Flotation apparatus and method for achieving flotation in a centrifugal field

Claim 2

A flotation apparatus for obtaining separation of particles in a centrifugal field comprising: a chamber having a generally circular cross-section and receiving a particulate suspension therein; inlet means for introducing a fluid under pressure tangentially into the chamber thereby creating a vortex in the chamber, the vortex forming a centrifugal field; and gas sparging means for introducing a gas into the vortex in the chamber, the gas forming finely dispersed bubbles and assisting in separating particles in the particulate suspension by flotation in the centrifugal field.

Claim 3

The flotation apparatus defined in claim 1 wherein the chamber comprises a vertically oriented, cylindricoconical vessel having a cylindrical section adjacent the inlet means and tapering downwardly into a frustoconical section.

Claim 4

The flotation apparatus defined in claim 2 wherein the gas sparging means comprises a gas plenum surrounding at least a portion of the outer wall of the chamber and said portion of the outer wall comprises a porous wall for admitting gas from the gas plenum into the chamber.

Claim 5

The flotation apparatus defined in claim 1 wherein the chamber comprises a cylindrical vessel.

Claim 6

The flotation apparatus defined in claim 4 wherein the cylindrical vessel comprises a coaxial inlet at a first end for introducing a particulate suspension into the chamber and a coaxial outlet at a second end for removing a product discharge from the chamber and said inlet means comprises a tangential inlet adjacent said second end, said inlet means discharging through a tangential discharge adjacent said first end.

Claim 7

The flotation apparatus defined in claim 5 wherein at least a portion of the cylindrical vessel between the tangential inlet and the tangential outlet comprises a gas plenum surrounding the cylindrical vessel and a porous wall forming at least a portion of the wall between the gas plenum and the cylindrical vessel, the porous wall admitting a gas from the gas plenum into the chamber.

Claim 8

The flotation apparatus defined in claim 5 wherein the tangential inlet further comprises mixing means for mixing a gas with a fluid introduced through the tangential inlet into the chamber.

Claim 9

A gas-sparged hydrocyclone for obtaining separation of particles in a centrifugal field comprising: a vertically oriented chamber, the chamber having a circular cross-section; inlet means for introducing a particulate suspension into the chamber, the inlet means comprising a tangential entry, the tangential entry imparting a vortex flow to the particulate suspension and thereby creating a centrifugal field in the chamber; an overflow means for removing an overflow product from the chamber, the overflow means comprising a vortex finder located at an upper end of the chamber and oriented coaxially with the chamber; an outlet means for removing an underflow product from the chamber, the outlet means comprising a discharge outlet at a lower end of the chamber and oriented coaxially with the chamber; and gas sparging means for introducing a gas into the chamber comprising a gas plenum surrounding the chamber and a porous wall between the gas plenum and the chamber for introducing gas from the gas plenum into the chamber.

Claim 10

A gas-sparged hydrocyclone for obtaining separation of particles in a centrifugal field comprising: a vertically oriented chamber, the chamber having a circular cross-section; inlet means for introducing a particulate suspension into the chamber, the inlet means comprising a tangential entry, the tangential entry imparting a vortex flow to the particulate suspension and thereby creating a centrifugal field in the chamber; an overflow means for removing an overflow product from the chamber, the overflow means comprising a vortex finder located at an upper end of the chamber and oriented coaxially with the chamber; an outlet means for removing an underflow product from the chamber, the outlet means comprising a discharge outlet at a lower end of the chamber and oriented coaxially with the chamber; and gas sparging means for introducing a gas into the chamber comprising a gas plenum surrounding the chamber and a porous wall between the gas plenum and the chamber for introducing gas from the gas plenum into the chamber.

Claim 11

The gas-sparged hydrocyclone defined in claim 8 wherein the chamber comprises an upper, cylindrical section and a lower, downwardly tapered conical section.

Claim 12

An air-sparged hydrocyclone comprising: a generally cylindrical vessel having a coaxial feed at a first end and a coaxial discharge at a second end; an inlet means for introducing a washing medium into the vessel, the inlet means located adjacent the second end and intersecting the vessel tangentially; an outlet means for removing particles and washing medium from the vessel, the outlet means located adjacent the first end and intersecting the vessel tangentially; a porous wall forming at least a portion of the vessel between the inlet means and the outlet means; and an air plenum enclosing the porous wall portion of the vessel.

Claim 13

An air-sparged hydrocyclone comprising: a generally cylindrical vessel having a coaxial feed at a first end and a coaxial discharge at a second end; an inlet means for introducing a washing medium into the vessel, the inlet means located adjacent the second end and intersecting the vessel tangentially; an outlet means for removing particles and washing medium from the vessel, the outlet means located adjacent the first end and intersecting the vessel tangentially; a porous wall forming at least a portion of the vessel between the inlet means and the outlet means; and an air plenum enclosing the porous wall portion of the vessel.

Claim 14

An air-sparged hydrocyclone comprising: a generally cylindrical vessel having a coaxial feed at a first end and a coaxial discharge at a second end; an inlet means located adjacent the second end and intersecting the vessel tangentially; an outlet means located adjacent the first end and intersecting the vessel tangentially; and sparging means for mixing a gas with a liquid introduced through the inlet means.

Claim 15

An air-sparged hydrocyclone comprising: a generally cylindrical vessel having a coaxial feed at a first end and a coaxial discharge at a second end; an inlet means located adjacent the second end and intersecting the vessel tangentially; an outlet means located adjacent the first end and intersecting the vessel tangentially; and sparging means for mixing a gas with a liquid introduced through the inlet means.

Claim 18

The method defined in claim 12, wherein the obtaining step comprises preparing said vessel with a cylindrical section and a conical section and orienting said vessel in a vertical orientation with said conical section providing a downward taper to the vessel.

Claim 19

The method defined in claim 13 wherein said preparing step further comprises creating said vortex and said centrifugal field in said vessel by injecting said feed tangentially into said cylindrical section of said vessel.

Claim 20

The method defined in claim 12, wherein the obtaining step comprises preparing said vessel as a cylindrical chamber.

Claim 21

The method defined in claim 15 wherein the preparing step further comprises inducting said feed into said vessel through a coaxial inlet and said forming step further comprises creating said centrifugal field by injecting a second fluid tangentially into the vessel.

Claim 22

The method defined in claim 16 wherein said preparing step further comprises forming a porous wall as a part of said cylindrical vessel and enclosing said porous wall in a gas plenum and injecting a gas phase into said vessel through said porous wall from said gas plenum.

Claim 23

The method defined in claim 16 wherein said preparing step further comprises mixing a gas phase with a second liquid phase and introducing said second liquid phase tangentially into said vessel thereby forming said vortex while introducing said gas phase into said vortex.