Ice modification removal and prevention

• US 20040149734A1
• Filed: 02/23/2004
• Published: 08/05/2004
• Est. Priority Date: 06/15/1998
• Status: Active Grant

• Current Assignee: Dartmouth College
• Original Assignee: Dartmouth College
• Inventors: Sullivan, Charles, Deresh, Lev, Petrenko, Victor
• Granted Patent: US 7,883,609 B2
• Time in Patent Office: Days
• US Class Current: 219/538
• CPC Class Codes: B60S 1/026 using electrical means
• CPC Class Codes: B60S 1/3805 electrically
• CPC Class Codes: B64D 15/12 by electric heating electric heating elements in general H05B
• CPC Class Codes: H05B 2214/02 Heaters specially designed for de-icing or protection against icing
• 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

An alternating electric field is applied to ice (530) to generate a resistive AC having a frequency greater than 1000 Hz in interfacial ice at interface (554). A first electrode (510) and a second electrode (514) proximate to the interface are separated by an electrical insulator (512). An AC power source (520) provides a voltage of about 10 to 500 volts across the electrodes to create the alternating electric field. A portion of the capacitive AC associated with the alternating electric field is present in the interfacial ice as conductivity (resistive) AC, which causes dielectric loss heating in the interfacial ice.

Claims

1. A system for melting interfacial ice 132, comprising:

a first electrode 110, 412, 510, 610, 710, 810

a second electrode 114, 414, 514, 614, 714, 814, the first electrode and the second electrode defining an interelectrode space 116 between the first electrode and the second electrode, the first electrode and the second electrode defining an interelectrode distance that separates the first electrode and the second electrode;

an AC power source 120, 520, 974 for providing an AC voltage across the first and second electrodes having a frequency greater than 100 Hz.

2. A system as in claim 1, wherein the AC power source provides an AC voltage in a range of about from 10 volts to 500 volts.

3. A system as in claim 1, further comprising an electrical insulator 112, 512, 712, 812, 813, 972 located in the interelectrode space.

4. A system as in claim 3, wherein the insulator comprises a nonconductive rubber windshield wiper blade 712, 813.

5. A system as in claim 1, wherein the interfacial ice 132 is located in the interelectrode space 116.

6. A system as in claim 1, wherein the interelectrode distance has a value in a range of about from 50 μ

m to 500 μ

m.

7. A system as in claim 1, wherein the interelectrode distance has a value less than 50 μ

m.

8. A system as in claim 1, wherein the interelectrode distance has a value greater than 500 μ

m.

9. A system as in claim 1, wherein the first electrode comprises a layer of conductive glass 110, 510.

10. A system as in claim 1, wherein the second electrode 114 comprises a layer of conductive glass.

11. A system as in claim 1, wherein the first electrode 110 comprises a transparent conductive metal oxide 304.

12. A system as in claim 1, wherein the first electrode comprises a conductive grid.

13. A system as in claim 1, wherein the second electrode comprises a conductive grid 304.

14. A system as in claim 1, wherein the first and second electrodes 412, 414, 960 are interdigitated.

15. A system as in claim 1, wherein the second electrode comprises a conductive rubber windshield wiper blade 514.

16. A method for melting interfacial ice 132 at an ice interface 134, 554, 758, 858, 978 comprising a step of:

applying an alternating electric field proximate to the ice interface 134, 554, 758, 858, 978 for generating a resistive AC in the interfacial ice.

17. A method as in claim 16, wherein the step of applying an alternating electric field includes:

applying an alternating electric field having a frequency greater than 100 Hz.

18. A method as in claim 16 wherein the step of applying an alternating electric field includes:

applying an AC voltage having a frequency greater than 100 Hz across a first electrode 110, 412, 510, 610, 710, 810 and a second electrode 114, 414, 514, 614, 714, 814 separated from each other by an interelectrode distance.

19. A method as in claim 18 wherein applying an AC voltage includes applying a voltage in a range of about from 10 volts to 500 volts.

20. A system for melting ice 2334, 2532, 2634, 2832 on a freezer package 2322, 2324, 2522, 2526, 2724, 2820, comprising:

a first electrode 2302, 2502, 2702, 2802;

a second electrode 2304, 2504, 2704, 2804, the first electrode and the second electrode defining an interelectrode space 2306, 2506, 2706, 2806 between the first electrode and the second electrode for accommodating the freezer package; and

an AC power source 2310, 2510, 2710, 2810 for providing an AC voltage across the first and second electrodes with a frequency not less than about 1000 Hz.

21. A system as in claim 20, wherein the AC voltage has a frequency in a range of about from 10 kHz to 30 kHz.

22. A system as in claim 20, wherein the AC voltage has an amplitude in a range of about from 10 V to 10 kV.

23. A system as in claim 20, further comprising:

a freezer package 2322, 2324, 2522, 2526, 2724, 2820 located in the interelectrode space 2306, 2506, 2706, 2806, the freezer package including a freezer package wall 2362, 2364, 2542, 2544, 2546, 2662, 2664, 2821 with an outer dielectric film 2363, 2366, 2663, 2666 and a continuous inner conductive layer 2364, 2367, 2665, 2667 contiguous to the outer dielectric film.

24. A system as in claim 23, wherein the freezer package wall 2542 includes a first portion 2552 proximate to the first electrode 2502 so that the AC voltage generates an alternating electric field between the first electrode 2502 and the first portion 2552 strong enough to melt interfacial ice.

