For a fuel sewage boiler of WNS type related to many cases of failure crack in Anhui Fengyuan Biochemical Co
LTD of Maanshan city
failure process an d reason of this boile was analyzed in this paper based on the theory of heat tr ansfer and boiler inspection. The conclusion shows that the main reasons of fail ure crack were fume tube clogging
higher combustion intensity and imperfect wat er treatment work which can be solved separately by reasonable use