Study On The Main Characteristics Of Thermal Plasma Torch

As the development of our national economy,people’s requirements for the quality of environmental are increasing.At present,the solid waste treatment in our country is still mainly landfill and incineration,which has certain defects and low resource utilization rate.With the characteristics of high temperature and high energy density,thermal plasma has great potential in the application of solid waste harmless and resource.In this paper,the basic characteristics of the thermal plasma torch designed by the laboratory are studied.The volt-ampere characteristics of thermal plasma torch and its influencing factors are investigated.The results show that when argon,nitrogen and carbon dioxide are used as working gas,the volt-ampere characteristics are similar to those of arc discharge.The voltage and power of the plasma can be increased by increasing the inner diameter of the electrode and the flow rate of the working gas.When the working current and flow are the same,the voltage and power of carbon dioxide is the largest,followed by nitrogen,and argon is the lowest.The jet length of nitrogen and carbon dioxide is much longer than that of argon.The carrier gas with high flow rate is easy to form turbulent thermal plasma,while the carrier gas with low flow rate is easy to form laminar thermal plasma.The laminar thermal plasma has longer jet,better axial energy output and more stable and quiet operation.When nitrogen is used as carrier gas,a stable laminar thermal plasma can be formed when the inner diameter of electrode is 8mm,the working current is 100A and the flow rate is 10L/min.the jet length can reach 45cm.The results show that when the inner diameter of the electrode is 6mm and the gas flow rate is 10L/min,the working current is 100A,the excitation temperature of the thermal plasma is 11300K,the electron density is 10²³m^-3,and the thermal plasma reaches the local thermodynamic equilibrium.By increasing the current,the temperature of thermal excitation can be effectively increased.Cause the thermal plasma torch is in direct contact with the plasma in the work,the heat dissipation directly affects the working stability and sustainability of the torch.In this paper,the heat transfer characteristics of the thermal plasma torch are studied by numerical simulation.It is found that the cooling effect is good when copper is used as material.The temperature field distribution of torches with different thickness of copper wall is studied.The results show that increasing the thickness of copper wall can improve the heat dissipation.At the same time,there is room for improvement in the design of the torch,and the fins have a great influence on the convection field.