25. A system as in claim 24, wherein the AC voltage heats the contents of the freezer package less than one calorie per gram of contents.

26. A system as in claim 24, further comprising:

a plurality of freezer packages arranged in a stack 2320, 2520, 2720, 2722 including a first freezer package 2322, 2522, 2724, 2726 proximate to the first electrode 2302, 2502, 2702 and a last freezer package 2328, 2526, 2725, 2727 proximate to the second electrode 2304, 2504, 2704, each of the plurality of freezer packages including an outer dielectric film and a continuous inner conductive layer contiguous to the outer dielectric film.

27. A system as in claim 23, wherein a freezer package contains food.

28. A system as in claim 23, wherein a freezer package contains biological tissue.

29. A freezer system 2700 for melting ice in a freezer, comprising:

a freezer including a housing 2701;

a first movable electrode 2702;

a second electrode 2704, the first movable electrode 2702 movable for forming an interelectrode space 2706 to accommodate a freezer package between the first movable electrode and the second electrode; and

an AC power source 2710 for providing an AC voltage across the first and second electrodes with a frequency not less than about 1000 Hz.

30. A system as in claim 29, wherein the second electrode 2704 is a movable electrode.

31. A system 2300 for melting ice, comprising:

a first electrode 2302;

a second electrode 2304, the first electrode and the second electrode defining an interelectrode space 2306 between the first electrode and the second electrode;

a conductive layer 2364 located in the interelectrode space and proximate to the ice, the conductive layer being electrically insulated from the first and second electrodes and from ice;

an AC power source 2310 for providing an AC voltage across the first and second electrodes with a frequency not less than about 1000 Hz.

32. A system as in claim 31, further comprising an outer dielectric film 2363 that electrically insulates the conductive layer from the first and second electrodes and from ice.

33. A system as in claim 31, wherein the AC voltage has a frequency in a range of about from 10 kHz to 30 kHz.

34. A system as in claim 31, wherein the AC voltage has an amplitude in a range of about from 10 V to 10 kV.

35. A method for melting ice on a freezer package 2322, comprising:

generating a high-frequency alternating electric field in the ice.

36. A method as in claim 35, wherein the high-frequency alternating electric field heats the contents of the freezer package less than one calorie per gram of contents.

37. A method as in claim 35, wherein generating a high-frequency alternating electric field in the ice includes applying an AC voltage with a frequency not less than about 1000 Hz across a first electrode 2302 and a second electrode 2304, the freezer package being located in an interelectrode space 2306 between the first electrode 2302 and the second electrode 304.

38. A method as in claim 37, wherein generating the high-frequency alternating electric field in the ice includes generating a conductivity AC in an inner conductive layer 2364 of a plurality of freezer packages arranged in a stack 2320, a first freezer package 2322 of the stack located proximate to the first electrode 2302, and a last freezer package 2328 of the stack located proximate to the second electrode 2304.

39. A method for melting ice, comprising:

generating a high-frequency alternating electric field in interfacial ice 2371.

40. A method as in claim 39, wherein the high-frequency alternating electric field heats bulk ice 2370 less than one calorie per gram of bulk ice.

41. A method as in claim 39, wherein generating the high-frequency alternating electric field in the ice includes applying an AC voltage with a frequency not less than about 1000 Hz across a first electrode 2302 and a second electrode 2304, thereby generating a conductivity AC in an inner conductive layer 2364, whereby the inner conductive layer is electrically insulated from the ice 2370, 2371 and the first and second electrodes 2302, 2304, and the interfacial ice 2371, the bulk ice 2370, and the inner conductive layer 2364 are located in an interelectrode space 2306 between the first and second electrodes.

42. A method as in claim 41 wherein the inner conductive layer 2364 is contiguous to an outer dielectric film 2363, and the outer dielectric film is located proximate to the first electrode and between the first electrode and the inner conductive layer.

43. A system of melting and preventing ice using a high-frequency electric field, comprising:

a first electrode;

a second electrode, the first electrode and the second electrode separated by an interelectrode distance in a range of about from 100 μ

m to 2 cm;

an interelectrode space defined by the first electrode and the second electrode and located between the first electrode and the second electrode;

a power source for providing an AC voltage across the first electrode and the second electrode with a frequency not less than 100 Hz.

44. A system as in claim 43, further comprising a plurality of first electrodes and a plurality of second electrodes, wherein the first electrodes alternate with the second electrodes, and wherein the interelectrode distance between adjacent first and second electrodes is in a range of about from 100 μ

m to 2 cm.

45. A system as in claim 44, wherein the first electrodes and the second electrodes are interdigitated.

46. A system as in claim 44, wherein the first and second electrodes are disposed on a surface of a solid object.

47. A system as in claim 46, wherein the solid object is selected from the group consisting of:

a cooling coil, a heat exchanger, an interior of a freezer, an external surface of an aircraft, an external surface of a ship, and a transportation surface.

48. A system as in claim 44, wherein the first electrodes and the second electrodes include heat exchanger fins.

49. A system as in claim 48, wherein each side surface of first electrode fins and second electrode fins has a surface area in a range of about from 1 cm² to 100 cm².

50. A system as in claim 44, wherein the first electrodes are physically connected to a cooling coil and are electrically connected to ground, and the second electrodes are electrically connected to the AC power source.

