AU2009245820A1 - Filter assembly - Google Patents

Description

1 FILTER ASSEMBLY Technical Field This invention relates to a filter assembly and in particular to a liquid filter assembly. The present invention has particular application as a filter assembly for 5 swimming pools, spa pools or hot tubs but may be applied to use in filtering water or liquid in other water or liquid reservoirs. Background Art Filter assemblies for swimming and spa pools are of various designs and include a pump, a filter which may comprise a sand filter, diatomaceous earth filter or cartridge 10 filter, and various valves for controlling the flow of liquid from the pump to the pool. Further plumbing pipes are connected to the suction side of the pump and to one or more skimmer boxes set within the wall of a pool. Further pipes are connected to the outlet of the filter for return of filtered water to the pool usually through a series of nozzles in the pool wall. Installation of the pipes can often be difficult and require the placement of 15 large lengths of usually plastics pipe in the ground after the ground is excavated to receive the pool or for pool construction. Consequently such pipes can be damaged or broken during pool construction or installation. Furthermore, it is not uncommon for pipes located within the ground to break or pull free of plumbing connections over a period of time due for example to ground subsidence or movement. 20 A further disadvantage of conventional filter assemblies arises because the filter assemblies including their pumps are installed above ground. As a result, substantial noise can be generated. This often necessitates the installation of this type of filter assembly in an above-ground enclosure. Because of the size of some filters such as sand filters, the enclosure has to be of a significant size which therefore adds to installation 25 costs. To reduce noise, filter assemblies can be installed at a distance from living areas say of a domestic dwelling. This however necessitates the installation of connecting pipes of extended length which results in the disadvantages referred to above. Yet a further disadvantage of conventional filter assemblies is that the pump has to be of a capacity to create a sufficient head enable water to be pumped from the pool 30 and through the filter assembly before return to the pool. Pumps for this purpose therefore have to be of significant power rating and supplied with mains power. As a result power consumption of a pool pump is high and as a result of increasing electricity 2 supply costs, running costs are becoming increasingly high as pumps need to be run for a substantial number of hours for effective filtering of the full volume of a pool. It is an object of the present invention to overcome or at least ameliorate one or more of the above disadvantages of the prior art. 5 Summary of the Invention The present invention provides in one aspect although not necessarily the broadest aspect, a filter assembly for a liquid reservoir, said filter assembly comprising hollow housing means defining at least one liquid chamber, an inlet to said housing means and adapted to communicate in use with liquid in the liquid reservoir adjacent the normal liquid 10 level therein, an outlet for filtered liquid from said housing means below said inlet, liquid filtering and/or treating means within said at least one chamber, and pump means in said chamber for pumping liquid from said inlet through said filtering and/or treating means to said outlet. The term "liquid reservoir" as used herein and throughout the specification includes 15 swimming and spa pools and any other water or liquid holding reservoir. The inlet to the housing means suitably comprises a throat which communicates with the liquid reservoir. Preferably the throat is adapted to be located or set within a wall of the liquid reservoir. The liquid filtering and/or treating means suitably includes a main filter and the 20 pump means includes an outlet for supplying liquid to the main filter. The main filter most suitably comprises a cartridge filter and the outlet of the pump means is adapted to direct liquid circumferentially of the filter. The filter however may be any other form of filter. Preferably the outlet of the filter assembly communicates with the main filter on the downstream side of the main filter. Preferably the main filter is hollow and the outlet of the 25 filter assembly is adapted to communicate with the hollow interior of the main filter. Preferably the liquid filtering and/or treating means further comprises a filter basket between the inlet and the pump means. Preferably the pump means is located below the filter basket and is operative to draw in water through the filter basket The liquid filtering and/or treatment means may also include means for sterilising 30 or sanitising water or liquid in the at least one chamber. Preferably the outlet of the filter assembly is connectable to a duct which is adapted to communicate with the liquid reservoir through the wall thereof. Most preferably the housing means