Abstract: In a steam turbine, a combined brush and labyrinth seal is provided between a diaphragm web and axial projecting platforms on bucket dovetails at a location spaced radially outwardly of the outer diameter of the rotor. The downstream axially adjacent bucket dovetails also have platforms serving as complementary sealing surfaces to labyrinth teeth formed on the web. By locating the combined labyrinth and brush seal radially outwardly of the outer diameter of the shaft, thermal bowing of the rotor is eliminated. By providing backup labyrinth seals at the same radial location, axial thrust loads are eliminated in the event of brush seal failure.

Abstract: A brush seal segment includes a plurality of bristles disposed between a pair of backing plates. The bristles are welded to one another adjacent their proximal ends and to the edges of the backing plates remote from the bristle tips. An end plate is welded to the end faces of the backing plates at each of the opposite ends of the segment. Each end plate terminates at approximately one-half the length of the bristles along the end face to prevent the bristles from bending circumferentially and axially during handling while maintaining substantially uniform flexibility of the bristles throughout the entire length of the segment.

Abstract: A low leakage sealing system is provided between a steam pipe and a housing comprised of a pair of shells and a nozzle box movable relative to one another. The sealing system includes large and small diameter sealing rings engaging the pipe and shells or nozzle box and a secondary sealing element disposed between the sealing rings and one of the pipe and shells or nozzle box. The sealing elements comprise frustoconical elements having curved end surfaces forming primary seals with the sealing rings and the housing. In another form, the sealing system includes annular carrier elements having radially opening cavities for receiving sealing rings engageable with the pipe and housing, respectively. The carrier elements are axially spaced from a plurality of sealing rings to provide the low leakage sealing system.

Abstract: The adjoining edges of bucket covers are sealed one to the other. A brush seal projecting from a stationary shroud overlies the bucket covers. A joint at which the adjacent covers sealingly engage each other precludes radial outflow of high pressure fluid into bristles of the brush seal, preventing radial and axial deflection of the bristles and consequent failure of the bristles. The joints between the covers may comprise lap or tongue-and-groove joints.

Abstract: A brush seal is comprised of arcuate seal segments having ends cut in a radial direction with bristles “canted” at an approximate 45° angle relative to radii of the segments, leaving triangular regions adjacent one end of each segment devoid of bristles at the segment interfaces. The brush seals are retrofit into conventional labyrinth seals with the backing plate for the bristles comprising a labyrinth tooth profile extending fully 360° about the seal, including those areas where bristles are not present. The sealing capacity is not substantially degraded, while affording significant sealing improvements over conventional labyrinth seals. Additionally, when retrofit into labyrinth seals with radial movement, the individual labyrinth seal segments are free to move radially independently of one another during transients.

Abstract: A diaphragm has an annular groove formed of deep and shallow grooves with the deep groove opening into the shallow groove. A combination spill strip/brush seal is disposed in the groove. The brush seal comprises a pair of flexible bars secured to the proximal ends of the brush bristles by welding and is received in the shallow groove and a recess in an axial face of the spill strip. The spill strip has base portions extending into the deep groove. The combination spill strip/brush seal is secured in the annular groove by peening material of the diaphragm into the spill strip/brush seal combination. The brush seal may be used with different diameters of spill strips and diaphragm grooves.

Abstract: A diaphragm has an annular groove formed of deep and shallow grooves with the deep groove opening into the shallow groove. A combination spill strip/brush seal is disposed in the groove. The brush seal comprises a pair of flexible bars secured to the proximal ends of the brush bristles by welding and is received in the shallow groove and a recess in an axial face of the spill strip. The spill strip has base portions extending into the deep groove. The combination spill strip/brush seal is secured in the annular groove by peening material of the diaphragm into the spill strip/brush seal combination. The brush seal may be used with different diameters of spill strips and diaphragm grooves.

Abstract: The adjoining edges of bucket covers are sealed one to the other. A brush seal projecting from a stationary shroud overlies the bucket covers. A joint at which the adjacent covers sealingly engage each other precludes radial outflow of high pressure fluid into bristles of the brush seal, preventing radial and axial deflection of the bristles and consequent failure of the bristles. The joints between the covers may comprise lap or tongue-and-groove joints.

Abstract: A seal arrangement for a rotary machine, such as a turbine, includes a main seal segment such as a labyrinth seal segment, a brush seal segment disposed in a slot in the main seal segment and having a layer of bristles secured between upstream and downstream plates of the brush seal segment, and at least one passage radially formed through the main seal segment to communicate a balancing pressure from a pressure source located exteriorly of an outer periphery of the main seal segment to a cavity defined in the downstream plate of the brush seal segment at a downstream side of the layer of bristles of the brush seal segment.

Abstract: An arrangement and method for radially positioning a brush seal relative to a rotor provides a main seal segment having a slot open toward the rotor and an interior ledge facing away from the rotor, a brush seal segment in the slot and having an exterior shoulder facing toward the rotor and overlying the interior ledge such that the brush seal segment can move radially relative to the main seal segment and rotor and the exterior shoulder can move toward and away from the interior ledge, a shim disposed and establishing a minimum spacing between the interior ledge and the exterior shoulder, and set screws tightened into spaced threaded holes in the main seal segment forcing the exterior shoulder against the shim and to the minimum spacing from the interior ledge so as to prevent radial floating of the brush seal segment in the slot.

