WO2015170994A1

WO2015170994A1 - Improvements in and relating to the aeration of fluids

Info

Publication number: WO2015170994A1
Application number: PCT/NZ2015/000035
Authority: WO
Inventors: Bruce HENLEY
Original assignee: Henley Industries Limited
Priority date: 2014-05-07
Filing date: 2015-05-05
Publication date: 2015-11-12
Also published as: NZ624660A

Abstract

The present invention relates to a water aeration disc. The water aeration disc includes a hub portion providing a rotational axis through the center of the disc, a fluid engaging surface on each side of the disc, the fluid engaging surfaces of the disc including a plurality of fluid engaging structures. Each fluid engaging structure defines a raised surface on one side of the disc and a recessed surface on the opposite side of the disc. The recessed surface of a fluid engaging structure on one side of the disc is formed into a back of the raised surface on the opposite side of the disc. The raised fluid engaging structures include a front which, in use, leads into a fluid and is configured to substantially prevent splashing upon entry into the fluid.

Description

IMPROVEMENTS IN AND RELATING TO THE AERATION OF FLUIDS

TECHNICAL FIELD

The present invention relates to improvements in and relating to the aeration of fluids. The invention has particular application in the field of aeration discs.

BACKGROUND ART

Aeration discs are known in the art for the introduction of air to a liquid. Aeration discs are typically used to aerate water such as that which may be present in a sewerage treatment pond; although the use of such discs should not be seen to be limited to such use as they may be used to promote flow and aeration in any still water.

Aeration disc efficiency lies in their ability to introduce air into the water, promote flow of the water as well as to minimize spray and/or splashing. It will be appreciated that

spraying/splashing water, particular in regard to waste water, should be avoided. It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

Throughout this specification, the word "comprise", or variations thereof such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only. DISCLOSURE OF THE INVENTION

According to one aspect of the present invention there is provided a component of a water aeration disc including: a hub portion defining, in use, a rotational axis through the center of the disc, a fluid engaging surface on each side of the disc component, the fluid engaging surfaces of the disc component including a plurality of fluid engaging structures, wherein each fluid engaging structure defines a raised surface on one side of the disc and a recessed surface on the opposite side of the disc, and wherein the recessed surface of a fluid engaging structure on one side of the disc is formed into a back of the raised surface on the opposite side of the disc, and wherein the raised fluid engaging structures include a front which, in use, leads into a fluid and is configured to substantially prevent splashing upon entry into the fluid.

According to a second aspect of the present invention there is provided a water aeration disc including: a hub portion providing a rotational axis through the center of the disc, a fluid engaging surface on each side of the disc, the fluid engaging surfaces of the disc including a plurality of fluid engaging structures, wherein each fluid engaging structure defines a raised surface on one side of the disc and a recessed surface on the opposite side of the disc, wherein the recessed surface of a fluid engaging structure on one side of the disc is formed into a back of the raised surface on the opposite side of the disc, and wherein the raised fluid engaging structures include a front which, in use, leads into a fluid and is configured to substantially prevent splashing upon entry into the fluid.

According to a third aspect of the present invention there is provided a system for aerating a fluid, the system including:

• a platform;

• a water aeration disc of the type defined in the preceding statement, the water aeration disc mounted onto the platform to drive shaft; and

• a drive mechanism, wherein the drive mechanism is configured to provide rotational motion to the drive shaft, and wherein the shaft is positioned to locate the water aeration disc partially into the fluid. In some embodiments the platform may be a floating platform, in yet other embodiments the platform may form part of a structure such as the sides of a water race, the nature of the platform should therefore not be seen as being limiting.

