FILTER ARRANGEMENTS

Abstract

A filter arrangement includes a cleaning mechanism for cleaning at least one screen filter of the filter arrangement. The cleaning mechanism has a flush chamber, a central hollow core that extends through the flush chamber, and suction nozzles fitted to the core. The core extends between opposing axial ends that are located outside of the flush chamber in exposure to substantially similar pressures at least during a cleaning operation of the cleaning mechanism.

Claims

1. A filter arrangement comprising a cleaning mechanism for cleaning at least one screen filter of the filter arrangement, the cleaning mechanism comprising: a flush chamber; a central hollow core that extends through the flush chamber; and suction nozzles fitted to the core; wherein: the core extends between opposing axial ends that are located outside of the flush chamber; and the opposing axial ends are exposed to substantially similar pressures, at least during a cleaning operation of the cleaning mechanism.

2. The filter arrangement of claim 1, wherein liquid sucked in by the suction nozzles and flowing through the core is discharged out of the filter arrangement via the flush chamber during a cleaning operation.

3. The filter arrangement of claim 2, wherein: a cleaning operation applied to a full axial extent of the at least one screen filter constitutes a cleaning cycle; and the core is configured to axially move between two opposing axial positions, during a single cleaning cycle.

4. The filter arrangement of claim 1, further comprising: at least one helical rail formed along an inner side of the screen filter, and wherein: during a cleaning operation, at least some of the suction nozzles are prevented from engaging the inner side of the screen filter through engagement with the helical rail.

5. The filter arrangement of claim 1, further comprising a turbine through which liquid flows during a cleaning operation, and wherein the flow of liquid through the turbine is arranged to urge rotation of the core.

6. The filter arrangement of claim 5, further comprising a driving member for transforming rotation of the core also to axial movement of the core.

7. The filter arrangement of claim 6, wherein: the core comprises opposing core segments extending away from the flush chamber in opposing axial directions, and each core segment comprises suction nozzles.

8. The filter arrangement of claim 5, wherein the turbine is located within the flush chamber of the filter arrangement.

9. The filter arrangement of claim 5, wherein the turbine is disc shaped about an axial extension of the core.

10. The filter arrangement of claim 9, further comprising at least one channel set formed in the turbine for urging torque upon the turbine and the core, as liquid flows through the channel set.

11. The filter arrangement of claim 10, wherein: the at least one channel set is two channel sets, and torque formed by a first one of the channel sets when liquid flows therethrough is in an opposing direction to the torque formed by the other channel set when liquid flows therethrough.

12. The filter arrangement of claim 11, wherein during a cleaning operation, liquid is prevented from flowing simultaneously through the two channel sets.

13. The filter arrangement of claim 9, wherein: the turbine comprises two disc members and two channels sets; each channel set is formed within a respective one of the disc members; a first one of the channel sets is arranged for urging torque about the core's axis in a first rotational direction as liquid flows therethrough; and a second one of the channel sets is arranged for urging torque about the core's axis in an opposing, second rotational direction as liquid flows therethrough.

14. The filter arrangement of claim 13, wherein the two disc members are axially spaced apart from each other.

15. The filter arrangement of clam 5, wherein a passage through the central hollow core is divided into two separate passageways.

16. The filter arrangement of claim 15, wherein a barrier dividing the two separate passageways is located within a segment of the core that extends within the flush chamber.

17. The filter arrangement of claim 16, wherein the turbine is formed about the core at the same location where the barrier is located.

18. The filter arrangement of claim 17, comprising two screen filters, wherein the two separate passageways allow for cleaning only one of the two screen filters at a time.

19. The filter arrangement of claim 18, wherein during a cleaning operation the turbine is arranged to be urged to slide along the core in order to shift between the screen filters being cleaned.

20. The filter arrangement of claim 18, wherein during a cleaning operation, the turbine is arranged to be urged to rotate about the core in order to shift between the screen filters being cleaned.

