descale
verb [ T ] uk/ˌdiːˈskeɪl/ us/ˌdiːˈskeɪl/
除去…的水垢;对…进行除垢处理
to remove scale (= a layer of hard white material) from something
The water heater needs descaling. 这个热水器需要除垢了。
descaler
uk/ˌdiːˈskeɪlər/ us/ˌdiːˈskeɪ.lɚ/
除垢剂
a substance used for descaling things