Combustible dust may result in a catastrophic dust explosion with much larger accident consequences than that of combustible gas or vapors. By considering the significant contribution of dust layer fire to dust explosion, fire hazards of dust layer were investigated to clarify the possible worsening situation induced by the properties of deposit surface. The results showed that the effect of thermal conductivity of deposit surface on layer fire hazard was complex even for the same powder material, which depended on the contribution of conductivity to the layer flame spreading. Good permeability of the deposit surfaces (e.g., metal gauze) could contribute to a bottom fire with high flame height and temperature. For whatever deposit surfaces (i.e., ceramic and metal plate, or metal gauze), the inclination angle of the dust layer could result in a high flame spread velocity (FSV). As a result, good permeability deposit surfaces coupled with a large inclination angle would significantly enhance the fire hazard of the dust layer, which should be taken enough consideration in the powder process industries or public activities where combustible powders were used.

可燃粉尘可能导致灾难性粉尘爆炸，其事故后果比可燃气体或蒸气要大得多。考虑到粉尘层火灾对粉尘爆炸的重大贡献，研究了粉尘层的火灾隐患，以阐明沉积物表面特性可能导致的恶化情况。结果表明，即使对于相同的粉末材料，沉积物表面的热导率对层火危害的影响也是复杂的，这取决于电导率对层火焰蔓延的贡献。沉积物表面（例如金属丝网）的良好渗透性可能会导致火焰高度和温度较高的底火。对于任何沉积表面（例如，陶瓷和金属板或金属丝网），灰尘层的倾斜角度可能会导致较高的火焰传播速度（FSV）。结果，良好的渗透性沉积表面以及较大的倾斜角度将显着增强粉尘层的着火危险，在使用可燃粉的粉末加工行业或公共活动中应充分考虑这一点。