US 4,734,197 A · Jet aerator header assemblies and methods for use thereof in total, partial, and non-barriered oxidation ditches

Abstract

A jet aerator header assembly is provided for the deep oxygen contact duct of a partial, total, or non-barriered oxidation ditch having an endless channel. The header assembly may be vertically installed in the bottom of the contact duct or at an angle in the intake portion thereof as a mid-duct header assembly; it can additionally be installed in a horizontal position at the inlet of the contact duct as an inlet header assembly. Each header assembly comprises a liquid header, an air header, a plurality of jet aerators which are flow connected to both headers, stiffener plates which rigidly attach the headers to each other and to the jet aerators, and pipes connecting the headers to respective liquid and air supply lines. The mid-duct header assembly is slideably mounted within an access duct which is accessible from the surface. The mid-duct header assembly can be operated to provide: (1) a base level of dissolved oxygen in the mixed liquor being discharged from the contact duct, and (2) a minimum circulation velocity within the endless channel of the oxidation ditch. The inlet header assembly can then be selectively operated to provide the additional amount of dissolved oxygen in the discharge mixed liquor that is required for aerobic treatment of the wastewater entering the endless channel at that time and season of the year. Air and liquid can be separately and selectively controlled for both mid-duct and inlet headers. Such operation provides separate control of mixed-liquor circulation velocity and of mixed-liquor aeration.

Claims23

Dependent claims

A jet aerator header assembly that is installd within and removable from, a deep oxygen contact duct which is mounted beneath and in flow communication with an endless channel, containing mixed liquor in translational movement, of a total, partial, or non-barriered oxidation ditch having a surface and a downflow pump, whereby at least a portion of said liquor flows through said duct, said assembly comprising:

A. a liquid header;
B. an air header;
C. a plurality of jet aerators which are flow connected to said liquid header and to said air header, said jet aerators being selectively oriented with respect to flow directions of said mixed liquor after said installation within said duct;
D. stiffening means for rigidly connecting said liquid header, said air header, and said jet aerator;
E. connecting means between said liquid header and a liquid supply line, said connecting means having sufficient length to extend from said surface to said contact duct;
F. connecting means between said air header and an air supply line;
and
G, means for selectively installing said headers, said jet aerators, and said stiffening means within said contact duct.

5 more elements

A method for controllably and independently pumping and aerating a stream of mixed liquor flowing through a deep oxygen contact duct of a partial, total, or non-barriered oxidation ditch comprising an endless channel, said contact duct having an inlet end and a discharge end and an axis therebetween, comprising the following steps:

A. providing a jet aerator header assembly at said inlet end;
B. providing at least one jet aerator mid-duct header assembly between said inlet end and said discharge end, each said header assembly comprising:
(1) a liquid header,
(2) an air header which is disposed adjacent to said liquid header,
(3) a plurality of jet aerators which are flow connected to said liquid header and to said air header,
(4) means which rigidly attach said headers to said plurality of jet aerators, and
(5) means respectively connecting said liquid and air headers to liquid and air supply means;
C. operating said at least one mid-duct header assembly to provide:
(1) oxygen transfer from air bubbles to said mixed liquor stream to create a base level of dissolved oxygen in said mixed liquor stream, and
(2) a minimum circulation velocity within said endless channel;
and
D. selectively operating said inlet header assembly to provide the additional amount of dissolved oxygen in said mixed liquor that is required for treatment of a stream of inflowing wastewater.

9 more elements

Dependencies are inferred from the claim text.

Jet aerator header assemblies and methods for use thereof in total, partial, and non-barriered oxidation ditches

Life of this patent

Jet aerator header assemblies and methods for use thereof in total, partial, and non-barriered oxidation ditches

Life of this patent

Abstract

Claims23