## 3 Results and Discussion
### Ignition Temperature of Airborne Dust  
[PERSON] et al. (2019) studied the processes of ignition within airborne wood dusts. They ([PERSON] et al., 2019) studied the specificities of the dust ignition process in different stages. The first stage is the beginning of an explosion: The dust was sprinkled into a ceramic tube furnace, with dust carbon residue. In the second stage, the unburned wood dust was ignited with the most incredibly intense flame. Subsequently, in the third state, flame slowly diminished with side effects.  
The ebony dust of 500 \(\upmu\)m, 315 \(\upmu\)m, and 71 \(\upmu\)m fractions were obtained the maximum flame (Figure 8). It was noted that when using larger particles, the flame had a lower intensity.  
These results determined that the ignition temperature of airborne dust (Figure 9) showed a reduction in values relating to the smaller size fraction ([PERSON] et al., 2019).  
The minimum ignition temperature of cumaru for the 500 \(\upmu\)m fraction was 410 \({}^{\circ}\)C, and this temperature decreased with changing particle size.  
Particles of 100 \(\upmu\)m or less had the most significant effect on the change in the minimum temperature. The minimum ignition temperature of the ebony dust particles 500 \(\upmu\)m, and 200 \(\upmu\)m was identical (400 \({}^{\circ}\)C). The 100 \(\upmu\)m particle fraction had a minimum ignition temperature of 380 \({}^{\circ}\)C. The last three size fractions had minimum ignition temperatures, due to strong dispersion in the heating furnace. An assumption was made applied to a larger dispersion of particles in a space for larger particles (of 500 \(\upmu\)m), compared to 100 \(\upmu\)m with the same weight of the batch.  
Marblewood had the highest tested minimum ignition temperatures of all samples. The minimum ignition temperatures started from 400 \({}^{\circ}\)C at a particle size of 500 \(\upmu\)m to 100 \(\upmu\)m. Subsequently, the minimum ignition temperatures decreased with the particle size change to the level of 400 \({}^{\circ}\)C, at a particle size of 63 \(\upmu\)m.  
Flame propagation behaviors and temperature characteristics of four types of biomass (poplar, pine, peanut, and corn sawdust particles) with two different particle sizes (50-70 \(\upmu\)m and 100-200 \(\upmu\)m) distributions were studied experimentally by [PERSON] et al. (2019). The average flame propagation velocity and the amplitude of the velocity fluctuation are functions of the mass density of the biomass particles and depend on the particle size distributions ([PERSON] et al., 2019).  
Tropical woods came to a global market for their use in various products. Information about tropical wood fire parameters is poor. Fire parameters are not described in Safety Data Sheets (2017); [PERSON] et al. (2019). [PERSON] et al. (2019) studied the heat transfer in Brazilian woods, using a sample that was thermally loaded to examine the potential for fire. Their results showed that there are curves of temperature on the time experiments that create the thickness\(f\) chair layer corresponding with [PERSON]'s numerical models.  
Figure 8: The flame on ignition (conditions: 0.2 g of dust, air pressure of 30 kPa, the temperature of the ceramic tube furnace 500 \({}^{\circ}\)C). Images were prepared using a Basler a602 fc-2 high-speed camera (Basler AG, Ahrensburg, Germany). Legend: (**a**) Point of ignition for fraction 500 \(\upmu\)m of ebony dust; (**b**) point of ignition for fraction 315 \(\upmu\)m of ebony dust; (**c**) point of ignition for fraction 71 \(\upmu\)m of ebony dust.