Looped fin heat exchanger and method for making same
OwnerRoy W. Abbottinventor
Life of this patent
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Abstract
Heat transfer device effective in minimizing frost bridging in refrigeration operations to be wound helically onto a refrigerant-carrying tube, having an integrally formed chain of looped fins, each fin having a mounting flange at each end of the chain, a vertical fin member extending from each mounting flange connected to a bridge portion; and a method and apparatus for making same including a unitary stretch preforming process to reform the beginning fin stock into final looped fin shape in a single forming step.
Claims19
A refrigerant evaporator characterized by improved heat transfer and frost tolerance, comprising a tube and a chain of looped fins wound around said tube so that adjacent turns of said chain are spaced so that there are about 2.5 to about 4 turns per inch of tube, said chain of looped fins comprising a mounting flange at each end of said chain and a plurality of looped fins between said flanges, each of said fins comprising leg members extending vertically outward from each of said mounting flanges and a substantially straight bridge member, at least about 0.12 inches long and substantially parallel to said tube, connecting said leg members at the distal ends of the leg members.
In a refrigerator evaporator adapted to be cooled to a temperature below the freezing point of water with moist air passing over the surface of said evaporator, the improvement wherein said evaporator comprises a tube and a chain of looped fins would helically around said tube so that adjacent turns of said chain are spaced so that there are about 2.5 to about 4 turns per inch of tube, said chain of looped fins comprises a mounting flange at each edge of said chain and a plurality of looped fins between said flanges, each of said fins comprising leg members extending vertically outward from each of said mounting flanges and a bridge section connecting the leg members at the distal ends of the leg members, and said bridge section is designed and adapted to inhibit retention of a meniscus of water between said leg members.
A method of making a looped fin heat transfer device comprising the steps of:
- (a) providing an elongate ribbon of thermally conductive material;
- (b) transversely separating and forming said ribbon into an intermediate configuration having a pair of imperforate opposing side portions interconnected by separated web portions extending therebetween;
- (c) stretching said imperforate side portions of said intermediate configuration to reform the same into a subsequent configuration comprising an integrally formed chain of looped fins, said chain comprising an a mounting flange reformed from each of said imperforate opposing side portions at each edge of said chain and a plurality of fins between said mounting flanges, reformed from said separated web portions, each of said fins comprising leg members extending outwardly from each of said mounting flanges and a bridge section connecting said leg members at the respective distal ends of said leg members;
- and
- (d) winding said chain helically around a tube so that adjacent turns of said chain are spaced from about 2.5 to about 4 turns per inch of tube, and such that said mounting flanges contact the exterior of said tube.
Dependencies are inferred from the claim text.