IL83950A - Filter apparatus - Google Patents

Description

FILTER APPARATUS Mordeki Drori >;ma C: 05498 G5498dro.dis 1-392 18.9 - 1987 FIELD OF THE INVENTION The present invention relates to fluid filters and more particularly to fluid filters employing a filter aid, such as diatomaceous earth or activated carbon, associated with a filter element.

BACKGROUND OF THE INVENTION Various types of filters are known in the marketplace and in the patent literature.

Multiple-disk type filters generally include a housing in which the filter body within the housing is in the form of a stack of 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.

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.

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. Patents 4,026,806; 4 , 042 , 504 ; 4 , 045 , 345 ; 4,271, 018 ; 4.295.963.

SUMMARY OF THE INVENTION The present invention seeks to provide a fluid filter incorporating a filter aid material having enhanced regeneration features as compared with the prior art.

There is thus provided in accordance with a preferred embodiment of the present invention a fluid filter comprising a housing, a filter element disposed in the housing and arranged to receive a flow of fluid to be filtered from an upstream side of the element to a downstream side thereof, a fluid inlet disposed at the bottom of the housing, fluid distributor apparatus associated with the fluid inlet for distributing fluid entering at the fluid inlet about the interior of the housing in communication with the upstream side of the filter element, and a fluid outlet in communication with the downstream side of the filter element.

There is also provided in accordance with a preferred embodiment of the present invention a fluid filter comprising a housing, a filter element disposed in the housing and arranged to receive a flow of fluid to be filtered from an upstream side of the element to a downstream side thereof, a fluid inlet disposed at the bottom of the housing, a fluid outlet in communication with the downstream side of the filter element, and apparatus for causing disengagement of filter aid material associated with said upstream side of said filter element so as to enable regeneration of said filter aid material.

Additionally in accordance with a preferred embodiment 83950/2 of the invention the apparatus for causing disengagement comprises means for producing rotation of the filter element.

Further in accordance with a preferred embodiment of the invention, the apparatus for causing disengagement comprises means for impacting said filter element.

Additionally in accordance with a preferred embodiment of the invention, the apparatus for causing disengagement comprises means for forcing fluid from the downstream side through the filter element to the upstream side.

Further in accordance with an embodiment of the invention, the means for forcing fluid comprises a selectably orientable piston assembly.

Additionally in accordance with a preferred embodiment of the invention, the selectably orientable piston assembly comprises a hinged, foldable piston.

According to an alternative embodiment of the invention, the selectably orientable piston assembly comprises a pivotable piston.

Additionally in accordance with a preferred embodiment of the invention, there is also provided a pressure responsive valve associated with said fluid outlet.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: Fig. 1A is a detailed sectional illustration of an inlet and outlet assembly for a filter housing constructed and operative in accordance with a preferred embodiment of the present invention; Fig. IB is a sectional illustration taken along the lines B - B in Fig, 1A; Fig. 2 is a side sectional illustration of a fluid filter constructed and operative in accordance with an embodiment of the present invention and including a handle for enabling rotation of the filter element and a backflushing nozzle; Fig. 3 is a side sectional illustration of a fluid filter constructed and operative in accordance with another embodiment of the present invention and including a handle for enabling rotation of the filter element and an elevated outlet conduit; Fig. 4A is a side sectional illustration of a fluid filter constructed and operative in accordance with yet another embodiment of the present invention and including a foldable piston in a first operative orientation; Fig. 4B is a side sectional illustration of the fluid filter of Fig. 4A in a second operative orientation; Fig. C is a plan view illustration of the foldable piston employed in the embodiment of Figs. 4A and 4B; Fig. 5A is a side sectional illustration of a fluid filter similar to that of Figs. and 4B, including a pressure responsive valve, but without the backflush nozzle; Fig. 5B is a side sectional illustration of a fluid filter similar to that of Figs. ^A, 4B, and 5A but having a different piston structure; Fig. 5C is a side view illustration of the piston structure of Fig. 5B in an alternative operative orientation; Fig. 6 is a side view illustration of a fluid filter similar to that of Fig. 3 but having a different type of filter element; and Fig. 7 is a plan view illustration of the filter element of Fig. 6.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Reference is now made to Figs. 1A and IB, which illustrate an inlet and outlet assembly for a filter housing in accordance with a preferred embodiment of the present invention. As seen in Fig, 1A, the filter comprises a support base 10 which supports a filter housing 12 having a central bottom aperture 14. A manifold 16 is sealingly mounted onto filter housing 12 at aperture 14 by means of a threaded deflector collar member 18, which engages external threadings 22 formed onto a central hollow shaft portion 24 of manifold 16.

