PULSE SYSTEMS AND METHODS FOR DETACHING ICE

US 20090199569A1
Filed: 06/22/2005
Published: 08/13/2009
Est. Priority Date: 06/22/2004
Status: Active Grant

First Claim

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1. An ice making system, comprising:

a cold plate;

a dielectric film, the dielectric film comprising varying thickness such that the ice is thinner where the dielectric film is thicker;

a thin meal foil cooled by the cold plate through the dielectric film, such that water adjacent the metal foil forms ice thereon;

a power supply; and

a switch operable to couple current from the power supply to the thin metal foil, to generate a heating pulse that melts an interfacial layer of the ice at the thin metal foil and release the ice.

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Abstract

A pulse system for detaching ice includes a power supply for applying a high-power heating pulse to the interface between ice and an object such as a cold plate of an ice making system, an ice-container, a heat-exchanger, a refrigerator surface or an airplane wing. Pulse heating may be generated within a metal foil or resistive film disposed upon an object to be deiced, or a capillary tube proximate the object to be deiced. An interfacial layer of ice is melted and the ice is released from the object. A force, for example gravity, pressure of vaporization or mechanical scraping, removes the ice from the object.

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68 Claims

1. An ice making system, comprising:
- a cold plate;
  
  a dielectric film, the dielectric film comprising varying thickness such that the ice is thinner where the dielectric film is thicker;
  
  a thin meal foil cooled by the cold plate through the dielectric film, such that water adjacent the metal foil forms ice thereon;
  
  a power supply; and
  
  a switch operable to couple current from the power supply to the thin metal foil, to generate a heating pulse that melts an interfacial layer of the ice at the thin metal foil and release the ice.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16)
- - 2. The system of claim 1, the power supply comprising AC power or DC power supply.
  - 3. The system of claim 1, the power supply comprising a battery or a capacitor or an ultracapacitor.
  - 4. The system of claim 1, the switch comprising a power-MOSPET, IGBT, thyristor, mechanical switch, an electromagnetic switch, or combination Thereof.
  - 5. The system of claim 1, wherein applied voltage and current of the heating pulse provides sufficient density of heating power in an approximate range of 1 kw/m²to 500 kw/m².
  - 6. The system of claim 5, the voltage being 2.5V to 1000V, depending on electrical resistance of the metal foil.
  - 7. The system of claim 1, the metal foil having a thickness of 0.5 μ
    - m to 1 mm.
  - 8. The system of claim 1, the metal foil comprising conductive paint, conductive polymer film, carbon-fiber composite material or carbon nanotube composite material.
  - 9. The system of claim 1, the dielectric film electrically isolating the metal foil from the cold plate and comprising one or more of ceramic, glass, rubber, polymer and composite materials.
  - 10. The system of claim 9, the dielectric film having thickness in a range of 10 μ
    - m to 2 mm.
  - 11. The system of claim 1, the switch operating such that the beating pulse has a duration from 1 ms to 30 s.
  - 12. The system of claim 1, wherein the metal foil forms one or more pockets for the ice.
  - 13. The system of claim 12, wherein ice released from the foil after the heating pulse comprises ice cubes.
  - 15. The system of claim 1, the varying thickness constructed and arranged such that the ice forms a shape.
  - 16. The system of claim 15, the shape being one of a semi-sphere, semi-cylinder, rectangular bar, star.

14.

17. An ice making system, comprising:
- a cold plate;
  
  a metal foil cooled by the cold plate, such that water adjacent the metal foil forms ice thereon;
  
  a pump for pumping air into or out of a space between the cold plate and the metal foil, wherein pumping in air separates the cold plate from the metal foil and wherein pumping air out removes air from the space and compresses the metal foil to the cold plate;
  