includes a pair of liquid chambers which 3 contain the pump means and liquid filtering and/or treatment means. Preferably the pair of liquid chambers is arranged in a side by side attitude. Preferably a first one of the chambers carries the pump means and the second chamber carries the main filter. Preferably the pump means is arranged to pump liquid from the first 5 chamber to the second chamber for filtering by the main filter. Preferably the first chamber communicates with the throat. Preferably the throat communicates with an upper portion of the first chamber. Preferably the throat is arranged between the respective chambers and communicates with an upper chamber above the respective chambers. Preferably the first chamber communicates with the upper chamber. 10 Preferably closure means are provided to prevent communication between the second chamber and the upper chamber. Such closure means may comprise a removable closure member or cap at the upper end of the second chamber. Preferably means are provided to secure the removable cap to the upper end of the second chamber to define a substantially close filter chamber in which the main filter is located. Preferably the 15 securing means comprises an elongated member extending longitudinally of the second chamber. Preferably the upper chamber is defined by an upper hollow housing from which the throat extends. Preferably the upper housing is accessible through a removable hatch or cover which is adapted to closed an upper access opening into the housing. Preferably the 20 hatch or cover is detachable from the upper housing to provide access to the upper chamber and the first and second chambers. Preferably the filter basket is provided at an upper portion of the first chamber. Preferably the filter basket is accessible through the access opening. Preferably a transfer passage is provided between the first and second chambers 25 which is adapted to be aligned with the outlet of the pump means when the latter is located within the first chamber. Preferably the pump means is detachable from the first chamber. Preferably the pump means is suspended beneath the filter basket. The pump means may comprise any form of pump which may operate when submerged. Typically the pump comprises a centrifugal pump. 30 Preferably a further filter basket is located in the base of the second chamber and the main filter is adapted to sit within the filter basket. The further filter basket is adapted to collect materials displaced form the further filter basket. Preferably the first and second chambers are closed at their lower end by a common 4 end member or plate. Preferably the outlet from the filter assembly is provided in the end plate. Preferably the outlet is provided in alignment with the second chamber and preferably centrally of the second chamber. Brief Description of the Drawings 5 The following drawings and description relating thereto are provided to enable an embodiment of the invention to be readily understood and put into practical effect. It will be appreciated however that embodiment is given by way of example of the invention only and is not to be regarded as limiting the scope of the invention as summarized above. In the drawings: 10 Fig. 1 is an isometric view from the front of a filter assembly according to an embodiment of the present invention; Fig. 2 is an isometric view of the filter assembly from the rear and above with the top hatch removed and with the chambers reversed; Fig. 3 is an isometric view from below showing the filtering components of the 15 filter assembly; Fig. 4 is a schematic cross- sectional front view of the filter assembly; Figs. 5 is a schematic cross-sectional side view of the filter assembly; Fig. 6 is a schematic cross-sectional opposite side view of the filter assembly installed within a reservoir wall; and 20 Fig. 7 is an isometric half sectional view of the filter assembly. Detailed Description of the Preferred Embodiment Referring to the drawings and firstly to Figs. 1 and 2, there is illustrated a filter assembly 10 according to an embodiment of the present invention designed in this case to be associated with an in-ground swimming pool and which can be set in or adjacent a 25 wall of the swimming pool as described further below. The filter assembly 10 includes a housing assembly 11 which comprises a pair of pair of upright cylindrical hollow housings 12 and 13 which are arranged side-by-side and interconnected or integral with each other. The housings 12 and 13 define respective hollow cylindrical chambers 14 and 15 and may be manufactured integrally for example by rotational or injection 30 moulding or may be separately manufactured in a moulding process and subsequently interconnected. A common planar end member or plate 16 shown also in Fig 3 and Figs. 4 to 6 is provided at the lower end of the housing assembly 11 to close the lower ends of each 5 chamber 14 and 15. A common hollow upper housing 17 is provided at the upper end of the housing assembly 11 to close the upper ends of each chamber 14 and 15 and defines an internal