SVILUPPO DEL CONTROLLO DELLA TORCIA AL PLASMA

Industrial plasma torches hold significant importance across various fields due to their unique properties and potential applications such as clean hydrogen production, waste treatment, dangerous waste processing, steel making, and more generally any process requesting heat supply at high temperatures without CO2 emissions. For instance, a plasma torch, which is a device that converts electricity to heat at very high temperatures through arc discharges into a plasma gas, can be used to produce hydrogen and carbon powder via a chemical process called plasma methane pyrolysis involving the passage of methane through the arc discharge of a plasma torch which cracks the molecule of methane into hydrogen and carbon powder without emission of CO2. The arc plasma torch family uses electrodes to create the arc discharge. These electrodes, subject to very high temperatures are eroded and consumed with time. To obtain a stable operation, the tips of the electrodes, in a three-phase configuration implicating the use of three electrodes need to be at a fixed distance one from another. It is important to have an automated control system rather than a manually controlled system in order to have a stable system and optimized performance as well as a safe operation. This is the main overall goal of this thesis. Some experiments were conducted, and data analyzed to understand the behavior of the system. With respect to the analyzed data, a current controller for controlling the current of the arc was developed as well as two erosion compensation controllers which were based on computer vision of the electrodes position and voltage measurement of the arc respectively. Both erosion compensation controllers were developed and tested, and the results were discussed in detail in the results and discussion section where the voltage-based controller performed in a satisfactory way, meanwhile the vision-based controller did not hold the expected results exactly due to the immaturity of the detection system since it is still under development.