RESULTS OF PILOT STUDIES OF A METHOD OF STEAM-GAS CLEANING OF HEATING SURFACES OF A ONCE-THROUGH BOILER FROM IRON OXIDE DEPOSITS
Pilot researches of a method of steam-gas cleaning of operational deposits of internal surfaces of samples from the pipes Ø32x6 (12H1MF) of the lower radiation part of a once-through boiler of supercritical pressure are conducted of steam-gas stream at a temperature of 350÷450 °C. Because of the performed work the technological criteria, allowing counting a mode of steam-gas cleaning are defined. For cleaning of internal surfaces of a once-through boiler pipes from iron oxide deposits in the steam-gas stream it is offered to be used by gaseous reagents gases reducers (carbon oxide and hydrogen), and for the subsequent passivation of the cleared surfaces - oxygen. In the course of researches cleaning of internal surfaces of samples from pipes of a once-through boiler from operational deposits, was carried out by steam-gas mix on the basis of carbon oxide (CO), the water solution of formic acid (HCOOH) received at thermal decomposition. Reactionary ability of steam-gas mix (not less than 40 g/(m 2.h)) provides performance of cleaning of pipes of lower radiation part of a once-through boiler with maximum permissible impurity (250 g/m 2) in 6 hours. The established experimental criteria allow executing calculations of technological parameters of a method of steam-gas cleaning of a once-through boiler.