# Temperature Fields of the Droplets and Gases Mixture
## 2 Experimental Set-Up and Procedure
### High-Temperature Gas Flow  
The experiments are divided in two types when generating a high-temperature gas flow: (i) containing flue gases (combustion products) from liquid fuel combustion and (ii) heated air generated by a heater and an air compressor. The choice of these two types of gas media for this research comes from the conditions of promising gas-vapor-droplet technologies [1; 2; 3; 4; 5]. For instance, heated air is used in rectification towers and thermal treatment chambers, whereas combustion products or a mixture of flue gases and air are used in direct-contact heat exchangers. Combustion products contain a mixture of flue gases and ash particles. Therefore, temperature reduction and subsequent stabilization can have different characteristics. Therefore, we are considering both types of gas media in this study. To generate a high-temperature combustion products flow similar to experiments [9; 10], we used the following elements (Figure 1); hollow cylinder of heat-resistant (up to 1800 \({}^{\circ}\)C) quartz glass 7 (1 m height, 0.2 m outer diameter), burner 9 comprised of a hollow cylinder (0.1 m height, 0.15 m and 0.19 m inner and outer diameter); TC-1 kerosene, a fuel with well-known and stable characteristics; and an exhaust system with an option to vary combustion product flow velocity (\(U_{\mathrm{a}}\)) of up to 3 m/s. To generate the combustion products flow with a controlled temperature (\(T_{\mathrm{a}}\)), we used the following procedure. Two-hundred-and-fifty milliliters of fuel was placed into the inner part of the burner and ignited using a piezoelectric lighter. A hollow glass cylinder was placed over the burner, and an upward flow of kerosene combustion products began to form in its inner chamber. Air was supplied into cylinder 7 through a hollow opening in the central part of burner 9. During the experiment, the flame height in cylinder 7 varied from 0.15 to 0.4 m. The average temperature of the gas-vapor mixture, leaving the quartz channel, was controlled by varying the air consumption (by using an exhaust ventilation system) in the range of 100 to 500 \({}^{\circ}\)C [9]. To evaluate the component composition of combustion products in the experiments, we used a Testo-340 gas analyzer with the following measurement ranges; O\({}_{2}\): 0-25%; CO: 0-10,000 ppm; NO: 0-3000 ppm; NO\({}_{\mathrm{x}}\): 0-3000 ppm; SO\({}_{2}\): 0-5000 ppm; accuracy: O\({}_{2}\): \(\pm\)0.3%; CO, CO\({}_{2}\), NO, SO\({}_{2}\): from \(\pm\)5% to \(\pm\)10%). The main concentrations were measured before the aerosol injection experiments started. The methods used in the experiments  
Figure 1: Scheme of experimental set-up: 1—video camera; 2—optical filter; 3—beam splitter; 4—Nd:YAG laser; 5—laser optics; 6—light sheet; 7—quartz cylinder; 8—air heater; 9—burner; 10—fast thermocouple; 11—slow thermocouple; 12—spraying nozzle; 13—position of BAM:Eu particles. are similar to those described in [9]. Thus, we determined the fraction of components, in particular, CO\({}_{2}\), CO, NOx, NO, SO\({}_{2}\), and O\({}_{2}\). Table 1 presents average concentrations of components in kerosene combustion products, obtained through measurements in this study. We also compared them with the data from the work in [9]. We found (Table 1) that the concentrations of the main components in kerosene combustion products, measured in this study, are close to the results from those in [9]. It is also clear that for the group of flammable liquids under study [9], the concentrations of the main combustion product components are generally quite close. Moreover, these concentrations are within the allowable level for typical boiler plants (in accordance with the Russian standard GOST R 50831-95). Thus, it is safe to say that using kerosene combustion products in the experiments makes it possible to simulate the conditions close to real technologies [1; 2; 3; 4; 5].