The answer to the second question in advance: Like any organic dust, flour dust is combustible with atmospheric oxygen above a certain concentration. Therefore, milling operations must avoid flour dust deposits - otherwise there is a risk of a dust explosion when the dust is stirred up, which can lead to chain reactions with further dust explosions. Not to mention, of course, cleanliness is the hallmark of any food processor.
Flour dust a hazard?
Incidentally, the connection between flour dust and the risk of explosion was not recognized until around 1895, after several large explosions had occurred in industrial mills. Since then, mills have been equipped with fire extinguishing and dust extraction systems and attention has been paid to cleanliness.
Against this background, the answer to the first question is simple: flour dust (and also dusts generated, for example, in the production of baking powder, custard powder and cocoa powder, or in the grinding of coffee on an industrial scale) can and must only be extracted using dust explosion-proof vacuums. With these, numerous design measures ensure that explosive dusts can be extracted without risk.
Ruwac's solution!
For example, Ruwac's explosion-proof dust extractors are fundamentally free of ignition sources, i.e. there is no risk of sparks or heat being generated during operation that could trigger a dust explosion. The housing material used is an electrically dissipative, glass-fiber-reinforced thermoset. And very importantly, Ruwac's dust explosion extractors comply with the EU-wide ATEX directive for (dust) explosion protection. So with them, mill operators are not just playing it safe when it comes to hygiene.
Are you looking for a practical example? Take a look at a Ruwac application example for flour dust HERE.