Introduction to Thermal Lance

A thermal lance,oxygen lance or combustion rod is a tool that heats and melts steel in the presence of pressurized oxygen to produce very high cutting temperatures.It consists of a long steel pipe filled with alloy steel rods used as fuel;these are sometimes mixed with aluminum rods to increase heat output.

Operation

One end of the tube is placed on a stand,and oxygen is delivered through the tube.The distal end of the tube was preheated and ignited with an oxyacetylene torch.Produces an intense stream of flaming steel at the work end for fast cutting through thick materials,including steel and concrete.The tube is consumed by the process within minutes.

Application 

Typically used as a heavy-duty removal tool,thermal spray guns are also used to remove stuck shafts from heavy machinery without damaging bearings or shaft housings.This technique is often used on the pin shafts of large equipment such as cranes,ships,bridges and sluices. Additionally,thermal lances are used to clean the bottom of steel pans,where a layer of slag and iron can build up during operation.

How it works

Steel wool can burn at atmospheric (20%) oxygen concentrations because of its high surface area to mass ratio and relatively low mass,which prevents heat from being dissipated in most materials.Steel wool burns faster when the concentration of oxygen is increased.Burning steel wool just rapidly oxidizes iron to Fe

2O3;Thermal lances use steel rods that burn with a sufficiently high supply of concentrated oxygen.Operating temperatures for thermal spray guns vary by environment.Some estimates put the maximum temperature at 4500 °C (8130 °F),while others calculate it at 2730 °C (4950 °F).

Alternative fuels

Thermal spray guns have been constructed to demonstrate the use of food products (including bacon and dried pasta) instead of steel rods as fuel;the supply of pure oxygen is more important to drive rapid oxidation than the fuel being burned.