Variable-diameter desulfurizing tower

The invention discloses a variable-diameter desulfurizing tower. The variable-diameter desulfurizing tower comprises an absorbing tower, a demister and a slurry pond, wherein an absorbing tower inlet is arranged in the middle of the absorbing tower, an absorbing tower outlet is arranged at the top of the absorbing tower, five spray layers are arranged above the absorbing tower inlet, and each spray layer is provided with multiple nozzles; the demister is located at the upper part of the absorbing tower and arranged between a fifth spray layer and the absorbing tower outlet, the diameter of the part above the fifth spray layer is larger than that of an absorbing tower body, and the dispersion angle of the part above the fifth spray layer is in a range of 100-107 degrees; the slurry pond is arranged at the lower part of the absorbing tower, the diameter of the lower part of the slurry pond is larger than that of the absorbing tower body, and the contraction angle of the lower part of the slurry pond is in a range of 60-67 degrees. The variable-diameter desulfurizing tower has the benefits as follows: the coverage rate of nozzle slurry is increased by the aid of the five spray layers provided with the multiple nozzles; due to the variable diameter of the part above the spray layers and the variable diameter of the lower part of the slurry pond, the retention time of limestone slurry in the absorbing tower is prolonged, the circulation volume of the slurry is guaranteed, and full contact of the limestone slurry with flue gas is guaranteed.