  a power supply; and
  
  a switch operable to couple current from the power supply to the metal foil, to generate a heating pulse that melts an interfacial layer of the ice at the metal foil and release the ice.
- View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
- - 19. The system of claim 17, the space being approximately 10 μ
    - m to 2 cm.
  - 20. The system of claim 17, the metal foil forming one or more pockets for the ice.
  - 21. The system of claim 17, the cold plate forming one or more grooves to shape ice grown onto the metal foil.
  - 22. The system of claim 17, wherein applied voltage and current of the heating pulse provides sufficient density of heating power in an approximate range of 1 kw/m²to 500 kw/m².
  - 23. The system of claim 17, the voltage being 2.5V up to approximately 1000V, depending on electrical resistance of the metal foil.
  - 24. The system of claim 17, the metal foil having a thickness of approximately 0.5 μ
    - m to 1 mm.
  - 25. The system of claim 17, the metal foil comprising one of conductive polymer film, carbon-fiber composite material and carbon nanotube composite material.

18.

26. An ice making system, comprising:
- an ice-container for converting water to ice when cooled;
  
  a capillary tube located with the base of the ice-container;
  
  a power supply operable to apply pulse heating energy to the ice-container and to the capillary tube;
  
  wherein the pulse heating melts an interfacial layer of ice in the ice-container and evaporates ice in the capillary tube to eject ice from the ice-container.
- View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
- - 27. The system of claim 26, further comprising a switch operable to connect the power supply to the ice-container to generate pulse heating energy within the ice-container.
  - 28. The system of claim 26, further comprising a switch operable to connect the power supply to the capillary tube to generate pulse heating within the capillary tube, to evaporate ice therein.
  - 29. The system of claim 26, the ice-container being made of stainless steel.
  - 30. The system of claim 29, the foil being about 0.1-mm in thickness.
  - 31. The system of claim 26, the capillary tube being made of stainless steel.
  - 32. The system of claim 26, wherein the ice-container forms a frustum-like shape.
  - 33. The system of claim 26, the power supply comprising AC power or DC power supply.
  - 34. The system of claim 26, the power supply comprising a battery, capacitor or ultracapacitor.
  - 35. The system of claim 26 further comprising at least one switch, used to selectively apply the pulse heating energy to the ice-container and the capillary.
  - 36. The system of claim 35, the switch comprising a power-MOSFET, IGBT, thyristor, mechanical switch, an electromagnetic switch, or combinations thereof.
  - 37. The system of claim 26, wherein pulse heating is applied within about 1 second and generates about a 230-Joule pulse of current to the container to melt the interfacial layer.
  - 38. The system of claim 26, wherein pulse heating of the capillary is applied within about 0.125 second and generates about a 860-Joule pulse of current to evaporate ice inside the capillary.

39. An evaporative de-icing system, comprising:
- resistive film disposed upon an object to be deiced;
  
  an array of capillaries disposed with the object such that an open end of each of the capillaries is flush with the surface of the object; and
  
  a power supply operable to (a) supply energy to the resistive film, to generate pulse heating energy within the resistive film such that an interfacial layer of ice adjacent to the resistive film melts, and (b) supply energy to the capillaries, to evaporate ice within the capillaries and eject ice from the object.
- View Dependent Claims (40)
- - 40. The evaporative de-icing system of claim 39, the capillaries being placed on a stagnation line of an airplane wing.

41. An evaporative de-icing system, comprising:
- a resistive film disposed upon a surface of an object to be deiced;
  
  a strip of porous metal foil; and
  
  a power supply operable to (a) supply energy to the resistive film, to generate pulse heating energy within the resistive film such that an interfacial layer of ice adjacent to the resistive film melts, and (b) supply energy to the strip of porous metal, to evaporate ice within the strip of porous metal and eject ice from the object.
- View Dependent Claims (42)
- - 42. The evaporative de-icing system of claim 41, the porous metal foil being placed on a stagnation line of an airplane wing.

43. A system for de-icing a refrigerator, comprising:
- a heat exchanger having an accordion-type surface;
  
  a wall pipe for flowing coolant therein; and
  
  a power supply electrically switched to the heat exchanger to apply pulse heating power to the heat exchanger and remove ice therefrom.
- View Dependent Claims (44, 45)
- - 44. The system of claim 43, further comprising an insulating film positioned on top of the heat exchanger, the insulating film being made of anodized aluminum or anodized aluminum alloy.
  - 45. The system of claim 44, further comprising a conductive film positioned on top of the insulating film wherein the conductive film is a thin metal layer applied by CVD, PVD, electrolysis coating, or painting.

