US4397741A
Expired / Lapsed
US
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Apparatus and method for separating particles from a fluid suspension
Assignee: University of Utah
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Filing: 1981-11-20
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Granted: 1983-08-09
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Expires: 2001-11-20
Abstract
Abstract An apparatus and method for separating particles from a fluid, particulate suspension by flotation in a centrifugal field. The apparatus includes a vertically oriented, cylindrical vessel having a tangential inlet and a tangential outlet. The particulate suspension is introduced into the vessel through the inlet and swirls around the inner surface of the vessel in a thin fluid layer. Air is sparged through a porous wall formed in the vessel and into the thin fluid layer of the particulate suspension. Small bubbles are generated at the surface of the porous wall. The directed motion of the particles in the thin layer of particulate fluid suspension results in a high probability for collision and a rapid flotation. The air bubbles and particles form bubble/particle aggregates which migrate towards the axial center of the apparatus and into a froth phase in the core of the apparatus. The particle-containing froth travels upwardly, countercurrently to the thin fluid layer, and is removed coaxially through a vortex finder.
Inventors
- 👤 Jan D. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:09
CPC Classifications
B; B03; B03D; B03D1/00; B03D1/14; B03D1/1418; B03D1/1425; B03D1/1493; B04; B04C; B04C5/00; B04C5/08; B04C5/10; B04C7/00; B04C9/00; B03D1/1431
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
128 words
An apparatus for separating particles from a particulate suspension by flotation in a centrifugal field, comprising: a generally vertically oriented vessel having a generally cylindrical configuration; an inlet at the upper end of the vessel for introducing a particulate suspension under pressure into the vessel in a generally tangential fashion; an outlet at the lower end of the vessel for directing fluid discharge from said particulate suspension out of the vessel in a generally tangential fashion, said inlet and outlet directing fluid flow so as to create a forced vortex in the vessel, said forced vortex forming a centrifugal field; and means for introducing air into said particulate suspension, the air forming small bubbles which separate the particles from the particulate suspension by flotation in the centrifugal field.
Claim 2
Independent Claim
128 words
An apparatus for separating particles from a particulate suspension by flotation in a centrifugal field, comprising: a generally vertically oriented vessel having a generally cylindrical configuration; an inlet at the upper end of the vessel for introducing a particulate suspension under pressure into the vessel in a generally tangential fashion; an outlet at the lower end of the vessel for directing fluid discharge from said particulate suspension out of the vessel in a generally tangential fashion, said inlet and outlet directing fluid flow so as to create a forced vortex in the vessel, said forced vortex forming a centrifugal field; and means for introducing air into said particulate suspension, the air forming small bubbles which separate the particles from the particulate suspension by flotation in the centrifugal field.
Claim 3
Dependent Claim
42 words
An apparatus as defined in claim 1 wherein the inlet is configurated so as to direct the particulate suspension around an inner surface of the vessel in such a manner that the particulate suspension forms a thin fluid layer within the vessel.
Claim 4
Dependent Claim
21 words
An apparatus as defined in claim 1 further comprising means for controlling flow rate of the fluid discharge through the outlet.
Claim 5
Dependent Claim
60 words
An apparatus as defined in claim 1 wherein at least a portion of a wall of the vessel comprises a porous wall, and wherein the air introducing means comprises an air plenum surrounding the porous wall portion of the vessel, the porous wall providing for the passage of air from the air plenum into the particulate suspension within the vessel.
Claim 6
Dependent Claim
44 words
An apparatus as defined in claim 1 wherein the air bubbles congregate within the vessel to form a froth and further comprising a vortex finder positioned at the upper end of the vessel so as to guide the froth coaxially out of the vessel.
Claim 7
Independent Claim
194 words
An apparatus for separating particles by flotation in a thin fluid layer, comprising: a generally vertically oriented vessel having a generally cylindrical configuration, at least a portion of a wall of the vessel comprising a porous wall; an inlet at the upper end of the vessel for introducing a particulate suspension under pressure into the vessel in a generally tangential fashion, the inlet being configurated so as to direct the particulate suspension into the vessel in such a manner that the particulate suspension forms a thin fluid layer around the inner surface of the wall of the vessel; an outlet at the lower end of the vessel for directing fluid discharge from the particulate suspension out of the vessel in a generally tangential fashion, the inlet and the outlet directing fluid flow so as to create a forced vortex in the vessel, the forced vortex forming a centrifugal field; means for controlling flow rate of the fluid discharge through the outlet; and an air plenum surrounding the porous wall portion of the vessel, the porous wall providing for the passage of air from the air plenum into the thin fluid layer within the vessel.
Claim 8
Independent Claim
194 words
An apparatus for separating particles by flotation in a thin fluid layer, comprising: a generally vertically oriented vessel having a generally cylindrical configuration, at least a portion of a wall of the vessel comprising a porous wall; an inlet at the upper end of the vessel for introducing a particulate suspension under pressure into the vessel in a generally tangential fashion, the inlet being configurated so as to direct the particulate suspension into the vessel in such a manner that the particulate suspension forms a thin fluid layer around the inner surface of the wall of the vessel; an outlet at the lower end of the vessel for directing fluid discharge from the particulate suspension out of the vessel in a generally tangential fashion, the inlet and the outlet directing fluid flow so as to create a forced vortex in the vessel, the forced vortex forming a centrifugal field; means for controlling flow rate of the fluid discharge through the outlet; and an air plenum surrounding the porous wall portion of the vessel, the porous wall providing for the passage of air from the air plenum into the thin fluid layer within the vessel.
