Nozzle Set

a component of a steam or gas turbine consisting of shaped nozzle (guide) blades placed around the turbine’s periphery. In the channels between the blades, the steam (or gas) expands, and its potential energy is converted into kinetic energy. The blades of the nozzle set are either secured to stationary disks (diaphragms) or mounted directly in the turbine’s casing. The steam in a nozzle box acquires considerable velocity; it then flows through the turbine’s rotor blades, where the kinetic energy of the steam jet is converted into mechanical energy of the turning rotor. Depending on the steam velocity at the output of the nozzle set, distinctions are made between supersonic and subsonic sets.