21. The filter arrangement of claim 5, further comprising: at least one helical rail formed along an inner side of the screen filter, and wherein: during a cleaning operation, at least some of the suction nozzles are prevented from engaging the inner side of the screen filter through engagement with the at least one helical rail.

22. The filter arrangement of claim 5, further comprising: at least one helical rail formed along an inner side of the screen filter, wherein: the at least one helical rail is configured to act as a driving member for transforming rotation of the core also to axial movement of the core.

23. The filter arrangement of claim 5, wherein the turbine is located within the central hollow core.

24. The filter arrangement of claim 23, wherein the turbine is located at an end of the central hollow core, adjacent the flush chamber.

25. A filter arrangement having at least one screen filter with an inner side, and comprising: a cleaning mechanism for cleaning the at least one screen filter, the cleaning mechanism comprising a central hollow core having an axis, and suction nozzles fitted to the core; and at least one helical rail formed along the inner side of the screen filter, the at least one helical rail configured to guide a cleaning operation of the cleaning mechanism through engagement between at least some of the suction nozzles and the at least one helical rail.

26. The filter arrangement of claim 25, wherein during engagement between said at least some of the suction nozzles and the at least one helical rail, tips of the suction nozzles are prevented from engaging the inner side of the screen filter.

27. The filter arrangement of claim 25, wherein: the core is arranged to rotate about its axis during a cleaning operation; and guiding the cleaning operation comprises transforming rotation of the core also to axial movement of the core through the engagement between said at least some of the suction nozzles and the at least one helical rail.

28. The filter arrangement of claim 25, wherein: segments of the at least one helical rail are placed on lateral sides of suction tips of said at least some of the suction nozzles, to thereby limit liquid from being sucked into such suction nozzles from such lateral sides, and direct suction into such suction nozzles in a radial direction from the inner side of the screen filter.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0058] Exemplary embodiments are illustrated in referenced figures. It is intended that the embodiments and figures disclosed herein are to be considered illustrative, rather than restrictive. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying figures, in which:

[0059] FIG. 1A schematically shows an isometric view of an embodiment of a generally symmetrical filter arrangement in accordance with the present invention.

[0060] FIG. 1B shows an assembled view of the cleaning system of the filter arrangement of FIG. 1A.

[0061] FIG. 1C shows an exploded view of the cleaning system seen in FIG. 1B.

[0062] FIG. 1D shows a cutaway view of the filter arrangement of FIG. 1A, along with enlarged portions of the cutaway view, to illustrate water flow through the device;

[0063] FIG. 1E schematically shows top and two cross-sectional side views of a first embodiment of a generally non-symmetrical filter arrangement in accordance with the present invention; FIG. 1EC is the top view, FIG. 1EA is a cross-sectional side view taken along lines A-A of FIG. 1EC while FIG. 1EB is a cross-sectional side view taken along lines B-B of FIG. 1EC;

[0064] FIG. 1F schematically shows top and two cross-sectional side views of a second embodiment of a generally non-symmetrical filter arrangement in accordance with the present invention; FIG. 1FC is the top view, FIG. 1FA is a cross-sectional side view taken along lines A-A of FIG. 1FC while FIG. 1FB is a cross-sectional side view taken along lines B-B of FIG. 1FC;

[0065] FIG. 2 schematically shows a possible self-reversing screw and blade nut-type configuration that may be used in embodiments of a filter arrangements of the present invention;

[0066] FIGS. 3 to 6 schematically show various turbines that may be used in filter arrangement embodiments:

[0067] FIG. 3 shows a first turbine embodiment that may be used in filter arrangement embodiments, in which FIG. 3A is an isometric view of the turbine, FIG. 3B is a cutaway isometric view of the turbine and FIG. 3C is a plan view of the turbine;

