Claims
- 1. A self-grounding duct for transporting corrosive vapors and gases comprising a laminated inner wall comprising:
an innermost layer formed of a cured epoxy vinyl ester resin and having a preselected thickness determined by an interior surface and an exterior surface; and a plurality of electrically conductive, continuous ribbons each having a multiplicity of longitudinal filaments impregnated with said cured epoxy vinyl ester resin, a preselected width determined by opposed generally parallel edges, and a preselected thickness, said ribbons disposed contiguously edge-to-edge to form a carbon band of a preselected width, said carbon band wound in a first plurality of contiguous helical segments forming a continuous first ribbon-layer embedded in said innermost layer and integrated with said interior surface, said first ribbon-layer in a preselected percentage-by-weight relative to the weight of the cured resin.
- 2. The duct of claim 1 wherein said filaments are continuous carbon fibers manufactured from polyacrylonitrile precursor.
- 3. The duct of claim 2 wherein the percentage-by-weight of said filaments is in a range from about 50 to about 70 percent, and the percentage-by-weight of said cured epoxy vinyl ester resin is in a range from about 30 to about 50 percent.
- 4. The duct of claim 2 wherein the thickness of said innermost layer is about 0.002- to 0.003-inch, and the thickness of each said ribbon and said first ribbon-layer is about 0.010-inch.
- 5. The duct of claim 2, further comprising a plurality of ribbon-layers, bounded by an inner ribbon-layer superposed on said first ribbon-layer and an outer ribbon-layer, formed by successive helical windings of said carbon band, the filaments of the ribbons forming said carbon band impregnated with said cured epoxy vinyl ester resin, said outer ribbon-layer coated with a layer of said cured epoxy vinyl ester resin of a preselected thickness.
- 6. The duct of claim 5, wherein the combined thickness of said first ribbon-layer and said plurality of ribbon-layers is about 0.050- to 0.060-inch, and the thickness of said cured epoxy vinyl ester resin layer is about 0.002- to 0.003-inch.
- 7. The duct of claim 5, further comprising a layer of mat-type fiberglass of a preselected weight and thickness and having an outer surface, impregnated with said cured epoxy vinyl ester resin and helically wound over said outer ribbon-layer.
- 8. The duct of claim 7, wherein said preselected weight of said mat-type fiberglass is about 0.75 ounce per square yard, and said thickness is in a range of about 0.025- to 0.032-inch.
- 9. The duct of claim 7, further comprising a laminated outer wall comprising:
an innermost layer formed of a cured phenolic resin and having a preselected thickness determined by an interior surface and an exterior surface, said interior surface contiguous to said outer surface of said layer of mat-type fiberglass; a plurality of continuous ribbons each having a multiplicity of longitudinal glass filaments of a preselected weight impregnated with said cured phenolic resin, a preselected width determined by opposed generally parallel edges, and a preselected thickness, said ribbons disposed contiguously edge-to-edge to form a glass band of a preselected width, said glass band wound helically as a first plurality of ribbon-layers bounded by a first inner ribbon-layer integrated with said phenolic resin layer and a first outer ribbon-layer, forming a first glass layer of a first predetermined thickness; and additional glass band, impregnated with said cured phenolic resin, wound helically as a second plurality of ribbon-layers bounded by a second inner ribbon-layer, contiguous to said first outer ribbon-layer, and a second outer ribbon-layer, forming a second glass layer of a second predetermined thickness.
- 10. The duct of claim 9, wherein said preselected weight of the glass filament is about 250 feet per pound, and the combined thickness of said first and second glass layers is in a range of about 0.062-inch to about 0.625-inch.
- 11. The duct of claim 9, said outer wall further comprising a layer of glass veil, impregnated with said cured phenolic resin and having a preselected thickness determined by an inner surface and an outer surface, helically wound around said second glass layer, said inner surface contiguous to said second outer ribbon-layer.
- 12. The duct of claim 11, wherein said thickness of the glass veil is about 0.010-inch.
- 13. A duct in accordance with claim 11 having an end portion terminating in an edge portion determined by circumferential inner and outer surfaces, said edge portion closely receiving a first portion of a generally cylindrical laminated collar having an opposed second portion, said first and second portions symmetric with respect to a circumferential rib, said collar second portion closely received within an edge portion terminating in an end portion, determined by circumferential inner and outer surfaces, of a second duct in accordance with claim 11, said collar having first and second layers of carbon ribbon-layers and a epoxy vinyl ester impregnating resin admixture, and an outer layer of glass ribbon-layers and said epoxy vinyl ester resin admixture, said duct edge inner and outer surfaces and collar portions circumferentially sealed with a curable sealant composition comprising, per 100 parts-by-weight thereof, about 10 to 30 parts-by-weight of a hardener, and about 10 to 60 parts-by-weight of carbon fibers.
