US4681682A — Air flotation clarifier

Claim 1

Independent Claim 149 words

A clarifier comprising an elongated settling tank for a pond of liquid having an inlet at one end, an outlet at the other end, and an overflow trough intermediate said ends, suction means for removing sludge from the bottom of the tank, skimmers for pushing floating scum on a pond when in the tank into said trough, a pressure tank, a compressed air source discharging to the top of said pressure tank, an air-liquid mixer discharging to said pressure tank, a compressor receiving air from the top of said pressure tank discharging to said mixer, means feeding effluent from the outlet of said settling tank to said mixer, means feeding air saturated effluent from said pressure tank to the inlet end of said settling tank, and means projecting into said settling tank from the outlet end thereof for removing clarified liquid as it is formed in the settling tank.

Claim 2

Dependent Claim 149 words

A clarifier comprising an elongated settling tank for a pond of liquid having an inlet at one end, an outlet at the other end, and an overflow trough intermediate said ends, suction means for removing sludge from the bottom of the tank, skimmers for pushing floating scum on a pond when in the tank into said trough, a pressure tank, a compressed air source discharging to the top of said pressure tank, an air-liquid mixer discharging to said pressure tank, a compressor receiving air from the top of said pressure tank discharging to said mixer, means feeding effluent from the outlet of said settling tank to said mixer, means feeding air saturated effluent from said pressure tank to the inlet end of said settling tank, and means projecting into said settling tank from the outlet end thereof for removing clarified liquid as it is formed in the settling tank.

Claim 3

Dependent Claim 21 words

The clarifier of claim 1 wherein the compressor is a liquid ring compressor receiving effluent to maintain a liquid ring therein.

Claim 4

Dependent Claim 31 words

The clarifier of claim 1 wherein the outlet end of the tank has a low level outlet for effluent fed to the mixer and a high level outlet for clarified liquid.

Claim 5

Dependent Claim 24 words

The clarifier of claim 1 wherein the means feeding the effluent to the mixer is a pump maintaining a back pressure on the mixer.

Claim 6

Dependent Claim 46 words

The clarifier of claim 1 including a plurality of hollow closed periphery fingers projecting into the tank in side-by-side relation from the outlet end of the tank and having interior drain passages communicating with said outlet together with inlets for clarified liquid along the lengths thereof.

Claim 7

Dependent Claim 229 words

A portable clarifier which comprises a longitudinally elongated base frame having a bottom for resting on the floor and wheels at ends above said bottom selectively engageable with said floor to transport the clarifier to use sites, a longitudinally elongated open top settling tank supported on said base frame having a converging hopper lower portion with a sludge collecting trough along the length thereof, means for flowing liquid to be clarified into one end of the tank, means discharging clarified liquid from the opposite end of the tank, a bridge riding over the open top of the tank, means reciprocating said bridge along the length of said tank, suction heads in said trough suspended from said bridge to evacuate settled out sludge from the trough, a scum overflow trough extending across said tank, means discharging air saturated liquid into the inlet end of said tank intermediate the top and bottom thereof to release air bubbles floating lighter contaminants to the top of the tank, skimmers suspended from said bridge pushing scum which floats on top of a liquid when contained in the tank into said scum collecting trough, and closed periphery weir fingers projecting into the tank from the discharge end thereof receiving clarified liquid below the liquid level in the pond when in the tank as it is formed for discharge from said opposite end of the tank.

Claim 8

Dependent Claim 229 words

A portable clarifier which comprises a longitudinally elongated base frame having a bottom for resting on the floor and wheels at ends above said bottom selectively engageable with said floor to transport the clarifier to use sites, a longitudinally elongated open top settling tank supported on said base frame having a converging hopper lower portion with a sludge collecting trough along the length thereof, means for flowing liquid to be clarified into one end of the tank, means discharging clarified liquid from the opposite end of the tank, a bridge riding over the open top of the tank, means reciprocating said bridge along the length of said tank, suction heads in said trough suspended from said bridge to evacuate settled out sludge from the trough, a scum overflow trough extending across said tank, means discharging air saturated liquid into the inlet end of said tank intermediate the top and bottom thereof to release air bubbles floating lighter contaminants to the top of the tank, skimmers suspended from said bridge pushing scum which floats on top of a liquid when contained in the tank into said scum collecting trough, and closed periphery weir fingers projecting into the tank from the discharge end thereof receiving clarified liquid below the liquid level in the pond when in the tank as it is formed for discharge from said opposite end of the tank.

