Pre-mix Burner Jet Pump for Flue Gas Recirculation
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Solution Overview
Problem
Current methods for flue gas recycling in fossil fuel-fired combustion applications increase system complexity and costs, requiring additional equipment and maintenance due to the need for larger fans and additional piping to handle recycled flue gas, which is costly and prone to fouling.
Innovation Solution
A pre-mix burner with a combustion air driven jet pump that uses a combustion air nozzle with a smaller outlet diameter to create negative pressure, allowing flue gas to be drawn into the combustion air stream without increasing piping or fan components, thereby reducing system complexity and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If flue gas recycling is implemented using traditional methods with additional piping and enlarged combustion air fan, then NOx emissions are reduced, but system complexity and capital cost increase
Solution Approach 1:
The patent combines the flue gas recycling function with the existing combustion air delivery system by integrating a flue gas inlet and mixing chamber into the combustion air tube assembly. The combustion air fan simultaneously delivers both combustion air and recirculated flue gas through the same piping system, eliminating the need for separate flue gas transport equipment and reducing system complexity while maintaining effective NOx reduction
Solution Approach 2:
The combustion air fan is designed to perform multiple functions: it delivers combustion air to the burner and simultaneously recirculates flue gas back to the combustion zone. This multi-functionality eliminates the need for dedicated flue gas recirculation fans and piping, reducing capital cost and system complexity while achieving the desired emissions reduction
2Object-generated harmful factors
If flue gas recycling is implemented with enlarged combustion air fan, then NOx emissions are reduced, but operating cost and energy consumption increase
Solution Approach 1:
The patent combines the flue gas recycling function with the existing combustion air delivery system by integrating a flue gas inlet and mixing chamber into the combustion air tube assembly. The combustion air fan simultaneously delivers both combustion air and recirculated flue gas through the same piping system, eliminating the need for separate flue gas transport equipment and reducing system complexity while maintaining effective NOx reduction
Solution Approach 2:
The combustion air fan is designed to perform multiple functions: it delivers combustion air to the burner and simultaneously recirculates flue gas back to the combustion zone. This multi-functionality eliminates the need for dedicated flue gas recirculation fans and piping, reducing capital cost and system complexity while achieving the desired emissions reduction
3Object-generated harmful factors
If flue gas is recirculated through existing combustion air fan, then NOx emissions are reduced, but fan fouling and maintenance requirements increase
Solution Approach 1:
The patent extracts the flue gas recirculation function from the combustion air delivery system by providing a separate flue gas inlet that draws flue gas directly into the combustion zone bypassing the combustion air fan. This separation prevents the fan from handling corrosive flue gas, eliminating fouling issues and maintaining fan reliability while still achieving effective flue gas recycling for NOx reduction
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 solution effectively reduces NOx emissions and maintains thermal efficiency while minimizing equipment upgrades and operational expenses by integrating flue gas recycling into the existing burner design without additional piping or fan upgrades.
Implementation Method 1
uses a combustion air nozzle with a smaller outlet diameter to create negative pressure, allowing flue gas to be drawn into the combustion air stream
Implementation Method 2
A jet pump discharge is connected to a burner housing to deliver a mixture of combustion air, fuel gas, and flue gas
Data Source
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AI summary
The pre-mix burner assembly includes a jet pump comprising a suction chamber, a flue gas inlet, and a combustion air tube with a combustion air nozzle. The combustion air inlet includes a combustion air tube with a tapered nozzle, and it is connected to a combustion air fan. The flue gas inlet is connected to the suction chamber and the combustion air fan. The suction chamber surrounds the combustion air tube, and it has a jet pump nozzle with a discharge. The assembly includes a fuel gas inlet connected to the combustion air tube. The combustion air and fuel gas mixture exits the combustion air nozzle creating a negative pressure in the suction chamber and drawing flue gas into the suction chamber. The assembly includes a mixing tube positioned downstream of the jet pump discharge, and a burner block connected to an outlet of the mixing tube.