Abstract: A flue gas treatment device is provided. A wet electrostatic precipitator and a flue gas heater are integrated in an integrated flue housing of the flue gas treatment device, thus the occupied area of the flue gas treatment device is smaller than that of the solution with devices being arranged separately. Furthermore, since a bidirectional transition flue is not required to be arranged in the integrated flue housing, the flue gas has a good flow uniformity, and further it is not required to arrange a flow equalization orifice plate in the flue, thus the flue gas has a small resistance, thereby reducing the power consumption of the draught fan and increasing the efficiency of the power plant.

Abstract: The invention provides a vacuum dehydrating system for gypsum slurry, comprising a vacuum dehydrating apparatus, a first water supply apparatus for supplying filter cake washing water to the vacuum dehydrating apparatus, and a water heating apparatus for heating the filter cake washing water. The invention also provides a vacuum dehydrating method, comprising the following steps: 1) heating the filter cake washing water by the water heating apparatus; 2) supplying the heated filter cake washing water to a vacuum dehydrating apparatus during dehydrating the gypsum slurry by the vacuum dehydrating apparatus. In the invention, the filter cake washing water is heated. Due to the higher temperature of filter cake washing water, the dehydration rate of gypsum slurry is improved so that water content of gypsum filter cake after dehydration is decreased.