Device with integral injection system for removing sulfur trioxide and NOx in flue gas

Abstract

The invention relates to a device with an integral injection system for removing sulfur trioxide and NOx in flue gas. The device comprises a boiler, a boiler coal economizer, a flue, an SCR (selectivecatalytic reactor) and the integral injection system. The integral injection system comprises a gas inlet assembly, a first feed assembly, a second feed assembly, a fluidized bed type distribution assembly and an integral injection assembly, the gas inlet assembly is used for providing gaseous media, the first feed assembly is used for adding gaseous reducing agents, the second feed assembly is used for adding alkaline powder absorbents, the fluidized bed type distribution assembly is used for fluidizing the alkaline powder absorbents, and the integral injection assembly is used for sprayingfluidized alkaline powder absorbents and the gaseous reducing agents, which are mixed with one another, into the flue. The device has the advantages that the alkaline powder absorbents can be fluidized and can be mixed with the gaseous reducing agents to be in two-phase mixed states, then the fluidized alkaline powder absorbents and the gaseous reducing agents can be uniformly sprayed into the flue by the integral injection assembly, sufficient reaction can be carried out on the alkaline powder absorbents, the gaseous reducing agents and the flue gas, accordingly, the sulfur trioxide and the NOx in the flue gas can be deeply removed, and the device is applicable to boilers, is excellent in environmental protection and has an excellent economic benefit and a broad application prospect.

Description

technical field [0001] The invention relates to a device for removing sulfur trioxide and NOx in flue gas with an integrated injection system. Background technique [0002] SCR: Selective Catalytic Reduction, referred to as SCR. SCR denitrification technology refers to the reduction agent (such as NH 3 , urea and ammonia water, etc.) under the action of a catalyst, "selectively" react with NOx in the flue gas to generate non-polluting N 2 and H 2 O's NOx emission reduction technology. [0003] In order to control NOx and SO emissions from coal-fired boiler flue gas 3 Pollutants, currently the main methods are ammonia reduction SCR denitrification and base absorption deSO 3 technology. During the application of these devices, the following problems were mainly encountered: [0004] Ammonia reduction SCR denitrification: SCR denitrification injects ammonia gas into the flue gas through the ammonia injection grid AIG, and reduces NO to nitrogen and water under the action...

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Problems solved by technology

The existing technology "A device for removing sulfur trioxide in flue gas by lye spray atomization" (application number: 201610384872.1) combines a two-fluid atomizing spray gun with a spoiler, and arranges multiple spray guns on the flue section to The lye is atomized and injected into the flue gas. For units whose flue gas flow field distribution and law change greatly with the load, the adaptability of the injection device is low; the prior art "a device for removing sulfur trioxide from boiler flue gas" (Application No.: 201710099614.3) is connected to multiple branch pipes by spraying the main pipe, and each branch pipe is equipped with multiple flow equalizing nozzles to spray the alkali powder into the flue gas by pneumatic conveying, but it is impossible to realize the connection between the branch pipes and the nozzles on the branch pipes. Uniformity of base absorbent injection volume among

[0006] In the flue gas emission device of coal-fired boiler, if SCR denitrification and SO 3 Each removal device is equipped with a set of absorbent injection system, which increases the complexity of the equipment system of the unit, and the two sets of injection devices have the problem of mixing uniformity of absorbent and flue gas

For the above-mentioned process gas carrying solid particles and NH 3 The problem of uneven distribution of mixing with flue gas, drawing on the liquid characteristics of fluidized gas-solid multiphase flow ( figure 1 ), the present invention proposes a system device with a uniform distribution of gas-solid multiphase flow

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