This invention relates to the field of blade cleaning technology and discloses a blade cleaning device for thermal power turbines, comprising: a support base, a
dry ice insulation hopper on the upper part of the support base, the
dry ice insulation hopper being connected to a Venturi
solid-gas two-phase mixer, the air inlet end of the Venturi
solid-gas two-phase mixer being connected to a high-pressure
air compressor; the
discharge end of the Venturi
solid-gas two-phase mixer being connected to a high-pressure flexible hose, the
discharge end of the high-pressure flexible hose being connected to a
dry ice cleaning gun and a
nozzle; a fixing block being installed at the center of a
valve seat, a through-type material passage chamber being opened at the center of the fixing block; a guide rod being axially arranged at the center of the
valve seat, a first sealing valve core and a second sealing valve core being slidably sleeved on both sides of the guide rod; and a reset element being sleeved at the center of the guide rod. This device forms a bidirectional hard seal when the pipeline pressure fluctuates, blocking the reverse flow of high-pressure
airflow, preventing accelerated sublimation of dry ice particles and
instability in the feeding process, and ensuring the stability of the solid-gas two-phase flow transportation.