摘要:
In a steam turbine, a combined brush and labyrinth seal is provided between a diaphragm web and a sealing surface on a rotatable component radially outwardly of the rotor surface. The contact between the brush seal and sealing surface lies along an axially upstream projecting flange of an annular platform such that heat generated by frictional contact between the bristles and the sealing surface has minimal effect on the rotor surface and hence rotor dynamics. A backup labyrinth seal is provided between the web and platform. Additionally, axially upstream projecting flanges are provided on the downstream buckets and which flanges are spaced radially outwardly of the rotor surface and lie in registration with the diaphragm web. Labyrinth teeth seal between the diaphragm web and the bucket flanges serving as a backup seal.
摘要:
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.
摘要:
A labyrinth brush seal combination for a rotating machine comprising an arcuate segment of predetermined axial extent carrying a plurality of axially spaced, circumferentially and radially extending tapered seal teeth, and at least one circumferentially extending array of discrete bristles carried by the segment at a predetermined axial location therealong and projecting beyond the radial extent of the teeth, the bristles having an elongated, flexible carrier strip slidably and removably received within a slot in the segment.
摘要:
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.
摘要:
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.
摘要:
A brush seal, which may be used in gas or steam turbine rotor applications, includes a packet of bristles attached to a seal housing. A seal member is slideably-attached to the seal housing, has a planar first surface portion parallel to, and slideably in contact with, a first surface of the seal housing, and has a planar second surface portion which is parallel to, and slideably in contact with, a first side of the bristle packet. A mechanical spring is positioned in compression between the seal housing and the seal member.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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. In a still further embodiment, the seal segments are pressure balanced in a radial direction with an O-ring seal sealing high and low pressure regions on opposite sides of the segments.