Study On Coal Dust Explosion Suppression Technology Of Low Rank Coal Drum Drying

Low rank coal is abundant in our country,because of the low rank coal metamorphic degree,moisture content is higher,and its easy to spontaneous combustion,difficult to store and so on,its industrial utilization value was very limited,therefore,base on its characteristics,the physical methods adopted to carry out dry mass,realize its calorific value is increased significantly,and improve the utilization of coal resources.Technology of coal physical drying quality in modern,the drum drying technology has been relatively mature,and is widely used in high rank coal physics drying.But for the low rank coal,due to large amount of coal dust in drum drying process,when the coal dust reaches the explosion limit concentration and introduce the high temperature flue gas with mars from burner through the wind device to the cylinder,oxygen concentration is sufficient in roller,when three conditions have at the same time,is bound to happen explosion of coal dust.Although several test in lab and engineering practice,but are not greatly reduce coal dust and absolutely eliminate the high temperature flue gas of Mars,so the effective control the oxygen concentration in cylinder within the range of security,is the key to achieve system coal-dust suppression explosion.According to mechanism of coal dust disaster,on the basis of analysis in low rank coal physical and chemical properties,the process of drum drying and assembly.Fluent and the related theory,simulation research on oxygen concentration and precipitation rate of the drum dryer with different inlet flue gas temperature,get the temperature of high temperature flue gas,precipitation rate and the relationship between the oxygen content in drum and its change rule;Developed based on the negative oxygen controlled hot flue gas recycling system.In engineering practice,base on the characteristics of dry material,attached to adjustment of the internal structure of the drum drying machine and optimization of system operation parameters,which can realize the effective control of the oxygen concentration inside the drum,suppression the coal dust explosion.