The W-shaped flame boiler with closed middle storage pulverizing system is designed to burn low volatile lean coal and anthracite. Blending coal with high proportion of bituminous coal is able to improve the adaptability of fuel and the flexibility of the boiler. It is necessary to solve the technical problems such as explosion prevention of the pulverizing system

anti-burning of pulverized coal pipes and prevention of serious slagging in the furnace. Therefore

an inert explosion-proof pulverizing technology

in which low temperature flue gas is used for temperature adjustment

is proposed. This method solves the problem of explosion prevention of coal pulverizing system effectively. By increasing the capacity of cooling air from primary fan to reduce the temperature of hot primary air conveying pulverized coal and the adaptability of the burners to blended bituminous

the safety of the primary air pipes and the burners will be guaranteed. With the optimization of refractory belt arrangement and combustion adjustment

this method not only controls the slagging

but also improves the performance of combustion in the furnace effectively. By these integrated technologies presented above

the goal of co-firing 70% bituminous coal safely and economically in the W-shaped flame boiler with closed ball mill medium storage pulverizing system is achieved.