Three-step denitrification process of flue gas at the front end of bagasse boiler in sugar factory

Abstract

The invention provides a three-step denitration technology for front-end smoke of a bagasse boiler in a sugarhouse. The three-step denitration technology is characterized by comprising the following steps: (1) recycling combustion of the smoke: flue smoke between a draught fan of a dust collector at a bulged part at the bottom of a hearth and a chimney is used as boiler feeding air and part of bottom primary air and is conveyed back to a main combustion region of the hearth of the boiler; (2) biomass low-NOx mixing combustion is adopted to consume residual oxygen in the boiler smoke to promote NOx reduction; (3) external SNCR denitration: NOx is further reduced by a reducing agent. According to the three-step denitration technology, discharge with standards of the NOx in the smoke from the bagasse boiler in the sugarhouse is realized, and the denitration efficiency can be over 70 percent.

Description

technical field [0001] The patent of the invention relates to a flue gas denitrification process of a combustion boiler, especially a three-step denitrification process of the flue gas at the front end of a bagasse boiler in a sugar factory. Background technique [0002] Nitrogen oxides (NOx) are one of the main pollutants that cause serious air pollution. With the implementation of the new standard "Emission Standards of Air Pollutants for Thermal Power Plants" (GB13223-2011), stricter emission limits are set for the emission concentration of NOx indicators. [0003] Sugar factory boilers mostly use bagasse and eucalyptus bark as fuel, and use scraper-feeder-secondary hot air blowing to enter the furnace for suspension combustion. Suspension combustion needs to deliver a large amount of air to the boiler to make the fuel It can be fully burned in an oxygen-enriched atmosphere, and in a high-temperature environment, it causes excessive emissions of nitrogen oxides in the fl...

AI Technical Summary

Problems solved by technology

This technology is realized by improving the combustion method and process, such as low-nitrogen burner, air staged combustion, fuel staged combustion, flue gas recirculation, etc. It is characterized by low investment and simple process, but the denitrification efficiency is low, and it is also Unable to meet the requirements of emission standards

Terminal denitrification refers to the denitrification of the tail gas discharged from the combustion boiler, and the purification of NOx in it. It is the mainstream technology for denitrification of combustion boilers at present. Large investment costs and high operating costs. For sugar factories with seasonal production, the economic benefits are low, which increases the production cost of sugar factories.

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