Hydrodynamic brush seal - US Patent 7182345

www.patentstorm.us/patents/7182345-claims.html

Abstract
A hybrid brush seal is provided having two bundles of axially spaced seal bristles each of which are mounted in a ring shape on a first machine component with bristle ends directed at a sealing surface of the second, rotating machine component. The bristle ends are kept from direct contact with the rotating machine component via one or more shoes which are designed such that as the shaft rotates a hydrodynamic film separates the shoe(s) from the shaft. The shoe(s) is attached to the bristle ends at discreet locations. Alternatively, one or more bundles of seal bristles are mounted at one end either to the fixed or rotating machine component, with the opposite bristle ends directed toward one or more shoes, and wherein one or more spring elements are connected between the machine component and shoes.

Sealing Technology : Measurements of leakage, structural stiffness ...

Measurements of leakage, structural stiffness and energy dissipation parameters in a shoed brush seal www.linkinghub.elsevier.com/retrieve/pii/S135047890670993X

Volume 2005, Issue 12, December 2005, Pages 7-10

Adolfo Delgado, Luis San Andrés and John F Justak
^aTexas A&M University, USA
^bAdvanced Technologies Group Inc, Stuart, Florida, USA
Available online 8 February 2006.

Abstract                                                                                                                                                                                                                                                        The shoed brush seal is a modification of a standard brush seal that has a number of arcuate pads at the free ends of the bristles. A major benefit of this novel design is that it allows reverse shaft rotation. It also eliminates bristle wear as the pads lift off due to the generation of a hydrodynamic film during rotor spinning. This type of seal, able to work at both low and high temperatures, not only restricts secondary leakage but also acts as an effective vibration damper. The dynamic operation of the shoed-brush seals, along with the validation of reliable predictive tools, relies on the correct estimation of the seal structural stiffness and energy dissipation features. This article describes tests to measure these parameters and compare the results with predictions.

TRIBGROUP_TAMU

Rotordynamics Laboratory - Turbomachinery Laboratory ? Texas A&M University
phn.tamu.edu/TRIBGroup/

Hybrid Brush Seals for Gas Turbines

Sponsor: Siemens-westinghouse 2006-2008. Hardware from Advanced Turbomachinery Solutions (ATS)
Objective: Measure leakage versus pressure for increasing shaft speeds, identify mechanical parameters from improved shoed brush seal and advance computational models for prediction of the dynamic forced performance of shoed brush seals.
status: Test rig for identification of stiffness and damping coefficients revamped for tests at high temperature (300C). Shaker load tests at various frequencies will be conducted to identify the stiffness and equivalent damping coefficients of shoed brush seal. Leakage vs. supply pressure tests completed.

Abstract

A hybrid brush seal is provided having two bundles of axially spaced seal bristles each of which are mounted in a ring shape on a first machine component with bristle ends directed at a sealing surface of the second, rotating machine component. The bristle ends are kept from direct contact with the rotating machine component via one or more shoes which are designed such that as the shaft rotates a hydrodynamic film separates the shoe(s) from the shaft. The shoe(s) is attached to the bristle ends at discreet locations. Alternatively, one or more bundles of seal bristles are mounted at one end either to the fixed or rotating machine component, with the opposite bristle ends directed toward one or more shoes, and wherein one or more spring elements are connected between the machine component and shoes.