Experimental Study on Flame Spread of Pine Wood Dust Layer Under Horizontal Rotation Condition

Abstract

ABSTRACT The rotating discs of wood polishing machines and the rotating bases of winding machines rotate horizontally during operation, and a layer of wood dust may be deposited on their surfaces. The study of flame spreading of wood dust layer in the rotating state has not been reported in the literature. Based on this situation, in this study, the flame spreading of pine wood dust layers in three particle size ranges under stationary and different rotating conditions were carried out and analyzed comparatively. The results show that the flame spreading speed of the pine wood dust layer from 74~100 micrometers positively correlates with the rotational angular velocity. The flame-spreading speed of a pine wood dust layer larger than 100 micrometers negatively correlated with the rotational angular velocity. This indicates that the flame spreading speed of the pine wood dust layer is affected by the combined effect of dust particle size and dust layer motion state. The flame propagation speed of the 74~100 micron pine dust layer was 3.3 mm/s when the rotational angular velocity was 0.167 rad/s, which was the maximum flame propagation speed in all experimental conditions. The maximum flame height of the pine dust layer in the rotating state was at least 55.6% higher than that in the stationary state.From the combined view of the three parameters of flame spreading speed, flame duration, and maximum flame height, the fire danger is greater in the rotating state than in the stationary state. Within a certain range, the larger the rotational angular velocity, the greater the fire hazard.