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US4035164A Expired / Lapsed US ⏱️ 0.0 years remaining

Methods for removing charged and non-charged particles from a fluid by employing a pyrollectric filter

Assignee: 3M Co
•
Filing: 1974-11-29
•
Granted: 1977-07-12
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Expires: 1994-11-29
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Abstract

Abstract Processes for attracting charged and non-charged particles from a fluid by means of a pyroelectric filtering medium.

Inventors

  • 👤 Allen L. Taylor

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 22:56
CPC Classifications
B; B03; B03C; B03C3/00; B03C3/28; Y; Y10; Y10S; Y10S428/00; Y10S428/913

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 132 words
A process for removing charged and non-charged particles from a fluid flow by attracting said particles to a separator device wherein said device comprises a separating medium formed of a poled, temperature sensitive pyroelectric material having a first surface and a second surface wherein said pyroelectric material produces electrostatic charges on said surfaces when its ambient temperature is varied, the charges produced on the first surface of said pyroelectric material being opposite in polarity to the charges produced on the second surface thereof, which process comprises the steps of: (a) varying the ambient temperature of said separating medium; and (b) passing the fluid flow within a close proximity of said separating medium so that said particles are attracted to said electrostatic charges on said pyroelectric material and removed from said fluid stream.
Claim 2
Dependent Claim 132 words
A process for removing charged and non-charged particles from a fluid flow by attracting said particles to a separator device wherein said device comprises a separating medium formed of a poled, temperature sensitive pyroelectric material having a first surface and a second surface wherein said pyroelectric material produces electrostatic charges on said surfaces when its ambient temperature is varied, the charges produced on the first surface of said pyroelectric material being opposite in polarity to the charges produced on the second surface thereof, which process comprises the steps of: (a) varying the ambient temperature of said separating medium; and (b) passing the fluid flow within a close proximity of said separating medium so that said particles are attracted to said electrostatic charges on said pyroelectric material and removed from said fluid stream.
Claim 3
Dependent Claim 16 words
A process according to claim 1 wherein said pyroelectric material is formed from a polymeric material.
Claim 4
Dependent Claim 15 words
A process according to claim 1 wherein said pyroelectric material is formed from polyvinylidene fluoride.
Claim 5
Dependent Claim 44 words
A process according to claim 1 wherein said particle separator device further comprises a belt including said pyroelectric material, two rotatable shafts about which the belt is disposed, and at least one means of varying the temperature of said pyroelectric material of said belt.
Claim 6
Dependent Claim 148 words
A process for removing charged and non-charged particles from a fluid flow by attracting said particles to a separator device wherein said device comprises a separating medium formed of a poled, temperature sensitive pyroelectric material having a first surface and a second surface wherein said pyroelectric material produces electrostatic charges on said surfaces when its ambient temperature is varied, the charges produced on the first surface of said pyroelectric material being opposite in polarity to the charges produced on the second surface thereof, which process comprises the steps of: (a) varying the ambient temperature of said separating medium; (b) neutralizing the electrostatic charges produced on said first and second surfaces of the separating medium; and (c) passing the fluid flow within a close proximity of said separating medium so that said particles are attracted to said electrostatic charges on said pyroelectric material and removed from said fluid stream.
Claim 7
Dependent Claim 148 words
A process for removing charged and non-charged particles from a fluid flow by attracting said particles to a separator device wherein said device comprises a separating medium formed of a poled, temperature sensitive pyroelectric material having a first surface and a second surface wherein said pyroelectric material produces electrostatic charges on said surfaces when its ambient temperature is varied, the charges produced on the first surface of said pyroelectric material being opposite in polarity to the charges produced on the second surface thereof, which process comprises the steps of: (a) varying the ambient temperature of said separating medium; (b) neutralizing the electrostatic charges produced on said first and second surfaces of the separating medium; and (c) passing the fluid flow within a close proximity of said separating medium so that said particles are attracted to said electrostatic charges on said pyroelectric material and removed from said fluid stream.
Claim 8
Dependent Claim 79 words
A process according to claim 5 wherein said separator device further comprises a belt including said pyroelectric material wherein said pyroelectric material has a conductive layer applied to said first surface thereof and maintained at ground potential, a device for eliminating static electricity from portions of said second surface of said belt exposed thereto, two rotatable shafts about which the belt is disposed, and at least one means of varying the temperature of said pyroelectric material of said belt.

References Cited (Backward Citations)

US2067822A Cited
US2535697A Cited
US2724457A Cited
US3067078A Cited
US3375638A Cited
US3487610A Cited
US3701236A Cited
US3769096A Cited
US3877308A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1980-07-11 1981-01-10 1981-07-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-07-11 1985-01-10 1985-07-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-07-11 1989-01-10 1989-07-12 $7700.00 Window Closed / Lapsed

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