Ammonia injection grid device for scr flue gas denitrification, and scr flue gas denitrification process

Abstract

The invention discloses an ammonia spraying grid device for SCR flue gas denitrification, comprising an ammonia spraying grid composed of metal tube bundles, each metal tube is provided with a nozzle in the radial direction, and the nozzle communicates with the metal tube; The angle between the opening direction of the nozzle and the flue gas flow direction is 0°-90°. The SCR flue gas denitrification process using the above-mentioned ammonia injection grid device. The invention adopts the ammonia injection grid to distribute the ammonia / air mixed gas injected into the flue at the inlet of the denitrification reactor, and adjusts the injection distribution of ammonia according to the concentration of NOx in the flue at the inlet of the reactor, so that the flue gas The NOx in the gas is fully mixed with the injected NH3, which can effectively improve the mixing effect of NH3 and flue gas and the denitrification reaction efficiency. The grid type ammonia injection distribution mixing device of the present invention has simple structure, low mixing resistance, good distribution effect, is not easy to accumulate dust, can effectively protect the wear of the ammonia injection grid nozzle, and reduce the mixing distance of ammonia and flue gas at the entrance of the denitrification reactor , improve the utilization rate of the denitrification catalyst, reduce the height of the denitrification reactor, and reduce the resistance of the flue gas denitrification system, thereby greatly reducing the unit cost of the 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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