Why a Candle Flame Lightens a Dark Room More Effectively Than an LPG Flame
Have you ever pondered why a candle flame effectively brightens up a dark room, whereas an LPG flame doesn't? This difference primarily stems from the nature of the flames and the materials involved in their combustion. Let's delve into the details to understand why.
Understanding the Flames: Soot Production
A candle flame produces soot as it burns the wax, which is a hydrocarbon. Soot plays a crucial role in the light production, as it glows when heated. This soot contributes to the light emission, making the flame more visible and effective in illuminating a space.
Color Temperature and Light Emission
The candle flame has a lower color temperature, typically ranging between 1000 and 1500 Kelvin (K), giving it a warm, yellowish light. This hue is more efficient for illuminating a space because it emits a broad spectrum of light that our eyes can detect more effectively. Conversely, the LPG flame has a higher color temperature, around 1800 to 2000 K, and is often blue due to complete combustion. While this flame is highly efficient for heating, it emits less visible light compared to a candle flame.
Radiative Heat and Light Distribution
The candle flame radiates heat and light over a larger area due to its size and the nature of the combustion process. This larger diffusion creates a flickering effect that enhances visibility, making the candle flame more effective in lighting up a dark room. In contrast, the LPG flame is more concentrated, producing less diffuse light that makes it less effective at illuminating a larger area. The blue color of the LPG flame, although efficient for combustion, is less effective for general illumination.
Technical Insights: Candle vs. LPG Flame
Another intriguing aspect is the energy output of these flames. A lighted candle may take several minutes or even an hour to boil a glass of cold water, while an LPG burner can do this in a flash. This is because LPG provides many times more energy in terms of kilo-calories and joules than a candle.
In a lighted candle, it is the wick soaked in hot paraffin wax that burns, not the wax itself. The flash point of paraffin wax is quite high, and it does not burn by itself but aids in the burning process before being oxidized. If you place a candle near an LPG burner, the high temperature melts the wax, causing it to spread in a molten liquid form temporarily. The LPG, with a lower flash point, can burn by itself at room temperature, making it a more powerful energy source.
The LPG burner is designed to contain and direct optimum energy to a limited area at the bottom of the vessel it heats. This design creates a blue flame with minimal soot, making it an efficient heating source. If the LPG is provided to a device called a mantle in a regulated manner, it can produce light many times more than a lighted candle. Small LPG cylinders with regulators and provision for mantles are available in the market for use as emergency lanterns during power outages.
Technicality and Expertise
For a more detailed and technical analysis, you can refer to Quora for additional information.
Understanding the difference between the candle flame and the LPG flame not only provides insights but also highlights the efficiencies and purposes of each. Whether for lighting a room or generating heat, the choice of flame depends on the specific needs and desired outcomes.