Ammonia-spraying grid device for SCR-method flue gas denitrification, and SCR-method flue gas denitrification process

Abstract

The invention discloses an ammonia-spraying grid device for SCR-method flue gas denitrification, which comprises an ammonia-spraying grid consisting of bundles of metal pipes, wherein each metal pipe is provided with a nozzle in the radial direction; the nozzle is communicated with the metal pipe; and the included angle between the opening direction of the nozzle and the flow direction of flue gas is between 0 and 90 degrees. The invention also discloses an SCR-method flue gas denitrification process adopting the ammonia-spraying grid device. The process adopts the ammonia-spraying grid to distribute ammonia / air gas mixture sprayed into an inlet flue of a denitrification reactor, and adjusts ammonia spray distribution according to the concentration of NOx in the inlet flue of the reactor so as to mix the NOx in the flue gas with NH3 sprayed in well, thus the mixing effect of the NH3 and the flue gas as well as denitrification efficiency can be effectively improved. A grid-type ammonia spraying-distributing-mixing device of the invention has the advantages of simple structure, low mixture resistance, good distribution effect, insusceptibility to ash deposition, capability of effectively protecting ammonia-spraying grid nozzles from wear, reducing the mixture distance of ammonia and the flue gas in an inlet of the denitrification reactor, improving the utilization rate of denitrification catalysts, reducing the height of the denitrification reactor and reducing the resistance of a flue gas denitrification system, thereby greatly reducing the unit cost of flue gas denitrification.

Description

technical field [0001] The invention relates to an SCR flue gas denitrification process and equipment, in particular to an ammonia injection grid device for SCR flue gas denitrification, which is also applicable to the ammonia injection grid device in flue gas exhausted by various combustion equipment. Background technique [0002] NO x The treatment of air pollution has always been the focus of environmental protection in most countries in the world, and the pollutants it produces are one of the largest pollution sources that cause damage to the ecological environment in our country. At present, it has become the top priority of air pollution control in our country. [0003] for NO x At home and abroad, the selective catalytic reduction (SCR) flue gas denitrification process is mainly used. This process has high denitrification efficiency and no secondary pollution. It is widely used in various combustion equipment. The denitrification principle is the use of NH 3 (Liquid...

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Problems solved by technology

so to NH 3 The mixing with the flue gas has a certain promoting effect, but due to the high speed of the flue gas here, the resistance of the flue gas is also greatly increased

In addition, the ammonia injection grid with holes on the metal tube bundle is used. Due to the poor injection rigidity of the small holes, the mixing effect of the injected ammonia and flue gas is poor, which affects the mixing distance and denitrification efficiency of the ammonia injection grid.

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