Air-coal graded low-nitrogen combustion equipment and technology and cement clinker firing system

Abstract

The invention relates to air, coal and material graded low-nitrogen combustion equipment and process as well as a cement clinker sintering system. The air, coal and material graded low-nitrogen combustion equipment comprises a decomposition furnace, a tertiary air valve, a cyclone barrel, a rotary kiln and an overturning valve, and is characterized by further comprising a high-temperature-resisting air locking spiral conveyor, a Roots blower, an additionally-arranged tertiary air valve and a material distribution valve, wherein the decomposition furnace is provided with a tertiary air inlet and a separated new tertiary air inlet; a tertiary air general pipeline is connected with the tertiary air inlet of the decomposition furnace through the tertiary air valve; a tertiary air branch pipeline is arranged on the tertiary air general pipeline passing through the tertiary air valve; the additionally-arranged tertiary air valve is arranged on the tertiary air branch pipeline; the tertiary air branch pipeline is connected with the separated new tertiary air inlet through the additionally-arranged tertiary air valve; a region between the lower end face of a cone body of the decomposition furnace and the lower edge of the tertiary air inlet is a reduction decomposition region; and a region between the lower edge of the tertiary air inlet and the lower edge of the separated new tertiary air inlet is a reduction inhibition region.

Description

technical field [0001] The invention belongs to the technical field of cement production in the building material industry, and in particular relates to classified low-nitrogen combustion equipment and technology for wind-coal materials and a cement clinker burning system. Background technique [0002] In response to global climate change, my country has issued GB4915-2013 "Emission Standards of Air Pollutants for the Cement Industry", which requires cement enterprises to x ) emission standard is lower than 400mg / Nm 3 , key areas NO x Emission control at 320mg / Nm 3 within. After the new standard was formulated, due to the NO x The content is 800-1600mg / Nm 3 , the result of its low-nitrogen combustion technology has not yet reached the new standard, therefore, a subsequent treatment method that consumes a large amount of ammonia water has to be adopted to reduce NO x emissions, that is, ammonia denitrification technology (that is, the widely used SNCR method). The disa...

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Problems solved by technology

The disadvantage of the SNCR method is that it significantly increases the operating cost of the enterprise (about 5 yuan / ton of clinker), and there are inevitably ammonia escape and ammonia volatilization problems, and ammonia volatilization will produce flammable, explosive and toxic gas, the corresponding safety management costs will also increase. In addition, the energy consumption and pollution emissions in the ammonia water manufacturing process are also transferred to the cement production process.

Air staged combustion technology NO x The reduction efficiency is only 15-25%, which is greatly affected by the operation control

Fuel Staged Combustion Technology NO x The reduction efficiency is only 15-30%, and there is also the problem of sticky materials on the calciner cone and the side wall of the smoke chamber, which leads to the failure of continuous normal production

NO of air staged combustion technology and fuel staged combustion technology x The reduction efficiency is low, and it is necessary to combine SNCR technology to improve NO x Reduction efficiency, therefore, cannot significantly reduce the amount of ammonia used in SNCR technology

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