# Research on the Influence of Dust Suppressants on the Coupling Behavior of Dust-Mist Particles
## 4 Results and Discussion
### Influence of Suppressant Materials on Atomization Parameters of Spray
#### 4.1.3 Influence of Suppressants on Atomization Effect of Spray  
According to [PERSON]'s principle and [PERSON]'s second law, an increase in pressure results in a corresponding increase in the force exerted on the particles [43; 44]. As a whole, the trends indicate an inverse relationship between spray pressure and D32 size values. As spray pressure increases from 2.0 to 6.0 MPa, D32 values systematically decrease. The most prominent effects are observed at higher pressures (6.0 MPa), as shown in Figure 10. Change rate refers to the variations in particle size of the tested suppressants compared to water.  
The change trend of the D32 size value increases with the dust suppressants in the order DA \(>\) OP-10 \(>\) SDS \(>\) water. As the pressure increased, the mean D32 value of DA decreased from 36.65 \(\upmu\)m at 2.0 MPa to 23.24 \(\upmu\)m at 6.0 MPa. Similarly, the OP-10 D32 value decreased from 34.89 \(\upmu\)m at 2.0 MPa to 22.39 \(\upmu\)m at 6.0 MPa, the SDS D32 value decreased from 32.84 \(\upmu\)m at 2.0 MPa to 21.88 \(\upmu\)m at 6.0 MPa, and the water D32 value decreased from 29.65 \(\upmu\)m at 2.0 MPa to 21.01 \(\upmu\)m at 6.0 MPa. For the 5.0 cm measurement position, the average D32 value of the dust suppressants decreased from 35.42 \(\upmu\)m at 2.0 MPa to 20.38 \(\upmu\)m at 6.0 MPa. For the 7.0 cm measurement position, the average D32 value decreased from 37.75 \(\upmu\)m to 22.23 \(\upmu\)m, and for the 9.0 cm measurement position, the D32 values decreased from 38.02 \(\upmu\)m to 24.66 \(\upmu\)m. For the 10.0 cm measurement position, the D32 values decreased from 33.94 \(\upmu\)m to 23.37 \(\upmu\)m, and for the 15.0 cm measurement  
Figure 10: Influence of dust suppressants on atomization.  
position, the D32 values decreased from 26.41 \(\upmu\)m to 21.20 \(\upmu\)m. The average D32 value of the dust suppressants was 33.45 \(\upmu\)m at 2.0 MPa, 25.72 \(\upmu\)m at 4.0 MPa, and 22.13 \(\upmu\)m at 6.0 MPa. The average D32 value of the dust suppressants across the different spray pressures was 26.24 \(\upmu\)m at 5.0 cm, 29.25 \(\upmu\)m at 7.0 cm, 29.49 \(\upmu\)m at 9.0 cm, 27.11 \(\upmu\)m at 10.0 cm, and 21.50 \(\upmu\)m at 15.0 cm.  
The relationship between the change rate and the measuring points for three dust suppressants DA, OP-10, and SDS is shown in Figure 10d. The water value was used as the reference baseline in this study. The change rate of the average size of the D32 across the different measuring points was calculated using the averaged data of water and each suppressant. As a whole, the change rate of the dust suppressant fluctuates up and down; the change rate of DA is the largest, with an average value of 18.2%, followed by OP-10, with an average value of 12.6%, and SDS, with an average value of 8.2%. The mean change rate of DA is 2.25 times greater than that of the SDS value and 1.38 times greater than that of the OP-10 value. According to the results in Figure 2a, the greater the reduction in surface tension DA \(>\) OP-10 \(>\) SDS, the larger the change rate. It is observed that when the surface tension of solutions is lower, the particle sizes of droplets tend to be larger. Consequently, the dust suppressant is less effective in promoting the atomization of smaller particles.