10-04-2012, 02:53 PM
Plasma Arc Cutting
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Plasma Arc Cutting
PAC is a thermal material removal process that is primarily used for cutting thick sections of electrically conductive materials.
Plasma can be defined as a “superheated, electrically ionized gas.”
PAC Process
PAC uses a high velocity jet of plasma (Temperatures range from 10,000 to 14,000 oC) to cut through the metal by melting it.
The high gas flow rate facilitate the removal of molten metal through the kerf
Stream pressures can reach up to 1.4 MPa.
Gases Used
Primary Gases:
Gases that are used to create the plasma arc. Examples are nitrogen, argon, hydrogen, hydrogen, or mixture of them
Secondary Gases or Water:
Surrounds the electric arc to aid in confining it and removing the molten material.
Arc Starting Circuit:
High frequency generator circuit that produces a high AC Current.
To start the arc, the AC current ionizes the cutting gas, which makes it conductive to allow the DC current to flow through it.
Applications
Pipe industry – preparing pipe edges for welding.
industries for shape cutting
Safety Precautions
Machine the heat affected zone (0.75-5 mm).
Regulate gas pressure (approx. 1-1.4 MPa).
Maintain constant distance between torch and work piece.
High labor safety (i.e. goggles, gloves, etc…).
Proper training for operators.
Protection against glare, spatter and noise from the plasma.