AU2007221311A1

AU2007221311A1 - A filter device

Info

Publication number: AU2007221311A1
Application number: AU2007221311A
Authority: AU
Inventors: Paul Stefou
Original assignee: STEFOU FABRICATION Pty Ltd
Current assignee: STEFOU FABRICATION Pty Ltd
Priority date: 2006-10-03
Filing date: 2007-09-28
Publication date: 2008-04-17

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 00

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ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: A FILTER DEVICE Applicant: Stefou Fabrication Pty Ltd The following statement is a full description of this invention, including the best method of performing it known to me: 1 W:\DELILAHDDMCOMPLETEmB12943-cap foms doc A FILTER DEVICE (-i 4 The present invention relates broadly to a filter device. More specifically, the invention relates to a storm water filter device and will be herein generally 0 5 described in that context. However, it is to be appreciated that the invention

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may have other applications.

Generally speaking, storm water run-off in cities and other urban environments is directed or collects in street and roadway gutters, whereupon it flows along the gutters until it reaches a storm water drain inlet. Storm water drain configurations are many and varied, but generally include a system of (-i underground pipelines for conveying storm water to a discharge outlet. Outlets typically are in the form of a waterway such as a river, or the sea. Storm water drain inlets typically include a pit or other some other cavity located beneath the surface of the ground, which is in fluid communication with both the upstream gutters and the downstream pipeline system. Drain inlets are generally covered with a cover, which can be removed to provide access to the inlet if required.

One problem associated with storm water drains is that storm water often transports a large amount of litter and solid waste. Consequently, storm water drains tend to accumulate large amounts of litter and solid waste, including plant matter such as leaves, twigs and branches, soil and other particulate matter such as sand, and man made litter such as plastic bottles, wrappers and packaging. The accumulation of such material in drains can lead to blockages, or is discharged into waterways or the sea, thereby creating pollution and other environmental problems.

It would therefore be desirable to provide some means for addressing the above described problems inherent in existing storm water drains.

According to one broad aspect of the present invention, there is provided a filter device for removing litter and solid waste from storm water entering a storm water drain. The filter device is adapted for location within a pit at an inlet to a storm water drain. The filter device includes a filter bag, and the filter bag W \DELILAH DDM\COMPLETE\A FILTER DEVICE doc 2 includes a wall structure defining a catchment space for collecting and retaining Slitter and solid waste from the storm water as it enters the drain. The filter bag (-i Sincludes an opening for the passage of storm water into the catchment space.

C The wall structure of the filter bag is porous, the porous wall structure permitting (3O 00 5 the flow of storm water there through, but substantially preventing the flow of solid litter and waste of a specified size there through. The filter device further includes a filter bag support for supporting the filter bag within the pit. The support includes a support surface for supporting the filter bag thereon and at least one mount for mounting the support in position within the pit.

The wall structure of the filter bag may be manufactured from any suitable material. In one form, the filter bag is manufactured at least substantially from fabric. In a more preferred form, however, the wall structure of the filter bag is manufactured at least substantially from a synthetic material and, more preferably from a non-woven synthetic material. In one suitable form, the synthetic material has a pore size in the range of approximately 90pm to 120pm (using the AS3706.7-90 test method). In a more preferable form, the material has a pore size range of approximately 100pm to 110pm. Such a pore size range enables the bag to desirably collect at least a portion of litter and solid waste in the form of silt, sand and other particulate matter that may be present in the storm water entering the pit, thereby preventing such matter from entering, collecting and potentially blocking the storm water drain. It also prevents at least a portion of the silt, sand and other particulate matter present in the storm water fouling or otherwise damaging the environment at the drain exit.

Possible bag wall structure materials include any of the bidim® range of geotextile materials sold by Geofabrics Australasia Pty Ltd, particularly the A12, A14, A19 and A24 geotextiles.

The wall structure may adopt any suitable size and shape, with the size and shape being, at least in part, dependent upon the size and shape of the pit into which the filter device is to be fitted.

W\DEIILAH\DDM\COMPLETE\A FILTER DEVICEdc It is envisaged that, in a preferred form, the wall structure may include at least Sone bag wall. More preferably, the bag includes a base wall (or simply 'base') e and one or more side walls extending upwardly from the base wall to define the a) Ccatchment space. The upper edges of the side walls may define the bag oo 00 5 opening.

