Abstract: In order to study the effect of calcium carbonate content on the minimum ignition temperature of wood dust layer, HY16430 dust layer ignition temperature test device was used to measure the minimum ignition temperature of polished painted wood dust layer, hand polished wood dust layer and their mixture with calcium carbonate respectively. The results showed that when the median particle sizes of polished painted wood powder, hand polished wood powder and calcium carbonate were 7.344, 7.269 and 7.859 μm, respectively, and the accumulated thickness of dust layer was 5 mm, the minimum ignition temperature of polished painted wood dust layer is 324 ℃, and that of hand polished wood is 332 ℃. The minimum ignition temperature of wood dust layer increases with the increase of calcium carbonate content by means of increasing heat absorption to accelerate heat consumption, reducing oxygen concentration and reducing wood dust concentration. When the mass fraction of calcium carbonate reaches 40%, the minimum ignition temperature of dust layer of polished painted wood and hand polished wood increase sharply, and the temperature mutation phenomenon appears. When the mass fraction of calcium carbonate reaches 70%, the minimum ignition temperature of the mixed dust layer of polished painted wood powder is 17.3% higher than that of the pure polished painted wood dust layer, and the minimum ignition temperature of the mixed dust layer of hand polished wood powder is 18.7% higher than that of the pure hand polished wood dust layer. When the mass fraction of calcium carbonate reaches 80%, the hot surface has been set to a maximum temperature of 400 ℃, but the dust layer does not ignite.

Key words: polished painted wood powder, hand polished wood powder, calcium carbonate, minimum ignition temperature