Two stage rotary mixing equipment for ammonia gas and flue gas in SCR (selective catalytic reduction) denitrification system

Abstract

The invention relates to two stage rotary mixing equipment for ammonia gas and flue gas in an SCR denitrification system and belongs to the technical field of flue gas denitrification. The equipment is characterized in that: a smoke box is provided at the straight part of an inlet flue, two opposite sides of the smoke box are open to allow the passage of flue gas flow and communication between the smoke box and the inlet flue, and the rest four sides of the smoke box are engaged with the flue, wherein one side perpendicular to flue gas flow direction is provided with ammonia gas jet pipes; planes of mixing plates arranged in the smoke box are inclined relative to the flue gas flow direction at an angle of 45 degrees and are uniformly arranged at one side of the smoke box; ammonia gas jet orifices are arranged to direct to middle and lower parts of the planes. The beneficial effects of the invention are as follows: flue gas is in a state of two rotary flows after passing through two-stage mixing plates and the two rotary flows orthogonally join with ammonia gas from two-stage ammonia gas jet pipes in the same time, forming a strong fluidic crushing effect; therefore, flue gas and ammonia gas are ideally mixed before flue gas enters into an SCR reactor. The mixing equipment provided in the invention has the advantages of simple construction, fast installation, cheap materials, no need for examination, repair and maintenance, and low comprehensive investment cost.

Description

technical field [0001] The invention belongs to the technical field of flue gas denitration (i.e. NOx removal), and relates to a device for mixing ammonia gas and flue gas in an SCR denitrification system, in particular to a two-stage rotary SCR denitrification system for mixing ammonia gas and flue gas device. Background technique [0002] NOx (nitrogen oxides) is one of the main air pollutants. Most of the nitrogen oxides come from the combustion of fossil fuels and air at high temperatures, including nitrogen monoxide (NO), nitrogen dioxide (NO 2 ) and nitrous oxide (N 2 O), and NxOy. [0003] Because SCR (Selective Catalytic Reduction, Selective Catalytic Reduction, referred to as SCR) denitrification technology has a high denitrification efficiency, most of the power plant flue gas in the world currently adopts the SCR denitrification method, that is, a certain concentration of ammonia (NH 3 ) is sprayed into the flue gas and mixed with the flue gas, and the NH 3 Re...

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Problems solved by technology

Due to the large number of nozzles (thousands of nozzles for 600MW and above generator sets), the operating pressure drop of the system is relatively large, and the nozzles and pipes are often worn and clogged, and the dust in the flue gas is easy to get around the nozzles. As a result, the denitrification performance of the system operation is greatly reduced, and there is a large amount of operation and maintenance costs

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