hollow space or upper chamber 18 above the chambers 14 and 15. A hollow rectangular inlet throat 19 similar to the throat of a conventional skimmer box is located 5 centrally relative to the side-by-side housings 12 and 13 and extends outwardly therefrom, the throat 19 being adapted to penetrate the wall of the swimming pool and defining an inlet for water to be filtered. The throat 19 as with conventional skimmer boxes includes a buoyant weir door 20 which is hingedly mounted adjacent its lower edge to opposite side walls 21 of the throat 19. The weir door 20 as is conventional is 10 normally in an upright attitude when the filter assembly 10 is not operating but pivots to at least a partially open position to allow entry of water and small materials floating on the surface of the water to enter the throat 19 and the chamber 18 of the hollow housing 17 rearwardly of the throat 19. The housing 17 includes a top wall 22 which is substantially coplanar with the 15 top wall of the throat 19 and a centrally located rectangular opening 23 in the top wall 22 provides access to the chamber 18 of the housing 17. The opening 23 is surrounded by an upstanding peripheral wall 24 and the opening 21 can be closed by means of a removable hatch 25 which may sit on and be supported on the peripheral wall 24 and extend into the opening 23 as is apparent in Figs 4 to 6. 20 The housing 12 which is open at its upper end to the chamber 18 in the hollow housing 17 includes at that upper end, an inwardly extending annular rib 26 which defines a support for the upper peripheral rim 27 of a leaf or debris basket 28 (see also Fig. 3) which is of a conventional mesh-like construction. A disc- shaped pump support member 29 seats and is supported peripherally on a 25 further inwardly extending annular rib 30 of the housing 12 located below the leaf basket 28. The support member 29 is provided with a series of circumferentially extending openings 31 through which water can flow without impediment. An electric motor operated pump 32 is mounted to the support member 29 by downwardly extending support rods 33 so as to be suspended from the member 29. The pump 32 which 30 typically comprises a centrifugal pump has its inlet 34 on its lower side and a tangentially extending outlet duct 35. A transfer duct 36 is mounted to and penetrates the walls of the respective adjacent housings 12 and 13 and is oriented in a substantially tangential direction relative to the housing 13. The transfer duct 36 is aligned with and 6 connectable to the pump outlet duct 35 such that liquid flow from the pump 32 is directed substantially tangentially into the interior chamber 15 of the housing 13. Alternatively the pump outlet duct 35 may simply abut the end of the transfer duct 36 within the chamber 14 5 A water treatment device 37 as shown in dotted outline in Fig. 4 is provided to treat water flowing through the chamber 14 for example by sanitizing or sterilizing the water. The device 37 may be located in an apertured housing 38 through which water may pass for exposure to the water treatment device 37. Typically the water treatment device 37 is an electrically operated device and may be detachably plugged into a power 10 supply outlet or socket 39 in a side wall of the housing 12 with suitable water sealing provided. The water treatment device 37 may comprises a salt chlorination cell, an ozone generator, a UV treatment unit or combinations of one or more of these devices. The water treatment device 37 however may comprise any other form of water treatment device or sanitizer. 15 The chamber 15 comprises a filter chamber and an outlet 40 from the chamber 15 is provided in the end member 16 and centrally relative to the chamber 15. The outlet 40 may comprise a spigot or socket for engagement by an outlet duct as described further below. The end member 16 includes a wall portion 41 which extends across the outlet 40 and which is provided with apertures 42 therein such as to allow liquid to pass 20 through the outlet 40 Located within the chamber 15 is a filter 43 which in this embodiment is a cartridge filter which is of elongated hollow cylindrical form. An elongated filter retaining member or rod 44 is secured releasably to and extends centrally from the wall portion 41 of the end plate 16 and upwardly through the hollow centre of the filter 43. 25 The upper end of the rod 44 is provided with an annular member 45 which serves as a handle. The rod 44 has an upper threaded end 46 engageable by a hand operated screw such as a thumb screw 47. The lower end of the rod 44 may also be threaded for engagement with a nut on the lower side of the wall portion 41 or alternatively with a threaded bore in the wall portion 41. A disc-shaped cover 48 is provided at the upper 30 end of the housing 13 and includes a central opening for receipt of the threaded end 46 of the rod 44, the cover 48 being of a diameter which is substantially the same as the diameter of the chamber 15. The cover 48 includes an annular skirt 49 centrally on its lower side for stiffening the centre of the cover 48. When the thumb screw 47 is 7 engaged with the protecting threaded end 46 of the rod 44, the cover 48 is forced downwardly onto the upper end of the filter 43 to clamp the filter 43 directly or indirectly onto the end member 16. The cover 48 also closes and substantially seals the upper end of the chamber 15. 