Patent ID: 6260269
Filing Date: 2001-07-17
Classification: F01D,Y10T

Abstract:
A method for overhauling a steam turbine to increase its power without increasing its overall length; wherein said steam turbine has a longitudinally-extending shaft, a first existing turbine section, a first bearing, and a first existing seal assembly; wherein said first existing turbine section has a length and a number of stages each having rotatable turbine blades attached to said shaft; wherein said first bearing rotatably supports said shaft; wherein said first existing seal assembly has a longitudinal length, is longitudinally disposed between said first existing turbine section and said first bearing, is radially disposed proximate said shaft, and contains N rows of labyrinth-seal teeth; and wherein said method includes the following steps:a) replacing said first existing seal assembly with a first replacement seal assembly, wherein said first replacement seal assembly contains brush seals and from zero to N minus one rows of labyrinth-seal teeth and wherein said first replacement seal assembly has a longitudinal length which is shorter than said longitudinal length of said first existing seal assembly; andb) replacing said first existing turbine section with a first replacement turbine section, wherein said first replacement turbine section has a length which is longer than said length of said first existing turbine section, wherein said first replacement turbine section has a number of stages which is greater than said number of stages of said first existing turbine section, and wherein the sum of said length of said first replacement turbine section and said longitudinal length of said first replacement seal assembly does not exceed the sum of said length of the first existing turbine section and said longitudinal length of said first existing seal assembly.