Prevention of ice formation by applying electric power to a liquid water layer

• US 6,847,024 B2
• Filed: 10/04/2001
• Issued: 01/25/2005
• Est. Priority Date: 06/15/1998
• Status: Expired due to Term

• Current Assignee: The Trustees of Dartmounth College (Dartmouth College)
• Original Assignee: The Trustees of Dartmounth College (Dartmouth College)
• Inventors: Petrenko, Victor F.
• Primary Examiner(s): Van, Quang T.
• Application Number:
  US09/970,555
• Publication Number:
  US 20020096515A1
• Time in Patent Office: 1,209 Days
• Field of Search: 219/770, 219/497, 219/209, 219/772, 219/780, 244/134.R, 244/134.D, 244/134.F, 244/138.R, 174/110.R, 174/102.R, 174/115, 174/128.1, 206/317, 206/589, 307/147, 392/311, 392/312, 405/128.6, 166/245, 166/248, 588/253
• US Class Current: 219/770
• CPC Class Codes: B60S 1/026 using electrical means
• CPC Class Codes: B60S 1/3805 electrically
• CPC Class Codes: B63J 99/00 Subject matter not provided for in other groups of this subclass
• CPC Class Codes: B64D 15/12 by electric heating electric heating elements in general H05B
• CPC Class Codes: B64D 15/163 using electro-impulsive devices
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: E01C 11/265 Embedded electrical heating elements in floors F24D13/00; Mounting thereof
• CPC Class Codes: E01D 19/00 Structural or constructional details of bridges
• CPC Class Codes: H05B 2203/006 using interdigitated electrodes
• CPC Class Codes: H05B 2203/009 Heaters using conductive material in contact with opposing surfaces of the resistive element or resistive layer
• CPC Class Codes: H05B 2203/016 Heaters using particular connecting means
• CPC Class Codes: H05B 2203/017 Manufacturing methods or apparatus for heaters
• CPC Class Codes: H05B 2214/02 Heaters specially designed for de-icing or protection against icing
• CPC Class Codes: H05B 3/347 woven fabrics
• CPC Class Codes: H05B 3/56 Heating cables
• CPC Class Codes: H05B 3/84 Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields
• CPC Class Codes: H05B 6/62 Apparatus for specific applications

Abstract

A first electrode is separated from a second electrode by an interelectrode space. The interelectrode space does not exceed 3 mm, and preferably does not exceed 100 μm. Liquid water fills the interelectrode space, thereby electrically connecting the first electrode and the second electrode. A power supply, preferably low-frequency AC, is connected to the first and second electrodes, generating a current through the water in the interelectrode space. The applied electric power prevents freezing of a thin liquid water layer in the interelectrode space, thereby preventing ice formation.

Claims

1. A system for preventing ice formation on a surface of a solid object, comprising:

a first electrode disposed on the surface;

a second electrode proximate to the first electrode;

an interelectrode space separating the first and second electrodes, wherein the interelectrode space has a thickness not exceeding 3 mm; and

an AC power source connected to the first and second electrodes, the power source capable of providing an AC voltage with sufficient power to prevent freezing of a liquid water layer in the interelectrode space.

2. A system as in claim 1, wherein the interelectrode space has a thickness not exceeding 500 μ

m.

3. A system as in claim 1, wherein the interelectrode space has a thickness in a range of from 5 nm to 100 μ

m.

4. A system for preventing ice formation on a surface of a solid object, comprising:

a first electrode disposed on the surface;

a second electrode covering the first electrode, the second electrode being exposed to water and being porous to water;

an interelectrode space separating the first and second electrodes; and

an AC power source connected to the first and second electrodes, the power source capable of providing an AC voltage with sufficient power to prevent freezing of a liquid water layer in the interelectrode space.

5. A system as in claim 4, wherein the second electrode is a mesh comprising metal mesh fibers.

6. A system as in claim 5 wherein the metal mesh fibers have a thickness in a range of from 1 to 100 μ

m.

7. A system as in claim 4, further comprising a porous insulator layer disposed between the first electrode and the second electrode, the porous insulator layer forming the interelectrode space and being porous to water.

8. A system as in claim 7, wherein the porous insulator layer has a total volume and a pore space, and the pore space occupies between 0 and 100 percent of the total volume.

9. A system as in claim 8, wherein the pore space occupies in a range of from 50 to 70 percent of the total volume.

10. A system as in claim 7, wherein the first electrode comprises aluminum and the porous insulator layer comprises aluminum oxide.

11. A system as in claim 10, wherein the porous insulator layer comprises anodized aluminum.