## 1 Introduction  
Dust pollution has long been a significant environmental and occupational hazard problem in industrial and mining enterprises, and the associated health risks have become a critical concern [1; 2; 3]. As a result, the development and application of dust suppression technologies have attracted much attention in recent years, and spray dust suppression technology, as one of the most commonly used methods for controlling dust, has received extensive research attention [4; 5; 6]. The effectiveness of spray dust suppression technology is closely related to the atomization effect of the spray, which can be affected by various factors, such as nozzle parameters, including atomization angle and jet length [7], spray angle [8], and pressure [9]. However, the influence of the physicochemical properties of the spray solution, such as surface tension and viscosity, on the atomization effect has received less attention.  
Related studies have shown that surface tension and viscosity can significantly affect the collision and agglomeration behavior of droplets [10; 11], which can alter the particle size and velocity distribution of droplets in the spray field and consequently affect the atomization effect. Compared to atomization, factors such as pressure, surface tension, and viscosity have a more significant impact on the atomization effect [12; 13]. This is particularly significant in the context of spray dust suppression solutions, as many chemical surfactants have been applied to tackle the pollution problems caused by respirable and hydrophobic dust in recent years. These surfactants can change the surface tension and viscosity of the spray solution [14; 15; 16], making it essential to investigate the influence of these properties on the atomization effect to improve dust suppression efficiency.  
While some scholars have investigated the atomization effect of circular hydraulic nozzles for agricultural use [17] and fan-shaped nozzles for scenic areas [18], current research on the commonly used solid cone nozzles in industrial and mining enterprises is insufficient. Furthermore, few studies have examined the relationship between surface tension, viscosity, and the atomization effect of these nozzles, which is critical for understanding the mechanism of spray dust suppression and optimizing its effectiveness. Therefore, this study aims to investigate the influence of surface tension and viscosity on the atomization effect of solid cone nozzles to improve dust suppression efficiency.  
In addition, various instruments and devices can be used to study the relationship between surface tension, viscosity, and atomization effect, including the Malvern laser particle size analyzer [19], holographic particle velocity [20], and image comparison methods [21]. However, the Doppler particle size analyzer has become a highly recognized instrument that can improve testing accuracy and stability with the development of science and technology. Previous studies by [PERSON] [22], [PERSON] [23], and [PERSON] [24] using the PDPA have provided a theoretical basis for testing the size, velocity, and volume concentration of droplets in the spray field and have accurately processed the data using the PDPA system. This technique can be used to investigate the influence of surface tension and viscosity on the atomization effect of solid cone nozzles.  
In response to the limitations identified in the aforementioned study, this study investigated the influence of surface tension and viscosity on the atomization effect of solid cone nozzles using a self-designed PDPA dust-mist coupling experimental system. The atomization principles were applied to adjust the fog field characteristics of solid cone nozzles to improve their dust reduction rate, providing guidance for effective dust reduction in industrial and mining enterprises.