AU759950B2 - A filter assembly - Google Patents

Description

S&F Ref: 510492

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

*9 9r a *999 9 9 Name and Address of Applicant Actual Inventor(s): Address for Service: Invention Title: Sediment Filtration Systems 79 Union Street North Sydney NSW 2060 Australia Christopher J. Rochfort and Eric J. Love Spruson Ferguson St Martins Tower 31 Market Street Sydney NSW 2000 A Filter Assembly ASSOCIATED PROVISIONAL APPLICATION DETAILS [33] Country [31] Applic. No(s) AU PQ0660 [32] Application Date 31 May 1999 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815c A FILTER ASSEMBLY Field of the Invention The present invention relates to filtration devices. More particularly, though not exclusively, the invention relates to a filter assembly for reducing silt and sediment from entering stormwater systems and waterways.

Background of the Invention It is quite common after heavy rainfall that the resultant water run-off from sites such as roadways, agricultural sites, mining and construction sites, causes substantial movement of silt and sediment towards stormwater systems and waterways. The release S0 (or migration) of large quantities of silt and sediment not only results in erosion and land degradation, but causes a buildup of silt and sediment blocking stormwater systems and clogging waterways. This in turn directly affects the entire ecosystem of a waterway and its surrounding environment.

In an attempt to alleviate this problem some government authorities have constructed, at great expense, filtration systems around their stormwater systems and waterways in an attempt to reduce the buildup of silt and sediment.

One common method is to use hay bails in front of and around entrances to stormwater systems. These hay bails act as a filter, catching silt and sediment before it enters the stormwater system. Hay bails, however, are expensive and over time degrade and break down.

Accordingly, it would be desirable to have an inexpensive, man made, reusable "hay bail" which reliably reduces silt and sediment from entering stormwater systems and waterways.

Object of the Invention It is an object of the present invention to overcome or ameliorate some of the disadvantages of the prior art, or at least to provide a useful alternative.

Disclosure of the Invention There is disclosed herein a multidirectional filter assembly having, [R:\LIBLL0778') doc:KlfI 24J.EB 2003 14:41 SPRUSON FERGUSON NO. 7540 P. 2 -2a frame cover substantially surrounding said frame, at least one filter cartridge being receivable within one of said chambers, a cartridge cover substantially surrounding said at least one cartridge, and wherein said covers in use permit fluid to pass therethrough.

Preferably, one or more additional filter cartridges are located with said chambers.

Preferably, said covers and/or said cartridges are replaceable and/or removable.

Preferably, said frame is formed of mesh.

Preferably, said covers are formed from a polypropylene geotextile.

Preferably, said frame is in the form of a rigid permeable plastic box.

Brief Description of the Drawings A preferred form of the present invention will now be described by way of example only with reference to the accompanying drawings, wherein: Figure 1A is a photographic representation of a filter assembly according to the IS invention; Figure 1B is a schematic cutaway plan view of the filter assembly as shown in Figure 1A; Figure 2 is a photographic representation of a frame according to the invention; Figure 3 is a photographic representation of filter cartridges according to the invention;

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Figure 4 is a photographic representation of a frame cover according to the invention; and Figure 5 is a photographic representation of a filter cartridge in the form of a flexible sock.

Detailed Description of the Drawings In Figures IA and IB of the accompanying drawings there is depicted a filter assembly I which substantially reduces silt and sediment from entering stormwater systems and waterways as a result of rainfall events and other water runoff.

These filter assemblies I are strategically placed on the ground in various orientations (for example, length ways or width ways) in critical areas to intercept and capture water runoff containing silt, sediment and other contaminants such as, chemical, physical and/or biological.

As best shown in Figure 1B, the preferred embodiment of the invention provides a multidirectional filter assembly 1 having: a frame 2 defining a plurality of chambers 3. A cover 4 substantially surrounds the frame 2 (as best shown in Figure 1A). At least one filter cartridge 5, substantially surrounded by a cartridge cover 6 (as best shown in Figure is receivable within one of the chambers 3.

The assembly 1 is in effect a five stage filtration device.

In contaminant filtration stage 1, the filter assembly 1 acts as a barrier by slowing the velocity of a water flow sufficiently to allow some suspended contaminants to settle.

At stage 2, contaminant filtration occurs whereby some of the water passes into the filter assembly 1 through the frame cover 4 and frame 2.

In stage 3, water passes through the filter cartridge cover 6 and into filter cartridge At stage 4, water passes through the filter cartridge medium mixture located within the filter cartridge 5 where it is cleansed and through the filter cover 6 on the other side.

IR \-IRLL ]07789.doc:KIll The fifth and final stage occurs when water passes out through frame 2 and the frame cover 4 on the other side and into the stormwater system.

