olishing powders, metal powders, fibrous dust, larger particles of wood and shavings. The dust in the metal processing workshop is flammable dust, and when the flammable dust meets the following three conditions, a dust explosion will occur.

1. Combustible dust is suspended in the air at an appropriate concentration, forming what is often called a dust cloud;

2. Sufficient air and oxidant;

3. There is fire source or strong vibration and friction.