[0068] FIG. 4A shows a second turbine embodiment that includes first and second disc members which create torque in opposite rotational directions, in which FIG. 4AA shows a side view of the turbine assembly, FIG. 4AB shows the first turbine disc, FIG. 4AC shows the second turbine disc and FIG. 4AD shows a schematic of the environment of the second turbine embodiment;

[0069] FIG. 4B shows a reversing mechanism for altering rotational direction when a disc member engages a barrier in the turbine of FIG. 4A;

[0070] FIG. 4C shows the operational stages of the reversing mechanism in the turbine of FIG. 4B, in which FIG. 4CA shows a first stage, FIG. 4CB shows a second stage, FIG. 4CC shows a third stage, and FIG. 4CD shows a fourth (final) stage;

[0071] FIG. 5 shows a third turbine embodiment having a disc with two sets of channels, each for creating torque in a different rotational direction, in which FIG. 5A shows a side view of the turbine assembly, FIG. 5B shows a core having a bulge for use in the third turbine embodiment, FIG. 5C shows a disc having a groove for engaging the bulge and FIG. 5D shows the two sets of channels on the disc;

[0072] FIG. 6A shows a fourth turbine embodiment in which the nozzles are shaped to create torque;

[0073] FIG. 6B shows another turbine embodiment in which the turbine is positioned within an internal passage of the core, along an axial extent thereof;

[0074] FIG. 6C shows yet another turbine embodiment in which the turbine which is positioned within an internal passage of the core, near one end thereof;

[0075] FIG. 7 shows a spiral rail arrangement for urging combined rotational and axial movement of nozzles, for use in various filter arrangements embodiments of the present invention; and

[0076] FIG. 8 shows a modified spiral rail arrangement having spacer wheels to prevent nozzles from contacting the filter screen.

[0077] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated within the figures to indicate like elements.

DETAILED DESCRIPTION

[0078] Attention is first drawn to FIGS. 1A to 1D illustrating at least some possible embodiments of a filter arrangement 10 of the present invention. In FIG. 1A filter arrangement 10 can be seen including an external body 12 enclosing a generally symmetrical balanced filter configuration, here embodied by a double filter configuration having two opposing filtration parts 101, 102 (first filter part 101 and second filter part 102). External body may be formed in some examples as two cover members.

[0079] Filter arrangement 10 has an inlet 14 through which incoming liquid (e.g. water) to be cleaned is received, an outlet 16 through which the relative cleaner liquid can exit after filtering out dirt/particles, and a flush valve 15 for flushing out liquid during a back- flushing cleaning action of the filter.

[0080] Attention is additionally drawn to FIGS. 1B and 1C illustrating respective assembled and exploded views of interiors of the filter parts 101, 102 showing screen filters 181, 182 (first screen filter 181 and second screen filter 182) and an embodiment of a cleaning system 20 of the present invention.

[0081] Cleaning system 20 in the shown example includes two opposing cleaning mechanism 201, 202 each configured to clean a respective one of the filter members 181, 182. The cleaning system 20 has a shaft-like hollow core 22 with suction nozzles 24 located there-along that are arranged to be in communication with an internal passage (see 221 visible in FIG. 3) of the shaft-like hollow core 22.

[0082] Cleaning system 20 includes in addition a turbine arrangement 23 located at a central region 25 of the core. Each of the opposing cleaning mechanisms 201, 202 is defined as including a respective opposing section of the shaft-like core 22 extending away from the central region 25 and the suction nozzles 24 associated with such section.

[0083] Cleaning mechanism 20 in addition includes a driving member 28 in this example embodied as a self-reversing screw 281 and blade nut-type configuration 282 (see also FIG. 1D). Also, cleaning mechanism 20 in seen including a flush chamber 29 located in-between and in connection with the screen filters 181, 182—with flush valve 15 being configured to communicate liquid out of the flush chamber, possibly to the ambient environment.