51. A system as in claim 44, wherein the AC power source provides a voltage in a range of about 250 volts (rms) to 2.5 kV (rms).

52. A system as in claim 44, wherein the AC power source generates an alternating electric field in a plurality of interelectrode spaces having a field strength in a range of about from 100 V/cm to 100 kV/cm.

53. A system as in claim 43, wherein the AC power source provides a voltage having a frequency in a range of about from 100 Hz to 100 MHz.

54. A system as in claim 43, wherein the AC power source provides power in a range of about from 1 W/m² to 50 kW/m² of protected surface area.

55. A system melting and preventing ice using a high-frequency electric field, comprising:

an electrode grid having a plurality of first electrode wires and a plurality of second electrode wires;

the first electrode wires and the second electrode wires crossing each other at a plurality of intersection nodes;

the first electrode wires substantially parallel to each other and located in a grid plane so that adjacent first electrode wires are separated by a first grid spacing in a range of about from 0.05 mm to 20 mm;

the second electrode wires substantially parallel to each other and located in the grid plane so that adjacent second electrode wires are separated by a second grid spacing in a range of about from 0.05 mm to 20 mm;

a first electrode wire and a second electrode wire defining an interelectrode space at a plurality of intersection nodes;

an electrical insulator located in the interelectrode space at a plurality of intersection nodes;

an AC power source for providing an AC voltage between the first electrode wires and the second electrode wires.

56. A system as in claim 55, wherein the first electrode wires and second electrode wires are coated with an insulating layer that separates the wires electrically.

57. A system as in claim 56, wherein the first electrode wires and second electrode wires contain aluminum and the insulating layer comprises anodized aluminum formed from the aluminum.

58. A system as in claim 55, wherein the AC power source provides a voltage in a range of about 250 volts (rms) to 2.5 kV (rms).

59. A system as in claim 55, wherein the AC power source provides power in a range of about from 1 W/m² to 50 kW/m² of protected surface area

60. A system as in claim 55, wherein the AC power source generates an alternating electric field having a field strength in a range of about from 100 V/cm to 100 kV/cm.

61. A system as in claim 55, wherein the AC power source provides a voltage having a frequency in a range of about from 100 Hz to 100 MHz.

62. A method of deicing using a high-frequency electric field, comprising a step of:

providing an alternating electric field, the alternating electric field having a field strength in a range of about from 100 V/cm to 100 kV/cm and a frequency not less than about 100 Hz.

63. A method as in claim 62, wherein the step of providing an alternating electric field comprises providing an AC voltage across a first electrode and a second electrode, the first electrode and the second electrode separated by an interelectrode distance in a range of about from 100 μ

m to 2 cm.

64. A method as in claim 62, further comprising steps of:

providing an AC voltage across adjacent electrodes of a plurality of first electrodes and a plurality of second electrodes, wherein the first electrodes alternate with the second electrodes, and wherein the interelectrode distance between adjacent first and second electrodes is in a range of about from 100 μ

m to 2 cm.

65. A method as in claim 62, wherein providing an AC voltage includes providing an AC voltage in a range of about 250 volts (rms) to 2.5 kV (rms).

66. A method as in claim 62, wherein providing an AC voltage includes providing a voltage having a frequency in a range of about from 100 Hz to 100 MHz.

67. A system 3100 for melting ice, comprising:

an electrical conductor 3104, 3204, 3302, 3414, 3504, 3554 for generating an AEF in response to an AC voltage;

a gas-filled layer 3110, 3210, 3320, 3410, 3510, 3560 proximate to the electrical conductor, the gas-filled layer containing a plasma-forming gas for forming a plasma in response to an AEF.

68. A system as in claim 67, further comprising:

a conductive layer 3220, 3224, 3412 located proximate to the electrical conductor.

69. A system as in claim 68, wherein the gas-filled layer 3110, 3210, 3320, 3410, 3510, 3566 is located between the electrical conductor and the conductive layer.

70. A system as in claim 69, wherein the conductive layer 3220, 3224 comprises ice.

71. A system as in claim 67, wherein the electrical conductor 3104, 3204, 3302, 3414, 3504, 3554 is a main conductor of a power transmission line.

72. A system as in claim 67, further comprising:

an AC power source 3101 for applying an AC voltage to the electrical conductor 3104, 3204, 3302, 3414, 3504, 3554.

73. A system as in claim 67, further comprising:

an AC voltage in the electrical conductor that generates an AEF, which AEF causes electric breakdown in the gas-filled layer 3110, 3210, 3320, 3410, 3510, 3560.

74. A system as in claim 73, wherein the AC voltage has a frequency in a range of about from 50 Hz to 1 MHz.

75. A system as in claim 73, wherein the AC voltage has a voltage in a range of about from 10 kV to 1300 kV.

76. A system as in claim 67, wherein the gas-filled layer 3110, 3210, 3320, 3410, 3510, 3560 comprises a gas selected from the group consisting of air, nitrogen and argon.

77. A system as in claim 67, wherein the gas-filled layer 3110, 3210, 3320, 3410, 3510, 3560 has a thickness in a range of about from 0.5 to 10 mm.

78. A system as in claim 67, further comprising an outer shell 3106, 3206, 3314, 3412, 3556, wherein the gas-filled layer 3110, 3210, 3320, 3410, 3510, 3560 is disposed between the electrical conductor and the outer shell.

