Numerical analysis and experiment on a plasma torch with hollow electrodes for hazardous waste treatment

Thermal plasma characteristics of a nontransferred plasma torch with hollow electrodes are numerically and experimentally investigated in the atmospheric condition. Distributions of temperature, velocity, and mass flux in the air thermal plasma are calculated both inside and outside the torch by varying its operational and geometrical conditions, such as gas flow rate, input current, and electrode diameter. The dynamic and static behaviors of are voltage depending on these operational and geometrical variables are experimented in a small-scale plasma torch, from which a similarity criterion representing a semiempirical relationship between the are voltage and other variables is determined to predict the operational characteristics of high-power plasma torches with hollow electrodes for hazardous waste treatment.