Description of equipment and implementation
Thermite welding of railways rails

• The batch is mass-produced on a multi-dosing machine, which fills plastic bags with the required quantities of components.

• These bags, duly sealed, are transported along the track with the reaction crucibles and sealing molds to be attached to the rail ends to be welded.

• The charge is emptied into the crucible, which is equipped with a taphole at the bottom, sealed by a refractory that automatically melts at a predetermined temperature (around 2,300°C). A refractory cap covers the charge after it has been ignited by a firebrand providing the heat to activate the reaction. The reaction propagates very rapidly, in the order of 20 to 30 s, and the mold is opened for casting in an average of 24 s (figure 2).