[0084] In an assembled state of the cleaning mechanism 20 and screen filters 181, 182 (see FIGS. 1B and 1D); the core's central region 25 and its turbine arrangement 23 are located within the flush chamber 29, with each cleaning mechanism 201, 202 extending through a respective one of the screen filters 181, 182.

[0085] During a filtering process (see FIG. 1D), liquid marked by the dotted lines enters filter arrangement 10 via inlet 14 to pass along an outer side of flush chamber 29 and flow along an interior face of the screen filters 181, 182. The liquid then passes in a general radial direction through the screen filters to their exteriors while being cleaned from dirt and leaving a so called “filtration cake” on the interior sides of the screen filters. The cleaned liquid then flows out of the filter arrangement 10 via outlet 16 as indicated by the dotted-dashed arrow lines.

[0086] Flush valve 15 may be controlled in various manners (e.g. manually, remotely, automatically, by sensing e.g. pressure, ow, etc.) to open or close and by that start or cease a cleaning action of the cleaning system.

[0087] In at least certain embodiments, opening flush valve 15 may expose the interior of the flush chamber 29 to low pressure, e.g. substantially ambient pressure, thus urging liquid to be sucked out of the pressurized environment within the filter arrangement via the suction nozzles 24. The dashed arrows in the enlarged section at the lower right-hand side of FIG. 1D illustrate this suction process applied to the inner side of the screen filters by the suction nozzles.

[0088] This in turn results in cleaning of the inner sides of the screen filters from the so-called “filtration cake” that is sucked away from the screen filters 181, 182. The liquid sucked in by the suction nozzles flows through the core's internal passage towards the flush chamber 15. The dashed arrows in enlarged section at the upper left-hand side of FIG. 1D illustrate such liquid sucked away from both screen filters 181, 182 arriving at the core's central region within the flush chamber.

[0089] Such cleaning operation by the cleaning system may be accompanied by movement of the cleaning mechanisms 201, 202 along the screen filters 181, 182. Such movements may be performed according to various embodiments of the invention by providing the cleaning systems with various types of driving members.

[0090] In the example shown in FIG. 1D, the driving member 28 (shown also in FIG. 2) is embodied as a self-reversing screw 281 and blade nut-type configuration 282. The blade nut-type configuration 282 may be arranged to initially match a first helical thread within screw 281 to urge axial movement in a first direction. Upon completing a scan of the filter screens along the first direction, the blade 282 can be made to pivot in order to match an opposing helical thread within screw 281 in order to urge advancement in an opposing axial direction.

[0091] In an aspect of the present invention, filter arrangements 10 may be provided with a so-called balanced cleaning system, by harnessing a possible generally symmetrical filter configuration, for example a double generally symmetrical filter configuration as here shown, for balancing out axial forces imposed upon the system during a cleaning operation.

[0092] The balancing of the cleaning system may be observed in certain cases, by exposure of the core to a pressure PO at its central region that may be substantially “zero”, while being exposed to substantially similar pressures P1 at both axial ends that act to substantially counter each other and by that, balance out forces (possibly axial forces) applied upon the core and consequently upon the cleaning mechanisms during a cleaning operation.

[0093] In certain cases (not shown), the ends of the cores may extend to outside of the body of the filter arrangement, and by that may be exposed to similar pressure P1 at ambient environment—again serving for balancing out forces from being applied upon the cleaning system during its operation.

[0094] Attention is drawn to FIGS. 1E and 1F illustrating embodiments of non-symmetrical filter arrangement 100, 110 exemplifying also a generally balanced filter configuration.

[0095] Both filter arrangements include a shaft-like hollow core 22 with suction nozzles 24 located there-along that are adapted to clean respective screen filters 183 of the filters.

[0096] The balancing of the cleaning system in these embodiments may be observed, by exposure of the core to substantially similar pressures P1 at both its axial ends, which act to substantially counter each other and by that balance out forces (possibly axial forces) applied upon the core and consequently upon the cleaning mechanisms during a cleaning operation.

