Fuel Oil; Burner
FUEL OIL BURNERS
By Mark Butterfield
March 09
INTRODUCTION
The history of burners dates back to the early shipping days, when fuel oil first started replacing coal as the ships’ primary fuel source.
Since then, burner designs and construction have come a long way, but the principles behind their operation has remained the same.
All makes and types of burners have two things in common
They need to atomise the fuel They need to mix the fuel with the air needed for combustion
Why do we want to use a burner?
To convert water into steam.
To heat thermal oil
For direct firing in cooking and oxidising
To provide heat to dry products
Why is it necessary to atomise fuel?
Even though fuel oil is classified as a flammable liquid, most fuels will not burn easily in a liquid state. If you were to drop a lit match in a container of fuel oil, it would PROBABLY go out almost immediately (don’t try this!). In order for fuel oil to burn, it must first be transformed from a liquid to a vaporised state ~ atomised. Atomisation increases the exposure of the fuel to the oxygen in the air; this promotes combustion.
A nozzle rated at 0.60 US gallons per hour can generate as many as 50 million droplets of oil in an hour.
EFFECTS OF BAD ATOMISING
If atomisation is incomplete, the droplet sizes are too large for complete combustion. The larger droplets will escape the flame only partially burnt. This can usually be seen as “fire flies” when looking at the flame. This will not only result in a poor flame, but also soot deposits being formed inside the combustion chamber. In addition the combustion plant’s efficiency will reduce causing excessive fuel usage for the required energy output.
There are generally four types of burners, each of which atomise fuel in different ways.
Pressure Jet Air / Steam Atomised Rotary Cup Low Pressure Air Atomising
Pressure Jet Burner
The most common types of pressure jet burners in our industry
By Mark Butterfield
March 09
INTRODUCTION
The history of burners dates back to the early shipping days, when fuel oil first started replacing coal as the ships’ primary fuel source.
Since then, burner designs and construction have come a long way, but the principles behind their operation has remained the same.
All makes and types of burners have two things in common
They need to atomise the fuel They need to mix the fuel with the air needed for combustion
Why do we want to use a burner?
To convert water into steam.
To heat thermal oil
For direct firing in cooking and oxidising
To provide heat to dry products
Why is it necessary to atomise fuel?
Even though fuel oil is classified as a flammable liquid, most fuels will not burn easily in a liquid state. If you were to drop a lit match in a container of fuel oil, it would PROBABLY go out almost immediately (don’t try this!). In order for fuel oil to burn, it must first be transformed from a liquid to a vaporised state ~ atomised. Atomisation increases the exposure of the fuel to the oxygen in the air; this promotes combustion.
A nozzle rated at 0.60 US gallons per hour can generate as many as 50 million droplets of oil in an hour.
EFFECTS OF BAD ATOMISING
If atomisation is incomplete, the droplet sizes are too large for complete combustion. The larger droplets will escape the flame only partially burnt. This can usually be seen as “fire flies” when looking at the flame. This will not only result in a poor flame, but also soot deposits being formed inside the combustion chamber. In addition the combustion plant’s efficiency will reduce causing excessive fuel usage for the required energy output.
There are generally four types of burners, each of which atomise fuel in different ways.
Pressure Jet Air / Steam Atomised Rotary Cup Low Pressure Air Atomising
Pressure Jet Burner
The most common types of pressure jet burners in our industry