An oxy-acetylene torch harnesses the intense heat generated by burning acetylene gas with pure oxygen. This tool precisely mixes these two gases for controlled combustion, creating an exceptionally hot flame used across various industrial and artistic applications.
Torch Temperatures
An oxy-acetylene flame can reach remarkably high temperatures, typically ranging from 3,100°C to 3,500°C (approximately 5,600°F to 6,330°F). This makes it one of the hottest fuel gas flames available. For context, a common propane-air flame burns at about 1,980°C (3,590°F), and an oxyhydrogen flame reaches around 2,800°C (5,072°F).
Combustion Chemistry
The extreme heat of an oxy-acetylene torch stems from the chemical reaction between acetylene (C2H2) and pure oxygen. This highly exothermic combustion reaction produces carbon dioxide and water, releasing a substantial amount of energy.
The use of pure oxygen, rather than air, is a key factor in achieving such intense temperatures. Air contains inert nitrogen, which absorbs heat during combustion, diluting the flame and lowering its temperature. Pure oxygen eliminates this diluting effect, concentrating more combustion energy within the flame.
The torch’s design ensures optimal mixing of the gases, precisely controlling the oxygen-to-acetylene ratio. This allows for efficient and complete combustion, generating maximum heat at the flame’s inner cone and maximizing energy transfer to the workpiece.
Industrial Applications
The intense heat of an oxy-acetylene torch makes it invaluable across numerous industrial applications. One use is in welding, where the flame heats metal pieces to their melting point, allowing them to fuse together, often with a filler material. While modern arc welding has largely replaced oxy-acetylene for many industrial tasks, it remains a common choice for metal artwork, small-scale repairs, and situations without electricity.
Oxy-acetylene torches are also widely employed for cutting metals, particularly thick steel. The process involves preheating the metal with the flame, then introducing a high-pressure stream of pure oxygen. This oxygen jet reacts with the hot metal, causing it to rapidly oxidize and be blown away as dross, creating a clean cut.
Brazing is another significant application, joining two metal pieces using a filler metal that melts at a lower temperature than the base metals. The torch heats the joint, and the molten filler material flows into the gap through capillary action, creating a strong bond without melting the base metals themselves.
The torch is also used for general heating purposes:
Bending or shaping metal.
Loosening rusted or seized components.
Localized heat treatment processes.