Modulating Burner Vacuum Control for Continuous Firing Rates
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Solution Overview
Problem
Current burner control systems for radiant tube heating devices cannot continuously vary fuel pressure and firing rate, limiting their ability to precisely control temperature by only allowing discrete firing rates.
Innovation Solution
A modulating burner system utilizing pneumatic gas amplifying valves with dampers to stabilize vacuum and air pressure differentials, enabling continuous variable control of gas flow and firing rates between 50% to 100% of the burner's capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a multi-stage fuel regulator is used to achieve discrete firing rates, then the burner can operate at multiple predetermined pressures, but continuous variable control of fuel pressure and firing rate cannot be achieved
Solution Approach 1:
The patent replaces the mechanical multi-stage fuel regulator system with a pneumatic control system using gas amplifying valves. This pneumatic system uses vacuum pressure differentials to control gas flow, enabling continuous variable modulation of firing rates rather than discrete predetermined stages.
Solution Approach 2:
The invention employs pneumatic principles by using vacuum pressure differentials created by a blower to control gas amplifying valves. The vacuum pressure varies continuously with blower speed, providing continuous modulation of fuel gas flow and enabling smooth firing rate control from 50% to 100% capacity.
2Ease of operation
If blower vacuum is used to control gas amplifying valves, then firing rate can be modulated, but oscillations and pulsations from the blower prevent proper modulating control
Solution Approach 1:
The patent introduces a vacuum reservoir as an intermediary between the blower and the gas amplifying valves. The reservoir acts as a buffer that smooths out vacuum oscillations and pulsations from the blower, providing stable vacuum pressure for precise gas flow control while maintaining the ability to modulate firing rates.
Solution Approach 2:
The vacuum reservoir provides beforehand cushioning by storing vacuum pressure and releasing it smoothly to compensate for blower oscillations. This cushioning effect stabilizes the vacuum pressure before it reaches the gas amplifying valves, enabling proper modulating control.
3Device complexity
If discrete firing rates are used instead of continuous modulation, then the system is simpler to control, but temperature control precision is limited
Solution Approach 1:
The patent implements dynamic control by linking gas amplifying valve modulation to variable blower speed. The system continuously adjusts firing rates based on temperature differential signals, providing precise temperature control through dynamic modulation rather than static discrete stages, while maintaining relatively simple control logic.
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 allows for precise control of firing rates, ensuring a consistent air-fuel ratio and smooth operation by dampening oscillations and pulsations from the blower, effectively modulating the burner's output over a range of capacities.
Implementation Method 1
A vacuum is obtained off of blower 104 at a vacuum takeoff 112 and this vacuum is communicated through a vacuum conduit 114 and through a first damper 116 and onto a connection at a first port 118 of the gas amplifying valve 106
Implementation Method 2
The applicant discovered the use of dampers within the control circuit, in this case first damper 116 and second damper 132. These dampers were found to provide a uniform vacuum within the control circuits
Implementation Method 3
A vacuum is obtained off of blower 104 at a vacuum takeoff 112
Implementation Method 4
ensuring that there is a proper air fuel ratio being maintained and the firing rate of burner 102 is increased
Data Source
AI summary
A modulating burner system includes a speed control responsive to inputs received from a thermostat. The speed control modulating a blower which provides combustion air and a vacuum proportional to the speed of the blower. The modulating burner system further includes a gas amplifying valve in communication with the vacuum via a vacuum conduit. The gas amplifying valve providing modulated combustion gas responsive to the vacuum; wherein modulated combustion air and gas communicated to a burner for continuously variable firing rates of 50 to 100% of the maximum firing rate. The modulating burner system further includes control circuit dampers for smoothing out vacuum spikes and fluctuations.