METHOD FOR MODIFYING A TURBINE

1 . A method for modifying a turbine having, arranged in a housing of conical form, rotor blade rings and guide blade rings, the method comprising:

replacing an original rotor blade ring at a first rotor blade position by a replacement rotor blade ring at a second rotor blade position,

while keeping the housing, arranging the second rotor blade position spaced apart from the first rotor blade position along a direction of extent of a rotor shaft of the turbine in the flow direction of a working medium flowing through the turbine,

wherein the replacement rotor blade ring has a larger outer diameter than the original rotor blade ring.

2 . The method as claimed in claim 1 , further comprising:

using a separate component as a positioning element.

3 . The method as claimed in claim 1 , further comprising:

arranging a positioning element designed in the form of a spacer or ring in the rotor shaft for the purpose of fixing the replacement rotor blade ring at the second rotor blade position.

4 . The method as claimed in claim 1 ,

wherein a positioning element is formed integrally on the replacement rotor blade ring.

5 . The method as claimed in claim 4 ,

wherein the positioning element is formed by an extension on a balcony of a root of a replacement rotor blade of the replacement rotor blade ring.

6 . The method as claimed in claim 4 ,

wherein, for the purpose of fixing the replacement rotor blade ring at the second rotor blade position, a shortening of a root of a replacement rotor blade of the replacement rotor blade ring is realized.