Selective catalytic reduction device by directly spraying urea solution and method thereof

A selective, urea technology, applied in chemical instruments and methods, separation methods, ammonia preparation/separation, etc., can solve problems such as large space, increase investment and occupation of subsequent equipment, reduce investment and operating costs, and save equipment. Space, use safe and reliable effect

CN102210974AInactive Publication Date: 2011-10-12TONGFANG ENVIRONMENT
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2011-10-12
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a selective catalytic reduction device by directly spraying a urea solution and a method thereof, and relates to the technical field of environmental protection. The device comprises a plurality of groups of spray guns for spraying the urea solution, which are arranged at an inlet flue before a selective catalytic reduction (SCR) reactor, and a mixer and a catalyst which are arranged along the flowing direction of flue gas in turn, wherein each spray gun is connected with a urea solution tank through a metering distributor. Compared with the prior art, the invention has the advantages that: the urea solution is directly sprayed into the flue to thermally decompose the supplied ammonia, the operating cost and equipment investment are reduced, the space is saved, and the device is safe and reliable to use.
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Description

technical field

[0001] The invention relates to the technical field of environmental protection, in particular to a selective catalytic reduction device for directly injecting urea solution and a method thereof. Background technique

[0002] The flue gas produced by fossil fuel combustion contains a large amount of nitrogen oxides. As an acidic gas, nitrogen oxides are one of the air pollutants that form acid rain and acid fog, and have great harm to the ecological environment and human health. Under certain conditions, the nitrogen oxides in the flue gas can undergo a reduction reaction with a nitrogen-containing reducing agent to generate water and nitrogen that will not cause secondary pollution to the environment. This reduction reaction can occur at a relatively low temperature, but it needs the catalytic action of a catalyst to react. This process is called selective catalytic reduction technology SCR. At present, SCR flue gas denitrification technology has been widely...

Examples

Embodiment Construction

[0019] refer to figure 1 , the present invention includes multiple groups of spray guns 2 for spraying urea solution arranged at the front inlet flue of the SCR reactor, and a mixer 4 and a catalyst 5 arranged in sequence along the flue gas flow direction. Each spray gun 2 is arranged on the flue wall or in the flue cavity, and each spray gun 2 is connected with a solution tank 3 containing urea through a metering distributor. The number of mixers 4 is one or more, and a certain distance should be kept between two or more mixers 4 .

[0020] see figure 2 , the method step when the device of the present invention denitrates is:

[0021] 1) Arrange a certain number of spray guns 2 on the flue wall or in the flue cavity in front of the SCR reactor, where the temperature of the flue gas 1 is above 250°C. According to the mol ratio of 1:10~10:1 in the urea solution and the nitrogen oxides in the flue gas, the urea solution of 5%-70% concentration in the solution tank 3 is deliv...