46. A system for de-icing a heat exchanger having a base tube and a plurality of fins attached thereto, comprising:
- a power supply; and
  
  a switch for connecting the power supply to the base tube;
  
  wherein the switch operates to apply a pulse of electrical current to the base tube such that joule heating raises the temperature of the base tube and the fins, to melt ice attached thereto.
- View Dependent Claims (47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65)
- - 47. The system of claim 46, the base tube and the fins being made from the same continuous piece of metal.
  - 48. The system of claim 46, further comprising a thin layer of dielectric material disposed between the base tube and the fins.
  - 49. The system of claim 46, wherein the base tube and fins are made of one or more of copper, aluminum, stainless steel, metal alloy, conductive polymer, and electrically and thermally conductive composite material.
  - 50. The system of claim 46, wherein a density of heating power applied to the base tube is in a range from 0.5 kW/kg to 50 kW/kg, where the weight refers to the weight of the heat exchanger.
  - 51. The system of claim 46, wherein the switch operates to supply a pulse of a current with duration approximately in a range from 0.1 s to 30 s.
  - 52. The system of claim 46, wherein the power source is a DC power source.
  - 53. The system of claim 52, wherein the power source generates an electric field strength within the base tube approximately in a range of 0.5 V/m to 50 V/m, depending on electrical resistivity of the base tube material.
  - 54. The system of claim 46, wherein the power source is an AC power source.
  - 55. The system of claim 54, wherein the AC power source induces an electric field strength within the base tube approximately in a range of 0.5 V/m to 50 V/m, depending on electrical resistivity of the base tube material.
  - 56. The system of claim 54, wherein the AC power source operates with a frequency in an approximate range from 50 Hz to 10 MHz.
  - 57. The system of claim 54, wherein the frequency of the AC power source is adjusted such that a desirable electrical resistance of the base tube is reached due to Skin-effect.
  - 58. The system of claim 46, wherein the energy of the pulse of electricity is sufficient to melt a thin layer of frost or ice attached to the heat exchanger.
  - 59. The system of claim 46, wherein the energy of the pulse of electricity is sufficient to melt a thick layer of frost or ice.
  - 60. The system of claim 59, wherein the switch operates to supply a plurality of electrical pulses at a frequency and duration sufficient to maintain the surface of the heat-exchanger free from ice and frost.
  - 61. The system of claim 46, further comprising a thin-film ice detector attached to the outer surface of the heat exchanger for detecting presence of ice and/or frost.
  - 62. The system of claim 61, wherein the ice detector measures thickness of the ice and frost.
  - 63. The system of claim 62, further comprising control electronics that utilize the ice detector to monitor the ice and frost thickness.
  - 64. The system of claim 63, wherein the control electronics activate the switch when ice thickness reaches a preset value.
  - 65. The system of claim 63, wherein the control electronics deactivate the switch when all ice or/and frost on the heat exchanger is melted.

66. An ice making system comprising:
- a cold plate;
  
  a metal foil cooled by the cold plate through the dielectric film, such that water adjacent the metal foil forms ice thereon;
  
  a power supply; and
  
  a switch operable to couple current from the power supply to the meal foil, to generate a heating pulse that melts an interfacial layer of the ice at the metal foil and release the ice;
  
  wherein the heating pulse has a heat pulse energy, Q, determined by;
  
  $Q (W, d, l_{m}) = S \cdot {(\frac{b (W, d)}{2} + \sqrt{\frac{{b (W, d)}^{2}}{4} + c (l_{m}, d)})}^{2},$ where S is the area of the metal foil, b(W, d) is, $b (W, d) = \frac{\sqrt{λ_{i} \cdot ρ_{i} \cdot C_{i}}}{\sqrt{W - \frac{Δ T \cdot λ_{d}}{2 d}}} \cdot Δ T \cdot \frac{\sqrt{π}}{2}$ and C(l_m, d) is, $C (l_{m}, d) = C_{h} \cdot ρ_{h} \cdot d_{h} \cdot Δ T + (ρ_{w} \cdot l_{m} \cdot q_{latent}) + \frac{Δ T \cdot ρ_{d} \cdot d \cdot C_{d}}{2} .$

