Large steam turbine free-standing blade development based on 30 years of experience

The design of free-standing turbine blades has been evolving for 30 years. Presently, free-standing blades are used in low-pressure turbines operating at design pressures up to 36 psia, i.e., generally in the last 3 or 4 LP turbine stages. The design requirements for free-standing LP turbine blades, the facilities and equipment used to test experimental designs, and the performance characteristics of forged steel or titanium alloy blades, ranging in length from 9 to 54 in., are discussed. (LCL)