Abstract: In order to learn explosion characteristics of the grain dust collected from the dust removal system for bolting procedure in beer enterprise in China,experiments were carried out by means of an 1.2 L Hartman dust explosion test facility. Influences of particle size, mass concentration, moisture content and on the explosion pressure (P) and the rate of pressure rise (dP/dt) were studied.The results show that grain dust LEL is between 125-166.67 g/m³, that the P_max is 1.81 MPa and (dP/dt)_max is 10 MPa/s when the concentration is 291.67 g/m³,that the change in P and dP/dt are similar, that the increase of the particle size from 98-105 μm to 180-1 250 μm makes the LEL increase from 50-58.33 g/m³ to 141.67-150 g/m³ and the explosion pressure drop from 0.9 MPa to 0.72 MPa,and that the decrease of moisture content from 6.39% to 0% (absolute dry condition) makes explosion pressure increase from 1.3 MPa to 2.1 MPa.

Key words: grain dust, lower explosion limit(LEL), explosion pressure, rate of pressure rise, particle size