79. A system as in claim 78, wherein the outer shell 3106, 3206, 3312, 3556 is electrically nonconductive.

80. A system as in claim 78, wherein the outer shell 3412, 3556 is electrically conductive.

81. A system as in claim 80, further comprising a switch for electrically shorting the electrical conductor and the conductive outer shell.

82. A system as in claim 67, wherein the gas-filled layer 3510, 3560 comprises gas-containing balls 3502, 3552.

83. A system as in claim 67, further comprising a flexible band 3310 that contains the gas-filled layer 3320.

84. A system for generating heat, comprising:

an electrical conductor 3104, 3204, 3302, 3414, 3504, 3554 for generating an AEF in response to an AC voltage;

a gas-filled layer 3110, 3210, 3320, 3410, 3510, 3560 proximate to the electrical conductor, the gas-filled layer 3110, 3210, 3320, 3410, 3510, 3560 containing a plasma-forming gas for forming a plasma in response to an AEF;

an AC power source 3101 for applying an AC voltage to the electrical conductor.

85. A system as in claim 84, further comprising:

a conductive layer 3220, 3224,3412 located proximate to the electrical conductor, wherein the gas-filled layer 3110, 3210, 3320, 3410, 3510, 3560 is located between the electrical conductor and the conductive layer.

86. A system as in claim 84, wherein the AC power source 3101 provides an AC voltage for generating an AEF having a strength in a range of about from 1 to 100 kV/cm.

87. A method for melting ice, comprising a step of:

generating an AEF in a gas-filled layer 3110, 3210, 3320, 3410, 3510, 3560 proximate to the ice for causing electric breakdown of gas and the formation of plasma in the gas-filled layer 3110, 3210, 3320, 3410, 3510, 3560.

88. A method as in claim 87, wherein the step of generating an AEF includes generating an AEF having a strength in a range of about from 1 to 100 kV/cm.

89. A method as in claim 87, wherein the step of generating an AEF includes applying an AC voltage to an electrical conductor 3104, 3204, 3302, 3414, 3504, 3554.

90. A method as in claim 89, wherein applying an AC voltage to the electrical conductor includes applying a voltage in a range of about from 10 kV to 1300 kV.

91. A system for de-icing a surface of a cableway system component, comprising:

an electrical conductor 4108 proximate to the surface 4107;

an AC power source 4102 for providing a high-frequency AC voltage in the electrical conductor that generates a high-frequency alternating electric field 4113 at the surface sufficient to melt ice 4110 at the surface.

92. A system as in claim 91, wherein the cableway system component 4106 functions as an electrical sink for the alternating electric field.

93. A system as in claim 92, wherein the cableway system component is connected to electrical ground 4130.

94. A system as in claim 91, wherein the electrical conductor 4108 is disposed at a distance of about from 0 to 30 cm from the cableway system component 4106.

95. A system as in claim 91, further comprising an electrical sink 4809, the electrical sink located proximate to the electrical conductor 4807 to increase the strength of the alternating electric field at the surface 4836.

96. A system as in claim 95, wherein the surface 4107, 4605, 4836 is disposed between the electrical conductor and the electrical sink.

97. A system as in claim 95, wherein the electrical conductor is disposed at a distance of about from 0 to 30 cm from the electrical sink.

98. A system as in claim 91, wherein the cableway system component 4908 is electrically conductive and is connected to the AC power source, and the electrical conductor 4906 is connected to the AC power source, so that the AC power source energizes cableway system component 4908 and electrical conductor 4906 at the same AC potential but 180 degrees out of phase from each other.

99. A system as in claim 91, wherein the AC power source 4120 provides high-frequency AC voltage with a frequency in a range of about from 60 kHz to 100 kHz.

100. A system as in claim 91, wherein the AC power source 4120 provides high-frequency AC voltage with a voltage in a range of about from 3 kV to 15 kV.

101. A system as in claim 91, wherein the cableway system component is a cableway 4106.

102. A system as in claim 91, wherein the cableway system component is a cableway system tower 4710.

103. A system as in claim 91, wherein the electrical conductor 4607, 4906 is integral with the cableway system component 4607, 4940.

104. A system for melting ice, comprising:

a first electrical conductor 4108 disposed at a distance of about from 0 to 30 cm from the ice 4110;

an AC power source 4120 for providing a high-frequency AC voltage in the first electrical conductor 4108 so that the AC voltage generates a high-frequency alternating electric field 4113 in the ice.

105. A system as in claim 104, further comprising an electrical sink 4609, the electrical sink disposed at a distance of about from 0 to 30 cm from the first electrical conductor 4607 to increase the strength of the alternating electric field 4613.

106. A system as in claim 105, wherein the ice 4610, 4612 is disposed between the first electrical conductor 4607 and the electrical sink 4609.

107. A system as in claim 105, wherein the ice 4612 covers a surface of an object 4609, 4710 being deiced, and the electrical sink is integral with the object 4609, 4710.

108. A system as in claim 104, wherein the ice 610, 4950 covers a surface 4605, 4941 of an object being deiced, and the first electrical conductor 4607, 4906 is integral with the object 4607, 4940.

109. A system as in claim 104, further comprising a second electrical conductor 4906 connected to the AC power source 4920, wherein the first electrical conductor 4908 is connected to the AC power source, so that the AC power source energizes the first electrical conductor and the second electrical conductor at the same AC potential but 180 degrees out of phase from each other.

