Method for controlling crystalline products in wet flue gas desulfurization slurry pool

Abstract

A method for controlling the crystalline products in a wet flue gas desulfurization slurry pool belongs to the technical field of flue gas desulfurization. The method comprises the following steps thaA method for controlling the crystalline products in a wet flue gas desulfurization slurry pool belongs to the technical field of flue gas desulfurization. The method comprises the following steps thaver high saturation of calcium sulfite in the liquid phase for synchronizing the yield and growth of gypsum crystal in the slurry, to prevent excessive production of gypsum fine crystal and to facilitver high saturation of calcium sulfite in the liquid phase for synchronizing the yield and growth of gypsum crystal in the slurry, to prevent excessive production of gypsum fine crystal and to facilitate the dehydration of the crystalline products.ate the dehydration of the crystalline products.t: for an absorber which has a flue gas purification channel on top, a raw flue gas inlet in the middle and a slurry pool at bottom, the saturation of calcium sulfite in a liquid phase in the slurry pt: for an absorber which has a flue gas purification channel on top, a raw flue gas inlet in the middle and a slurry pool at bottom, the saturation of calcium sulfite in a liquid phase in the slurry pool can be quickly reduced by controlling the required volume of injected oxygen in the slurry pool and the oxygen supply is kept constantly in a proper state to prevent semi-hydrated gypsum and crystool can be quickly reduced by controlling the required volume of injected oxygen in the slurry pool and the oxygen supply is kept constantly in a proper state to prevent semi-hydrated gypsum and crystal scale generated due to inadequate filling of oxygen in the slurry pool from causing scale to block the vessel wall and pipe wall of the slurry pool and to provent the crystalline products from dehyal scale generated due to inadequate filling of oxygen in the slurry pool from causing scale to block the vessel wall and pipe wall of the slurry pool and to provent the crystalline products from dehydrating difficultly; the injection amount of the limestone slurry in the slurry pool is controlled to control the fluctuation range of the pH value of the gypsum slurry in the slurry pool to prevent odrating difficultly; the injection amount of the limestone slurry in the slurry pool is controlled to control the fluctuation range of the pH value of the gypsum slurry in the slurry pool to prevent o

Description

technical field [0001] The invention relates to a method for controlling the crystallization products in the slurry tank of the limestone-lime / gypsum wet flue gas desulfurization absorber, and further refers to controlling the liquid phase calcium sulfite concentration in the slurry tank and the liquid phase crystallization conversion conditions so that the crystallization is formed along the target product And make the generated crystalline target product particles as large as possible to facilitate the dehydration of the crystalline product. Background technique [0002] my country is a big country in energy production and consumption. In the primary energy consumption structure, coal accounts for more than 60%, occupying an absolute dominant position. The average sulfur content of coal in my country exceeds 1%, and sulfur dioxide is produced during coal combustion. As the amount of coal burned increases year by year, the amount of sulfur dioxide emissions increases accord...

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Problems solved by technology

[0003] The previously built limestone-lime / gypsum wet flue gas desulfurization device has never implemented effective control on the crystallization products of the slurry tank, which is manifested in the slurry tank and slurry pipelines are prone to scaling (crystal scale), and the scale is dense and hard. It will cause blockage of containers and pipelines, and in serious cases, all slurry pipelines will be blocked, forcing the flue gas desulfurization device to stop operating

Not only that, but also because the generated crystalline products cannot be properly controlled, more hemihydrate gypsum is mixed into the dihydrate gypsum in the generated crystals, and because the crystal particles of hemihydrate gypsum are smaller than the dihydrate gypsum, they will be blocked when the slurry is filtered The filter holes make it difficult to dehydrate the crystallized product, and the phenomenon of "looseness" often occurs when the slurry is filtered

The occurrence of the above-mentioned situation makes the desulfurization devices that have been built start and stop. On the one hand, the operation rate of the desulfurization devices is reduced, so that the devices that have been built cannot play their due effects; on the other hand, enterprises have to spend a lot of energy Manual descaling and treatment of filtered slurry gypsum, resulting in an increase in the operating cost of the flue gas desulfurization unit

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