Due to the nature of the filter medium the filter assembly I at least in a preferred form reduces other contaminants found in stormwater such as toxic chemicals, heavy Smetals, nutrients and biological and chemical oxygen demand from entering natural waterways.

Figure 2 shows a photographic top view of the frame 2 of the filter assembly 1.

The frame 2 is preferably constructed from using a rigid permeable plastic box that is :assembled in a rectangular bail frame configuration with two internal support pieces o inserted in an offset formation. The offset allows for the placement of one or .more replaceable polypropylene geotextile filter cartridges 5 (not shown) in chambers 3.

~As depicted in Figure 3, the filter cartridges 5 provide enhanced filtration by use of a new unique filter medium mixture containing recycled organic material, zeolite, gypsum and naturally occurring and/or biologically engineering microorganisms 15 contained in a geotextile bag.

In a preferred form, the filter cartridges 5 are approximately 400 mm x 440 mm by 100 mm and contain preferably 10 litres of filter medium when filled. Depending upon the application and siting of the filter assembly 1 other sizes may also be utilised.

Once the polypropylene geotextile filter cartridges 5 are placed inside the frame 2, the entire assembly is inserted inside a polypropylene geotextile cover 4. In a preferred form (not shown) a top lid of the frame 2 is provided and is fitted with an extended flap of the cover 4 being folded in and over locking clips prior to the frame lid being fitted. The top flap and front flap of the cover 4 are positioned so that the top flap and front flap are held in place when connecting the top frame lid.

The frame 2 in a preferred form is approximately 460 mm x 485 mm by 605 mm.

The dimensions may vary because the cover 4 is loosely fitted to allow some free play when installing. The loose fitting will also allow additional filter cartridges 5 to be placed inside the cover 4 but outside the frame 2 to allow nesting into irregular shaped ground areas and gutters.

IR:\l.IILL.07789.doc:KEIH The filter cartridges 5 and geotextile covers 4, 6 should preferably be replaced regularly. For example, every 6 months or after a predetermined number of rainfall events. This may also vary depending upon thle site and/or the extent of runoff contaminants.

In one preferred form, (not shown) the invention canl form a single use filter assembly. This single use assembly is based onl the above mentioned filter assembly 1 but does not utilise the framne 2 or filter cartridges 5. Tis assembly is designed to simply provide a barrier. It consists of a cover that is filled with a unique combination of recycled organic material, zeolite and gypsum and, naturally occurring and/or biologically *:10 engineering microorganisms to form a substantially box shape. The cover has securing lugs to allow the use of a stake or other fixing device to be inserted to hold the assembly in place onl the ground. This single use assembly is approximately 600 mml by 370 mml by 320 mm. The inside of the single use assembly contains a floating aeration cavity to assist decontami nation also making thle structure lighter and more manageable. This ii assembly acts as a barrier to slow the velocity of contamninated runoff for sufficient time to allow a contaminated sediment to settle. It canl also be used to direct water. The amount of toxic chemicals contained in the sediment and solution is reduced by bioremnediation when absorbed into the barrier bail. Slowing the velocity of stormwater runoff also reduces further erosion and sediment migration.

toFigure 6, there is shown a itrcartridge 10in thle form- 01 an elongate flexible sock approximately 1135 mml long by 160 mml wide by 30 mil thick.

Tis cartridge 1 0 preferably contains 15 litres of organic material, zeolite and gypsum, and naturally occurring and/or biologically engineered microorganisms. This cartridge directs water, towards thle filter assembly 1. It canl also filter contaminated water.

Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

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Claims (1)

1. 24.,FEB. 2003 14:42 SPRUSON FERGUSON NO. 7540 P. 3 -6- The claims defining the invention are as follows:- I. A multidirectional filter assembly having, a frame defining a plurality of chambers, a frame cover substantially surrounding said frame, at least one filter cartridge being receivable within one of said chambers, a cartridge cover substantially surrounding said at least one cartridge, and wherein said covers in use permit fluid to pass therethrough. 2. The assembly of claim 1, wherein one or more additional filter cartridges are located within said chambers. 3. The assembly of claim 1 or claim 2, wherein one or more additional filter cartridges are located inside the frame cover but outside the frame. 4. The assembly of any one of the preceding claims, wherein said covers and/or said cartridges are replaceable and/or removable. The assembly of any one of the preceding claims, wherein said frame is formed of mesh. 6. The assembly of any one of the preceding claims, wherein said covers are formed from a polypropylene geotextile. 7. The assembly of any one of claims 1 to 4, wherein said frame is in the form of a rigid permeable plastic box. 8. A multidirectional filter assembly, substantially as herein described with reference to any one of the embodiments of the invention shown in the accompanying drawings. Dated 17 February, 2003 Sediment Filtration Systems Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON LU 'q LIBLL1077a9.doc KEN