Abstract: A method of fabricating a steam turbine nozzle box is provided, wherein the method includes forming an annular chamber defined by a radially outer wall and a radially inner wall and coupling a plurality of inlets in flow communication with the annular chamber such that steam is discharged from each of the plurality of inlets into the chamber at an oblique discharge angle with respect to an inlet axial centerline.

Abstract: A turbine bucket includes a shank portion, an adjacent and radially inner dovetail mounting portion, an adjacent and radial outer airfoil portion, with a platform at a radially inner end of said airfoil portion adjacent the shank portion, and an integral cover at a radially outer tip of the airfoil portion, wherein the shank portion is shaped to provide a torque zone establishing a desired torque characteristic for the bucket to create, upon insertion into a dovetail groove on a turbine wheel, a desired contact pressure between the integral cover and adjacent covers in a row of similar buckets.

Abstract: A closure bucket group for mounting on a dovetail of a turbine wheel. The closure bucket group may include a leading bucket with a leading bucket rear side, a closure bucket with a closure bucket front side and a closure bucket rear side, and a trailing bucket with a trailing bucket front side. The leading bucket rear side and the closure bucket front side define a first enclosed keyway and the closure bucket rear side and the trailing bucket front side define a second enclosed keyway. A number of keys may be positioned within the first enclosed keyway and the second enclosed keyway so as to support the closure bucket.

Abstract: A method of fabricating a steam turbine nozzle box is provided, wherein the method includes forming an annular chamber defined by a radially outer wall and a radially inner wall and coupling a plurality of inlets in flow communication with the annular chamber such that steam is discharged from each of the plurality of inlets into the chamber at an oblique discharge angle with respect to an inlet axial centerline.

Abstract: Covers on bucket tips are provided with an access slot along a circumferentially facing edge of the cover at a location where moisture removal grooves of the bucket will intersect with the cover. Machine tooling is then applied to form the grooves along the suction side and adjacent the leading of the bucket. The machining runs out through the access slot forming grooves along the side edge of the bucket cover within the slot. The axial extent of the covers overlying leading and trailing edges of the buckets is maintained while enabling moisture removal by centrifugal action.

Abstract: A seal assembly and method for a turbomachine having a rotary member and a stationary member circumscribing the rotary member. The seal assembly comprises an annular-shaped platform on the rotary member so as to be disposed at an outer circumferential region thereof. The platform is supported radially outward from the rotary member so as to project beyond axially-adjacent regions of the rotary member. The platform has a contact region radially separated from the rotary member by a cavity. A sealing member is disposed at a radially inward region of the stationary member, with a portion of the sealing member in rubbing contact with the contact region.

Abstract: Axial entry dovetails on buckets are installed axially into generally complementary-shaped female dovetails about the rim of the turbine wheel. The buckets include bucket covers having an interference fit such that upon installation, the buckets tend to rotate, which causes radial inward displacement of the buckets. To eliminate the bucket rotation and radial displacement, the male dovetails mount an anti-rotation key for reception in a generally complementary-shaped recess at the base of the female dovetail. The anti-rotation key in the slot eliminates rotation and radial displacement of the bucket, maintaining the buckets on radii and enables the bucket covers to be machined to proper diameters.

Abstract: A seal assembly and method for a turbomachine having a rotary member and a stationary member circumscribing the rotary member. The seal assembly comprises an annular-shaped platform on the rotary member so as to be disposed at an outer circumferential region thereof. The platform is supported radially outward from the rotary member so as to project beyond axially-adjacent regions of the rotary member. The platform has a contact region radially separated from the rotary member by a cavity. A sealing member is disposed at a radially inward region of the stationary member, with a portion of the sealing member in rubbing contact with the contact region.

Abstract: In the diaphragm packing area of a steam turbine, a raised platform affords an annular sealing surface for contact with a brush seal carried by the diaphragm. The platform includes a plurality of platform sealing segments secured to a locking device carried by the rotor. The locking device includes a raised rim having flanges with axially oppositely projecting teeth circumferentially spaced one from the other by slots. The platform segments each include a channel section having flanges with axially inwardly directed teeth. By displacing the platform sealing segments radially inwardly and passing the teeth of the locking device and platform segments through the respective slots, the platform segment teeth lie radially inwardly of the locking device teeth. The platform segments are then rotated radially to align the teeth to secure the sealing surface against radial movement. One segment may be staked, welded or screwed to the locking device to preclude circumferential movement during turbine operation.

Abstract: In the diaphragm packing area of a turbine, a raised platform affords an annular sealing surface for contact with a brush seal carried by the diaphragm. The platform includes a plurality of platform sealing segments secured to a locking device carried by the rotor. The locking device includes a pair of raised rims having flanges with teeth projecting axially toward one another and defining slots therebetween. The platform segments each include underlying flanges with axially oppositely directed teeth. By displacing the platform sealing segments radially inwardly and passing the teeth of the locking device and platform segments through the respective slots, the platform segment teeth lie radially inwardly of the locking device teeth. The platform segments are then rotated radially to align the teeth to secure the sealing surface against radial movement. One segment may be staked, welded or screwed to the locking device to preclude circumferential movement during turbine operation.

Abstract: Axial entry dovetails on buckets are installed axially into generally complementary-shaped female dovetails about the rim of the turbine wheel. The buckets include bucket covers having an interference fit such that upon installation, the buckets tend to rotate, which causes radial inward displacement of the buckets. To eliminate the bucket rotation and radial displacement, the male dovetails mount an anti-rotation key for reception in a generally complementary-shaped recess at the base of the female dovetail. The anti-rotation key in the slot eliminates rotation and radial displacement of the bucket, maintaining the buckets on radii and enables the bucket covers to be machined to proper diameters.

