The desulfurization efficiency of the unit firing high sulfur content coal can only reach 90% to95%.To satisfy the novel flue gas emission standard

the limestone-gypsum desulfurization double-tower series system is gradually adopted.The development process of the limestone-gypsum desulfurization technology is overviewed

and the desulfurization double-tower series system's characteristics that are different with the desulfurization single tower's are summarized.The influence of several factors on the design and operation of the desulfurization double-tower series system is analyzed

such as the pH value

first tower efficiency

flue gas velocity

liquid gas ratio and the volume of slurry tank.Finally

some suggestions are put forward

like selecting the fist tower efficiency as 70% to 80% when the boiler firing high sulfur content coal

and 80%to 80% when the boiler firing medium and high sulfur content coal.It suggests the flue gas velocity for the first tower be set as 4.0m/s to 4.5m/s

that for the second tower be set below 3.6m/s.The pH value should be considered when choosing the gas-liquid ratio for the two towers.The gas-liquid ratio for the second tower is better not be too high

5L/m3 to 10L/m3 is reasonable.