Tweco SLICE - Manual (Page 3)

3
PRINCIPLES OF
OPERATION
Genera l
SLICE Exothermic Cutting uses heat
from a chemical reaction between a
consumable steel rod and oxygen
flowing through the rod. Test data
show that little or no oxygen remains.
The oxygen not used in the reaction
blows the molten material out of the
cut area. This action creates the kerf
that allows cut progression.
Exothermic cutting can be used with
or without power. Without power, the
heat from the reaction alone will
make the cut. With power, an
electrical arc from a welding power
source increases the heat from the
reaction. These differences will be
discussed in detail later.
Both methods use the same
consumable rod. This rod is inserted
into the torch and locked into place.
The oxygen lever on the torch is
depressed and the arc, to start the
burn, is established. Once the rod
burn has begun, the rod tip should be
placed at the cut area with slight
contact between the tip of the rod and
the work piece.
The burning rod tip must be kept in
slight contact with the work piece to
achieve the most efficient cut. Rods
used in exothermic cutting can be
consumed without any cutting taking
place. Tip contact tells the operator
that the most intense heat from the
rod is in direct contact with the
workpiece, ensuring the best cutting
speeds.
FIGURE 1 How the Torch Works
Cutting Without Power
Cutting without power is cutting with
the heat from the reaction between
the rod and the oxygen. This type of
cutting is done by igniting the rod off
a spark supplied by a 12-volt battery
or by a welding power source capable
of delivering a 100-amp surge.
Once this spark has ignited the rod,
the electrical path is broken and the
heat of the reaction melts the material
and cuts it.
Cutting without power can be done in
remote areas. Bulky power sources
and support equipment is not needed.
Cutting With Power
Cutting with power requires an
electrical arc from a welding power
supply and increases the heat
created exothermically. Almost all
constant-current welding power
supplies can be used in powered
exothermic cutting. Cutting with
power is faster than cutting without
power.
SLICE ROD
COLLET CHUCK
HEAD ASSEMBLY
COLLET NUT
CUTTING OXYGEN
OXYGEN LEVER
SHIELD
SPARK ARRESTOR
HANDLE