposes of this patent, it is
included within the definition of generally radially extending.
Specifically, the outline of each finger element is curved along a
portion of an arc. Each raised line portion is configured as part
of an arc about a different center, as illustrated in FIG. 48.
[0256] The resulting configuration provides a relatively enhanced
length of the line portion, and thus of the filter barrier per unit
area of the filter element. It will be appreciated that the filter
barrier defined by the raised line portion 5420 defines a barrier
between an upstream side of the filter, here typically the radially
outward side of the line portion, and the downstream side of the
filter, typically the radially inward side of the line portion.
Accordingly, it may be understood that an increase in the length of
the filter barrier per unit area of filter element provides a
corresponding increase in the filtering capacity of the unit per
unit area of filter element, and per unit volume of a filter
element made up of a stack of such filter elements.
[0257] It is a particular feature of the present invention that the
raised line portion 5420, defining the second planar surface of the
filter element 5414, is formed with an array of grooves 5424,
typically of the same general dimensions as grooves 5416. When the
first and second planar surfaces are arranged in juxtaposed
engagement, the raised line pattern 5420 engages the grooves 5416
of filter elements 5412, defining a filter barrier between the
upstream side of the filter and the downstream side. The spaces
between adjacent finger elements 5422 define filtering chambers, as
do the spaces defined interiorly of each finger element 5422. These
filtering chambers, it will be recalled, are particularly suitable
for pressurized backflush cleaning by the high pressure directed
backflush stream produced by the apparatus of FIGS. 29-42C
described hereinabove.
[0258] At the locations where the first and second planar surfaces
meet in touching engagement, grooves 5424 of the second surface
meet grooves 5416 of the first surface. Understanding of this
engagement may be assisted by a consideration of FIG. 45.
[0259] It is a particular feature of the present invention that
grooves 5416 and 5424 are mutually skewed, as illustrated in FIGS.
41 and 43, such that they define multiply intersecting paths for
fluid flow therethrough, there being defined at intervals along the
pathway a particle size gauge being the cross section of the single
groove.
[0260] This configuration has a number of advantages, including the
fact that along much of the pathway from the upstream side to the
downstream side across the engaged first and second surfaces, the
pathway is larger than the particle size gauge due to the effective
combination of grooves formed on the opposite facing surfaces. The
multiple interconnections between grooves provides multiple
alternative paths for fluid, such that fluid flow may continue
notwithstanding blockage of certain passageways. The relatively
long and intricate pathway of the fluid provides enhanced depth of
filtering, thus increasing filtering efficiency.
[0261] FIG. 49A shows a detailed illustration of the cross-section
of grooves 5424.
[0262] Reference is now made to FIGS. 44, 46 and 47, which
correspond to FIGS. 43 and 45 but show the collection of sediment
particles during operation of the filter. The illustration shows an
embodiment wherein the upstream side is radially outward of the
raised line portion 5420 and thus intermediate finger elements 5422
while the downstream side is at the radially inward side of the
raised line portion 5420 and thus communicates with the area and
volume interior of each finger element 5422.
[0263] It is seen that fluid, such as water, carrying particulate
matter, enters from the upstream side, as indicated by arrows 5430,
and deposits particulate matter 5432 upstream of the raised line
portion 5420. Consideration of FIG. 47 also indicates that further
particulate matter tends to be deposited within the area of
engagement of grooves 5416 and 5424 at locations where respective
ridges between the grooves on opposite surfaces intersect, defining
the maximum size gauge. It may thus be appreciated that particulate
matter tends to be deposited generally throughout the area of
engagement of grooves 5416 and 5424, thus providing enhanced depth
of filtering.
[0264] Reference is made now to FIGS. 46-54. The assembly shown in
these figures comprises a stack of identical filter elements 5510
formed of a plastic material, such as polypropylene. The filter
elements are all of a single type and typically comprise
identically patterned opposite second planar surfaces. The two
planar surfaces of each filter element may be mirror opposites of
each other, as can be seen in FIGS. 49B and 49C. This out of phase
arrangement provides enhanced structural strength to filter element
5510 and enables it to be made of relatively thin material.
[0265] Each planar surface of filter element 5510 is formed with a
filter barrier defined by a raised line pattern 5520, which
preferably is arranged to extended continuously in generally
undulating configuration defining a plurality of radially extending
finger elements 5522 on the face of the planar surface. The raised
line pattern 5520 typically defines the outline of each finger
element 5522 and may be configured to define a smooth outline or
alternatively a notched or serrated pattern along the generally
radially extending portion of each finger element 5522.
[0266] The configuration of finger element 5522 is similar to that
of finger element 5422 described hereinabove. Specifically, the
outline of each finger element is curved along a portion of an arc.
Each raised line portion is configured as part of an arc about a
different center, as illustrated in FIG. 48.
[0267] The resulting configuration provides a relatively enhanced
length of the line portion, and thus of the filter barrier per unit
area of the filter element. It will be appreciated that the filter
barrier defined by the raised line portion 5520 defines a barrier
between an upstream side of the filter, here typically the radially
outward side of the line portion, and the downstream side of the
filter, typically the radially inward side of the line portion.
