Denitrification method using decomposing furnace and decomposing furnace

Abstract

The invention relates to a denitration method using a decomposing furnace and the decomposing furnace. The method comprises the following steps: coal powder is injected from the lower end of the decomposing furnace and combusted under an anoxic condition to form an anoxic reducing atmosphere, and coal powder is injected from the upper end of the decomposing furnace and combusted to consume part ofoxygen at the upper end of a reducing atmosphere; tertiary air is sprayed into the decomposing furnace in streams to make the air excess coefficient be 0.3-0.6; a cement raw material is respectivelyput into the decomposing furnace from a plurality of feeding ports for carbonate decomposition, so that the temperature at the reducing atmosphere is 900-1100 DEG C; exhaust gas is introduce from thatbottom end of the decomposing furnace for reduction denitration, and the reaction time is 0.5 to 1.2 seconds; and insufficiently combustible solid materials are guided to the decomposing furnace by refluxing with a reflux ratio of 20-45%. The denitration method using the decomposing furnace is simple and easy to operate, can reduce 60-85% of nitrogen oxides generated by a rotary kiln to nitrogen,has high reduction efficiency, effectively reduces the harm to the natural environment, does not affect the decomposition of carbonate in cement raw materials, can fully utilize materials, and savescost.

Description

Technical field [0001] The invention relates to the field of cement industry, and in particular to a method for denitrification using a calciner and a calciner. Background technique [0002] Decomposing furnace is a very frequently used equipment in the cement industry. Currently, there are various types of decomposition furnaces, such as spraying type, swirling type, swirling-spraying type, pipeline suspension type, etc., to cooperate with various decomposition There are also many methods for decomposing the raw cement material used in the furnace. In the process of preparing cement raw meal by rotary kiln, a large amount of exhaust gas containing nitrogen oxides will be discharged. Nitrogen oxides are extremely harmful to the natural environment. It needs to be reduced to nitrogen to reduce the harm. In order to meet this demand, Most of the decomposition furnaces have the function of reducing nitrogen oxides, but the denitration effect of the existing denitrification furnaces...

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Problems solved by technology

During the process of preparing cement raw meal by using the rotary kiln, a large amount of waste gas containing nitrogen oxides will be discharged. Nitrogen oxides are extremely harmful to the natural environment. It needs to be reduced to nitrogen to reduce the hazards. In order to meet this demand, it has been Most of the calciners have the function of reducing nitrogen oxides, but the denitrification effect of the existing calciner denitrification methods and the supporting calciner is not ideal, and the equipment is too complicated, there is a risk of crusting and material accumulation, and the operation is inconvenient At the same time, the energy consumption is high and the cost is high. Therefore, it is necessary to propose an efficient and easy method for denitrification using a calciner, and a calciner suitable for this method

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