I design wood pellet factories and as you all know, the dust is highly flammable. The designs so far haven't had any fire suppression and extinguishing systems (in the EU). Now we're making a new kind of mixing machine that contains quite a lot of the stuff and is indoors. If there's gonna be rock pebbles inside, the thing may explode easily. It's connected to a conveyor by a hopper.

Any suggestions as to what are the most sensible ways to make it safer?