The Tower, a process equipment for cylindrical welding structure, compose with shell body, head (or cover) and support. is applied to distillation, absorption, extraction in order to complete the chemical industry heat and mass transfer process.

According to its structure can be divided into two types: plate column and packed column.

Commonly used with bubble tower, packed tower, serive-plate tower, shower plate, float valve tower, keiteltower, shap-ed tower(S type tower), tongue type tower, circulate plate tower, rotary disc tower and guided sieve tray tower.