110. A system as in claim 104, wherein the AC power source 4120 provides high-frequency AC voltage with a voltage in a range of about from 3 kV to 15 kV.

111. A method for de-icing a surface 4107 of a cableway system component 4106, comprising a step of:

applying a high-frequency AC voltage to an electrical conductor 4108 that is located proximate to the surface 4107, to generate a high-frequency alternating electric field that melts ice 4110 at the surface 4107.

112. A method as in claim 111, wherein the step of applying high-frequency AC voltage includes flowing AC with a frequency in a range of about from 60 kHz to 100 kHz.

113. A method as in claim 111, wherein the step of applying high-frequency AC voltage includes applying AC voltage with a voltage in a range of about from 3 to 15 kV.

114. A method as in claim 111, further comprising a step of connecting the cableway system component to electrical ground 4130.

115. A method as in claim 111, further comprising a step of providing an electrical sink 4609, 4809, wherein the surface 4605, 4836 is located between the electrical conductor 4607, 4807 and the electrical sink.

116. A method for melting ice, comprising a step of:

applying a high-frequency AC voltage to a first electrical conductor 4108 that is located at a distance of about from 0 to 30 cm from the ice 4110, to generate a high-frequency alternating electric field 4113 that melts the ice 4110.

117. A system for de-icing a cableway, comprising:

a cableway 5102, 5302, 5402, 5502, 5602; and

a power source 5104, 5304, 5425, 5404, 5607 electrically connected to the cableway for heating the cableway.

118. A system as in claim 117, wherein the power source provides AC power to the cableway.

119. A system as in claim 117, wherein the power source provides DC power to the cableway.

120. A system as in claim 117, further comprising a transformer 5570, 5572, 5574 connected to the power source and the cableway, whereby the power source provides power having a high voltage, and the transformer is capable of stepping down the high voltage to a low voltage.

121. A system as in claim 117, wherein the cableway includes a cable span 5116, 5342, said cable span having a first end 5140, 5142 and a second end 5141, 5143, and said cable span being separately connected to a power source.

122. A system as in claim 117, further comprising:

a circuit connection 5113, 5310, 5415, 5612; and

a plurality of cable spans, each cable span having a first end and a second end;

wherein the first ends of the cable spans are electrically connected through the circuit connection to a power terminal of a power source.

123. A system as in claim 122, wherein the circuit connection is switchably connectable to ground.

124. A system as in claim 122, wherein the second ends of the cable spans are electrically connected to ground.

125. A system as in claim 122, further comprising:

a plurality of cable spans, each cable span having a first end and a second end;

a first power bus connected to a first terminal of a power source; and

a second power bus;

wherein the first ends of the plurality of spans are electrically connected to the first power bus, and the second ends of the plurality of spans are electrically connected to the second power bus.

126. A system as in claim 125, wherein the second power bus is connected to electrical ground.

127. A system as in claim 117, further comprising a first end station connected to electrical ground, and a second end station connected to electrical ground, wherein the cableway is connected to electrical ground at the first and second end stations.

128. A system as in claim 117, wherein the cableway includes:

a first cable segment 5360, 5560 containing at least a first cable span 5340, 5540; and

a second cable segment 5362, 5562 containing at least a second cable span 5344, 5544, the first cable segment connected to a power source, and the second cable segment connected to a power source separately from the first cable segment.

129. A system as in claim 128, wherein the first cable segment is switchably connected to a power source separately from the second cable segment.

130. A system as in claim 128, further comprising a first transformer 5570 and a second transformer 5572, and wherein the first transformer is electrically connected to a power source and the first cable segment 5560, and the second transformer is electrically connected to a power source and the second cable segment 5562.

131. A system as in claim 117, further comprising a plurality of power sources 5425, 5445, wherein the cableway includes:

a first cable segment containing at least a first cable span, and a second cable segment containing at least a second cable span, the first cable segment is connected to a first power source in a first circuit, and the second cable segment is connected to a second power source in a second circuit

132. A system for de-icing an elongated conductor, comprising:

an elongated conductor 5502, 5602; and

a power source 5504, 5607 electrically connected to the elongated conductor;

wherein the elongated conductor includes a conductor span 5540, 5641, said conductor span having a first end 5622 and a second end 5623, and said conductor span being separately connected to a power source.

133. A system as in claim 132, wherein the power source provides AC power to the elongated conductor.

134. A system as in claim 132, wherein the power source provides DC power to the elongated conductor.

135. A system as in claim 132, further comprising a transformer 5572 connected to the power source and the elongated conductor, whereby the power source provides power having a high voltage, and the transformer is capable of stepping down the high voltage to a low voltage.

136. A system as in claim 132, further comprising:

a circuit connection 5512, 5612; and

a plurality of conductor spans 5641, 5642, each conductor span having a first end and a second end;

wherein the first ends of the conductor spans are electrically connected through the circuit connection to a first terminal of a power source.

137. A system as in claim 136, wherein the circuit connection is switchably connectable to ground.

138. A system as in claim 132, further comprising:

a plurality of conductor spans, each conductor span having a first end and a second end;

a first power bus 5520, 5608 connected to a first terminal of the power source; and

a second power bus 5522, 5609;

wherein the first end of a plurality of conductor spans is electrically connected to the first power bus, and the second end of the plurality of conductor spans is electrically connected to the second power bus.

