Tweco 15XC CE Merlin PAK - Manual (Page 20)

INTRODUCTION & DESCRIPTION 1 - 6 Manual 0-2529
1.5 THEORY OF OPERATION
Figure 1-D Theory of Operation
Plasma Arc Cutting and
Gouging
Plasma is a gas which is heated to an extremely high
temperature and ionized so that it becomes electrically
conductive. The plasma arc cutting process uses this
plasma to transfer an electric arc to a workpiece. The
metal to be cut is melted by the intense heat of the arc and
then blown away. The Thermal Arc Merlin PAK 15XC is
a high performance plasma cutting system designed to cut
most metals up to two inches thick.
With a simple change of torch parts, the system can also be
used for plasma arc gouging. Plasma arc gouging is used
to remove material to a controlled depth and width.
The Thermal Arc torch uses a cool plasma gas such as
compressed air, nitrogen, argon/hydrogen, or oxygen.
The plasma gas flows into the torch through the plasma
torch lead and is channelled into Zone A (Figure 1-D),
where a pilot arc between the torch electrode and tip heats
and ionizes the gas. The main cutting arc transfers to the
workpiece through the column of plasma gas as it flows
out through the torch tip orifice. Plasma Gas Flow
;;
;;
;;
;;
;
;
;
;
;;
;;
;;
;
;;
;;
;
;;
;;;
;;;
;;;
;;;
;;;
;; ;
;
;
;
;
;
A-00900
Power Supply
Workpiece
Coolant
Plasma Gas
Secondary Gas
Zone A
Zone B
Zone D
Zone C
(-)
(+)