AU785447B2

AU785447B2 - Gross pollutant trap

Info

Publication number: AU785447B2
Application number: AU44433/02A
Authority: AU
Inventors: Alberto Ferraro; Peter Hodson; Michael Mucciacciaro
Original assignee: GEORGIOU GROUP Pty Ltd
Current assignee: GEORGIOU GROUP Pty Ltd
Priority date: 2001-05-29
Filing date: 2002-05-29
Publication date: 2007-06-28
Anticipated expiration: 2022-05-29
Also published as: AU4443302A

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Name of Applicant: Actual Inventors Address for service is: Georgiou Group Pty Ltd Peter HODSON, Alberto FERRARO Michael

MUCCIACCIARO

WRAY ASSOCIATES 239 Adelaide Terrace Perth, WA 6000 Attorney code: WR Invention Title: "Gross Pollutant Trap" Details of Associated Provisional Application No: PR5332 The following statement is a full description of this invention, including the best method of performing it known to me:- -2- "Gross Pollutant Trap" Field of the Invention The present invention relates to a gross pollutant trap. More particularly, the gross pollutant trap of the present invention is intended for use in extracting gross pollutants such as sand, floatables and hydrocarbons from stormwater.

Background Art A variety of designs are presently utilised as gross pollutant traps in stormwater and commercial applications. These designs typically employ a cyclonic action in combination with a provision for settling to separate floatables and particulate, such as sand and silt, matter from the stormwater.

The presently utilised designs for gross pollutant traps are typically difficult to clean as a result of their complicated construction. Further, known gross pollutant traps do not typically prevent through flow of hydrocarbons without the need for additional chambers and/or apparatus for their retention.

One known construction of trap uses three separate chambers and required both an inlet drop pipe and decant pipe for adequate operation. Further, additional construction is required to adequately retain hydrocarbons.

The gross pollutant trap of the present invention has as one object thereof to overcome substantially, or at least provide a useful alternative to, the abovementioned problems associated with the prior art.

The preceding discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge in Australia as at the priority date of the application.

-3- Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Disclosure of the Invention In accordance with the present invention there is provided a gross pollutant trap comprising a treatment chamber, an inlet and an outlet, the treatment chamber having provided therein a baffle member extending from the bottom of the treatment chamber to a position spaced from an upper end of the treatment chamber, the baffle member thereby dividing the treatment chamber into an inlet portion and an outlet portion, wherein the baffle member includes a lower fluid permeable portion and an upper impermeable portion extending above the lower fluid permeable portion to occlude a direct path at least between said inlet and said outlet.

Preferably, the inlet opens into the inlet portion below the uppermost level of the impermeable portion of the baffle member within the treatment chamber. Further, the outlet preferably opens into the outlet portion below the uppermost level of the impermeable portion of the baffle member within the treatment chamber. By the term "below", it is intended that the uppermost extent of the inlet portion or outlet portion can be at the same height as the uppermost level of the impermeable portion.

Preferably the outlet portion has provided therein a floating material barrier proximal to said outlet whereby oils and other hydrocarbons in the water being treated are not readily passed into the outlet as the water level within the treatment chamber rises.

In one preferred form of the invention, the floating material barrier is provided in the form of a depending portion formed integrally with the outlet.

Preferably the baffle member extends entirely across the treatment chamber.

-4- Preferably the fluid permeable portion comprises a mesh portion.

Preferably the impermeable portion comprises a plate member.

Preferably said impermeable portion extends entirely across the treatment chamber.

In one preferred form of the invention, the baffle member further includes an upper mesh portion extending above the impermeable plate portion. The upper mesh portion allows excess liquid to spill through in the event of surging, helping to avoid solid material spilling over into the outlet portion.

Preferably the upper end of the treatment chamber is open.

Still preferably the upper end of the treatment chamber has a lid, adapted to prevent access during normal use and allow access for cleaning of the treatment chamber.

In use, the gross pollutant trap may be buried up to the height of the lid, such that the lid permits access to the chamber.

In one preferred form of the invention, the treatment chamber comprises a plurality of circular portions, adapted to be axially fitted together during installation to form the treatment chamber.

