Tower equipment is one of the key unit equipment in chemical production. Tower equipment facilitates full contact between gas (vapor) and liquid phases, or between liquid phases, for mass and heat transfer. Unit operations completed through tower equipment include distillation, absorption, desorption, extraction, washing, cooling, and gas humidification.

Tower equipment is divided into plate towers and packed towers based on their internal structure. Plate towers are equipped with a certain number of trays, where gas enters from the bottom of the tower and liquid enters from the top. Mass transfer occurs between rising gas and falling liquid on each tray. Packed towers contain a layer of packing material of a certain height; if the required packing height is high, the packing can be divided into several sections. Liquid flows downward in a film-like manner along the surface of the packing, while gas passes upward through the packing layer, contacting the film-like liquid for mass transfer. Tower packing is categorized into two types: loose packing and structured packing. The materials for loose packing mainly include metal, plastic, and ceramic; while structured packing is mainly made of metal sheets or wire mesh, as well as plastic wire mesh.