Deflector collar member 18 is formed with a plurality of ribs 25, which define peripheral shoulders 26 which engage the corresponding peripheral rim defined in the filter housing 12 about aperture 14. A peripheral sealing ring 28 is pressed between the manifold 16 and the underside of the filter housing 12 about aperture 14.

An inlet pipe 30 and an outlet pipe 32 are each fixedly disposed in operative association with the manifold. The inlet pipe 30 communicates with an annular conduit 3^ which surrounds shaft portion 24.

The annular outlet of conduit 3^ communicates via passages 36 defined between ribs 25 with an annular volume 37 that underlies a distributor plate 38. Distributor plate 38 is typically fixedly mounted onto collar member 18 and is arranged to separate volume 37 from the remainder of the interior of the filter housing 12. Distributor plate 38 is formed with a plurality of apertures 40 generally evenly azimuthally distributed thereon, so as to permit exit of fluid from volume 37 in a distributed manner over the entire 36Ο degrees of azimuth defined thereby. The fluid exiting from volume 37 via apertures 40 communicates with the upstream side of a filter element (not shown) located within filter housing 12. The arrangement of the filter element in the filter housing 12 is illustrated inter alia in Figs. 2 - 6.

The interior of the hollow shaft portion 24 communicates with the downstream side of the filter element (not shown in Fig. 1), in a manner shown inter alia in Figs. 2 - 6. Outlet pipe 32 communicates directly with the interior of the hollow shaft portion 24.

Deflector collar member l8 is formed with a support shoulder 42 and is provided with a sealing ring 44 for sealingly mounting of a filter element (not shown) thereon.

It may be appreciated that when joined as described hereinabove, filter housing 12, manifold 16 and deflector collar member l8 operate as a single unit, as if integrally formed. Alternatively the entire inlet and outlet assembly may be integrally formed.

The operation of the apparatus shown in Figs. 1A and IB will now be summarized. A fluid, such as water, enters through inlet pipe 30 and flows upwardly through annular conduit 34, defined by manifold 16. The water flows out through passages 36 defined by deflector collar member 18 and enters volume 37· The water is distributed about the azimuth of the filter by distributor 38, which causes it to pass through apertures 40, formed therein. The water then passes through the filter element (not shown in Fig. 1 ) from the upstream side thereof to the downstream side thereof. From the downstream side, the filtered water passes through the interior of the hollow shaft portion 24 of the manifold 16 and then out the outlet pipe 32.

Reference is now made to Fig. 2 , which illustrates a fluid filter constructed and operative in accordance with a preferred embodiment of the present invention and preferably including an inlet and outlet assembly of the type described above and shown in Figs. 1A and IB.

A filter element 44, such as a disc filter element of the type described in Israel Patent Application No. 83330 , the disclosure of which is incorporated herein by reference, is seated on and supported by support shoulder 42 (Fig. 1 ) defined by deflector collar member 18. It is particularly noted that support shoulder 42 provides a rotatable support for filter element 44, permitting rotation thereof relative to deflector collar member 18.

Filter element 44 is defined by top and bottom securing elements 46 and 48 , which lie at respective top and bottom ends of a stack 50 of filter disks. The filter element 44 is held together tightly by a plurality of axial bolts 52 which are secured by suitable nuts ^ adjacent respective top and bottom securing elements. Filter disks are preferably of the type described in Israel Patent Application 83330 , the disclosure of which is incorporated herein by reference.

