Aeration discs and methods for using same
Aeration discs used in water treatment and methods of using same are disclosed. According to one or more embodiments, an aeration disc may comprise projections and depressions located on at least one of its surfaces. The aeration discs may be incorporated into aeration devices and water treatment systems.
1. An aeration disc, comprising:
a drive shaft opening;
a plurality of projections on a disc surface, each of the plurality of projections defining a recess in a leading portion to facilitate cup-like operation and comprising a tapered trailing portion, the plurality of projections being arranged in a series of clusters on the disc surface in a spoke pattern emanating from the drive shaft opening with each cluster comprising a plurality of rows of projections positioned in a parallel manner; and
a plurality of depressions on the disc surface, each of the plurality of depressions comprising a tapered leading portion and a trailing portion,
wherein each depression is positioned contiguous to the leading portion of one of the plurality of projections to increase an effective projection height, and wherein each depression and its corresponding projection forms a void volume in which liquid is entrained during operation.
2. The aeration disc of claim 1 , wherein the recesses are semi cylindrical.
3. The aeration disc of claim 1 , wherein the disc surface has an increased surface area of more than 40% in comparison to an aeration disc without the contiguous projections and depressions positioned on the disc surface.
4. The aeration disc of claim 1 , further comprising a plurality of dimples in the disc surface.
5. The aeration disc of claim 1 , wherein each of the plurality of rows of projections within each cluster comprises a different number of projections.
6. The aeration disc of claim 1 , wherein the drive shaft opening has a complimentary mating shape to a drive shaft that the drive shaft opening is configured to receive.
7. The aeration disc of claim 1 , wherein the aeration disc comprises two or more sections joined to form the aeration disc.
8. The aeration disc of claim 1 , wherein the projections have tapered backs.
9. The aeration disc of claim 1 , wherein side surfaces of the projections have a half-trapezoidal shape.
10. The aeration disc of claim 1 , wherein the projections are placed in a repeating pattern of four rows.
11. The aeration disc of claim 5 , wherein the longest row of each cluster is oriented perpendicular to the edge of the aeration disc at the point on the edge of the aeration disc closest to the end of the longest row.
12. The aeration disc of claim 5 , wherein the cluster is repeated ten times over half of an aeration disc.
13. The aeration disc of claim 5 , wherein the projections are offset among adjacent rows.
14. A method of retrofitting an aeration device, comprising:
removing one or more used aeration discs from a drive shaft; and
securing one or more of the aeration discs of claim 1 to the drive shaft.
15. The method of claim 14 , wherein securing further comprises placing two of more sections of the one or more aeration discs around the drive shaft and joining the two or more sections together to form the one or more aeration discs.
16. An aeration device, comprising:
a motor or gearbox;
a drive shaft coupled to the motor or gearbox; and
one or more of the aeration discs of claim 1 secured to the drive shaft.
17. A wastewater biological treatment system, comprising an oxidation ditch having one or more of the aeration devices disclosed in claim 16 .