Accordingly, it may be understood that an increase in the length of
the filter barrier per unit area of filter element provides a
corresponding increase in the filtering capacity of the unit per
unit area of filter element, and per unit volume of a stack of such
filter elements.
[0268] Similarly to the arrangement described hereinabove in
connection with FIGS. 43-49C, it is a particular feature of the
present invention that the raised line portion 5520, defining the
planar surface of the filter element 5510, is formed with an array
of grooves 5524, typically of the same general dimensions as
grooves 5424, described hereinabove, and governed by the same
criteria.
[0269] In the embodiment of FIGS. 50-54, the filter elements making
up the stack of filter elements are maintained in precise azimuthal
alignment, as by means of one or more azimuthal aligning rings 5525
associated with each stack of filter elements and registered by a
rod 5527 passing therethrough. Accordingly, when the first and
second planar surfaces are arranged in juxtaposed engagement, the
finger elements 5522 on the facing first and second planar surfaces
are in precise registration, defining a filter barrier between the
upstream side of the filter and the downstream side.
[0270] The spaces between adjacent finger elements 5522 define
filtering chambers, as do the spaces defined interiorly of each
finger element 5522. These filtering chambers, it will be recalled,
are particularly suitable for pressurized backflush cleaning by the
high pressure directed backflush stream produced by the apparatus
of FIGS. 29-42C described hereinabove.
[0271] It is a particular feature of the embodiment of FIGS. 50-54
that filtering chambers provided are of larger size than those
provided in the embodiment of FIGS. 43-49C. Accordingly more room
is provided for collection of particulate matter, the finger
elements may be located closer together in the plane of the stacks
of filter elements, and the filtering chambers have smooth
surfaces, providing less resistance to the pressurized fluid stream
during backflushing, thus enabling more efficient backflush
cleaning of the stack of filter elements.
[0272] At the locations where the first and second planar surfaces
meet in touching engagement, grooves 5524 on both planar surfaces
are engaged. Understanding of this engagement may be assisted by a
consideration of FIG. 52.
[0273] It is a particular feature of the present invention that
grooves 5526 and 5528 on the opposite engaging surfaces are
mutually skewed, as illustrated in FIG. 52, such that they define
multiply intersecting paths for fluid flow therethrough, there
being defined at intervals along the pathway a particle size gauge
being the cross section of the single groove.
[0274] This configuration has a number of advantages, including the
fact that along much of the pathway from the upstream side to the
downstream side across the engaged first and second surfaces, the
pathway is larger than the particle size gauge due to the effective
combination of grooves formed on the opposite facing surfaces. The
multiple interconnections between grooves provides multiple
alternative paths for fluid, such that fluid flow may continue
notwithstanding blockage of certain passageways. The relatively
long and intricate pathway of the fluid provides enhanced depth of
filtering, thus increasing filtering efficiency.
[0275] Reference is now made to FIGS. 51, 53 and 54, which
correspond to FIGS. 50 and 52 but show the collection of sediment
particles during operation of the filter. The illustration shows an
embodiment wherein the upstream side is radially outward of the
raised line portion 5520 and thus intermediate ringer elements 5522
while the downstream side is at the radially inward side of the
raised line portion 5520 and this communicates with the area and
volume interior of each finger element 5522.
[0276] It is seen that fluid, such as water, carrying particulate
matter, enters from the upstream side, as indicated by arrows 5530,
and deposits particulate matter 5532 upstream of the raised line
portion 5520. Consideration of FIG. 54 aIso indicates that further
particulate matter tends to be deposited within the area of
engagement of grooves 5526 and 5528 at locations where respective
ridges between the grooves on opposite surfaces intersect, defining
the maximum size gauge. It may thus be appreciated that particulate
matter tends to be deposited generally throughout the area of
engagement of grooves 5526 and 5528, thus providing enhanced depth
of filtering.
[0277] It may additionally be appreciated that a filter aid such as
diatomaceous earth, activated carbon or a filter cake may be
employed and disposed at the upstream side of the stack of filter
elements. Depending on the nature of the filter aid used, it may
also be disposed at the area at which the first and second surfaces
engage.
[0278] A filter aid may be associated with each and every one of
the embodiment of this invention hereinabove disclosed. The filter
aid may be disposed within the liquid to be filtered or the
material of the filter itself may be pre-coated with filter aid to
facilitate the first stage of filtering. The filter aid does not
pass through the filter, but rather cakes upon its upstream
surface, forming a porous, permeable, insoluble cake, the apertures
within which are much smaller than those of the filter material.
This cake prevents even the finer solids within the liquid to be
filtered from passing through the filter; moreover it considerably
increases both the flow rate and the time before it becomes
necessary to clean or unclog the filter, as such matter which would
otherwise be caught in the filter itself will in such an embodiment
of any of the embodiments of this invention be caught in the filter
aid cake.
[0279] It will be appreciated by persons skilled in the art that
the present invention is not limited by what has been shown and
described hereinabove. Rather the scope of the present invention is
defined solely by the claims which follow:
* * * * *