Burner Air Diverter and Recirculation for Stable Low-NOx Flames
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing burners face challenges in controlling NOx emissions and maintaining stable flame modes across varying air-oxygen mixtures, especially during low thermal demand periods and high temperatures, while achieving uniform heating and high production rates.
Innovation Solution
A burner design featuring an oxidant feed passage, a fuel feed passage surrounded by an air feed, and a movable air flow diverter, which creates a gas recirculation region to stabilize combustion and control NOx emissions, allowing operation from pure air to pure oxygen with flame and flameless modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If oxygen concentration is increased to improve flame temperature and production rates, then productivity increases, but NOx emissions increase due to enhanced thermal NOx formation
Solution Approach 1:
The combustion process is divided into two stages: primary combustion in a fuel-rich environment with limited oxygen, and secondary combustion with supplemental oxidant. This segmentation allows the fuel to partially react first, elongating the flame and radiating heat before final oxidation, thereby reducing peak temperatures and thermal NOx formation while maintaining high production rates
Solution Approach 2:
Different regions of the combustion process are given different oxygen concentrations - the primary combustion zone operates fuel-rich with limited oxygen to suppress NOx, while the secondary zone introduces supplemental oxidant for complete combustion. This local differentiation allows simultaneous achievement of low NOx emissions and high productivity
2Loss of energy
If air is replaced with pure oxygen to reduce combustion product volume and improve thermal efficiency, then thermal efficiency improves, but flame stability deteriorates during low thermal demand periods
Solution Approach 1:
The burner system dynamically adjusts the oxidant mixture composition based on thermal demand. During high demand periods, pure oxygen or high oxygen concentration is used for maximum efficiency. During low demand periods, the system transitions to air or lower oxygen concentrations to maintain stable flame operation, allowing the system to adapt to varying operational conditions
3Object-generated harmful factors
If staging technology is used to reduce NOx emissions, then NOx formation decreases, but device complexity increases due to multiple oxidant supplies
Solution Approach 1:
The burner is designed with multi-functionality to operate in multiple modes (flame mode and flameless mode) and accept various oxidant compositions (air, oxygen-enriched air, pure oxygen). This universal design allows the system to achieve NOx reduction through operational flexibility rather than requiring complex additional hardware for each control function
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
The burner effectively reduces NOx emissions and maintains stable combustion across different oxidant ratios, enabling uniform heating and high production rates by adjusting air flow to control flame stability and temperature distribution.
Implementation Method 1
Burner for the combustion of fuels
Implementation Method 2
a recirculating flow pattern that stabilizes the flame
Implementation Method 3
heat is radiated from the flame
Data Source
AI summary
A method of generating a flame from combustion of a fuel, includes moving an oxidant feed through an oxidant feed passage; moving a fuel feed through a fuel feed passage surrounding the oxidant feed passage; moving an air feed containing oxidant within an air feed region surrounding the fuel feed passage along the fuel feed passage; creating a gas recirculation region immediately downstream from the air feed and the fuel feed passage; diverting the air feed for proportioning the air feed around the fuel feed passage for controlling flame stabilization in the gas recirculation region; and igniting a resulting gas mixture.