In an alternate preferred form of the invention, there is provided an upper chamber extending above the upper end of the treatment chamber adapted to allow access to the treatment chamber wherein the upper chamber. The upper chamber may preferably be provided with a lid at its uppermost portion.

In use, the gross pollutant trap may be buried such that only the uppermost portion of the upper chamber is visible from the surface.

In one preferred form of the invention, the treatment chamber is provided with a base closure at the bottom thereof, whereby the base closure includes a drain aperture extending therefrom to an area outside and below the gross pollutant trap. Preferably, in use the drain aperture may be substantially filled with aggregate. The drain aperture allows excess fluid to drain from the treatment chamber, helping to avoid overflow of the treatment chamber.

In an alternate preferred form of the invention, in use, the bottom of the treatment chamber comprises aggregate and is adapted to act as a drain.

In one preferred form of the invention, the upper mesh portion of the baffle member extends to the upper end of the treatment chamber.

Brief Description of the Drawings The gross pollutant trap of the present invention will now be described by way of example only, with reference to three embodiments thereof illustrated in the accompanying drawings, in which: Figure 1 is a side view of a gross pollutant trap in accordance with a first embodiment of the present invention; Figure 2 is top plan view of a gross pollutant trap in accordance with Figure 1; Figure 3 is a cross sectional side view of the gross pollutant trap of Figure 1; Figure 4 is a cross-sectional side view of a gross pollutant trap in accordance with a second embodiment of the present invention; Figure 5 is a second cross-sectional side view of the gross pollutant trap of Figure 4; and Figure 6 is a cross-sectional side view of a gross pollutant trap in accordance with a third embodiment of the present invention.

Best Mode(s) for Carrying Out the Invention In Figures 1 to 3 there is shown a gross pollutant trap 10 comprising a substantially cylindrical treatment chamber 12 divided into an inlet portion 14 and an outlet portion 16 by a generally planar baffle member 18.

The treatment chamber 12 has an open upper end 20 and a closed base 22. The base 22 has a drain aperture 24 provided therein, extending between the treatment chamber 16 and an area outside and below the gross pollutant trap The drain aperture 24 is filled with aggregate (not shown) in use.

The baffle 18 extends upwardly from the base 22 to a position spaced away from the upper end 20 of the treatment chamber 12.

The inlet portion 14 is provided with an inlet pipe 26 to direct incoming stormwater into the inlet portion 14. The inlet pipe 26 connects to the treatment chamber 12 at a level just below the upper limit of the baffle 18. An outlet pipe 28 is arranged so as to extract water from the outlet portion 16 of the treatment chamber 12 and pass such to a point remote the gross pollutant trap 10. The outlet pipe 28 is provided with an elbow 30 creating a short depending portion 32 of the outlet 28 the depending portion 32 extends downwardly from the elbow 30 to a point below that of the inlet pipe 26 and also the remainder of the outlet pipe 28.

The baffle member 18 extends across the treatment chamber 12, as best seen in Figure 2. The baffle member 18 comprises an upper impermeable plate portion 34 and a lower mesh portion 36. Both the baffle plate portion 34 and the mesh portion 36 extend across the full width of the baffle 18.

It is envisaged that a lid (not shown) will be used for the treatment chamber 12 when in use, the lid both preventing access during normal use but allowing access for cleaning.

In use, stormwater is directed to the gross pollutant trap 10 through the inlet pipe 26 and passes into the inlet portion 14 of the treatment chamber 12. The -7incoming stormwater with any entrained solids and floatables may hit the plate portion 34 and be retained, at least momentarily in the treatment chamber inlet portion 14. This retention of the incoming stormwater in the treatment chamber inlet portion 14 provides some time for settling of sand and sediment. The floatables are retained within the treatment chamber inlet portion 14 and only the water, together with some smaller solids such as sand and sediment, will pass through the mesh portion 36 of the baffle 18 into the treatment chamber outlet portion 16. If the plate portion 34 were not provided and the baffle member 18 was all mesh, fine particulates could pass straight to the outlet 28 As the water level within the treatment chamber 12 rises due to the inflow of stormwater into the gross pollutant trap 10 the level within the treatment chamber outlet portion 16 will rise. Any oils or hydrocarbons are typically suspended at or very near the surface of the water in the treatment chamber outlet portion 16.

