Partial shroud with perforating for VIV suppression, and method of using
AssigneeShell Oil Company
InventorsDonald W. Allen, Dean L. Henning
Life of this patent
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Abstract
Apparatus and methods for environments subject to vortex induced vibration. The system includes a shroud having a number of perforations, with the shroud encircling the flowing-fluid element less than 100%. The system further includes a separation member for attaching the shroud to the flowing-fluid element.
Claims33
A system for use with a flowing-fluid element subject to vortex induced vibration, said system comprising:
- (a) a shroud defining a plurality of perforations, wherein the shroud is suitable for placement around the flowing-fluid element, and wherein the shroud is suitable for providing a percent or encirclement of the flowing-fluid element in the range of about 12% to about 80%, wherein the shroud has a cross-sectional circular segment shape of from about 43° to about 288°, wherein said flowing-fluid element is subject to a fluid current having a direction, and wherein said shroud is centered around said flowing-fluid element at an angle in the range of about 62 to about 72 degrees relative to the direction of said current;
- and
- (b) at least one separation member in contact with the shroud, wherein the separation member is suitable for positioning between the flowing-fluid element and the shroud to maintain the shroud and flowing-fluid element in relative position to each other.
A system suitable for use in vortex induced vibration prone environments, said system comprising:
- (a) a flowing-fluid element;
- and
- (b) a shroud positioned around the flowing-fluid element, where the shroud defines a plurality of perforations, and wherein the shroud encircles the flowing-fluid element at a percent of encirclement in the range of about 12% to about 80%, and wherein the shroud has a cross-sectional circular segment shape of from about 43° to about 288°, and wherein said flowing-fluid element is subject to a fluid current having a direction, and wherein said shroud is centered around said flowing-fluid element at an angle in the range of about 62 to about 72 degrees relative to the direction of said current.
A method for modifying a flowing-fluid element subject to vortex induced vibration, said method comprising:
- (a) positioning a shroud around the flowing-fluid element, wherein the shroud defines a plurality of perforations, wherein the shroud is suitable for placement around the flowing-fluid element, and wherein the shroud is suitable for providing a percent of encirclement of the flowing-fluid element in the range of about 12% to about 80% and has a cross-sectional circular segment shape of about 43° to about 288°, and wherein said flowing-fluid element is subject to a fluid current having a direction, and wherein said shroud is centered around said flowing-fluid element at an angle in the range of about 62 to about 72 degrees relative to the direction of said current.
Dependencies are inferred from the claim text.