67. An ice making system, comprising:
- a cold plate;
  
  a metal foil cooled by the cold plate through the dielectric film, such that water adjacent the metal foil forms ice thereon;
  
  a power supply; and
  
  a switch operable to couple cement from the power supply to the metal foil, to generate a heating pulse that melts an interfacial layer of the ice at the metal foil and release the ice;
  
  wherein a duration of the heating pulse is determined by;
  
  $t (W, d, l_{m}) = \frac{Q (W, d l_{m})}{S \cdot W},$ S is the area of the metal foil, W is power density applied to the dielectric, Q(W, d l_m) is, $Q (W, d, l_{m}) = S \cdot {(\frac{b (W, d)}{2} + \sqrt{\frac{{b (W, d)}^{2}}{4} + c (l_{m}, d)})}^{2},$ h(W, d) is, $b (W, d) = \frac{\sqrt{λ_{i} \cdot ρ_{i} \cdot C_{i}}}{\sqrt{W - \frac{Δ T \cdot λ_{d}}{2 d}}} \cdot Δ T \cdot \frac{\sqrt{π}}{2}$ and C(l_m, d) is, $C (l_{m}, d) = C_{h} \cdot ρ_{h} \cdot d_{h} \cdot Δ T + (ρ_{w} \cdot l_{m} \cdot q_{latent}) + \frac{Δ T \cdot ρ_{d} \cdot d \cdot C_{d}}{2} .$

68. An ice making system, comprising:
- a cold plate;
  
  a metal foil cooled by the cold plate through the dielectric film, such that water adjacent the metal foil forms ice thereon;
  
  a power supply; and
  
  a switch operable to couple current from the power supply to the metal foil, to generate a heating pulse that melts an interfacial layer of the ice at the metal foil and release the ice;
  
  wherein the time requited to release the ice is determined by;
  
  $t_{r} (W, d, l_{m}) = \frac{a (W, d, l_{m})}{b (d)} + \frac{1}{2 \cdot {b (d)}^{2}} - \sqrt{\begin{matrix} {(\frac{a (W, d, l_{m})}{b (d)} + \frac{1}{2 \cdot {b (d)}^{2}})}^{2} + \\ \frac{t (W, d, l_{m})}{{b (d)}^{2}} - \frac{{a (W, d, l_{m})}^{2}}{{b (d)}^{2},} \end{matrix}}$ where α
  
  (W, d, l_m) is, $a (W, d, l_{m}) = \sqrt{t (W, d, l_{m})} + \frac{ρ_{w} \cdot l_{m} \cdot q_{latent}}{Δ T \cdot \sqrt{λ_{i} \cdot ρ_{i} \cdot C_{i} \cdot}},$ b(d) is, $b (d) = \frac{λ_{d}}{d \sqrt{λ_{i} \cdot ρ_{i} \cdot C_{i}}},$ and t(W, d, l_m) is, $t (W, d, l_{m}) = \frac{Q (W, d, l_{m})}{S \cdot W},$

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Current Assignee
The Trustees of Dartmounth College (Dartmouth College)
Original Assignee
The Trustees of Dartmounth College (Dartmouth College)
Inventors
Petrenko, Victor

Granted Patent

US 7,703,300 B2
Time in Patent Office

Days
Field of Search
US Class Current

62/3.1
CPC Class Codes

B64D 15/12   by electric heating electri...

F25C 5/08   by heating bodies in contac...

F28F 17/00   Removing ice or water from ...

PULSE SYSTEMS AND METHODS FOR DETACHING ICE

First Claim

1 Assignment

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Abstract

142 Citations

68 Claims

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PULSE SYSTEMS AND METHODS FOR DETACHING ICE

First Claim

1 Assignment

Subscription Required

Subscription Required

0 Petitions

Subscription Required

Accused Products

Subscription Required

Abstract

142 Citations

68 Claims

Specification

Subscription Required

Use Cases

Quick Links

Others