How to Select an Efficient Boiler Burner
A boiler burner produces flue gases that contain harmful pollutants, including nitrous oxide (NOx), which can cause acid rain and trigger respiratory ailments in humans. These gases can also contribute to greenhouse gas emissions. For this reason, boiler burners are subject to stringent regulations. The good news is that many boilers are designed to reduce the emissions of their fuel. Learn how to select an efficient boiler burner. Listed below are some benefits of boiler burners.
A boiler burner works by breaking fuel oil into fine droplets and atomizing it for combustion. To achieve atomization, the fuel is subjected to a pressure difference. The difference between the pressure in the fuel and air flowing through the burner controls the amount of atomization. As a result, it is important to maintain the nozzles to ensure efficient combustion. And remember to replace the fuel nozzles at regular intervals – if the oil doesn’t burn properly, they could be clogged.
Using a parallel positioning system to control the ignition of a boiler burner reduces the risk of a fire by eliminating the need for mechanical linkages. This eliminates the hysteresis that causes burners to operate lean or rich, leading to inefficient fuel use. Further, minimizing mechanical linkages allows the burner to operate in an optimal lean condition. If a fire is detected, a relief valve will vent the excess steam from the boiler.
In addition to setting the air and fuel proportion, a boiler control system controls the firing conditions by determining which fuel, air, and water to insert into the boiler. Often, this system will automatically adjust the fuel and air flow while maintaining the safe margin for excess air. With a well-tuned boiler burner, the CCS can maintain a steady combustion rate with little or no effort. Once the burner is running in a safe and efficient manner, the boiler can produce hot water with no worries.
The combustion process in a boiler is an essential part of the process of a boiler’s operation. Proper mixing of fuel and air ensures complete combustion, which is necessary for an efficient boiler. Proper combustion also determines the shape and direction of the flame. A boiler burner has a turndown ratio (or “turndown”), which is based on the maximum firing rate divided by the minimum controllable firing rate. Regardless of the fuel used, a boiler burner must be calibrated periodically and cleaned regularly.
Boiler burners can be set to use oil as well as gas. The latter is beneficial in the event that a gas supply is unavailable. Dual fuel boiler burners are designed to use both fuels, but have a separate facility for oil firing. When switching from one fuel to the other, the control panel must be switched to the appropriate fuel, and air settings are changed accordingly. In the case of a gas-fired boiler, a manual switchover may not be necessary.
If a boiler uses a power burner, it is important to consider the safety and efficiency of the system. Excess air in the combustion chamber causes the gasses to travel faster and cause the stack to heat up. Ultimately, this causes thermal-fatigue in the system. The image to the left shows a boiler with excess air. Notice the yellow spot near the rear of the boiler where the flame hits. If this is the case, it may be time to replace your boiler.