The influence of air flow on maximum explosion characteristics of dust–air mixtures

A standard spherical apparatus for measuring explosion characteristics was modified to give increased and controlled turbulence within a dust–air mixture. This was intended to mimic the local effects which may occur during industrial dust explosions, particularly secondary ones which may develop in ducts or mine galleries where the initial explosion causes an increased air velocity and suspension of further quantities of dust.The results show that there may be a doubling of the maximum explosion pressure and of the rate of pressure rise during the explosion under more turbulent conditions. This is significant for modelling of dust explosions and suggests that explosion relief may be inadequate if this factor is not taken into consideration.The modified apparatus therefore gives a laboratory method for assessing the effect of turbulence in dust explosions.

► Study the influence of flow of air masses on dust–air mixtures.
► Measurements were done in a spherical explosion test apparatus VA-250.
►  5 different samples of industrial dusts had been selected.
► Smooth wheat flour, brown coal, powdered sugar, meat–bone powder, torula yeast.
► Increasing of the maximum explosion pressure and brisance.