Rotary kiln body and method for reducing NOx of rotary cement kiln by adopting fuel reburning technology

Abstract

The invention discloses a rotary kiln body and a method for reducing NOx of a rotary cement kiln by adopting a fuel reburning technology, the rotary kiln body comprises a rotary kiln body, a primary fuel inlet, a reburning fuel inlet and an over fire air inlet, the primary fuel inlet is a main burner inlet and is arranged at the head of the rotary kiln body, and the reburning fuel inlet is arranged at the tail of the rotary kiln body. The refuel inlet is a first circular ring hole formed in the head of the rotary kiln body along the periphery of the main combustor, and the over fire air inlet is a second circular ring hole formed in the head of the rotary kiln body along the refuel inlet. The method for reducing the NOx of the rotary cement kiln by adopting the rotary kiln body comprises the following steps: S1, introducing the primary fuel with a preset proportion into the primary fuel inlet; s2, reburning fuel with a preset proportion is introduced into a reburning fuel inlet; and S3, over-fire air is introduced from an over-fire air inlet, so that the fuel which is not burnt out in the re-burning area is fully burnt.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a rotary kiln body and a method for reducing NOx in a cement rotary kiln by adopting fuel reburning technology. Background technique [0002] In the process of combustion, NOx is mainly divided into three types: fuel NOx, thermal NOx, and rapid NOx. In the cement rotary kiln burning coal powder, the sources of NOx are mainly fuel NOx and thermal NOx. [0003] The formation of fuel-type NOx is mainly generated by the oxidation of N elements in some nitrogen-containing fuels. Therefore, the formation of fuel-type NOx can be reduced by changing the combustion conditions and using fuels with low nitrogen content. Thermal NOx is produced by the reaction of nitrogen and oxygen in the air when the combustion temperature in the rotary kiln is higher than 1500°C. Therefore, the formation of thermal NOx can be reduced by reducing the combustion temperature, ...

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Problems solved by technology

[0005] Chinese patent application CN104634097A discloses a method and system for reducing nitrogen oxides in a rotary kiln. The main method is to inject a certain amount of combustible gas into the cement rotary kiln through the main burner and burn it together with coal powder. The combustible gas When burning, the oxygen concentration around the pulverized coal is reduced, thereby suppressing the generation of nitrogen oxides in the rotary kiln. However, this method must strictly control the amount of combustible gas introduced, and it cannot exceed the lower explosion limit of the combustible gas, so it has certain advantages. the danger of

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