- 14. A process for fabricating a dual wall laminated self-grounding duct for transporting corrosive vapors and gases, comprising the steps of:
forming a vinyl ester fluidic admixture of an epoxy vinyl ester resin and a curing agent therefor in a preselected percentage-by-weight, relative to the weight of the resin, as a supply source of the same; evenly coating a generally horizontal mandrel covered with a polyester sheeting with a first layer of said vinyl ester fluidic admixture, said first layer having an interior surface contiguous to the polyester sheeting and an exterior surface, the interior and exterior surfaces determining a preselected layer thickness, the mandrel symmetric about a longitudinal axis; helically winding around the mandrel, at a first preselected angle relative to the mandrel longitudinal axis, a carbon band of a preselected width comprising a plurality of electrically conductive, continuous ribbons each having a multiplicity of continuous longitudinal carbon filaments impregnated with said vinyl ester fluidic admixture, said ribbons having a common preselected width determined by opposed generally parallel edges and a preselected thickness, and disposed contiguously edge-to-edge, said carbon band wound in a first plurality of contiguous helical segments forming a continuous first ribbon-layer embedded in said first layer of said vinyl ester fluidic admixture and integrated with said interior surface, said first ribbon-layer in a preselected percentage-by-weight relative to the weight of said vinyl ester fluidic admixture; helically winding additional carbon band at said first preselected angle, thereby forming a plurality of ribbon-layers of a cumulative preselected thickness bounded by an inner ribbon-layer superposed on said first-ribbon layer and an outer ribbon-layer; evenly coating said outer ribbon-layer with a second layer of said vinyl ester fluidic admixture of a preselected thickness; rolling out air trapped in said ribbon-layers; helically winding over said outer ribbon-layer and second admixture layer a layer of mat-type fiberglass, of a preselected weight and thickness, having an outer surface post-wetted with said vinyl ester admixture; and curing said admixture.
- 15. The process of claim 14, wherein:
the thickness of each said first and second vinyl ester admixture layer is in a range from 0.002- to 0.003-inch; said first preselected angle is in a range from about 55 to about 72 degrees; the total thickness of said carbon filament ribbon-layers is in a range from 0.050-inch to 0.060-inch; and the percentage-by-weight of said ribbon-layers is in a range from about 50 to about 70 percent, and the percentage-by-weight of said impregnating vinyl ester admixture is in a range from about 30 to about 50 percent.
- 16. The process of claim 14, further comprising the steps of:
forming a phenolic fluidic admixture of a phenolic impregnating resin, and a catalyst therefor in a preselected percentage-by-weight, relative to the weight of the resin, as a supply source of the same; evenly coating said outer surface of said mat-type fiberglass layer with a layer of said phenolic fluidic admixture of a preselected thickness; helically winding around said mat-type fiberglass outer surface and said phenolic admixture layer, at a second preselected angle relative to the mandrel longitudinal axis, a glass band of a preselected width comprising a plurality of continuous glass filament ribbons impregnated with said phenolic fluidic admixture, said glass filament of a preselected weight, said ribbons having a common preselected width determined by opposed generally parallel edges and a preselected thickness, and disposed contiguously edge-to-edge, said glass band wound in a first plurality of glass ribbon- layers of a total preselected thickness forming an inner glass layer; rolling out air trapped in said first plurality of ribbon-layers; helically winding around said inner glass layer, at said second preselected angle, additional glass band in a second plurality of glass ribbon-layers of a total preselected thickness forming an outer glass layer; rolling out air trapped in said second plurality of ribbon-layers; helically winding around said outer glass layer a layer of glass veil of a preselected thickness, wetted with said phenolic fluidic admixture; and curing said admixture.
- 17. The process of claim 16, wherein:
the thickness of said phenolic admixture layer is in a range from 0.002- to 0.003-inch; said second preselected angle is in a range from about 55 to about 72 degrees; the total thickness of said inner and outer glass layers is in a range from about 0.062-inch to 0.625-inch; and the percentage-by-weight of said ribbon-layers is in a range from about 50 to about 75 percent, and the percentage-by-weight of said phenolic admixture is in a range from about 25 to about 50 percent.
- 18. The process of claim 17 wherein the percentage-by-weight of said ribbon-layers is in a range from about 60 to about 65 percent, and the percentage-by-weight of said phenolic admixture is in a range from about 35 to about 40 percent.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of application Ser. No. 09/603,468 filed Jun. 26, 2000, entitled “Electrostatic Charge Neutralizing Fume Duct,” now pending.
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
09603468 |
Jun 2000 |
US |
Child |
09882683 |
Jun 2001 |
US |