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

• US 7,227,110 B2
• Filed: 11/09/2004
• Issued: 06/05/2007
• Est. Priority Date: 06/15/1998
• Status: Expired due to Fees

• 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:
  US10/984,475
• Publication Number:
  US 20050167427A1
• Time in Patent Office: 938 Days
• Field of Search: 219/772, 219/770, 219/780, 219/497, 219/209, 219/644, 219/635, 310/321, 310/322, 310/323.21, 392311-312, 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, 405/128.6, 166/245, 166/248, 588/253
• US Class Current: 219/772
• 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 method for preventing ice formation in a liquid water layer by flowing an electric current through the liquid water layer, comprising:

providing a first electrode on a surface;

providing a second electrode proximate to the first electrode, thereby forming an interelectrode space between the first electrode and the second electrode, wherein the liquid water layer is disposed in the interelectrode space; and

applying electric power between the first and second electrodes, the power being sufficient to depress the freezing point of the liquid water layer in the interelectrode space,

wherein the freezing point is depressed from 1°

C. to 80°

C.

2. The method of claim 1, wherein the step of applying electric power causes a current density in the liquid water layer in the interelectrode space in a range of from 10 to 100 mA/cm².

3. 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 and being porous to water, the

second electrode and first electrode being separated by an interelectrode space; and

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

4. The system of claim 3, wherein the power source is capable of providing a current density in a liquid water layer in the interelectrode space in a range of from 1 to 100 mA/cm².