Plasma torch for treating surfaces at atmospheric pressure includes a jet pump within torch to provide low pressure region

摘要

The torch contains a driving jet (2) and a diffuser (3) acting as a jet pump to generate a low pressure of 900 to 100 hPa in the plasma chamber (4). The driving gas, e.g. inert gas, nitrogen, oxygen or a mixture, is supplied at pressures of 5 to 50 bar through a connection (5). The process gas is fed (6) through an annular gap into the plasma chamber (4). The electrical supply (9) is at 1000 V to 10000 V and can be direct current or alternating current between 50 Hz and 100 MHz or a microwave supply at greater than 1 GHz. Depending on the application, the process gas can be oxygen, hydrogen, nitrogen, steam, ammonia and can contain a precursor such as carbohydrates, silanes, siloxanes or metal organics.