[0097] Such exposure of the core to substantially similar pressures at both axial ends may be accomplished in one example by maintaining both axial ends of the core outside of e.g. the flush chamber of the filter where a pressure PO is lower, possibly substantially equal to that in the ambient environment.

[0098] Filter arrangement 100 (see FIG. 1E) exemplifies an embodiment where the inlet 14 and outlet 16 of the filter both are adjacent one axial end (first axial end) of the filter (here the upper end), while the filter's turbine arrangement 23, flush chamber 29 and flush valve 15 are located adjacent the opposing axial end (second axial end) of the filter. Filter arrangement 110 (see FIG. 1F) exemplifies an embodiment where the inlet 14, outlet 16, turbine arrangement 23, flush chamber 29 and flush valve 15 are all located adjacent one of the axial ends of the filter (here the upper end).

[0099] Attention is drawn to FIG. 3 illustrating an embodiment of a turbine arrangement 231. Turbine 231 includes a disc member 2311 and a plurality of channels 2312 that extend from the core's interior passage 221 to the outer periphery of the disc member. In this example, all the channels are similarly curved, and thus liquid flowing through turbine 231 is arranged to cause torque T in one direction about the core's axis urging the core to rotate in said direction about its axis.

[0100] Combining turbine 231 with an embodiment of a driving member 28 that includes a self-reversing screw 281 and blade nut-type configuration 282, may provide for back and forth movement of the cleaning mechanisms along the screen filters, with a turbine (such as 231) that can urge rotation only in one rotational direction about the core's axis. By shutting closed the flush valve 15, the cleaning process of the screen filters can be stopped.

[0101] Attention is drawn to FIG. 4A illustrating an embodiment of a turbine arrangement 232 that includes first and second disc members 2321, 2322. Each one of the disc members is formed, respectively, with a plurality of channels 23211, 23221 that extend from the core's interior passage to the outer periphery of each disc member, as seen in FIGS. 4AB and 4AC.

[0102] In this embodiment, the channels of the first disc member are arranged to form torque T1 that urges rotation of the core in a first rotational direction (R1) about its axis, while the channels of the second disc member are arranged to form torque T2 that urges rotation of the core in a second rotational direction (R2) about its axis that is opposite the first rotational direction.

[0103] Turbine 232 may be formed with a bridge 30 that connects the first and second disc members 2321, 2322 to each other. Bridge 30 can be formed with a slit 32 and the core can be formed with a pin 34 that is located within the slit, thus allowing turbine 232 to shift about the core between first and second extremities where the pin engages opposing ends of the slit.

[0104] At each one of the extremities, turbine 232 is arranged to expose channels (23211, 23221) within only a given one of its disc members (2321, 2322; respectively) to liquid flowing within the core's internal passage 221, thus urging rotation of the core according to the respective torque formed as liquid flows through the channels of the given disc member. In FIG. 4AA at the lower side of FIG. 4A, turbine 232 is shown at one of the extremities where the second disc member 2322 is in communication with the liquid flowing within the core. Therefore, the arrangement shown in this lower view of FIG. 4AA depicts rotation of the turbine and the core in direction R2.

[0105] A driving member (in this example of a uni-directional type, that requires change in rotational direction of a threaded portion to urge axial movements in opposing directions)—that can be fitted to the core—may dictate that rotation R2 of turbine 232 urges axial movement of the core and the cleaning mechanism(s) fitted thereto in direction X2 along the core's axis. The turbine and core may thus progress in direction X2 until a stop member 36 (possibly in the form of a notch or tooth) that is fixed to the turbine engages a right-hand side barrier 38R (or a structure fitted thereupon) of the flush chamber.

[0106] Implementing turbine 232, e.g., in a generally symmetrical filter configuration, such as that shown in FIGS. 1A to 1D, may result in movements in cleaning mechanisms 201, 202 being assisted by a driving mechanism (as mentioned above). Implementing turbine 232 e.g. in a generally non-symmetrical filter configuration, such as that shown in FIGS. 1E and 1F, may result in movements in this filter's cleaning mechanism being assisted by a uni-directional driving mechanism such as 2800, 2810 shown in these figures.

