Guide vane ring of a turbomachine and associated modification method

A guide vane ring useful in a turbomachine having a casing, the vane ring comprising:

• an annular vane carrier having an inflow-side inlet groove and an outflow-side outlet groove, the vane carrier configured and arranged to be fastened to the casing of the turbomachine;
• a plurality of vanes on the annular vane carrier;
• the inlet and outlet grooves extending in the circumferential direction;
• each of the plurality of vanes having a vane root which has an inflow-side inlet flange and an outflow-side outlet flange;
• the inlet and outlet flanges each extending in the circumferential direction and projecting axially from the respective vane root;
• each vane root inlet flange engaging into the vane carrier inlet groove and each vane root outlet flange engaging into the vane carrier outlet groove;
• one of the inlet and outlet flanges having, both on a front end portion in the circumferential direction and in a rear end portion in the circumferential direction, both radially on the inside and radially on the outside, a contact zone which bears against the vane carrier;
• the other of the inlet and outlet flanges having, on one end portion, radially on the inside, a contact zone which bears against the vane carrier and which is spaced apart from the vane carrier radially on the outside, and having on the other end portion, radially on the outside, a contact zone which bears against the vane carrier and which is spaced apart from the vane carrier radially on the inside;
• the inlet and outlet flanges, between their end portions, being spaced apart from the vane carrier both radially on the inside and radially on the outside.