Engineering the bore shape to improve performance of a plasma torch

Design changes were made to a conventional plasma torch to improve its performance. The existing cylindrical bore of the torch was replaced with a convergent divergent shape. Experiments were conducted which showed significant reduction in torch segments temperature. As a result, the efficiency of the torch increased by 4% and the argon consumption was reduced by 33%. An increase in enthalpy of the plasma mainly due to the reduced argon flow rate would also increase the processing capacity of the torch. The theoretical estimates made using a torch model showed considerable change in the heat load distribution on the torch segments, which agreed well with the experiments.