There is minimal re-suspension of settled solids in the treatment chamber outlet portion 16 due to the action of the baffle member 18 protecting settled solids such as sand and silt from any disruption by incoming stormwater.

The provision of the depending portion 32 of the outlet pipe 28 ensures that minimal hydrocarbons and oils are passed through the outlet pipe 28 as the water level in the treatment chamber outlet portion 16 rises. During times of particularly high flow into the gross pollutant trap 10 water can bypass the baffle member 18 by flowing over its upper end. Even in such a "by-pass" situation, the arrangement of the outlet pipe 28 and depending portion 32 thereof should ensure that minimal entrained solids are allowed to exit the gross pollutant trap In Figures 4 and 5 there is shown a gross pollutant trap 50 in accordance with a second embodiment of the present invention. The gross pollutant traps 10 and are substantially similar in construction and like numerals denote like parts.

The gross pollutant trap 50 is shown to be constructed substantially of moulded concrete. For example, the treatment chamber 12 is composed of three circular portions 52, 54, and 56. The portions 52, 54 and 56 are fitted together during installation to construct the treatment chamber 12 in combination with the -8moulded concrete base 22. The baffle member 18 is subsequently fitted into the treatment chamber 12 to define the treatment chamber portions 14 and 16. The treatment chamber 12 is subsequently provided with a lid 58.

In the gross pollutant trap 50 the baffle member 18 is located within the treatment chamber 12 such that the outlet chamber 16 is somewhat smaller than the inlet chamber 14, thereby providing greater capacity for settling of sediment and floatables within the inlet chamber 14.

It is envisaged that the plate portion 34 of the baffle member 18 may be formed of galvanised steel whilst the mesh portion 36 thereof may be formed of stainless steel mesh.

In Figure 6 there is shown a gross pollutant trap 60 in accordance with a third embodiment of the present invention. The gross pollutant traps 10, 50 and 60 are substantially similar in construction and like numerals denote like parts.

The gross pollutant trap 60 comprises a substantially cylindrical treatment chamber 12 divided into an inlet portion 14 and an outlet portion 16 by a generally planar baffle member 62.

The baffle member 62 extends across the width of the treatment chamber 12 and extends upwardly from the base 22 to a position spaced from the upper end 20 of the treatment chamber 12. The baffle member 62 comprises an upper mesh portion 64, a lower mesh portion 36 and a middle impermeable plate portion 34 located therebetween. The upper mesh portion 64, the lower mesh portion 36 and the middle plate portion 34 extend across the full width of the baffle 62. It is envisaged that the gauge of the upper mesh portion 64 is larger than the gauge of the lower mesh portion 36.

It is envisaged that the plate portion 34 of the baffle member 62 may be formed of galvanised steel whilst the upper mesh portion 64 and the lower mesh portion 36 thereof may be formed of stainless steel.

It is further envisaged that the mesh of the upper mesh portion 64 is 25 mm diameter and the mesh of the lower mesh portion 36 is 5 mm.

The gross pollutant trap 60 has an upper chamber 66 and an aperture 68 extending from the upper chamber 66 downwardly to the treatment chamber 12.

The upper chamber 66 comprises walls 70 and an upper end 72. The upper end 72 is provided with an aperture 74 adapted to permit access to the upper chamber 66. It is envisaged that a lid 76 will be used for the upper chamber 66 when in use.

In use, the gross pollutant trap 60 may be buried up to the level of the 76 of the upper chamber 66, thereby ensuring access to the treatment chamber is possible.

It is envisaged that the inlet pipe 26 may be arranged so as to be "off-centre" without substantially affecting the performance of the gross pollutant trap 10, and 60. It is possible that such an arrangement may be chosen due the orientation of the gross pollutant traps 10, 50 and 60 in use. Further, such an arrangement may be used to increase disruption in the in-flowing stormwater thereby affecting the settling characteristics within the treatment chamber portion 14.