5 A bucket-shaped filter basket 50 may also be provided at the lower end of the chamber 15 and the lower end of the filter 43 is received within and seats within the basket 50. The basket 50 includes an outer cylindrical wall 51 and base 52 substantially formed of a mesh material and the base 52 is centrally aperture so that the rod 44 can extend therethrough. 10 The filter assembly 10 is installed on or in a wall 53 of a swimming pool 54 in the case of a concrete pool, usually during construction of the pool, such that the throat 19 penetrates the wall 53 the swimming pool at the normal level of water in the pool as shown in Fig. 6. In this position, the hatch 25 is substantially flush with the top of the pool wall 53 and coping tiles 55 may be provided on the top of the pool wall 53 and top 15 of the hatch 25 so as to present a seamless appearance. A return duct or pipe 56 is connected to the outlet 40 and penetrates an adjacent portion of the pool wall 53. The return duct or pipe 56 however may penetrate the pool wall 53 at a location remote from the assembly 10. As the housings 12 and 13 extend below the throat 19, the chambers 14 and 15 will always be flooded with water 57 from the pool 54 provided the throat 19 20 is always above the level of the water 57 in the pool 54. When the pump 32 is operated, the suction pressure created by the pump 32 will draw in water 57 from the pool 54 through the throat 19 causing the weir door 20 to open and water to be drawn into the chamber 14 through the filter basket 28 which will trap any floating debris such as leaves or larger material which are allowed to enter the 25 throat 19. Water however will not enter the chamber 15 via the throat 19 as it is closed by the cover 48. Water filtered through the leaf basket 28 will be sucked downwardly towards the pump inlet 34 as indicated by the arrows A in Fig. 4. Water in the lower region of the chamber 14 will also pass into the housing 38 of the water treatment device 37 as 30 indicated by the arrows B so as to be exposed to the sanitizing or sterilizing effect of the device 37 for example to salt water chlorination. Water drawn into the pump inlet 34 will be pumped out through the pump outlet 35 and through the aligned transfer duct 36 and into the chamber 15. The water will be 8 directed in a tangential direction as indicated by the arrow C and flow generally circumferentially around the filter 43 as indicated by the arrows D. This will cause larger particles to be separated and fall down to be trapped in the basket 50. Water will also pass through the wall of the filter 43 to be fine filtered as indicated by the arrows E 5 in Fig. 4 and pass into the hollow interior of the filter 43 and then into the return duct 56 via the outlet 40 as indicated by the arrow F and be returned as filtered and treated water to the pool 54. Access to the components of the filter assembly 10 may be readily had by lifting of the hatch 25 (and coping tile carried thereby). This will provided access to the leaf 10 basket 28 which may be readily removed through the opening 23 for cleaning. When the basket 28 is removed, the pump 32 and attached support member 29 may also be removed for servicing and also to provide access to the water treatment device 37 which may require cleaning. This may be simply detached from the socket 39 for cleaning or replacement. 15 Similarly removal of the hatch 25 will provide access to the housing 13 and the filter 43 contained therein. For removal of the filter 43, the thumb screw 47 is unscrewed which allows the cover 48 to be removed and allow the filter 43 to be grasped and raised from the chamber 14 for cleaning. Any materials which drop from the wall of the filter 43 will drop and be collected in the basket 50 so that it will not re-enter the 20 pool 54 and the basket 50 can also be removed from the housing 13 to allow the material collecting in the basket 50 to be discarded. The water treatment device 37 may instead of being located in the chamber 14 be located in the chamber 15 for example in the interior of the filter 43 as shown in dotted outline in Fig. 6 such that water is treated before exiting through the return duct 56. In 25 an alternative arrangement, the water treatment device 37 may be located in the chamber 18 such that water drawn in through the throat 19 is subject to treatment prior to passing through the filter 43. In other arrangements, the filter assembly 10 may be provided without a water treatment device 37 with water treatment carried out separately. 30 For larger pools, a number of filter assemblies 10 may be installed at different locations around the periphery of the pool. Each filter assembly 10 thus can operate independently which will assist in the circulation capacity of the pool.

