Wet desulfurization flue gas bleaching device and bleaching method

Abstract

The invention provides a wet desulfurization flue gas bleaching device and bleaching method. The device has the overall structure including three parts: a flue gas desulfurization part, a desulfurization slurry cooling part and a cooling water heat-dissipation part. The desulfurization slurry cooling part is composed of a multi-stage evaporator, a multi-stage condenser and a multi-stage steam pipeand specifically includes a water intake pipe, a water intake pump, the multi-stage evaporator, a water outlet pump, a steam pipe, the multi-stage condenser, a condensate water outlet and a vacuum gas-extraction port. Desulphurization slurry in a desulphurization slurry buffer zone enters the multi-stage evaporator through the water intake pump and the water intake pipe; the desulphurization slurry flows from top to bottom in the multi-stage evaporator and is flash-evaporated step by step; steam generated by each-stage evaporation flows into the multi-stage condenser from the steam pipe; thetemperature of the desulphurization slurry decreases after multi-stage evaporation, and the low-temperature desulphurization slurry returns to the desulfurization tower through the water outlet pump,steam condensate water is reused for scrubbing a desulfurization tower mist eliminator, and non-condensable gas is discharged from the vacuum gas-extraction port and sent to the desulfurization tower.

Description

Technical field [0001] The invention relates to flue gas dehumidification technology, in particular to a wet desulfurization flue gas de-whitening device and a de-whitening method. Background technique [0002] The wet flue gas desulfurization process uses limestone (CaCO3), lime (CaO) or sodium carbonate (Na2CO3) slurry as a detergent to wash the flue gas in the reaction tower to remove SO2 in the flue gas. This process has a history of 50 years. After continuous improvement and perfection, the technology is relatively mature, and it has high desulfurization efficiency (90% to 98%), large unit capacity, strong coal type adaptability, and low operating cost. Advantages such as easy recycling of by-products. In China's thermal power plants and steel plants, more than 90% of them use wet lime / limestone-gypsum flue gas desulfurization process. [0003] In the wet process, the problem of flue gas reheating directly affects the investment of the entire process. Because the flue gas a...

AI Technical Summary

Problems solved by technology

The first method has been widely used, but due to the poor heat exchange effect of the gas, the heat exchanger is bulky, severely corroded, high in cost, and high in maintenance costs; the second method is simple and low in cost, but it is used for desulfurization Slurry heat exchangers will soon be corroded, clogged, unstable in operation, and high in maintenance costs

This method has a small amount of evaporation, which can easily lead to swelling pools in the desulfurization slurry buffer area of ​​the desulfurization tower.

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