# Investigations of Working Characteristics of Transferred Arc Plasma Torch Volume Reactor
## 3 The Results of the Experiment
As it can be seen from the results presented, the lowest temperature value of 640 \({}^{\circ}\)C was obtained when the thermocouple is in the starting 0 mm position. The temperature rises up to 1100 \({}^{\circ}\)C when measured at a position of 30 mm corresponding to the center of the measuring hole. Moving further towards the 60 mm position, the temperature reaches 800 \({}^{\circ}\)C. As it is observed to be moving along the entire length of the orifice diameter, the temperature distribution is uneven [1; 2; 3]. The highest temperature value is at the middle of the opening and the lowest values are at the edges of the opening. The uneven distribution of temperature values can be qualitatively explained by gas flow properties and the distribution of the degree of ionization. The degree of ionization of the plasma-forming gas at the center of the orifice is the highest, which results in the highest concentration of plasma-forming electrical particles at this location, which is why we have the highest temperature at this location. Meanwhile, at the edges of the orifice, the degree of ionization of the plasma-forming gas is significantly lower; thus, the concentrations and temperature of free electrical particles are lower. This temperature profile is also determined by the phenomena of gas ejection, which makes both the density and velocity of the gas uneven. The distribution of the plasma flow potential difference along the volume reactor was measured during the experiment. A metal probe was used for these measurements when one end of the cable connected to the probe and the other to a grounded electrode. The scheme used to measure the electric arc potential difference is shown in Figure 5. The measurements were performed at five points in every 50 mm. Figure 3: The dimensions of the opening for the temperature profile measurements at the cooled wall and the steps of the thermocouple movement. The distance between the anode surface and the temperature measurements plane is 100 mm. The values obtained for the potential difference during the experiment are average because the motion of the electric arc is chaotic throughout the reactor volume. The plasma arc potential difference measurements were performed at certain time intervals inside the reactor in the presence of the treated material. The results of the measurements are provided in Table 1. As observed, the difference in the potentials along the length of the reactor changes slightly at some point in time. At 6 min of the experiment, the potential difference in the reactor volume varies between 2.2 and 3.2 V. This result can be explained by the fact that, at the beginning of the experiment, the treated material (clay and hydroquinone mixture) did not melt and covered most of the surface of the graphite anode. Meanwhile, the inequality of the potential at different points is also determined by the fact that the density of the plasma-forming gas is not equal throughout the volume of the reactor due to the unequal temperature inside the reactor. In addition, the unequal distribution of electrical potential was determined due to the fact that the plasma arc moves chaotically throughout the reactor. When the duration of the experiment reaches 40 min, the potential of the electric arc increases significantly and its values change in the range of approximately  
Figure 4: The dependence of temperature profile on the diameter of the cooling wall hole. Figure 5: The schematic diagram for measuring the difference in plasma electric arc potentials. Measurements were performed with a cooling probe every 50 mm. 40-43 V. At this time value, the processed clay transitions from the solid phase to the liquid electrically conductive phase. These phase transitions of the material also affect potential difference values. In the case of conductive liquid phase, the electrical potential difference increases significantly.