US6726743B2
Expired / Lapsed
US
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Electrostatic deaeration method and apparatus
Assignee: 3M Innovative Properties Co
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Filing: 2002-06-18
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Granted: 2004-04-27
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Expires: 2022-06-18
Abstract
Abstract This disclosure relates to a method for deaerating a liquid layer such as a coating solution using electrostatic forces. A flow of charged particles is created above and moved towards a low conductivity liquid layer. The flow of charged particles causes localized thinning of the liquid layer which facilitates the removal of bubbles of entrained gas from the liquid by bringing those bubbles closer to the exposed surface of the liquid and rupturing them at that surface. This electrostatic deaeration technique is combined with other non-electrostatic liquid layer thinning techniques or degassing techniques to further facilitate removal of bubbles from the liquid in preparation of further processing of the liquid. The liquid layer may be stationary or flowing with respect to the application of charge particles.
Inventors
- 👤 John W. Louks
- 👤 Steven H. Gotz
- 👤 Luther E. Erickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:40
CPC Classifications
B; B01; B01D; B01D19/00; B01D19/0073; B01D19/0078; B01D19/0021; B01D19/0042; B01D19/0052; B01D19/0084
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
97 words
A method of deaerating a gas contained in a low conductivity liquid, comprising: providing a support surface; establishing a layer of liquid having a first lower surface contacting the support surface and a second exposed surface, the layer of liquid having bubbles of gas entrained therein and having a thickness; and causing localized thinning of the layer of liquid by providing a flow of charged particles above the layer of liquid and towards the support surface whereby the bubbles of gas entrained in the layer of liquid are moved closer to the second exposed surface and ruptured.
Claim 2
Independent Claim
97 words
A method of deaerating a gas contained in a low conductivity liquid, comprising: providing a support surface; establishing a layer of liquid having a first lower surface contacting the support surface and a second exposed surface, the layer of liquid having bubbles of gas entrained therein and having a thickness; and causing localized thinning of the layer of liquid by providing a flow of charged particles above the layer of liquid and towards the support surface whereby the bubbles of gas entrained in the layer of liquid are moved closer to the second exposed surface and ruptured.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein the causing step includes an additional step of inducing localized thinning of the layer of liquid which does not require providing a flow of charged particles.
Claim 4
Dependent Claim
38 words
The method of claim 1 wherein the flow of charged particles is provided above the layer of liquid at a charge station, and wherein there is relative longitudinal movement between the layer of liquid and the charge station.
Claim 5
Dependent Claim
20 words
The method of claim 3 , and further comprising: moving the layer of liquid relative to a stationary charge station.
Claim 6
Dependent Claim
14 words
The method of claim 4 wherein the moving step includes moving the support surface.
Claim 7
Dependent Claim
24 words
The method of claim 4 , and further comprising: statically mixing the layer of liquid upstream from the charge station, relative to liquid movement.
Claim 8
Dependent Claim
19 words
The method of claim 6 wherein the statically mixing step comprises: providing a microreplicated surface on the support surface.
Claim 9
Dependent Claim
30 words
The method of claim 4 and further comprising: providing a structure disposed within the layer of liquid, adjacent the charge station, to enhance local thinning of the layer of liquid.
Claim 10
Dependent Claim
14 words
The method of claim 8 wherein the structure is disposed on the support surface.
Claim 11
Dependent Claim
23 words
The method of claim 3 wherein the additional inducing step comprises: disposing a structure within the layer of liquid adjacent the charge station.
Claim 12
Dependent Claim
14 words
The method of claim 10 wherein the structure is disposed on the support surface.
Claim 13
Dependent Claim
12 words
The method of claim 11 wherein the structure comprises a microreplicated surface.
Claim 14
Dependent Claim
56 words
The method of claim 3 wherein the causing step includes an additional step of inducing thinning of the layer of liquid which does not require providing a flow of charged particles at an area that is at least one of: the charge station or prior to movement of the layer of liquid into the charge station.
Claim 15
Dependent Claim
24 words
The method of claim 13 wherein the additional inducing step comprises providing relative longitudinal movement between the layer of liquid and the support surface.
Claim 16
Dependent Claim
44 words
The method of claim 13 wherein the additional inducing step comprises transferring the layer of liquid from the support surface to a substrate surface having a higher longitudinal velocity than the support surface in order to extensionally stress and thin the layer of liquid.
Claim 17
Dependent Claim
65 words
The method of claim 3 wherein the support surface is on a support which has a first side, defined by the support surface, and a second side, wherein the support surface of the support is non-conductive, and further comprising: providing electrical charges on the second side of the support which have an opposite polarity to the flow of charged particles above the layer of liquid.
Claim 18
Dependent Claim
22 words
The method of claim 16 wherein the electrical charges are provided on the second side of the support upstream from charge station.
