The Applied Study On Rotating Coal Classifier In Coal-Fired Power Plants

Coal-Fired Power plants play an important role in our country. Because of the rise of coal consume, the release of SO2 and NOx is gradually increasing, which makes our country environmental quality continually deteriorating. Nowadays, It's main mission to control exhausts from coal-fired.With the attention to protecting environment, the limits to the release of coal-fired power plant are more and more serious. All of the new power plants almost have equipped low NOx burner, the demands of boiler's low NOx burning make temperature of the burner region decreasing. For the steady burning, the fitness regulation of coal powder is improved. So foreign advanced pulverizer systems adopt rotating classifier, which can adapt the fitness of coal powder to variation of load and fuel of the boiler.The equipped coal classifier for MPS-89G middle speed pulverizer in Yangzhou No.2 power plant is static vane classifier, which adjusts the vane angle to regulate the fitness of coal powder. It's difficult to regulate the fitness of coal powder and the regulating range is narrow. So make decisions to implement retrofit for coal classifier.Firstly, the paper thoroughly studies the operation mechanisms and properties of the second DSVSTM dynamic classifier of B&W Company. The analysis shows that this kind of dynamic classifier is typical development direction of coal classifier.Secondly, before retrofit for coal classifier of Yanzhou No.2 power plant, to evaluate and analyze the project of coal classifier in Nanjing thermoelectricity plant, which accumulates experiences for own plant retrofit.Through extensive investigation in crucial technologies, to establish retrofit scheme and study the following main technologies during implementation process:a) The type of dynamic vane impeller configuration of coal classifierb) The material choice and thermal process to keep rotor vane from wearc) Adopt frequency conversion motor to regulate speed of resultant dynamic rotating classifierd) The choice of drive forme) The design of seal and usage of compound wad of seal for resultant dynamic rotating classifierf) The centrifugal force of dynamic vane The result of rotating classifier performance measurement shows that: the...