What is a pressurized (pressure type) lantern?
Lantern Guide
How kerosene lanterns work
Lanterns, which use liquid fuels such as kerosene or lamp oil to provide light, can be broadly divided into two types. One is the "pressurized lantern," which applies pressure to a fuel tank to turn the kerosene into a gaseous form that emits a dazzling light, and the other is the "lamp," which uses a wick to draw up fuel and create a flame. Lanterns are portable, wind-resistant lanterns, while stationary interior lanterns are lamps.
What is a pressurized (pressure type) lantern?
The invention of the mantle
In 1885, Auer-Welsbach discovered that cotton threads soaked in a thorium solution would glow white when held over a burner flame. After further research, he found that they were even more luminous when immersed in a mixture of thorium and cerium nitrates. When placed over an open gas flame, they became six times more luminous. When the "mantle" was lit, the woven cotton burned away, leaving behind a hard oxide of thorium and cerium. Though fragile, the invention was revolutionary and has been used all over the world, especially in street lighting.
The invention of the kerosene lantern
Soon, the idea of using liquid fuel for easy portability was proposed, and at the end of the 19th century, lanterns using alcohol and kerosene were developed, which pressurized the fuel tank, heated and evaporated the liquid fuel, and produced gaseous fuel. These were called "Pressure Lanterns", and the "VAPALUX" invented by Willis & Bates is one of the few kerosene lanterns that still remain today.
How kerosene lanterns work (Vapalax)
Let's take the "Vapalax" lantern as an example. Simply put, it is a device that vaporizes liquid kerosene and creates flammable gas by mixing it with air. The (pressurized) fuel tank is compressed and pressurized by a hand pump, and is used to push the liquid kerosene up into the vaporizer (called a vaporizer or generator).
(Preheating) Before lighting the mantle, the liquid kerosene must first be turned into gas in the vaporizer. To do this, the alcohol poured into the preheating cup is burned to heat the vaporizer sufficiently. This is called preheating.
(Evaporation of fuel) Once the gasified kerosene is ignited, the liquid kerosene in the vaporizer continues to vaporize due to the heat emitted from the mantle. The liquid kerosene boils and evaporates at approximately 250°C (480°F). The gasified kerosene increases in temperature and spurts out of the nipple at the top of the vaporizer at a speed almost close to the speed of sound.
(Mixing with air - Combustion) Compressed gaseous kerosene expands all at once and mixes with the air sucked in from the air button in the small space inside the burner. The completely mixed clean gas is sprayed out from the nozzle at the bottom of the burner, and hits the mantle while burning, producing a dazzling white glow.
This basic mechanism is common to all pressurized lanterns such as Petromax and Coleman. Understanding this will be of great help in maintaining your lantern.