[0107] Attention is drawn to FIG. 4AD in the upper most view in FIG. 4A to address a general aspect of the present invention, which relates to formation of two separate passageways within the internal passage of the shaft-like hollow core. In this shown example, internal passage 221 is divided into two such separate passageways 2211, 2212 by provision of a barrier 77 within the internal passage into—here in a location along a section of the shaft-like hollow core that is positioned generally within the flush chamber 29 of the filter.

[0108] Self-cleaning of screen filters, that are based on suction nozzles in order to evacuate debris (filtration cake) from the screen's inner side, rely on suction forces at the nozzle tips in order to facilitate efficient suction and cleaning of the filter face.

[0109] Higher suction force, or suction speed, usually translates into improved suction and superior cleaning capabilities. Suction force, or suction speed at the nozzles may be a function of the nozzles area (sum of nozzles) and the flush water flow rate (e.g., ‘nozzle suction velocity’) may be generally equal to ‘nozzle area’/‘suction water flow rate’.

[0110] Large screen areas typically require more suction nozzles (since each nozzle can cover only a limited area of the screen), and thus the total nozzle area increases. This in turn, may require higher flush flow rates in order to maintain the same suction speed at the nozzles.

[0111] Increasing the flush flow rate in at least certain cases may be less recommended due to several reasons: It may require a larger and more expensive pump to support the system, higher energy (pump) usage during flush, the amount of water that is flushed out of the system increases, larger pressure losses within the flush system, and possibly large and significant flow interference at the irrigation flow rate during flush.

[0112] An example relevant, inter alia, to the last-mentioned reason may be the following. If irrigation requires e.g. 100 m{circumflex over ( )}3/Hour, and flush requires 30 m{circumflex over ( )}3/Hour—that means that during a cleaning action about 30% of the flow may be diverted to be flushed out of the filter arrangement. If on the other hand the flush flow rate were to be less, e.g., about half of that in the discussed example, i.e. about 15 m{circumflex over ( )}3/Hour, then only about 15% of the water may end up being diverted to be flushed out of the total flow.

[0113] Thus, in at least certain embodiments where a filter arrangement includes more than one filtration element (e.g., screen), selective flushing of each filtration element may be advantageous in order to avoid the above-mentioned disadvantages that may occur if the flow of water being flushed were to be larger. The filtration arrangement in FIGS. 1A-1D, which includes two screen filters 181, 182 is an example of a filtration arrangement where such formation of two separate passageways within the internal passage of the shaft-like hollow core may be suitable.

[0114] In embodiments discussed herein where filtration arrangements include a single, shared flushing mechanism, an arrangement that comprises presence of a barrier dividing the internal passage through the shaft-like hollow core into separate passage members 2211, 2212 may be suited to address the above.

[0115] Although provision of two separate passageways has been exemplified in the figures with respect to turbine arrangement 232, it is noted that formation of such two separate passageways may be envisioned in other filtration arrangements and/or in conjunction with other turbine arrangements, such as turbine 23 seen in FIG. 1B, turbine 231 seen in FIG. 3, turbine 2320 seen in FIG. 4B, turbine 233 seen in FIG. 5 (or the like).

[0116] Engagement between stop member 36 and (in the discussed example) the right-hand side barrier 38R (or a structure fitted thereupon), may urge turbine 232 to start rotating in an opposing direction. This may occur by momentarily stopping the rotation of the turbine in direction R2, while the core continues due to momentum to rotate in direction R2 thus shifting pin 34 to engage the opposing extremity of slit 32.

[0117] At this opposing extremity, turbine 232 is arranged to bring the channels formed within the first disc member 2321 into communication with liquid flowing through the core (while blocking the flow channels set at disc 2322)—thus urging rotation of the turbine 232 in direction R1 about the cores' axis with combined axial movement in direction X1.

