Aeration system for liquid

• US 7,121,532 B2
• Filed: 11/30/2004
• Issued: 10/17/2006
• Est. Priority Date: 11/12/2004
• Status: Expired due to Fees

• Current Assignee: Ross A. Oades
• Original Assignee: Ross A. Oades
• Inventors: Oades, Ross A.
• Primary Examiner(s): BUSHEY, CHARLES S
• Application Number:
  US10/999,141
• Publication Number:
  US 20060103036A1
• Time in Patent Office: 686 Days
• Field of Search: 261/23.1, 261/30, 261/122.1, 261/123, 261/122.2, 261/124, 962/62, 963/43, 963/44, 963/45, 963/46, 963/50, 96352-354, 963/56, 963/58
• US Class Current: 261/23.1
• CPC Class Codes: B01F 2101/305 Treatment of water, waste water or sewage
• CPC Class Codes: B01F 23/231122 the flow guiding elements being dome-shaped elements, i.e. for trapping air, e.g. cap-, umbrella- or inversed cone-shaped
• CPC Class Codes: B01F 23/23113 characterised by the disposition of the bubbling elements in particular configurations, patterns or arrays
• CPC Class Codes: B01F 23/23121 having injection means, e.g. nozzles with circumferential outlet
• CPC Class Codes: B01F 23/231231 the outlets being in the form of perforations
• CPC Class Codes: C02F 3/20 using diffusers
• CPC Class Codes: Y02W 10/10 Biological treatment of water, waste water, or sewage

Abstract

An aeration tank used in a method of treating effluent includes a pipe for transporting the effluent from the source to the tank bottom and a discharge duct having a siphon effect for tapping off an overflow from the tank as more effluent is added from the source. An array of generally horizontal pipes is located in the tank having a series of exit holes along their length and connected to an air plenum at one side wall for feeding air into the end of each of the pipes, the pipes being arranged in columns one above another such that the air escapes from the pipes of the array through the holes to inject air into the effluent in the tank at positions spaced transversely, longitudinally and vertically. The pipes have flat upper discharge surfaces. Above each pipe is provided a collector channel which collects bubbles as they get too large and channels them to one end to be replaced by fresh small bubbles from a next above pipe.

Claims

1. Apparatus for aeration of liquid comprising:

a tank for receiving the liquid from a source having a tank bottom and tank sides for receiving and containing a quantity of the liquid during aeration;

a liquid supply pipe for transporting the liquid from the source into the tank arranged to discharge the liquid adjacent the tank bottom;

a discharge duct for removing liquid from a top of the tank to maintain a desired level of the liquid in the tank as more liquid is added from the source;

an array of aeration pipes in the tank above the bottom and below the level of the liquid so that the aeration pipes are located in the liquid in the tank;

each aeration pipe having an upper discharge surface with an array of air exit holes at spaced positions along its length and at spaced positions across its width;

an air feed system including an air pump for feeding air into one end of each of the pipes for discharge of the air through the air exit holes into the liquid as bubbles of the air in the liquid;

the array of aeration pipes being arranged such that each of the aeration pipes extends at least partly across the tank in a first direction of the tank;

the array of aeration pipes being arranged such that the aeration pipes are arranged at spaced positions across the tank in a second direction of the tank transverse to the first direction;

the array of aeration pipes being arranged such that the aeration pipes are arranged at different depths in the tank so as to define lower ones of the aeration pipes in the tank and upper ones of the aeration pipes in the tank at a death in the liquid higher than the lower ones of the aeration pipes;

such that liquid flows between and over the aeration pipes in a path from the supply pipe to the discharge duct;

and such that the air escapes from the aeration pipes of the array through the holes to inject air into the liquid in the tank at positions spaced in the tank both in the first and second directions and spaced vertically in the tank;

and a plurality of collecting channels each located in the tank above a respective one of the lower ones of the aeration pipes;

each of the collecting channels being arranged to collect bubbles rising from the respective one of the aeration pipes and being inclined so as to transport the bubbles as a stream of air to a location in the tank separated from the path of the liquid;

at least some of the upper ones of the aeration pipes being located in the tank above respective ones of the collecting channels so as to discharge the air from the upper ones of the aeration pipes through the air exit holes as bubbles into the liquid from which the bubbles of the lower ones of the aeration pipes have been removed by the collecting channels.

2. The apparatus according to claim 1 wherein the collecting channels are inclined upwardly toward said location at one side of the tank.

3. The apparatus according to claim 1 wherein each collecting channel is defined by an underside of a respective one of the upper ones of the aeration pipes.

4. The apparatus according to claim 1 wherein each aeration pipe has a generally flat upper surface spanning across a part of the width of the tank.

5. The apparatus according to claim 4 wherein the aeration pipes overlap in width and are staggered vertically to form a labyrinth path for the flow of the liquid from the bottom of the tank toward the top of the tank.

6. The apparatus according to claim 1 wherein the aeration pipes are parallel and coextensive.

7. The apparatus according to claim 1 wherein the air feed system includes a plenum formed at the end of each of the aeration pipes having an opening through one side wall into the plenum.

8. The apparatus according to claim 1 wherein the discharge duct defines a liquid level and wherein the aeration pipes have a top end below the liquid level.

9. The apparatus according to claim 1 wherein the discharge duct includes a portion which extends downwardly within the tank from an apex with a bottom entry mouth and an exterior portion depending downwardly from the apex outside the tank so as to form a siphon effect at the mouth.