The earliest gas burners that were simply open ends of pipe are referred to as what type of flame burners?

The earliest gas burners, which were essentially open ends of pipe, are classified as luminous or yellow flame burners. This designation comes from the nature of the flame they produce. When gas is burned in these types of burners, the combustion process is incomplete, leading to a yellow, luminous flame characteristic. This yellowish coloration is primarily due to the presence of carbon particles that are not fully combusted, which glow when heated.

Luminous flame burners were common in older gas appliances because they were simple to construct and used in early gas lighting. The design allowed for a steady but inefficient burn, which produced visible light, making it suitable for illumination purposes.

In contrast, other types of burners, such as blue flame burners, represent a more efficient combustion process where natural gas is mixed with the appropriate amount of air, leading to clean, complete combustion and a blue flame. Flame-less options refer to technologies that don't rely on traditional combustion processes, such as electric heaters or infrared devices. Understanding the distinction between these types of burners and their flame characteristics is essential for comprehending how gas appliances have evolved over time.