Developments in Plasma Cutting

For some time the principle of using cold jets of gas to pinch the plasma arc and to cool the top surface of the work-piece has been known and applied. More recently, water curtains have been used for the same purpose with some extra advantages claimed. Again, a different gas has been tried to provide a curtain or "focussing" means, for example, carbon dioxide as the curtain gas and nitrogen as the plasma gas.