Burner Flame Stabilization via Flow Velocity Ratio Adjustment
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Solution Overview
Problem
Existing burners with air nozzles for inner flame-holding have complex configurations and require additional air supply systems, making stable ignition and flame holding challenging.
Innovation Solution
A burner design featuring an inner gas nozzle, a fuel supply nozzle, an outer gas nozzle, and a flow-velocity-ratio adjustment apparatus, with inner and outer flame holders, and intermediate flame holders to stabilize ignition and flame holding in both inner and outer flame holding regions without the need for an inner flame-holding air nozzle, using a simple configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an air nozzle for inner flame-holding is provided to feed high-temperature gas into fluid mixture, then flame holding performance is enhanced, but the configuration of the burner becomes more complex and an additional air supply system is required
Solution Approach 1:
The patent combines the inner flame holder and outer flame holder into a single integrated structure. The inner flame holder is positioned within the outer flame holder, and both work together to stabilize the flame without requiring a separate air nozzle for inner flame-holding. This merging of functions reduces the overall complexity of the burner configuration while maintaining effective flame holding performance.
Solution Approach 2:
The flame holders serve multiple functions: they stabilize the flame, create recirculation zones for heat retention, and guide the flow of combustion gases. By making the flame holders multi-functional, the patent eliminates the need for additional specialized components like an inner flame-holding air nozzle, thus reducing system complexity while maintaining reliability.
2Reliability
If multiple flame holders and flow adjustment apparatus are added to stabilize ignition and flame holding, then flame holding stability is improved, but the device complexity increases
Solution Approach 1:
The patent divides the flame holding function into two distinct but integrated components: an inner flame holder and an outer flame holder. Each is positioned at specific locations within the burner to create complementary recirculation zones. This segmentation allows for stable ignition and flame holding while keeping each individual component relatively simple in design.
Solution Approach 2:
The patent incorporates a flow-velocity-ratio adjustment apparatus that allows dynamic control of the gas flow velocities from the inner and outer nozzles. This dynamic adjustment capability enables optimization of flame holding stability under varying operating conditions without requiring multiple fixed-configuration flame holders, thus balancing stability with structural simplicity.
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 stabilizes ignition and flame holding in both inner and outer flame holding regions by adjusting flow velocities and enhancing circulation eddies, reducing complexity and the need for additional air supply systems.
Implementation Method 1
the inner flame holder contracts the flow of the inner combustion oxygen containing gas and thereby the inner circulation eddies are more easily formed between the discharge flow of the inner combustion oxygen containing gas and the discharge flow of the fluid mixture
Implementation Method 2
the outer flame holder deviates the discharge flow of the outer combustion oxygen containing gas from the axis so that the flow of the outer combustion oxygen containing gas spreads out, and thereby the outer circulation eddies are more likely to be formed between the discharge flow of the outer combustion oxygen containing gas and the discharge flow of the fluid mixture
Implementation Method 3
a flow-velocity-ratio adjustment apparatus configured to adjust a relative flow velocity ratio of a discharge flow velocity of the inner combustion oxygen containing gas to a discharge flow velocity of the outer combustion oxygen containing gas
Implementation Method 4
high-temperature gas can flow along the intermediate flame holders from the outer flame holding region toward the inner flame holding region. Accordingly, it is possible to increase temperature of the inner flame holding region
Data Source
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AI summary
A burner equipped with: an inside gas nozzle extending along an axis line while surrounding that axis line and capable of supplying to a furnace an oxygen-containing gas for inside combustion; a fuel supply nozzle that, when viewed in the direction along the axis line, surrounds the inside gas nozzle, and is capable of supplying to the furnace a fluid mixture of a solid powder fuel and a carrier gas; an outside gas nozzle that, when viewed in the direction along the axis line, surrounds the fuel supply nozzle, and is capable of supplying to the furnace an oxygen-containing gas for outside combustion; and a flow speed ratio adjustment mechanism capable of adjusting the relative flow speed ratio of the spray flow speed of the oxygen-containing gas for inside combustion and the spray flow speed of the oxygen-containing gas for outside combustion. Downstream from the outlet of the fuel supply nozzle, flame-holding regions are formed in the sprayed flow of the fluid mixture, these regions being formed respectively on the side of the sprayed flow of the oxygen-containing gas for inside combustion and on the side of the sprayed flow of the oxygen-containing gas for outside combustion.