| 摘要 |
PROBLEM TO BE SOLVED: To improve reliability and the economical efficiency of a heat transfer pipe of a heat recovery type boiler to recover heat from coarse produced gas generated at a coal gasifying furnace by the heat transfer pipe of the heat recovery boiler is formed of a Cr radical alloy steel. SOLUTION: In a coal gasifying device, the surface on the coarse produced gas side of a heat transfer pipe 4 of a heat recovery boiler 1 is formed of a Cr radical alloy steel containing at least 8 wt.% or more (preferably 12 wt. % or more) Cr and steam occupying 20 50 Vol.% of coarse produced gas is fed to the coarse produced gas inlet 2 side of the heat recovery boiler 1. This constitution forms an oxidation film of Cr having corrosion resistance against H2 S on the surface of the heat transfer pipe 4 of the heat recovery boiler 1, containing Cr, through oxidation of steam during the starting of operation of the heat recovery boiler 1, prevents the occurrence of corrosion by using a low-cost material, and improves reliability and the economical efficiency of the heat recovery boiler heat transfer pipe 4. |
