Introduction  Aeration fan is an important equipment in the desulfurization wastewater pretreatment system of thermal power plant. It is generally used as the gas supply source for the aeration device in the aeration tank. Therefore, the reliability of the aeration fan directly affects the stability of the desulfurization wastewater pretreatment system.

  Methods  This paper mainly described the characteristics and process of desulfurization wastewater pretreatment, thoroughly analyzed the common problems existing in the aeration device with a practical case, and finally determined the technical scheme of replacing the aeration device with a reasonably arranged top entry agitator.

  Result  By analyzing the desulfurization wastewater index, sludge deposition and economical efficiency before and after the transformation, it shows that the technical transformation not only can successfully solve the problem of frequent sludge deposition in the aeration tank, reduce the operation and maintenance costs by 85.29% compared with the original aeration device and bring down the auxiliary power cost by 52.78% but also can improve the stability of the desulfurization wastewater pretreatment system operation.

  Conclusion  It has a high reference value for solving the problems existing in the same type of desulfurization wastewater aeration device.