Experimental study on the explosion limits change laws under gas and coal dust coexisting conditions

Using 20 Lnearly spherical explosion characteristic test system, studied the change laws of explosion limits under gas and coal dust coexisting conditions. The study found that:under the experimental conditions, coal dust lower explosion limit decreases with the increase of the gas concentration, pure coal dust lower explosion limit is 28.4g/m³, while adding 1.70% gas its lower explosion limit down to 7.8g/m³, coal dust lower explosion limit and gas concentration are exponential relationship; gas upper explosion limit alters with the increase of the coal dust concentration, pure gas upper explosion limit is 15.8%, while adding 100g/m³ dust its upper explosion limit down to 12.8%; gas lower explosion limit decreases with the increase of the coal dust concentration, pure gas lower explosion limit is 5.10%, while adding 100g/m³ dust its lower explosion limit down to 3.10%; gas upper explosion limit and lower explosion limit were exponential function relationship with coal dust concentration. The study results provided a theoretical basis for the prevention and control of coal mine gas and coal dust explosion accidents.