It is envisaged that the gross pollutant traps 10, 50 and 60 may be provided with a diameter between 1200 mm and 3000 mm with a preferred diameter of 1500 mm and a preferred height of 2000 mm, although it is to be understood that other proportions may be adopted for specific applications without altering the scope of the present invention. For example, it is envisaged that a decreased diameter of the treatment chamber 12 should allow an increased depth, and vice versa.

It is further envisaged that the drain aperture 24 be provided as an optional feature, dependent upon individual application requirements.

As can be seen from the above description, the gross pollutant traps 10, 50 and of the present invention provide an efficient means of removing floatables and entrained solids from stormwater and other waste waters in a relatively simple manner and using a simple construction when compared with those of the prior art.

Modifications and variations such as would be apparent to the skilled addressee are considered to fall within the scope of the present invention.

Claims

1. A gross pollutant trap comprising a treatment chamber, an inlet and an outlet, the treatment chamber having provided therein a baffle member extending from the bottom of the treatment chamber to a position spaced from an upper end of the treatment chamber, the baffle member thereby dividing the treatment chamber into an inlet portion and an outlet portion, wherein the baffle member includes a lower fluid permeable portion and an upper impermeable portion extending above the lower fluid permeable portion to occlude a direct path at least between said inlet and said outlet.

2. A gross pollutant trap according to claim 1, wherein the inlet opens into the inlet portion below the uppermost level of the impermeable portion of the baffle member within the treatment chamber.

3. A gross pollutant trap according to claims 1 or 2, the outlet opens into the outlet chamber below the uppermost level of the impermeable portion of the baffle member within the treatment chamber.

4. A gross pollutant trap according any one of the preceding claims, wherein the outlet portion has provided a floating material barrier proximal to said outlet whereby oils and other hydrocarbons in the water being treated are not readily passed into the outlet as the water level within the treatment chamber rises.

5. A gross pollutant trap according to claim 4 wherein the floating material barrier is provided in the form of a depending portion formed integrally with the outlet.

6. A gross pollutant trap according any one of the preceding claims, wherein the baffle member extends entirely across the treatment chamber.

7. A gross pollutant trap according any one of the preceding claims, wherein the fluid permeable portion comprises a mesh portion. -12-

8. A gross pollutant trap according any one of the preceding claims, wherein the impermeable portion comprises a plate member.

9. A gross pollutant trap according any one of the preceding claims, wherein said impermeable portion extends entirely across the treatment chamber.

10.A gross pollutant trap according any one of the preceding claims, wherein the baffle member further includes an upper mesh portion extending above the impermeable plate portion.

11.A gross pollutant trap according any one of the preceding claims, wherein the upper end of the treatment chamber is open.

12.A gross pollutant trap according any one of the preceding claims, wherein the upper end of the treatment chamber has a lid, adapted to prevent access during normal use and allow access for cleaning of the treatment chamber.

13.A gross pollutant trap according any one of the preceding claims, wherein the treatment chamber comprises a plurality of circular portions, adapted to be axially fitted together during installation to form the treatment chamber.

14.A gross pollutant trap according any one of the preceding claims, wherein there is provided an upper chamber extending above the upper end of the treatment chamber adapted to allow access to the treatment chamber wherein the upper chamber.

15.A gross pollutant trap according to claim 14, wherein the upper chamber is provided with a lid at its uppermost portion.

16.A gross pollutant trap according any one of the preceding claims, wherein the treatment chamber is provided with a base closure at the bottom thereof.

17. A gross pollutant trap according claim 16, wherein the base closure includes a drain aperture extending therefrom to an area outside and below the gross pollutant trap. -13-

18.A gross pollutant trap according any of the preceding claims, wherein the upper mesh portion of the baffle member extends to the upper end of the treatment chamber.

19.A gross pollutant trap substantially as herein described, with reference to the drawings. Dated this Twenty Ninth day of May 2002. Georgiou Group Pty Ltd Applicant Wray Associates Perth, Western Australia Patent Attorneys for the Applicant(s)