Precipitators

I believe you are talking about Electrostatic Precipitators or ESP Mist Eliminators or Industrial electrostatic air cleaners provide healthy indoor air quality via the most efficient and consistent operation of any current mist collecting technology. Other forms of machine coolant oil mist filters include media filtration and centrifugal separation. All three technologies are used to collect smoke and metal working fluid mist, though electrostatic precipitators generally outperform the other two smoke and mist eliminator filtration methods.

You go to Honeywell site and look for Electronic Air Cleaners.

They come in duct mounted & floor/ceiling mounted.

They have plates that are electrically charged. The air passes via filters and is charged. The dust particles having +ve charge impinge on -ve plates and vice versa.This cleans the air upto .001 micron.