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

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【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-NOx burners for heating furnaces. Selection and design of burners that reduce nitrogen oxides (NOx) in 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 lean-fuel zone); the smoke generated from this flame is drawn out through the firebox vents, which is then used to ignite the second stage of fuel, resulting in a secondary flame (an oxygen-deficient 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 various factors such as furnace temperature (which determines whether a low-NOx or ultra-low-NOx type should be chosen), the operational flexibility of the installation (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 along the wall), and the properties of the fuel.