Device and method for removing ammonia from boiler fly ash

Abstract

The invention relates to a device and method for removing ammonia from boiler fly ash. The device comprises an ammonia-containing fly ash storage tank, a stirrer, an alkaline additive storage tank, aspray liquid storage tank, an evaporator, a first gas-solid separator, a second gas-solid separator, an ammonia storage tank and a fly ash storage tank. The method comprises the steps: ammonia-containing fly ash, an alkaline additive and water are mixed and stirred, wherein the mass of the alkaline additive and the mass of the water account for 1-2% of the mass of the ammonia-containing fly ash, after stirring, an ammonia initial extraction object and a fly ash initial extraction object are obtained, ammonia and part of fly ash in the ammonia initial extraction object are separated, and thus the ammonia is obtained; and water in the fly ash initial extraction object is evaporated to dryness, then fly ash and air in the fly ash initial extraction object are separated, and thus fly ash is obtained. The ammonia and the fly ash in the boiler fly ash are separated, thus the fly ash meeting the industrial application requirements can be obtained, the separated ammonia is recycled to be secondarily utilized, energy saving and environmental protection are achieved, the structure is simple, the cost is low, using and maintenance are convenient, and wide practicality is achieved.

Description

technical field [0001] The invention relates to the field of pollutant treatment, in particular to a device and method for removing ammonia in boiler fly ash. Background technique [0002] NO x It is one of the main pollutants in the atmospheric environment. Under the requirements of relevant laws and regulations, my country's coal-fired power stations have gradually completed denitrification transformation, and the most widely used denitrification equipment after combustion is SCR technology. Selective Catalytic Reduction (SCR) technology is currently the most efficient, mature and widely used power plant flue gas denitrification technology. SCR denitrification technology uses ammonia as a reducing agent to reduce NO x , limited by chemical principles, catalyst performance and flow field of SCR equipment, ammonia cannot be fully reacted, and the remaining ammonia escapes as ammonia. Domestic and foreign studies have shown that ammonia escape will not only block the air p...

AI Technical Summary

Problems solved by technology

At present, the treatment process is mainly a heat treatment method, that is, the ammonia is volatilized and released from the fly ash by high-temperature heating. This treatment method requires a lot of energy consumption, and the high-temperature process may also cause the decomposition of ammonia to produce NO x new pollutants

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