The base wall may be, for example, circular, with an upstanding cylindrical side wall extending upwardly from the edge of the base wall to define a cylindrical catchment space. In what is envisaged to be a more commonly adopted form, S 10 the base wall may be square or rectangular, with four approximately square or Srectangular side walls extending upwardly from the edges of the base wall to define the catchment space.

One of the side walls, or a portion of one of the side walls, may be shorter than the remaining side walls and include an outwardly extending angled edge portion extending outwardly from the top edge of that wall for locating on or proximate to the lower edge of the pit opening. This potentially provides a substantially continuous flow path for storm water flowing through the pit entrance, over the angled edge portion, through the bag opening and into the catchment space of the bag.

The support surface may adopt any suitable form. In one form the support surface is configured for supporting the base wall of the filter bag thereon. The support surface may be a solid surface. More preferably, however, the support surface includes one or more apertures to permit the flow of storm water there through. The apertures may be of any suitable form and may include a plurality of perforations. Preferably, the perforations are of a size sufficient to permit the flow of storm water there through during typical operating conditions but small enough such that the surface rather than the filter bag substantially supports the weight of the water, litter and solid waste that may be present in the bag during typical operating conditions.

The filter bag support may include a support lip, and an upstanding side support extending between the support lip and the support surface, the support surface W \DELILA\DDM1COMPLETEMA FILTER DEVICEdoc

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being disposed below the lip. The support lip, side support and support surface 0 may be configured to define a filter bag receiving space for receiving the filter

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e bag therein.

00 0 5 The side support may adopt any suitable form. For example, the side support may include one or more support side walls extending upwardly from the support surface to the support lip. The support side walls may be solid. More preferably, however, the support side walls contain apertures (such as perforations), to enable the flow of storm water there through. In another form, S 10 the side support includes a plurality of connecting arms extending between and Sinterconnecting the support surface and support lip.

In one preferred form, the support is sized and shaped to fit within the pit in a manner so as to leave an overflow gap between the pit side walls and the side support and support lip. The overflow gap is provided in the event that the maximum storm water flow rate of the filter device is exceeded, in which case the storm water overflowing from the bag flows through the gap between the pit side walls and the side support and though the pit.

In a preferred form, the bag support includes at least one bag securing point for securing the bag to the support. It is envisaged that each of the securing points would be provided on the lip of the support, but may equally be provided at other suitable locations. Preferably, the bag is removable from the support to enable periodic emptying of the bag contents. It is to be appreciated, however, that the bag need not necessarily be removed in order to be emptied.

The support may be mounted permanently in position within a pit and the bag may be removably fitted to/within the support. The bag may be periodically removed from the support for emptying of the litter and solid waste therein collected. Once emptied, the bag could then be refitted to/within the support. In the event that the bag has been torn, cut or otherwise damaged then it may simply be replaced with a new bag.

W:\DELILAH\DDM\COMPLETEA FILTER DEVICEdoc The present invention is also directed to a filter bag for use in a filter device.

SThus, according to another broad aspect of the present invention, there is Sprovided a filter bag for use in a filter device for removing litter and solid waste from storm water entering a storm water drain. The filter device is adapted for location within a pit at an inlet to a storm water drain. The filter bag includes a wall structure defining a catchment space for collecting and retaining litter and solid waste from the storm water as it enters the drain. The filter bag includes San opening for the passage of storm water into the catchment space. The wall structure of the filter bag is porous, the porous wall structure permitting the flow S 10 of storm water there through, but substantially preventing the flow of solid litter 0 and waste of a specified size there through. The filter bag is adapted for support on a filter bag support for supporting the filter bag within the pit.

It will be convenient to hereinafter describe a preferred embodiment of the invention with reference to the accompanying figures. The particularity of the figures is to be understood as not limiting the preceding broad description of the invention.

Figure 1 is a front view of a filter device according to one embodiment of the present invention.

Figure 2 is a rear view of the filter device of Figure 1.

Figure 3 is a side view of the filter device of Figure 1.

Figure 4 is a front view of the filter bag support of the filter device Figure 1.

Figure 5 is a rear view of the filter bag support Figure 4.

Figure 6 is a side view of the filter bag support of Figure Referring to the Figures, there is illustrated a filter device 10 for removing litter and solid waste from storm water entering a storm water drain. The filter device is adapted for location within a pit (not illustrated) at an inlet to a storm water drain. The filter device 10 includes a filter bag 12. The filter bag 12 includes a wall structure 14 defining a catchment space 16 for collecting and retaining litter and solid waste from the storm water as it enters the drain.

