Thermal plasma processes for use in research and development

Many potential thermal plasma processes exist, however surprisingly few processes have been developed to the stage of commercial viability. Possible processes exist where the scale and the potential gain is such that the high costs of process development cannot be justified and versatile equipment at moderate cost suitable for small scale evaluation at power levels below 500 kW does not exist. Equipment requirements cannot be accurately specified since process variables such as voltage and current are very dependent on the application. The time taken by the user to develop the equipment and evaluate the process may be considerable, costly and outweigh the potential gains even if successful. Available equipment is large and expensive, requires a large floor area and is more suited to the foundry. Existing equipment is intended for continuous rather than batch operation and accordingly has long thermal time constants measured in days rather than hours. The design of a versatile furnace suitable for processes requiring temperatures up to 2200°C is described