Packed towers are used for furnace gas drying and sulfur trioxide absorption for sulfuric acid production. The tower body is a steel shell lined with asbestos board and then lined with acid-resistant ceramic tiles. The filler is a porcelain stepped ring or saddle ring, etc. There are two types of eliminators: wire mesh eliminator and fiber eliminator. There are two common forms of acid distributors: trough tube type and tube type.

In recent years, the emerging high-strength packed tower has the characteristics of high gas velocity and low packing height. The new technology and structural characteristics require circulating sulfuric acid to be quickly and evenly distributed along the tower section. The trough-tube type acid distributor with anode protection has the characteristics of high acid distribution points per unit area to meet this requirement, and it is the new favorite and development direction of acid distributors in dry absorption towers in recent years.

The structure of the horizontal concentrated acid circulation tank is a steel horizontal cylinder, and the steel shell is lined with asbestos board and then lined with acid-resistant ceramic tiles.