W:\DELILAH\DDM\COMPLETE\A FILTER DEVICE doc The illustrated bag 12 is manufactured from bidim® A24 geotextile sold by 0 Geofabrics Australasia Pty Ltd. This material has a pore size of approximately

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S100pm, which enables the bag 12 to desirably collect at least a portion of the C. silt, sand and other particulate matter that may be present in the storm water entering the pit, thereby preventing such matter from entering, collecting and potentially blocking the storm water drain. It also prevents at least a portion of the silt, sand and other particulate matter present in the storm water fouling or otherwise damaging the environment at the drain exit. It is to be appreciated that other suitable fabrics or materials may be used for the manufacture of the bag 12, ifdesired.

The filter bag 12 includes an opening 18 for the passage of storm water into the catchment space 16. The wall structure 14 of the filter bag is porous, such that it permits the flow of storm water through the opening 18 and into the catchment space 16 and through the wall structure 14, but substantially prevents the flow of solid litter, waste and silt, sand and other particulate matter of a specified size through the wall structure 14. Thus, solid litter, waste, silt and other particulate matter is captured in the bag 12 for later removal. It is to be appreciated that not all silt, sand and other particulate matter would be captured within the bag 12.

Some silt, sand and other particulate matter may be of a sufficiently small grain size to pass through the wall structure 14.

The filter device 10 further includes a filter bag support 20 for supporting the filter bag 12 within the pit. The support 20 includes a support surface 22 for supporting the filter bag 12 thereon and at least one mount (not illustrated) for mounting the support 20 in position within the pit. The support may be manufactured from any suitable material including stainless steel, aluminium alloy, high density plastic or fiberglass.

It is to be appreciated that the bag 12 and support 20 are configured such that bag 12 is sized and shaped to fit within the support W:%DELILAH\DDM\COMPLETE\A FILTER DEVICE.doc The wall structure 14 may adopt any suitable size and shape, with the size and Sshape being, at least in part, dependent upon the size and shape of the pit into e which the filter device is to be fitted.

a, The bag 12 includes a rectangular base wall 24 (or simply 'base') and four side walls 26,28,30,32 extending upwardly from the base wall 24 to define the catchment space 16. The upper edges of the side walls 26,28,30,32 define the bag opening 18.

S 10 The side wall 26 is shorter than the remaining side walls 28,30,32 and includes San outwardly extending angled edge portion 34 extending outwardly from the top edge 36 of the wall 26 for locating on or proximate to the lower edge of the pit opening. This potentially provides a substantially continuous flow path for storm water flowing through the pit entrance, over the angled edge portion 34, through the bag opening 18 and into the catchment space 16 of the bag 12.

The support surface 22 is configured for supporting the base wall 24 of the filter bag 12 thereon. The support surface 22 includes a plurality of apertures in the form of perforations 38 (only some of which have been specifically identified) to permit the flow of storm water there through. The perforations 38 are of a size sufficient to permit the flow of storm water there through during typical operating conditions but small enough such that the surface 20 rather than the filter bag 12 substantially supports the weight of the water, litter and solid waste that may be present in the bag 12 during typical operating conditions.

The filter bag support 20 includes a support lip 40, and an upstanding side support 42 extending between the support lip 40 and the support surface 22, the support surface 22 being disposed below the lip 40. The support lip 40, side support 42 and support surface 22 is configured to define a filter bag receiving space 44 (see Figures 4 to 6) for receiving the filter bag 12 therein.

The side support 42 may adopt any suitable form, and in the illustrated embodiment includes a plurality of connecting arms 46 extending between, welded to and interconnecting the support surface 22 and support lip 40. The W.\DELILAHDD\COMPLETE\A FILTER DEVICE~doc provision of connecting arms 46 (only some of which have been labeled) Sprovides a series of apertures 48 in the side support 42 to enable to flow of e storm water there through.

oO 5 Although, not illustrated, the side support 42 may include one or more generally horizontally extending ribs welded to and interconnecting the arms 46 to provide added support to the bag 12. In the case of a plurality of ribs, the ribs may be approximately equidistantly spaced between the support lip 40 and the support surface 22. In the case of one rib, it may be located approximately midway S 10 between the support lip 40 and the support surface 22.

