Segmented Burner Assembly for Flame Stability
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Solution Overview
Problem
Existing burner assemblies for high-temperature furnaces face challenges in maintaining flexibility across a wide range of firing rates, leading to issues such as 'lazy' flames at low rates and flame control difficulties at high rates, which can result in hot spots and furnace damage.
Innovation Solution
A burner assembly with at least two fuel gas canals and one oxidant canal, where the fuel and oxidant streams converge downstream, featuring a fuel gas distributor that controls the flow to inner and outer passages, allowing simultaneous and even control of the flame length and momentum, thus adapting to varying firing rates without moving parts exposed to high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional burner assembly operates at low firing rates, then fuel consumption is reduced, but the flame becomes 'lazy' and lifts towards the furnace crown causing hot spots
Solution Approach 1:
The burner assembly is segmented into multiple fuel canals (at least two) with different orientations - some canals are horizontal and others are inclined at angles between 10-45 degrees. This segmentation allows different fuel streams to be injected at varying angles, creating a more stable flame structure that prevents lifting even at low firing rates, while maintaining control across the full productivity range.
2Productivity
If a conventional burner assembly operates at high firing rates, then heat output is increased, but flame control becomes difficult and the flame may damage the opposite furnace wall
Solution Approach 1:
Different fuel canals are assigned different local qualities through their specific orientations - horizontal canals provide a baseline flame structure while inclined canals extend the flame in specific directions. This local differentiation of fuel injection characteristics allows the flame to be controlled and directed even at high firing rates, preventing damage to furnace walls while maintaining high heat output.
3Object-generated harmful factors
If substantially pure oxygen is used instead of air as the oxidant, then NOx emissions are reduced by up to 90%, but the flame temperature increases creating regions where NOx formation may proportionally increase
Solution Approach 1:
The oxidant supply is segmented into multiple canals with different orientations, matching the segmented fuel injection structure. This allows for controlled mixing of oxygen with the fuel streams at different locations and temperatures within the combustion zone, reducing peak temperatures in any single region while maintaining overall combustion efficiency and minimizing both global and local NOx formation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances flexibility and reliability by maintaining even heat distribution and flame stability across a wider range of firing rates, preventing hot spots and furnace damage while allowing the use of low calorific value fuels, thereby improving the quality of products and extending furnace lifespan.
Implementation Method 1
combustion of the fuel with the oxidant generates reduced quantities of nitrogen oxides (NOx)
Implementation Method 2
The transfer of energy from the flames to the material to be heated or melted results from the combination of convection at the surface of the material
Implementation Method 3
radiation to the surface or into the material, if the material is transparent to the radiation
Data Source
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AI summary
Variable momentum burner assembly for separately injecting fuel gas and oxidant in a combustion zone, comprising at least two fuel gas canals (100), at least one oxidant canal and a fuel gas distributor (110), whereby the at least two fuel gas canals comprise an inner fuel-conducting passage (101) forming an inner fuel gas outlet and an outer fuel-conducting passage (102) forming an outer fuel gas outlet, said inner and said outer fuel-conducting passages being coaxially arranged; and whereby said fuel gas distributor comprises a first fuel gas chamber (111) in fluid connexion with the inner fuel-conducting passage of the at least two fuel gas canals and a second fuel gas chamber (112) in fluid connexion with the outer fuel-conducting passage of the at least two fuel gas canals.