According to a fourth aspect of the present invention there is provided a method of aerating a fluid using an aeration disc, the water aeration disc including a hub portion providing a rotational axis through the center of the disc, a fluid engaging surface on each side of the disc each of which includes a plurality of fluid engaging structures, each fluid engaging structure defining a raised surface on one side of the disc and a recessed surface on the opposite side of the disc, the recessed surface of a fluid engaging structure on one side of the disc formed into a back of the raised surface on the opposite side of the disc, and wherein the raised fluid engaging structures include a front which, in use, leads into a fluid and is configured to substantially prevent splashing upon entry into the fluid, the method including the steps of: a) rotating at least a portion of the disc having fluid engaging surfaces on it through air and a first fluid, wherein at least a portion of the air is carried into and is mixed with the first fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects of the present invention will become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 is a side view of a preferred embodiment of a component of an aeration disc;

Figure 2 is a top view of the aeration disc component shown in Figure 1 ;

Figure 3 is a bottom view of the aeration disc component shown in Figures 1 and 2;

Figure 4 is a front view of the aeration disc component shown in Figures 1 to 3; Figure 5 is an isometric view of the aeration disc component shown in Figures 1 to 4;

Figure 6 is a detail view of the hub of the aeration disc component shown in Figures 1 to 5;

Figure 7a is a detail view of the fluid engaging surface of the aeration disc component shown in Figures 1 to 5;

Figure 7b is a plan view of a raised surface of the aeration disc component shown in Figure 7a; Figure 7c is a profile view of a raised surface of the aeration disc component shown in Figure 7a; Figure 8 is a side view of a complete disc formed from the component of Figure 1 ;

Figure 9 is a front view of the complete disc of figure 8, and

Figure 10 is an isometric view of the complete disc of Figure 9.

BEST MODES FOR CARRYING OUT THE INVENTION With reference to Figures 1 to 5 there is shown a component of an aeration disc as generally designated by arrow 1. The disc component 1 includes a hub portion 2. The hub portion, shown in detail in Figure 6, defines a rotational axis A, which is through the center of the assembled disc, as shown in Figures 8 and 9. The disc component includes a leading edge connection 3 and a trailing edge connection 4. When forming a complete disc the leading edge connection 3 of one disc component is configured to attach to the trailing edge connection 4 of an adjacent disc component. The embodiment shown in the figures includes 4 disc components; however it will be appreciated that any number of components may be used to form a disc. In other embodiments the disc may be formed as a single unitary structure, (not shown).

The features of the disc that facilitate aeration are the same for both the unitary structure and the component form. The skilled reader will appreciate that the following description made with reference to the figures depicting the component form are interchangeable with the unitary form of the invention.

The aeration disc 1 includes a fluid engaging surface on each side of the disc, as generally indicated by arrow 5. The fluid engaging surfaces, shown in detail in Figure 7, include a plurality of fluid engaging structures 6 arranged in a common rotational direction R on the fluid engaging surfaces 5. Each fluid engaging structure 6 defines a raised surface 8 on one side of the disc and a recessed surface 7 on the opposite side of the disc. This structure is achieved by forming the recessed surfaces 7 into the back of a raised surface 8 on the opposite side of the disc. Adjacent fluid engaging surfaces alternate between raised surfaces 8 and recessed surfaces 7. The fluid engaging structures 6 are also arranged in arcs radiating from the hub over the fluid engaging surfaces as well as in a number of concentric rings of alternating raised surfaces 8 and recessed surfaces 7.

The raised surfaces 8 are formed as V-shaped wedges that project outward from the fluid engaging surfaces, as shown in Figure 7. The V-shaped wedges also include one or more grooves 9 that diverge from a relatively narrow leading width 9a to a wider trailing width 9b with respect to the rotational direction R of the fluid engaging surfaces. The grooves 9 are substantially aligned with a trailing recessed surface 7 so as to provide a channel for a fluid (not shown) to flow through and into the recessed surface 7.

