Method of, and apparatus for, de-icing an aircraft by infrared radiation

Abstract

An improved apparatus (11) for emitting infrared radiation of a desired wavelength includes a primary surface (.[.35.]. .Iadd.25.Iaddend.); a burner (24) for raising the temperature of the primary surface so as to cause the primary surface to emit infrared radiation of a first wavelength; a secondary surface (26) surrounding the primary surface in spaced relation thereto and arranged to be heated by infrared radiation emitted by the first surface and for emitting infrared radiation of a second wavelength toward the object; and an actuator (28) for selectively varying the spacing between the primary and secondary surfaces so that infrared radiation emitted by the secondary surface .[.will be at a desired wavelength and.]. will be focused; whereby the apparatus will emit infrared radiation of a desired wavelength toward the object. The improved apparatus may be used in a method of de-icing a portion of an aircraft, which includes the steps of: providing a structure (10) having an infrared heater (23); moving an aircraft relative to the structure to a position adjacent the heater; operating the heater so as to emit radiation toward the object; and controlling the wavelength of radiation emitted by the heater; thereby to melt snow and ice from the aircraft portion.

What is claimed is: 
     
       1. A method of de-icing a portion of an object, comprising .[.the steps of.].: .Iadd.(a) .Iaddend.providing a structure having a source of infrared radiation, said source including a first means for emitting infrared radiation of a first wavelength and a second means spaced from said first means and heated by the infrared radiation emitted by said first means for emitting infrared radiation of a second.Iadd., predetermined .Iaddend.wavelength;   .Iadd.(b) .Iaddend.moving an object relative to said structure to a position adjacent .Iadd.to .Iaddend.said source of infrared radiation;   .Iadd.(c) .Iaddend.operating said source of infrared radiation so as to emit infrared radiation of said second wavelength toward the portion of said object to be de-iced; and   .Iadd.(d) .Iaddend..[.controlling the second wavelength of the radiation emitted by said source of infrared radiation by.]. adjusting the spacing between the first means and the second means, thus controlling the .[.emitted.]. .Iadd.distribution of .Iaddend.infrared radiation .[.distribution.]. .Iadd.emitted at the second wavelength .Iaddend.so as to .[.maximize the absorption of.]. .Iadd.concentrate .Iaddend.such radiation .[.by.]. .Iadd.on .Iaddend.any snow and ice to be melted from said object portion;   .Iadd.(e) .Iaddend.thereby to provide radiant infrared energy at a high .[.output.]. .Iadd.concentration .Iaddend.and at a desired wavelength to melt the snow and ice from said object portion.   
     
     
       2. The method as set forth in claim 1, .[.and.]. further comprising .[.the additional step of:.]. physically removing accumulations or ice and snow from said object portion .[.prior to the step of.]. .Iadd.before .Iaddend.operating said source of infrared radiation. 
     
     
       3. The method as set forth in claim 1, .[.and.]. further comprising .[.the additional step of:.]. drying said object portion after ice and snow have been melted therefrom. 
     
     
       4. The method as set forth in claim 3, .[.and.]. further comprising .[.the additional step of:.]. applying an anti-icing chemical to said object portion after snow and ice have been melted therefrom. 
     
     
       5. The method as set forth in claim 1, .[.and.]. further comprising .[.the additional step of:.]. applying an anti-icing chemical to said object portion after snow and ice have been melted therefrom. 
     
     
       6. The method as set forth in claim 1, .[.and.]. further comprising .[.the additional step of:.]. focusing such emitted radiation distribution .Iadd.at .Iaddend.said object portion. 
     
     
       7. The method as set forth in claim 1, wherein said source of infrared radiation further comprises: .Iadd.(a) .Iaddend.said first means comprising a primary surface;   .Iadd.(b) .Iaddend.a heater for raising the temperature of said primary surface so as to cause said primary surface to emit said infrared radiation of said first wavelength;   .Iadd.(c) .Iaddend.said second means comprising a secondary surface surrounding said primary surface in spaced relation thereto and arranged to be heated by said infrared radiation emitted by said primary surface for emitting said infrared radiation at said second wavelength toward said object; .[.and.].   .Iadd.(d) .Iaddend.an actuator for selectively varying the spacing between said primary and secondary surfaces so that said infrared radiation emitted by said secondary surface .[.will be.]. at said .[.desired.]. .Iadd.second .Iaddend.wavelength .[.and.]. will be focused.   
     
     
       8. A method of heating a portion of an object, comprising .[.the steps of.].: .Iadd.(a) .Iaddend.providing a structure having an infrared heater, a first means for emitting infrared radiation of a first wavelength, and a second means spaced from said first means and heated by the infrared radiation emitted by said first means for emitting infrared radiation of a second wavelength;   .Iadd.(b) .Iaddend.moving an object relative to said structure to a position adjacent to said heater;   .Iadd.(c) .Iaddend.operating said heater so as to emit infrared radiation of said second wavelength toward the portion of said object to be heated; and   .Iadd.(d) .Iaddend..[.controlling the second wavelength of the radiation emitted by said heater by.]. adjusting the spacing between the first means and the second means, thus controlling the .[.emitted.]. .Iadd.distribution of .Iaddend.infrared radiation .[.distribution.]. .Iadd.emitted at the second wavelength .Iaddend.so as to maximize the absorption of such radiation by said object portion; thereby to heat said object portion.     
     
