Pulverized Coal Reburning Powder Separation Technology To Reduce Nox Emissions

NOx that produced during the process of the burning of the coal is not only do harm to the health of the people, but also pollute the environment badly. In our country coal combustion of power plant boilers is a major anthropogenic source of nitrogen oxides. If efficient measures are not taken to reduce the NOx emission from power plant, the living space for human being will become worse .Micro-pulverized coals are excellent reburning fuel to a high degree reducing of the NOx emission. In the storage milling system, there're a lot of micro-pulverized coals among the coals have grinded, so the method to separate them is studied in this paper.The paper consists of following parts:Firstly, research the method of separating micro-pulverized coals from the tertiary air. For the low efficiency of the perfect pulverized coal classifier, there're a lot of micro-pulverized coals in the tertiary air. those coals can be separated by MDC bag remover and wide-space ESP. The method is simple and mature in technology.Secondly, the method of separating coals by swirling vane, because the small centrifugal force in the perfect pulverized coal classifier. Micro-pulverized coals can't be separated. With high-speed swirling vane , the micro-pulverized coals can be separated.Thirdly, research the method of extracting the micro-pulverized coals from the perfect pulverized coal classifier. The result justify that extracting some air can not only improve the efficiency of the perfect pulverized coal classifier, but also can extract enough micro-pulverized coals.At last, numerical simulation on extracting air from the perfect pulverized coal classifier. Models established by using fluent software simulate the flow field and granularity field, the filed proved the scientific of extracting air from the perfect pulverized coal classifier to get micro-pulverized coals.