9 Because the components of the filter assembly 10 are located in a below-ground location, noise generation is very low as compared to above ground systems. Typically the pump 32 is a low voltage pump such as a 12, 24 or 32 volt pump which improves safety in the region around the pool. The pump 32 is typically 5 constructed of a material which will resist corrosion as it is always submerged within water of the liquid reservoir. A preferred material for the pump 32 is stainless steel. The pump 32 suitably is a centrifugal pump however other forms of submergible pump however may be used. The filter assembly of the invention is particularly suitable for use with in-ground 10 swimming pools, spas and hot tubs however it may be used with other liquid reservoirs such as water tanks or for filtering other bodies of liquid. The filter assembly can be installed within minimum plumbing and therefore the risks of water leakage are minimised. Installation time and therefore costs is also minimised. The terms "comprising" or "comprises" as used throughout the specification and 15 claims are taken to specify the presence of the stated features, integers and components referred to but not preclude the presence or addition of one or more other feature/s, integer/s, component/s or group thereof. Whilst the above has been given by way of illustrative embodiment of the invention, all such variations and modifications thereto as would be apparent to persons 20 skilled in the art are deemed to fall within the broad scope and ambit of the invention as herein defined in the appended claims. 25 30

Claims (26)

1. A filter assembly for a liquid reservoir, said filter assembly comprising hollow housing means defining at least one liquid chamber, an inlet to said housing means and 5 adapted to communicate in use with liquid in the liquid reservoir adjacent the normal liquid level therein, an outlet for filtered liquid from said housing means below said inlet, liquid filtering and/or treating means within said at least one chamber, and pump means in said chamber for pumping liquid from said inlet through said filtering and/or treating means to said outlet. 10

2. A filter assembly as claimed in claim 1 wherein said inlet to the housing means comprises a throat.

3. A filter assembly as claimed in claim 2 wherein said throat is adapted to be located 15 or set within a wall of the liquid reservoir.

4. A filter assembly as claimed in any one of claims 1 to 3 wherein said liquid filtering and/or treating means comprises a main filter and wherein said pump means includes an outlet for supplying liquid to the main filter. 20

5. A filter assembly as claimed in claim 4 wherein said main filter comprises a cartridge filter and wherein the outlet of the pump means is adapted to direct liquid circumferentially of the filter. 25

6. A filter assembly as claimed in claim 4 or claim 5 wherein the outlet of the filter assembly communicates with the main filter on the downstream side of the main filter.

7. A filter assembly as claimed in claim 6 wherein the main filter is hollow and the outlet of the filter assembly is adapted to communicate with the hollow interior of the main 30 filter.

8. A filter assembly as claimed in any one of the preceding claims wherein said liquid filtering and/or treating means comprises a filter basket between the inlet and the pump 11 means.

9. A filter assembly as claimed in claim 8 wherein the pump means is located below the filter basket and is operative to draw in water from the inlet through the filter basket 5

10. A filter assembly as claimed in any one of the preceding claims wherein the liquid filtering and/or treatment means include means for sterilising or sanitising liquid in the at least one chamber. 10

11. A filter assembly as claimed in any one of the preceding claims wherein the outlet of the filter assembly is connectable to a duct which is adapted to communicate with the liquid reservoir through a wall thereof

12. A filter assembly as claimed in claim 1 wherein said housing means includes a pair 15 of liquid chambers which contain the pump means and liquid filtering and/or treatment means.

13. A filter assembly as claimed in claim 12 wherein said pair of liquid chambers is arranged in a side by side attitude. 20

14. A filter assembly as claimed in claim 12 or claim 13 wherein a first one of the chambers carries the pump means and the second chamber carries a main filter of said liquid filtering and/or treatment means. 25

15. A filter assembly as claimed in claim 14 wherein the pump means is arranged to pump liquid from the first chamber to the second chamber for filtering by the main filter.

16 A filter assembly as claimed in any one of claims 12 to 15 wherein said inlet comprises a throat and wherein the first chamber communicates with the throat. 30

17. A filter assembly as claimed in claim 16 and including an upper chamber between said first and second chambers, said upper chamber communicating with said throat and wherein the first chamber communicates with the upper chamber. 12

18. A filter assembly as claimed in claim 17 wherein closure means are provided to prevent communication between the second chamber and the upper chamber. 5

19. A filter assembly as claimed in claim 18 wherein said closure means comprises a removable closure member or cap at the upper end of the second chamber.

20. A filter assembly as claimed in claim 19 and including means for securing the removable cap to the upper end of the second chamber to define a substantially close filter 10 chamber in which the main filter is located.

21. A filter assembly as claimed in any one of claims 17 to 20 wherein said upper chamber is defined by an upper hollow housing said upper housing being accessible through a removable hatch or cover which is adapted to closed an upper access opening 15 into the housing.

22. A filter assembly as claimed in any one of claims 14 to 21 wherein a transfer passage is provided between the first and second chambers which is adapted to be aligned with an outlet of the pump means when the latter is located within the first chamber. 20

23. A filter assembly as claimed in any one of claims 14 to 22 wherein a further filter basket is located in the base of the second chamber and the main filter is adapted to sit within the filter basket. 25

24. A filter assembly as claimed in any one of claims 12 to 22 wherein a filter basket is provided at an upper portion of the first chamber.

25. A filter assembly as claimed in any one of the preceding claims wherein the first and second chambers are closed at their lower end by a common end member or plate. 30

26. A filter assembly substantially as hereinbefore described with reference to the accompanying drawings.