Inside the burner assembly of nearly every oil-burning boiler’s fire side, you’ll find a piece of technology called the “burner oil gun”. While it doesn’t shoot more than a few millimeters, it’s a crucial weapon in the fight against inefficiency. To understand its value, we have to understand a few things about how boilers work, specifically oil-fired boilers, and the history behind them.
ROLLING COAL
Early industrial boilers of the 1800s and early 1900s were fired by coal. It was cheap, abundant, and provided consistent heat. Unfortunately, because there were no methods for cleaning coal exhaust back then, coal was a pretty dirty fuel. Eventually, alternatives for coal began to appear on the market, and one of the most promising was fuel oil. Early use in marine applications proved that fuel oil could be a reliable way to fire steam boilers at sea for several reasons. First, because it had a higher energy density than coal, meaning you could get more steam per ton of oil than you could for the same weight of coal. Second, because it was a fluid, fuel oil was easier to store on board ships without wasted space. It was also easier to handle, because it could be made to flow where it was needed without requiring manpower to shovel it.
OIL LANDS
During the early 1900s, the petroleum industry really came into its own, which created an abundance of fuel oil. After proving itself as a successful boiler fuel in naval applications, it’s not a surprise then that fuel oil began to find its way into land-based applications like factories and locomotives. Early fuel oil delivery systems relied on gravity to keep the burners supplied, which was a reliable method but not terribly efficient when it came to fuel consumption. More oil was burned than was necessary, which not only created waste, but it also limited the heat output of the burner.
GUN’S OUT, FUN’S OUT
In the middle of the 20th century, oil-burning technology began to advance with the advent of atomization. As it turns out, when fuel oil is turned into a fine mist, it can burn hotter, faster, and more efficiently. This is because there’s more surface area of oil exposed to more oxygen, creating more efficient combustion. Early atomization methods included forcing the oil through a small aperture using mechanical pressure, and vaporization using compressed air. Both of which have evolved and combined into the technology we know today as the burner oil gun.
A burner oil gun’s purpose is to maintain the most efficient mixture of fuel oil and air, so that every last bit of energy can be extracted from the oil. To understand how it all works, let’s follow the journey of the oil from the supply line until the moment of combustion.
The oil flows under pressure to a nozzle in the burner oil gun to be atomized. While nozzles are a very popular method of atomization, fuel oil may also be atomized by blasting it with steam or compressed air.
Meanwhile, as the oil heads through the atomization process, forced air is introduced to the burner gun using draft fans. As the air flows, turbulence is introduced to it to make it burn more efficiently. As the atomized oil and turbulent air flow through the burner oil gun, they mix together as they flow over specially shaped vanes designed to blend them in the most efficient way possible. Once the atomized-oil-and-air mixture is properly blended, it is ignited by the burner using an electronic ignition system, normally with a gas pilot, then it begins the process of heating the water to make steam. In a fire-tube boiler, this means creating hot combustion gases that will pass through the pressure vessel. In a water-tube boiler, steam production means heating the tubes through which water flows until it changes phase into steam.
The key to efficient boiler operation is to make sure your burner oil guns are properly adjusted and tuned. That takes a professional with years of experience, and that’s what WARE is all about. If you need maintenance or adjustment of your boiler, we’re here to help. If you’re in the market for a new or rental boiler, we’ve got you covered there, too. We also operate the nation’s largest online parts and supplied website, BoilerWarehouse.com. In fact, whatever you need, we’re always here to help. Just let us know.