Boiler burners are core functional components in the actual design of combustion systems, including gas fuel distribution, fuel preparation, combustion control and furnace design. The development of industrial gas and boiler burners has undergone many changes in the past 50 years, making boiler systems more efficient and durable.
Modern industrial boilers have made significant progress in achieving multi-fuel flexibility, low emissions, high turndown ratios, long life, and stable operation of burner systems through new boiler technologies.
Advanced industrial boiler control technology and mature combustion performance have greatly improved boiler efficiency and promoted industrial operation and application. The following describes the changes in boiler burner systems over the past 50 years.
Basic Draft Burners: 1960-1970
From the most basic burners of the 1960s and 1970s to today's more modern and efficient low NOx burners, the boiler industry has undergone tremendous changes. Although burner design has changed over the years, achieving its maximum efficiency and safety remains a key design element even with new boiler technology. Another area of major change is the use of draft burners.
What is a draft burner?
In industrial boiler systems, plant service engineers use modulating air burners to adjust and supply precise amounts of air for efficient combustion. Basic modulating air burners in the past were equipped with one or two sets of adjustable louver-style dampers or vanes to optimize or control the rotation of the combustion air before it mixes with the fuel.
Too little air can lead to incomplete combustion, ash accumulation, smoke and flame instability. Too much air can reduce overall combustion efficiency by removing heat from the furnace space, which may increase sulfur deposition and "white smoke".
Service engineers also use modulating air burners as a convenient tool to control flame shaping or adjust flame width. These burners are widely used for oil and gas fuels. For gas, modulating air burners have multiple lances and even a center lance or a ring gas fitting. For oil, a gun burner or atomizer must be inserted in the center of the modulating air burner.
Changes in burner design
Over the years, as burner design has changed, more efficient burners have emerged that do not use the convection louver-style dampers of venturi-type burners. Despite advances in new boiler technology, most burners still require flame stabilization devices such as burner swirlers or diffusers.
Today, modern modulating air burners are used in industrial boilers to precisely control and distribute large volumes of combustion air and are designed with safety and efficiency in mind.