Ammonia spraying and mixing system for coal-fired flue gas SCR denitration technology

Abstract

The invention discloses an ammonia spraying and mixing system for the coal-fired flue gas SCR denitration technology and relates to a system used for spraying reducing agent ammonia and strengthening the mixture of ammonia and flue gas. The ammonia spraying and mixing system comprises 5-20 reducing agent ammonia jet tubes with independent flow control systems and longitudinal vortex generation elements, wherein the tail end of each reducing agent ammonia jet tube is provided with a two-way nozzle which is vertical and symmetric to the flue gas stream, each longitudinal vortex generation element is a triangle, a trapezoid, a half round or a half ellipse, each longitudinal vortex generation element is connected with the flue wall and forms 30-60 degrees angle with the flue gas stream so as to form longitudinal vortex of which downstream is stable, increase the intensity of turbulent flow and enhance the mixture of reducing agent ammonia and glue gas. The device has the following advantages: 1) the stable longitudinal vortex is formed, the mixing intensity of vortex is increased, and the mixing effect of ammonia and nitrogen is optimized; 2) the number of the ammonia jet tubes is reduced, the ammonia-spraying regulation difficulty is lowered; and 3) pressure breakdown caused by the system is relatively small and the energy loss is reduced.

Description

technical field [0001] The invention relates to environmental protection technology, in particular to an ammonia injection mixing system equipped with coal-fired flue gas SCR denitrification technology. Background technique [0002] In today's society, the emission of nitrogen oxides will cause a series of problems such as ozone layer destruction, acid rain and atmospheric smoke formation, which will cause serious harm to human health. From a global perspective, the nitrogen oxides produced by fuel combustion, especially coal combustion, are one of the main sources of nitrogen oxides in the atmosphere. Among many denitrification technologies, selective catalytic reduction (SCR) denitrification technology has been widely used commercially due to its simple device structure, no by-products, convenient operation, high reliability, and high denitrification efficiency. Its main principle is to spray the reducing agent ammonia into the flue gas at 280°C to 420°C and mix it evenly...

AI Technical Summary

Problems solved by technology

At present, in commercial application, the ammonia injection device in the form of a grid is generally used. The ammonia injection grid method adopts multi-point injection zone adjustment. Due to the large number of reductant ammonia injection pipes and nozzle holes, it makes its It is quite difficult to adjust in actual operation. The static mixer that must be installed in order to improve the mixing effect and shorten the mixing distance often increases the installation cost and increases the pressure drop of the system and does not reduce the adjustment difficulty of ammonia injection during operation.

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