Bottom securing element 48 is seated onto shoulder 42 , while top securing element 46 sealingly engages a rotatable mounting yoke 56 , which supports and stabilizes the filter element 44 from above. The engagement between top securing element 46 and rotatable mounting yoke 56 includes the provision of axial protrusions 58 on top securing element 46, which engage radially extending protrusions 60 formed onto yoke 56 , such that the rotation of yoke 5 about a central axis 62 produces rotation of top securing element 46 and thus of the entire filter element about axis 62. Yoke 5 also defines a shoulder 64 which locates top securing element 46 axially and a peripheral inner positioning surface 66, which locates the top securing element 46 radially with respect to axis 62. A sealing ring 68 is preferably associated with surface 66 for providing sealing between element 46 and yoke 56.

Rotatable yoke 5 is integrally formed with a neck portion 69 , which extends upwardly through a central top aperture 70 formed in a top portion 72 of the filter housing. Rotatable yoke 56 is removably sealingly mounted onto top portion 72 by means of a collar member 74 , which threadably engages neck portion 69 and which is formed with a handle 76. When collar member 74 is tightly threaded onto neck portion 69 , an upper surface 78 of yoke 56 is disposed in rotatable sealing engagement with the top portion 72 of the filter housing about aperture 70 , such that rotation of the handle in either direction produces corresponding rotation of yoke 56. Rotation of yoke 56 results in rotation of filter element 44 due to the interdigitation of protrusions 58 and 60 as described above.

A rotating backflush jet assembly 80 including a rotating nozzle 82 , an apertured positioning element 84, a support and supply pipe 86 , an angled top portion 88 , a water supply valve 90 and a connector 2 to a flexible water supply hose 94. is selectably slidably mounted about central axis 62 and extends through a bore 4 formed in yoke 5 . Jet assembly 80 is selectably secured to neck portion 69 by means of a rubber ring seal which can be pressed inwardly to fractionally engage pipe 86 by tightening of a cap screw 96 thereover in threaded engagement with neck portion 69.

The operation of the apparatus of Fig. 2 will now be summarized. Water to be filtered passes through the inlet and outlet assembly precisely as described hereinabove in connection with Figs. 1A and IB, from the upstream side of the filter element 44 to the downstream side thereof and out through outlet pipe 32. Upon termination of the flow of water to be filtered into the filter, such as upon termination of the operation of a pump which produces the flow, an operator rotates handle 76 about axis 62 in either a continuous motion or a back and forth motion, thus causing rotation of the filter element 44 relative to the water contained therein. This relative rotation causes disengagement of filter aid material from the upstream surface of the filter element, such that such filter aid material falls to the bottom of the upstream volume of the filter, interior of a bottom portion 98 of filter housing 12.

Renewed supply of water to the filter via inlet pipe 30 , the deflector and the distributor causes the filter aid material to be redistributed over the upstream surface of the filter element and thus be effectively regenerated, significantly extending its useful operating lifetime.

Reference is now made to Fig. 3, which shows an alternative embodiment of filter, which is similar to that of Fig. 2, but does not include a backflush nozzle assembly. Here, the inlet and outlet assembly may be identical to that of Fig. 2, as may be the filter element 44. In contrast to the embodiment of Fig. 2, here the top securing element 100 may be integrally formed with a rotatable yoke 102. Yoke 102 is preferably formed with a pair of spaced upstanding protrusions 104 disposed on either side of a central aperture 106.

A handle 108 is rotatably mounted via an arm 110 for rotation on an axle 112, which is arranged along a longitudinal axis 114 of the filter. Axle 112 sealingly and rotatably extends through a central aperture 116 formed about axis 114 in top cover portion 72 of the filter housing 12. Axle 112 is secured in position axially by means of an integrally formed bottom abutment member 118 disposed below top cover portion 72 and of a threaded nut 120, disposed above top cover portion 72. An 0 ring 122 is disposed between the axle 112 and the top cover portion 72 to prevent escape of fluid from the filter housing.