[0118] This new combined movement (R1, X1) of the core and the cleaning mechanism(s) fitted thereto may urge a cleaning scanning action of the screen filter(s) in an opposing direction. This may continue until a stop fitted to an opposing side of the turbine engages a left-hand side barrier 38L of the flush chamber—thus potentially igniting a repeated movement according to R2, and X2. By shutting the flush valve 15, the cleaning process of the screen filters can be stopped.

[0119] Attention is drawn to FIGS. 4B and 4C illustrating a turbine embodiment 2320 generally similar to 232, while mainly differing from it in its mechanism for altering rotational direction when engaging a barrier of its flush chamber. In this embodiment, each barrier (38R, 38L) of the flush chamber may be fitted at its respective inner side 39 facing into the flush chamber with a lever member 37 which is pivoted to the inner side.

[0120] With attention specifically drawn to FIG. 4C, the operation of the proposed mechanism of this embodiment will be described, while starting at the upper right-hand side image of this figure (FIG. 4CA)—and then proceeding to subsequent images in this figure according to the ‘dashed’ arrow.

[0121] The upper right-hand side image of FIG. 4CA illustrates an instance where a stop member 36 on a side of the turbine rotating in direction R2—reaches a position proximal to a barrier's inner side 39—and engages the lever member 37 on that inner side.

[0122] The biased lever member 37 being pivoted by stop member 36 can be seen in the subsequent image (upper left image of FIG. 4CB) engaging a raised bulge 35 that is fixed to the shaft-like hollow core 22. The turbine still rotating in direction R2 continues to apply rotation force via lever 37 against bulge 35 thus urging the core 22 to also rotate in direction R2.

[0123] This rotation of the core 22 in direction R2 proceeds until pin 34 that is also fixed to the core is shifted to a position where it engages an opposing extremity within slit 32 as seen in FIG. 4CC. In that position, the channels formed within the first disc member 2321 are brought into communication with liquid flowing through the core—thus urging rotation of the turbine 2320 in the opposing direction R1 about the core's axis (see lower right-hand side image of FIG. 4CD) with possible combined axial movement in direction X1 due to interaction with a driving member (such as a uni-directional type, that requires change in rotational direction of a threaded portion to urge axial movements in opposing directions).

[0124] Attention is drawn to FIG. 5 illustrating yet a further embodiment of a turbine arrangement 233. Turbine 233 includes a disc member 2331 formed in this example with two sets of channels 23311, 23312 that extend from the core's interior passage 221 to the outer periphery of the disc member, as seen in FIGS. 5A and 5D. Each one of the sets of channels 23311, 23312 is arranged to cause torque about the core's axis in a different rotational direction. As such they are configured for urging rotation about the core's axis in opposing rotational direction R1, R2.

[0125] An inner side of disc member 2331 is formed with a groove 40 that engages a bulge 42 formed on the core, as seen in FIGS. 5B and 5C. Thus, the engagement between the groove 40 and bulge 42 allows turbine 233 to slide upon the core between two extremities, wherein at each extremity one of the sets of channels 23311, 23312 is exposed to liquid flowing through the core.

[0126] When a respective one of the sets of channels is exposed to liquid arriving from the core, the turbine is urged to rotate about the core's axis according to the respective torque formed by said channels.

[0127] A driving member fitted to the core may dictate, e.g., that rotation R1 of turbine 233 urges axial movement of the core and the cleaning mechanism(s) fitted thereto in direction X1 along the cores' axis. The turbine and core may thus progress in direction X1 until engaging a right-hand side barrier 38R of the flush chamber.

[0128] This engagement may urge the turbine to slide towards its opposing extremity upon the core, as the core continues due to momentum to advance in direction X1. At this opposing extremity, turbine 233 is arranged to bring the other set of channels into communication with liquid flowing through the core—thus urging rotation of the turbine 233 in direction R2 about the cores' axis with combined axial movement in direction X2.