Abstract: A method for making a brush-tooth seal, such as a brush-tooth seal which is attachable to a turbine stator, includes obtaining a seal carrier having a groove and having seal teeth and obtaining a brush seal having bristles with tips. The brush seal is engaged in the groove and then attached to the seal carrier. Then, the tips of the bristles of the attached and engaged brush seal are cut, such as with an electric discharge machining (EDM) wire, at a predetermined distance from the longitudinal axis of the seal carrier.

Abstract: A method for overhauling a steam turbine to increase its power without increasing its overall length. Existing seal assemblies containing seals other than brush seals are replaced with longitudinally-shorter replacement seal assemblies having only brush seals. An existing turbine section, such as a high-pressure turbine section, is replaced with a longitudinally-longer replacement turbine section having additional stages (i.e., additional rows of rotating buckets or blades).

Abstract: A brush seal is comprised of arcuate seal segments having ends cut in a radial direction with bristles “canted” at an approximate 45° angle relative to radii of the segments, leaving triangular regions adjacent one end of each segment devoid of bristles at the segment interfaces. The brush seals are retrofit into conventional labyrinth seals with the backing plate for the bristles comprising a labyrinth tooth profile extending fully 360° about the seal, including those areas where bristles are not present. The sealing capacity is not substantially degraded, while affording significant sealing improvements over conventional labyrinth seals. Additionally, when retrofit into labyrinth seals with radial movement, the individual labyrinth seal segments are free to move radially independently of one another during transients.

Abstract: A brush seal is comprised of arcuate seal segments having ends cut in a radial direction with bristles “canted” at an approximate 45° angle relative to radii of the segments, leaving triangular regions adjacent one end of each segment devoid of bristles at the segment interfaces. The brush seals are retrofit into conventional labyrinth seals with the backing plate for the bristles comprising a labyrinth tooth profile extending fully 360° about the seal, including those areas where bristles are not present. The sealing capacity is not substantially degraded, while affording significant sealing improvements over conventional labyrinth seals. Additionally, when retrofit into labyrinth seals with radial movement, the individual labyrinth seal segments are free to move radially independently of one another during transients.

Abstract: A number of sealing segments 20 mounts a brush seal about a rotor. The tips of the brush seal 46 are maintained out of contact with the rotor surface throughout the entire operating range of the turbomachinery. Thus, the increase in temperature resultant from rubs between the bristle tips and the rotor 12 which effectively increase vibrations of the turbomachinery are eliminated. Brush seals are therefore maintained out of contact with the rotor throughout the entire operating range of the turbomachinery and thus do not affect the dynamic behavior of the rotor.

Abstract: Circumferentially extending sealing segments (45) are disposed about a rotary component (16) and have seal face (34) carrying a plurality of labyrinth seal teeth (36) and a brush seal (37). The segments are movable between large and small clearance positions relative to the rotor at start-up and steady-state operating conditions, respectively. In one form, springs (31) bias the segments radially outwardly at start-up and steam pressure displaces the segments to the small clearance positions at steady-state operations. In a further embodiment, springs bias the segment for movement to the small clearance position, the extent of movement being determined by thermal expansion of centering rings mounting the segments to the stationary components.

Abstract: A self-centering brush seal is disposed in an annular groove formed in a stationary component about a rotatable component, the stationary and rotatable components having a common axis. The brush seal includes a plurality of bristles projecting into sealing engagement with the rotating component. The brush seal has a radial clearance in the groove enabling the brush seal for free-floating radial excursions within the groove to maintain concentricity with the rotary component notwithstanding deviation of the axis of rotation of the rotating component relative to the axis of the fixed component. In another form, the brush seal comprises a plurality of arcuate segments having a helical coil spring biasing the segments for radial movement enabling the tips of the bristles to seal against the rotatable component. In a further embodiment, leaf springs bias each segment to maintain its bristles in engagement with the rotatable component.

Abstract: Brush seals are employed on steam turbine rotors without the risk of causing thermal rotor bowing and without compromising the sealing performance. In one form, a groove in the rotor has an insert in frictional contact with the brush seal. The non-uniform distribution of heat due to frictional contact between the brush seal and proud portions of the rotor is dissipated within the insert such that adjoining rotor portions are substantially uniformly heated without causing thermal bow. In a further form, a groove or grooves are provided in the rotor surface adjacent to the brush seal and maintain non-uniform heat distribution locally in the rotor without causing thermal bow of the rotor. In another form, a land projects radially outwardly of the rotor surface in contact with the brush seal. The non-uniform distribution of heat due to frictional contact between proud portions of the land and the brush seal dissipates into a uniform distribution of heat in the rotor proper to avoid thermal bowing.

Abstract: An imaging apparatus includes a collection of optical elements arranged in a predetermined sequence and cooperable to define a dark-field optical arrangement and a bright-field optical arrangement. The dark-field optical arrangement and a bright-field optical arrangement may be defined along the same or different optical path(s). At least one of the optical elements is operative to enable at least one of the dark field or the bright-field optical arrangements. In a first embodiment said one optical element is movable from a first to a second position to enable either the dark-field or the bright-field optical arrangement. In a second embodiment said one optical element is operable to enable simultaneously both the dark-field and the bright-field optical arrangements. Both opaque objects and phase objects in a fluid stream are able to be detected and quantified.

Abstract: A brush seal includes a plurality of bristles in a circumferential array secured to a fixed component and about a rotary component. The bristles are cantilevered toward the rotary component at an angle to the radii of the rotary component with the bristle tips engaged against the rotary component. The bristles are supported by plates on opposite axial sides of the bristles. The plates have channels for directing fluid under pressure into the channels and against the bristles to deflect or bend the bristles toward the rotary component so that the tips of the bristles bear against the surface of the rotary component, enhancing the seal.