Axle 112 extends downwardly and through central aperture 106 of yoke 102 in sealing engagement therewith. Extending transversely through axle 112 just above yoke 102 and in driving engagement with upstanding protrusions 104 is a drive member 124, which upon rotation of handle 108 and axle 112, produces rotation of the yoke 102 and thus of the filter element 44 about axis 114. 83950/2 It will be noted that in the embodiment of Fig. 3, an upward continuation of the hollow shaft portion 24 is defined by the addition of a central outlet pipe 126 in the downstream region interior of the filter element 44 and axially centered about axis 114. Central outlet pipe 126 is threadably mounted at its bottom portion onto distributor collar member 18 so as to define an extension of the hollow shaft portion 24 and terminates just below the top of the filter element. This arrangement ensures that upon termination of the supply of water to inlet 30, the filter housing 12 will remain full of water up to the top of central outlet pipe 126.

Operation of the apparatus of Fig. 3 is identical to that of Fig. 2, with the exception that backflushing is not provided. Thus, when it is desired to remove the filter aid and clean the filter element, the housing 12 must be opened and the filter element removed for backflushing as by the type of nozzle shown in Fig. 2.

Reference is now made to Figs. 4A - 4C, which illustrate yet another alternative embodiment of the present invention in first and second operative embodiments. The structure of the inlet and outlet assembly and of the filter element may be identical to that of the embodiment of Fig. 2, with the exception that the filter element and the yoke are fixedly mounted onto the filter housing top portion, and not rotatable, no handle being provided.

The rotating jet backflush assembly 80 may be identical to that shown in Fig. 2. However, a foldable piston assembly 130 is preferably associated with pipe 86, just above apertured positioning element 84. A preferred structure of foldable piston assembly 130 is shown in Fig. 4C, where it is seen that the piston assembly 130 comprises a central portion 132, which is fixedly mounted onto pipe 86, and a pair of side portions 134, hinged onto opposite sides of central portion 132.

As seen in Figs. 4A and 4B, there are associated with each of the pair of side portions 134. a retaining protrusion I36, which allows the side portion 134 to pivot downwardly, but restricts the side portion to an approximate 90 degree orientation, when it is pivoted upwardly.

The operation of the apparatus of Figs. 4A - 4C will now be summarized. Upon termination of the supply of water to be filtered at inlet 30, cap nut 96 is unscrewed so as to permit the backflush assembly 80 to be raised and lowered along axis 62. Fig. 4A illustrates the orientation of the backflush assembly as it is being raised, wherein the piston assembly 130 is in its folded orientation. As seen in Fig. 4B, which shows the piston assembly 130 as it is being lowered, the resistance of the water in the filter housing causes the piston assembly 130 to assume its extended orientation, such that downward movement of the piston asssembly 130 causes water to be forced in a backflush direction through the filter element from the downstream side to the upstream side.

The forced movement of water due to the action of the piston assembly 130 causes filter aid material adhering to the upstream side of the filter element to disengage therefrom and fall to the bottom of the interior of the filter housing 12. It is appreciated that the disengagement of the filter aid material is produced even without the provision of a backflush spray through the backflush nozzle. In fact, normally, the disengagement of the filter aid material from the filter element occurs when the backflush jet is not operated, it being noted that the provision of the piston assembly 130 does not interfere with normal backflushing operation of the backflush assembly 80.

The accumulated filter aid on the bottom of the housing is reoriented onto the upstream side of the filter element upon resupply of water to inlet 30, thus providing regeneration of the filter aid material.

Reference is now made to Fig. 5A, which illustrates yet another embodiment of filter constructed and operative in accordance with a preferred embodiment of the present invention. This embodiment is identical to that of Figs. *JA and 4B with the following exceptions: The backflush assembly 80 is here replaced by a simple rod l40 on which is mounted the foldable piston 130. Also, a conventional pressure maintaining value 142 is associated with outlet pipe 32. The pressure maintaining valve 142 is operative to prevent outflow of water through the outlet pipe 32 except when water is being pumped into the inlet at at least a predetermined pressure. When such pumping is terminated, valve 142 is closed, thus keeping the interior of the filter housing 12 full of water.

The valve 1^2 is configured and operative such that the downward piston action of piston assembly 130 does not cause opening of the valve. Accordingly, when the piston assembly 130 is moved downwardly along central axis 62, the flow of water through the filter element from the downstream side of the filter element to the upstream side thereof causes disengagement of filter aid material from the upstream side of the filter element, such that that material falls to the bottom of the interior of the filter element. Subsequent resumption of the supply of water at inlet pipe 30 causes the filter aid material to readhere to the upstream side of the filter element in a different arrangement, thus completing the regeneration of the filter aid material .

