precipitator

noun3

1. •
   A person who, or device that, carries out precipitation.
2. •
   An apparatus which removes dust particles from gases by electrostatic precipitation.
3. •
   One who or that which precipitates (causes something to happen or urges it on with vehemence or rashness).

   • Even the most wanton precipitators of war always try to give it, in the eyes of the common people, a defensive character. — 1918