Flame Temperature vs BTUs, What is more important for torch cutting?

Among the fuel gases commonly used, propane/propylene typically produces the most BTUs (British Thermal Units) when mixed with pure oxygen. Propane/propylene has a higher heating value compared to acetylene, meaning it releases more energy per unit of fuel consumed.

Here is a rough comparison of the approximate heating values for these gases:

1. Acetylene: The heating value of acetylene is around 1,300-1,500 BTUs per cubic foot.

2. Propane: Propane has a heating value of approximately 2,500-2,800 BTUs per cubic foot.

3. Propylene: Propylene generally has a heating value similar to propane, ranging from around 2,500-2,800 BTUs per cubic foot.

More BTUs (British Thermal Units) per cubic foot generally indicate a higher heat content or heat output of a fuel. BTUs are a unit of measurement used to quantify energy content or heat energy. When comparing fuels, a higher BTU value per cubic foot means that the fuel has a greater potential to release heat energy when burned.

For example, if you have two fuel gases, A and B, and fuel A has a higher BTU per cubic foot than fuel B, it indicates that fuel A has a higher heat content and can release more heat energy per unit volume when burned.

The flame temperature and BTUs (British Thermal Units) are two different concepts related to the characteristics and energy output of a flame:

1. Flame Temperature: Flame temperature refers to the actual temperature of a flame, typically measured in degrees Celsius or degrees Fahrenheit. It represents the heat energy released by the combustion process. The flame temperature depends on various factors such as the fuel type, oxygen supply, burner design, and combustion conditions. Higher flame temperatures generally indicate a more intense and hotter flame.

2. BTUs (British Thermal Units): BTUs are a unit of measurement used to quantify energy content or heat energy. It represents the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. In the context of fuel gases, BTUs are often used to indicate the heating value or energy content of a fuel. It measures the potential energy released when the fuel is burned completely.

While flame temperature and BTUs are related to heat energy, they are distinct concepts. Flame temperature directly measures the temperature of the flame, while BTUs quantify the energy content or heat release potential of a fuel. It’s important to note that the flame temperature does not directly correlate with BTU measurements, as other factors, such as the burner design and combustion efficiency, can affect the heat transfer and utilization of the energy content.

In summary, flame temperature refers to the actual temperature of a flame, while BTUs measure the energy content or heat potential of a fuel. Both are important in understanding and analyzing combustion processes and heat transfer but represent different aspects of the overall system.

Conclusion: BTU's are more important! we need to heat metal as quickly as possible to a super heated state so that an exothermic reaction can commence.