What type of steam turbine allows for steam admission at two or more different pressure stages?

The mixed-pressure steam turbine is designed to operate with steam admission at two or more different pressure stages. This type of turbine is particularly beneficial in systems where steam is available at varying pressures, allowing for improved efficiency and better utilization of the steam energy available. By utilizing different pressure stages, the turbine can harness energy from the steam more effectively, optimizing performance over a range of operating conditions.

In contrast, a single-pressure steam turbine only uses steam at one pressure level, which limits its flexibility and operational efficiency when varying types of steam are available. Back-pressure steam turbines operate where steam exits the turbine at a pressure suitable for heating applications or other processes, whereas condensing turbines typically operate at lower pressures to condense steam into water, maximizing energy extraction but not allowing for multiple pressures of steam admission.

Thus, the mixed-pressure design enables enhanced performance and efficiency by leveraging diverse steam sources effectively.