Fluid conduit wall inhibiting heat transfer and method for making
AssigneeGeneral Electric Company
InventorsJames Jay Witemyre, Jeffrey Glover, Robert J. Meek
Life of this patent
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Abstract
A fluid conduit wall enclosing a hollow interior for the flow of fluid includes an outer surface provided with a low emissivity coating having a coating emissivity of less than 0.2 and a thickness at least sufficient to provide the coating emissivity. One embodiment provides a fluid conduit with multiple spaced-apart walls. An outer surface of an inner wall of a first member and an inner surface of an outer wall of a second member define a gap therebetween. At least one of such surfaces includes the low emissivity coating. A method for providing such coating deposits the coating, for example by reactive vaporization, concurrently on both surfaces from within the gap after assembly of the members.
Claims20
A multiple spaced-apart wall fluid conduit enclosing a hollow interior for the flow of a fluid therein, comprising:
- a metal first conduit wall having a radially inner first surface enclosing the hollow interior and a radially outer second surface;
- and,
- a metal second conduit wall spaced apart radially outwardly from the first conduit wall and having a radially inner third surface spaced apart radially in juxtaposition with the outer second surface of the first wall to define a gap therebetween, wherein:
- the first conduit wall includes on the outer second surface a single layer first low emissivity metal coating, and the second conduit wall includes on the inner third surface a single layer second low emissivity metal coating;
- the first and second low emissivity coatings each having a coating emissivity of less than 0.2 and a coating thickness at least sufficient to provide the coating emissivity.
A multiple spaced-apart wall fluid conduit enclosing a hollow interior for the flow of fluid therein, comprising:
- a metal first conduit wall having a radially inner first surface enclosing the hollow interior and a radially outer second surface;
- and,
- a metal second conduit wall conduit wall spaced apart radially outwardly from the first conduit wall and having a radially inner third surface spaced apart radially in juxtaposition with the outer second surface of the first wall to define a gap therebetween, wherein:
- the first conduit wall includes on the outer second surface a single layer low emissivity metal coating;
- the low emissivity coating having a coating emissivity of less than 0.2 and a coating thickness at least sufficient to provide the coating emissivity.
A method for making a multiple spaced-apart wall fluid conduit enclosing a hollow interior for the flow of fluid therein, comprising:
- providing a first conduit member having a metal first wall including a radially inner first surface defining the hollow interior and a radially outer second surface of a first radial diameter, and a second conduit member having a metal second wall including a radially inner third surface of a second radial diameter greater than the first radial diameter;
- assembling the first conduit member co-axially with and radially within the second conduit member to provide an assembly with the outer first surface of the first member maintained radially spaced-apart from the inner third surface of the second member to define a gap therebetween;
- and then,
- depositing a low emissivity coating concurrently on each of the radially outer first surface of the first member and the radially inner third surface of the second member from within the gap.
Dependencies are inferred from the claim text.