Circulating fluidized bed boiler flue gas desulfurizing system and treatment method thereof

Abstract

The invention provides a circulating fluidized bed boiler flue gas desulfurizing system and a treatment method thereof. The system comprises a circulating fluidized bed boiler and a desulfurizing fluidized bed. A flue gas outlet of the circulating fluidized bed boiler is connected with a gas inlet formed in the bottom of the desulfurizing fluidized bed, and the bottom of the desulfurizing fluidized bed is provided with a desulfurizer inlet. The system is provided with the desulfurizing fluidized bed behind the circulating fluidized bed boiler, a sulfur fixation reaction is transferred to the region with the stable and proper temperature, the influences of temperature changes and atmosphere in the hearth on sulfur fixation reactions and products thereof are eliminated, and by arranging a separator and a return feeder, the desulfurizer is recycled; the accumulation effect in the circulating process is used for enhancing the sulfur fixation reaction, the desulfurizing cost is lowered, andthe desulfurizer utilization rate and desulfurizing efficiency are improved.

Description

technical field [0001] The invention belongs to the technical field of flue gas purification, and relates to a circulating fluidized bed boiler flue gas desulfurization system and a treatment method thereof. Background technique [0002] SO 2 As one of the most important pollutants in the flue gas emitted by circulating fluidized bed (CFB) boilers in coal-fired power plants, its emissions are strictly limited. Desulfurization, thereby reducing environmental pollution. [0003] CFB boilers are usually desulfurized by adding limestone and other desulfurizers to the boiler for flue gas desulfurization. It is a recognized clean combustion technology and has been widely used for its high desulfurization efficiency, low cost, simple operation, and no water pollution. application. The bed temperature of the CFB boiler is uniform and low, generally between 850°C and 900°C. This temperature is just the optimum temperature for the sulfur fixation reaction. At the same time, the gas...

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Problems solved by technology

[0004] CN 103272475 A discloses a desulfurization system for a circulating fluidized bed boiler, in which the upper part of the cyclone separator is connected to the upper part of the furnace of the boiler, and the lower part of the cyclone separator is connected to the lower part of the furnace through a return pipe , there is a desulfurizer inlet on the return pipe, and the inlet is located at the negative pressure position of the return pipe, but the calcium spraying desulfurization technology in the furnace also has some defects in practical application, such as the actual operating bed temperature deviates from the design value, higher than the desulfurization The optimum temperature range is 850°C to 900°C; the dense-phase region at the bottom of the circulating fluidized bed is in a state of constant alternation of oxidation / reduction atmosphere, but most of the time it is in a reducing atmosphere, while in a reducing atmosphere CaSO 4 Easy to decompose, etc.

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