A multi-cyclone is a type of air pollution control device used to remove particulate matter (PM) from industrial processes, particularly from flue gas streams. 

Some common uses of multicyclones in industry include:

1. Cement industry: Multicyclones are used to control PM emissions from cement kilns and other cement manufacturing processes.

2. Steel industry: Multicyclones are used to control PM emissions from steelmaking processes, including blast furnaces and electric arc furnaces.

3. Power generation: Multicyclones are used to control PM emissions from coal-fired power plants, where fly ash and other PM emissions are generated during the combustion process.

4. Chemical processing: Multicyclones are used to control PM emissions from various chemical processing operations, such as spray dryers and fluidized bed reactors.

5. Woodworking industry: Multicyclones are used to control PM emissions from woodworking operations, such as sawmills and furniture manufacturing.