Claim 19
Dependent Claim
31 words
The method of claim 3 wherein the source of the charged particles is at least one of: a direct current source, an alternating current source, or a pulsed direct current source.
Claim 20
Dependent Claim
19 words
The method of claim 18 wherein the alternating current source cycles at from 1 to 10 cycles per second.
Claim 21
Dependent Claim
39 words
The method of claim 16 wherein the source of the charged particles is an alternating current source and the electrical charges on the second side of the support are phased to be an opposite polarity to the charged particles.
Claim 22
Dependent Claim
19 words
The method of claim 4 and further comprising: creating turbulence in the layer of liquid adjacent the charge station.
Claim 23
Dependent Claim
22 words
The method of claim 21 wherein the turbulence creating step includes at least one of: a static mixer or an electrostatic field.
Claim 24
Dependent Claim
45 words
The method of claim 1 wherein the causing step includes providing the flow of charged particles at a level sufficient to create vortices in the layer of liquid which urge the bubbles of gas entrained in the layer of liquid toward the second exposed surface.
Claim 25
Dependent Claim
65 words
The method of claim 1 wherein the support surface is on a support which has a first side, defined by the support surface, and a second side, wherein the support surface of the support is non-conductive, and further comprising: providing electrical charges on the second side of the support which have an opposite polarity to the flow of charged particles above the layer of liquid.
Claim 26
Dependent Claim
24 words
The method of claim 24 wherein the electrical charges on the second side of the support reside on the second side of the support.
Claim 27
Dependent Claim
14 words
The method of claim 1 wherein the liquid-bearing surface of the support is grounded.
Claim 28
Dependent Claim
11 words
The method of claim 1 wherein the support surface is conductive.
Claim 29
Dependent Claim
14 words
The method of claim 1 , and further comprising: acoustically exciting the support surface.
Claim 30
Dependent Claim
18 words
The method of claim 28 wherein the acoustically exciting step comprises exciting the support surface at ultrasonic frequencies.
Claim 31
Dependent Claim
29 words
The method of claim 1 wherein the causing step comprises: electrically energizing an electrode above the second exposed surface of the layer of liquid to generate the charged particles.
Claim 32
Dependent Claim
12 words
The method of claim 30 wherein the electrode is a corona wire.
Claim 33
Dependent Claim
30 words
The method of claim 1 wherein the causing step comprises: electrically energizing a plurality of electrodes above the exposed surface of the layer of liquid to generate the charged particles.
Claim 34
Dependent Claim
57 words
The method of claim 32 wherein there is relative longitudinal movement between the layer of liquid and the electrodes, and at least two charge stations are defined longitudinally along the layer of liquid by charged particles from the electrodes, and further comprising: statically mixing the layer of liquid between the two charge stations, relative to liquid movement.
Claim 35
Dependent Claim
49 words
The method of claim 1 wherein the causing step comprises: generating the charged particles by an ion generator remotely positioned relative to the layer of liquid; and transferring the charged particles from the ion generator to the second exposed surface of the layer of liquid through a fluid medium.
Claim 36
Dependent Claim
22 words
The method of claim 1 wherein there is an absence of relative motion between the layer of liquid and the support surface.
Claim 37
Dependent Claim
17 words
The method of claim 1 wherein the support surface is at an elevated potential relative to ground.
Claim 38
Dependent Claim
23 words
The method of claim 1 wherein the charged particles have a first polarity, and wherein the support surface has a second, opposite polarity.
Claim 39
Dependent Claim
18 words
The method of claim 1 and further comprising: degassing the layer of liquid, prior to the causing step.
Claim 40
Independent Claim
101 words
An apparatus for deaerating a gas contained in a low conductivity liquid, comprising: a support surface for supporting a layer of liquid which has a first lower surface contacting the support surface and a second, exposed surface, with the layer of liquid having bubbles of gas entrained therein and having a thickness; and means for causing localized thinning of the layer of liquid by providing a flow of charged particles above the layer of liquid and towards the support surface whereby the bubbles of gas entrained in the layer of liquid are moved closer to the second exposed surface and ruptured.
Claim 41
Independent Claim
101 words
An apparatus for deaerating a gas contained in a low conductivity liquid, comprising: a support surface for supporting a layer of liquid which has a first lower surface contacting the support surface and a second, exposed surface, with the layer of liquid having bubbles of gas entrained therein and having a thickness; and means for causing localized thinning of the layer of liquid by providing a flow of charged particles above the layer of liquid and towards the support surface whereby the bubbles of gas entrained in the layer of liquid are moved closer to the second exposed surface and ruptured.
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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) | 2007-04-27 | 2007-10-27 | 2008-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-04-27 | 2011-10-27 | 2012-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-04-27 | 2015-10-27 | 2016-04-27 | $7700.00 | Window Closed / Lapsed |