Wall flow and bias flow due to structural irregularities. After being used in paraformaldehyde and formaldehyde distillation columns, ceramic corrugated packing obviously has the function of increasing income and increasing efficiency. Due to its regular shape and regular pores, ceramic structured packing has the characteristics of regular and uniform, large specific surface area, low resistance, uniform distribution and high mass transfer efficiency. It has tackled bulk ceramic Raschig rings, ceramic saddle rings and ceramic step rings. In a formaldehyde distillation column, this material is corrosive because it contains formic acid. In the past, corrosion occurred when using molybdenum titanium dioxide valve trays, especially when it was opened and closed. A new tower is usually damaged in about half a year. The float valve in the tower loses 50% within half a year, which greatly reduces the separation efficiency and seriously affects the production. It is replaced every year, which increases the investment and production cost. The ceramic corrugated packing with a diameter of 800mm is used, which operates normally, improves the efficiency, reduces the reflux ratio, reduces the content of formaldehyde and formic acid at the top of the tower, and reduces equipment corrosion. Since the packing resistance is significantly reduced, the pressure in the kettle is reduced, and the steam consumption is reduced, and the ceramic corrugated packing has no corrosion problem.