Reference is now made to Figs. 5B and 5C which illustrate still another embodiment of a filter constructed and operative in accordance with a preferred embodiment of the present invention. This embodiment is identical to that of Fig. 5A with the following exceptions: The valve l 2 is not provided, although alternatively it could be provided. Secondly, the structure of the foldable piston of the type shown in Fig. 4C is replaced by a pivotable piston assembly 150, as shown in Fig. 5C.

As seen in Figs. B and 5C, the piston assembly 150 comprises a mounting collar 152, including a mounting protrusion I54 onto which is pivotably mounted a corresponding mounting protrusion 156 of a generally circular piston element 158, for rotation about a pivot axis 160, which lies perpendicular to axis 62. Fig. B illustrates the piston assembly 1 0 in an operative orientation during downward movement of rod l40, while Fig. 5C illustrates the piston assembly in a pivoted orientation, as during upward movement of the rod l40.

Reference is now made to Figs. 6 and 7 which illustrate a further alternative embodiment of the present invention, employing a conventional non-disc filter element, such as that manufactured and sold by PAC-FAB.

The arrangement of the inlet and outlet assembly and of the handle may be identical to that shown in Fig. 3· Here, however, the yoke is replaced by an integrally formed filter element 170 including a central portion 172 and outwardly extending portions 174. Filter element 170 is rotatably supported onto the top rim 176 of outlet pipe 126 and defines a circular peripheral positioning shoulder 178 which serves to center the filter element 170 about central axis 114.

Rotation of the filter element 170 with respect to the filter housing 12 is provided by means of a pair of upstanding protrusions l80 and 182, which are drivingly engaged by transverse driving rod 124, as described hereinabove in connection with Fig. 3· The operation of the filter element 170 and particularly the regeneration of the filter aid material adhering to the upstream side of the filter element 170 in response to rotation of the filter element is essentially the same as described hereinabove in connection with Fig. 3· It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention is defined only by the claims which follow:

Claims (12)

C L A I M S

1. A fluid filter comprising: a housing; a filter element disposed in said housing and arranged to receive a flow of fluid to be filtered from an upstream side of said element to a downstream side thereof; a fluid inlet disposed at the bottom of said housing; fluid distributor means associated with said fluid inlet for distributing fluid entering at said fluid inlet about the interior of said housing in communication with said upstream side of said filter element; and a fluid outlet in communication with said downstream side of said filter element.

2. A fluid filter comprising: a housing; a filter element disposed in said housing and arranged to receive a flow of fluid to be filtered from an upstream side of said element to a downstream side thereof; a fluid inlet disposed at the bottom of said housing; a fluid outlet in communication with said downstream side of said filter element; and means for causing disengagement of filter aid material associated with said upstream side of said filter element so as to enable regeneration of said filter aid material.

3. A fluid filter according to claim 2 and wherein said means for causing disengagement comprises means for producing rotation of said filter element.

4. A fluid filter according to claim 2 and wherein said means for causing disengagement comprises means for impacting said filter element.

5. · A fluid filter according to claim 2 and wherein said means for causing disengagement comprises means for forcing fluid from said downstream side through said filter element to said upstream side.

6. A fluid filter according to claim 5 an wherein said means for forcing fluid comprises a selectably orientable piston assembly.

7. · A fluid filter according to claim 6 and wherein said selectably orientable piston assembly comprises a hinged, foldable piston.

8. A fluid filter according to claim 6 and wherein said selectably orientable piston assembly comprises a pivotable piston.

9. A fluid filter according to any of the preceding claims and also comprising a pressure responsive valve associated with said fluid outlet.

10. A fluid filter according to any of claims 2 - 9 an also comprising fluid distributor means associated with said fluid inlet for distributing fluid entering at said fluid inlet about said interior of said housing in communication with said upstream side of said filter element.

11. Apparatus substantially as shown and described hereinabove .

12. Apparatus substantially as illustrated in any of the drawings .