The 'V shape of the raised surfaces 8 creates a channel 10 between adjacent raised surfaces 8 that tapers from a wider end 10a to a narrower end 10b in the rotational direction R. Channel 10 is configured to create pressure differentials in air adjacent the surface of the disc when the fluid engaging surfaces 5 are rotating through the air. With respect to atmospheric pressure the recessed portions 7 experience a localized pressure drop due the channel 10 forming an open sided venturi. The venturi effect of the channel is due to the air flowing through the channel 10 accelerating as it passes from the wider end 10a to the narrower end 10b, therefore also resulting in a pressure drop from the wider end 10a to the narrower end 10b. In addition to air flowing through the channel 10 air also flows over, and around, the raised surfaces 8. The sides of the raised fluid engaging surface provide "over-square" angles, shown as 100, 101 , 102, 103 in figure 7b, and as 104 in Figure 7c. The over-square angles generate a localized low pressure region adjacent the edge forming the over-square angle. As an air stream flows past an edge having an over square angle the air stream mixes with the relatively stationary air sitting behind the edge, pulling some of the stationary air free and into the flow. This action also has the effect of causing the air stream to slow and curve in the direction of the edge. In practice a low pressure zone is produced behind the raised surfaces 8 within a trailing recessed surface 7. The shape of the low pressure zone closely mirrors the shape of the raised surfaces 8 due to the curving of the air stream as it passes over the over-square angled edges. The raised surfaces 8 also includes protrusions 104 extending from the grooves 9, these also provide over- square edges shown as 101 , 103 and 104 in Figure 7b. In use, as the disc rotates the low pressure zones forms air pockets that are pulled down into the fluid to be aerated. The grooves 9 assist in the fluid flowing behind the raised surfaces 8 and releasing the air pockets into the fluid during the period a particular portion of the disc is swept through the fluid.

The edge outermost from the hub includes a plurality of reverse curvature flow elements 11. These promote, along with the fluid engaging structures being arranged in arcs radiating from the hub, an outward flow of fluid in the same plane as the disc. Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to".

The entire disclosures of all applications, patents and publications cited above and below, if any, are herein incorporated by reference.

Reference to any prior art in this specification is not, and should not be taken as, an

acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world.

The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features. Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present invention.

Claims

WHAT I CLAIM IS:

1. A component of an aeration disc including: a hub portion defining, in use, a rotational axis through the center of the disc, a fluid engaging surface on each side of the disc component, the fluid engaging surfaces of the disc component including a plurality of fluid engaging structures, wherein each fluid engaging structure defines a raised surface on one side of the disc and a recessed surface on the opposite side of the disc, and wherein the recessed surface of a fluid engaging structure on one side of the disc is formed into a back of the raised surface on the opposite side of the disc, and wherein the raised fluid engaging structures include a front which, in use, leads into a fluid and is configured to substantially prevent splashing upon entry into the fluid.

2. The aeration disc component of claim 1 wherein adjacent fluid engaging structures formed into the fluid engaging surfaces alternate between raised fluid engaging structures and recessed fluid engaging structure.

3. The aeration disc component of either one of claim 1 or claim 2, wherein the raised surfaces of the fluid engaging structures are formed as V-shaped wedges that project outward from the fluid engaging surfaces.

4. The aeration disc component of claim 3, wherein the V-shaped wedges are arranged in arcs radiating from the hub over the fluid engaging surfaces.

5. The aeration disc component of either one of claim 3 or claim 4, wherein the V-shaped wedges include one or more grooves formed therein.

6. The aeration disc component of claim 5, wherein the grooves include walls that diverge from a relatively narrow leading width to a wider trailing width with respect to the rotational direction of the fluid engaging surfaces.

7. The aeration disc component of either one of claim 5 or claim 6, wherein the grooves formed in each of the V-shaped wedges are substantially aligned with a trailing recessed surface.

8. The aeration disc component of any one of claims 1 to 7 wherein concentric rings of alternating raised surfaces and recessed surfaces are formed on the fluid engaging surfaces.

9. The aeration disc component of any one of claims 1 to 8 wherein adjacent raised surfaces provide a channel therebetween which tapers from a wider end to a narrower end in the common rotational direction.

10. The aeration disc component of claim 9 wherein the channel forms an open sided

venturi.

11. The aeration disc component of any one of the claims 1 to 10 wherein the edge

outermost from the hub includes a plurality of reverse curvature flow elements.

12. The aeration disc component of any one of claims 1 to 11 wherein the disc can be

formed from two or more components.