139. A system as in claim 138, wherein the second power bus is connected to electrical ground.

140. A system as in claim 132, wherein the elongated conductor includes:

a first conductor segment 5560, 5630 containing at least a first conductor span; and

a second conductor segment 5562, 5640 containing at least a second conductor span, the first conductor segment connected to a power source, and the second conductor segment connected to a power source separately from the first conductor segment.

141. A system as in claim 140, wherein the first conductor segment is switchably connected to a power source separately from the second conductor segment.

142. A system as in claim 141, further comprising a first transformer 5570 and a second transformer 5572,

and wherein the first transformer is electrically connected to a power source and the first conductor segment, and the second transformer is electrically connected to a power source and the second conductor segment

143. A system as in claim 142, wherein the first transformer is switchably connected to a power source separately from the second transformer.

144. A system as in claim 132, further comprising:

a plurality of power sources 5425, 5445,

wherein the elongated conductor includes a first conductor segment and a second conductor segment 5430, the first conductor segment is connected to a first power source 5425 in a first circuit, and the second conductor segment is connected to a second power source 5445 in a second circuit.

145. A method for de-icing a cableway, comprising a step of:

applying electric power to the cableway for heating the cableway.

146. A method as in claim 145, wherein applying electric power includes separately applying electric power to a cable span.

147. A method as in claim 146, wherein applying electric power includes applying electric power to at least one cable span, and not applying power to at least one cable span.

148. A method as in claim 145, wherein applying electric power includes separately applying electric power to a cable segment.

149. A method as in claim 148, wherein applying electric power includes applying electric power to at least one cable segment, and not applying power to at least one cable segment.

150. A method as in claim 148, wherein applying electric power includes applying electric power having a voltage in a range of about from 10 to 20 volts to a cable segment.

151. A method as in claim 145, wherein applying electric power includes applying about 5 to 100 watts per meter of cableway.

152. A method as in claim 145, wherein the cableway has a plurality of spans, and further comprising steps of:

electrically connecting the first end of a plurality of spans to a first terminal of a power source; and

applying electric power separately to the plurality of connected spans.

153. A method as in claim 152, further comprising:

electrically connecting the second end of a plurality of spans to electrical ground.

154. A method as in claim 145, further comprising:

applying power to a first transformer that is electrically connected to the cableway, such that the first transformer reduces the voltage and increases the current of the power.

155. A method as in claim 154, further comprising:

applying power to the first transformer and a second transformer, the first transformer connected to a first cable segment containing at least a first cable span, the second transformer connected to a second cable segment containing at least a second cable span.

156. A method as in claim 145, wherein applying electric power comprises applying power from the first power source to a first cable segment, and applying power from a second power source to a second cable segment.

157. A method for de-icing an elongated conductor, comprising steps of:

separately connecting a conductor span to a power source; and

applying electric power to the connected conductor span.

158. A method as in claim 157, wherein applying electric power includes applying electric power simultaneously and separately to a plurality of conductor segments.

159. A method as in claim 157, wherein applying electric power includes separately applying electric power to at least one conductor segment, and not applying power to at least one conductor segment.

160. A method as in claim 157, further comprising:

applying power to a first transformer that is electrically connected to the elongated conductor, such that the first transformer reduces the voltage and increases the current of the power.

161. A method as in claim 160, further comprising:

applying power to the first transformer and a second transformer, the first transformer connected to a first conductor segment containing at least a first conductor span, the second transformer connected to a second conductor segment containing at least a second conductor span.

162. A method as in claim 157, further comprising:

applying power from a first power source to a first conductor segment, and applying power from a second power source to a second conductor segment.

163. A system for deicing a surface of a solid object, comprising:

a first electrode 6044, 6312, 6402, 6502, 6812 contiguous with the surface 6014, 6044, 6302, 6502, 6804;

a second electrode 6042, 6316, 6404, 6512, 6650, 6814, separated from the first electrode by an interelectrode distance, wherein the first and second electrodes cover the surface;

an interelectrode space 6318, 6408, 6520, 6820 between the first electrode and the second electrode; and

.

a power source 6018, 6048 for applying a voltage between the first electrode and the second electrode, wherein the power source is selected from the group consisting of a DC power source and a low-frequency AC power source.

164. A system as in claim 163, wherein the surface 6014, 6044, 6302, 6502, 6804 is a land-based transportation surface.

165. A system as in claim 163, wherein the interelectrode distance has a value in a range of from 0.5 to 10 mm.

166. A system as in claim 163, wherein the power source provides a voltage in a range of from 2 to 100 volts.

168. A system as in claim 163, wherein the surface 6804 is electrically nonconductive, the first electrode 6812 is a continuous layer of conductive material covering a first portion of the surface, the second electrode 6814 is a continuous layer of conductive material covering a second portion of the surface, and the interelectrode space 6820 covers a third portion of the surface between the first and second portions.

169. A system as in claim 168, wherein the conductive material is selected from the group consisting of metal sheets, conductive metal oxide, conductive concrete, conductive asphalt, conductive polymer, carbon, and conductive paint.

170. A system as in claim 163, wherein the surface 6302 is electrically nonconductive, the first electrode 6312 is a bottom electrode layer disposed on the surface, the second electrode 6316 is a porous top electrode layer located above the first electrode;

and further comprising a porous insulator 6314 disposed between the bottom first electrode and the porous top second electrode layer.

