TWO-LEVEL STAGE OF TWO-LEVEL LOW PRESSURE CYLINDER Russian patent published in 2017 - IPC F01D9/04 F01D5/14 

FIELD: machine engineering.

SUBSTANCE: two-level stage of the steam turbine contains a two-level nozzle and a two-level impeller wheel. The nozzle unit of the stage is made in the form of a single, non-separable structure with a conical partition, separating the nozzle blades of the upper level from the nozzle blades of the lower level. Chord profiles of the blades in the root sections of the upper level are made at least 30% less than the chords of the profiles in the peripheral sections of the lower level. The blades of the upper level nozzle unit are displaced relative to the blades of the lower level nozzle unit towards the impeller wheel of the two-level stage. There is an aerodynamic filter in front of the upper level nozzle unit consisting of flat radially mounted perforated plates continuously disposed with an angular interval not exceeding 5°. The stage impeller wheel is made of two-level working blades, which have a single, non-separable structure.

EFFECT: increasing the efficiency and reliability.

2 dwg