The amount of heat energy transferred from an acetylene torch flame to the metal being melted depends on several factors, including the efficiency of the torch, the distance between the flame and the metal, and the thermal properties of the metal itself. It is challenging to provide an exact percentage as it can vary in different scenarios. However, I can offer some insights into the heat transfer process.
When an acetylene torch flame comes into contact with the metal, heat is transferred through a combination of conduction, convection, and radiation. Here's a general breakdown of these heat transfer mechanisms:
Conduction: Conduction is the transfer of heat through direct contact between two objects. When the flame touches the metal, some heat is conducted into the metal, causing it to heat up. The amount of heat transferred through conduction depends on factors such as the temperature difference between the flame and the metal and the thermal conductivity of the metal.
Convection: Convection is the transfer of heat through the movement of fluids or gases. In the case of an acetylene torch flame, hot gases are generated, and some of these gases come into contact with the metal's surface. This convective heat transfer can contribute to heating the metal.
Radiation: Radiation is the transfer of heat through electromagnetic waves. The flame emits thermal radiation, which can be absorbed by the metal's surface, leading to its heating. The amount of heat transferred through radiation depends on factors such as the temperature of the flame and the emissivity of the metal.
However, it's worth noting that not all the heat energy released by the flame is efficiently transferred to the metal. Some heat may be lost to the surrounding environment due to factors like air movement, heat dissipation through the torch structure, and incomplete combustion of the acetylene gas.
To maximize the heat transfer efficiency, it's important to ensure proper torch technique, maintain an appropriate distance between the flame and the metal, and use appropriate flame settings for the specific metal being melted.