【3D Process Flow】Summary Post--Selection and Design of Low-NOx Burners for Heating Furnaces

Thread Content

【3D Process Flow】Summary Post – Useful for learning about the process flow: https://bbs.hcbbs.com/thread-5711616-1-1.html ---------------------------------------------------------- Selection and design of low-nitrogen oxides (NOx) burners for heating furnaces. The core technology involves the use of staged combustion of fuel and air, achieving low NOx emissions through a flat flame burner design attached to the wall. The burner consists of a firebox brick, staged combustion (the inner nozzle being the first stage and the outer nozzle the second stage), a pilot light, a cylinder, and an air regulation mechanism. Its working principle relies on the special structure of the firebox bricks – flat, constricted flue channels, inclined surfaces attached to the wall, and horizontal/vertical smoke vents – in combination with staged fuel injection: The first stage of fuel mixes with air to form a primary flame (a fuel-lean zone), and the smoke generated from this is discharged through the firebox vents; this smoke is then used to ignite the second stage of fuel, resulting in a secondary flame (an oxygen-lean zone). Ultimately, these flames combine to form a tertiary flame. This multi-stage segmented flame design prevents heat concentration and reduces the peak flame temperature, thereby effectively suppressing the formation of heat-induced NOx. The selection process requires taking into account a variety of factors, including furnace temperature (which determines whether a low-NOx or ultra-low-NOx type should be chosen), the operational flexibility of the equipment (for example, hydrogenation units require a larger operating range), flame shape (a flat flame that adheres to the furnace wall helps to balance the heat distribution on that wall), and the properties of the fuel.