Modulating Burner With Variable Combustion Area for Low Firing Rates
Solution Overview
Problem
Existing burners have fixed combustion surface areas and orifice sizes, limiting their ability to achieve low heat output settings efficiently, leading to high cycling frequencies, energy losses, and long start-up times due to the need for periodic shut-off, which fails to accommodate varying heating demands effectively.
Innovation Solution
A high turn-down burner design that adjusts its effective combustion area by regulating fuel flow pressure through a sliding disk mechanism or rotatable inner housing, allowing for optimal fuel distribution and combustion surface area modification without external power, ensuring sustained combustion at low flowrates and efficient heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the burner uses a fixed combustion surface area, then the structure is simple, but the burner cannot support combustion at very low combustion rates
Solution Approach 1:
The patent employs a movable disk that can be positioned at different heights within the supply tube to dynamically adjust the combustion surface area. The disk's position is controlled by fuel flow pressure, allowing the burner to adapt to varying combustion rates from very low to high levels. This dynamic adjustment mechanism resolves the contradiction by enabling combustion rate adaptability while maintaining a relatively simple overall structure.
Solution Approach 2:
The invention changes the parameter of combustion surface area by varying the exposed area of the disk's lower surface. As the disk moves vertically, different portions of its lower surface are exposed to the fuel flow, thereby changing the effective combustion area. This parameter change allows the burner to support a wide range of combustion rates without requiring complex multiple-component systems.
2Adaptability or versatility
If the burner is shut off periodically to achieve high turn-down at low heat output, then the turn-down ratio is improved, but energy losses and cycling frequency increase
Solution Approach 1:
The patent enables continuous combustion operation across a wide heat output range by adjusting the combustion surface area rather than shutting off the burner. The movable disk allows the burner to maintain steady combustion at low heat outputs by reducing the active combustion area, eliminating the need for periodic shut-off and start-up cycles. This continuous operation principle resolves the contradiction by achieving high turn-down ratio without the energy losses associated with cycling.
3Adaptability or versatility
If the combustion surface area is reduced to support low combustion rates, then the minimum heat output is lowered, but the burner cannot respond quickly to sudden load demands
Solution Approach 1:
The movable disk responds dynamically to changes in fuel flow pressure, automatically adjusting the combustion surface area in real-time. When fuel flow pressure increases suddenly, the disk is pushed upward to expose more combustion area, enabling rapid response to load demands. Conversely, when fuel flow decreases, the disk moves downward to reduce the combustion area, maintaining efficient combustion at low outputs. This dynamic response mechanism resolves the contradiction between low minimum heat output and fast response speed.
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 achieves a high turn-down ratio with efficient combustion and reduced energy losses by dynamically adjusting the combustion area based on fuel flow, preventing overheating and maintaining precise temperature control, even at low firing rates, thus enhancing responsiveness to heating demands.
Implementation Method 1
the fuel flow is configured to exert a force equivalent to the weight of the disk thereby sustaining an optimal flowrate of the fuel flow through a plurality of apertures below the disk
Data Source
AI summary
A high turn-down burner adapted to receive a fuel flow for combustion including an outer housing including a central axis, a side wall having a top edge and a bottom edge, a plurality of apertures disposed on the side wall, a top wall adjoining the side wall at the top edge and a bottom wall adjoining the side wall at the bottom edge; an inner housing including a central axis, a side wall, a plurality of apertures disposed on the side wall, the inner housing is coaxially rotatable with respect to the outer housing; and an actuator adapted to harness and convert the power exerted by the fuel flow to a movement of the inner housing with respect to the outer housing, wherein the alignment of the apertures of the inner and outer housings is adapted to modify an effective combustion area of the burner.