[0129] This new combined movement (R2, X2) of the core and the cleaning mechanisms fitted thereto may urge a cleaning action of the screen filters 181, 182 in an opposing direction. This may continue until the turbine engages a left-hand side barrier 38L of the flush chamber—thus potentially igniting a repeated movement according to R1, and X1. By shutting closed the flush valve 15, the cleaning process of the screen filters can be stopped.

[0130] Attention is drawn to FIGS. 6A to 6C illustrating various other turbine embodiments that may be envisioned. In FIG. 6A, an embodiment is shown where the nozzles themselves may be used for urging torque and consequently rotational movement to the core. This may be accomplished by suitably curving the nozzles as then extend radially outwardly away from the core—so that they apply the required torque as liquid is sucked in by the nozzles during a cleaning operation.

[0131] In FIG. 6B, an embodiment is shown where an axially extending turbine may be chosen to be fitted within an axial portion of the internal passage of the core. Liquid urged to flow through the core during a cleaning operation and flowing passed a helical path defined by this turbine can be designed to apply suitable torque for urging rotation of the core.

[0132] In FIG. 6C, an embodiment is shown where a turbine segment may be chosen to be fitted adjacent an end of the internal passage of the core, here an end proximal to the flushing chamber of the filter. Liquid urged to flow through the core during a cleaning operation and flowing passed a helical path defined by this turbine segment can be designed to apply suitable torque for urging rotation of the core.

[0133] Attention is drawn to FIGS. 7 and 8 illustrating an aspect of the present invention directed at an alternative arrangement for urging combined rotational and axial movements of a cleaning mechanism along a screen filter. In an embodiment, a filter arrangement may be provided with a helical rail 500 formed upon an inner side of its screen filter.

[0134] A filter arrangement including any type of measure for urging rotation of its cleaning mechanism about the core's axis, may be guided to assume combined rotational and axial movement by helical rail 500. It is noted that such measures for urging rotation may include any one of the turbine examples discussed herein above, while also any other techniques such as an external motor coupled to the filter's core (and the like).

[0135] Suction nozzles 24 of a cleaning mechanism aimed at removing “filtration cake” from an inner side of the screen filter may be guided to move in an axial direction according to a pitch of the helix.

[0136] Such positioning of a tip of a suction nozzle closely between segments of the helical rail may assist in directing suction in a radial direction towards the inner side of the filter screen. Thus, the helix segments located on both sides of the suction tip may substantially block liquid from being sucked into such nozzles from lateral sides where the targeted “filtration cake” is substantially absent.

[0137] The lower views in FIG. 7 illustrate optional use of wheel members 501, 502 fitted to each nozzle and adapted to engage rail 500 during a cleaning action of the screen filter. Provision of such wheel members may be useful in ensuring that a tip of a nozzle is maintained at desired distance from the screen of the filter suitable for performing its intended cleaning action, while avoiding an intended contact with the screen of the filter that may damage the screen.

[0138] In the description and claims of the present application, each of the verbs, “comprise” “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements or parts of the subject or subjects of the verb.

[0139] Furthermore, while the present application or technology has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and non-restrictive; the technology is thus not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art and practicing the claimed technology, from a study of the drawings, the technology, and the appended claims.

[0140] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0141] The present technology is also understood to encompass the exact terms, features, numerical values or ranges etc., if in here such terms, features, numerical values or ranges etc. are referred to in connection with terms such as “about, ca., substantially, generally, at least” etc. In other words, “about 3” shall also comprise “3” or “substantially perpendicular” shall also comprise “perpendicular”. Any reference signs in the claims should not be considered as limiting the scope.

[0142] Although the present embodiments have been described to a certain degree of particularity, it should be understood that various alterations and modifications could be made without departing from the scope of the invention as hereinafter claimed.