Abstract: A first steam turbine of a reaction stage design is retrofitted to form a second turbine of a substantially impulse stage design using common components with the first turbine. To retrofit the new steam path into the first turbine, the upper outer and inner shells and rotor of the first turbine are removed leaving the lower outer shell. A lower carrier section is installed in the lower outer shell. A lower inner shell forming part of the new steam path is installed on the lower carrier ring. The rotor forming part of the new steam path is installed. The upper inner shell is bolted to the lower inner shell encompassing the rotor and an upper carrier section is bolted to the lower carrier section. Finally, the upper outer shell is bolted to the lower outer shell. Consequently a new steam path of reduced diameter is retrofitted into a prior turbine using the prior turbines outer shell.

Abstract: In the diaphragm packing area of a steam turbine, a raised platform affords an annular sealing surface for contact with a brush seal carried by the diaphragm. The platform includes a plurality of platform sealing segments secured to a locking device carried by the rotor. The locking device includes a raised rim having flanges with axially oppositely projecting teeth circumferentially spaced one from the other by slots. The platform segments each include a channel section having flanges with axially inwardly directed teeth. By displacing the platform sealing segments radially inwardly and passing the teeth of the locking device and platform segments through the respective slots, the platform segment teeth lie radially inwardly of the locking device teeth. The platform segments are then rotated radially to align the teeth to secure the sealing surface against radial movement. One segment may be staked, welded or screwed to the locking device to preclude circumferential movement during turbine operation.

Abstract: In the diaphragm packing area of a turbine, a raised platform affords an annular sealing surface for contact with a brush seal carried by the diaphragm. The platform includes a plurality of platform sealing segments secured to a locking device carried by the rotor. The locking device includes a pair of raised rims having flanges with teeth projecting axially toward one another and defining slots therebetween. The platform segments each include underlying flanges with axially oppositely directed teeth. By displacing the platform sealing segments radially inwardly and passing the teeth of the locking device and platform segments through the respective slots, the platform segment teeth lie radially inwardly of the locking device teeth. The platform segments are then rotated radially to align the teeth to secure the sealing surface against radial movement. One segment may be staked, welded or screwed to the locking device to preclude circumferential movement during turbine operation.

Abstract: A first steam turbine of a reaction stage design is retrofitted to form a second turbine of a substantially impulse stage design using common components with the first turbine. To retrofit the new steam path into the first turbine, the upper outer and inner shells and rotor of the first turbine are removed leaving the lower outer shell. A lower carrier section is installed in the lower outer shell. A lower inner shell forming part of the new steam path is installed on the lower carrier ring. The rotor forming part of the new steam path is installed. The upper inner shell is bolted to the lower inner shell encompassing the rotor and an upper carrier section is bolted to the lower carrier section. Finally, the upper outer shell is bolted to the lower outer shell. Consequently a new steam path of reduced diameter is retrofitted into a prior turbine using the prior turbines outer shell.

Abstract: In a steam turbine, a combined brush and labyrinth seal is provided between a diaphragm web and a radially outwardly projecting platform between axially adjacent wheels on the rotor. The brush seal is located upstream of the labyrinth seal teeth. The platform has at least one and preferably a pair of flanges or fins projecting in opposite axial directions adjacent radial outer ends of the platform. Non-uniform heat distribution resulting from the frictional contact between the bristles of the brush seal and a sealing surface on the platform along the rotor surface affecting rotor dynamics is thereby eliminated or minimized.

Abstract: 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.

Abstract: In a steam turbine, a combined brush and labyrinth seal is provided between a diaphragm web and a radially outwardly projecting platform between axially adjacent wheels on the rotor. The brush seal is located upstream of the labyrinth seal teeth. The platform has at least one and preferably a pair of flanges or fins projecting in opposite axial directions adjacent radial outer ends of the platform. Non-uniform heat distribution resulting from the frictional contact between the bristles of the brush seal and a sealing surface on the platform along the rotor surface affecting rotor dynamics is thereby eliminated or minimized.

Abstract: A steam turbine has a rotor mounting axially spaced rotor wheels having male dovetails for mounting a plurality of axially spaced buckets having female dovetails. A plurality of arcuate bridging members extend axially between the axially adjacent bucket dovetails at locations spaced radially outwardly of the surface of the rotor shaft. A diaphragm in radial opposition to the bridging member mounts a brush seal having bristles engaging the bridging member. The bridging member carries backup labyrinth seal teeth for sealing with the diaphragm. The friction generated by contact between the brush seal bristles and bridging members lies radially outwardly of the rotor whereby non-uniform distribution of heat about the rotor surface due to frictional contact with the brush seal is avoided, with consequent avoidance of rotor bowing.

Abstract: A steam turbine has a rotor mounting axially spaced rotor wheels having male dovetails for mounting a plurality of axially spaced buckets having female dovetails. A plurality of arcuate bridging members extend axially between the axially adjacent bucket dovetails at locations spaced radially outwardly of the surface of the rotor shaft. A diaphragm in radial opposition to the bridging member mounts a brush seal having bristles engaging the bridging member. The bridging member carries backup labyrinth seal teeth for sealing with the diaphragm. The friction generated by contact between the brush seal bristles and bridging members lies radially outwardly of the rotor whereby non-uniform distribution of heat about the rotor surface due to frictional contact with the brush seal is avoided, with consequent avoidance of rotor bowing.