Publicité
HVAD ER PLASMA-
SKÆRING
Plasmafysik
Plasmalysbuen er en meget koncentreret
lysbue, der opstår ved at lysbuen bliver
mekanisk
koncentreret
igennem et lille dysehul. Denne indsnæv-
ring giver temperaturer på 15000 - 25000°C
og hastigheden er omkring 2 gange lydens.
Den høje temperatur gør materialet flyden-
de og materialet presses væk af den kine-
tiske energi i lysbuen.
Plasma er den såkaldte fjerde tilstand, hvor
de tre andre er fast-, væske- og gasform.
Plasma er en elektrisk ledende gas med høj
energitilstand. For at en gas kan blive til
plasma, skal der tilføres energi, så moleky-
lerne spaltes til atomer, og disse atomer
spaltes til ioner og elektroner.
En ideel plasmagas er molekylær, har høj
varmeledningsevne, er let at ionisere og har
høj molekylevægt. Trykluft er velegnet som
plasmagas, dog skal brænderen have en
særlig udformning, idet der er ilt i trykluften.
fig. 1
og
indsnævret
WHAT IS PLASMA
CUTTING
Plasma physics
The plasma arc is a highly concentrated
arc, which occurs as the arc is mechanically
concentrated and constricted through the
small hole in the nozzle. This constriction
causes temperatures of 15,000-25,000°C,
and the velocity of the plasma beam is 2-3
times faster than that of sound. The high
temperature melts the material which is
then forced away by the kinetic energy of
the arc.
Plasma has been classified as a fourth
state of matter, the other three being mate-
rial, liquid and gaseous state. Plasma is a
conducting gas with a high concentration of
energy. Before a gas can turn into plasma,
energy must be supplied, so that the mole-
cules will dissociate into atoms and these
atoms into ions and electrons.
The ideal plasma gas is molecular,has a
high thermal conductivity, is easily ionized
and has a great molecular weight. Com-
pressed air is suitable for plasma gas,
however, as it contains oxygen the torch
has to be of a special design.
fig. 2
Publicité
