Empty tower device for controlling high-temperature flue gas by PLC

The utility model belongs to the technical field of comprehensive flue gas treatment, and particularly relates to an empty tower device for controlling high-temperature flue gas by a PLC (ProgrammableLogic Controller), which comprises a first-stage empty tower, a second-stage empty tower and an electric demister which are sequentially connected in series through a flue gas pipeline, the bottoms of the first-stage empty tower and the second-stage empty tower are sequentially connected with a deep cone thickener and a liquid circulating tank in series through connecting pipes respectively, andthe bottom of the deep cone thickener is communicated with a filter press through a connecting pipe; a filtrate outlet of the filter press is communicated with a liquid inlet of the liquid circulatingtank, and a liquid outlet of the liquid circulating tank is respectively communicated with liquid inlets of the spraying devices of the first-stage empty tower and the second-stage empty tower through liquid circulating pipeli