Two-phase supply cyclic semidry process desulfuration method and system

Abstract

The invention discloses a two-phase feeding circulation semidry process desulfurization method and a system thereof. The system comprises a horizontal flue, a reactor, a dust catcher, a draught fan and a chimney which are sequentially connected, and also comprises a conditioning device. The outlet of the lower end of the dust catcher is connected with the conditioning device which is also connected with a dry powder absorbent cabin and a grout slot. The outlet of the conditioning device is connected with the reactor. In the invention, the two-phase feeding mode is used; meanwhile, dry powder absorbent, alkali waste grout, process water, and desulfurization ash are added into the conditioning device to cause that the content of conditioning ash is more uniform, the conditioning ash can be fully dried after entering into the reactor, and does not form scale in the reactor; therefore, the system can steadily run for long period. The alkali waste grout generated in the chemical production can be directly used; the process water consumption is reduced; therefore, the purpose of treatment of wastes with processes of wastes against one another is reduced. The system is suitable for a larger flue gas SO2 by the regulation of the dry powder absorbent, the alkali waste grout, and the process water, increases desulphurization efficiency and enlarges the adaption load range of the flue gas.

Description

【Technical field】 [0001] The invention relates to the field of flue gas desulfurization, in particular to a method and system for circulating semi-dry desulfurization. 【technical background】 [0002] At present, there are two main types of semi-dry desulfurization processes: [0003] One is to make the alkaline absorbent into a slurry with a certain concentration, atomize the slurry into an atomized liquid with a diameter of less than 100μ through a double-flow nozzle or an atomizing turntable, and spray it into the flue gas. With the evaporation of the atomized liquid, the smoke will be reduced. At the same time, the alkaline substance in the slurry absorbs the sulfur dioxide in the flue gas, so that the flue gas is purified [0004] The other is to spray fresh dry powder alkaline absorbent and desulfurization circulating ash directly into the reactor, and spray water into the reactor to reduce the flue gas temperature to obtain better desulfurization conditions, so that t...

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Problems solved by technology

[0005] For the first process, the double-flow nozzle or atomization turntable wears a lot, has a short life, and the atomization effect in the later stage is not good, and the slurry is often bonded to the inner wall of the reactor; temperature control and SO 2 Emission control is limited by slurry preparation, when flue gas temperature or inlet SO 2 When the concentration changes greatly, it cannot desulfurize under the optimal working condition, which has a great impact on the desulfurization efficiency

[0006] The second process directly adds fresh dry powder absorbent and desulfurization circulating ash into the reactor, and sprays clean water into the reactor to cool down, temperature control and SO 2 The emission control is independent of each other, the adaptability to flue gas is greatly improved, the wear of the atomizer is also greatly reduced, and the desulfurization efficiency is greatly improved; however, the mixing effect of water and ash is not good, and the fouling phenomenon in the reactor cannot be fundamentally solved; For example, if the waste alkali slurry (such as calcium carbide slag) produced in chemical production is used for flue gas desulfurization, it is necessary to add a set of drying and pulverizing equipment, which increases investment and production management, so that the use of waste alkali slurry for flue gas desulfurization is limited. limits

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