The support 42 is sized and shaped to fit within the pit in a manner so as to leave an overflow gap between the pit side walls, and the side support 42 and support lip 40. The overflow gap is provided in the event that the maximum storm water flow rate of the filter device 10 is exceeded, in which case the storm water overflowing from the bag 12 flows through the gap between the pit side walls and the side support 42 and though the pit.

The upper edge 50 of each of the side walls 26,28,30,32 includes a longitudinally extending closed loop 52 for receiving a draw cord 54 (see Figure 6) there through. The draw cord 52 is exposed at bag corners 56,58,60,62 for tying to, or otherwise securing to the attachment points 64,66,68,70 integrally formed on the support lip 40 of the support 20. The attachment points 64,66,68,70 may extend inwardly or outwardly of the support 20. This securing arrangement allows for the simple removal of the bag 12 from the support 20 for periodic emptying or, if necessary, replacement. The closed loops 52 are produced by stitching or sewing the upper edges 50 of the sidewalls 28,30,32, but could instead be produced by, for example, fusing or molding the upper edges 50. Likewise, the side walls 26,26,30,32 are stitched together along their respective edges, but may instead be fused or molded together.

It is to be appreciated that the upper edge 50 is, in use, fitted over the support lip W.\DELILAIIDDM\COMPLETE\A FILTER DEVICEdoc The support 20 would be configured for permanently, but removably mounting Sin position within a pit by suitable mounting means (not illustrated).

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Finally, it is to be understood that various alterations, modifications and/or 0 5 additions may be introduced into the construction and arrangement of the parts previously described without departing from the spirit or ambit of this invention.

c Without limiting the claim scope that may be sought in any Australian or Soverseas patent application claiming priority from the present application, the 10 following claims are provided.

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Claims

2. A filter device according to claim 1, wherein the wall structure is manufactured at least substantially from at least one of fabric and synthetic material.
3. A filter device according to claim 2, wherein the wall structure is manufactured at least substantially from synthetic material.
4. A filter device according to claim 3, wherein the synthetic material is non- woven. A filter device according to claim 3 or 4, wherein the material includes a pore size in the range of approximately 90pm to 120pm. W \DELILAH\DDM\COMPLETE\A FILTER DEVICEdoc
6. A filter device according to claim 5, wherein the material includes a pore Ssize in the range of approximately 100pm to 1101pm.
7. A filter device according to any one of the preceding claims, wherein the 0 5 wall structure includes at least one bag wall. (N
8. A filter device according to claim 7, wherein the bag includes a base wall and at least one side wall extending upwardly from the base wall to define the catchment space.
9. A filter device according to claim 8, wherein the bag includes a base wall and four side walls extending upwardly from the base wall to define the catchment space.
10. A filter device according to any one of the preceding claims, wherein the supporting surface includes a support base.
11. A filter device according to claim 10, wherein the support base includes a plurality of apertures to permit the flow of storm water there through.
12. A filter device according to claim 11, wherein the plurality of apertures are in the form of a plurality of perforations.
13. A filter device according to any one of the preceding claims, wherein the filter bag support includes a support lip, and an upstanding side support extending between the support lip and the support base, the support base being disposed below the lip; the support lip, the side support and support base defining a filter bag receiving space.
14. A filter device according to claim 13, wherein the side support includes a plurality of connecting arms connecting the support lip to the support base. A filter device according to any one of the preceding claims, wherein the support includes at least one bag securing point. W:.\DELILAII\DDM\COMPLETE\A FILTER DEVICE doc 0 16. A filter bag according to claim 15 when dependent on claim 13 or 14, (N Swherein each of the securing points is provided on the support lip. a) 00 5 17. A filter bag according to any one of the preceding claims, wherein the filter bag is configured to capture at least some silt, sand or other particulate matter entering the pit (-i N 18. A filter bag for use in a filter device for removing litter and solid waste from storm water entering a storm water drain, the filter device being adapted 0 for location within a pit at an inlet to a storm water drain, the filter bag including a wall structure defining a catchment space for collecting and retaining litter and solid waste from the storm water as it enters the drain, the filter bag including an opening for the passage of storm water into the catchment space, the wall structure of the filter bag being porous, the porous wall structure permitting the flow of storm water there through, but substantially preventing the flow of solid litter and waste of a specified size there through, the filter bag adapted for support on a filter bag support for supporting the filter bag within the pit.
19. A filter device substantially as herein described and illustrated. A filter bag for use in a filter device substantially as herein described and illustrated. W:\DELILAH\DDM\COMPLETE\A FILTER DEVICE doc