Claim 9
Independent Claim
102 words
A method for separating particles from a fluid suspension by flotation in a centrifugal field, comprising the steps of: obtaining a generally vertically oriented vessel having a generally cylindrical configuration; introducing a fluid suspension into the upper end of the vessel in a generally tangential fashion; forming a centrifugal field in the vessel by creating a forced vortex in the vessel; sparging air into the fluid suspension, the air forming small bubbles which separate the particles from the fluid suspension leaving a fluid discharge; and directing the fluid discharge out of the lower end of the vessel in a generally tangential fashion.
Claim 10
Independent Claim
102 words
A method for separating particles from a fluid suspension by flotation in a centrifugal field, comprising the steps of: obtaining a generally vertically oriented vessel having a generally cylindrical configuration; introducing a fluid suspension into the upper end of the vessel in a generally tangential fashion; forming a centrifugal field in the vessel by creating a forced vortex in the vessel; sparging air into the fluid suspension, the air forming small bubbles which separate the particles from the fluid suspension leaving a fluid discharge; and directing the fluid discharge out of the lower end of the vessel in a generally tangential fashion.
Claim 11
Dependent Claim
22 words
A method as defined in claim 7 further comprising the step of regulating flow rate of the fluid discharge from the vessel.
Claim 12
Dependent Claim
31 words
A method as defined in claim 7 further comprising the step of maintaining the fluid suspension within the vessel as a thin fluid layer against an inner surface of the vessel.
Claim 13
Dependent Claim
50 words
A method as defined in claim 7 wherein at least a portion of a wall of the vessel comprises a porous wall and wherein the sparging step comprises introducing air through the porous wall and into the fluid suspension within the vessel, the air forming bubbles within the fluid suspension.
Claim 14
Dependent Claim
37 words
A method as defined in claim 10 further comprising the step of generating the air bubbles at the porous wall so as to promote directed collision between the air bubbles and the particles in the fluid suspension.
Claim 15
Dependent Claim
34 words
A method as defined in claim 7 further comprising the steps of forming a particle-containing froth within the vessel and removing the froth from a coaxial outlet formed in the top of the vessel.
Claim 16
Independent Claim
90 words
A method for separating particles from a fluid suspension by flotation in a centrifugal field, comprising the steps of: obtaining a vessel having a generally circular cross-section; introducing a fluid suspension into the vessel so as to form a thin layer against an inner surface of the vessel and so as to create a forced vortex in the vessel, the forced vortex forming a centrifugal field; and sparging air into the thin layer of fluid suspension, the air forming bubbles which separate the particles from the fluid suspension by flotation.
Claim 17
Independent Claim
90 words
A method for separating particles from a fluid suspension by flotation in a centrifugal field, comprising the steps of: obtaining a vessel having a generally circular cross-section; introducing a fluid suspension into the vessel so as to form a thin layer against an inner surface of the vessel and so as to create a forced vortex in the vessel, the forced vortex forming a centrifugal field; and sparging air into the thin layer of fluid suspension, the air forming bubbles which separate the particles from the fluid suspension by flotation.
Claim 18
Independent Claim
171 words
A method for separating particles from a fluid suspension of particles by flotation in a thin layer of the fluid suspension, comprising the steps of: obtaining a generally vertically oriented vessel having a generally cylindrical configuration, at least a portion of a wall of the vessel comprising a porous wall; introducing a fluid supension into the vessel in a generally tangential fashion such that the fluid suspension swirls around an inner surface of the wall of the vessel and forms a thin layer thereagainst; forming a centrifugal field in the vessel by creating a forced vortex in the vessel; sparging air through the porous wall and into the thin layer of fluid suspension within the vessel, the air forming small bubbles which separate the particles from the fluid suspension leaving a fluid discharge; directing the fluid discharge out of the vessel in a generally tangential fashion; regulating flow rate of the fluid discharge from the vessel; forming a particle-containing froth within the vessel; and removing the froth coaxially from the vessel.
Claim 19
Independent Claim
171 words
A method for separating particles from a fluid suspension of particles by flotation in a thin layer of the fluid suspension, comprising the steps of: obtaining a generally vertically oriented vessel having a generally cylindrical configuration, at least a portion of a wall of the vessel comprising a porous wall; introducing a fluid supension into the vessel in a generally tangential fashion such that the fluid suspension swirls around an inner surface of the wall of the vessel and forms a thin layer thereagainst; forming a centrifugal field in the vessel by creating a forced vortex in the vessel; sparging air through the porous wall and into the thin layer of fluid suspension within the vessel, the air forming small bubbles which separate the particles from the fluid suspension leaving a fluid discharge; directing the fluid discharge out of the vessel in a generally tangential fashion; regulating flow rate of the fluid discharge from the vessel; forming a particle-containing froth within the vessel; and removing the froth coaxially from the vessel.
Claim 20
Dependent Claim
54 words
A method as defined in claim 14 further comprising the step of generating the air bubbles at the porous wall so as to promote directed collision between the air bubbles and the particles in the fluid suspension, thereby increasing the rate of collision of the air bubbles with the particles in the fluid suspension.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-08 | 1987-02-07 | 1987-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-08 | 1991-02-07 | 1991-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-08 | 1995-02-07 | 1995-08-09 | $7700.00 | Window Closed / Lapsed |