INDUSTRIAL PLASMA TORCHES AND APPLICATIONS

Abstract

Plasma technology has given a new direction and impetus to many industrial operations by opening up a new range of mechanical, chemical and metallurgical processing techniques. The high temperatures together with the highreactivity due to the presence of free ions and radicals, make the plasma a powerful medium to promote high heat transfer rates and chemical reactions. This paper focuses on atmospheric plasmas known as thermal-plasmas produced by plasma torches. Conventionally, as in plasma cutting, welding, melting or spraying operations, the plasma torch acts as a source of highly concentrated thermal energy and the plasma-forming gas provides an inert atmosphere and helps to prevent undesirable reactions, thus ensuring the purity of the operation and the product. In contrast, the emerging trend is to use reactions, where the plasma gas enters the reaction scheme. Some of the above issues are reviewed and illustrated with examples of plasma torches developed and experiments carried out at Bhabha Atomic Research Centre (BARC), Mumbai.