AU4517100A

AU4517100A - Stormwater catchpit filter

Info

Publication number: AU4517100A
Application number: AU45171/00A
Authority: AU
Inventors: Michael Morton Hannah; Paul Gregory Yeoman
Original assignee: ENVIROPOD HOLDINGS Ltd
Current assignee: EHL Ltd
Priority date: 1999-07-12
Filing date: 2000-07-12
Publication date: 2001-01-18
Anticipated expiration: 2020-07-12
Also published as: AU780521B2; NZ336761A

Description

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Page(s).,. were not lodged with this application Background This invention relates to an apparatus and method for improving pollution control in stormwater drains and in particular, catchpits.

The applicant is the owner of New Zealand Patent 299114 entitled "A filter device" and the contents of that specification are included herein by reference.

It has been found that there is a need for a filter unit which can be maintained by the owner and reused on other sites and which can become a standard design for retrofitting into existing catchpits.

It is an object of the present invention to provide a filter unit which can be used to filter stormwater run off from construction sites, earthwork sites, subdivisions and from general paved areas.

It is a further object of the present invention to provide a single filter unit adapted to fit new or existing stormwater catchpits, gully pits, cesspits and catchbasins and the like (hereafter referred to oo. as catchpits) of varying sizes which can be relocated on other sites as and when required.

To achieve these objects the filter unit of the present invention can be adjusted both vertically and horizontally to fit different size catchpits.

In one broad aspect of the present invention there is provided a filter unit adapted to remove suspended solids and water borne litter from stormwater, said filter unit comprising a cage means, 25 cooperating legs which are extendible below said cage and securable therewith, said legs being adapted to act as a load bearing support for the filter unit, flexible flaps removably attached to the upper section of the cage which are adapted to pivot and which form a seal to the surrounding stormwater catchpit.

Preferably the cage is equipped with lifting handles located on two sides of the cage and below the flexible flaps, which also act as spacers.

The present invention will be more fully described by reference to a preferred embodiment, given F863fps.699 -2 by way of example only, as illustrated in the attached drawings in which; Figure 1 is a perspective view of the filter unit of the present invention.

Figure 2 is a cross-section view along the lines A-A of Fig. 3 showing the filter unit of Figure 1 insitu in a stormwater catchment pit.

Figure 3 is a plan view of the filter unit of the present invention insitu in a stormwater catchment pit.

Figure 4 is a section view along the lines BB of Figure 3.

In Figure 1 there is shown the filter unit 1 which comprises a steel cage 2, extendible lockable legs 3 joined at their lower ends to a rectangular frame 4. The legs are extendible from the base of cage 2 and lockable therewith by known locking means 7 by being set at an angle to the cage wall rather than projecting normal thereto. Preferably the locking means 7 has extending handles 8 which almost abut with the side walls of the stormwater catchment pit and act as spacers from two pit S' walls. Also shown in Figure 1 are lifting handles 9 on either side of the cage 2. Flexible flaps surround the top four sides of cage 2 and are hinged to overflow panels 11 (with drip deflectors 0 11 la) thereon. The hinged flaps project sideways from the cage 2 to abut with and seal to the o:1. surrounding stormwater catchment pit to catch all run-off water. The overflow panels 11 have removable overflow cut-off sections .12 which slide in and out. The hinged flaps provide for horizontal adjustment as they can be raised to differing heights to accommodate differing widths of catchpits.

As shown in Figure 1 one side of the cage 2 opens to allow easy input and removal of for a filter bag 15 (shown frosted). The opening panel of the cage 2 hinges about the base of cage 2 and is secured shut by locking pins 13 on the cage which cooperate with locking pins 13a.

In Figure 2 there is shown a catchment pit 20 having pit walls 21 and 22. The cage 2 is seen supported on the extendible legs 3 which surmount the base frame 4. The extending handles 8 and lifting handles 9 act as spacers to maintain the cage 2 from abutting the pit walls 21 or 22 F863fps.699 during heavy stormwater run-off. The hinged flexible flaps 10 are seen at the top of cage 2 abutting the pit wall 21, 22 to form a seal therearound. When the pit is narrow, as shown with dashed lines, the hinged flexible flaps 10a are in a more vertical position than flaps 10, when forming a seal around the inside of the catchment pit 21 a.

Shown in ghosting is a filter bag 15 having a standard ring support 16 located within the cage 2.

The handles 9 on the cage 2 can be seen almost abutting the pit wall. These handles act not only as lifting handles to remove the filter unit from the catchment pit but to provide additional horizontal support along with the locking handles 8.

In Figure 3 the cage 2 is seen located within a catchpit In Figure 4 can be seen the geotextile filter bag 15 partly removed from the cage 2 when the side of the cage is in an open position as shown.

In use the filter unit of the present invention is placed within a stormwater catchment pit and the

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legs are adjusted for variance in pit depth. The threaded locking handles are adjusted to lock the .20 legs in place and to act as spacers between the cage and the pit walls, to allow for flow around the filter unit.

The flexible rubber flaps are designed to seal against the pit walls when the filter unit is placed inside the pit acting as a funnel to direct run-off into the filter bag. When the pit size is small the rubber flaps will be in a more vertical position and provide a seal around the inside of the catchment pit.

**9 A geotextile filter bag is placed within the cage and can be removed by opening the side panel of the cage and sliding the bag from support means.

Self maintenance is achieved by folding the rubber flaps inward to allow access to the lifting handles, then lifting the filter unit either manually or by hydraulic means such as a forklift or loader, from the pit. The side panel of the cage is then opened and the filter bag slid out. A new F863fps.699 -4 filter bag is then placed in the frame and the filter unit placed back into the pit. The rubber flaps are then folded outwardly to form a seal around the walls of the pit.

As the filter unit of the present invention is able to be adjusted both vertically and horizontally, the filter unit is reusable on other sites. For example a filter unit may be used on a construction site with a geotextile liner to filter silt or sediment from site run-off and, then removed and reused in an existing carpark with a 1000 micron trash collector bag to remove water borne litter.

Whilst the present invention has been described by way of example and with reference to the preferred embodiment, it is to be understood that modifications and variations have been made thereto without departing from the scope or spirit of the invention, for example the filter bag can be made of any suitable material.

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Claims

1. A filter unit adapted to remove suspended solids and water borne litter from stormwater, said filter unit comprising a cage means, cooperating legs which are extendible below said cage and securable therewith, said legs being adapted to act as a load bearing support for the filter unit, flexible flaps removably attached to the upper section of the cage which are adapted to pivot and which form a seal to the surrounding stonnwater catchpit.

2. A filter unit as claimed in Claim 1 wherein the cage has lifting means located' on two sides of the cage.

3. A filter unit as claimed in Claim 2 wherein the lifting means comprise slots adapted to allow manual or mechanical removal of the cage from the catchpit.

4. A filter unit as claimed in Claim 2 wherein the lifting means comprise oo handles located on two sides of the cage and below the flexible flaps.

5. A filter unit as claimed in claim 4 wherein the lifting handles also act as spacers adapted to maintain the filter unit away from the sides of the catchpit.

6. A filter unit as claimed in any one of the preceding claims wherein one side of the cage can be opened to ease the removal of the filter bag.

7. A filter unit substantially as herein described with reference to the attached drawings.