Cation exchanger refers to a system where water flows through a cation bed of hydrogen form cation exchange resins. The hydrogen form cation bed is used to remove cations from the water. Mineral salts can be generally removed from the water via the cation exchanger. To achieve better desalination effect, cation bed usually contains strong acid cation exchange resins.

Cation exchanger is mainly applicable to boilers, thermal power plants, chemical, textile, pharmaceutical, biological, electronics, and atomic energy industry, pure water pre-treatment, industrial water softening, and deionized water preparation, as well as decolorization and purification of foods and drugs, recycling of precious metals and chemical raw materials, and electroplating wastewater treatment, etc.