13. The aeration disc component of claim 12 wherein each disc component can form a sector of the disc.

14. The aeration disc component of claim 13 wherein each sector includes a leading edge connection and at a trailing edge connection.

15. The aeration disc component of claim 14 wherein the leading edge connection of one disc component is configured to attach to the trailing edge connection of an adjacent disc component.

16. A aeration disc constructed from interconnection of two or more of the disc components as claimed in claim 15.

17. A water aeration disc including: a hub portion providing a rotational axis through the center of the disc, a fluid engaging surface on each side of the disc, the fluid engaging surfaces of the disc including a plurality of fluid engaging structures, wherein each fluid engaging structure defines a raised surface on one side of the disc and a recessed surface on the opposite side of the disc wherein the recessed surface of a fluid engaging structure on one side of the disc is formed into a back of the raised surface on the opposite side of the disc, and wherein the raised fluid engaging structures include a front which, in use, leads into a fluid and is configured to substantially prevent splashing upon entry into the fluid.

18. The water aeration disc of claim 17 wherein adjacent fluid engaging structures formed into the fluid engaging surfaces alternate between raised fluid engaging structures and recessed fluid engaging structure.

19. The water aeration disc of either one of claim 17 or claim 18 , wherein the raised surfaces of the fluid engaging structures are formed as V-shaped wedges that project outward from the fluid engaging surfaces.

20. The water aeration disc claim 19, wherein the V-shaped wedges are arranged in arcs radiating from the hub over the fluid engaging surfaces.

21. The water aeration disc of either one of claim 19 or claim 20, wherein the V-shaped wedges include one or more grooves formed therein.

22. The water aeration disc of claim 21 , wherein the grooves include walls that diverge from a relatively narrow leading width to a wider trailing width with respect to the rotational direction of the fluid engaging surfaces.

23. The water aeration disc of either one of claim 21 or claim 22, wherein the grooves

formed in each of the V-shaped wedges are substantially aligned with a trailing recessed surface.

24. The water aeration disc of any one of claims 17 to 23 wherein concentric rings of

alternating raised surfaces and recessed surfaces are formed on the fluid engaging surfaces.

25. The water aeration disc of any one of claims 17 to 24 wherein adjacent raised surfaces provide a channel therebetween which tapers from a wider end to a narrower end in the common rotational direction.

26. The water aeration disc of claim 25 wherein the channel forms an open sided venturi.

27. The water aeration disc of any one of the claims 17 to 26 wherein the edge outermost from the hub includes a plurality of reverse curvature flow elements.

28. The water aeration disc of any one of claims 17 to 27 wherein the disc is formed from two or more components.

29. The water aeration disc of claim 28 wherein each of the two or more components forms a sector of the disc.

30. The water aeration disc of either one of claims 28 or 29 wherein each of the two or more components includes a leading edge connection and a trailing edge connection.

31. The water aeration disc of 30 wherein the leading edge connection of one disc

component is configured to attach to the trailing edge connection of an adjacent disc component.

32. A system for aerating a fluid, the system including: • a platform;

• a water aeration disc of the type defined in any one of claims 17 to 31 , the water aeration disc mounted onto the platform to drive shaft; and

• a drive mechanism, wherein the drive mechanism is configured to provide rotational motion to the drive shaft, and wherein the shaft is positioned to locate the water aeration disc partially into the fluid.

33. A method of aerating a fluid using an aeration disc, the water aeration disc including a hub portion providing a rotational axis through the center of the disc, a fluid engaging surface on each side of the disc each of which includes a plurality of fluid engaging structures, each fluid engaging structure defining a raised surface on one side of the disc and a recessed surface on the opposite side of the disc, the recessed surface of a fluid engaging structure on one side of the disc formed into a back of the raised surface on the opposite side of the disc, and wherein the raised fluid engaging structures include a front which, in use, leads into a fluid and is configured to substantially prevent splashing upon entry into the fluid, the method including the steps of: b) rotating at least a portion of the disc having fluid engaging surfaces on it through air and a first fluid, wherein at least a portion of the air is carried into and is mixed with the first fluid.

34. The method of claim 39 wherein the fluid is water.