Patent ID: 8894048

Claim:
A gas diffuser ( 10 ) comprising a grid of aeration pipes ( 12 , 12 ′, 12 ″, 12 ″′) spaced apart and in parallel alignment with each other within a common horizontal plane and a manifold ( 14 ) in fluid communication with the aeration pipes, wherein an aeration pipe ( 12 ) comprises: a length (L) extending between two ends ( 16 , 18 ) and defining an axis (Z), a hydrodynamic diameter (D h ), an elliptical cross-sectional area defining a vertical plane comprising a vertical (Y) and horizontal (X) axis intersecting through a center (C) which are perpendicular to axis (Z), an outer circumference defined by a first arc ( 20 ) comprising 30° located below the (X) axis and bisected by the (Y) axis, and a second arc ( 22 ) comprising 330° which is non-overlapping with the first arc ( 20 ) and wherein the second arc ( 22 ) comprises four non-overlapping 15° sectors, a plurality (N) of discharge holes ( 26 , 28 , 30 , 32 ) spaced along the length (L) at four or more distinct positions about the second arc ( 22 ) within said sectors and a plurality (M) of drainage holes ( 34 ) spaced along the length (L) within the first arc ( 20 ); wherein each of the four sectors of the second arc ( 22 ) comprise: at least 10 discharge holes having a minimum hydraulic diameter (d min ) of equal to or greater than 0.001 m, a value (y) equal to the average position along the Y axis of all discharge holes within the sector measured in meters, and a value (F) equal to the mean value of the hydraulic diameter (d) to the fourth power for all discharge holes within the sector measured in meters; wherein the following relationship applies for any two of the four sectors: Abs[1− F i /F ii +2.6×10 8 m −5 N 2 ( y ii −y i ) F i )]≦0.5 wherein “i” and “ii” refer to higher and lower sectors along the Y axis, respectively.