171. A system as in claim 170, wherein a stacked, laminate coating 6310 covers the surface 6312 and the laminate coating comprises a bottom electrode layer 6312, a porous insulator layer 6314, and a porous top electrode layer 6316.

172. A system as in claim 163, wherein a composite mesh coating 6400 covers the surface and the composite mesh coating comprises a plurality of first electrode wires 6402, a plurality of second electrode wires 6404, and a plurality of insulator fibers 6406, wherein the insulator fibers electrically insulate the first electrode wires from the second electrode wires.

173. A system as in claim 163, wherein the surface 6044, 6502 is conductive and serves as the first electrode.

174. A system as in claim 173, wherein the second electrode 6510 is a porous conductive layer located above the first electrode surface, and further comprising a porous insulator layer 6514 that electrically insulates the second electrode from the first electrode surface.

175. A system as in claim 173, wherein a mesh 6650 covers the first electrode surface 6502, and the mesh comprises conductive second electrode wires 6652 having a top and bottom, the bottom of the second electrode wires being coated with a coating of an electrical insulator.

176. A system as in claim 163, further comprising a DC power supply 6830 for providing a voltage to generate sparks at the electrodes.

177. A system as in claim 176, further comprising a spark plug 6832 connected to the DC power supply for generating sparks at the electrodes.

167. A system as claimed in 163, wherein the power source provides a current density in water at the electrodes in a range of from 0.1 to 10 mA/cm².

178. A method for deicing a surface of a solid object, comprising steps of:

applying a voltage between a first electrode 6044, 6312, 6402, 6502, 6812 and a second electrode 6042, 6316, 6404, 6512, 6650, 6814,

wherein the first electrode is contiguous with the surface 6014, 6044, 6302, 6502, 6804, an the first electrode and second electrode are separated by an interelectrode distance, and the first and second electrodes cover the surface and define an interelectrode space 6318, 6408, 6520, 6820 between the first electrode and the second electrode, and the voltage generates an electric current in water in the interelectrode space, and the voltage is selected from the group consisting of a DC voltage and low-frequency AC voltage.

179. A method as in claim 178, further comprising a step of generating a spark to ignite a mixture of hydrogen and oxygen gases.

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

a first electrode 7110, 7210, 7420 disposed on the surface 7104, 7204, 7404;

a second electrode 7120, 7220, 7422 proximate to the first electrode;

an interelectrode space 7118, 7426 separating the first and second electrodes; and

an AC power source 7120 connected to the first and second electrodes, the power source providing an AC voltage with sufficient power to prevent freezing of a liquid water layer 7119, 7462 in the interelectrode space.

181. A system as in claim 180, wherein the power source provides an AC voltage having a frequency in a range of from 15 Hz to 1 kHz.

182. A system as in claim 180, wherein the power source provides an AC voltage having a frequency in a range greater than 1 kHz.

183. A system as in claim 180, wherein the power source provides an AC voltage in a range of from 0.1 to 100 volts.

184. A system as in claim 180, wherein the power source provides a current density in a liquid water layer in the interelectrode space in a range of from 1 to 100 mA/cm².

185. A system as in claim 180, wherein the interelectrode space has a thickness not exceeding 3 mm.

186. A system as in claim 180, wherein the interelectrode space has a thickness not exceeding 500 μ

m.

187. A system as in claim 180, wherein the interelectrode space has a thickness in a range of from 5 nm to 100 μ

m.

188. A system as in claim 180, wherein the first electrode comprises a material selected from the group consisting of aluminum, copper, titanium, platinum, nickel, gold, mercury, palladium, carbon, SnO₂, InSnO₂, RuO₂ and IrO₂.

189. A system as in claim 180, wherein the second electrode comprises a material selected from the group consisting of aluminum, copper, titanium, platinum, nickel, gold, mercury, palladium, carbon, SnO₂, InSnO₂, RuO₂ and IrO₂.

190. A system as in claim 180, wherein the surface 7404 is electrically nonconductive, the first electrode 7420 is disposed on a first portion of the surface, a second electrode 7422 is disposed on a second portion of the surface, and a third portion 7426 of the surface is located between the first and second electrodes.

191. A system as in claim 180, wherein the second electrode 7120, 7220 covers the first electrode 7110, 7210, and the second electrode is exposed to water and is porous to water.

192. A system as in claim 191, wherein the second electrode is a mesh 7214 comprising metal mesh fibers.

193. A system as in claim 191, further comprising a porous insulator layer 7112, 7212 disposed between the first electrode and the second electrode, the porous insulator layer forming the interelectrode space and being porous to water.

194. A system as in claim 193, wherein the pore space occupies in a range of from 50 to 70 percent of the total volume.

195. A system as in claim 193, wherein the first electrode 7210 comprises aluminum and the porous insulator layer 7212 comprises aluminum oxide.

196. A system as in claim 180, wherein the first electrode is integral with the solid object.

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

a first electrode and 7110, 7210, 7420 disposed on the surface 7104, 7204, 7404;

a second electrode 7120, 7220, 7422 proximate to the first electrode;

an interelectrode space 7118, 7426 separating the first and second electrodes; and

a DC power source 7430 connected to the first and second electrodes for providing a DC voltage with sufficient power to prevent freezing of a liquid water layer 7119, 7462 in the interelectrode space.

198. A method for preventing ice formation in a liquid water layer, comprising:

flowing an electric current through the liquid water layer 7119, 7462.

