## 4 Results and Discussion
In Figure 2, the rotary feeder mounted at the bottom outlet of the pulverized coal storage bunker consists of an eight-compartment wheel and can operate at a speed of 16 revolutions per minute. After disconnecting the rotary feeder from the pipe through which it transfers pulverized coal, it was operated for one minute, and the amount of pulverized coal collected in a container was weighed. Each compartment of the wheel was calculated to transfer 390 g of coal. In this case, the rotary feeder can extract 16 \(\times\) 8 \(\times\) 390 g = 49,920 g, approximately 50 kg, in one minute and transfer approximately 3000 kg of coal per hour from the bunker to the pipe. The M16 measurement, as detailed in Table 3, was obtained from four distinct ports positioned at 45-degree intervals along the radial axis of the pipe at the burner inlet, as illustrated in Figure 4b. Twelve individual measurements were recorded for each port, and their averages were computed. Subsequently, the average values derived from each of the four ports were aggregated to provide a final mean value, presented in Table 3. Upon examining the data presented in Table 3, with a primary air flow rate of 5803 Nm\({}^{3}\)/h, 2941 kg/h of pulverized coal can be transported through a 300 mm diameter pipe at a velocity of 22.81 m/s. It has been concluded that 1 kg of pulverized coal can be transported with 2 Nm\({}^{3}\) of primary air. According to the M\({}_{4}\)17 measurement taken at the measurement port mounted on channel 4, the velocity of the primary air and pulverized coal mixture has been determined to be 18.23 m/s. Measurements were conducted at three ports mounted at 60-degree intervals along the radial axis of channel 4. The average of six measurements taken at each port was calculated. The averages from these three ports were then further averaged, and the results are presented in Table 3. Following the stabilization of the damper opening at 25 degrees, the M16 measurement determined that out of the total 2941 kg/h of pulverized coal, 652 kg/h passed through channel 4. In conclusion, 22% of the pulverized coal transported by the primary air (652 kg/h out of 2941 kg/h) passed through channel 4 and interacts with the plasma flame for combustion. The same measurements conducted on channel 4 were also performed on channel 5. The values obtained from measurement 18 (M\({}_{5}\)18) on channel 5 are presented in Table 3. The velocity of the primary air and coal mixture was measured at 77.31 m/s. A total of 78% of the coal (2261 kg/h out of 2941 kg/h) was transported by the primary air and passed through channel 5. The primary air and coal mixture entering channel 5 of the burner was subsequently ignited by the flame produced from the plasma interaction with the coal entering channel 4. As the coal feed rate to the burner reached 3000 kg/h, the magnetron consumed 37.5 kWh of energy. The specific microwave consumption per kilogram of coal is calculated as Q = 37.5 kWh/(2941 kg/h \(\times\) 0.22) = 0.058 kWh/kg. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Parameters** & **M16** & **M\({}_{4}\)17** & **M\({}_{5}\)18** \\ \hline damper position [\({}^{\circ}\)] & 25 & 25 & 25 \\ static pressure [Static, Pa] & 285 & 362 & 410 \\ temperature [T, \({}^{\circ}\)C] & 27 & 27 & 27 \\ density [\(\rho\), kg/m\({}^{3}\)] & 1.16 & 1.16 & 1.16 \\ \({}^{\star}\) differential pressure [\(\Delta\)Pdifferential, Pa] & 278 & 190 & 297 \\ velocity [V, m/s] & 22.81 & 18.23 & 72.31 \\ primary air flow [Q, Nm\({}^{3}\)/h] & 5803 & 1160 & 4600 \\ total number of ports used in the measurement [TNP] & 4 & 3 & 3 \\ number of sampling points at each port [NSP] & 12 & 6 & 6 \\ sampling time at each point [s] & 30 & 30 & 30 \\ total sampling weight [g] & 2164 & 1079 & 3742 \\ total coal flow [kg/h] & 2941 & 652 & 2261 \\ \hline \hline \end{tabular} \({}^{\star}\) The differential pressure values represent the average values measured at each port.  
\end{table} 
Table 3: Primary air-pulverized coal measurements.