Mechanical aerator

Claim 3

In a paddle type aerator of the type used for the aeration of sewage, having an impeller positioned so as to contact the surface of the sewage, said impeller comprising: a. a shaft rotatable about a substantially vertical axis; and b. a plurality of elongated substantially horizontal open backward curved vane means extending outwardly from said shaft, said vane means curved such that as said impeller rotates about a substantially vertical axis a series of thin film waves eminate spirally outward and upward from the convex surface of said vane means, such that each particle of sewage contained therein moves radially outward from said axis of rotation.

Claim 4

In a paddle type aerator of the type used for the aeration of sewage, having an impeller positioned so as to contact the surface of the sewage, said impeller comprising: a. a shaft rotatable about a substantially vertical axis; and b. a plurality of elongated substantially horizontal open backward curved vane means extending outwardly from said shaft, said vane means curved such that as said impeller rotates about a substantially vertical axis a series of thin film waves eminate spirally outward and upward from the convex surface of said vane means, such that each particle of sewage contained therein moves radially outward from said axis of rotation.

Claim 5

In a paddle type aerator of the type used for the aeration of a liquid, having an impeller positioned so as to contact the surface of the liquid, said impeller comprising: a. a shaft rotatable about a substantially vertical axis; and b. a plurality of elongated substantially horizontal open backward curved vanes extending outwardly from said shaft, each of said vanes being contained within an area defined between first and second circular arcs, said first and second arcs both being generated from a point located on a reference line extending radially outward from said shaft and spaced a distance equal to (D-Rs)/2.83 from the center of said shaft, said first arc having a radius of curvature equal to (D-Rs)/2.4 and said second arc having a radius of curvature equal to (D-Rs)/3.2, where D is the diameter of the impeller in inches and Rs is the radius of the shaft in inches.

Claim 6

In a paddle type aerator of the type used for the aeration of a liquid, having an impeller positioned so as to contact the surface of the liquid, said impeller comprising: a. a shaft rotatable about a substantially vertical axis; and b. a plurality of elongated substantially horizontal open backward curved vanes extending outwardly from said shaft, each of said vanes being contained within an area defined between first and second circular arcs, said first and second arcs both being generated from a point located on a reference line extending radially outward from said shaft and spaced a distance equal to (D-Rs)/2.83 from the center of said shaft, said first arc having a radius of curvature equal to (D-Rs)/2.4 and said second arc having a radius of curvature equal to (D-Rs)/3.2, where D is the diameter of the impeller in inches and Rs is the radius of the shaft in inches.

Claim 7

In a paddle type aerator of the type used for the aeration of a liquid, having an impeller positioned so as to contact the surface of the liquid, said impeller comprising: a. a shaft rotatable about a substantially vertical axis; and b. a plurality of elongated substantially horizontal open backward curved vanes extending outwardly from said shaft, each of said vanes being a portion of a cylinder whose radius of curvature is substantially equal to (D-Rs)/2.83 , where D is the diameter of the impeller in inches and Rs is the radius of the shaft in inches.

Claim 8

In a paddle type aerator of the type used for the aeration of a liquid, having an impeller positioned so as to contact the surface of the liquid, said impeller comprising: a. a shaft rotatable about a substantially vertical axis; and b. a plurality of elongated substantially horizontal open backward curved vanes extending outwardly from said shaft, each of said vanes being a portion of a cylinder whose radius of curvature is substantially equal to (D-Rs)/2.83 , where D is the diameter of the impeller in inches and Rs is the radius of the shaft in inches.

Claim 9

In a sewage treatment apparatus including a container having an inlet and an outlet adapted for flow of sewage therethrough, aeration means having an impeller positioned so as to contact the surface of the liquid, and means to rotate said impeller, said impeller comprising: a. a shaft rotatable about a substantially vertical axis; and b. a plurality of circumferentially spaced elongated substantially horizontal open backward curved vane means extending outwardly from said shaft, said vane means curved such that as said impeller rotates about said substantially vertical axis the sewage particles that contact the convex surface of said vane means are thrown outward along a line substantially radial to said axis of rotation.

Claim 10

In a sewage treatment apparatus including a container having an inlet and an outlet adapted for flow of sewage therethrough, aeration means having an impeller positioned so as to contact the surface of the liquid, and means to rotate said impeller, said impeller comprising: a. a shaft rotatable about a substantially vertical axis; and b. a plurality of circumferentially spaced elongated substantially horizontal open backward curved vane means extending outwardly from said shaft, said vane means curved such that as said impeller rotates about said substantially vertical axis the sewage particles that contact the convex surface of said vane means are thrown outward along a line substantially radial to said axis of rotation.

Claim 11

The invention defined in claim 5 wherein said impeller discharges a series of thin film waves spiralling outward and upward therefrom.

Claim 12

The invention defined in claim 6 wherein each of said vane means being contained within an area defined between first and second circular arcs, said first and second arcs being generated from a point located on a reference line extending radially outward from said shaft and spaced a distance equal to (D-Rs)/2.83 from the center of said shaft, said first arc having a radius of curvature equal to (D-Rs)/2.4 and said second arc having a radius of curvature equal to (D-Rs)/3.2, where D is the diameter of the impeller in inches and Rs is the radius of the shaft in inches.

Claim 13

The invention defined in claim 6 wherein each of said vane means being a portion of a cylinder whose radius of curvature is substantially equal to (D-Rs)/2.83, where D is the diameter of the impeller in inches and Rs is the radius of the shaft in inches.