Reducing agent injection mechanism suitable for SCR reactor

Abstract

The invention provides a reducing agent injection mechanism suitable for an SCR reactor. The reducing agent injection mechanism comprises a main feeding tube and a plurality of distributing tubes, wherein one end of the distributing tube is communicated with the main feeding tubes; the distributing tubes are provided with flow meters and control valves; the lower surface of each distributing tubeis provided with a plurality of nozzles; the lower part of the nozzle is correspondingly provided with a guide plate consisting of a plurality of static mixing vanes; the nozzle is horn-shaped to reduce injecting resistance of ammonia; the external side surface of the nozzle is symmetrically provided with drainage holes to introduce part of smoke while injecting the ammonia so as to strengthen the mixing effect of NH3 and the smoke; and the lower part of the nozzle is correspondingly provided with an injection tube which serves as a large-throat Venturi tube to form secondary drainage. The reducing agent injection mechanism has the advantages of reducing the using amount of the nozzle and the guide plate, reducing equipment manufacturing cost, improving the mixing effect of the reducing agent and the nitrogen oxide in the smoke and laying a solid foundation for removing the nitrogen oxide from the smoke, along with reasonable structure.

Description

technical field [0001] The invention relates to a flue gas purification device, in particular to a reducing agent injection mechanism suitable for an SCR reactor. Background technique [0002] Selective catalytic reduction (SCR) technology was applied in industrial boilers and power plant boilers in the 1970s. Due to its mature technology and high denitrification rate, it has become the mainstream technology for international flue gas denitrification. The principle is to convert nitrogen oxides (NO X ) into nitrogen (N 2 ) and water (H 2 O). [0003] The SCR reactors are all equipped with a set of ammonia injection mixing mechanism to inject ammonia gas as a catalyst, and make the ammonia gas injected into the flue mix with the NO in the flue gas before entering the SCR reactor body. X Achieve the best turbulent mixing and make the catalyst work evenly. Therefore, NH 3 and NO X The degree of mixing has a great influence on the denitrification efficiency of SCR. If NH...

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Problems solved by technology

However, because the existing nozzle is only a short tube, the injection effect is limited, the mixing distance between ammonia and flue gas is long, and the dust is easy to block the nozzle, so the number of nozzles and deflectors is large, which not only takes up equipment Due to the limited installation space, the pressure loss of the injection mixing system is large, and the system adjustment is complicated. NH 3 NO X The uniformity of mixing is not guaranteed, and the manufacturing cost is high

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