Stable operation region and dynamic behavior of Ar pulse‐modulated induction thermal plasma with different molecular gases

Abstract

SUMMARYThe pulse-modulated induction thermal plasma (PMITP) was established in Ar gas with additional gases such as H 2 , O 2 , N 2 , and CO 2 to investigate the effects of various gas inclusions on the transient characteristics of thermal plasma. The dynamic response times of the thermal plasmas were estimated from the measured time-varying radiation intensity of Ar spectral line. Furthermore, time evolution of the Ar excitation temperature was determined by the two-line method. The results indicated that especially in Ar-CO 2 PMITP, decreasing the current level in a modulation cycle raised the on-delay time which means a recovery time from a low-temperature state to a high-temperature one. In addition, the inclusion of CO 2 in Ar PMITP caused lower temperatures just before the on-operation compared with other gases used in the experiment.

Nanoparticle synthesis using high-powered pulse-modulated induction thermal plasma

“…We have developed a high-power pulse-modulated induction thermal plasmas (PMITP) system for use at a rated power of 30 kW and have investigated its fundamental features [21][22][23][24]. The PMITP system has the function of amplitude modulation of the coil current sustaining the induction thermal plasma into a rectangular waveform.…”

Controlling the number of excited atoms flowing into the reaction chamber using pulse-modulated induction thermal plasmas at atmospheric pressure

“…To control this high enthalpy and temperature and to add a new function into the ICTP system, Ishigaki and our group have developed a pulse-modulated induction thermal plasma (PMITP) system [11][12][13][14]. This system can modulate the amplitude of the coil-current that sustains induction thermal plasmas.…”

“…In particular, chemical non-equilibrium effects might provide new chemical reaction fields in high-power atmospheric-pressure plasma, which can be useful in advanced material processing. The PMITP can also be used for the fundamental investigation of transient thermal plasmas, such as switching arcs in a circuit breaker [18,19].…”

“…To date, we have investigated the dynamic behaviours of Ar PMITPs with the molecular gases H 2 , N 2 , O 2 and CO 2 . In these studies, we have focused on the high-temperature region in the plasma torch using both experimental and numerical approaches [15][16][17][18][19][20]. Both these approaches have shown that the minimum temperature of Ar thermal plasma with additional molecular gases can be controlled by setting the shimmer current level (SCL) while its maximum temperature in a modulation cycle is retained [15,19,20].…”

“…In these studies, we have focused on the high-temperature region in the plasma torch using both experimental and numerical approaches [15][16][17][18][19][20]. Both these approaches have shown that the minimum temperature of Ar thermal plasma with additional molecular gases can be controlled by setting the shimmer current level (SCL) while its maximum temperature in a modulation cycle is retained [15,19,20]. Moreover, it was found that the inclusion of CO 2 causes a large temperature variation in the PMITP due to the modulation of the coil current [15,19].…”