Claim 9

Dependent Claim 65 words

The portable clarifier of claim 6 wherein the base frame has upwardly inclined ends suspending the wheels out of contact with the floor when the bottom rests on the floor and accommodating lifting of one end of the frame to lower the wheels at the other end of the frame into contact with the floor for accommodating transport of the clarifier to the use sites.

Claim 10

Dependent Claim 49 words

The clarifier of claim 6 wherein the weir fingers are hollow upstanding triangles with top apices, side walls diverging from the apices, and a bottom wall connecting the divergent ends of the side walls, and each of said side walls having a row of holes along the length thereof.

Claim 11

Dependent Claim 25 words

The portable clarifier of claim 8, wherein the hollow triangular fingers have sloping apices increasing in height toward the discharge end of the settling tank.

Claim 12

Dependent Claim 256 words

A travelling bridge clarifier which comprises an elongated open top settling tank for containing a pond of liquid, a travelling bridge riding over the top of said tank, suction heads suspended from said bridge adjacent the bottom of the tank for removing sludge settled from a pond of liquid when contained in the tank, means for reciprocating said bridge along the length of the tank to move the suction heads for acting on the entire bottom of the tank, an upright diffuser baffle in said tank adjacent one end thereof, means at one end of the tank defining an open top inlet chamber discharging into the tank through said diffuser baffle at a level intermediate the top and bottom of the tank, an overflow trough for receiving scum floating on a pond of liquid when in the tank, a high level outlet and a low level outlet at the end of the tank opposite said one end, said high level outlet receiving clarified liquid from the top of the pond, said low level outlet receiving effluent below the top of the pond, a pressure tank, an air source discharging into the top of the tank a compressor receiving air from the top of the tank, an air-effluent mixer receiving air from said compressor and effluent from said low level outlet and discharging into the pressure tank to provide a pond of effluent saturated with air dissolved therein, and means discharging the air saturated effluent from the pressure tank into the settling tank behind said diffuser baffle.

Claim 13

Dependent Claim 256 words

A travelling bridge clarifier which comprises an elongated open top settling tank for containing a pond of liquid, a travelling bridge riding over the top of said tank, suction heads suspended from said bridge adjacent the bottom of the tank for removing sludge settled from a pond of liquid when contained in the tank, means for reciprocating said bridge along the length of the tank to move the suction heads for acting on the entire bottom of the tank, an upright diffuser baffle in said tank adjacent one end thereof, means at one end of the tank defining an open top inlet chamber discharging into the tank through said diffuser baffle at a level intermediate the top and bottom of the tank, an overflow trough for receiving scum floating on a pond of liquid when in the tank, a high level outlet and a low level outlet at the end of the tank opposite said one end, said high level outlet receiving clarified liquid from the top of the pond, said low level outlet receiving effluent below the top of the pond, a pressure tank, an air source discharging into the top of the tank a compressor receiving air from the top of the tank, an air-effluent mixer receiving air from said compressor and effluent from said low level outlet and discharging into the pressure tank to provide a pond of effluent saturated with air dissolved therein, and means discharging the air saturated effluent from the pressure tank into the settling tank behind said diffuser baffle.

Claim 14

Dependent Claim 14 words

The clarifier of claim 10 wherein the diffuser baffle is a perforated upstanding plate.

Claim 15

Dependent Claim 15 words

The clarifier of claim 10 including a liquid ring compressor discharging air into the mixer.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1990-07-20	1991-01-19	1991-07-21	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1994-07-20	1995-01-19	1995-07-21	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1998-07-20	1999-01-19	1999-07-21	$7700.00	Window Closed / Lapsed

Air flotation clarifier

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