Air diffuser and flushing method thereof

• US 20030001295A1
• Filed: 07/22/2002
• Published: 01/02/2003
• Est. Priority Date: 12/04/2000
• Status: Active Grant

• Current Assignee: Kubota Corporation
• Original Assignee: Kubota Corporation
• Inventors: Okajima, Yasunobu, Uejima, Tatsuya, Izumi, Kiyoshi, Nagano, Masaaki
• Granted Patent: US 6,843,470 B2
• Time in Patent Office: Days
• US Class Current: 261/124
• CPC Class Codes: B01D 2321/185 Aeration
• CPC Class Codes: B01D 2321/2066 Pulsated flow
• CPC Class Codes: B01D 61/18 Apparatus therefor
• CPC Class Codes: B01D 63/0821 Membrane plate arrangements for submerged operation
• CPC Class Codes: B01D 65/08 Prevention of membrane fouling or of concentration polarisation
• 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 23/23123 consisting of rigid porous or perforated material
• CPC Class Codes: B01F 23/231231 the outlets being in the form of perforations
• CPC Class Codes: B01F 23/231265 being tubes, tubular elements, cylindrical elements or set of tubes
• CPC Class Codes: B01F 23/29 Mixing systems, i.e. flow charts or diagrams
• CPC Class Codes: B01F 33/40512 involving gas diffusers at the bottom
• CPC Class Codes: B01F 35/20 Measuring; Control or regulation
• CPC Class Codes: C02F 1/444 by ultrafiltration or microfiltration
• CPC Class Codes: C02F 3/12 Activated sludge processes
• CPC Class Codes: C02F 3/1273 Submerged membrane bioreactors
• CPC Class Codes: C02F 3/20 using diffusers
• CPC Class Codes: C02F 3/302 Nitrification and denitrification treatment C02F3/308 takes precedence
• CPC Class Codes: Y02W 10/10 Biological treatment of water, waste water, or sewage
• CPC Class Codes: Y10S 261/70 Sewage aerators; diffusers

Abstract

An air diffuser (2) comprises a diffuser tube (5) immersed sidewardly in a tank (1), a flushing pipe (9) opening at its tip an outlet (11) at an upper position of the diffuser tube, and a flushing valve (12) disposed in the flushing pipe (9). The diffuser tube (5) is made up of a main pipe (6) communicated at its basal end to an air supply source (8) and communicated at its tip to the flushing pipe (9), and a plurality of branch pipes (7) being communicated to the main pipe (6) and opening at their tip as a blowhole (10) at a lower position of the main pipe (6). During air diffusion, air is supplied from the air supply source (8) with tile flushing valve (12) closed, and the air is diffused from the blowholes (10). During flushing, air is supplied from the air supply source (8) with the flushing valve (12) opened and an intra-tank mixed liquor is sucked from the openings of the diffuser tube (5), thereby flushing the inside of the diffuser tube (5) with the sucked intra-tank mixed liquor. The intra-tank mixed liquor is then joined with air to come off together from the outlet (11) of the flushing pipe (9). Air diffusion from the blowholes (10) and the flushing of the diffuser tube (5) are alternately repeated by utilizing pulsation to be caused by pressure variations in the diffuser tube (5).

Claims

1. An air diffuser comprising:

a diffuser tube having at its lower part a plurality of blowholes and being communicated at its basal end to an air supply source, the diffuser tube being immersed sidewardly in a tank;

a flushing pipe being communicated at its basal end to a tip of the diffuser tube and opening at its tip as an outlet at an upper position of the diffuser tube; and

a flushing valve disposed in the flushing pipe.

4. The air diffuser according to one of claims 1 to 3, further comprising:

a sensor means to measure the amount of waste water flow to the tank; and

a control means to open the flushing valve at a particular time when the sensor means detects that the quantity of waste water flow is below a predetermined value.

5. The air diffuser according to one of claims 1 to 3, further comprising;

a control means to open the flushing valve at predetermined time-spaced intervals at which a timer is set.

6. A method of flushing an air diffuser in an air diffuser according to one of claims 1 to 3, characterized in that during air diffusion, air is supplied from the air supply source with the flushing valve closed and the air is diffused from the blowholes, and, during flushing, air is supplied from the air supply source with the flushing valve opened and an intra-tank mixed liquor is sucked from the openings of the diffuser tube, so that the inside of the diffuser tube is flushed with the sucked intra-tank mixed liquor and the intra-tank mixed liquor is then joined with air to come off together from the outlet of the flushing pipe.

7. The method of flushing an air diffuser according to claim 6 wherein air diffusion from the blowholes and the flushing of the diffuser tube are alternately repeated by utilizing pulsation to be caused by pressure variations in the diffuser tube during flushing.

2. An air diffuser comprising:

a diffuser tube immersed sidewardly in a tank;

a flushing pipe opening at its tip as an outlet at an upper position of the diffuser tube; and

a flushing valve disposed in the flushing pipe,

the diffuser tube having;

a main pipe communicated at its basal end to an air supply source and communicated at its tip to the flushing pipe; and

a plurality of branch pipes being communicated to the main pipe and being opening at its tip as a blowhole at a lower position of the main pipe.

3. An air diffuser comprising:

a diffuser tube immersed sidewardly in a tank;

a flushing pipe opening at its tip as an outlet at an upper position of the diffuser tube; and

a flushing valve disposed in the flushing pipe,

the diffuser tube having;

a main pipe communicated at its basal end to an air supply source and communicated at its tip to the flushing pipe; and

a plurality of branch pipes being communicated to the main pipe, the branch pipes opening at their tip at a lower position of the main pipe and having a plurality of blowholes of which aperture is smaller than the opening at their tip.