199. A method as in claim 198, wherein flowing an electric current includes flowing a current with a current density in a range of from 1 to 100 mA/cm².

200. A method as in claim 198, wherein the step of flowing an electric current comprises flowing AC having a frequency greater than about 15 Hz.

201. A method as in claim 200, wherein flowing AC through the liquid water layer comprises steps of:

providing an AC voltage in an electrode having an interface with the liquid water layer. 7119, 7462.

202. A method as in claim 201, wherein the step of providing an AC voltage includes providing a voltage with a frequency in a range of from 15 Hz to 1 kHz.

203. A method as in claim 201, wherein the step of providing an AC voltage includes providing a voltage with an amplitude in a range of from 0.1 to 100 volts.

204. A method as in claim 203, wherein the step of providing an AC voltage includes providing a voltage with an amplitude in a range of from 5 to 25 volts.

205. A method as in claim 198, wherein the step of flowing an electric current comprises flowing DC with a current density in a range of from 1 to 100 mA/cm².

206. A system for increasing friction at a contact interface between a layer of ice 8104, 8404, 8550 and a solid object 8106, 8206, 8306, 8406, 8562, 8604, comprising:

a plurality of electrodes 8136, 8233, 8235, 8462, 8464, 8610, 8612 wherein the electrodes are located proximate to the contact interface 8110, 8410, 8510;

an AC power source 8120, 8320 electrically connected to the electrodes, wherein the power source provides a potential difference across the electrodes to generate an AC electric field at the contact interface.

207. A system as in claim 206, whereby the power source provides an AC electric field having a frequency not exceeding 1000 Hz.

208. A system as in claim 206, whereby the power source provides an AC electric field having a frequency not exceeding 100 Hz.

209. A system as in claim 206, wherein the electric field has a value in a range of from 100 V/cm to 10⁵ V/cm.

210. A system as in claim 206, wherein the electrodes are separated from each other by an interelectrode spacing 8236, 8458, 8620 not exceeding 4 mm.

211. A system as in claim 206, whereby the electrodes are separated from each other by an interelectrode spacing not exceeding 100 μ

m.

212. A system as in claim 206, whereby the electrodes are interdigitated.

213. A system as in claim 206, further comprising electrical insulation that insulates each of the electrodes.

214. A system as in claim 206, wherein the electrodes possess an electrical conductivity greater than 10⁻

10 S/cm.

215. A system as in claim 206, further comprising an additional impedance between the AC power source and the electrodes to limit AC at the electrodes.

216. A system as in claim 215, comprising a capacitor 8335 in series between the AC power source and the electrodes.

217. A system as in claim 206, further comprising a switching mechanism 8332, 8334 for electrically connecting the AC power source to electrodes proximate to the contact interface and for electrically disconnecting the AC power source from electrodes not proximate to the contact interface.

218. A system as in claim 206, further comprising dopants that impart electrical conductivity in the electrodes.

219. A system as in claim 206, wherein the layer of ice 8404 covers a paved surface and the solid object is a rubber tire 8106, 8206, 8306, 8406.

220. A system as in claim 219, wherein the rubber tire contains a plurality of electrodes 8233, 8235, 8452, 8454 and dopants to impart electrical conductivity in the electrodes.

221. A system as in claim 206, whereby the solid object is selected from the group consisting of:

a wheel of a rail vehicle;

a track of a tracked vehicle;

a snow ski;

a shoe sole.

222. A system as in claim 206, whereby the power source provides a voltage in a range of from 1 to 5000 volts.

223. A system as in claim 206, whereby the AC power source provides a voltage not exceeding 100 volts.

224. A method for increasing friction at a contact interface between a layer of ice 8104, 8404, 8550 and a solid object 8106, 8206, 8306, 8406, 8562, 8604, comprising steps of:

generating an AC electric field at the contact interface 8110, 8410, 8510.

225. A method as in claim 224 whereby the step of generating an AC electric field comprises generating an electric field having a frequency not exceeding 1000 Hz.

226. A method as in claim 224 whereby the AC electric field has a frequency not exceeding 100 Hz.

227. A method as in claim 224 comprising providing an electric field having a field strength in a range of from 100 V/cm to 10⁵ V/cm.

228. A method as in claim 224, further comprising:

providing an AC potential difference across a plurality of electrodes 8136, 8233, 8235, 8462, 8464, 8610, 8612 located proximate to the contact interface.

229. A method as in claim 228, wherein the step of providing an AC potential difference comprises providing a voltage in a range of from 1 to 5000 volts.

230. A method as in claim 228, further comprising switching the potential difference “

off”

in electrodes 8452, 8454 that are not proximate to the contact interface.

231. A system for increasing friction at a contact interface between a layer of ice and a solid object, comprising:

a plurality of electrodes 8136, 8233, 8235, 8462, 8464, 8610, 8612, wherein the electrodes are located proximate to the contact interface 8110, 8410, 8510;

a DC power source 8120 electrically connected to the electrodes, wherein the power source provides a DC voltage greater than 1000 volts across the electrodes to generate a DC electric field at the contact interface.

232. A method for increasing friction at a contact interface between a layer of ice and a solid object, comprising the step of:

generating an DC electric field at the contact interface, wherein the electric field has a value not less than 100 V/cm.

233. A method as in claim 232, wherein the step of generating the DC electric field includes:

providing a DC potential difference greater than 1000 volts across two electrodes located proximate to the contact interface.