     
       9. Apparatus for emitting infrared radiation of a desired wavelength toward an object, comprising: .Iadd.(a) .Iaddend.a primary surface;   .Iadd.(b) .Iaddend.a heater for raising the temperature of said primary surface so as to cause said primary surface to emit infrared radiation of a first wavelength;   .Iadd.(c) .Iaddend.a secondary surface surrounding said primary surface in spaced relation thereto and arranged to be heated by infrared radiation emitted by said primary surface and for emitting infrared radiation of a second wavelength toward said object; and   .Iadd.(d) .Iaddend.an actuator for selectively varying the spacing between said primary and secondary surfaces so that infrared radiation emitted by said secondary surface .[.will be.]. at .[.a desired.]. .Iadd.the second .Iaddend.wavelength .[.and.]. will be focused;   .Iadd.(e) .Iaddend.whereby said apparatus will emit infrared radiation of a desired wavelength toward said object.   
     
     
       10. The apparatus as set forth in claim 9 wherein said primary surface is frusto-conical.[.,.]. and faces away from said object. 
     
     
       11. The apparatus as set forth in claim 10 wherein a portion of said secondary surface is frusto-conical.[.,.]. and faces toward said object. 
     
     
       12. The apparatus as set forth in claim 9 wherein said heater has an elongated tube, and wherein said secondary surface is slidably mounted on said tube. 
     
     
       13. The apparatus as set forth in claim 9 wherein said object is an aircraft having a substance thereon, and wherein the wavelength of infrared radiation emitted by said secondary surface is the wavelength of maximum absorptivity of said substance. .Iadd.14. Apparatus for emitting infrared radiation of a desired wavelength toward an object, comprising: (a) a heat source;   (b) a first heat exchanger substantially surrounding the heat source and shaped and positioned relative to the heat source so as to radiate heat a first wavelength when the heat source operates;   (c) a second heat exchanger substantially surrounding the first heat exchanger and shaped to radiate heat at a second wavelength when the heat source operates; and   (d) an actuator coupled to the first and second heat exchangers in such a way as to controllably vary the spacing between the first and second heat exchanger. .Iaddend..Iadd.15. The apparatus of claim 14 wherein part of the second heat exchanger is insulated, whereby heat is radiated at the second wavelength only from a portion of the second heat exchanger. .Iaddend..Iadd.16. The apparatus of claim 14 wherein the second heat   
     
     
        exchanger is formed in a frusto-conical shape. .Iaddend..Iadd.17.  The apparatus of claim 14 wherein the first and second heat exchangers are shaped and relatively positioned so that varying the spacing between the first and second heat exchangers changes the trajectory of at least some of the heat radiated by the second heat exchanger. .Iaddend..Iadd.18. The apparatus of claim 14 wherein the second heat exchanger is positioned to intercept substantially all of the heat radiated by the first heat exchanger. .Iaddend..Iadd.19. A method of de-icing an object comprising: (a) providing a structure having: (i) a heat source,   (ii) a first heat exchanger spaced from the heat source, and   (iii) a second heat exchanger spaced from the first heat exchanger and having a shape selected to radiate heat at a selected and desired wavelength when the heat source operates;     (b) positioning an object relative to said structure; and   (c) operating the heat source, thereby heating the first heat exchanger and causing the first heat exchanger to radiate infrared radiation at a first wavelength in the direction of the second heat exchanger, thereby causing the second heat exchanger to absorb the infrared radiation of the first wavelength and radiate infrared radiation at the desired wavelength toward the object. .Iaddend..Iadd.20. The method of claim 19 wherein the object is a surface of an aircraft and wherein the desired wavelength is the   
     
     
        wavelength of maximum absorptivity of snow and ice. .Iaddend..Iadd.21. The method of claim 19 wherein providing a structure includes using a structure wherein the first heat exchanger surrounds the heat source. .Iaddend..Iadd.22. The method of claim 21 wherein providing a structure includes using a structure wherein the second heat exchanger surrounds the 
     
     
        first heat exchanger. .Iaddend..Iadd.23.  The method of claim 19 wherein part (d) comprises causing the second heat exchanger to absorb a substantial portion of the infrared radiation radiated at the first 
     
     
        wavelength by the first heat exchanger. .Iaddend..Iadd.24.  A method of de-icing an object comprising: (a) providing a structure having: (i) a heat source,   (ii) a first heat exchanger spaced from the heat source, and   (iii) a second heat exchanger spaced from the first heat exchanger and having a shape selected to radiate heat at a selected and desired wavelength when the heat source operates;     (b) positioning an object relative to said structure;   (c) operating the heat source, thereby heating the first heat exchanger and causing the first heat exchanger to radiate infrared radiation at a first wavelength in the direction of the second heat exchanger, thereby causing the second heat exchanger to absorb the infrared radiation of the first wavelength and radiate infrared radiation at the desired wavelength toward the object; and   (d) adjusting the spacing between the first heat exchanger and the second heat exchanger, thus control the distribution of radiated infrared   
     
     
        radiation. .Iaddend..Iadd.25.  The method of claim 24 wherein controlling the radiation distribution comprises focusing the radiation at the object. .Iaddend.